tag:blogger.com,1999:blog-29876216163455014462024-03-28T04:56:54.575+05:30MarineSite.InfoA complete site for marine exams mainly concentrated on Meo Exams. A Complete Marine Engineering Guide
Sreelekshmihttp://www.blogger.com/profile/00682321255944973631noreply@blogger.comBlogger461125tag:blogger.com,1999:blog-2987621616345501446.post-31783963107069175742023-05-23T20:19:00.000+05:302023-05-23T20:19:20.572+05:30What Are The Cylinder Liner Checks During Scavenge Inspection?<p><span style="font-family: verdana;"><b> Visual Inspection:</b> Start by visually inspecting the cylinder liners for any signs of damage, such as cracks, scoring, or excessive wear. Look for indications of overheating or corrosion as well. Pay close attention to the liner surfaces, flanges, and cooling water passages.</span></p><p><span style="font-family: verdana;"><b>Scuffing and Scoring Analysis:</b> Check for scuffing or scoring marks on the liner surface. These marks may indicate issues with lubrication, fuel quality, or abnormal operating conditions. Assess the severity of the marks and determine if corrective action is required.</span></p><p><span style="font-family: verdana;"><b>Piston Ring Grooves: </b>Examine the piston ring grooves in the liner for wear, deposits, or damage. Excessive wear can lead to poor sealing and reduced engine performance. If required, clean the ring grooves and inspect or replace the piston rings. Use a feeler gauge to measure the clearances.</span></p><p><span style="font-family: verdana;"><b>Lubrication Assessment:</b> Evaluate the lubrication system and its effectiveness in providing adequate lubrication to the liner surfaces. Ensure that the lubricating oil is of the correct grade and viscosity for the engine operating conditions.</span></p><p><span style="font-family: verdana;"><b>Corrosion Inspection: </b>Check for signs of corrosion on the liner surfaces. Corrosion can be caused by the ingress of acidic combustion by-products or improper cooling water quality. Take necessary measures to prevent or mitigate corrosion, such as adjusting the cooling water treatment or addressing fuel quality issues.</span></p><p><span style="font-family: verdana;"><b>Documentation:</b> Maintain a record of the inspection findings for each cylinder liner. Document measurements, observations, and any necessary maintenance or corrective actions taken. This record will help track the condition of the liners over time and aid in future inspections.</span></p><p><br /></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-54173027672868537292023-05-23T20:06:00.002+05:302023-05-23T20:06:10.232+05:30Why Does a Piston Seize? What Action will You Take if Main Engine Piston is About to Seize?<p><span style="font-family: verdana;"> A piston can seize in a marine engine due to various reasons, including:</span></p><p><span style="font-family: verdana;"><b>Insufficient Lubrication: </b>If the piston does not receive an adequate supply of lubricating oil, the friction between the piston and cylinder wall increases, leading to overheating and potential seizure.</span></p><p><span style="font-family: verdana;"><b>Overheating:</b> Excessive heat within the combustion chamber can cause the piston to expand beyond its designed tolerances. This can result from factors such as coolant system failure, incorrect fuel-air mixture, or prolonged high-load operation.</span></p><p><span style="font-family: verdana;"><b>Contaminants:</b> The presence of foreign particles or contaminants in the engine oil can cause abrasive wear on the piston and cylinder wall, leading to increased friction and the potential for seizure.</span></p><p><span style="font-family: verdana;"><b>Improper Clearances: </b>If the piston-to-cylinder clearance is not within the specified limits, either too tight or too loose, it can affect proper lubrication and thermal expansion, increasing the risk of seizure.</span></p><p><span style="font-family: verdana;"><b>What Action will You Take if Main Engine Piston is About to Seize?</b></span></p><p><span style="font-family: verdana;"><b>Shut down the engine:</b> If you think your piston is about to seize, the first thing you should do is shut down the engine. This will help to prevent further damage.</span></p><p><span style="font-family: verdana;"><b>Check the oil level:</b> Once the engine is shut down, check the oil level. If the oil level is low, add oil until it reaches the correct level.</span></p><p><span style="font-family: verdana;"><b>Inspect the piston:</b> If you can, inspect the piston for damage. If the piston is damaged, it will need to be replaced.</span></p><p><span style="font-family: verdana;"></span></p><p><span style="font-family: verdana;"><b>Change the oil:</b> Once you have inspected the piston, change the oil. This will help to remove any contaminants that may have caused the piston to seize.</span></p><p><span style="font-family: verdana;"><br /></span></p><p><span style="font-family: verdana;"><br /></span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-61166907934262198522023-05-23T19:46:00.001+05:302023-05-23T19:46:09.330+05:30What are The Forces Acting On Tie Rods?<p><span style="font-family: verdana;"><b>Tensile force:</b> The tensile force is the force that pulls the tie rod apart. It is caused by the firing pressure of the cylinders. The firing pressure is the force that is generated when the fuel ignites in the cylinder. This force pushes down on the piston, which in turn pushes down on the connecting rod, which in turn pushes down on the crankshaft. The crankshaft then transmits this force to the tie rods. The tie rods must be strong enough to withstand this force without bending or breaking.</span></p><p><span style="font-family: verdana;"><b>Compressive force:</b> The compressive force is the force that pushes the tie rod together. It is caused by the weight of the engine and the forces generated when the engine is running. The weight of the engine is the force that pulls down on the engine block. The forces generated when the engine is running are the forces that are created by the pistons moving up and down in the cylinders. These forces push up on the engine block. The tie rods must be strong enough to withstand these forces without bending or breaking.</span></p><p><span style="font-family: verdana;"><b>Torsional force:</b> The torsional force is the force that twists the tie rod. It is caused by the forces generated when the engine is running. The forces generated when the engine is running are the forces that are created by the pistons moving up and down in the cylinders. These forces cause the engine to rotate. The tie rods must be strong enough to withstand these forces without bending or breaking.</span></p><p><span style="font-family: verdana;"><b>Bending force:</b> The bending force is the force that bends the tie rod. It is caused by the forces generated when the engine is running. The forces generated when the engine is running are the forces that are created by the pistons moving up and down in the cylinders. These forces cause the engine to bend. The tie rods must be strong enough to withstand these forces without bending or breaking.</span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-34158382125927713332023-01-29T13:08:00.001+05:302023-01-29T13:08:36.701+05:30How does low sea water temperature effect fresh water generation? Low sea water temperature can affect the efficiency of fresh water generation through distillation, a process that uses heat to vaporize seawater and then condense the resulting steam into fresh water. The effects of low sea water temperature on distillation include:<div><br></div><div>Reduced efficiency: Lower temperature seawater has less thermal energy, making it more difficult to vaporize. This can lead to a decrease in the amount of fresh water produced, longer distillation times, and increased energy consumption.</div><div><br></div><div>Increased scaling: Cold seawater can cause mineral scaling on the heat transfer surfaces, reducing the efficiency of heat transfer and making it more difficult to vaporize the seawater.</div><div><br></div><div>Increased fouling: Cold seawater can also cause fouling of the heat transfer surfaces, reducing the efficiency of heat transfer and the performance of the distillation system.</div><div><br></div><div>To mitigate these effects, ship operators may need to take steps to warm the seawater before it enters the distillation system, such as using a heat exchanger, or install additional pre-treatment systems to prevent fouling. These measures can help maintain the efficiency of fresh water generation and reduce operating costs</div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-10952840242490194082021-09-05T18:53:00.004+05:302021-09-05T22:14:11.415+05:30What is Water Hammering and How Will You Prevent it?<p><b><span style="font-family: verdana; font-size: large;">What is Water Hammering?</span></b></p><p><span style="font-family: verdana; font-size: large;"> When steam contact with cold area of the pipeline or in contact with water, it condenses and create vaccum, Which forces the water towards opened valve at high velocity and hit the valve with high speed make hammering sound.</span></p><p><b><span style="font-family: verdana; font-size: large;">How to Prevent Water Hammering?</span></b></p><p><span style="font-family: verdana; font-size: large;">> Drain the line before allowingsteam to the pipeline</span></p><p><span style="font-family: verdana; font-size: large;">> Slowly allow the steam by opening steam valve sowly</span></p><p><span style="font-family: verdana; font-size: large;">> Install steam trap in the line.</span></p><p><br /></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-89931447188569474022021-08-26T09:30:00.002+05:302021-09-05T16:49:10.553+05:30Oil In Cascade Tank (Hot well) Cause And Action<div><b><span style="font-family: verdana; font-size: large;">Cause</span></b></div><div><span style="font-family: verdana; font-size: large;">> Most probable cause is leaky fuel oil heaters. Any leaks in oil heaters leads oil in cascade tank.</span></div><div><span style="font-family: verdana; font-size: large;">> Deck cargo tank steam line leak</span></div><div><span style="font-family: verdana; font-size: large;"><br /></span></div><div><b><span style="font-family: verdana; font-size: large;">Action</span></b></div><span style="font-family: verdana; font-size: large;">> Reduce load on boiler</span><div><span style="font-family: verdana; font-size: large;">> Keep a watch on Observation tank oil level</span></div><div><span style="font-family: verdana; font-size: large;">> With proper PPE Open top cover of Cascade tank.</span></div><div><span style="font-family: verdana; font-size: large;">> If less oil, drain it from top or add a chemical that breaks the oil infine particles.</span></div><div><span style="font-family: verdana; font-size: large;">> If more oil, manually remove it by absorband pads or remove it by weldon pump from top.</span></div><div><span style="font-family: verdana; font-size: large;">> In no case emulsified water to go in boiler.</span></div><div><span style="font-family: verdana; font-size: large;">> Once leak identified shut down boiler if necessary.</span></div><div><span style="font-family: verdana; font-size: large;">> Shut the I/L valve to Atm. Condensor.</span></div><div><span style="font-family: verdana; font-size: large;">> Check Atm.Condensor drain for oil traces in atm. Condensor. If yes flush it completely.</span></div><div><span style="font-family: verdana; font-size: large;">> Check boiler water condition from sampling line. Find out if any oil present in boiler.If yes Do a Scum blow down.</span></div><div><span style="font-family: verdana; font-size: large;">> Take a sample again, if oil traces that means boiler too much contaminated, then completely blow down the boiler.</span></div><div><span style="font-family: verdana; font-size: large;">> Make sure Of MARPOL ANNEX 1 in this case.</span></div><div><span style="font-family: verdana; font-size: large;">> Oil content to be <15 ppm Or We would have to drain in Bilges or Collect it in a seperate drum then give it to Port reception.</span></div><div><span style="font-family: verdana; font-size: large;">> Flush clascade tank after cleaning</span></div><div><span style="font-family: verdana; font-size: large;">> Flush Boiler with FW</span></div><div><span style="font-family: verdana; font-size: large;">> Check cascade water samples</span></div><div><span style="font-family: verdana; font-size: large;">> Once all samples ok Take water in cascade tank </span></div><div><span style="font-family: verdana; font-size: large;">> Take water in boiler</span></div><div><span style="font-family: verdana; font-size: large;">> Do Cold firing</span></div><div><span style="font-family: verdana; font-size: large;">> Increase the load slowly </span></div><div><span style="font-family: verdana; font-size: large;">> See how much time it takes for the steam to rise.</span></div><div><span style="font-family: verdana; font-size: large;">> If it takes more time, that means oil is still present and will take more time to raise steam.</span></div><div><span style="font-family: verdana; font-size: large;">> Proceed further according to action req.</span></div><div><span style="font-family: verdana; font-size: large;"><br /></span></div><div><div><b><span style="font-family: verdana; font-size: large;">How to Find Out Leaks</span></b></div><div><span style="font-family: verdana; font-size: large;">> If ER leak check heaters= open heater drains and confirm.</span></div><div><span style="font-family: verdana; font-size: large;">> If ER tanks heaters leak = open the steam trap drain and confirm.</span></div><div><span style="font-family: verdana; font-size: large;">> If Deck cargo tank steam lines leak = open return lines and check on deck.</span></div><div><span style="font-family: verdana; font-size: large;">> If a Observation tank is given on deck, then check there.</span></div></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-87688236119404465632021-07-06T20:13:00.002+05:302021-07-06T20:13:12.143+05:30Basic Terms In Marine Refrigeration System<div style="text-align: left;"><b><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;">Which Refrigerants Used Nowadays?</span></span></b></div><span id="docs-internal-guid-e61ba160-7fff-2219-1843-ba5bf502aaf3"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> Freon 11&amp;12 are CFC and are banned now; Freon 22 are HCFC and can be utilized by 1 st Jan 2020; and only HFC-133, HFC-134, HFC-404 will be in use later</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">What is relative humidity ?</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Ratio of amount of water vapour in given volume of air, to maximum amount of water vapour that can be present before precipitation occurs.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> It is the mass of water vapour per unit volume of air compared to the mass of water vapour per unit volume of saturated air at the same temperature.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">What is critical temperature ?</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Critical temperature is the temperature above which it is impossible to liquefy the refrigerant regardless of pressure.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> It should be as high as possible and certainly above the maximum expected condenser temperature.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">What is saturated air ?</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">The air contains maximum weight of water vapour at the particular temperature.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">What is superheating ?</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">Keeping refrigerant at a temperature above the saturated temperature.</span></span></p><div><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-65401079229590401212021-07-06T20:10:00.001+05:302021-07-06T20:10:05.400+05:30Procedure for Starting and Stopping of Refrigeration Plant?<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"><b>Starting</b></span></span></div><span id="docs-internal-guid-74a4442a-7fff-b014-b72f-8971ad5af38b"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check oil level in the compressor.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the condenser cooling valves, close the drain cock and start cooling water pump</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: verdana; font-size: medium;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> Open all the refrigeration system valves except the compressor suction valve. ensure </span><span style="white-space: pre-wrap;">that compressor discharge is open .</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Start Blower and put the solenoid valve in auto</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> check power supply to the compressor and solenoid valves.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Now open the suction valve of the compressor and start the compressor.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: verdana; font-size: medium;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> observe the system for any abnormal operation for ten minutes before putting it in </span><span style="white-space: pre-wrap;">“auto-mode”</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: verdana; font-size: medium;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline;"><span style="white-space: pre-wrap;">> The system generally operates automatically once started. If the temp., in </span></span><span style="white-space: pre-wrap;">the room rises, solenoid valve opens and the refrigerant then </span><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">flows through the evaporator through the expansion valve. As the refrigerant flows through the evaporator, </span><span style="white-space: pre-wrap;">compressor suction pressure begins to rise. This suction pressure is sensed by the “lpco” </span><span style="white-space: pre-wrap;">which cuts-in at it’s high pressure setting and starts the compressor.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> When the intended cold temp., is reached, the thermostat closes the solenoid valve.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: verdana; font-size: medium;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> Compressor continue running, unloading the cylinders until the suction pressure is </span><span style="white-space: pre-wrap;">low enough to actuate low pressure cut off (LPCO). When set pressure is reached the “lpco” switch stops the compressor.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Stopping </span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Refrigeration plan cut in and cut off automatically here below the procedure for manual stopping</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the discharge valve of the condenser.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> When the compressor suction pressure below set point compressor will be cut off by low pressure cut off</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> When the compressor suction side pressure come up it will run for some time and cut off let it do the same process 2 time and allow whole refrigerant in condenser</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the suction and discharge valve of compressor</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Switch off the breaker.</span></span></p><div><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></div></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-8894527687993585142021-07-06T20:06:00.001+05:302021-07-06T20:06:30.753+05:30How to Charge Refrigeration Plant on Ships?<p><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;">Charging can be done by two method,</span></span></p><span id="docs-internal-guid-f06072bf-7fff-be05-8cb0-f86cd184a998"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > Vapour charging</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > Liquid Charging</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Vapour charging</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> In vapour charging vapour refrigerant introduced in the suction side of the compressor</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Liquid Charging</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> In Liquid charging liquid refrigerant charge through the charging point provided near the receiver.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> </span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Procedure</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Kept the charging Bottle on weighing machine note down the weight</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Connect the bottle to charging valve with connection pipe</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Before connecting to the charging valve remove air by crack open the bottle</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Tighten the cap and open bottle valve fully, charging valve is still closed</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Change compressor to manual running and start it</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the condenser outlet valve</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the charging valve slowly when suction pressure is just above zero.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Control the valve opening slowly</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Monitor the level through condenser sight glass</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the charging valve</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> pumping down the entire charge until suction pressure just above zero</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Stop the compressor and close the discharge valve.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Cooling water kept running for an hour.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Purge air through the purging valve provided on condenser top</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Calculate the amount of refrigerant by weighing the cylinder.</span></span></p><br /></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-9919823779437283082021-07-06T19:59:00.009+05:302021-07-06T19:59:57.046+05:30What are The Symptoms And Remedies of Over Charging And Under Charging<div style="text-align: left;"><span style="white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Over Charging</span></b></span></div><span id="docs-internal-guid-7830bd99-7fff-ba1e-6078-41a59b0c5912"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Symptoms</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Compressor runs cold.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> High compressor discharge pressure.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Excess frost on compressor suction line after evaporator.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Sight glass shows full of refrigerant</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Remedies</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Collect excess refrigerant gas to collecting bottle</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Under Charging</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Low discharge pressure</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Large bubbles in the liquid sight glass</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Compressor delivery temperature high.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Compressor continuously run without cut off or the cutoff interval will be too long</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Remedies</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> To charge the refrigerant until the bubbles disappear in the liquid sight glass and charging will correct the pressure gauge reading.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> To find out the leaky points by halide torch or soap solution or electronic leak detector.</span></span></p><br /></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-65160278806295582732021-07-06T19:39:00.003+05:302021-07-06T19:39:44.973+05:30Explain Marine Refrigeration System With simple Diagram<p> </p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEMo4vqvEvUMwkdLyTObSUZnja9d8sl9kgE3fhIlchvfPsQ7LSWWNFCaC1ppGTLid-hoKi9RnLts0kGMdVCWH1TX02vYjftPLyaFmUXflGvIyCyhyixQQcXzgaSwq2E4ocl-IoFfbzaTY/s1177/SmartSelect_20210706-193201.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="832" data-original-width="1177" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEMo4vqvEvUMwkdLyTObSUZnja9d8sl9kgE3fhIlchvfPsQ7LSWWNFCaC1ppGTLid-hoKi9RnLts0kGMdVCWH1TX02vYjftPLyaFmUXflGvIyCyhyixQQcXzgaSwq2E4ocl-IoFfbzaTY/w640-h452/SmartSelect_20210706-193201.jpg" width="640" /></a></div><br /><p></p><p><span style="font-family: Arial; font-size: 11pt; white-space: pre-wrap;"><b>Components </b></span></p><p><span style="font-family: Arial; font-size: 11pt; white-space: pre-wrap;"><b>> Compressor: </b>Reciprocating single or two stage compressor is commonly used for compressing and supplying the refrigerant to the system.</span></p><span id="docs-internal-guid-29ece728-7fff-5971-f424-425a1f0b6455"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Condenser: </b>Shell and tube type condenser is used to cool down the refrigerant in the system.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Receiver:</b> The cooled refrigerant is supplied to the receiver, which is also used to drain out the refrigerant from the system for maintenance purposes.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Drier:</b> The drier connected in the system consists of silica gel to remove any moisture from the refrigerant</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Solenoids:</b> Different solenoid valves are used to control the flow of refrigerant into the hold or room. Master solenoid is provided </span><span style="font-family: Arial; font-size: 11pt; white-space: pre-wrap;">in the main line and other solenoids are present in all individual cargo holds or rooms.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Expansion valve:</b> An Expansion valve regulates the refrigerants to maintain the correct hold or room temperature.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><br /></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Evaporator unit: </b>The evaporator unit acts as a heat exchanger to cool down the hold or room area by transferring heat to the refrigerant.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> HP and LP cut out:</b> LP cut out is controlled automatically i.e. when the suction pressure drops, the compressor stops and when the suction pressure rises again, the control system starts the compressor. HP or high pressure cut out is provided with manually reset</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-family: Arial; font-size: 11pt; font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>> Oil Differential Pressure switch</b> compares the measured lubricating oil pressure to the Suction (crankcase) pressure. Should the differential pressure fall below a pre-set minimum (about 1.2 bar) then the compressor will trip and require a manual reset to restart. A time delay is built into the circuit to allow sufficient time for the lubricating oil pressure to build up when starting before arming the circuit.</span></p><br /></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-66891278919652658052021-07-01T20:26:00.001+05:302021-07-06T20:39:21.186+05:30Simple Notes For Marine Refrigeration System | Guide<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span> </span><span style="background-color: white;">It is a complete guide for Marine Refrigeration System on ship. This is a good collection of notes prepared in the purview of Marine exams in a simple and easy understandable language with bullet points.</span></span></div><a name='more'></a><span style="font-family: verdana; font-size: medium;">As it is impossible to answer all questions at a time it is done on timely basis. please comment below or contact on admin@marinesite.info, once you find any important area, missed out. Also contact us, if you wish to answer any of the questions listed.</span><div><span style="font-family: verdana; font-size: medium;"><br /></span><div><span style="font-family: verdana; font-size: medium;"><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"><b>Refrigeration</b></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"><b>Basics</b></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="https://www.marinesite.info/2021/07/basic-terms-in-marine-refrigeration.html">Basic Terms In Marine Refrigeration System</a></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/10/principle-of-refrigeration.html">Principle Of refrigeration With Simple Diagram</a> </span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="Explain Marine Refrigeration System With simple Diagram">Explain Marine Refrigeration System With simple Diagram</a></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2014/01/the-working-of-thermostatic-expansion.html">Thermostatic Expansion Explain with Simple Diagram</a> </span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/11/why-back-pressure-valve-in.html">Use Of Back pressure valve In Refrigeration System</a> </span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2014/04/lube-oil-properties_12.html">Refrigerator LO properties </a></span></div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/09/ideal-properties-for-refrigerant.html">Properties of Refrigerant</a> </span><div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2012/02/what-is-super-heating-in-refrigeration.html">What is super heating in refrigeration system</a> </span></div><div><span style="font-family: verdana; font-size: medium;">> PH diagram of refrigeration cycle</span><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><span style="font-family: verdana; font-size: medium;"><b>Procedures</b><br /></span><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="https://www.marinesite.info/2021/07/procedure-for-starting-and-stopping-of.html">Procedure for Starting and Stopping of Refrigeration Plant</a>?</span></span></div><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="https://www.marinesite.info/2021/07/how-to-charge-refrigeration-plant-on.html">How to Charge Refrigeration Plant on Ships?</a> </span></span></div><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="http://www.marinesite.info/2014/03/troubleshoot-presence-of-air-in.html">Air in refrigeration system indication and procedure to remove</a> </span><br /><span>><a href="http://www.marinesite.info/2017/11/refrigerant-leak-detection-methods-in.html"> Leak detection methods in refrigeration and A/c System</a></span></span></div><div><br /></div><div><span style="font-family: verdana; font-size: medium;"><b>Alarm And Safeties</b></span></div><div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2017/11/safeties-in-refrigeration-and-ac-system.html">Safeties in Refrigeration system</a></span></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><span style="font-family: verdana; font-size: medium;"><b>Troubleshooting</b><br /><span>> <a href="http://www.marinesite.info/2017/11/short-cycling-in-refrigeration-system-ac.html">Short Cycling in refrigeration and A/C</a> </span></span></div><div><span style="font-family: verdana; font-size: medium;">> <a href="https://www.marinesite.info/2021/07/what-are-symptoms-and-remedies-of-over.html">What are The Symptoms And Remedies of Over Charging And Under Charging</a></span></div></div></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div></span></div></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-56847628344211671932021-07-01T09:08:00.003+05:302021-07-06T20:39:45.148+05:30Marine Refrigeration Important MEO Class 4 Topics<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> Here I have tried my level best to list almost all possible questions from Marine Refrigeration System And Air-conditioning. As it is impossible to answer all questions at a time I am doing it on timely basis. If you find that I have missed out any questions, please hint me by commenting below or mail at admin@marinesite.info. Repeatedly asked questions marked as V.imp and Imp so please do give special attention for those questions</span></div><span style="font-family: verdana; font-size: medium;"><span><a name='more'></a></span></span><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"> If interested in answering unanswered questions please do mail us admin@marinesite.info. Your small contribution can make a big change in someone’s life</span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"><br /></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"><b>Refrigeration</b></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;"><b>Basics</b></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="https://www.marinesite.info/2021/07/basic-terms-in-marine-refrigeration.html">Basic Terms In Marine Refrigeration System</a></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/10/principle-of-refrigeration.html">Principle Of refrigeration With Simple Diagram</a> (Imp)</span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="Explain Marine Refrigeration System With simple Diagram">Explain Marine Refrigeration System With simple Diagram</a></span></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2014/01/the-working-of-thermostatic-expansion.html">Thermostatic Expansion Explain with Simple Diagram</a> (Imp)</span></div><div dir="ltr" trbidi="on"><div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/11/why-back-pressure-valve-in.html">Use Of Back pressure valve In Refrigeration System</a> (Imp)</span></div></div><div dir="ltr" trbidi="on"><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2014/04/lube-oil-properties_12.html">Refrigerator LO properties </a>(Imp)</span></div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2013/09/ideal-properties-for-refrigerant.html">Properties of Refrigerant</a> (Imp)</span><div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2012/02/what-is-super-heating-in-refrigeration.html">What is super heating in refrigeration system</a> (V.Imp)</span></div><div><span style="font-family: verdana; font-size: medium;">> PH diagram of refrigeration cycle</span><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><span style="font-family: verdana; font-size: medium;"><b>Procedures</b><br /></span><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="https://www.marinesite.info/2021/07/procedure-for-starting-and-stopping-of.html">Procedure for Starting and Stopping of Refrigeration Plant</a>?</span></span></div><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="https://www.marinesite.info/2021/07/how-to-charge-refrigeration-plant-on.html">How to Charge Refrigeration Plant on Ships?</a> (Imp)</span></span></div><div><span style="font-family: verdana; font-size: medium;"><span>> <a href="http://www.marinesite.info/2014/03/troubleshoot-presence-of-air-in.html">Air in refrigeration system indication and procedure to remove</a> (Imp)</span><br /><span>><a href="http://www.marinesite.info/2017/11/refrigerant-leak-detection-methods-in.html"> Leak detection methods in refrigeration and A/c System</a></span></span></div><div><br /></div><div><span style="font-family: verdana; font-size: medium;"><b>Alarm And Safeties</b></span></div><div><span style="font-family: verdana; font-size: medium;">> <a href="http://www.marinesite.info/2017/11/safeties-in-refrigeration-and-ac-system.html">Safeties in Refrigeration system</a></span></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><span style="font-family: verdana; font-size: medium;"><b>Troubleshooting</b><br /><span>> <a href="http://www.marinesite.info/2017/11/short-cycling-in-refrigeration-system-ac.html">Short Cycling in refrigeration and A/C</a> (imp)</span></span></div><div><span style="font-family: verdana; font-size: medium;">> <a href="https://www.marinesite.info/2021/07/what-are-symptoms-and-remedies-of-over.html">What are The Symptoms And Remedies of Over Charging And Under Charging</a> (V.imp)</span></div><div><span style="font-family: verdana; font-size: medium;"><br /><br /></span></div></div></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-72478311773636634152021-06-30T10:20:00.007+05:302021-06-30T10:21:26.542+05:30Marine Sewage Treatment Plant (STP) Simple Guide | Notes<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="background-color: white;"> </span><span style="background-color: white;">It is a complete guide for Sewage Treatment Plant (STP) onboard ship. This is a good collection of notes prepared in the purview of Marine exams in a simple and easy understandable language with bullet points.</span></span></div><a name='more'></a><span style="font-family: verdana; font-size: medium;"> As it is impossible to answer all questions at a time it is done on timely basis. please comment below or contact on admin@marinesite.info, once you find any important area, missed out. Also contact us, if you wish to answer any of the questions listed.</span><div><span style="font-family: verdana; font-size: medium;"><br /></span><div><span style="font-family: verdana; font-size: medium;"><div><b><span style="font-family: verdana; font-size: medium;">Basics</span></b></div><div><span style="font-family: verdana; font-size: medium;"><span face="Verdana, sans-serif">> <a href="https://www.marinesite.info/2021/06/marine-sewage-treatment-plant-on-ship.html">Explain Working Principle of STP with the help of diagram</a> </span><br /><span face="Verdana, sans-serif">> <a href="http://www.marinesite.info/2013/12/what-is-bod.html">What is BOD ( Biological Oxygen Demand)?</a> </span><br /><span face="Verdana, sans-serif">> Why anaerobic bacteria is not used in STP?</span><br /><span face="Verdana, sans-serif">> <a href="http://www.marinesite.info/2015/08/siphon-vented-loops-or-anti-siphon-vv.html">Why there is a vented loop or Anti-siphon tube after STP and before overboard Valve?</a> </span></span></div><div><span style="font-family: verdana; font-size: medium;"><span face="Verdana, sans-serif">> What are the tests in STP</span></span></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><span style="font-family: verdana; font-size: medium;"><b>Maintenance</b></span></div><div><span style="font-family: verdana; font-size: medium;">> <a href="https://www.marinesite.info/2021/06/marine-sewage-treatment-plant.html">Sewage Treatment Plant Maintenance Routines</a><br /><br /></span><div style="-webkit-text-stroke-width: 0px; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; orphans: auto; widows: 1;"><b><span style="font-family: verdana; font-size: medium;">Troubleshooting</span></b></div><span style="font-family: verdana; font-size: medium;"><span face="Verdana, sans-serif">> Reason for STP blower failure and Action taken</span><br /><span face="Verdana, sans-serif">> Reason for grey colour discharge from STP?</span></span></div></span></div></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-84930800472658579072021-06-30T10:17:00.003+05:302021-06-30T10:17:22.161+05:30Marine Sewage Treatment Plant Maintenance<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"> Regular maintenance is required to ensure biological treatment process is running smoothly and there is no malfunctions with the risk of anaerobic process resulting formation of methane gas and toxic fumes<span><a name='more'></a></span></span></span></div><span id="docs-internal-guid-4d2c0064-7fff-6242-9f96-0681742818c9"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Daily</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check for any abnormal alarms</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check smell and abnormal noise from blower and pump</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check the sludge return flow from settling tank to aeration chamber </span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check the chemical dosing tank</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Weekly</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Take a sludge content test</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> check chlorine content of effluent </span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Monthly</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check aeration lines are clear. If solenoid valves are present check the working of the same.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Do backwash if the sludge content is high</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check that there is no obstruction in the venting line</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Inspect the tank’s external and internal coatings for corrosion</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Try out all the external valves</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Try out high level alarms</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Yearly </span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Empty whole system and clean thoroughly </span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Clean the floats for pump cut in and cut of as well as high level alarm</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Replace the gaskets if required</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Replace the non return valve in case of vacuum STP</span></span></p><br /></span>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-80315521274339462052021-06-30T09:58:00.002+05:302021-06-30T09:58:22.242+05:30Marine Sewage Treatment Plant On Ship Principle and Working<span id="docs-internal-guid-f38e2431-7fff-9af8-1247-b2cf0beeb980" style="font-family: verdana; font-size: medium;"><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> There are two methods used onboard to treat the sewage, chemical or biological methods. The chemical method is basically a storage tank which collects solid material for disposal in permitted areas or to a shore collection facility. The biological method treats the sewage so that it is acceptable for discharge inshore.<span></span></span></p><a name='more'></a><p></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The most preferred sewage treatment in ship is biological sewage treatment i.e., using aerobic bacteria. So we will discuss only biological treatment plants here.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>Principle</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The basic principle of a biological sewage treatment plant is decomposition of raw sewage with the help of aerobic bacteria. This is done by aerating the chamber with fresh air. The extended aeration process provides a climate in which oxygen-loving bacteria multiply and digest the sewage, converting it into a sludge. These oxygen-loving bacteria are known as aerobic bacteria.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQxd_ebQO7AMCyDktY79mV7rRqgSbeRnrpcx0PLtENON80ww9voRrmhln-fYALcIfdXomcTekelNI9qtI1X1ZGA6zksyr-5kUMG_2A2Wz_ASiPvlw4z95sEr1U-6kg6-CFO2hYxqykv68/s657/sewage+treatment+plant.PNG" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="505" data-original-width="657" height="492" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQxd_ebQO7AMCyDktY79mV7rRqgSbeRnrpcx0PLtENON80ww9voRrmhln-fYALcIfdXomcTekelNI9qtI1X1ZGA6zksyr-5kUMG_2A2Wz_ASiPvlw4z95sEr1U-6kg6-CFO2hYxqykv68/w640-h492/sewage+treatment+plant.PNG" width="640" /></a></div><p></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>Working</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">A typical ship STP is having 4 chambers</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> > Primary Chamber</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> Aeration Chamber</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> Settling Chamber</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;">> Chlorination Chamber</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b> Primary Chamber</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The row sewage enters the primary chamber via a coarse mesh filter where large solids are broken down. The advantage of breaking sewage in small particles is that it increases the area and a high number of bacteria can attack simultaneously to decompose the sewage. </span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>Aeration Chamber</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The sewage enters the aeration compartment where it is digested by aerobic bacteria and microorganisms. The aeration chamber is where the main biological action takes place. Here air blowers mounted on the outside of the unit oxygenate and stir the effluent and bacteria mix via a series of pipes and nozzles. The sewage remains in this aeration tank for some time.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The sewage is decomposed into carbon dioxide, water, and inorganic sewage</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>Settling Chamber</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The sewage then flows into the settling compartment where the activated sludge is settled out. Any solids that settle out are returned via an air lift to the aeration chamber which ensures that they are fully broken down. This returned sludge contains the bacteria to digest the incoming sewage.</span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><br /></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b>Chlorination Chamber</b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"> The clear liquid then overflows from the settling tank to the chlorination chamber, and the chlorinator disinfects the liquid. The chamber has float switches, which control the discharge pump, and a high level alarm.</span></p></span><div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> </span></div><div style="text-align: center;"><span style="font-family: verdana; font-size: medium;"><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="315" src="https://www.youtube.com/embed/uwW5S4yjsT8" title="YouTube video player" width="560"></iframe></span></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-68872573784110284022021-06-29T20:35:00.008+05:302021-06-30T10:31:41.578+05:30Starting and Stopping Procedure of Oily Water Separator (OWS)<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <b>STARTING</b></span></div><div><span style="font-family: verdana; font-size: medium;">> Get the permission from bridge (duty officer should know if OWS is running new ships having OWS master breaker on bride)</span></div><div><span style="font-family: verdana; font-size: medium;">> OWS overboard manual discharge valve is to be kept locked and keys are to be kept with the chief engineer or master. </span></div><div><span style="font-family: verdana; font-size: medium;">> Open the lock and overboard valve</span></div><div><span style="font-family: verdana; font-size: medium;">> Open all required valves for the operation</span></div><div><span style="font-family: verdana; font-size: medium;">> Open the desired bilge tank valve from which the oily water mixture is to be discharged from OWS</span></div><div><span style="font-family: verdana; font-size: medium;">> Open air if the control valves are air operated</span></div><div><span style="font-family: verdana; font-size: medium;">> Switch on the power supply of the control panel and OCM unit</span></div><div><span style="font-family: verdana; font-size: medium;">> Fill the separator and filter unit with fresh or sea water to clean up and prime the system until the water comes out from the vent of the second stage</span></div><div><span style="font-family: verdana; font-size: medium;">> Close the vents</span></div><div><span style="font-family: verdana; font-size: medium;">> Start the OWS supply pump</span></div><div><span style="font-family: verdana; font-size: medium;">> Monitor the OCM for ppm value and keep checking sounding of bilge tank from where the OWS is taking suction</span></div><div><span style="font-family: verdana; font-size: medium;">> Also check the sounding of the OWS sludge tank</span></div><div><span style="font-family: verdana; font-size: medium;">> A skin valve / sample valve is provided just before the overboard valve and after the 3-way valve. Keep a check on the sample for any effluent and clarity</span></div><div><span style="font-family: verdana; font-size: medium;">> Keep a watch on the ship side at the overboard discharge valve</span></div><div><span style="font-family: verdana; font-size: medium;">> Monitor the sounding at frequent intervals.</span></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div><b><span style="font-family: verdana; font-size: medium;">STOPPING</span></b></div><div><span style="font-family: verdana; font-size: medium;">> When the operation of bilge water overboard is finished, flush the OWS with sea / fresh water for at least 10 minutes</span></div><div><span style="font-family: verdana; font-size: medium;">> This is done to ensure that the oil mixture which resides in the separator may be prevented from getting decomposed</span></div><div><span style="font-family: verdana; font-size: medium;">> Open the oil drain valve manually and discharge the separated oil from the separator as much as possible</span></div><div><span style="font-family: verdana; font-size: medium;">> Turn off the electric / pneumatic supply for 3 ways and also of the drain valves</span></div><div><span style="font-family: verdana; font-size: medium;">> Turn off the power supply of oil content monitor</span></div><div><span style="font-family: verdana; font-size: medium;">> Flush the oil content monitor with fresh water and clean the same</span></div><div><span style="font-family: verdana; font-size: medium;">> Turn off the electrical supply to the bilge pump and shut its valves</span></div><div><span style="font-family: verdana; font-size: medium;">> Shut all the valves in the bilge pipeline going to the OWS</span></div><div><span style="font-family: verdana; font-size: medium;">> Lock the overboard valve</span></div><div><span style="font-family: verdana; font-size: medium;">> Inform bridge and Switch off the breaker from bridge</span></div><div><span style="font-family: verdana; font-size: medium;">> Keys should be handed over to the chief engineer</span></div><div><span style="font-family: verdana; font-size: medium;">> Entry is to be made by the chief engineer in the oil record book, along with the signature of the operating Engineer, the chief engineer and the master</span></div><div><span style="font-family: verdana; font-size: medium;"><br /></span></div><div>You Can Answer Following Procedure</div><div>> Describe the operating procedure of an oily water separator?</div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-12789664323167404332021-06-29T20:32:00.006+05:302021-06-29T20:32:46.359+05:30Different Types Of Filters Used In OWS<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <b>Type of Filters used in OWS </b></span></div><div><div class="MsoNormal" style="margin-left: 0.25in; mso-list: l0 level1 lfo1; tab-stops: list .25in; text-indent: -0.25in;"></div><span style="font-family: verdana; font-size: medium;"><b style="text-indent: -0.25in;"><span face="Verdana, sans-serif"><i> </i></span></b><br /><b style="text-indent: -0.25in;"><i> Coalescence type</i>:</b><br /></span><div class="MsoNormal"></div><ol><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"><b> </b>Hydrophilic material i.e. glass wool.</span></li><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"><b> </b>Absorbs water rather than oil.</span></li><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"> Has to be renewed after certain periods.</span></li></ol><div class="MsoNormal" style="margin-left: 0.25in; mso-list: l0 level1 lfo1; tab-stops: list .25in; text-indent: -0.25in;"></div><span style="font-family: verdana; font-size: medium;"><b style="text-indent: -0.25in;"><i> Absorption type</i>:</b><br /></span><div class="MsoNormal"></div><ol><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"><b> </b>Oleophilic material</span></li><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"><b> </b>Absorbs oil rather than water.</span></li><li><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium;"> Frequent replacement is not required.</span></li></ol><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium; text-indent: -0.25in;"><b>High rate of separation is favored by:</b></span></div><div><span face="Verdana, sans-serif" style="font-family: verdana; font-size: medium; text-indent: -0.25in;"><div> > Large size of oil globule.</div><div> > Elevated temperature of the system ( i.e. lowers viscosity of oil, density of oil-water but oil is higher).</div><div> > Residence time.</div><div> > Avoidance of turbulence or agitation.</div><div> > Laminar or stream line flow.</div><div> > Low viscosity of oil globule.</div></span></div>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-49899071346206680142021-06-28T14:46:00.007+05:302021-06-28T14:46:48.004+05:30What is Under Charge and Over Charge Condition in Hydrophore<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"><b>Under Charge</b></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> The pressure inside the hydrophore is below the rated pressure range and is called under charged condition. This condition is the result of air leaking from either; relief valve, isolation valve, air supply valve, vent valve or the gauge glass itself. The situation can be found with no water supply at the accommodation top.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Over Charge</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> The pressure inside the hydrophore above the rated pressure is called overcharged condition. This condition is because of a leak in the air supply valve. The situation can result in no water in the hydrophore tank in some cases and thus be reacted quickly with care.</span></span></p><br />Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-52467236875473744162021-06-28T14:35:00.009+05:302021-06-28T14:35:57.835+05:30Reasons For Continous running or Frequent Cut-in & Cut-off Hydrophore Pump<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"><b>Continuous running of the hydrophore pump</b></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Mainly continuous running of pump is due to the insufficient air pressure, so charge air as per manufacturer's instructions</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Due to wrong setting of pressure switches or faulty pressure switch.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Problems with pumps, such as loose suction, insufficient capacity, high water consumption rates etc.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Under Charge</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Frequently cut-in and cut-out of hydrophore</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Cut in and cut off the differential set too narrow</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Faulty pressure switch</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Vent is leaking</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Gauge is leaking</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Air is leaking from any damaged joint in the shell</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Under Charge</span></span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-56532184978616671742021-06-28T11:26:00.004+05:302021-06-28T11:26:34.978+05:30What is Priming In Freshwater Generator? Reasons<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"><b>What is Priming In Freshwater Generator? </b> </span></div><div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;">Salt water carried over in large quantities during operation of the fresh water generator is called priming.</span></span></div><div style="text-align: left;"><span style="white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></div><div style="text-align: left;"><span style="white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> <b>General reasons of the priming are:</b></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Level of salt water inside the shell is high. When the water level is high agitation due to boiling occurs and salt water may carry over along with the vapours.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> When the salt water brine density is too high, agitation of salt water occurs which results in priming.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Increased evaporation rate.</span></span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-78811773184585020222021-06-28T11:15:00.001+05:302021-06-28T11:15:45.910+05:30Fresh Water Generator Troubleshooting<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"><b>Low fresh water production</b></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> sea water pressure low because of Ships draft, choked filters, fault in pump etc.<span></span></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Level of brine is too high</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Faulty Ejector nozzle/ nozzle choked</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Incorrect feed</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> scale formation in evaporator or condenser</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> shell temperature is too high</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> condenser cooling water flow is reduced</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Condenser cooling water temp. too high</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Incorrect assembly of plates</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> improper vacuum dueto the leakage in plants like from pressure gauge, vent, distillate pump seal etc.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Vacuum is not maintaining</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Air leaks into the evaporator shell in large quantities and the air ejector cannot cope.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> The cooling water flow through the condenser is reduced or the cooling water temperature is high. This causes saturation temperature and hence saturation pressure within the condenser to rise.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > Malfunctioning of the air ejector.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > The flow rate of the heating medium increased and excess water vapour produced. Since this excess vapours cannot be condensed, shell pressure increases or vacuum falls.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Increase in Salinity of Freshwater</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Brine level inside the shell too high.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Leaking condenser tubes or plates.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Operation of evaporator near shore with contaminated feed water.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Shell temperature and pressure are too low.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Increased solubility of CO2 generated from the salt water due to reduced seawater temperature. This dissolved CO2 makes water acidic and conductivity of water increases. Hence salinometer shows increased salinity, which is a measure of conductivity and not the presence of salt.</span></span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-45580080522371744562021-06-28T11:01:00.008+05:302021-06-28T11:01:48.804+05:30Starting And Stopping Procedure Of FreshwaterGenerator<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"><b>Starting</b></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open seawater ejector pump suction, discharge and overboard valves. <span></span></span></span></p><a name='more'></a><p></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Start the ejector pump, discharge pressure must be more than 3bar.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Wait for the vacuum to build up inside the fresh water generator shell. (About 92 % vacuum).</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the feed water valve to feed seawater to the evaporator. Adjust the feed water pressure. Normally marking is provided on the pressure gauge for desired feed water pressure.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > Open main engine jacket cooling water inlet and outlet to the evaporator gradually.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the air vent clock at the top of the evaporator to make sure the evaporator is filled with jacket cooling water. Air must be purged out if any.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Throttle the jacket cooling water by-pass valve</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Switch on the salinity alarm panel for measuring the purity of the freshwater produced.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > There will be a sight glass provided at the suction line for the distillate pump. Make sure condensed water is coming to the suction line. </span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Start the distillate pump and open discharge valve to lead generated water to specified storage tanks.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Checks during running</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Through the sight glass provided in the evaporator shell, observe flashing of water.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Also, check for the brine level inside. It should not be too high or too low.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Shell temperature must be around 50 deg cel.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Make sure the shell vacuum is more than 90% from the vacuum gauge.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check seawater inlet and outlet temperature to the condenser.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Ensure seawater pressure at air ejector inlet more than 3 bars.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check for distillate pump pressure and water flow meter.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check salinity of fresh water produced.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Check level and flow of dosing chemicals.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> > Check ampere of ejector pump and distillate pump motor.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Stopping</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Slowly open bypass valve for main engine jacket cooling water.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Ensure that main engine jacket cooling water temperature is within normal limits.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close jacket cooling water inlet and outlet valves for the freshwater generator respectively.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the feed water chemical dosing valve.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Stop the distillate pump and shut discharge valve.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Switch off the salinity meter.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the filling valve to the freshwater tanks.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Wait for evaporator shell temperature to drop below 50 deg cel.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close the feed water valve to the evaporator.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Stop ejector pump. Shut the fresh water generator overboard valve.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the vacuum breaker valve to make shell side pressure equal to atmospheric pressure.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Open the drain valve of the evaporator to drain all the seawater from the fresh water generator.</span></span></p>Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-87032149023012487872021-06-23T16:28:00.001+05:302021-06-23T16:28:39.608+05:30Overhauling of Centrifugal Pump And Checks<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"><b>Overhauling Procedure</b></span></div><div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;">> Put off breaker and remove fuse from motor starter box and issue isolation certificate<span><a name='more'></a></span></span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Close suction and discharge valve</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Remove suction and discharge pipe flange bolt & nut, coupling bolt of motor coupling</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Remove pump foundation bolts & take out pump from motor</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Remove impeller lock & nut & take out the impeller</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Remove mechanical seal</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Remove bearing cover from other side & take out shaft with ball bearing</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Renew mechanical seal and bearings if required.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Clean, replace and inspect all parts and assemble.</span></span></p><span style="font-family: verdana; font-size: medium;"><br /></span><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><b>Important Check points</b></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Impeller</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Wear ring</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Neck bush</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Ball bearing</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Shaft.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Mechanical seal</span></span></p><br />Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0tag:blogger.com,1999:blog-2987621616345501446.post-72480798781669738142021-06-23T16:24:00.002+05:302021-06-23T16:24:14.764+05:30What is Cavitation, Causes and Remedies<div style="text-align: left;"><span style="font-family: verdana; font-size: medium;"> <span style="white-space: pre-wrap;"> </span></span></div><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> Cavitation can occur when the pump suction contains air or when the pump is running faster than the designed speed<span></span></span></span></p><a name='more'></a><p></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"> Cavitation is the formation and accumulation of bubbles around a pump impeller. This tends to form in liquids of any viscosity as they are being transported through and around a pump system. When each of these tiny bubbles collapses or bursts, it creates a high energy shock wave inside the liquid. These shock waves hit the impeller and other pump components which cause erosion over time.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Causes</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Air leakage to suction side</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Pressure in the suction side is less than the vapour pressure of that pumping liquid</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> High temperature</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Throttled suction valve</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Pump running faster than the designed</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Pump taking suction lower than designed</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">Indication</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Decreased Flow or Pressure</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Erratic Power Consumption</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Pitting</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Noise</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Vibration</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Decrease in the pump efficiency.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;"><br /></span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><b><span style="font-family: verdana; font-size: medium;">How to Prevent Cavitation</span></b></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Reduce motor speed (RPMs). Note: Slowing the pump down will reduce flow rate and head pressure.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Incorporate a booster pump into your pump system. This will take some of the stress off of your primary pump.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> If possible, reduce the temperature of your pump, liquid, and/or other components.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Increase liquid level around the suction area.</span></span></p><p dir="ltr" style="line-height: 1.38; margin-bottom: 0pt; margin-top: 0pt;"><span style="font-variant-east-asian: normal; font-variant-numeric: normal; vertical-align: baseline; white-space: pre-wrap;"><span style="font-family: verdana; font-size: medium;">> Always keep NPSHA greater than NPSHR</span></span></p><span style="font-family: verdana; font-size: medium;"><br /><br /></span><br />Bijoy Chandrasekharhttp://www.blogger.com/profile/15805228736169635339noreply@blogger.com0