Meo class 4

Bell mouth is given at the end of  Heat exchanger tubes. If sharp edges are given then flow is separated this means it is not uniformly ditributed and turbulence is formed in flow which subsequently result in head loss and turbulence in flow decreases in heat transfer capacity of fluid Bell mouth helps in increasing area at entry of fluid which means there is pressure drop and low turbulence result in uniform flow in tubes and  no fluid separation takes place also results in no loss of head . Uniform flow of fluid results in more heat transfer and less erosion of tube surface takes place.. Although the flow doesnt stay in state of uniform flow it goes in transient region inside the tubes but still have high heat transfer property than flow in turbulence region.  Bell mouth also helps in holding the tube in  end plates  and it is so formed to increase the area as well as to form a seal on the plate so that there is no mixing also and hold the tubes there. Be...

There are different methods to find the fuel pump timing is correct or not. 1. Hair line method or fuel pump markings In some engines there is a window on fuel pump and on pump body there are three marking and on the plunger there is also one marking . The marking on pump body shows the start of injection and other shows the end of injection the middle one shows the unit is at TDC when the plunger marking matches with the respective one (as i found on diahatsu engine). But on some fuel pump only two marking are there  For start and end of injection. After matching any one of the marking check with the markings on flywheel , both should be matched if yes then there is no alteration in timing        2. Flash light method.                                       In this method both the deflectors of fuel punps are removed and then a flash light is used from one...

It is very important to knw the top dead centre of a unit to : 1. set the tappet clearence , 2. to check the fuel pump timing, 3. To check the misalignment of engine if new crankshaft  fitted or if slippage  of crankshaft happens. 4. To fit the timing gears also. HOW TO FIND OR CHECK THE TDC OF A UNIT. We can find the TDC by using following methods: 1. THROUGH THE FLYWHEEL MARKINGS.  It is the best method to find the position of particular unit at TDC and BDC as there are markings on flywheel for TDC andBDC  and a few degrees like 5,10,15 of that particular unit and so on or as IO ,EC and IS as inlet valve opens , exhaust valve closes. And injection starts. There is a arrow or a stationary marking  attached to fixd plate or frame anf pointed towards the flywheel markings , the pointer and markings on flywheel shows the unit number and its poaition at TDC. As if all the markings are gone then in some type of engines there is marking on crankweb of num...

There are lot of reasons for this 1. As in bunker tanks  no cow machine is used ,no tank washing is done regularly  so there is no chance of static charge accumulation , thatswhy there is no need of ig gas  , if washing is done on regular basis or before every bunker then there is need for ig gas system on every ship. 2. As per iso 8217:2010 standard the fuel oil to be used on ship must have  flash point not less than  60 degree so no ig is required. 3. Bunker tank size is not too large like cargo tanks so in case of rolling or pitching there is no chance of static charge and also  due to small size tanks there is not possible Chance of vapor emmision to sustain/ reach flamability range

Full form of SIPWA is sulzer integerated piston wear analysis. It is the system developed by sulzer to determine the continously average radial wear of the top piston ring. The top piston ring is called SIPWA ring fitted in top groove , and one sensor fitted on liner can be seen through inspection hole on pod level , it also consist of one angle decoder on cranlshaft whole systen is connected to electronic unit called solis state electronic unit, one recorder to record the reading one for every 4 unit , and one printer to print the result. Diagram of SIPWA is shown as.

For cleaning fresh water generator we have to drain sea water from the condenser and evaporator , also fill the drum with water and then add the appropriate chemical e.g saf acid and gamlen xd .fresh water generator can be cleaned by . SUBMERGED CLEANING. In this method pour the solution into the evaporator through sight hole until the upper tube plate is soaked , cleaning time varies with the scale thickness , when the solution becomes saturated change the chemical solution to new solution . In this method we have to clean the condenser separately by opening the side holes and using the wire brush and nylon brush to clean the tubes from inside. After cleaning drain the chemical solution and flush the evaporator why the seawater through the feed line. CIRCULATED CLEANING. In this method we have to use wilden pump to pump the solution into the fresh water generator there is a taping given before the condenser or open the flange to the inlet of condenser then connect the outlet of...