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Showing posts from January, 2020

What is the purpose of the window installed in the housing of a fuel pump?

Through the window of the fuel pump housing, it is possible to see the movement of the sleeve up and down. The sleeve has one marking only. At the same time, the sides of the window also have one reference mark. When the reference mark on the sleeve starts moving upward, it indicates that the plunger is moving upward. When the mark on the upward moving sleeve coincides with the mark on the pump body, it indicates that the upward moving plunger has closed the suction port of the fuel pump. This is the beginning of the injection. This can be checked on the flywheel and, if required, can be adjusted and to allow the pump to be timed with the engine. The end of the injection will be dependent on the amount of fuel to be injected.

Why are quick closing valve fitted in a fuel system?

Quick closing valve are fitted in the fuel system so that in the event of a fire in the vicinity of these systems or break in these lines the system can be shut down rapidly and remotely, these valves are pneumatically operated. If by any means control air fails to reach the valve the system will fail. 

Engine Room Ventilation

In addition to providing sufficient air for combustion purposes in the main engine, the auxiliary diesel engines, the fuel-fired boiler, etc., the ventilation system should be designed to remove the radiation/convection heat from the main engine, auxiliary engines, boilers, and other components. A sufficient amount of air should be supplied and exhausted through suitably protected openings arranged in such a way that these openings can be used in all weather conditions, and care should be taken to ensure that no seawater can be drawn into the air intake. Furthermore, the ventilation air inlet should be placed at an appropriate distance from the exhaust gas funnel in order to avoid the suction of exhaust gas into the engine room. Air supply In the case of a low-speed two-stroke diesel engine installed in a spacious engine room, the capacity of the ventilation system should be such that the volume of air is at least 1.5 times the total air consumption of the main engine, auxiliary

Purpose of Charge Air Cooler?

The exhaust gas from the engine is utilized in the turbocharger for compressing fresh air to charge the engine with a positive pressure greater than ambient conditions. This compression causes the temperature of the air to increase, which thus cannot be fed directly into the engine as it is out of operating limits. Thus a cooler that brings the air temperature back to near ambient conditions is fitted on the engine. When the air is hot its density is less and thus the mass of air charged into the engine is less when compared to the mass when the air is cold. Thus the charge air cooler improves the charge air density and its temperature. The compressed charged air at the outlet of charged air cooler will have a reduced temperature of about 40 to 50 degrees celsius from a temperature of about 200 degrees celsius. This reduced temperature of the air will increase the density of the charge ait at low temperatures. Increased air density of the charge air will raise the scavenge effi

What are Emission Control Areas?

An application for designating a sea area as an Emission Control Area (ECA) must be approved by the Parties to Annex VI. ECAs may be designated for sulphur oxides (SOx) and particulate matter (PM), or nitrogen oxides (NOx), or all three types of emissions, subject to a proposal from an IMO member country. Annex VI originally set a limit of 1.50 percent sulphur for marine fuel oil used by ships sailing in designated Sulphur Emission Control Areas (SECAs).  The revised Annex VI lowered the sulphur limit in SECAs to 1.00 percent from July 2010 and to 0.10 percent as from 2015. The Baltic Sea was the first SECA to enter into force in 2006, followed by the North Sea (including the English Channel) in 2007. In March 2010, the IMO officially designated waters extending 200 nautical miles (370 kilometers) from the coast of the United States and Canada as the first “full” ECA, i.e. covering SOx, PM and NOx. The decision entered into force from August 2011 and the stricter sulphur limi