What is a turbocharger ?

Very basic.

Turbochargers can be found on all ships fitted with modern marine diesel engines. It is an equipment which reuses the exhaust gases in order to increase the overall efficiency of the engine by supercharging the air which is supplied to main engine . Basically, it is a device which energizes the engine.

It consists of two parts – Turbine and the blower / compressor.

The exhaust gas of the main engine flow in / out of the turbine. This turbine while rotating converts heat energy into rotational energy. The rotational energy is connected to the compressor which draws air and compresses and supply to the main engine air system.

What happens to turbocharger at reduced speed? What are auxiliary blowers?

• At reduced speeds it supplies inadequate air quantity to ME scavenge necessary for efficient combustion. So the engineers will start auxiliary blowers to assist the turbochargers.
• They are electrical driven blowers provided to assist the turbocharger at low loads ie.  when turbocharger is not working efficiently due low engine speeds (less exhaust gases). They normally cut-in / cut out automatically.

What is soot blowing?

During day to day running the turbine and compressor tends to get oil mist, dust, soot, fuel derived ashes, metallic ashes deposits on the them. These deposits can greatly effect the efficiency of the turbocharger. Soot blowing is carried out to keep the turbocharger clean.

How is soot blowing done?

• Dry Cleaning – A container is filled with cleaning material (nutshells / activated carbon / or small grains (in emergency). It is then blown thru with compressed air into the turbine casing.  It normally carried out everyday.
• Wet Cleaning – It is normally carried out weekly or time permitting. The ME speed has to be reduced for this type of cleaning tp reduce thermal shock.

 

Ok friends, please do let me know if you have any other query. The idea is to make the junior deck officers in a very basic and simple manner.