The Cleaning of the Turbine side and blower side is necessary at regular intervals to remove carbon, soot, and other exhaust deposits. There are two methods to clean the turbine and compressor side of a turbocharger while running.
Turbine Side Washing
Turbine side cleaning can be carried out both water and Dry washing method
Water Washing
> Inform to the bridge
> Reduced until the temperature of the exhaust inlet falls below 420 °C(aprox)
> Check the water washing injection nozzle.
> Open turbocharger drain valve.
> Open the water supply about 1.5 bar to the turbine side.
> Water washing must be made until the clean water comes out.
> Close the water supply and remove the nozzle.
> Exhaust side drain can be closed after all water is drained out and dried.
> Run the M/E for 10min on same load
> Inform to the bridge and increase the M/E rpm gradually to sea speed.
> For usual practice cleaning is done at every 500 hr, running hour depending on the cleanliness of the turbocharger
Disadvantage of Water washing
> Engine speed has to reduce.
> Thermal stress and corrosion usually occurred because of ingress water .
> More time required to complete the operation
> Very fine hard deposits and residues cannot be removed easily with water washing.
Dry Washing
> The engine speed is not reduced as there is no risk of thermal stresses in dry washing.
> Dry washing is carried out by walnut shell, with grain size of 12 to 34 mesh
> Compressed air of (3 -5 bar) is used to help the grains strike the deposited Turbine Blades and Nozzles, giving effective cleaning of hard particles
> Air supply pipe is fitted to solid grain container, and grains are injected into exhaust system by air pressure, at the same point (as in water washing ) just after exhaust grids
> Turbine casing drain kept open during cleaning time (about 2 minutes only)
> Dry washing should be carried out every day while M/E running
Advantages
> Not required to reduce engine rpm, thus not affect the vessel performance.
> No use of water, so no corrosion and thermal stress.
> Cleaning time is short and easy to carry out.
> Effectively remove combustion residues and hard particles.
Compressor side Washing
> Compressor/blower side washing can be done when the M/E on full load.
> Fill up the warm fresh water to hopper and close the cover.
> Open the valve and water will flow into the blower casing and mechanically attack the blower blades and clean the deposit.
> Close the valve, open the cover and check the cleaning water must be empty.
You Can Answer following questions
> What is the importance of turbocharger washing
> At what temperature turbocharger washing carried out
> Turbocharger washing is carried out at what load/speed?
> Procedure for turbocharger washing