47.Turbocharger washing

What is the main purpose of turbocharger water washing ?

• To ensure efficient functioning of turbocharger.
• To protect the compressor and turbine from contamination (Deposits).

How will you carry out turbocharger turbine and blower side water washing ?

Blower side water washing

1. It can be done when M/E on full load.
2. Fill up the warm fresh water to hopper and closed the cover.
3. Open the valve and water will flow into the blower casing and mechanically attack the blower blades and clean the deposit.
4. Close the valve, open the cover and check the cleaning water must be empty.

Turbine side water washing procedure

1. Turbine side water washing can be made with hot fresh water.
2. Inform to the bridge
3. Reduce the M/E rpm to recommended speed and hence turbocharger rpm.
4. Check the water washing injection nozzle if fitted. (directly aim to the exhaust grips before entering to the turbocharger)
5. Open turbocharger drain valve.
6. Open the water supply about 1 bar to turbine side.
7. Water washing must be made until the clean water comes out.
8. Close the water supply and remove the nozzle.
9. Exhaust side drain can be closed after all water is drained out and dried.
10. Inform to the bridge and increase the M/E rpm gradually to sea speed.
11. The turbine side water washing is usually at departure after manoeuvring time.
12. For usual practice cleaning is done at every 500 hr, running hour depending on the cleanliness of the turbocharger .

Grit Washing or Dry Cleaning of Turbocharger

1. Turbine side cleaning is superseded by walnut shell, with grain size of 12 to 34 mesh 
2. No speed reduction required and cleaning can be done at full speed, once every day
3. 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
4. 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
5. Turbine casing drain kept open during cleaning time (about 2 minutes only)