High level oxygen during IGG operation
When a vessel reports problems with a high oxygen level during their IGG operation, Ravebo’s service engineers attended the vessel and carried out the following checks on the IGG system.
- Checked/calibrated the I/P converter for the Fuel oil control valve, it was recorded that this unit was out of range and was replaced with a new unit.
- Continued further checking and noticed that the positioner of the capacity valve (EP0062) wasn’t working so replaced with a new one. Same problem was found with the positioner of the IG to vent valve, so this was also replaced.
- After opening the fuel control valve (0230), noted that the membrane had to be replaced. The above trouble is primarily occurring due to oil content in the air, which is generated from the air compressor. Checked the zero point of the IG deck pressure indicator which was within tolerances.
- All IG pressure indicators were reading within permitted tolerances after small zero corrections on each meter.
- Checked all other parameters and adjusted the height of the burner to 50mm between the flanges.
Conclusion was that the capacity valve was fully open and therefore the air moved through the IGG too quickly to burn off the oxygen.
This was the reason that the oxygen content was to high as this has to be around 3%. After all the above procedures were carried out the Oxygen level was at a normal level.