Oil Carry Over in Air Compressors on Ships
Starting air lines on board ships may contain large amount of air along with fine droplets of oil mixed with it. These oil droplets are formed by carry over from air compressors. Any source of heat when supplied to this rich mixture could result in catastrophic starting air explosion. So it is important to maintain starting air compressors in good condition. Compressor performance, oil separator operation, inter cooler and after cooler efficiency, etc. to be monitored periodically. Also drain all air bottles regularly to get rid of most of the water and oil.
Reasons for Oil Carry Over in Air Compressors
- Choking oil drain holes in the scraper rings
- Worn out oil scraper ring
- Wrong fitting of oil scraper rings
- Worn out liner
- Choking of crankcase breather (it results in crankcase pressurization and eventually oil carry over
- Excessive cylinder lubrication in some types of compressors
How to Minimize it
- Replace worn out scraper rings
- Clear holes of scraper rings
- Fit scraper rings properly
- Clean and clear crankcase breather
- Adjust lubrication to the top of the cylinder