Longer Life of Air Compressors, Lower Maintenance
CHALLENGE
The air compressors for Hapag Lloyds vessels had reduced operating time, and great need for maintenance and parts. High air moisture in humid climates generated water condensates in air compressors when air was cooling between compression stages and after compression.
This moisture mixes with lubricating oil affecting
lubricity, increasing friction, and. As a consequence, the
oil oxidize and carbonize faster, machine parts start
wearing out increasing the costs of spare parts,
maintenance, and downtime.
For stopping this process, the company evaluated Rewitec Surface Treatment. Three Sauer WP air compressors (3-stage air-cooled medium-pressure 70 bar) were coated with Rewitec. The treatment was added to the 15 liters of oil while in operation. The 3 compressors were kept in operation for 4 to 6 hours in order for the coating process to start.
OUTCOME
The engineering crew noticed that- In the 3 months after the treatment, there was no maintenance required compared to before the treatment. No shutdown was needed.
- The electric motors consumed less energy when the compressor idled.
- Oil temperature was lower and did not increase over time
- Shorter time needed for the compressors to achieve nominal pressure.
- The valves did not carbonize as before, extending 4 times its maintenance.
RESULTS
Since September 2005, neither spare parts were needed nor are repairs done. Flap valves maintenance was extended from 6 months to 2 years. The compressors are operating with the scheduled oil changes.
The company later treated most of the other compressors with Rewitec.
Total savings in maintenance amounted to approximately $10,000 per compressor per year.
REFERENCE
Hapag Lloyd Shipping, Hamburg, Germany