Selection Specification for Rotary Lobe Blower Lubricating Oil and Oil Deficiency Risk Warning

Rotary lobe blowers achieve gas compression through the rotation of eccentric rotors. Their lubrication system relies on pressure differential for automatic oil supply and must use No. 68 anti-wear hydraulic oil. This oil has moderate viscosity and can form a stable oil film in environments from -10°C to 80°C, reducing friction between the blades and the cylinder while preventing gas backflow. Using N220 gear oil (commonly used in Roots blowers) or other substitutes will cause oil film rupture, increased noise, and even seal failure.

Operating with oil deficiency has serious consequences. Rotary lobe blowers require 2-3 drops of lubricating oil per second. If the oil level falls below 1/3 of the oil tank, direct contact between the rotor and cylinder will generate high temperatures, leading to the following problems:

1. Equipment Damage: When friction heat exceeds 120°C, rotor blades may deform, and bearing life may be reduced by over 50%;

2. Abnormal Oil Consumption: Failure of the oil-gas separator can lead to oil leakage exceeding 0.5ml per hour. Long-term oil deficiency will cause oil seal aging;

3. Performance Degradation: Airflow fluctuation rate exceeds 10%, and aeration efficiency in wastewater treatment decreases by 30%.

Maintenance Specifications

Change the oil after the first 500 hours of operation, and then every 4000 hours thereafter, while simultaneously cleaning the air filter. If the oil temperature exceeds 85°C or the noise exceeds 75 dB, immediately stop the machine for inspection. Industry cases show that a wastewater treatment plant, due to untimely oil replenishment, experienced seized rotors in 3 blowers, with repair costs exceeding 20,000 CNY.

Conclusion

Rotary lobe blowers must use dedicated No. 68 anti-wear hydraulic oil. Operation with oil deficiency will directly lead to shortened equipment lifespan and a sharp increase in operating costs.

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