Oil content of oil injection screw air compressor

Oil Content Analysis of Oil Injection Screw Air Compressor: Standard, Influencing Factors and Optimization Scheme

1. Oil Content Standard and Industry Requirements

the oil content of the compressed air of the oil-injected screw air compressor usually needs to be controlled within 3ppm(3 mg/m & sup3;), but the specific criteria vary by application scenario:

• general Industrial Standards for example, the emission standard of pollutants for air compressor (GB/T 3785-2006) stipulates that the oil content is ≤ 5 mg/m & sup3;.
• Precision Manufacturing/Medical: Some scenarios require oil content <0.01 mg/m & sup3;(ISO 8573-1 CLASS 0 level).
• Special Industry oil-free compressed air may be required in food, medicine and other fields, and oil-free air compressor shall be used instead.

Core Influencing Factors of Excessive Oil Content in 2.

1. Filter performance degradation
   • filter element clogging: Oil and gas separator, primary/precision filter element is blocked or the quality is not up to standard, resulting in a decrease in oil removal efficiency.
   • Oil return pipe failure: The oil return pipe is blocked, offset or the check valve fails, so that the oil cannot flow back and is discharged with the compressed air.
2. Exhaust temperature too high
   • when the temperature is> 98 ℃, the viscosity of lubricating oil decreases, the separation of oil and gas is difficult, and the oil content increases significantly.
3. Lubricating oil quality problems
   • oil defoaming performance is poor, mixed with different brands of oil or too much oil, resulting in increased foam, affecting the separation effect.
4. Inadequate equipment maintenance
   • the oil and gas separator and filter element are not replaced on a scheduled basis, or the oil cooler is carbonized and coking, reducing the heat dissipation efficiency.

Test method for oil content of 3.

1. Simple Sampling Observation
   • use a transparent container for sampling. If there are scattered oil flowers on the water surface, it is normal, and the oil-water stratification exceeds the standard.
2. Professional instrument testing
   • the oil content is accurately measured by residual oil analyzer, laser particle counter and other equipment.

4. control and optimization scheme

1. Equipment selection and maintenance

• selection of original consumables: Match the filter element and lubricating oil to avoid oil leakage caused by inferior parts.
• Periodic replacement of parts:
  • oil and gas separator: replace every 4000 hours.
  • Primary/precision filter: synchronous replacement to ensure filtration accuracy (primary 1μm, precision 0.01 μm).
• Cleaning the oil cooler: Clean the air-cooled cooler fins every quarter to reduce the exhaust temperature.

2. Optimization of operating parameters

• control exhaust temperature: Ensure the temperature ≤ 98 ℃ by cleaning the cooler and replacing the super coolant.
• Adjust the injection quantity: Avoid excessive fuel injection (both waste and increase oil content), set the lubricating oil flow according to the equipment manual.

3. Post-processing upgrades

• add precision filtration: Add an activated carbon filter or a catalytic oxidation degreasing device before the drying tower to further reduce the oil content.
• efficient desiccant activated alumina desiccant is selected to improve the moisture adsorption capacity and reduce the generation of oil-water mixture.

4. Operation specification management

• avoid low load operation: Prevent condensate water from flowing backward due to long unloading time.
• Check the oil return system regularly confirm that the oil return pipe is unblocked, the check valve is well sealed, and the distance between the oil suction port and the bottom of the oil-gas separator is 3-5mm.

5. special scenario solutions

• ultra-low oil content demand(e. g. <0.01 mg/m & sup3;):
  • change air compressor without oil and water lubrication replace lubricating oil with water to fundamentally avoid oil pollution.
• Temporary emergency measures:
  • multi-stage filters (such as HEPA activated carbon) are added at the gas end, but the filter element needs to be replaced regularly.

6. Summary

the oil content of the oil injection screw air compressor should be controlled from standard understanding, equipment maintenance, operation optimization, post-processing upgrade four aspects of comprehensive policy. Regular testing, selection of original accessories, control of exhaust temperature is the key. If the oil content is extremely high, it is recommended to choose an oil-free air compressor or upgrade the post-processing system to ensure that the compressed air quality meets the requirements of harsh application scenarios.