Oil content at the outlet of screw air compressor

The oil content at the outlet of the screw air compressor is a key indicator to measure its performance and compressed air quality. The following is a detailed answer from the standard scope, influencing factors and control methods:

standard range of oil content at the outlet of 1. screw air compressor

according to industry standards and manufacturer's recommendations, the oil content of the oil injection screw air compressor outlet is usually required. Not more than 3ppm (I. e. 3 mg/m & sup3;). If it exceeds this standard, it is considered that the fuel consumption is too high, commonly known as "running oil" or "flying oil". Note the following details:

1. normal fluctuation range: A small amount of oil may remain in the gas tank or pipeline, which is normal. For example, occasional oil traces at the bottom of the gas storage tank, or traces of oil in the compressed air after the post-processing equipment, are not considered faults.
2. Fault judgment basis: If the oil content of the outlet air continuously exceeds 3ppm, or the performance of downstream equipment (such as pneumatic valves and drying towers) decreases due to oil content, the air compressor shall be checked for failure.

2. Key Factors Affecting the Export Oil Content of Screw Air Compressor

1. improper oil level management
   • oil level too high: The oil level exceeds 2/3 of the liquid level mirror during shutdown, and the oil level fluctuates during operation, causing the oil to be taken away by the airflow.
   • Excessive refueling: Especially when the variable frequency air compressor is running at low frequency, the oil level in the oil barrel is too high, which aggravates the phenomenon of oil running.
2. Oil-gas separator fault
   • oil aging or damage: After long-term use, the oil is saturated, or physical damage (such as cracks) leads to a decrease in separation efficiency.
   • Return line problem: Oil return pipe blockage, improper installation (such as not inserted to the bottom of the oil), check valve failure, will cause the oil can not return.
3. Abnormal operation parameters
   • exhaust pressure too low: Insufficient pressure will increase the flow rate of the oil-gas mixture and exceed the oil processing capacity.
   • Abnormal exhaust temperature: High temperature reduces the viscosity of the oil and affects the separation effect; low temperature may cause condensed water to precipitate and dilute the oil.
4. Oil Quality and Selection
   • inferior engine oil: Poor defoaming performance, easy to produce foam and enter the oil core.
   • Oil mixing: Mixing different grades of engine oil may cause deterioration or gumming, blocking the oil core.
5. Equipment load and type selection
   • long-term low-pressure operation: If the rated pressure of the air compressor is 8kg/c ㎡, but the actual use pressure is only 5kg/c ㎡, the flow rate of the oil and gas mixture is too fast.
   • overload use: The air consumption exceeds the rated exhaust volume of the air compressor, so that the exhaust pressure continues to be low.

3. Control Method of Oil Content at the Outlet of Screw Air Compressor

1. optimize operating parameters
   • oil level control: Check the oil level after stopping, make sure it is between 1/2 and 2/3 of the liquid level mirror.
   • Pressure regulation: Avoid long-term low-pressure operation, adjust the exhaust pressure through the pressure maintenance valve or close the small ball valve.
   • Temperature Management: Clean the cooler to ensure good heat dissipation; avoid excessive ambient temperature or excessive cooling water flow.
2. Strengthen maintenance
   • periodic replacement of consumables: Replace the oil and gas separator, oil and filter element according to the manufacturer's recommended cycle, and use original accessories.
   • Clean the Return Line: Check whether the oil return pipe is blocked and whether the check valve is stuck or reversed to ensure smooth oil return.
   • Inspection of oil circuit: Check the problem of condensate backflow in the pipeline to avoid the failure of the minimum pressure valve.
3. Improve oil quality
   • selection of special oil: Give priority to the special oil for screw air compressor with good defoaming performance and strong oxidation resistance.
   • Avoid mixing oil: When changing the oil, completely drain the old oil to prevent the mixing of different grades of oil.
4. Post-processing equipment upgrade
   • installing precision filters: Add a precision filter (such as 0.01μm grade) at the outlet of the air compressor to further reduce the oil content.
   • Use oil removal device: For example, activated carbon filters or catalytic oxidation degreasing equipment are suitable for scenarios that require extremely high compressed air quality.
5. Equipment selection and load matching
   • reasonable selection: Select the air compressor with appropriate displacement according to the air consumption to avoid long-term low pressure or overload operation.
   • Add air tank: Buffer through the air storage tank to reduce the fluctuation of compressed air flow rate and reduce the burden of oil treatment.

Summary

the oil content at the outlet of the screw air compressor should be controlled through standardized operation, regular maintenance and reasonable selection. Users should pay attention to the operating status of the equipment, regularly check the oil content of the outlet, and deal with abnormalities in time (such as high oil level, blockage of the oil return pipe, etc.) to ensure that the compressed air quality meets the requirements of downstream equipment. If the oil content continues to exceed the standard, it is recommended to contact the professional after-sales service team for comprehensive investigation and maintenance.