Oil-injected screw air compressor is a commonly used compressed gas equipment in the industrial field, and its gas outlet oil content is the core index to measure equipment performance and gas quality. According to the industry technical specifications and practical application experience, the relevant issues are described as follows:
Oil Content Standard and Range of 1. Export
- Industry benchmark value
- The oil content of the compressed air at the outlet of the oil-injected screw air compressor is usually controlled 3 mg/m3 (3ppm) within. The numerical value is based on the oil and gas separation efficiency and the performance of the post-processing device under the normal operation state of the equipment.
- In special application scenarios, such as medicine, food, electronics and other industries that require extremely high gas cleanliness, the oil content needs to be further reduced 0.01 mg/m3 following to meet oil-free or very low oil content requirements.
- Excess risk warning
- When the oil content exceeds 3ppm, it may cause equipment failure (such as blockage of oil and gas separator), pollution of gas system (such as stuck pneumatic valve) and product quality risk (such as oil residue in food and drug production). It is necessary to timely investigate the causes and take measures.
Analysis of Influencing Factors of Oil Content in 2.
- Device Status Impact
- Oil-gas separator performance: As the core oil removal component, the accuracy, material and service life of the filter element directly affect the oil content. A poor quality filter element or a filter element that has not been replaced for a long time may result in a decrease in separation efficiency.
- Exhaust temperature control: Exhaust temperature is too high (such as more than 98 ℃) will reduce the viscosity of lubricating oil, weaken the oil and gas separation effect, increase the risk of gas with oil.
- Working condition of oil return system: Oil return pipe blockage, installation position deviation or oil return check valve failure may cause incomplete oil and gas separation, causing part of the oil to enter the compressed air.
- Maintenance Management Impact
- Filter element replacement cycle the filter element of the oil and gas separator needs to be replaced regularly (usually every 4000 hours or according to the differential pressure indication), and extended use will cause the filtration accuracy to decrease.
- Lubricating oil quality the use of inferior or deteriorated lubricating oil may increase the difficulty of oil volatilization and separation, so qualified oil should be selected according to the equipment requirements.
- Post-processing device configuration: If a precision filter or dryer is not configured, or the post-processing device fails, the oil content may not be reduced to the target value.
- Influence of operating conditions
- load rate fluctuation: Long-term low-load operation of the equipment may cause insufficient lubricating oil circulation and increase the oil content of the exhaust.
- Ambient temperature: High temperature environment may aggravate the oxidation of lubricating oil and affect the oil and gas separation effect.
3. Oil Content Control Optimization Measures
- Equipment selection and upgrading
- High-efficiency oil and gas separator and multi-layer glass fiber filter element are selected to improve the initial separation efficiency.
- For oil content sensitive scenarios, two-stage precision filters (such as primary filtration accuracy of 1 micron and precision filtration accuracy of 0.01 microns) can be configured to achieve deep oil removal.
- Operation and maintenance specification
- Regularly check and replace the filter element: Establish a filter element replacement cycle table and maintain it in time in combination with differential pressure monitoring data.
- Oil return system maintenance regularly clean the oil return pipeline to ensure that the oil return check valve functions normally to avoid oil accumulation.
- Exhaust temperature control: Optimize the cooling system (such as cleaning the fins of the oil cooler) to keep the exhaust temperature in a reasonable range (usually 75-95°C).
- Post-processing device strengthening
- Configure Dryer: Adopt refrigeration or adsorption dryer to reduce the dew point of compressed air and reduce the risk of oil condensation.
- Additional activated carbon filter: For very low oil content requirements, an activated carbon adsorption device can be added at the end of the post-processing chain to further remove residual oil vapor.
- Lubricant management
- Select high-quality lubricating oil matched with the equipment to avoid oxidation and deterioration of the oil.
- Regularly detect the physical and chemical indicators of lubricating oil (such as viscosity and acid value), and replace the deteriorated oil in time.
Oil Content Monitoring and Fault Diagnosis of 4.
- online monitoring technology
- The oil detector is used to monitor the oil content of compressed air in real time, and the data can be connected to the control system to realize overrun alarm.
- Combined with pressure and temperature sensors, the equipment health management system is constructed to warn potential failures in advance.
- Common Troubleshooting
- Sudden increase in oil content: Check whether the filter element of oil and gas separator is blocked and whether the oil return pipe is unblocked.
- Frequent failure of filter element assess the quality of lubricating oil and the operating conditions of the equipment, and check the unfavorable factors such as high temperature and high humidity.
- Post-processing device failure: Check the differential pressure of the precision filter and the adsorption capacity of the desiccant, and replace the failed parts in time.
Conclusion the oil content at the outlet of the oil-injected screw air compressor should be controlled through comprehensive measures such as equipment selection, operation and maintenance, and post-processing enhancement. Users should formulate targeted management strategies based on actual working conditions to ensure that the quality of compressed air meets production requirements, while reducing equipment failure rates and operating costs.