How much oil is contained in the compressed gas of the oil-injected screw air compressor

The oil content of the compressed gas of the oil-injected screw air compressor depends on the equipment performance, maintenance status and the configuration of the end purification device. The following is an authoritative interpretation based on industry norms and technical parameters:

relationship between 1. core working principle and oil content

1. oil injection lubrication mechanism
   the oil-injected screw air compressor is realized by injecting lubricating oil into the compression chamber:
   • lubrication: Reduce friction between yin and yang rotor and bearing
   • cooling: Absorb the heat of compression (can take away 60-70% of the heat)
   • seal: Fill the rotor gap to improve compression efficiency
2. composition of oil separation system
   compressed mixture of oil and gas through:
   • primary separation: Preliminary separation of large oil droplets by rotor centrifugal force (efficiency about 70-80%)
   • fine separation: Using multi-layer glass fiber filter element (accuracy 1-3μm), the separation efficiency can reach 99.99
   • final filtration: Some models are equipped with post-filter (accuracy 0.01 μm) to achieve oil content <0.01 mg/m & sup3;

typical oil content range of 2.

1. Unpurified state
   • the original oil content of the exhaust port: 30-100 mg/m & sup3;(depending on the state of the oil core)
   • when the oil core pressure difference is> 0.1MPa, the oil content may surge to 200 mg/m & sup3; Above
2. standard after purification
   • general Configuration: After treatment with precision filter, the oil content can be reduced to 0.1-1 mg/m & sup3;
   • high purity requirements: Add activated carbon filter or membrane separation device, oil content <0.003 mg/m & sup3;(close to oil-free level)

3. Key Factors Affecting Oil Content

1. equipment running status
   • oil core life: new filter separation efficiency> 99.9, after 2000 hours of use to 95%
   • fuel injection volume control: Excessive fuel injection volume (>1.2L/m & sup3;) will cause oil droplets to be refined and increase the difficulty of separation
   • system pressure: pressure fluctuation> ± 0.05MPa, the separation efficiency decreased by 10-15%
2. maintenance Impact
   • filter element replacement cycle: It is recommended to replace it every 2000 hours. Overdue use will cause the oil content to increase by 3-5 times.
   • Oil quality: The use of inferior oil will cause carbon deposits to block the filter element and reduce the separation efficiency
   • pipeline cleanliness: the particles produced by pipeline corrosion will damage the oil film and increase the carrying amount of oil droplets.

4. industry application standards

1. general Industrial Scenarios
   • allowable oil content: ≤ 5 mg/m & sup3;(equivalent to ISO 8573-1 Class 2 standard)
   • typical applications: Power tools, general pneumatic control
2. precision manufacturing field
   • required oil content: ≤ 0.1 mg/m & sup3;(ISO 8573-1 Class 1)
   • typical applications: precision spraying, food packaging, pharmaceutical production
3. special Process Requirements
   • semiconductor manufacturing: oil-free standard (oil content <0.003 mg/m & sup3;)
   • breathing gas: need to be equipped with catalytic oxidation device to convert oil vapor into CO₂ and H₂ O

5. oil content control recommendations

1. key points of equipment selection
   • select the oil core with differential pressure sensor to monitor the separation efficiency in real time
   • configuration of two-stage filtration system (precision filter + activated carbon filter)
   • frequency conversion model is preferred to stabilize pressure fluctuation
2. operation and maintenance specification
   • daily discharge of oil and gas cylinder condensate to avoid emulsification of oil-water mixture
   • quarterly detection of exhaust gas oil content (infrared spectroscopy is recommended)
   • clean the oil system during the annual overhaul to prevent carbon deposition and blockage
3. emergency treatment measures
   • when the oil content exceeds the standard, switch the standby filter immediately.
   • Short-term emergency: add a temporary filter in the pipeline (accuracy 0.1 μm)
   • long-term plan: upgrade to a two-stage compression interstage cooling system to reduce oil droplet evaporation

the exhaust oil content of oil-injected screw air compressor can be controlled within a reasonable range through equipment selection, system configuration and standard maintenance. For oil-sensitive application scenarios, it is recommended to configure the end purification device and establish a regular detection mechanism to ensure that the compressed air quality meets the process requirements.