Does the air compressor have oil?

As the core air source equipment in the industrial field, the lubrication mode of air compressor directly affects the quality of compressed air and the operating characteristics of the equipment. The following from the technical classification, working principle and selection of three aspects of the proposed description:

classification of 1. Technology and Lubrication Characteristics

1. oil-lubricated compressor
   • working principle: Inject lubricating oil into the compression cavity to form an oil film to achieve lubrication, sealing and cooling between the rotors. A typical example is an oil-injected screw air compressor.
   • air characteristics: The oil content of compressed air is usually 3-5ppm (mg/m3), and a precision filter is required to reach the oil-free standard.
   • Applicable Scenarios: Suitable for general industrial gas, such as pneumatic tools, tire inflation and other occasions that do not require high air quality.
2. Oil-free compressor
   • technical route:
     • dry oil-free: Use Teflon coating or ceramic bearings to achieve oil-free compression through the self-lubricating characteristics of the material, such as centrifugal air compressors.
     • water lubricated oil free: Replace lubricating oil with pure water, and realize lubrication and sealing through water film, such as single screw water lubricated air compressor.
   • air characteristicsthe oil content of compressed air is 0ppm, which can be directly used in food, medicine, electronics and other fields with high requirements for cleanliness.
   • Technical advantages: Completely avoid the risk of oil pollution, while reducing fire hazards.
3. semi-oil-free technology
   • composite Scheme: The oil injection screw machine and multi-stage filtration system (such as catalytic oxidation filter and activated carbon adsorber) are adopted to reduce the oil content to below 0.01ppm.
   • Economy: The initial investment in the equipment is low, but the cost of filter replacement is borne later.

Influence of 2. Lubrication Methods on Equipment

decision-making recommendations for 3. selection

1. gas Quality Priority Scenario
   • directly select water-lubricated oil-free compressor to ensure that the compressed air is 100 oil-free. Typical applications include:
     • pharmaceutical industry: pneumatic control in the pharmaceutical production process;
     • food industry: food packaging and modified atmosphere preservation;
     • electronics industry: chip manufacturing and precision cleaning.
2. Cost Control Priority Scenarios
   • oil-injected screw machine + post-treatment scheme can be selected to realize oil-free air through three-stage filtration (coarse effect, fine effect and activated carbon). Note:
     • the filter needs to be replaced every 2000 hours, and the annual maintenance cost increases by about 15%;
     • oil heating device shall be configured in low temperature environment to prevent emulsification.
3. Special condition adaptation
   • explosion-proof area: give priority to oil-free design to eliminate the potential safety hazard caused by the accumulation of lubricating oil;
   • high altitude areas: oil-free compressors are more adaptable due to the risk of oil-free emulsification.

4. technology development trend
as the industry’s requirements for air cleanliness increase, the market share of oil-free air compressors is growing at a rate of 8% per year. Among them, water lubrication technology has become the mainstream solution to replace traditional oil models because of its environmental protection and economy. For example, a certain type of water-lubricated compressor can achieve 12% energy efficiency improvement and 5dB noise reduction (A).

Whether the air compressor contains oil depends on its core technical route. Enterprises should comprehensively evaluate the gas quality requirements, life cycle cost and process suitability in the selection, and if necessary, entrust professional institutions to carry out air quality testing in order to formulate the optimal gas supply scheme.