Requirements for compressed air, oil-free and water-free

Comprehensive Analysis of "Oil-free and Water-free" Requirements for Compressed Air

1. Core Standards and Definitions

1. oil-free standard
   • international Standard (ISO 8573-1):
     • Class 0(Highest grade): Oil content <0.01 mg/m & sup3;, suitable for high-precision fields such as semiconductors and pharmaceuticals.
     • Medical/Food Industry oil content ≤ 0.1 mg/m & sup3;(as specified in Chinese Pharmacopoeia and European Pharmacopoeia).
     • Breathing equipment oil content ≤ 0.5 mg/m & sup3;(such as EN12021 standard).
   • Implementation mode: Avoid oil contamination by oil-free compressors (e. g. oil-free screw, centrifugal), or use rear-end oil removal filters (activated carbon, precision filter elements).
2. Anhydrous standard
   • dew point temperature:
     • level 1 Standard(GB/T 13277.1): dew point ≤-70 ℃, water vapor content ≤ 2.6 ppmv.
     • General Industrial Standards: Dew point ≤-40 ℃ (water vapor content ≤ 127 ppmv), applicable to most manufacturing scenarios.
   • Implementation mode: Reduce the moisture content by drying equipment (freezing, adsorption, membrane).

2. technology means of realization

1. oil-free compressor type and principle
   • oil-free screw compressor:
     • spiral rotor precision meshing, without lubricating oil seal, direct compressed air.
     • Advantages: low pollution, high reliability; application: medicine, electronics.
   • Centrifugal oil-free machine:
     • the high-speed impeller pressurizes the air by centrifugal force without mechanical contact.
     • Advantages: large flow, low maintenance; application: chemical industry, power generation.
   • water-lubricated oil-free machine:
     • replace the lubricating oil with water and compress the air through the screw.
     • Advantages: environmental protection, low cost; Application: food, textile.
2. Selection of drying equipment
   • freeze dryer:
     • principle: cooling compressed air to 2-5 ℃, condensing water after discharge.
     • Dew point: 2-10 ℃; energy consumption: low; applicable scenario: general industry.
   • adsorption dryer:
     • principle: Adsorbent (activated alumina/molecular sieve) adsorbs moisture, and the two towers are regenerated alternately.
     • Dew point:-40 ℃ to -70 ℃; energy consumption: medium; applicable scenario: high-precision manufacturing.
   • Membrane dryer:
     • principle: polymer membrane selective permeable, separation of moisture in compressed air.
     • Dew point: 10-20 ℃; advantage: no energy consumption, small size; applicable scenario: portable equipment.
3. multistage filtration system
   • pre-filter: Removal of large particles (≥ 5 μm) and liquid water.
   • Precision filter traps tiny particles (0.01 μm) and oil mist.
   • Activated carbon filter: Absorb residual oil vapor to ensure oil content <0.003 mg/m & sup3;.

3. Industry Application Scenarios

4. continuous compliance management

1. regular inspection:
   • use dew point meter and residual oil analyzer to detect the quality of compressed air, and the frequency is recommended to be once a quarter.
2. Maintenance:
   • replace the filter element (every 2000 hours), adsorbent (every 2 years), and check the tightness of the pipeline.
3. Energy efficiency optimization:
   • frequency conversion compressor and heat recovery system are selected to reduce energy consumption by 20%-30%.

5. Summary

the "oil-free and water-free" requirement for compressed air must be passed. Oil-free compressor + drying equipment + multi-stage filtration the combination of implementation, and need to be combined with industry-specific standards (e. g. pharmaceutical GMP, electronic IPC) for customized design. Regular inspection and maintenance is the key to ensure long-term stable operation, while energy efficiency optimization can reduce the cost of the whole life cycle.