What are the air purity and humidity requirements of an air compressor?

The requirements for air purity and humidity of air compressors vary according to application scenarios and need to be determined based on specific industry needs and international/domestic standards. The following is a detailed analysis:

1. International standard (ISO 8573-1)

The ISO 8573-1 standard formulated by the International Organization for Standardization (ISO) clearly classifies the purity (oil content, particulate matter) and humidity (dew point) of compressed air. It is a general and authoritative international standard.

1. purity classification：
   • solid particles: It is divided into grades 0-9. The lower the level, the lower the particle concentration. For example, level 0 requires ≤0.1μm particles ≤200 particles/m³.
   • Humidity (dew point): It is divided into levels 0-9. The lower the level, the lower the dew point temperature (that is, the drier the air). For example, level 0 requires a dew point of ≤-70 ° C.
   • oil content: It is divided into grades 0-4. The lower the level, the less oil content. For example, Level 0 requires a total oil amount of ≤0.01mg/m³.
2. detection method：
   • particulate matter: Measure using a laser particle counter.
   • oil content: Use spectroscopic analysis method or color reaction tube (detection limit can reach 0.1mg/m³).
   • dew point: Measured by dew point meter or capacitance hygrometer.

2. China Standard (GB/T 13277)

China’s national standard GB/T 13277-2023 “Compressed Air Part 1: Purification Levels of Pollutants” equally adopts the ISO 8573-1 standard, which stipulates the purification levels of particulate matter, water and oil in compressed air, and supplements relevant testing methods.

1. quality level：
   • It is divided into four levels, with the first level being the highest (such as oil content ≤0.01mg/m³) and the fourth level being the lowest. Suitable for general industrial purposes, special industries need to refer to other standards.
2. humidity measurement：
   • GB/T 13277.3 specifies dew point method, capacitance method, chemical adsorption method, etc., and requires measurement error ≤±2%.

Third, different industries on air compressor air purity and humidity requirements

1. Semiconductor and pharmaceutical industry：
   • purity: ISO Class 0 or 1 is usually required, that is, oil content ≤0.01mg/m³ and particulate matter ≤0.1μm.
   • humidity: Dew point needs to be ≤-40 ° C to-70 ° C to meet high-precision process requirements.
   • microbial: Sterile filtration is required, and the microbial content is ≤1 CFU/m³.
2. food and beverage industry：
   • purity: ISO Class 2 or 3 is required, that is, oil content ≤0.1mg/m³ and particulate matter ≤1μm.
   • humidity: The dew point must be ≤-20 ° C to-40 ° C to prevent moisture from contaminating the product.
3. General industrial applications：
   • purity: ISO Class 4 or lower is acceptable, i.e. oil content ≤5mg/m³ and particulate matter ≤5μm.
   • humidity: Dew point needs to be ≤-20 ° C to meet general power needs.

4. Control technology for air purity and humidity of air compressor

1. post-processing apparatus：
   • Leng gan machine: Refrigeration technology is used to cool the compressed air to above the dew point to remove most of the moisture, and the dew point can reach about 3°C.
   • Dry dryer (dryer): Using adsorbent to adsorb moisture can provide extremely low dew point temperatures (below-40 ° C) to meet high-precision process requirements.
   • precision filter: Filters particulate matter and oil in compressed air, with a filtration accuracy of 0.01μm.
2. monitoring and maintenance：
   • regular testing: Drain condensed water from air storage tanks daily and conduct third-party certification testing quarterly.
   • real-time monitoring: Use online dew point meter and oil vapor detector to monitor compressed air quality in real time.

V. Implementation recommendations

1. Select criteria according to application scenario：
   • Semiconductor, pharmaceutical and other industries need to choose ISO Class 0 or 1 standards.
   • Food and beverage industries can choose ISO Class 2 or 3 standards.
   • ISO Class 4 or lower is available for general industrial applications.
2. Configure appropriate post-processing equipment：
   • Choose a combination of cold dryers, dry cleaners and precision filters based on the desired dew point temperature and purity level.
3. Establish regular inspection and maintenance mechanisms：
   • Ensure stable compressed air quality and extend equipment service life.

Through the above measures, the air purity and humidity of the air compressor can be effectively controlled to meet the needs of different industries.