Why Do Compressed Air Systems Need Dryers?

In industrial compressed air systems, the formation of moisture is an unavoidable physical phenomenon. The negative effects it brings, however, can be prevented and controlled through sound, effective measures. As a core unit in compressed-air after treatment, the correct selection and configuration of a dryer directly affects the reliability of the entire pneumatic system, energy efficiency, and final product quality.

Moisture hazards to the system and production:

1. Equipment corrosion and reduced system reliability:
   Liquid water causes electrochemical corrosion in metal piping, air receivers, and pneumatic components. The resulting corrosion products form solid particulates that accelerate wear in cylinders, valves, and other precision parts, significantly shortening equipment life and increasing failure risk.

2. Process contamination risk:
   In industries with strict air-quality requirements, such as food and beverage, pharmaceutical manufacturing, coating, and electronics, moisture in compressed air can directly contaminate products, degrade quality, or even lead to full batch scrap, causing major economic losses.

3. Lower operating efficiency:
   Liquid water in pipelines increases pressure drop. To maintain end-use pressure, the air compressor must run at higher load, which raises energy consumption. In low ambient temperatures, condensate can freeze, blocking or damaging control elements and causing system shutdowns.

Selecting suitable drying equipment should be based on the application’s specific pressure dew point (PDP) requirement:

1. Refrigerated dryer
   Working principle: Uses a refrigeration circuit to cool compressed air to a low dew point (typically +3 °C to +10 °C), condensing and separating most water vapor.
   Applicability: Well suited for general industrial applications with moderate dew point requirements, such as general manufacturing, assembly, and material conveying, effectively preventing corrosion and basic moisture issues.

2. Desiccant dryer
   Working principle: Uses porous adsorbents, such as activated alumina or molecular sieves, to deeply adsorb water molecules in compressed air, achieving very low pressure dew points (down to −40 °C or even −70 °C).
   Applicability: Designed for applications with extremely strict air-quality requirements, including precision instruments, pharmaceutical production, food processing, and harsh industrial environments. It is an essential technical solution for ensuring high-quality production.

Shanghai Jiuzhou’s activated alumina and molecular sieve products are common desiccants used in dryers. A correctly engineered drying solution not only prevents moisture-induced equipment damage and production interruptions, it also improves system efficiency to save energy, creating long-term, stable economic value for the enterprise.