Desiccant Compressed Air Dryer two types ---heatless purge and externally heated purge 1). Heatless purge desiccant air dryer Inlet temperature: 0~45 Celsius degree Inlet oil content: less than 0.01ppm Working pressure: 0.6~1.0Mpa Dew point: -20~-70 Celsius degree Purge air: less than 12% Desiccant: Activated alumina & molecular sieve Purge mode: Heatless purge Working method: Continuing alternation between two towers Working periods: T=10~20min. Control mode: Micron computer auto controlling Installation mode: Indoor, non-basement 2). Externally heated purge air dryer Inlet temperature: 0~45 Celsius degree Working pressure: 0.6~1.0Mpa Dew point: -40~-70 Celsius degree Purge air: less than 4~6% Desiccant: Activated alumina & molecular sieve Purge mode: Externally heated purge Working method: Continuing alternation between two towers Working periods: T=120~140min. Control mode: Micron computer auto controlling Installation mode: Indoor, non-basement