According to the principle of absorption from the air compressor, the compressed air circulation drying and discharge capacity and regeneration ability of water in water (granular desiccant dryer has a strong adsorption air) to adjust the system pressure,. According to the principle of Absorption.it can cyclicly dry and ecple the humidty of the compressed air which comes from Air-compressor to adjust the system pressure, the grainy dryer has strong power to absorb the humidity and to regenerate.