Air drying system and method for drying compressed air using same

A method for drying compressed air, comprising:

• pressurizing wet air using a main compressor and supplying the compressed wet air to an inlet line;
• a dehumidification process in which the compressed wet air supplied from the inlet line is passing through a preset dehumidification tank between a pair of main air dryer dehumidification tanks in which a dehumidifying agent is filled, moisture of the wet air is absorbed in the dehumidifying agent to produce dry air, and the produced dry air is discharged to an outlet line;
• a heating process in which separate regeneration special dry air is supplied from a regeneration special dryer and heated by a heating unit installed in a heating line to heat and regenerate the dehumidifying agent that absorbs moisture included in another dehumidification tank that has performed the dehumidification process already while the dehumidification process is progressing, and heated regeneration special dry air is supplied to the another dehumidification tank and passes therethrough, and then, the dehumidifying agent that absorbs the moisture is heated and the moisture is detached;
• a cooling process of 1 to 3 hours such that hot air in a wet steam state reaches room temperature in a state in which power of the heating unit is shut off and driving is stopped after the heating process is finished;
• and
• a process of setting a first valve configured to transfer a path of the regeneration special dry air supplied from the regeneration special dryer to either one direction between a direction to the outlet line or a direction to the heating unit such that the regeneration special dry air supplied from the regeneration special dryer is transferred to the outlet line.