Combination dryer is made up of Refrigerated dryer and no heat regeneration dryer through proper pipeline connection. Among them, Refrigerated dryer can remove about 87% of water content in compressed air, while pressure dew point of outlet compressed air for regeneration dryer can achieve -40��. Comparing with no heat regeneration dryer and micro-heat regeneration dryer, operation of combination drying system is more reliable and has higher efficiency, saving greatly running cost