Dehumidification drying system for synthetic resin molding material

A dehumidification drying system comprising:

• a drying hopper for storing a synthetic resin molding material inside;
• a dehumidifier for producing dry air to be supplied to the drying hopper to dry the synthetic resin molding material;
• a dry-air flow path for transporting the dry air from the dehumidifier to the drying hopper;
• a humidified-air flow path for transporting humidified air discharged from the drying hopper after being used to dry the synthetic resin molding material to the dehumidifier;
• and
• a cooler for cooling the humidified air, the cooler being provided in the humidified-air flow path;
• wherein
• the dehumidifier contains an adsorbent and is configured to produce the dry air by allowing the adsorbent to remove moisture contained in the humidified air by adsorption, and to regenerate the adsorbent by allowing regenerating gas to remove the moisture adsorbed by the adsorbent by desorption,
• wherein
• the cooler is configured to cool the humidified air by heat exchange with outside air,
• wherein
• the dehumidification drying system further comprises:
• a regenerating-gas flow path for transporting, as the regenerating gas, the outside air having an elevated temperature as a result of heat exchange with the humidified air discharged from the cooler to the dehumidifier;
• a first heater for heating the outside air discharged from the cooler, the first heater being provided in the regenerating-gas flow path;
• a used-regenerating-gas flow path for transporting used regenerating gas discharged from the dehumidifier after being used to regenerate the adsorbent in the dehumidifier to the outside of the system;
• and
• a preheater provided upstream of the first heater in the regenerating-gas flow path, and
• wherein
• the preheater is configured to preheat the outside air discharged from the cooler by heat exchange with the used regenerating gas.