Adsorption dryer and method for operating adsorption dryer

An adsorption dryer comprising:

• a rotary adsorption rotor that is formed in a columnar shape, has a plurality of rotor flow paths penetrating in an axial direction, and includes an adsorption medium on a wall surface constituting each of the plurality of rotor flow paths;
• a casing that is formed in a cylindrical shape, rotatably supports the adsorption rotor concentrically accommodated, and has an inside partitioned about a central axis into a treatment zone, a regeneration zone, and a cooling zone, each extending in an axial direction;
• a treatment zone inlet flow path for supplying compressed air to the treatment zone;
• a treatment zone outlet flow path for supplying the compressed air having flowed through the rotor flow path of the treatment zone to a consumer side;
• a cooling zone inlet flow path for supplying to the cooling zone a cooling gas for cooling the adsorption rotor;
• a cooling zone outlet flow path for discharging the cooling gas having flowed through the rotor flow path in the cooling zone;
• a regeneration zone inlet flow path for supplying regeneration gas for regenerating the adsorption rotor to the regeneration zone;
• a regeneration zone outlet flow path for discharging the regeneration gas that has flowed through the rotor flow path in the regeneration zone from the casing;
• an outlet valve that is provided in the treatment zone outlet flow path and opens and closes the treatment zone outlet flow path;
• and
• a check valve that is provided in the treatment zone inlet flow path, and allows a flow of compressed air only in a direction toward the treatment zone via the treatment zone inlet flow path,
• wherein
• the cooling zone inlet flow path supplies a part of the compressed air having flowed through the rotor flow path of the treatment zone as the cooling gas,
• the regeneration zone inlet flow path has a one end portion branched from a portion of the treatment zone inlet flow path located closer to the treatment zone with respect to the check valve,
• the regeneration zone outlet flow path joins a portion of the treatment zone inlet flow path located closer to the treatment zone with respect to the one end portion of the regeneration zone inlet flow path,
• the cooling gas having flowed through the cooling zone joins the regeneration gas having flowed through the regeneration zone,
• an atmosphere release flow path is connected to the regeneration zone outlet flow path on a side closer to one end portion joining the treatment zone inlet flow path with respect to a position where the cooling gas joins the regeneration zone outlet flow path, and
• the atmosphere release flow path is provided in the middle thereof with an atmosphere release valve that has a distal end opened to the atmosphere, and that opens and closes the atmosphere release flow path.