A circulation cleaning device includes a base unit, a carrier unit juxtaposed with the base unit in a conveying direction, a cleaning unit juxtaposed with the carrier unit in the conveying direction, a direction-changing unit juxtaposed with the cleaning device in the conveying direction, and a drying unit disposed between the carrier unit and the direction-changing unit in the conveying direction and juxtaposed with the cleaning device in a transverse direction. A control method of the circulation cleaning device is provided to clean and dry a boat in circulation by moving the boat sequentially through the base unit, the carrier unit, the cleaning unit, the direction-changing unit, the drying unit and back to the base unit.

The present disclosure discloses an intake duct structure for a blow dryer, which includes a housing. The housing defines a housing intake port, and a blow dryer motor is arranged within the housing. It also includes an intake duct, one end of which is the duct intake port. The duct intake port is offset from the housing intake port, and the intake duct extends along the outer wall of the housing from the duct intake port to the housing intake port, such that the other end of the intake duct communicates with the housing intake port. The present disclosure also discloses a blow dryer. Through the above structural arrangement, the intake duct structure of the blow dryer is extended. The noise emitted by the blow dryer motor must pass through the housing intake port, the intake duct, and the duct intake port before propagating outward.