Patent attributes
A cleaning and releasing device has a hand valve provided on a flow passage of a pressurized liquid in the vicinity of an injection nozzle, a switching valve 5 provided in a proper position on the flow passage of a pressurized gas, flow detecting means provided in a proper position on the flow passage of the pressurized liquid, and a controller for controlling the switching operation of the switching valve based on a result of detection transmitted from the flow detecting means, and controls the switching valve to supply and stop the pressurized gas depending on the presence of a flow of the liquid generated by the switching operation of the hand valve. The supply and stop of a powder and granular material may be controlled based on the result of detection transmitted from the flow detecting means.