Abstract: A system for crushing and discharging a powder and granular material that has become caked in a storage tank has a device for supplying compressed air that is used to activate machines as well as to blow up and deliver crushed material, a drilling machine which has drilling rotary blades that rotate at the distal end of a casing to drill a guide hole in the caked material for discharging crushed material by applying impact and rotation to the rotary blades by means of compressed air, and a crusher which has crushing blades to cut the opening edge of the drilled guide hole and to crush the periphery of the guide hole. A guide hole for discharging crushed grain is drilled in the caked grain by applying impact and rotation to the rotary blades of the drilling machine by use of compressed air, and after the guide hole has been drilled, crushing is carried out with the crusher. Since not electricity but compressed air is employed, it is possible to eliminate the fear of a spark being generated.