Air cannon, also known as air arch-breaking flow-aiding machine or dredger, eliminates the blocking by a sudden expansion shock wave, generated from the sprayed strong compressed gas with a speed of over i mach (sound velocity), directly blowing the blocked materials. It can resume material flow at one operation without causing the static friction of materials. Applying the aerodynamics, the equipment can convert compressed air into jet kinetic force with strong impact force and using a differential pressure device and automatic-controlled quick exhaust valve in it; so it is a kind of ideal clean and pollution-free block-cleaning soot -blowing equipment with low energy consumption. The equipment possesses advantages of simple structure strong impact force, safe, energy saving, easy operation with automatic control, and damage free for bunkers. Accroding to the customer's goods to decide