Abrasive media blasting method and apparatus

Abstract

An improved media blasting system that separates the fluid velocity development, the introduction of media and the acceleration of media from each other. The preferred arrangement has a supersonic nozzle that produces supersonic velocity air discharged into a coupled acceleration chamber. No shot travels within the supersonic nozzle, so no wear of the supersonic nozzle interior occurs, thus making the nozzle shorter, of plain metal alloys, less expensive to manufacture and lasting indefinitely. The shot is separately introduced into the acceleration chamber thus avoiding it's otherwise limitation to the air mass flow rate in the air supply hose or pipe. Thus the average velocity used to transfer momentum to the shot is much higher than the lower average velocity currently available within other blasting nozzles, which occurs from throat to exit. Further, the nozzle design parameters are selected to match the higher maximum power output of a selected air compressor and are not constrained by nozzle wear factors requiring frequent replacement of the nozzle for reasons of nozzle wear.