Abstract: A method and apparatus for effecting the continuous reliable supply of sodium bicarbonate particles to a blasting nozzle employing pressured air or water for conveying such particles into contact with a surface to be cleaned. The apparatus includes a hopper at atmospheric pressure and a removable orifice through which the abrasive particles are directed from the hopper to an open ended pipe. One end of the pipe is connected to a media conveying line and a venturi passage provided in a blast nozzle whereby a pressurized fluid passing through the venturi passage creates a suction force in the conveying line and the pipe such that atmospheric air and abrasive particles are drawn from the air pipe to the blast nozzle. The amount of air flow permitted through the pipe can be adjusted by a valve to control the vacuum within the conveying line and along with the particle feeding orifice controls the concentration of abrasive particles in the air stream directed to the nozzle.