Water/abrasive propulsion chamber

摘要

A propulsion apparatus adapted for use in a liquid propelled abrasive cleaning system is disclosed in which high pressure water is injected coaxially in a bore of a housing to which a flow of air and abrasive is introduced. The high pressure water is introduced into the bore via a water injection member fixed in the bore. The water injection member has a cross-sectional area which is small compared to that of the bore. A first embodiment of the invention includes a wing shaped water injection member which extends diagonally across the bore of the housing. A second embodiment of the invention includes a sloping leading edge with low axle oblique surfaces serving to deflect abrasive particles around the member and back into a high velocity air/abrasive longitudinal flow. The leading edge of the water injection member is small compared to the widest part of the member in the bore thereby creating an air-foil effect for the air/abrasive mixture flow as it passes the injection member in the bore. The streamlined shape of the injection member decreases the erosion of it from the flow of air and sand entering the bore and creates coaxial acceleration of the abrasive particles downstream of the water injection member. Downstream of the water injection member, the air/abrasive flow is propelled by the high pressure water at great velocity via the outlet of the bore.