Pressure blast apparatus

摘要

1,070,867. Blasting. PANGBORN CORPORATION. Feb. 8, 1965 [Feb. 11, 1964], No. 5457/65. Heading B3D. Pressure blast apparatus comprises a mixing chamber the interior of which conforms to a Venturi confuguration, abrasive particles stored under pressure in a hopper passing into the mixing chamber at the throat. Gas is supplied through conduit 15 to the inlet of the mixing chamber 5 and through branch conduit 17 to the hopper 1. Abrasive from the hopper 1 passes through discharge opening 27 and metering orifice 28 into the throat of the mixing chamber 5. The outlet of the mixing chamber 5 is connected by a conduit 11 to blast-sealing, work clamping means 13. This comprises a rigid housing 31 in which a diaphragm 37 is clamped by members 39, 41. The member 39 is attached to the conduit 11. The member 41 has an opening to receive the end of a long, small diameter tube 49 the interior of which is to be blasted; the tube is clamped by admitting gas pressure through conduit 43. This is done manually or automatically. The means 13 may be located some distance from the mixing chamber 5, but is preferably close to it; the mixing chamber 5 and means 5 may be in a single unitary housing. The abrasive may be fused aluminium oxide or similar material, 100 mesh, or finer; gas pressures of 380 p.s.i.g. or 500 p.s.i.g. may be used. The hopper 1 has a filling plug 25; alternatively, automatic means for replenishing the hopper may be provided, manual or automatic stirring means may be provided. The metering orifice 28 may contain a manual or automatic regulating device. The conduits 15, 17 may be connected to separate sources of gas pressure. The conduit 15 may contain a gauze and a regulating valve operated manually or automatically; it may actuate the regulating device in the metering orifice 28 or be actuated thereby. The hopper 1 and mixing chamber 5 may be bolted together or formed as a unitary casting. Alternatively the hopper 1 may be located some distance from the mixing chamber 5, and connected thereto by a conduit. The mixing chamber 5 may be used in multiples, e.g. 5-10 with a common gas supply line. The discharge ends of the tubes being blasted are inserted in a hood with an abrasive reclaiming hopper below and a connection to a dust collector. The apparatus may be portable, having a tripod secured to the hopper 1, or stationary.