GB693719A - Improvements in or relating to flame spraying apparatus - Google Patents

Abstract

693,719. Spraying fusible material. WIESE, R. A. Feb. 17, 1951. No. 3915/51. Class 69(iii) A flame spraying system comprises a spraying tool fed with powdered material in a carrier gas, and with fuel gas and oxygen, and includes means on the tool for regulating flow thereof through the tool, the powdered material being entrained in the carrier gas at a pressure lower than that at the carrier gas source, and means in the reduced pressure line for regulating the volume of carrier gas and powdered material delivered to the tool. Fuel gas and oxygen are fed through needle valves 16, 18, Fig. 14, respectively, on a spray gun, and pass through tubes 49, 50 in the gun handle to a mixing chamber 52, Fig. 13, from which the gas mixture passes through a passage 54 and annular chamber 56 to a tube 75. The combustion gas then enters an annular chamber 82, Fig. 8, and is delivered to circumferentially spaced orifices 81 surrounding an axial tube 77. The latter is supplied from a tube 59, Fig. 13, with a mixture of processing or carrier gas e.g. nitrogen, carbon dioxide, carbon monoxide, and powder. Compressed air mixed with carrier gas in the required proportions is supplied to the gun through a needle valve 14, Fig. 14, and leads from an annular chamber 58, Fig. 13, and orifices 71, 74 to the space within the tube 44. The mixture then passes through passages 86, 90, Fig. 8, to circumferentially spaced openings 96. A further supply of the carrier gas is fed to the gun at 32 and passes through a flexible tube 62 and a chamber 64, which is in communication with the gun handle interior, and also with the carrier gas supply through the valve 14. A pivoted valve 66 controls the amount of gas leaving the tube 62. Carrier gas is led through two separate valve controlled lines to inlets 102, 103, Fig. 21, of a chamber 39 at the base of a powder container 5, Fig. 18, and the gas passes through groups of orifices 106, 107, the latter group of which is directed downwardly into the chamber. The powder and gas is discharged through a fitting 109 to the gun. The carrier gas is supplied at a small volume and at low pressure e.g. 0.5 cubic feet per minute maximum at 15 lbs. per square inch maximum. The gas from the openings 96 does not exceed 30 cubic feet per minute at 75 Ibs. per square inch.