GB724905A - Improvement in blowpipe medium-pressure gas-mixer - Google Patents

Abstract

724,905. Blowpipe burners. UNION CARBIDE & CARBON CORPORATION. Jan. 12, 1953 [Jan. 16, 1952], No. 818/53. Class 75 (1). In an oxy-fuel gas blowpipe mixer including an elongated. fuel gas passage 8 and an elongated annular coaxial oxygen passage 24 having radial oxygen metering ports 26 at its outlet end, the fuel gas passage comprises a fuel gas metering port 14 or a group of fuel gas metering ports in parallel arrangement, the fuel gas metering port or ports and the radial oxygen metering ports 26 communicate with a single mixing chamber 18 or'with a plurality of mixing chambers and have equal capacities at equal fuel, gas and oxygen pressures and the cross-sectional area of any one mixing chamber is greater than that of the adjacent portion 16 of the fuel gas passage and the crosssectional area of the single or plurality of mixing chambers is smaller than that of a mixed gas passage 28 leading from the mixing chamber. The adjacent portion 16 of the fuel gas passage 8 is disposed between and in axial' alignment with the metering port 14 and the mixing chamber 18 and its cross-sectional area is such that the fuel gas flows therethrough at a velocity equal to that of the mixture flowing through the mixing chamber, the velocity being between 100 and 500 feet per second, preferably 350 feet per second. The length of the oxygen annulus 24 is at least five times its inner diameter and its thickness is between .005 and .015 inch. Two to six radial oxygen metering ports 26 are provided and if the number of such ports is even they are arranged in diametrically opposed pairs. The fuel gas passage 8 and the mixing chamber 18 are formed in an elongated tubular member 10 fitting within a socket in a blowpipe body 22 or inside another tubular member and the oxygen annulus 24 is formed by co-operating walls of the assembled members. In another embodiment exemplifying a group of fuel gas metering ports and a plurality of mixing chambers the gas metering ports and the mixing chambers are formed in an insert fitting within an enlarged recess in the fuel gas passage and the fuel gas passage includes a gas distribution chamber adjacent the inlet ends of the gas metering ports.