GB927257A - Oxy-fuel gas burner for thermally treating metal - Google Patents

Abstract

927,257. Oxy-fuel gas torches. UNION CARBIDE CORPORATION. July 4, 1961, No. 24046/61. Class 75 (1). A burner for heat treating metal surfaces with flames produced by the combustion of gas mixtures flowing at supersonic velocities comprises a passage 16 supplied with combustible gas mixture and a plurality of discharge passages 30 of increasing cross-section, each discharge passage comprising a metering orifice 34 providing a discharge coefficient of at least 0.9 and walls diverging outwardly from the metering orifice at an included angle not exceeding 3 degrees. The discharge coefficient is defined as the ratio of actual flow to theoretical flow. The ratio of the passage length L to the largest linear dimension of the metering orifice 34 is within the range of 3 to 1. The supply passage 16 is formed between a jacket 14 and a core 12. The discharge passages 30 are defined by the inner surface 40 of the jacket 14 and grooves of V or U crosssection on the outer surface of the core 12. The outer wall of each passage 30 is parallel to the nozzle axis and its inner wall is inclined thereto at an angle not exceeding 3 degrees. The metering orifices 34 are defined by the entrances to the discharge passages 30. Cutting oxygen is supplied to the central passage 20 of the core 12. The discharge passages may be formed by tapered bores of circular section.