GB584808A - Improvements in or relating to apparatus for hardening the surface of ferrous metal articles - Google Patents

Abstract

584,808. Hardening ferrous articles. SHORTER PROCESS CO., Ltd., and SHORTER, N. [Representative of SHORTER, A. E.]. July 21, 1944, No. 13975. [Class 72] Apparatus for hardening an annular or cylindrical zone of a ferrous metal article comprises a plurality of annular tubes arranged in a single layer in proximity to the surface zone to be treated, at least one of the tubes being supplied with combustible fluid and having a row of burners adapted to direct a multi-jet flame on the surface and at least one of the tubes being supplied with quenching fluid or provided with a row of discharge orifices, the rows of burners and discharge orifices being mutually inclined so that the quenching stream impinges centrally upon the zone heated by the burner nozzles. The heat-treating unit comprises a nozzle-type burner 10 with an annular row of nozzles 11 and concentric quenching units 13, 14 whose nozzles 15, 16 are mutually inclined towards the surface S of the article W. A mixture of oxygen and a fuel gas, such as acetylene, is fed to the burners by pipes 21 leading from a distributing unit 18 comprising a chamber 19 connected to a mixing chamber 17 from which the mixture is delivered through passage 20 to the pipes 21. The quenching units connected at intervals by pipes 26 are supplied by pipes 25 through passages 24 from a chamber 22 in the member 18 from an inlet 33. The pipes 21 are cooled by winding around the pipes 26 supplied with cold water from a header 28 mounted on the member 18 and fed by a pipe 29 the water leaving the tubes 27 by outlets 30. The inner quenching unit is secured by lugs 32 to a stiffening plate 31 held centrally by a stanchion 33 secured to the member 18. The member 18 may also serve as the means by which the whole unit is supported in the operative position and is provided with control means for moving the apparatus automatically into position with respect to the surface to be treated as described in Specification 584,791, in which is also described suitable valve mechanisms in the fluid supply lines. For hardening a cylindrical surface zone S<SP>1</SP>, Fig. 2, the tubes 10, 13, 14 are arranged in a cylindrical plane with the burner nozzles 11 directed inwardly to produce a radial flame and the quench orifices 15, 16 mutually inclined towards the nozzles 11.