GB705347A - Process and apparatus for thermochemically removing surface metal - Google Patents

Abstract

705,347. Removing Surface metal by blowpipes. UNION CARBIDE & CARBON CORPORATION. May 9, 1952 [June 6, 1951], No. 11919/52. Class 83 (4) In a process for scarfing an oxidation resistant body by applying preheating flames, a wide flat stream of oxidizing gas and astream of combustible metal powder against a surface of the body and advancing the scarfing means-comprising the flames, oxidizing gas andpowder streams successively along adjacent overlapping paths, the cutting action of at least one edge portion of the stream of oxidizing gas is weakened by introducing into it a stream of relatively inactive gas, e.g, air, nitrogen, argon and the like. In an embodiment, a nozzle N having two rows of preheat flame apertures 17 above and below a wide oxygen orifice 15, is secured by a nut 13 to a head 10 having oxygen and preheating gas inlets. 11, 12. An adjuvant powder nozzle P with a wide orifice 21 is bolted on a bracket 25 .secured-2o a clamp 22 on the nozzle N. A cylindrical air -nozzle - 6 is brazed at 34 to a lug 30 on the clamp 22 to be in the plane. containing the axis 28 of the nozzle N and the long axis of the orifice 15 but being at an angle X preferably 5-30 degrees, to the axis 28. The air stream meets the oxygen stream downstream from the meeting point of the oxygen and powder. The axis 28 is inclined to the work surface at an angle Z, preferably 30-50 degrees and the nozzle P is inclined to the axis 28 at an angle preferably 25-40 degrees. 'The nozzle N may be water cooled and a slotted nozzle may be employed where the powder is internally mixed with the stream of oxidizing gas.