GB539470A - Improvements in deseaming or desurfacing metal bodies - Google Patents

Abstract

539,470. Blowpipe burners. LINDE AIR PRODUCTS CO. March 27, 1940, No. 5489. Convention date, April 22, 1939. [Class 75 (i)] [Also in Group XXII] In de-seaming or de-surfacing metal bodies such as billets, blooms, slabs &c. a jet of oxidizing gas at de-seaming or de-surfacing velocity is impinged along and obliquely against the surface and at the same time a jet of oxidizing gas at low velocity is impinged against the surface at one or both sides thereof. The formation of fins at the edges is thus inhibited by oxidizing the molten metal in the slag so as to obtain a brittle slag without damaging the base metal of the work. The de-seaming blowpipe P may have a main nozzle N containing a central oxygen orifice O supplied with oxygen at deseaming velocity, e.g. 500-1,000 feet per sec., surrounded with pre-heating jets H. On the nozzle is mounted a yoke Y having a pair of auxiliary nozzles A supplied with oxygen at low velocity, e.g. from 50-150 feet per sec. The supply may be from a separate source or from the main source through a throttle valve. The yoke may be free to turn on the nozzle so that the nozzles A are automatically held in proper position by resting the yoke on the surface. The nozzles A are inclined downwardly and inwardly with respect to the jet O so as to counteract the tendency of the jet O to blow the hot material over the opposite edges of the surfaces. De-surfacing of a relatively wide surface may be effected by using an apparatus with a bank of nozzles used as N carried by a head with an auxiliary nozzle such as A at one or both sides of the head. Specifications 494,218 and 538,092 are referred to.