Patent GB-507279-A (GB)
Title: Improvement in blowpipe apparatus
IPC: B23K7/06
Filed: 1938-09-24
Abstract: 507,279. Blowpipe burners ; removing surface metal. LINDE AIR PRODUCTS CO. Sept. 24, 1938, No. 27880. Convention date, Nov. 13, 1937. [Class 75 (i)] [Also in Group XXII] A blowpipe apparatus for removing a surface layer from steel slabs, billets, blooms, &c. comprises a header block formed with one or more chambers through which a heating gas mixture is supplied to a row of nozzles fitted in openings in the block and with a plurality of passages for conducting an oxidizing gas'also to the nozzles. In the apparatus shown in Figs. 1, 2 and 3 a heating gas mixture of fuel and oxidizing gas produced by one or more blowpipes W similar to those employed in welding is supplied through openings 31, 33 to two chambers 29 in the header block B and is conveyed by passages 30 to annular chambers 25<1> communicating with eccentric passages in the nozzles N. The oxidizing gas is supplied through a conduit C to one or more chambers 34 in the block B and passes through passages 35 to central gas passages in the nozzles N. Cooling fluid may be circulated through passages 43, 45, 47 in the block B and through the blowpipes W. The nozzles N may be arranged converging to a central point, parallel, or all inclined at a uniform angle toward one side of the slab &c. It is preferable to supply a separate gas chamber 29 and blowpipe W for each group of about four nozzles. The header block may be mounted in a desurfacing machine such as described in Specification 459,290, [Group XXII], comprising a frame D pivoted to a support movable over the work 13. A downwardly projecting arm 14 carries a guide engaging the side of the work. The blowpipes W and a shoe 20 carrying the header block B are secured to a plate 19 mounted as described in Specification 507,259 on a carrier 17 attached by links 15, 16 to the frame D and movable upwards against the resistance of springs 18. The shoe 20 has an abrasion resistant surface 22 engaging the work and is formed with bosses 24 to which projections 23 at the rear of the block B may be bolted. Fig. 5 shows another header block B having three inlets 131 for.heating gas and a single conduit C supplying desurfacing oxygen to both ends of a manifold 134 connected by pipes 135 to passages 35 leading to the nozzles N. Fig. 8 shows a rectangular billet being desurfaced on all four sides, the lower and right-hand shoes being located behind the other two shoes to prevent interference. The nozzles may be all oriented in the same direction or the directions may be varied. The nozzles not required are blanked off by plugs 126. The height of the ridges produced on the work may be reduced by closer nozzle spacing, by greater orientation of the nozzles, or by using nozzles .having flattened or rectangular orifices, so as to produce a continuous gas stream across the work. The nozzles may be supported by means such as described in Specification 507,262, [Group XXII]. Fig. 10 shows a suitable nozzle in which the axial bore 55 for the desurfacing orifice has an expanded portion 58 which reduces the velocity of the gas to say 800 feet per second and a flattened orifice 59 of substantially the same cross-sectional area as the portion 58. Heating gas passages 57 surround the central bore.