Patent GB-707592-A (GB)
Title: Thermochemical scarfing devices
IPC: B23K7/06
Filed: 1951-08-07
Abstract: 707,592. Removing surface metal by blowpipes. UNION CARBIDE & CARBON CORPORATION. Aug. 7, 1951 [Aug. 17, 1950], No. 18615/51. Class 83 (4). [Also in Group XI] In a desurfacing head for flame-scarfing metal bodies comprising a nozzle providing a slot adapted to discharge a sheet-like stream of cutting oxygen, preheating flames from externally mixed fuel gas and preheat oxygen are formed along at least one side of the cutting oxygen stream by one or more detachable burner members containing separate preheat oxygen and fuel gas passages leading to a plurality of spaced preheat oxygen orifices arranged equidistant from the cutting oxygen discharge slot and to a plurality of fuel gas orifices adjacent the preheat oxygen orifices. The desurfacing head comprises a manifold block 10, spud plate 15, a nozzle block 12 and two parallel rows of nine preheat blocks 20, 21 bolted to the front of the nozzle block, one row on either side of a deep rearwardly extending groove 16 in which a stainless steel or refractory insert 17 forming an outlet slot for cutting oxygen is secured by bolts extending through the back of the nozzle block, the upper preheat blocks 20 being disposed forwardly of the lower preheat blocks 21. The preheat blocks have plane surfaces which co-operate with a plane surface on the nozzle block 12 such that separate fuel gas and preheat oxygen outlet apertures in the nozzle block register with respective inlet apertures in the preheat blocks. Each upper preheat block 20, Figs, 6, 7, has a row of bores 22 in which are fitted removable cylindrical inserts 24 each having a central bore 25 extending into a preheat oxygen manifold 30 in the block, and two longitudinal grooves connected to an annular groove 28 communicating through a passage 32 in the block with an acetylene gas manifold 33. Cooling water circulates in the passages 36 ... 40 in the block. The lower preheat blocks 21 have similar inserts 24 and passages for oxygen and acetylene. The cutting- oxygen insert 17, Fig. 10, comprises a rear section 45 having a plurality of longitudinal parallel bores 47, 49 extending forwardly from a plurality of transverse chambers 46 supplied with oxygen through passages 59 in the nozzle block terminating in apertures at the base of the deep groove 16. The bores 47 are of stepped diameter with the smaller ends entering the chambers 46 but the bores 49 extending from the outermost chamber 46 at one or both sides of the insert are of uniform diameter larger than the smaller diameter of the stepped bores to provide a flow adequate for corner conditions in four-sided scarfing. The remainder of the insert is formed by an upper plate 52 which extends beyond a lower plate 53 to form an overhanging lip 18 and is spaced from the lower plate by partitions 54 terminating short of the mouth. The edges of the lower plate are turned up to form side walls. The cutting oxygen, the acetylene and the cooling water are conveyed from the manifold block 10 through registering passages in the manifold block, spud plate and nozzle block. The cutting oxygen passes from the manifold chamber 56 along passages 57, 58, 59 to the chambers 46 in the insert 17. The manifold chamber 56 may contain a selector valve for cutting off some of the passages 57. The acetylene passes from the manifold chamber 60, which may also have a selector valve, through passages 62... 65 to the acetylene manifolds 33 in the upper preheat blocks 20 and through passages 62, 63, 64, 66, 67 to the acetylene manifolds in the lower preheat blocks 21, the passages 66, 67 extending around the back of the insert 17. The preheat oxygen is supplied by an inlet 69, Fig. 2, to a manifold passage 70, Fig. 1, in the spud plate and is then conveyed by passages 71 .. 73 to the upper preheat blocks and by passages 71, 72, 74 to the lower preheat blocks. Six of each nine upper and lower preheat blocks are controlled by six cut-off valves 75 disposed in the preheat oxygen passages 71 and operated by handles 77 at the front of the spud plate. Water passes from a chamber 78 in the manifold block 10 through a passage 79 in the spud plate to a passage 80 in the nozzle block and hence by a passage 81, Fig. 2, in an end plate 83 on the nozzle block to a manifold passage 82 through which pass hollow bolts 85 securing the lower preheat blocks 21 to the nozzle block. The water enters the hollow bolts through lateral bores 87 therein and after circulating in the passages in the lower preheat blocks passes to a return manifold 90 in the nozzle block. This return manifold 90 is connected by a passage 91 in the end plate 83 to an upper return manifold 92 connected by passages 97, 98 to a return chamber 99 in the manifold block. The manifold passage 82 is also connected by a passage 93 in the end plate 83 to an upper inlet manifold 94 connected by passages 95 to the upper preheat blocks, the water being returned by passages 96 to the upper return manifold 92. The bottom of the nozzle block has skids 41. In a modified construction, Fig. 18, adapted for the desurfacing of cylindrical stock cutting oxygen is admitted to an annular chamber 112 provided with spring-cushioned skid plates 151 and passes through bores 149 in the spud ring 115 to a conical slot 117 between a nozzle ring 110 and an inner preheat ring 121. An outer preheat ring 120 is bolted to the nozzle ring and extends forwardly of the inner preheat ring. The cutting oxygen discharges between the inner and outer preheat rings. The outer preheat ring has a series of bores 122 disposed as elements of a cone extending into an annular preheat oxygen chamber 170. Inserts which are identical with the inserts 24, in the previous construction are disposed in the bores 122. Acetylene is supplied through passages 132 from an annular chamber 133. An annular cooling chamber is supplied by an inlet 199. The inner preheat ring has a conical series of bores 167 leading from an annular fuel gas chamber 166. Air orifices are provided rearwardly of the fuel gas bores and communicate with an annular air chamber 172. An annular cooling chamber 187 is provided. Specification 658,695 is referred to.