| 摘要 |
1,204,035. Welding by fusion; making heat exchangers. SOC. FIVES LILLE-CAIL. 4 Jan., 1968 [4 Jan., 1967; 2 March, 1967; 2 Oct., 1967], No. 691/68. Headings B3A and B3R. Tubes 12 are welded to a tube plate 10 by weld surfacing substantially the whole of one face of the plate 10, the surfacing connecting the tubes 12 and the plate 10. The tubes 12 may project from, be flush with, or be slightly withdrawn from the surfaced face of the plate 10. During surfacing the ends of the tubes are blocked by plugs 14 which project from or are flush with the ends of the tubes. The plugs 14 may be cylindrical, conical or flanged and of weldable metal or non-weldable material, e.g. copper, tungsten, sand quartz or glass. The plugs are removed by boring or destroyed by impact. The plugs may be tightly fitted or supported by circlips or may consist of flux or other powder supported on slugs held by circlips. The whole face of the plate may be surfaced by submerged are welding overlapping parallel beads using, e.g., twin oscillating wires or a strip as filler material. Alternatively, as shown in Fig. 4, beads may be deposited in two overlapping directions to cover the face of the plate and all or part of the ends of the plugs. In a modification the plate 10, Fig. 8, is disposed vertically and an iron bar 28 is welded to one side of the plate. Adjacent vertical beads 16 are deposited by electroslag welding using an L- sectioned water-cooled copper shoe 26 and a consumable guide 18 consisting of a web joining tubes guiding electrode wires, the guide being located by a zig-zag ribbon or by pads of asbestos. Alternatively consumable guide tubes insulated by asbestos, glass wool or flux may be used. After the plate has been surfaced, the surfacing is machined or bored to expose the plugs. In a further modification the tubes 12, Fig. 12, terminate at a counter-plate 30 spaced from the plate 10 and the space is filled by electroslag welding using electrodes 34 fed through consumable guide tubes 32. Surfacing may also be effected by vertical submerged arc welding. |
