Generating Duct for a Magnetohydrodynamic Electrical Generator

1,180,217. Making MHD generator ducts. ROLLS-ROYCE Ltd. 12 July, 1967 [15 July, 1966], No. 31793/66. Heading B3A. [Also in Division H2] A method of making a MHD generator duct comprises providing a first set of templates 10, forming an electrode-defining annular member 2 by taking each template separately and wrapping a tube 11 around the template periphery, arranging one of a second set of templates 18 around the tube, pressing the tube to the thickness of the templates 10, 18 and separating the member thereby formed from at least the inner template 10, forming annular layers of insulation, assembling the members 2 and the insulation layers alternately, and sealingly securing them together. The templates 10 are preferably made by assembling and clamping together flat blank plates and separators (12) the latter having a thickness equal to that of the insulation layers. The assembled pack is then formed to the same shape as that of the duct flow path, Fig. 2 (not shown). The shaped pack is then separated and the tubes 11 are bent around the templates 10 so as to have end portions 3 extending from one corner of the template, which portions are brazed or welded together. The tube is similarly secured to the template 18. The members 2, comprising the tubes 11 and templates 18, are arranged in order and a layer of insulation is arranged between each pair of members. The assembly is clamped together by bolts or the like through the templates 18 and the duct is supported at intervals in apertured plates 21, which also locate troughs 5. The tube end portions 3 are connected to conductor pipes 4, which are bent so as to extend parallel with the axis of the duct and to lie in the troughs 5. Liquid coolant is circulated through the pipes 4 and tubes 11 and collected at the upstream ends 6 of the pipes. The members 2 are preferably located at 45 degrees to the axis of the duct.