GB968221A - Improvements in magnetohydrodynamic devices - Google Patents

Abstract

968,221. Generators operating by electromagnetic interaction with fluids. AVCO CORPORATION. Oct. 19, 1961 [Oct. 26, 1960; Dec. 2, 1960], No. 37497/61. Heading H2A. [Also in Division B5] In a magnetohydrodynamic generator the working fluid (hot ionized gas) passes through a duct whose walls 18 comprise a number of spaced longitudinally extending metal bars 19, e.g. copper, separated by insulating material 20, so that an acceptable wall working temperature is maintained. In a generator, having negligible Hall effect so that no longitudinal currents are formed, the walls as described above are clamped between electrodes 14, 17 (14 of carbon, 17 of copper) by bolts 25 and cooling fluid circulated through both electrodes and walls by tubes 23. The electrodes may comprise a number of separate parts distributed along the length of the duct to ensure a uniform current distribution. when the Hall effect is not negligible thermally conductive rods are used (Figs. 7 and 8, not shown) which project from a cooling passage formed by two spaced plates of insulating material and are surrounded within the duct by ceramic filling, e.g. " Blazecrete " (Trade Mark). The rods, which may be of any shape, are cooled by coolant being forced through channels incorporated in them by the pressure difference produced across the rod when coolant flows in the passage. In a generator operating under constant conditions the cooling conduits may be designed to follow the equipotential lines in the working part of the duct and the conduits are embedded in the wall of the duct and separated by the refractory lining of the duct (Fig. 12, not shown). In all constructions the thickness of the bar or rod is such that the voltage induced across it is less than that required to strike an'arc discharge between bars or rods and the risk is further reduced by chamfering the facing comers.