GB1048569A - A magneto-hydrodynamic generator - Google Patents

Abstract

1,048,569. Generators and pumps operating by electromagnetic interaction with fluids. COMMISSARIAT A L'ENERGIE ATOMIQUE. Oct. 16, 1963 [Oct. 16, 1962; Sept. 20, 1963], No. 40847/63. Heading H2A. An A.C. magnetohydrodynamic generator comprises two rectangular refractory ducts spaced apart by a magnetic core which forms part of a magnetic circuit and has the ducts joined by lateral connections so that the fluid can circulate around the interposed magnetic core. The magnetic circuit is wound with a primary (exciting) and a secondary winding, the latter being connected to a load. As shown in Fig. 7, ducts 32, 33 are joined by conduits 34, 35 and surround an X-shaped magnetic core 36. Two outer magnetic members 38, 39 are placed on core 36 so that the central poles carrying the exciting winding are adjacent the ducts where these are joined by the conduits. The legs of the outer magnetic members carry secondary windings 41 which are connected to the load (not shown). In operation, both ducts carry ionized gas, seeded with potassium or caesium, flowing in the same direction and the main magnetic field is such as to induce currents in opposite directions in the ducts so a circulating current around the core is formed; the gas in conduits 34, 35 acting as the connection for this current. The exciting field components in core 36 are in opposition and effectively cancel out so that the A.C. current flowing around core 36 will induce an A.C. flux in it which links with coils 41 to produce an output. In the modification shown in Fig. 9, fluid flows in opposite directions in ducts 104, 106 in the presence of an A.C. magnetic field to generate an A.C. current which circulates through connecting conduits 126-136, and links with core member 118 to induce a current in secondary coil 120. The C-shaped member 110 carries the main flux produced by exciting winding 114 and since the primary and secondary fields are perpendicular they do not interact. By making conduits 126-136 of small section compared to the ducts substantial flow of fluid between them is prevented and a baffle arrangement, Fig. 11 (not shown) is used to compensate for any pressure drop in the main duct. To improve efficiency secondary coil 120 may be wound on the limb of core 118 which lies between the ducts. The generator may be self- or separately-excited and is stated to be capable of use as a pump.