GB944874A - Thermo-electrical generator - Google Patents

Abstract

944,874. Transformers; thermo-electric generators. C. F. R. VON KOCH. Aug. 15, 1960 [Aug. 20, 1959; Jan. 18, 1960], No. 28213/60. Headings H1K and H1T. In a thermo-electric A.C. generator, one or more thermocouples is or are intermittently heated, and the thermocouple circuit, which is free from slip rings and periodic switching contacts, comprises a primary winding of a transformer. As shown, Fig. 5, the core A of a transformer comprises three legs, one of which is provided with a secondary winding F while each of the other legs is surrounded by a rotatable thermo-electric ring R. Each ring R, Figs. 6, 7, comprises two dished plates 1 of a first thermo-electric material joined to form a shell having two projecting portions 2, and wires 4 of a second thermo-electric material, each wire being joined to the shell at the peripheries of portions 2 and wound to provide one or more primary turns around core A. Portions 2, which may be provided with corrugations or ribs (not shown), pass cyclically through one or two flames as the rings are rotated in synchronism, thus producing current pulses, the A.C. component of which is available at the terminals of secondary winding F. Points of equal temperature on plates 1 may be joined by highly conductive wires. Fig. 3a shows a thermoelectric ring R comprising four thermo-couples in series, each having a cold junction K and a hot junction W, the latter projecting radially and axially from the ring and being heated by a burner B. If the ring rotates at 12.5 r.p.s. the A.C. produced has a frequency of 50 c.p.s.; a plurality of burners, and/or a different speed of rotation, may produce a different frequency; moreover, lower harmonics of the fundamental frequency may be utilized. The portions of the ring R in the vicinity of the heated zone may be heat-insulated as by an envelope I. In the modification shown in Fig. 4b a larger number of thermocouples, e.g. twenty-four, form the ring R, the hot junctions W projecting axially from the ring and being heated by a burner through an aperture in a heat shield S. Rapid cooling of the hot junction after the heating period is achieved by radiation and convection, by thermo-electric cooling by the current which continues to flow immediately after the heating period, and by forced cooling, e.g. by air or water. The ring R may be rotated by the pressure of gas emitted by the burner(s), or by an electric motor, preferably supplied with the harmonics of the generated A.C.; or excess heat produced by the burner(s) may drive a propeller to rotate the rings and/or circulate cooling air or water. Alternatively, the rings may remain stationary, the intermittent heating being produced by pulsating flames, a rotating shield, &c. The highest temperature attained by the hot junction should be higher than the material of the junction could withstand continuously, and should be over 1000‹ C., preferably at least 1500‹ C. and, if possible, over 2000‹ C. The thermo-electric materials used in the generator may consist of metal, alloy, metal compounds and semi-conductor material.