Thermoelectric apparatus

1,066,528. Thermoelectric devices. WESTINGHOUSE ELECTRIC CORPORATION. Dec. 2, 1964 [Dec. 20, 1963], No. 49010/64. Heading H1K. In a thermopile either the hot or the cold junction members have passages for a heatexchange fluid, the passages being connected in series by coupling members at least one of which includes means for absorbing expansive and compressive forces. As shown, Fig. 1, a thermopile 10 comprises three rows of thermoelectric devices connected electrically in series, each row comprising a plurality of layers 32, 34 of N and P-type thermoelectric material connected in series by fin structure 24 and upper and lower rows of blocks 12 which may be of aluminium or copper. The layers 32, 34 are arranged so that the blocks 12 are heated and the fin structures 24 are cooled. Blocks 12 have aligned bores 14 for a cooling liquid, and the bores of adjacent blocks are connected in series by bellows members 46 which may be of a material having a relatively high electrical resistance (defined) such as certain specified alloys. The fin structures 24 each comprise two base members 26 connected by fins 28 which cool the air flow between them. The layers 32, 34 of thermoelectric material each comprise a plurality of pellets of bismuth telluride soldered or brazed to the adjacent surfaces of blocks 12 and base members 26. The blocks 12 at the ends of each row have tubulations 52 which receive the ends of insulating conduits 50, 54, 56, 58 which connect the bores 14 in series to provide a cooling circuit for the hot junctions. The three rows of devices are mounted between two plates 60 which have grooves 62 to locate the rows of blocks 12 and are clamped together by tierods 66. Plates 60 may be of insulating material or else of metal provided with insulating linings 64 for the grooves 62. In a modification, Figs. 2 and 3 (not shown), the straight fins (128) are more widely spaced and the gaps are filled with corrugated fin structures (132), the top and bottom faces of the blocks (112) are cylindrical and the grooves in the plates (106) are correspondingly shaped, there are only two rows of thermoelectric devices, and the tie-rods (104) are located between the two rows. In an additional modification, Fig. 5 and 6 (not shown), the fin structures are replaced by metal blocks (220) which have aligned bores (226) through which a liquid to be cooled is passed. The aligned bores (218, 226) in both the heated and cooled blocks are joined by members (228) each comprising