Thermoelectric heat pumping apparatus

1,050,798. Thermoelectric devices. WESTINGHOUSE ELECTRIC CORPORATION. Oct. 16, 1964 [Oct. 30, 1963; Dec. 20, 1963], No. 42334/64. Heading H1K. A thermoelectric device comprises two layers of dissimilar thermoelectric material in thermal and electrical contact with a first pair of opposed surfaces of a junction block which has a passageway, extending between another pair of opposed surfaces, through which heat exchange fluid passes. As shown, Fig. 5, a thermopile 11 comprises a plurality of layers of P- and N-type thermoelectrical material, each layer comprising nine pellets of, for example, bismuth telluride soldered between copper or aluminium blocks 51. These blocks are arranged in columns separated by strips 86, 88, 90 of insulating material and interconnected at top and bottom by bridging straps 84, 91, 92, 94, 96, 100 so that all the layers are connected in series between terminals 80 and 82. The layers are arranged so that the blocks 51 at the same horizontal level are either all heated or all cooled, and so that the heated and cooled levels are arranged alternately. Each block 51 has a horizontal bore 57, and the insulating strips 90 separating the blocks have apertures through which pass insulating tubes 104 which are sealed in enlargements at the ends of bores 57 by O-rings 106, Fig. 6 (not shown), to form passages through the device. The front and rear blocks in each row have tubular extensions 59 which receive the ends of insulating conduits 61 which interconnect the passages in the blocks to form two circuits, one comprising a series connection of the passages in the heated levels and having inlet and outlet conduits 63 and 65, and the other circuit comprising a series connection of the passages in the cooled levels and having inlet and outlet conduits 69 and 71. The outside of the pile 11 may be cased with insulating material 110 to prevent arcing between elements. An air cooling system using the above device 11 is described with reference to Fig. 4 (not shown). In a first modification, Fig. 10 (not shown), the strips of insulating material separating the columns of thermoelements are replaced by a cast insulating material 150 applied to the assembled device in the form of a powder or powder-liquid suspension so that on setting a unitary mass is produced. In a second modification, Fig. 7 (not shown), the thermopile 120 comprises a single stack of thermoelements 130 and plates 122, each plate having a plurality of parallel passages 126 for the