GB1337137A - Regenerative heat-exchanger matrices - Google Patents

Abstract

1337137 Heat-exchanger matrices; shearing BRITISH LEYLAND TRUCK & BUS DIVISION Ltd 11 Jan 1972 [20 Jan 1971] 2775/71 Headings B3A and B3W [Also in Divisions B5 C1 C7 and F4] A method of manufacturing a regenerative heat-exchanger matrix having a multiplicity of substantially parallel, open-ended, tubular fluidflow ducts comprises fabricating a multiplicity of rods 23, Fig. 1, of circular or polygonal crosssection each having a filamentary polymer core within a shell of refractory material, forming a compacted assemblage of the rods, and heating the assemblage to remove the polymer cores and thus create fluid-flow ducts. A polymer monofilament 1 is drawn from a spool 2 through a sizing die 4 and a reservoir 6 containing a suspension 7 of a refractory material, e.g. metallic or ceramic powders such as stainless steel, alumina, glass-ceramic and silicon. The solvent may be aqueous or organic and includes binding agents. The coated filament is then partially dried by jets 14 of cold air followed by passing through a device 15 to which warm air is supplied by pipe 16. Then jets 18 of cold air are directed on to the filament before it is severed into rods by a conveying device 22. This device comprises a pair of duplex endless chains 25, 25A which accommodate cutting elements 26 and anvils 27. Each anvil has a V-shaped notch (27A), Fig. 2 (not shown), conforming to bevelled portions (26A), (26B) of element 26, the central zone of the notch having a cut-away portion 33 to receive the filament 1. The stationary cams 29 cause a gradual gripping of the filament prior to the cutting into rods 23. The rods are then packed into a device 26, Fig. 3, comprising a casing 37, respective top and bottom plates 39, 38, a refractory core 40 and a moulded rubber annulus 42. The annulus is held in a rigid container 43 which has an array of holes 45 in its wall to allow pressurized fluid from inlet 44 to pressurize the annulus and hence compact the assemblage of rods into hexagonal, coated rods (23A), Fig. 5 (not shown). The assemblage is then heated to remove the organic filamentary core of each rod and the rods are subsequently sintered or heat treated in a reactive atmosphere.