| 摘要 |
Heat storage material for a rotary thermal regenerator or a plate heat exchanger comprises plates of thermoplastic weldable plastics material, each having a plurality of projections 6, 7, 8 integrally formed with the plate, which are welded by ultrasound or friction welding or by hot wires to form a stack in which the surfaces of the plates are welded to the tips of the projections on the adjacent plate surfaces and held at a spacing. The plates are formed by extruding a flat sheet (22), which is then passed between rotating cooled rollers (23, 24), at least one of which has peripheral moulding recesses (26) for forming the projections, the recess and projections preferably being tapered to facilitate release of the projections. A hot wire may be moulded into a continuous surface projection from the sheet, by magnetically retaining the wire within a roller recess which moulds the continuous projection. <IMAGE> |
