| 摘要 |
<p>A heat exchanger, e.g. for a condensing gas boiler for a central heating system, comprises a plurality of interfitting lengths of an aluminium alloy extrusion affording a tubular part 10 to receive, as a liner, a water pipe 42, and affording a plurality of parallel fins 26 extending from webs 22, 24, projecting from part 10. The extrusion also affords flanges 30, 38 allowing adjoining lengths of extrusion to be bolted or otherwise fixed together. The interfitting extrusion lengths are secured between end plates 40 which bound a circuitous passage for combustion gases, passing over the fins 26. The invention affords an economical way of constructing an efficient heat exchanger. <IMAGE></p> |
