| 摘要 |
<p>A heat exchanger mainly for domestic hot water supply is built up from six heat exchange units 1, each comprising an outer tube 2 and a coaxial inner tube 3 defining a passageway 4 therebetween for flow of water to be heated. The ends of the inner tubes 3 extend beyond the ends of the outer tubes 2 containing them and include couplings 5 serving either for connection with an inlet or outlet 6 for boiler flow and return, or for coupling with other inner tubes as at 7. <IMAGE></p> |
