Finned tube heat exchanger - formed by hard soldering aluminium plate fins with tubular flange apertures to aluminium or copper pipe

摘要

In a finned tube heat exchanger with thin plates each having an aperture through which the tube passes and being soldered to the tube and being covered, at least partly, by a layer of solder, (a) at least a part of the edge of the aperture in each plate or fin merges into a projection particularly a tubular projection surrounding the tube and (b) in the region of the part of this edge facing the tube the solder layer is omitted or is considerably thinner than in the adjacent part of the plate. Only the solder at the soldering position is melted during the soldering operation so that deformation or damage to the heat exchanger is not caused thereby. The tube may be of Al or Cu and the fins or plates may be of Al. As a hard solder, the Al-Si alloy eutectic or sub-eutectic is pref.