摘要 |
1. Process for the manufacture of a flat heat exchanger made from sheet metal and having at least one channel through which a medium which is to heated or cooled passes, in particular a roof skin for absorption of energy from the environment, in which process a metal block, preferably consisting of copper, and having at least one passage produced by drilling is first manufactured, a welding preventative is introduced into each passage, the metal block is stretched in the direction of the path of the passage(s), by rolling, to the final dimension, and thereafter each passage which has been rolled flat is inflated, characterised by the combination of the following features : a) the passages are produced in the metal block by drilling a deep hole from both end faces, and b) the metal sheet is soft-annealed in a tunnel-type annealing furnace, prior to the last reduction stage, which is effected by col-drolling in a manner known per se, and the last reduction stage is effected in the same pass as the annealing. |