| 摘要 |
In a corrugated metal sheet of the type that is adapted to have the edges of recesses which are located at the crests of the corrugations engaging a tube for establishing heat transmitting contact between the metal sheet and the tube, each recess in the metal sheet is so much smaller than the geometrical figure inscribed by the line of engagement between the metal sheet and the tube that an annular edge portion will be formed between the recess and the line of engagement. As a result, the recess despite manufacturing inaccuracies will bear with the whole extent of its edges against the tube, the excess material at the edges of the recess being brought to form an edge flange facing the tube. |
