Application of high-temperature vacuum-brazing for fabrication of compact shell-and-tube heat exchanger

The use of high-temperature vacuum-brazing for the fabrication of compact shell-and-tube heat exchangers to minimize mismatching of the gap between the tube and the hole in the plate is described. The probability of gap mismatch increases with increasing tube plate thickness. In vacuum-brazing the brazing gap is filled with metal powder before brazing. For high-alloy and carbon steels, iron and iron-nickel alloy powders are suitable fillers. Brazing conditions are described.