Method of producing a nucleate boiling surface on a heat transfer member

Abstract

Improved heat transfer surface for nucleate boiling is produced by metallizing a reticulated organic foam layer placed in contact with a tube or other heat transfer surface so as to form a reticulated metal surface layer which is integrally bonded to the heat transfer surface. The metallized foam layer is then at least partially pyrolyzed to form hollow metal strand portions. The boiling surface so produced is then modified to enhance its long term boiling stability by deforming the hollow strand portions to reduce their minimum internal diameter. In one manufacturing process, suitable small solid particles, which may or may not be permitted to remain in the finished product, are worked into the porous surface of the reticulated metal layer after which the layer is compacted so as to cause the particles to deform the hollow metal strand portions and thereby reduce their ability to carry liquid flow which could "flood out" vapor bubbles trapped in the tips of the hollow strands during a boiling operation. In another process, the reticulated metallic layer is bombarded with pellets such as steel shot which can deform the hollow metal strands and reduce their ability to transport liquid.

Dependencies are inferred from the claim text.