Horizontal finned heat exchanger for cryogenic recondensing refrigeration

摘要

A cryogenic system includes a superconducting magnet (20) in a reservoir of liquid helium (LH). Helium vapor (VH) rises and contacts a recondenser surface (50, 50′, 50″) on which the helium vapor (VH) condenses into liquid helium and flows by gravity off a lower edge of the recondenser surface. A plurality of fins (52) extend from the recondenser surface or a plurality of grooves (52′, 52″) are cut into the recondenser surface to disrupt the film thickness and to provide a path by which droplets of the liquid helium leave the recondenser surface without travelling a full vertical length of the recondenser (30).

主权项

1. A cryogenic system comprising:
a liquid helium vessel containing liquid helium (LH); superconducting magnet windings immersed in the liquid helium; a helium vapor recondenser with a smooth surface recondenser in which helium vapor recondenses which recondenser surface is intermittently interrupted by an interrupting structure which at least one of causes liquid helium which condenses on the smooth surface to leave the recondenser without travelling a full vertical length of the recondenser on the smooth surface and disrupts a thickness of a liquid helium film forming on the recondenser surface, wherein the interrupting structure is a fin that extends in a spiral along a length of the recondenser, wherein the fin has a sloping upper surface which slopes downward away from an adjacent recondenser surface portion and a bottom surface, wherein the upper surface and bottom surface meet and terminate along a line that forms a sharp drip edge from which liquid helium droplets leave the recondenser surface without travelling a full length of the recondenser surface.