Abstract: This invention is directed to an external loop nonfreezing heat exchanger for cooling a heat transfer fluid with cryogenic fluid. The cryogenic fluid is first pre-vaporized with the spent cryogenic fluid. The heat transfer fluid is then cooled by the vaporized cryogenic fluid instead of the cryogenic fluid feed directly.

Abstract: This invention is directed to an external loop nonfreezing heat exchanger for cooling a heat transfer fluid with cryogenic fluid. The cryogenic fluid is first pre-vaporized with the spent cryogenic fluid. The heat transfer fluid is then cooled by the vaporized cryogenic fluid instead of the cryogenic fluid feed directly.

Abstract: A heat exchanger unit having a housing into which a cryogenic liquid is introduced and permitted to evaporate and vaporize into a cryogenic cold gas. A process fluid to be cooled flows in a heat exchanger and heat exchange to cool the process fluid takes place between the cold gas and the heat exchanger, without making direct contact between the cryogenic liquid and the heat exchanger which would cause freezing. The refrigerating capacity of the cryogenic cold gas is replenished by heat exchange contact with the evaporating cryogenic liquid.

Abstract: A cryogenic cooling tower in which a process liquid from which heat is to be removed is supplied to the tower interior that has a plurality of plates vertically stacked one above the other, alternating in opposite directions and tilted downwardly at an angle relative to the tower vertical axis. A cryogenic cooling medium is supplied to the tower interior. The process liquid forms a film on the upper surface of the plate and drops from its front end to the next lower plate. While on a plate the process liquid spread into a film provides a greater surface area to react with the cooling medium to effect the heat transfer. The tilt angle of the plates can be adjusted to control the residence time of the process liquid in the tower.

Abstract: A cryogenic cold shelf for use in a freeze drying system having a cryogen distributor for passing cryogenic fluid into the shelf volume of the cold shelf at differing rates so as to even refrigeration provided over the entire shelf resulting in a uniform temperature over the cold shelf.