The refrigeration available in a liquefied gas is utilized to refrigerate a fluid having a boiling point above the boiling point of the liquefied gas which is sprayed into an endless conduit such that the liquefied gas is vaporized. The resulting thermal currents and momentum of the spray are effective to provide the motive power for circulating the gas throughout the conduit and into indirect heat exchange with the fluid to be refrigerated. The temperature of heat exchange means in the vicinity of the location at which the fluid is introduced into such indirect heat exchange may be regulated by controlling the magnitude of the gas flow throughout the conduit to thereby avoid freezing of components of such fluid. The use of shaft power (such as a fan or blower) for circulating the gas flow throughout the conduit is avoided and the utilization of refrigeration available in the liquefied gas is improved accordingly.
Process for the transfer of refrigeration from a cryogen to a heat load via an intermediary fluid utilizing heat exchangers wherein the intermediary fluid is maintained together with an inert gas in a closed loop, which has a defined volume.
A device for generating a dry, cold air flow in the treatment of rheumatic diseases includes a cyclone separator as its heat exchange device. The intake line of the cyclone separator is connected to the outlet line of the blower means of a line in which the cryogenic liquefied gas feed ends. The outlet opening of the cyclone generator has attached to it an insulated flexible hose.
A vapor recovery apparatus consumes a source of liquified gas to condense vapors in a source of vapors. The apparatus includes an economizing heat exchanger and a finishing heat exchanger. The economizing heat exchanger has a vapor path adapted to be connected to the source of vapors, and a recovery path for exchanging heat with, and cooling vapors in, the vapor path. The finishing heat exchanger has a finishing path connected downstream of the vapor path of the economizing heat exchanger, and a coolant path adapted to be connected to the source of liquified gas for cooling and condensing vapors in the finishing path. The coolant path is isolated from the finishing path to avoid interpath mixing. The finishing path is connected to feed the recovery path of the economizing heat exchanger.
A treatment chamber for a charge comprises at least oen door, internal walls delimiting a treatment space, passages for the recirculation of gas, and apparatus for circulating gases in the treatment space and the passages. The circulating apparatus extracts the gases from the treatment space (4) and sends them through the passages (9, 9'). The chamber is provided with injectors (12) for cryogenic fluid and an outlet (16) for evacuation of gas. The injectors are at least one nozzle (12) to spray liquid nitrogen or carbon dioxide and are disposed adjacent the circulating apparatus, which is in the form of a fan (8), the injectors (12) being directed toward the inlet of this fan. In the corresponding treatment process, a cryogenic gas is circulated through the charge, a cryogenic fluid e.g. liquid carbon dioxide or liquid nitrogen is injected into the gas flow leaving the charge, and the cooled gas is recirculated so as to cause it to pass again through the charge in the same direction. All contact between the gas and the charge is prevented during its recirculation.
The refrigeration system according to the invention includes a vacuum jacketed pressure vessel which contains both a spray heat exchanger and a shell and tube heat exchanger. The spray heat exchanger includes one or more nozzles for directing a first refrigerant at a heat exchanger element conveying a second refrigerant. The first refrigerant is sprayed in a fine mist from the nozzles onto the heat exchanger element conveying the second refrigerant. The first refrigerant then evaporates and cools the second refrigerant within the heat exchanger element. The shell and tube heat exchanger is a counter current heat exchanger which includes an inner tube for conveying the second refrigerant to the spray heat exchanger, and an outer tube surrounding the inner tube for conveying the first refrigerant recovered from the interior of the vacuum jacketed pressure vessel out of the pressure vessel. The spray heat exchanger recovers the heat of vaporization of the primary refrigerant, while the shell and tube heat exchanger recovers the enthalpy remaining in the evaporated first refrigerant.
