The present invention relates to a cryocooler suitable for gas liquefaction applications, that comprises a coldhead (1) with one or more refrigeration stages (2, 3); further comprising: a refrigerator compressor (4) for distributing compressed gas-phase cryogen inside the coldhead (1); a heat exchanging coil (9) arranged at least partially around the external region of the coldhead (1); at least one extraction orifice (8) communicating a gas circulation circuit (5) inside the coldhead (1) with the heat exchanging coil (9); acting said extraction orifice/s (8) as pass-through port/s which allow the gas inside the coldhead (1) to flow through the inside of the heat exchanger coil (9) for exchanging heat with the exterior thereof, and wherein the heat exchanging coil (9) is adapted to connect and redirect the gas to one return port (8) connected to the gas circulation circuit (5). Another object of the invention relates to a cryogen-gas liquefaction system (11) and a method for liquefaction of gases that comprises said system (11).

Cooling system, preferably adapted for use in or including a refrigeration plant and/or liquefier plant, having a refrigeration circuit (1) configured to use a refrigerant including a mixture of helium and neon; wherein the refrigerant is based on a raw mixture, preferably is the raw mixture, including helium and neon, extracted from air by an air separation plant (2). Method for producing a refrigerant usable in a refrigeration circuit (1), comprising: extracting a raw mixture including helium and neon from air, wherein the raw mixture preferably further includes nitrogen and hydrogen; and using the raw mixture as the refrigerant or obtaining the refrigerant from the raw mixture.

An expansion turbine configured such that even when pressure of process gas steeply changes, the amount of process gas leaking from a gap between an impeller and a cover is made small. The expansion turbine includes a gas supply passage which is connected to any one of a gas supply passage and a gas discharge passage and through which gas is supplied to a region located between a rotor member and a casing member.

The amount of consumption of gas is reduced when the gas is expanded to be cooled by using a plurality of expansion turbines. A high-pressure expansion turbine includes: a gas supply passage through which bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. A low-pressure expansion turbine includes: a gas supply passage through which the bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. The bearing gas discharged from the gas discharge passage of the high-pressure expansion turbine is supplied to the gas supply passage of the low-pressure expansion turbine.

An arrangement comprising at least one liquefaction plant for liquefying a gaseous medium to produce a liquefied medium; and at least one storage tank for storing the liquefied medium. A first transfer line is provided which is connected between the liquefaction plant and the storage tank, for transferring liquefied medium from the liquefaction plant into the storage tank. A second transfer line is connected between the liquefaction plant and the storage tank, for transferring gaseous medium from the storage tank into the liquefaction plant. The second transfer line, which used for transferring medium from the storage tank into the liquefaction plant, is arranged so that it is routed at least partially through the area of the storage tank in which the liquefied medium is stored in use.

The invention relates to a facility for producing liquid helium from a source gas mixture substantially comprising nitrogen and helium. The facility includes a cryogenic purifier including a system for separating the nitrogen from the source gas mixture with a view to producing helium at a temperature lower than the temperature of the source gas. The facility also includes a helium liquefier that subjects the helium to a work cycle including, in series: compressing the helium, cooling and decompressing the compressed helium, and reheating the cooled, decompressed helium. The facility includes a helium transfer pipe connecting an outlet of the purifier to an inlet of the liquefier in order to transfer helium produced by the purifier into the work cycle of the liquefier. The facility is characterized in that the cryogenic purifier includes a decompression system that includes an inlet to be connected to a source of pressurized nitrogen gas. Said system for decompressing the nitrogen gas exchanges heat with the separation system in order to transfer cold from the decompressed nitrogen gas to said separation system.

The invention relates to a method for low-temperature cooling/liquefaction of a working fluid, in particular a working fluid including helium or consisting of pure helium by means of a refrigerator/liquefier that includes a working circuit provided with a compressor station and a cold box. The refrigerator/liquefier subjects the working gas within the working circuit to a cycle that includes, in series: compressing the working fluid within the compressor station, cooling and decompressing the working fluid in the cold box, and heating the working fluid with a view to the return thereof to the compressor station. The compressor station includes one or more compression levels, each one using one or more compressors mounted on landings. The method is characterized in that the refrigerator includes a device for injecting a seal gas that is separate from the working fluid on at least one landing of the compressor(s) so as to form a gas seal that guides the working fluid leaks, coming from the working circuit, to an area for recirculating and returning the fluid into the working circuit.

A system and a method for recovery and recycling of gases which are utilized in their liquid state as refrigerants in applications that require low temperatures, throughout various pressure ranges, from slightly above atmospheric pressures to pressures near the critical point for the particular gas. The system and method are based on closed-cycle cryocoolers and utilize the thermodynamic properties of the gas to achieve optimal liquefaction rates.

A method of cooling a process stream with an auxiliary stream is described, wherein the exchange of heat between the process stream and the auxiliary stream is effected in a first heat exchanger and a second heat exchanger connected downstream thereof.

A device for refrigerating and/or liquefying a working gas comprising helium, the device comprising a looped working circuit for the working gas includes, in series, a compression station, a cold box, a heat exchange system exchanging heat between the cooled working gas and a user, the device further comprising an additional pre-cooling system comprising at least one tank of auxiliary cryogenic fluid, such as liquid nitrogen, the cold box comprising a first cooling stage of the working gas comprising a first exchanger disposed at the output of the compression station as well as a second heat exchanger and a third heat exchanger, the first heat exchanger being of the aluminum plate-fin type, the second heat exchanger being of the tube or welded plate type, characterized in that the second and third heat exchangers are connected both serially and in parallel on the working circuit downstream of the first heat exchanger.