Abstract: A method of obtaining refrigeration at a cryogenic level comprising a gaseous fluid fed in the form of an incoming stream to sustain a refrigerative load. The incoming stream is stepwise cooled and expanded with liquefaction. The liquid fluid formed is used to sustain a refrigerative load, evaporating as a consequence, and the vapour constitutes a return stream which is adiabatically compressed so as to attain a temperature close to the temperature of the incoming stream before the liquefaction thereof.

Abstract: A method of producing supercold temperature in cryogenic systems by compressing a gaseous fluid constituting an incoming stream followed by its stepwise cooling by a return stream of the fluid. The incoming stream is split into a main stream and a subsidiary stream which is used to compensate for the losses in the system on being expanded with the removal of energy. The main stream is expanded and liquefied in a liquefaction stage. At least a portion of the subsidiary stream, on being expanded with the removal of energy, is introduced into the liquefaction stage, liquefied therein and used to sustain a refrigerative load. After that, the liquid fluid formed is used to sustain the refrigerative load and is evaporated as a consequence. The vapor forms the return stream which is passed through the cooling stages and the liquefaction stage in the reverse direction.

Abstract: A screen heat exchanger intended to cool or heat various fluid media in different branches of industry. The exchanger comprises alternating screens and spacers rigidly connected into a bank; the spacers have holes for the passage of the fluid medium. The screens are made of a sheet material whose heat conduction is higher than that of the material of the spacers. The screen elements forming the meshes are inclined to the plane of the screen.