Abstract: According to the invention, a metal workpiece made by additive manufacturing is subjected, following the additive manufacturing process, to a cold treatment in which the workpiece is cooled to a lower target temperature of less than minus 30° C. in a cooling phase and is then heated up to an upper target temperature in a heating phase. The cold treatment significantly improves the properties of the workpiece in respect of the mechanical quality thereof.

Abstract: A cooling system using carbon dioxide as a coolant comprises a cooling chamber for storing products to be cooled during transport and a cooling unit for cooling the atmosphere in the cooling chamber. The cooling chamber and the cooling unit are mounted on or integrated in a cooling vehicle like a truck, a railway wagon or a ship. The cooling unit comprises a carbon dioxide storage compartment and at least one cooling channel through which air is led from and to the cooling chamber. The carbon dioxide storage compartment and the cooling channel are separated from each other by a thermal well-conducting but gas-tight plate serving as a heat exchanger between the carbon dioxide in the carbon dioxide storage compartment and the air in the cooling channel.

Abstract: Apparatus for transmitting electrical energy with a superconducting current carrier, in which the superconducting current carrier to be cooled is accommodated in a first cooling channel, which first cooling channel is connected by way of a coolant feed line to a supply device for a first cooling medium and is surrounded by at least one second cooling channel, for conducting through a second cooling medium, which is flow-connected to a coolant-discharge line for heated second cooling medium, wherein a supercooled, liquefied gas is used as the first cooling medium, is characterized according to the invention in that a liquefied gas is used as the second cooling medium and the second cooling channel is equipped with means for removing a gas phase occurring due to evaporation of the second cooling medium.

Abstract: The invention relates to a method for additive manufacture of a workpiece under protective gas, wherein a workpiece is assembled from a sequence of workpiece contours, each of which is manufactured by selective sintering or melting of a powdery or wire-like material by applying an energy beam thereto, wherein a workpiece contour is manufactured under the effect of a protective gas consisting of carbon dioxide and an inert gas. According to the invention, the chemical composition of each workpiece contour is modified according to a specified program by variation of the composition of the protective gas. Heat treatment occurring after manufacture of the workpiece contour provides for defined mechanical and technological quality values of the workpiece contour. A workpiece having zones with defined mechanical and technological quality values is produced in this manner.

Abstract: The invention relates to a device for generating and storing carbon dioxid snow, comprising a container into which an expansion nozzle connected to a supply line for liquid carbon dioxide and a gas extraction line open, a removal device for removing carbon dioxide snow out of the container, and a measuring device for detecting the fill level of the carbon dioxide snow in the container. According to the invention, the measuring device comprises a photoelectric sensor unit which is arranged at a vertical distance to the base of the container and which comprises a light-emitting transmitter and a light-sensitive receiver.

Abstract: In a process for preparing nitric acid, nitrogen oxides are first produced in an ammonia combustion plant and cooled in a condenser to form a nitric acid-containing solution. The nitric acid-containing solution is then supplied to at least one absorption tower in which the nitrogen oxides are brought into contact with water and oxygen, wherein the nitrogen-containing gas mixture reacts with the water and the oxygen at least in part to form an aqueous nitric acid-containing solution which accumulates at the base of the absorption tower and is then compressed and recycled via a conduit back into the absorption tower. In order to minimize the concentration of nitrogen oxides in the offgas from such a plant and to increase the efficiency of the process, the invention proposes injecting ozone into a connection conduit which leads from the condenser to a first absorption tower and conducts the nitric acid-containing solution.

Abstract: A method for producing ultra-pure hydrogen is provided which includes heating water for stripping argon from the water; and separating the argon-stripped water into an oxygen stream and a hydrogen stream, wherein the hydrogen stream includes an ultra-pure hydrogen stream. A related system for producing an ultra-pure hydrogen stream is also provided which includes a container in which argon is stripped from water by steam; at least one electrolyzer cell to be contacted by the argon-stripped water; wherein the at least one electrolyzer cell provides an oxygen stream and a hydrogen stream with an argon content less than 0.25 ppm.

Abstract: In order to meter carbon dioxide snow, a storage container has an output unit, which comprises: an output opening, which is arranged laterally in the bottom region of the storage container; and a horizontally movable sliding element, which cooperates with the output opening. In order to fill the storage container with carbon dioxide snow, at least two snow horns are provided on the storage container, in which snow horns liquid carbon dioxide is converted into a mixture of carbon dioxide snow and carbon dioxide gas. The mouth openings of the snow horns point toward each other at least in one direction component so that the material flows exiting therefrom are directed at least partially toward each other. This facilitates the separation of snow and gas and increase the efficiency of the device.

Abstract: For the transmission of electrical current, determined superconducting current carriers are accommodated in a cryostat, in which they are cooled with an undercooled cryogenic cooling medium, e.g. liquid nitrogen. The current carrier is electrically connected at the ends thereof to two normally conducting current supply means. The cooling medium is undercooled from a storage container to a temperature below its boiling temperature and supplied to the cryostat via a cooling medium inlet, brought into thermal contact with the superconducting current carrier, and subsequently discharged via a cooling medium outlet of the cryostat. According to the invention, the cooling medium from the cryostat is to be used for cooling at least one of the normally conducting current supply means.

Abstract: The present invention relates to the transport of products in a desired conservation temperature range, comprising: a box (2) made of insulating material delimiting a compartment opened upwards having a volume less than 150 liters and able to contain products, the box (2) having a determined heat dissipation value; a cover (4) made of insulating material adaptable on the box (2) to seal the compartment; a diffusing divider wall (5) interposed between the box (2) and the cover (4) to delimit with the cover (4), a chamber with a surface (7) for receiving at least one refrigerated load (6) emitting a heat value, the cover (4) and the divider wall (5) comprising complementary means for locking/unlocking (9) with one another; characterized in that the heat energy emitted by the refrigerated load (6) and the thermal diffusion coefficient of the divider wall (5) are adjusted such that, at determined transport and conservation temperatures and for a desired duration after receiving the refrigerated load (6) and

Abstract: In order to separate diborane from a gas mixture containing diborane and hydrogen, the gas mixture is normally cooled in a storage tank using liquid nitrogen, wherein the diborane freezes out. In order to enable an extensively continuous separation of the diborane from the gas mixture, according to the invention, the gas mixture is brought into thermal contact with a liquefied gas in a heat exchanger, which liquefied gas is held at a pressure such that the diborane is liquefied by the thermal contact with the coolant, and the liquefied diborane is then discharged from the first heat exchanger and supplied to a storage tank. In a downstream, second heat exchanger, the diborane remaining in the gas mixture can then be caused to freeze out.

Abstract: In a tank filling process for filling a refrigerant tank of a vehicle with a cryogenic refrigerant, firstly a liquefied cryogenic refrigerant stored at a pressure p1 in a storage tank is supplied to a conditioning vessel, subsequently the flow connection between storage tank and conditioning vessel is interrupted, and the pressure in the conditioning vessel is increased, for example by virtue of a flow connection to a pressure build-up vessel being produced, to a pressure p2, wherein p2>p1, whereby the liquefied refrigerant is present in the conditioning vessel in the supercooled state. Subsequently, the supercooled, liquefied refrigerant is supplied to the tank to be filled. By means of the device according to the invention and the process according to the invention, evaporation losses during the filling process can be substantially avoided.