The invention relates to an apparatus for introducing dry ice pellets into fresh meat, comprising a housing (2), in which at least one injection device (3, 4, 5, 6) for introducing dry ice pellets (27) is arranged, and guide channels (11a, 11b, 12a, 12b), which lead to a front face (15) of the housing, for axially movably guiding a penetration needle (8, 9), which is tapered at the distal end thereof, and a drive device for axially moving the penetration needle (8, 9). A loading unit (25) can be inserted between a rear portion (13) and a front portion (14) of the housing (2), which loading unit is provided with a number of feedthroughs (26a, 26b), which can be equipped with dry ice pellets (27) and which can be brought into a position in alignment with the guide channels (11a, 11b, 12a, 12b). During operation of the apparatus, penetration channels are first produced, by means of the penetration needles (8, 9), in a piece of meat to be cooled, into which penetration channels the dry ice pellets (27) are subsequently introduced from the feedthroughs (26a, 26b) of the loading unit, also using the penetration needles (8, 9). The feedthrough enables efficient introduction of dry ice pellets into a piece of meat.
The invention relates to a device for producing dry ice pellets comprising a pressing cylinder, into which an inlet opening for feeding liquid carbon dioxide leads and which is equipped, at an end, with a die, which has one or more openings, and with a piston, which is longitudinally movably accommodated in the pressing cylinder. During use, liquid carbon dioxide is fed to the pressing cylinder. Said carbon dioxide is expanded at the inlet opening, is at least partially converted into carbon dioxide snow and is pressed against and through the die by the movement of the piston. According to the invention, the die is in the form of a cylindrical body that can be connected to the pressing cylinder and is equipped with feed-throughs, which are oriented parallel to a longitudinal axis of the die and are dimensioned in such a way that the length and the diameters of the feed-throughs correspond to the length and the diameters of the dry ice pellets to be produced.
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 increases the efficiency of the device.
When welding with a consumable wire electrode, current contacting occurs when the electrode wire passes by a readily electrically conductive contact element. In order to improve the current contacting and reduce the wear of the contact element in particular, the invention proposes subjecting contact elements to a cold treatment prior to using same. The cold treatment has a cooling phase during which the temperature of the contact element is reduced to a lower target temperature, a subsequent holding phase in which the contact element is substantially held at the target temperature, and a final heating phase, in which the contact element is brought to an upper target temperature. The use of contact elements treated using the method according to the invention leads to a substantial increase of the wear resistance compared to untreated contact elements.
In a method for manufacturing metallic components by means of generative production, a layer of metal powder is selectively melted or sintered by being exposed to an energy beam in an evacuated radiation chamber. When the radiation chamber is subsequently flooded with a cooling gas, the melted or sintered part solidifies to form a solid contour. Instead of the previously common practice of using helium, which is expensive and not readily available, as the cooling gas, it is proposed according to the invention to use a gas that contains hydrogen. Hydrogen has a higher thermal conductivity than helium and does not impair the surface of the workpiece, or only to a negligible extent.
According to the prior art, a super-cooled liquid medium, for example a super-cooled liquid nitrogen, is pumped through a sub-cooler and is thereby cooled by the same medium that evaporates in the vacuum. This super-cooled nitrogen is then used as a coolant for a consumer. If only a small amount of heat is emiited by the consumer to the nitrogen, the liquid medium can be guided in the circuit, in which the sub-cooler is arranged. For compensating volume fluctuations, such a circuit requires a compensation vessel which, however, is very expensive and can furthermore only be operated in the presence of a super-cooled medium when either a part of the medium is heated using external energy, or an inert gas which boils at very low temperatures has to be used as a pressure compensation medium. According to the invention, it is proposed that the supply container for the liquid medium is integrated into the cooling circuit and is used as a compensation vessel. As a result, the use of a separate compensation vessel can be dispensed with.