Abstract: The invention relates to a solar concentrator comprising a solid body consisting of a transparent material that has a light coupling surface and a light decoupling surface, the solid body having a light guide part that tapers towards the light decoupling surface, being located between the light coupling surface and the light decoupling surface and being delimited by a light guide surface between the light coupling surface and the light decoupling surface, the light guide surface merging into the light decoupling surface with a constant first derivation. The invention also relates to a method for the production of a solar concentrator, wherein the transparent material is precision-moulded between the moulds.

Abstract: A method of producing a quartz glass crucible by arc melting a quartz powder molded product loaded on the inner side of a mold while performing vacuum suction, includes initiating the melting of quartz powder from the rim edge of a quartz powder molded product, subsequently lowering the arc electrode or raising the mold to heat and melt the sections on the downside of the rim edge. The method is preferably carried out such that the inner surface of the crucible is sealed within a time corresponding to 10% of the total arc time starting from the initiation of arc melting, and the seal thickness is 3 mm or less. The quartz glass crucible thus produced is useful for the pulling up of silicon single crystals and has a uniform glass layer with fewer internal bubbles.

Abstract: Processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 109 poises, preheating molds at a temperature at which the glass material has a viscosity of from 109 to 1012 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20° C.

Abstract: Processes are disclosed for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 10.sup.9 poises, preheating molds at a temperature at which the glass material has a viscosity of from 10.sup.9 to 10.sup.12 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20.degree. C.

Abstract: Method and apparatus for producing vitreous optical elements by injection molding, which essentially includes the stages of: melting down a glass material into a molten state in a viscosity at or lower than a working point of the glass material; injecting molten glass under pressure into a mold cavity defined between transfer surfaces of relatively movable mold members of a mold assembly unit in communication with a sprue connecting the mold cavity with an injection port on the outer side of the mold assembly unit; and applying a predetermined pressure on the glass material in the mold cavity while cooling the mold assembly unit down to a temperature in the vicinity of yielding point of the glass material.

Abstract: Processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 10.sup.9 poises, preheating molds at a temperature at which the glass material has a viscosity of from 10.sup.9 to 10.sup.12 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20.degree. C.

Abstract: A method and device for enabling a molten radioactive glass to be cast from a crucible (2) situated in a top cell (1) and a container (4) situated beneath said crucible in a bottom cell (3), the radioactive glass flowing vertically downwards along a casting axis through an opening provided in a concrete slab (5) which separates said cells, said device being characterized in that it comprises the following components in succession going downwardly: a deformable guide tube (11) constituted by two housings (14, 15) slidably mounted in each other, with the inner walls (20, 21) thereof being frusto-conical in shape, and the apex of said frusto-conical shape being situated beneath said guide tube, the top housing (14) being fixed beneath said concrete slab, the bottom housing (15) having an end wall (22) in the form of a portion of a sphere, and said two housings being interconnected by a metal bellows (23); and a moving tube (12) constituted by an enclosure (32) whose inside wall extends downwardly so as to be cap

Abstract: The invention is directed to a method of filling an evacuated metal vessel ith a radioactive glass melt from a glass melting furnace. The metal vessel is equipped with a suction tube mounted at the bottom of the vessel. The steps of filling and sealing the metal vessel are carried out faster and with the furnace atmosphere properly sealed off. For this purpose the vessel is placed in a holding device which is positioned over a closable suction port of the glass melting furnace. The suction port is hermetically sealed off from the atmosphere of the cell and is then opened. The vessel is lowered vertically until the suction tube dips into the glass melt. After the vessel has been filled, the glass in the suction tube is frozen thereby forming a plug. The vessel is moved upwardly in the vertical direction until the suction tube is drawn out of the furnace. The suction port is closed and a sealing cover for the vessel is put into position over the port.

Abstract: Suction molds used in the suction removal process must first be prepared ore they can receive vitrified radioactive waste materials. A method is disclosed for preparing the suction mold which includes a suction pipe welded into the base of the mold with a desired-break location whereat the suction pipe is broken off during the suction removal process. An evacuation stub is mounted in the mouth of the suction pipe and communicates with the interior of the mold. The method of the invention includes evacuating the mold through the evacuation stub and then heating the mold to remove moisture and organic impurities. The mold is then filled with a dry inert gas and the evacuation stub is cleaned. The mold is then evacuated to a predetermined residual pressure. Thereafter, the evacuation stub is cold-press welded so as to close off the interior of the mold from the ambient.

Abstract: The invention is directed to a method of filling an evacuated metal vessel ith a radioactive glass melt from a glass melting furnace. The metal vessel is equipped with a suction tube mounted at the bottom of the vessel. The steps of filling and sealing the metal vessel are carried out faster and with the furnace atmosphere properly sealed off. For this purpose the vessel is placed in a holding device which is positioned over a closable suction port of the glass melting furnace. The suction port is hermetically sealed off from the atmosphere of the cell and is then opened. The vessel is lowered vertically until the suction tube dips into the glass melt. After the vessel has been filled, the glass in the suction tube is frozen thereby forming a plug. The vessel is moved upwardly in the vertical direction until the suction tube is drawn out of the furnace. The suction port is closed and a sealing cover for the vessel is put into position over the port.

Abstract: A parison is molded from a gob of molten glass by first increasing the volume of the interior of a cup-shaped main mold body by an extra volume. Then the molten-glass gob is inserted through an upper opening into the interior of the main mold body. A neck mold comprising a split neck ring is closed on the main mold body so that the neck mold and the main mold body together define a mold cavity partly formed by the interior of the main mold body. A plunger is inserted through the neck mold down into the gob in the mold cavity to displace molten glass and shape the gob into a parison. The extra volume of the interior of the main mold body is then decreased to zero at the latest until the time at which the parison is finished, so that the molten glass rises in the mold cavity up to a level above the top of the main mold body. Finally the parison thus formed is demolded.

Abstract: A device for disposing of a contaminated suction tube connected to a storage container for glass-enclosed radioactive waste material by inserting the tube in the container for ultimate disposal with the container. The device consists of a metal sleeve that is mounted on the bottom wall of the container and extends upwardly into the container and an inner tube which slides in the sleeve. The suction tube is connected to the lower end of the inner tube. Detachable connecting means, such as solder, fixes the inner tube and hence the suction tube to the sleeve until the glass filling operation is over. At this point the solder melts and the suction tube and inner tube are free to be inserted into the container by sliding the inner tube upwardly in the sleeve.

Abstract: A method and apparatus for encapsulating or embedding highly radioactive waste in glass within an ultimate storage container in which molten glass is transferred from a melting furnace to the container by means of suction. The container is evacuated, and a sealed suction tube connecting to the container is immersed in the molten glass containing the waste, whereupon the seal is broken and the molten glass flows under the force of atmospheric pressure into the container. The operation may be carried out by remote controls.

Abstract: Molding of hollow glass articles wherein a gob flows from a feeder into a mold and forms a hollow tube as it enters the mold, and a pressure differential is applied across the tube so that the tube is shaped in the mold to form the hollow article. During application of the pressure differential, deformation of the glass between the feeder and mold, is prevented by proximately positioning of the feeder and mold. This pressure differential is obtained by applying vacuum between the mold and molten tube.

Abstract: Molding of hollow glass articles wherein a gob flows from a feeder into a mold and forms a hollow tube as it enters the mold, and a pressure differential is applied across the tube so that the tube is shaped in the mold to form the hollow article. During application of the pressure differential, deformation of the glass between the feeder and mold, is prevented by proximately positioning of the feeder and mold.