Abstract:
A method for melting inorganic materials, preferably glasses and glass-ceramics, in a melting unit with cooled walls is provided. The method includes selecting the temperature of at least one region of the melt is selected in such a way as to be in a range from Teff−20% to Teff+20%, where the temperature Teff is given by the temperature at which the energy consumption per unit weight of the material to be melted is at a minimum, with the throughput having been selected in such a way as to be suitably adapted to the required residence time.
Abstract:
The invention relates to a method and a device for producing colored glasses. The aim of the invention is to obtain a paricularly intimate mixture and to enable a quick change of the melt at the same time. To this end, the following procedure steps are applied: a melt made of a compound or fragments of glass is produced, the glass melt is further processed in at least one additional vessel, the melt is supplied to a skull device (3) (skull pot or skull channel) during subsequent processing, a dye is supplied (6, 6.1) to the melt after the melt was in the melting station (1) but before the melt enters the skull device (3) or while said melt is in the skull device.
Abstract:
A process for producing a borate-containing, low-alkali material is provided. The process includes induction-heating a boron-containing melting material directly in an appliance using an alternating electromagnetic field. The, melting material as a constituent includes at least one metal oxide, the metal ions of which have a valency of at least two, in a quantitative proportion of at least 25 mol %, and in which the ratio of the molar substance quantities of silicon dioxide to borate in the melting material is less than or equal to 0.5.
Abstract:
This invention relates to a device and a process for introducing gases into a hot medium, whereby device (1) contains a pipe (2) for introducing gas and a cooling jacket (3) that encases pipe (2).
Abstract:
The invention describes a method for refining molten glass materials, in which refining gas is generated by refining agents in the molten glass, and in which the molten glass is heated to a temperature of between 1650° C. and 2800° C., and the maximum release of refining gas by the refining agents takes place at over 1500° C.
Abstract:
According to the invention, the skull pot is provided with the following characteristics: a pot wall (1), a bottom (3) and an induction coil (9) which surrounds the pot wall (1) and by means of which high-frequency energy can be coupled into the contents of the pot. The pot wall (1) is made of a ring of metal pipes (1.1) which can be connected to a cooling medium. Slits are embodied between adjacent metal pipes (1.1). The metal pipes (1.1) are bent at a right angle at the upper ends thereof in such a way that said pipes extend towards the outside, when the pot wall (1) is viewed from above, and form a collar (2). The collar (2) is surrounded by an additional wall (upper wall 4). The upper edge of said wall is situated on a higher level than the collar (2) in such a way that the melt covers the collar (2) during operation.
Abstract:
Hard glass fire retardant glasses can be tempered in a conventional air tempering plant having heat transmission values of approximately 200-500 W/(m.sup.2 .times.K) yielding in the tempered state a fire resistance period of at least 30 minutes according to DIN 4102 and the safety properties according to DIN 1249 (safe break). In order to achieve the combination of fire resistance period and safety properties, the glasses must have a coefficient of thermal expansion .alpha..sub.20/300 of between 3 and 6.times.10.sup.-6 K.sup.-1, a specific thermal stress .psi. of between 0.3 and 0.5N/(mm.sup.2 .times.K) , a glass transitione temperature Tg of between 535.degree. and 850.degree. C., a product of specific thermal stress .psi. multiplied by (Tg -20.degree. C.) of between 180 and 360N/mm.sup.2, an upper annealing temperature (temperature at a viscosity of 10.sup.13 dPas) of over 560.degree. C., a softening temperature (temperature at a viscosity of 10.sup.7.6 dPas) of over 830.degree. C. and a working temperature (temperature at a viscosity of 10.sup.4 dPas) of below 1300.degree. C.
Abstract:
For ion exchange at the surface of glass or glass ceramic, the ion exchange is carried out by means of a solid layer containing mainly one or more salts which do not melt at the exchange temperature and contain mono- or divalent cations. The layer can be applied to the glass as a dispersion in water or as an organic dispersion medium. Preferably, its thickness is 0.02 to 2 mm and the salts have a particle size of less than 60 .mu.m. Despite the solid reaction, the ion exchange proceeds at a surprisingly rapid rate and leads to products having highly reproducible properties. Corrosive attack of the glass surface does not take place.
Abstract:
A process for the manufacture of porous sintered bodies with large open pore volume and defined pore diameter. A sinterable material in the form of finely ground powder is mixed with a leachable substance. The leachable substance is in the form of powder of a defined particle size. The mixture of sinterable material and leachable substance is heated to the sintering temperature and maintained there until the sinterable mass is sintered. The mass is then cooled and the leachable substance leached from the sintered mass.
Abstract:
A device for the refining of a glass melt at high temperatures according to the skull pot principle is provided. The device includes a skull crucible having walls that are constructed from a plurality of pipes, a high-frequency coil for coupling electrical energy into the contents of the skull crucible, and an inlet and an outlet of the skull crucible being arranged in a melt surface region of the glass melt, wherein the inlet and the outlet are essentially arranged lying opposite one another.