Continuous production of products from a melt, comprises supplying melting raw materials or a premelt into a skull crucible, and heating the melt in the skull crucible at a predetermined temperature using high-frequency alternating field

摘要

The method for continuous production of products from a melt, comprises supplying melting raw materials or a premelt into a skull crucible, heating the melt in the skull crucible at a predetermined temperature using high-frequency alternating field, and continuously discharging the melt heated at the predetermined temperature. A wall of the skull crucible comprises or forms an electrically conductive inductor and a base made of electrically non-conductive but thermally conductive material, where the electrical conductivity of the base is less than 10 -8S/m. The method for continuous production of products from a melt, comprises supplying melting raw materials or a premelt into a skull crucible, heating the melt in the skull crucible at a predetermined temperature using high-frequency alternating field, and continuously discharging the melt heated at the predetermined temperature. A wall of the skull crucible comprises or forms an electrically conductive inductor and a base made of electrically non-conductive but thermally conductive material, where the electrical conductivity of the base is less than 10 -8S/m and the coefficient of thermal conductivity is less than 2 mole%. The material is nitride ceramic, which contains an oxygen content of less than 2 mole%. The wall and the base are cooled, so that a skull layer forms itself in the interior of the crucible. The wall of the skull crucible simultaneously comprises the coil for the application of the high-frequency alternating field. The skull crucible is operated for two months in continuous operation. The wall forms a single-coiled inductor, with which the high-frequency alternating field is generated. The inductor is operated with an alternating current at a frequency of 90 kHz, where 40% of electrical input power is introduced as heat output into the melt. The skull crucible is operated at a voltage of 400-600 V. A borate-containing glass is melted or purified, in which a temperature interval of 500[deg] C lies between the viscosity values of 10(7.6) dPa.s and 10 3dPa.s. The borate-containing glass contains metal oxide as component, whose metal ions are two- or high-order. The ratio of the molar material quantities of silicon dioxide to borate in the melting product is = 0.5. The melt is continuously discharged by ceramic or noble metal tube, which is connected at the bottom of the crucible. The melt is continuously discharged by the electrically conducting wall of the skull crucible. Independent claims are included for: (1) a device for continuous production of products from a me and (2) a skull crucible.