Abstract: The present invention provides devices for glass melt devlivery and methods for using these devices. In these devices, a delivery nozzle comprising at least one platinum group metal material is directly heated by electricty. To facilitate heating, a cylindrical heating ring is mounted in ceramic base. The device's construction ensures a regulatable heating of the nozzle and the melted glass flux.

Abstract: The invention relates to a device for the production of a glass melt from a batch; with a melt tank (1) that has peripheral walls (1.1-1.4) and a bottom (1.5); with a discharge channel (2) which is located under the bottom (1.5) of the melt tank (1) and which is in conducting connection with the melt bath (3) over an entry opening (2.3) and has an outlet opening (2.4) for the finished melt in the zone of a peripheral wall (1.1) of the melt tank (1); with at least one heating arrangement for the heating of the melt bath (3); the entry opening (2.3) of the discharge channel (2) is arranged in a central zone of the bottom (1.5) of the melt tank (1); the discharge channel (2) has a covering (2.2) which is located at least approximately at the level of the bottom (1.5) of the melt tank (1).

Abstract: The invention relates to a device for the production of a glass melt from a mixture; with a melt tank (1) that has peripheral walls (1.1-1.4) and a bottom (1.5); with a discharge channel (2) which is located under the bottom (1.5) of the melt tank (1) and which is in conducting connection with the melt bath (3) over an entry opening (2.3) and has an outlet opening (2.4) for the finished melt in the zone of a peripheral wall (1.1) of the melt tank (1); with at least one heating arrangement for the heating of the melt bath (3); the entry opening (2.3) of the discharge channel (2) is arranged in a central zone of the bottom (1.5) of the melt tank (1); the discharge channel (2) has a covering (2.2) which is located at least approximately at the level of the bottom (1.5) of the melt tank (1).

Abstract: In the manufacturing of high melting point glasses with volatile components, in particular of glasses from the group of boron glasses and borosilicate glasses, a furnace is provided that has a superstructure, fossil fuel burners, and a melting tank. In front of a conditioning zone and a throat leading to an extraction zone, a step-shaped raised area in the bottom is provided which is formed continuously over the complete width of the melting tank. In order to suppress segregation or, respectively, phase separation, to protect the furnace construction materials and to enable problem-free operation, a temperature of at least 1600.degree. C.

Abstract: A melting furnace for thermal treatment of heavy metal-containing and/or dioxin-containing special wastes, including a clog preventing system including a principal furnace vessel, which exhibits a melting tank for holding a melt; at least one feeder for feeding the material to be treated; a discharge chamber, which is at a spatial distance from the feeder, the feeder being connected gas-tight via a siphon to the melting tank; the principal furnace vessel and the discharge chamber having third heating elements in the form of bath electrodes, by means of which an electric current can be run through the melt and the siphon for additional heating of the melt.

Abstract: A waste vitrification apparatus (10) having rotatable mixer impeller (16) functioning as a shaft electrode (60) and metallic vessel (14) functioning as a vessel electrode (62). A stream (12) of waste material and vitrifiable material are mixed and melted in the vessel (14) for vitrification. The waste vitrification method converts a feed stream (12) by mixing the feed stream into a glass melt (13) and melting glass batch of the feed stream (12) to form a foamy mass. The stream is dispersed by the impeller (16) to form a foam which is then densified in a settling zone (22), recovered through a spout (24) and solidified in storage containers. An adjuster adjusts the location of the mixing impeller (16) in the vessel (14) to change the depth of the settling zone (22). The impeller (16) is mounted on a drive shaft (18) having a recirculating coolant flow.

Abstract: Furnace for the continuous melting of mixtures of oxides by direct induction at high frequency and a very short refining time and with a low energy consumption, comprising an intake (14) and a nozzle (15) for the continuous discharge of oxides into a metal crucible (3) having cold walls heated by a high frequency coil (5), characterized in that the height of the oxide bath is between 2 cm and 20% of the diameter of the metal crucible and in that the furnace hearth (4) is both transparent to the inducing magnetic field and sufficiently cooled to ensure the formation and maintenance of a protective solid crust at the bottom of the crucible.

Abstract: An apparatus for processing various hazardous waste materials by melting in a vessel for subsequent solidification is disclosed which includes a seal for the cover thereof. Melter includes a high-speed mixing impeller powered by a drive shaft which extends through an opening in the cover. The vessel is electrically heated by discharge of electrical energy through the melt contained in the vessel. In one embodiment the impeller and shaft are included in the electrical heating circuit. A shaft seal engages the shaft at a point spaced from the cover. An axially extensible seal seals a space bounded by the shaft seal and the opening in the cover. Purge gas is supplied to the sealed space to provide positive gas flow from the sealed space into the vessel. A cold wall transport duct for off-gas porting is disclosed. A bottom drain structure including a sleeve and plug is also disclosed. The output of the melter may be subsequently heated in a holding tank to refine the output.

Abstract: A melting furnace for treating wastes is provided which has a container equipped with a feed port for a glass raw material and wastes to be treated at the top thereof and a discharge port for molten glass containing said wastes at the bottom thereof, the container having a wall made of a heat resistant alloy and the container wall being in contact with molten glass inside the container; a heating electrode disposed in the container, the container wall acting as a counter electrode for the heating electrode; and a cooling system disposed at the back side of the container wall. By directly supplying electric power to the glass means disposed at the back side of the container wall.By directly supplying electric power to the glass between the container wall and the heating electrode, the molten glass containing the wastes can be formed. By conducting cooling of the container wall by the cooling system, corrosion of the wall due to the atmosphere in the container can be restricted.

Abstract: A method for thermal decomposition treatment of a radioactive waste uses an apparatus comprising a container for holding molten matter of a radioactive waste containing a sodium compound, a pair of electrodes contacting the molten matter, and a power source for applying voltage between the electrodes while changing the polarity thereof every several tens of seconds. In this apparatus, the molten matter can be heated in the container by Joule heat, which is evolved by electric current directly flowed through the molten matter, so that the sodium compound contained in the radioactive waste can be decomposed, vaporized and removed to recover a stabilized radioactive solid as a residue in the container.

Abstract: A melting furnace is disclosed which heats by joule effect to supply molten material of uniform temperature at the floor of the melter. During formation of molten material, an essentially isothermal condition across a given horizontal plane of the body of molten material is established. Spaced apart opposed electrodes and controlled current flow establish these uniform temperatures and allow molten material to be formed directly from the melter without further processing.

Abstract: The joule melter has an outer cylindrical electrode which forms the outer wall of the melt containment, an inner cylindrical electrode which protrudes upward in the containment and forms the outlet for the melt, thus, also determining the depth of the melt. A non-conducting sealing material forms a base plug between the electrodes. A cylindrical electrically conductive baffle is located between the electrodes and includes an opening which allows the melt to flow from near the outer electrode where the melt material is first inserted into the melter, to the inner electrode which is the outlet. In addition to the inner and outer electrodes, the baffle may be connected to a power supply to modify the currents flowing at each of the electrodes.

Abstract: A method for tapping a furnace contains a tappable melt of silicon dioxide to be reduced to silicon with carbon, which comprises providing a graphite tap pipe on the furnace, and electrically heating the tap pipe to cause liquid silicon to flow out of the pipe, and a device for carrying out the method.

Abstract: A furnace for the melting of glass in which horizontally spaced regions of the molten glass body are heated by passage of alternating electric current between diagonally opposed electrodes of two groups and supplied from a primary power supply circuit, and in an intervening zone above a withdrawal path leading to an outlet auxiliary electrodes spaced apart longitudinally of the zone are fed with current from an auxiliary supply circuit including regulators providing for adjustment of the heating effect along different parts of the zone to set up a convective effect balancing any downward pull which could draw unrefined glass or batch material into the withdrawal path.

Abstract: A high temperature electronic furnace wherein a product-containing vessel has a product exit orifice, a plurality of electrodes are located in the vessel to define primary current paths adjacent the orifice, a control electrode is positioned in the vessel for defining an additional current path adjacent the orifice and a circuit for energizing the primary electrodes with multiphase current and for time-sharing the multiphase current with the control electrode. The degree of time-sharing is made responsive to the temperature of product passing through the orifice and/or the rate of flow of product passing through the orifice. In addition, the control electrode is moveably positioned with respect to the orifice, with the position of the control electrode being dependent upon the temperature of product passing through the orifice and/or the rate of flow of product through the orifice.

Abstract: A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members.The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace.