Abstract: In a glass melting furnace, a radiation screen wall is installed between a melting area and a refining area with a refining bank. This radiation screen wall leaves a flow path above the melt surface of the glass bath for the return flow of at least part of the combustion gases from the refining area to the melting area. In order to suppress a return flow of already refined and very hot glass melt from the refining area into a melting area, but still allow the charging material to melt completely as early as possible, the furnace is operated to produce at least one upward current between the middle of the melting area and the front face of the refining bank in the glass melt.

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 method of operating a regenerative glass melting furnace with end-firing or cross-firing utilizes burners to provide sub-stoichiometric combustion and super-stoichiometric combustion along the sidewalls or transverse walls of the furnace and equipment associated with the method. Fuel supply is controlled so that overall combustion is stoichiometric.

Abstract: An electrically heated tank furnace is used to melt glass whereby a floating gall layer is formed on the melt, in particular during the vitrification of hazardous materials such as asbestos, fly ash, filter dust, whereby the tank of the furnace is fitted with a discharge outlet for the melt and an overflow channel with an inlet for the gall. A stream of ascending gas bubbles is produced in the melt. In order to promote better and automatic draining of the gall the stream of gas bubbles is produced directly in front of the overflow channel which thereby maintains a layer of liquid gall in the overflow channel and a layer of molten glass retained by a weir on the bottom of the overflow channel. The temperature in the overflow channel is chosen to be above the melting temperature of the gall, whilst the bottom layer of glass is maintained at a temperature at which the viscosity of the glass is so high that the glass does not drain out the overflow channel.

Abstract: At least one cooling zone and a subsequent homogenization zone are installed between the inlet and the outlet of a forehearth for conditioning and homogenizing a stream of colored glass. The glass temperature in the forehearth is reduced from the inlet temperature T1 to an outlet temperature T2. In order to increase the cooling effect while simultaneously homogenizing the glass temperature at a throughput of at least 70 tons per day, a raised area is installed in the bottom along the length of the cooling zones to set a maximum bath depth Dmax of 120 mm. Furthermore, the cooling capacity is such that the temperature 20 mm above the bottom is reduced by at least 40.degree. C. in the cooling zone. In the apparatus used, the raised area above the bottom covers the complete length of the cooling zones K. The maximum depth Dmax of the glass bath is 120 mm above the raised area and in the homogenization zone the channel is at least 30 mm deeper.

Abstract: A continuously flowing glass stream is conditioned and homogenized along a conditioning stretch, which extends from an entry side to at least one extraction point, and at the beginning of which there is a cooling zone, to which at least one homogenizing zone for the glass temperature is connected. In the working end or the distribution channel the temperature is reduced from the entry temperature T1 to an outlet temperature T2. In order to achieve the necessary conditioning and homogenization, even at high throughputs, the glass stream in the at least one cooling zone of the working end or distribution channel has a cross section with a depth/width ratio D/W of a maximum 0.6, or 0.5, or 0.4, or 0.3 or 0.

Abstract: An electrode assembly for glass tank furnaces comprises a rod electrode inserted in a cylindrical electrode holder, through which it can be advanced. Along at least part of its length the said electrode holder is fitted with a device for forced cooling and is installed in an electrode block in the furnace. In order to dispense with and in order to operate the electrode holder at a constant temperature the holder is inserted with the bottom face below a filling level determined by the design of the furnace, and provided with a seal between it and the electrode above the filling level. Preferably the electrode holder has an outer tube and an inner tube, which create an annular gap between them for a cooling medium, whereby the inner tube protrudes out of the upper end of the outer tube and a sealing unit is provided between the inner tube and the electrode.

Abstract: A continuously flowing glass stream is conditioned and homogenized along a conditioning stretch, which extends from an entry side to at least one extraction point, and at the beginning of which there is a cooling zone, to which a homogenizing zone for the glass temperature is connected. This method is preferentially used for the manufacture of molded glass articles, such as containers and pressed articles. In order to achieve the necessary conditioning and homogenization, even at high throughputs, the glass stream in the cooling zone has a cross section with a depth/width ratio D/W of a maximum 0.6 or 0.5, or 0.4, or 0.3, or 0.

Abstract: In a glass melting furnace, a combination includes a tank having an end chamber for containing a glass melt, the tank having soldier blocks arranged side-by-side which are of a refractory, mineral material and form a wall of the end chamber. The soldier blocks have an inner side facing the end chamber and an outer side facing away from the end chamber. The soldier blocks have a rectangular cross-section at least in a bottom region thereof and the soldier blocks reach upwardly above an established level line of the glass melt. The combination includes a plurality of cooling air nozzles which are directed at the outer side of a plurality of the soldier blocks. The soldier blocks individually have on their outer side recesses diminishing a thickness cross section in thickness direction. As corrosion of the soldier blocks progresses, refractory supplementary elements are insertable into the recesses. Each recess is disposed at an upper end of each soldier block.

Abstract: A method and apparatus for preheating material in a glass melting furnace is provided. An indirect heat exchanger is utilized in which exhaust gases from the glass melting furnace are directed, in a counter flow relation, to raw materials and glass cullet being fed into a glass melting furnace. A first conduit is connected to the heat exchanger to withdraw gases formed from the decomposition of organic matter present in the materials being preheated and the gases are directed by the conduit into the glass melting furnace where they are combusted. A second conduit may also be provided for extracting water vapor released from the preheated materials prior to decomposition of the organic material.

Abstract: Regenerative glass melting furnace of the type having a batch section where glass is melted, a port neck where combustion air is introduced, and burners supplied by fuel inlet nozzles in the floor, the roof, and the lateral walls of the port neck.

Abstract: Waste is incinerated in a rotary furnace which discharges slag and exhaust gas connected to an afterburning chamber. The slag is discharged from the afterburning chamber directly into a glass melting furnace while the exhaust gas is removed to scrubbers which remove residues which are then fed to the glass melting furnace. Cullet and other glass forming materials are also added to the furnace in order to form a vitrified product.

Abstract: A filtering device for dust and exhaust gases of glass melting furnaces containing sulfurous compounds wherein the filtering medium is mineral wool which can be passed across the exhaust gas flow by means of a temperature-stable belt that matches the opening for the gas passage.

Abstract: Process for vitrifying environmentally hazardous waste material in a glass melting furnace includes forming a batch including the waste material and no more than 30 weight percent additives including phonolite and SiO.sub.2 containing substances. A gall layer 2-5 cm thick including alkali salts or alkaline earth salts is produced on the molten glass, and batch is added so that a batch layer over 5 cm thick is formed on top of the gall layer. After the batch layer is formed, the molten glass is heated solely by electrodes, and the thickness of the batch layer is maintained to produce a steep enough temperature gradient therein so that the furnace atmosphere remains relatively cool, and substantially all of the condensable components which emerge from the molten glass condense in the batch layer.

Abstract: Apparatus includes a furnace for vitrifying waste material, a storage container for delivering waste material to the furnace and a pipe for passing a heat transfer medium through the storage container to preheat the waste material and remove water therefrom. The pipe may be a pipe through which exhaust gas is passed or a pipe through which a liquid medium is passed after heat transfer from the exhaust gas. The apparatus further includes means for removing dust from the exhaust gas and heating same to break down dioxines and furanes therein.

Abstract: A plurality of conduit segments contact on another which run vertically and transversely to the direction in which molten glass is channelled. Each segment includes at least one trough section and at least one cover section, an insulation of individual formed bodies, and an external casing. The segments are coupled together on support beams and may have removable insulation at joints to facilitate inspection.

Abstract: Electrode for a glass melting furnace which avoids the disadvantages of known electrodes which are either expensive and difficult to manufacture, or have operational disadvantages, especially in regard to the delivery of electric power into the molten glass and/or in regard to trouble-free useful life. The new electrode is less costly to make and has better operational properties. The electrode shaft 2 is a coaxial tube 20 with an inner tube 21 of a metal constituting a good electrical conductor, preferably copper, and with the outer tube 22 of a mechanically strong, heat-resistant metal, preferably steel. Moreover, the electrode body 3 can be made thicker in areas of intense corrosion. The new electrode is suitable for all glass melting furnaces which are partially or entirely heated with electricity.

Abstract: Furnace has a melting section and a withdrawal section bounded by side walls of refractory material which extend to a glass outlet formed by an overflow edge remote from the melting section. In operation a molten glass layer, a molten layer of undissolved sulfates, and a batch layer succeed one another from the bottom up in the melting section. The withdrawal section is separated from the melting section by a first dividing wall extending downwardly and terminating above the surface of the molten glass. A second dividing wall is disposed for the formation of an underside glass passage, and at least one closable opening for withdrawing the molten sulfates is disposed at the level of the sulfate layer between the first and second dividing walls. The opening has a bottom boundary whose height is adjustable, so that it can be adjusted to lie above the surface of the glass melt.

Abstract: Waste substance such as incineration ash is mixed with cullet and alkaline earth salt to form a mixed batch which is added to a glass melt heated solely by electrodes, producing an exhaust gas which is introduced into the batch thereby cooling the gas to produce condensation products. The alkaline earth salt reacts with alkali in the gas and the condensation products to produce a gall layer of alkali salts and alkaline earth salts which serve as a melt accelerator and are readily removed when accumulated. According to a further step the gas is purified by separating dust therefrom and introducing it into the batch as a slurry.

Abstract: Furnace has a melting section into which batch is fed to a glass bath heated by electrodes, a homogenizing section, and a clarifying section therebetween in which fossil fuel burners heat the surface of the bath. The clarifying section is separated from the melting section by a first radiation shielding wall which extends to just above the bottom of the furnace and is interrupted by an opening above the glass for passage of combustion gases from the burners. A second shielding wall extends to above the surface of the bath and below the bottom margin of the opening in the first wall, so that combustion gases flow countercurrently through the incoming batch floating on the bath.