Abstract: A glass furnace includes a furnace chamber for containing glass melt and a screw conveyor for receiving glass batch material and feeding the glass batch material to the furnace chamber. A dam wall is disposed with respect to the screw conveyor such that batch material from the screw conveyor must flow upward over the dam wall before entering the furnace chamber. The top of the dam wall may be below the level of the melt pool in the furnace chamber.

Abstract: In plasma deposition processes for producing an optical preform according to the POD method, a cladding glass layer composed of fluorine-doped quartz glass is produced by means of a plasma torch on a cylindrical substrate body composed of quartz glass, said substrate body rotating about the longitudinal axis thereof. In this case, the plasma torch performs a reversing relative movement between two turning points (A; B) along the substrate body. In order, proceeding therefrom, to achieve a high fluorine doping in conjunction with a dopant distribution that is as uniform as possible axially, the invention proposes that a heat element has a heating effect on the region of one turning point (A; B) when the plasma torch is situated in the region of the other turning point (B; A).

Abstract: A method and an apparatus for feeding preheaters having heating elements for the feedstock of glass melting installations. In order to distribute the feedstock in an extremely thin, but uniform layer thickness on and between the upper heating elements, thereby effectively suppressing or avoiding agglutination of particles and accumulation of the feedstock, a distributor device is arranged above the topmost heating elements including at least three pivotable distributor plates, the pivoting axes of which run in the horizontal edges of a virtual prism. The topmost distributor plate throws the feedstock alternately onto one of the distributor plates arranged underneath, which throws the caught feedstock to one of its sides sternwards. The movements of the distributor plates are controlled by sensors with an evaluation and control circuit and actuators assigned to the distributor plates with the aim of a uniform area distribution of the feedstock over the cross section of the preheater.

Abstract: A method of increasing efficiency in glass batch melting by controlling the reaction paths of batch constituents as they melt, preventing early formation, flow, segregation and pooling of low-viscosity liquids. The glass batch raw material components are separated into first and second portions with different respective compositions, resulting in first and second respective compositions having first and second respective reaction paths. The respective portions are combined with remaining raw materials to define a mixture which is then introduced into the melter and reacted to yield a homogeneous glass melt. The first composition has a first melting temperature having a first reaction path resulting in a first liquid having sufficient viscosity to minimize flowing. The second composition has a second melting temperature and the first liquid fluxes the second composition to yield a molten glass composition.

Abstract: The subject invention is directed to a method for producing a pre-reacted clinker used in the manufacture of E glass. The clinker is fed into an E glass furnace, and melts down into a finished E glass product at high efficiencies and short production times. The clinker allows glass to be produced at a lower cost as compared with known methods.

Abstract: A method and a system for thermal dewatering and preheating aqueous mixtures for feeding glass melting plants when passing through a shaft-like container provided with heating elements disposed one above another in tiers. To avoid the feed material from becoming glued together or agglomerating in the preheaters while the feed material is heated by exhaust gases with separately guided exhaust gases and feed material, a) the uppermost tier heating elements are closed relative to the mixture and are kept above 100 C, b) the interface between the mixture and the atmosphere above the mixture is shaped and heated by the uppermost tier heating elements so that part of the thermal output is emitted to the atmosphere via the mixture, and c) as the mixture proceeds through the container it is heated by further heating elements to temperatures close to the glass melting plant feeding temperature.

Abstract: The invention relates to a furnace for the continuous melting of a composition comprising silica, the said furnace comprising at least two tanks in series, said tanks each comprising at least one burner submerged in the melt. The invention also relates to the process for manufacturing compositions comprising silica using the furnace, the silica and the fluxing agent for the silica being introduced into the first tank. The invention makes it possible to produce glass color frits, tile frits and enamel with a high productivity, low temperatures and short transition times.

Abstract: The invention relates to a method for producing mineral wool, wherein a mineral base material is melted in a cupola furnace having a shaft to hold the base material, the lower section of said shaft being provided with a grate, and beneath said grate there is a combustion chamber. The combustion chamber is heated by one or a plurality of burners, the burner or burners being run on liquid or gaseous fuel and an oxygen-containing gas. The burners are operated such that the length of the flames occurring during combustion of the fuel with the oxygen-containing gas is between 60% and 100% of the combustion chamber diameter.

Abstract: An apparatus for preheating a batch (12) of glass cullet which is preferably enriched with raw materials for glass production, comprising a bunker (14) preferably having flow ducts for the passage of warm (off)gas. To discharge the preheated batch of glass cullet from the bunker, the apparatus has one or more discharge worms (26), by way of which the batch of glass cullet can be conveyed to at least one outflow opening (28) in the base region of the bunker (14).

Abstract: Heat in a stream of combustion products obtained from a glassmelting furnace heated by oxy-fuel combustion is passed to incoming glassmaking materials in a heat exchanger without requiring reduction of the temperature of the stream yet without causing softening of the glassmaking material.

Abstract: Heat in a stream of combustion products obtained from a glassmelting furnace heated by oxy-fuel combustion is passed to incoming glassmaking materials in a heat exchanger without requiring reduction of the temperature of the stream yet without causing softening of the glassmaking material.

Abstract: The subject invention is directed to a method for producing a raw material or materials that can be used by themselves or in combination with other ingredients to make glass of high quality at high efficiencies and short production times. The raw materials are capable of high reactivity in a glass melting furnace and therefore will allow glass to be produced either at lower temperatures or shorter residence times at the same temperatures as compared with known methods.

Abstract: A method of forming a glass melt, including measuring predetermined amounts of raw materials to define a glass batch, combining predetermined amounts of sources of silica, calcia and boron from the glass batch to yield a first pre-batch, substantially consolidating the first pre-batch into first pre-batch granules, combining predetermined amounts of sources of silica, calcia, and alumina from the glass batch to yield a second pre-batch, mixing the first and second pre-batches and any remaining portion of the glass batch to yield a batch mixture, and heating the batch mixture to yield a glass melt. Typically, the raw materials at least include sources of silica, alumina, calcia and boron and each respective first pre-batch granule defines a cohesive agglomerate.

Abstract: The subject matter disclosed herein generally relates to glass compositions for protecting glass and methods of making and using the compositions.

Abstract: In order to provide a quartz glass crucible distinguished by high purity, high opacity and/or low transmissibility in the IR spectrum, it is proposed on the basis of a known quartz glass crucible of opaque quartz glass with a crucible body symmetrical in relation to a rotational axis, an outer zone (3) of opaque quartz glass transitioning radially toward the inside into an inner zone (2) of transparent quartz glass and with a density of at least 2.15 g/cm3, that according to the invention, the crucible body (1) be made of a synthetic SiO2 granulate with a specific BET surface ranging from 0.5 m2/g to 40 m2/g, a tamped volume of at least 0.8 g/cm3 and produced from at least partially porous agglomerates of SiO2 primary particles.

Abstract: A method and apparatus is taught for preheating of glass batch materials by direct contact with glass furnace exhaust gases. Furnace gases 15 flow through a batch hopper 1 in horizontal tunnels formed by open bottom tubes 6, with a free surface of batch forming the bottom portion of the tunnel. The tubes are electrically grounded and a high voltage discharge electrode 18 is located axially in each tunnel. The corona discharge from the electrode acts to retain batch and prevent it's entrainment into the flowing gases. Particulate matter from the gases is simultaneously precipitated onto the batch surface. Acidic gas components such as SO2, HCl, and HF are chemically reacted with batch constituents, thereby removing them from the gas stream. Heat is transferred from the gases to the batch by direct contact. Cooled gases 16 exit the hopper, cleaned of pollutants to levels in compliance with strict environmental regulations.

Abstract: Present invention suppresses undesirable effects of the bubbles trapped in a silica glass crucible on single crystallization during the pulling process under a high-temperature load. When raw material powder is melted in a mold 1, graphite components of electrodes and impurities contained in the raw material are removed by introducing hydrogen gas and/or oxygen gas immediately after the start of arc discharge. Graphite and impurities are prevented from entering the product crucible, thereby suppressing the volume increase rate of the bubbles and reducing the inner pressure of the bubbles. Gases remaining in voids of an accumulated layer of silica powder formed inside the mold 1 can be replaced with helium gas, by supplying helium gas to the accumulated layer from the mold 1.

Abstract: This apparatus is a furnace for heating molten material which employs oxygen-fuel burner assemblies. Preferably, the assemblies are submerged in the molten material. They are water cooled top down units with burner nozzles being off-set from the supply column. The apparatus utilizes one or more burners for each top down supply column. The supply column and attached burners can be rotated or moved in a manner to avoid the open chimney effect seen with fixed air-fuel burners of the prior art. These burners with an off-set nozzle like the letter L are rotated at high speed or oscillated to distribute the combustion in the form of gas bubbles or a gas curtain. In another embodiment, the oxy-fuel burners are not submerged. The nozzles are aimed at unmelted batch or the upper surface of the molten material for controlled splashing.

Abstract: A wet batch material charging apparatus having a charger screw housing having a batch material inlet and a batch material outlet, a dry batch material supply device adapted to deliver a dry batch material through the batch material inlet, a rotatable charger screw shaft having at least one screw flight disposed within the charger screw housing and adapted to convey the batch material from the batch material inlet to the batch material outlet, and a liquid supply apparatus for introducing at least one liquid into the charger screw housing. The liquid supply apparatus independently controls the liquid flow rate and the liquid flow duration based upon the batch material charging speed and rotation of the rotatable charger screw shaft.

Abstract: Provided herewith is a method for preheating a glass mixture to be fed into a glass furnace. The method comprises separately preheating at least some of the materials which comprise the load, and then subsequently remixing the preheated materials and passing the load to the glass furnace.

Abstract: During the melting of glass from charging material in furnaces with burners and regenerators for the recovery of waste heat, oxygen and primary fuel are introduced into the area around the flame roots under slightly sub-stoichiometric conditions to cover the heat requirement of the melting process. In order to further reduce the levels of NOx, and CO in the waste gases by re-burning or post oxidation, secondary fuel and, further downstream, additional air are introduced beyond the flame in order to reduce the level of NOx, in or above the checkerwork by means of the secondary fuel and to carry out re-burning or post oxidation downstream by means of the supply of air, so that ultimately approximately stoichiometric combustion takes place. Before the waste gases enter a waste gas stack they are used to preheat the charging material in at least one raw material pre-heater.

Abstract: A method for making glass and particularly ceramic frits, comprising the steps of: introducing in a wet grinding unit, after a metering step according to chosen proportions, materials which constitute a mixture to be melted, to produce a slurry; screening and collecting said slurry in a storage tank; introducing the collected slurry in a melting furnace to make a liquid component of the slurry evaporate; and forming a melted paste of vitreous material, adapted to be converted into a ceramic frit.

Abstract: A method and apparatus is taught for preheating of glass batch materials by direct contact with glass furnace exhaust gases. Furnace gases 15 flow through a batch hopper 1 in horizontal tunnels formed by open bottom tubes 6, with a free surface of batch forming the bottom portion of the tunnel. The tubes are electrically grounded and a high voltage discharge electrode 18 is located axially in each tunnel. The corona discharge from the electrode acts to retain batch and prevent it's entrainment into the flowing gases. Particulate matter from the gases is simultaneously precipitated onto the batch surface. Acidic gas components such as SO2, HCl, and HF are chemically reacted with batch constituents, thereby removing them from the gas stream. Heat is transferred from the gases to the batch by direct contact. Cooled gases 16 exit the hopper, cleaned of pollutants to levels in compliance with strict environmental regulations.