Abstract: A gas washing device includes a permeable gas sink, a gas inlet for supplying gas through the sink to a molten metal container, a gas flow meter positioned upstream of the gas inlet, and a further gas sink having a gas permeability greater than that of the first-mentioned gas sink and positioned between the gas inlet and the first-mentioned gas sink.

Abstract: A casing assembly includes a nozzle brick to form part of a wall of a metallurgical vessel. The nozzle brick has therethrough a conical opening defined by a conical inner surface. A casing to be inserted into the conical opening has a truncated conical shape including a conical outer surface and an axially extending flow through opening. The conical opening and the casing have coaxial center axes, and the conical inner and outer surfaces extend at equal angles of inclination to such axes. The conical inner surface is jacketed with a thin metal shell having a conical shape with the same inclination as that of the conical inner and outer surfaces.

Abstract: The invention relates to a ceramic molding which is manufactured from high-temperature resistant, fire-resistant or refractory fibers and fine-grain, fire-resistant or refractory materials and, in certain cases, from other customary additives. The ceramic molding is characterized by the fact that its porosity gradually and continuously increases along an axis of the molding from less than 20% to more than 70%. The areas with low porosity comprise the fine-grain, fire-resistant or refractory materials. The areas of high porosity comprise ceramic fiber, such as, fibers of Al.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2, C, SiC or mixtures thereof. The intermediate areas are constructed of mixtures of ceramic fiber and fire-resistant or refractory materials. The invention also relates to the use of such a ceramic molding method for the manufacture of compound moldings saturated or infiltrated with organic resins, pitch, tar, metals, metal alloys or glasses.

Abstract: A refractory plate used as a stationary and/or as a movable closure plate in a sliding closure unit for discharging molten metal from a metallurgical vessel includes a refractory plate body having parallel opposite planar surfaces. A first discharge opening extends through the body between the parallel surfaces and is used for initial operation. At least one other discharge opening extends through the body between the parallel surfaces and is sealingly closed by a stopper plug of refractory material. Upon erosion damage to the first discharge opening, such damaged opening may be closed by a stopper plug of refractory material, the stopper plug may be removed from the other discharge opening, and the plate may be reversed such that the other discharge opening then is employed for further operation of the plate.

Abstract: A gas scavenging apparatus for a metallurgical vessel containing molten metal includes a frusto-conical refractory inner scavenging block inserted in the refractory lining of the vessel and having a smaller end surface facing the molten metal and a larger base end directed away from the molten metal. A frusto-conical refractory outer scavenging block is embedded within a mounting brick positioned outwardly of the inner scavenging block. The outer scavenging block has a smaller end surface smaller than and facing the larger base end of the inner scavenging block and a larger base end directed away from the inner scavenging block. The larger base end of the inner scavenging block has an annular end surface extending generally radially outwardly away from the smaller end surface of the outer scavenging block and resting on the mounting brick. Scavenging gas is passed through the outer scavenging block and then through the inner scavenging block to the molten metal.

Abstract: A catalyst for use with ammonia for the selective reduction of nitrogen oxides in waste gases. The catalyst comprises a mixture of substances which has high activity and selectivity with regard to nitrogen oxide conversion and high sorption capabilities with regard to ammonia, but low oxidation capabilities with regard to sulfur dioxide, ammonia, or similar substances. The invention also provides a process for the manufacture and use of such catalysts.

Abstract: A gas rinsing stopper includes a stopper member having therethrough an axial gas passage, a mounting fixture extending into a first end of the gas passage, a gas feed opening at a second end of the passage, and a gas supply line extending into the gas passage. A seal member is positioned within the gas passage and forms a gas tight seal separating the gas passage into a first section including the mounting fixture and a second section leading to the gas feed opening. The gas supply line opens into the second section of the gas passage, such that rinsing gas supplied through the gas supply line is isolated from the first section of the gas passage. This prevents the supply of rinsing gas from creating a reduced pressure at the first end of the gas passage, and thereby prevents atmospheric air from being drawn into the gas passage and mixing with the rinsing gas.

Abstract: This invention relates to mounting porous ceramic material to metal surfaces. The metal surfaces may either be flat surfaces or tubes. The ceramic material is held onto a perforated metal sheet by screwed-in spiral springs. The perforated metal sheet acts as a holding device and is located adjacent to a metal surface. The invention provides for porous ceramic insulation which is conveniently mounted with relation to the metal surface. Spiral springs absorb the stresses which occur during use.

Abstract: A catalyst for use in a process for the removal of nitrogen oxides from exhaust gases contaminated with dust in which the process uses ammonia. The catalyst is made of a material which is easily disposable. Furthermore, the catalyst should be completely used up in the catalysis. The catalyst comprises individual ceramic bricks with a porous surface, and passages therethrough for the flow of the exhaust gases. The bricks exhibit a resistance to abrasion which is designed so that the dust of the exhaust gas which flows through the passages erodes the catalyst surface, thereby reactivating the catalyst. The exhaust gas carries the dust and the eroded material along with it.

Abstract: The invention relates to an air-cooled combustion chamber wall for combustion furnaces. The combustion chamber wall comprises at least one masonry wall with a space in the middle for the passage of cooling air along the side of the wall away from the combustion chamber side. To create a simple, stable and effective structure, the invention proposes that the masonry be made of bricks, whose walls enclose at least one air duct.

Abstract: In a process for the reactivation of a catalyst, which is used for the removal of NO.sub.x, oxides of nitrogen, from exhaust gases, the catalyst should be capable of easy reactivation. For this purpose, when the catalyst starts to lose its activity, it is exposed in a reducing atmosphere to a carbon monoxide current. In an apparatus for the execution of the process, the catalyst is placed in two separate chambers. The carbon monoxide stream is directed alternately to both chambers.

Abstract: An electrode for an electric arc furnace includes a cooled metal sheath covered with a refractory protective jacket. A plurality of refractory anchors are fixed to the exterior of the sheath, and the anchors are spaced from each other. The protective jacket includes an undercoat on the exterior of the sheath and a protective layer over the undercoat and extending between the anchors. The protective layer is formed of a refractory material such that, at the operating temperature of the electrode, the protective layer has an inner zone which is thermoplastic and an outer zone which is rigid or which is a high-viscosity melting phase.

Abstract: An immersion pouring spout for introducing molten metal, such as steel, into an ingot mold is provided with a top head and a cylindrical pouring tube including a protective external jacket attached by cement to the pouring tube and extending the entire length of the pouring tube. The jacket material has a thermal conductivity that is less than the thermal conductivity of the pouring tube material.

Abstract: A refractory article for casting of liquid melts, especially steel, fabricated from a mixture of Al.sub.2 O.sub.3, graphite, a flux component, a synthetic resin binder and a metallic powder. The flux component contains a first flux with a melting point from 550.degree. to 900.degree. C. and a second flux that becomes active in the mixture in a temperature ranging from 1350.degree. and 1550.degree. C. The refractory article need not be heated before use, and the carbon contained therein, which determines the strength of the article, is retained for a much longer period during use, so that the article will have a long service life.

Abstract: The temperature of humid environmental air is reduced by passing the air, in a first stage, through a moisture storage agent and therein substantially freeing the air of the moisture content thereof. In a second stage, the air is passed through a heat storage agent and therein the temperature of the air is lowered without changing the humidity thereof. In a third stage the thus dried and cooled air is passed through a moisturizing system, and therein the moisture content of the air is increased and the temperature of the air is further lowered.

Abstract: A refractory conduit assembly for the transfer of molten steel from a discharge vessel to an ingot mold of a horizontal continuous casting plant includes a replaceable spout member adapted to be removably connected at a predetermined location to the refractory lining of a vessel. The spout member has therethrough a discharge channel to receive from the interior of the vessel a flow of molten steel. A shut off device is provided to interrupt the flow to the discharge channel. A casting tube has therethrough a flow passage with inlet and outlet ends. A coupling device connects the inlet end of the flow passage to the discharge channel, such that the flow of molten metal passes through the casting tube. The outlet end of the flow passage has an altered cross-sectional configuration adapted to that of the ingot mold. A nozzle has an inlet end connected to the casting tube and an outlet end having thereat a portion to sealingly contact walls of the ingot mold.

Abstract: A recuperator includes plural ceramic recuperator tubes arranged vertically on top of each other. Each tube has an outer periphery, first and second opposite ends, and a gas passage extending longitudinally between such ends. The first end includes an annular sealing surface extending radially inwardly from the periphery and an annular projection defined by a conical surface extending axially from the sealing surface to an end surface of the first end. The second end includes a square flange extending outwardly from the periphery and a stepped seal extending axially inwardly into the flange from an end surface of the second end.

Abstract: An apparatus for replaceably connecting a casting tube to a closable pouring spout of a tundish includes a gimbal device for supporting the casting tube and a double-arm lever including a first arm supporting the gimbal device and a second arm carrying a counterweight. The lever is supported about an axis such that the counterweight pivots the lever about the axis and causes the first arm and the gimbal device to press the casting tube against the mouth of the pouring spout. Supports are fixed to the tundish, a pin member defines the axis, and a mounting structure moves the pin member between an operative position pivotally supporting the lever on the supports and an inoperative position where the lever is released from the supports.

Abstract: Process for the long-duration removal of polychlorinated biphenyls (PCB) from transformer-insulating liquids when substituting insulating liquids, particularly silicon oils, for PCB oils. The PCB contaminants can be removed continuously or substantially continuously from the transformer-insulating liquids using an adsorption resin, thus preventing PCB from accumulating in the transformer-insulating liquid. The insulating liquid is passed substantially continuously through the adsorption resin; adsorption resin, after enrichment with PCB oil, is washed with a solvent for PCB oils; and the washed resin is freed from residual solvent by rinsing it with a gas prior to reusing the thus regenerated resin to adsorb additional PCB oil.

Abstract: Method of producing a refractory light-weight brick from a mixture of a granular refractory material, a binder, a foaming agent, further addition agents, and water, wherein the mixture is poured as a foamed, aqueous slurry into molds and the set moldings are dried and fired. The mixture contains, by weight, 1-10% hydrated aluminumhydroxychloride, 0.1-3% magnesia (MgO) and 87-97% refractory material. The slurry sets rapidly in the molds.