Abstract: The bucket-wheel excavator comprises a swivellable bucket-wheel boom 6 and a swivellable bridge 11. At a transfer location, the bridge 11 is rotatably supported on a truncated conical superstructure 10 and the turntable b 16 l of the bridge comprises raking protrusions 17, which clear the surface 18 of the superstructure 10 of debris when swivelling the turntable 16 (FIG. 1).

Abstract: A shield advancing machine, comprising cutting tools (15) rotatably supported on cantilever arms (13, 14) being rotatable around an axis approximately extending in advancing direction and being swivellable in transverse direction to this axis, has a carrier (4) which is guided and supported in axial direction of the shield (1). A rotation drive (22, 33) for a rest (9) of the cantilever arms (13, 14) is provided on the carrier (4), and the cantilever arms (13, 14) as well as their swivel drive (16, 17) are linked to the rest (9).

Abstract: In the operation of mills for the production of steel from molten pig iron and solid ferrous carriers, it is sought for economic reasons to increase the portion of solid ferrous carriers. To supply thermal carriers, such as fossile fuels, as is known, involves the disadvantages of extended charging times and of undesired accompanying elements introduced into the process.To avoid these disadvantages, the invention provides for a combination of at least one steel converter with a direct reduction plant, a meltdown gasifier and a cupola. Therein, sponge iron discharged from the direct reduction plant is melted to pig iron in the meltdown gasifier, on the one hand, and is used as solid charge for the converter. Scrap, together with coke, is melted in the cupola to blown metal, the latter, together with the pig iron produced in the meltdown gasifier, being supplied to the converter as liquid charge.

Abstract: A process for producing cooling gas for a producer gas produced in a melt-down gasifier and surplus gas usable in an appropriate manner by cooling and cleaning at least part of the producer gas and the top gas of an iron ore reduction unit are proposed. The cooling gas is exclusively obtained by preparing producer gas. There is a cooling and a cleaning unit for the surplus gas and the cooling gas in each case. A constant gas flow is passed through the rear portion of the cooling and cleaning unit for the cooling gas with the aid of a constant volume blower. That part of the producer gas supplied to the cooling and cleaning unit for the cooling gas which exceeds this constant gas flow is passed into the cooling and cleaning unit for the surplus gas.

Abstract: A metallurgical plant comprises a tiltable metallurgical vessel (1) and an enclosure surrounding said vessel. The vessel is provided with a cover (6), which is adapted to be lifted and to be horizontally pivotally moved away from the vessel (1) so as to permit the vessel to be charged by means of a charging box (5), which is suspended from a charging crane disposed outside the enclosure. To simplify the access to the metallurgical vessel (1) and substantially to prevent or minimize an escape of flue gas from the enclosure, a charging opening (8) which is adapted to be closed, is formed in the enclosure in a side wall (2) thereof which extends transversely to the horizontal axis about which the vessel (1) is tiltable, and the enclosure is formed in its top wall (4) with a top wall opening (11), which opens into the charging opening (8) and extends from the latter in the direction of said horizontal axis and is adapted to receive the crane ropes (10).

Abstract: For the purpose of introducing or removing gases into liquids or out of liquids, in particular substrates being subject to a biological conversion, rotating plates (3) are immersed into the liquid phase. The plates (3) are rotatably arranged within a tubular receptacle (1) and arranged in at least one axial section such that they alternately include with the axis (2) of rotation extending in parallel relation to the liquid level an angle of more and less than 90.degree.. Shut-off valves (9) for the gas supply conduit and for the gas discharge conduit are connected to the tubular container (1). The plates (3) are provided with a rough surface and are preferably formed of a porous, in particular foamed, material, wire mesh, wire grating or expanded metal sheet. (FIG.

Abstract: In a drift advancing machine cutting rolls are rotatably supported on a centrally arranged pivoted arm. Each cutting roll has a separate drive, each of which comprises a drive motor, a drive shaft and a driven shaft being driven via a bevel gear gearing. The drive shaft is a hollow shaft, within which is accommodated the second drive shaft.

Abstract: Apparatus for folding a sheet metal element comprises a frame, two carriers carried by the frame, and two gripping platens which are secured to respective ones of the carriers and at least one of which is movable in unison with the associated carrier transversely to the sheet metal element gripped between said platens. At least one bending tool is provided, which is movable generally parallel to the sheet metal element and is also movable transversely to the sheet metal element and is operatively connected to drive means for moving the tool in said two directions. The tool cooperates with one of the gripping platens, which constitutes a backing tool. In order to prevent a deflection of the gripping platens during the folding operation, those drive means which serve to move the bending tool generally parallel to the sheet metal element is supported by the carrier which carries that gripping platen which serves as a backing tool.

Abstract: A movable cutting machine is subdivided into a front portion (1) and a rear portion (2) of the cutting machine, which portions are swingable around an approximately vertical pivotal axis (10) and are secured against a relative displacement in direction of this pivotal axis (10) by means of two joints (11, 12). The front portion (1) of the cutting machine has a caterpillar chassis (3) and carries a swivelling means (5) comprising as the cutting means a cutting arm (6) and two cutting heads (7). The rear portion (2) of the cutting machine has, as a support means against ground, equally a caterpillar chassis (4) and carries auxiliary equipment and/or a section of a conveying trough (13) equipped with a chain conveyer.

Abstract: A method of recovering copper from oxidic and/or silicate copper ores by way of pyrometallurgy. With this method, the copper ores are melted in a reaction zone heated by plasma jets and maintained at a temperature of at least 1,500.degree. C. At this high temperature, the thermal decomposition of the oxidic or silicate copper compounds occurs, whereas no such decomposition of accompanying metal oxides takes place. The furnace used to perform this method includes a refractory lining of carbonless material. The reaction furnace and, thus, the reaction zone are sealed relative to the atmosphere to prevent oxygen from entering thereinto. An inert gas is used as plasma gas.

Abstract: In a method of producing a mixed gas from a process gas of a continuously working gasifier and a discontinuously incurred off-gas of an oxygen blowing converter, the off-gas of the refining process having the lower pressure is sucked into the process gas of the gasifier with the higher pressure via a gas jet ejector. The process gas serves as power gas, and subsequently the mixed gas is dedusted. A plant for producing steel includes a plant for recovering pig iron formed by a reduction shaft furnace and a melt-down gasifier, and at least one oxygen blowing converter for converting the pig iron into steel. The reduction shaft furnace has a process or top gas duct system, the converter has a converter off-gas duct, and an ejector connects both, the converter off-gas thus being feedable into the top gas duct system to form the mixed gas. Common dedusting and washing devices are provided for the mixed gas and safety devices for preventing oxygen from entering into the mixed gas.

Abstract: In order to ensure that a sample can be taken continuously from a reaction chamber with a minimum of maintenance work, the sample gas is extracted from the reaction chamber in two identical extraction lines in alternation and at a rate which exceeds the rate required for the analysis and surplus gas which has been extracted by one extraction line is branched from the sample gas and is blown back to the reaction chamber through the other extraction line.

Abstract: A movable device (1) for openpit mining has a plurality of excavating hammers (11) on a cantilever boom (2) being swivellable in height direction. For facilitating the continuous excavating work and for providing an adaptability to the varying angles of inclination encountered in openpit mining, at least part (23) of the carrier (6) or the carrier (6) itself is shiftable in transverse relation to the longitudinal axis (7) of the cantilever arm (2), so that on downward swivelling movement of the cantilever arm (2) in direction of the arrow (17) the whole carrier (6) or at least part (23) thereof can be shifted in transverse relation to the longidudinal axis (7) of the cantilever arm by a hydraulic cylinder-piston-aggregate (8), thereby maintaining a predetermined angle of inclination or angle of repose.

Abstract: When gasifying fuels with oxygen in a shaft-like furnace adapted to receive solid charging stock and including a primary gas chamber on its lower end to be charged by at least one burner, a fixed bed is formed in the primary gas chamber by the charging stock. The charging stock is gasified by the hot offgases from the burner. The gas forming, upon passage through the fixed bed, is extracted from the furnace as a product gas. In order to keep the product gas free of impurities that constitue a load on the environment and limit its usability, such as tar and other higher hydrocarbons, an oxygen-containing gas is injected into the furnace space filled by the product gas and a slight portion of the product gas is burnt.

Abstract: An arrangement for preheating scrap includes a scrap treating furnace into which at least one exhaust gas duct from a metallurgical furnace enters. In order to attain a higher efficiency in preheating, the scrap treating furnace has a through chamber for a plurality of adjacently arranged or superposed scrap receiving vessels. Each of these vessels is provided with its own gas inlet opening and with its own gas exit opening. The scrap treating furnace also includes a charging means on one end of the through chamber to receive at least one scrap receiving vessel and a discharging means on the other end of the through chamber to receive at least one scrap receiving vessel. A conveying means for moving the scrap receiving vessels in cycles from the charging means to the discharging means as well as gas conducting means for connecting the gas exit openings with the gas inlet openings of neighboring scrap receiving vessels are arranged within the through chamber.

Abstract: An apparatus for flanging sheet metal blanks comprises a holding-down ram (4), which is provided with a holding-down shoe (5), that is composed of a plurality of segments, which are arranged in a row and comprise a mid-segment (7) and at each end of the mid-segment a plurality of side segments (6), which are displaceable along said row, which is parallel to a bend line, about which the blank is to be flanged. To facilitate the removal of the mid-segment from the row of segments, the holding-down ram (4) carries a slider, which is displaceable in the direction of movement of the holding-down ram and has a slide track (10), which is open at least at one end and serves to guide the mid-segment (7). The slider (11) is adapted to be raised to a retracted position adjacent to a segment changer (13) for replacing a given mid-segment (7) by another.

Abstract: An auxiliary plasma arc fed by an auxiliary circuit serves for igniting a plasma arc, fed by a main circuit, of a plasma burner provided in a metallurgical furnace vessel.To increase the service lives of the burners, the electrode of the plasma burner and the melting stock charged in the furnace vessel are applied to the auxiliary circuit, with the main circuit switched off, and an auxiliary plasma arc is ignited between the plasma burner and the melting stock, whereupon the plasma burner is moved back from the melting stock, thereby lengthening the auxiliary plasma arc, and subsequently the main circuit is applied to the plasma burner and to the melting stock, and the plasma arc is ignited.

Abstract: In apparatus for flanging sheet metal blanks, a holding-down mechanism comprises a holding-down ram (3) and a holding-down shoe (4), which comprises a plurality of displaceable segments (6), which are mounted on said ram for a displacement along a track, which is carried by the ram (3) and parallel to the line of bend. The displaceable segments are displaceable along said track by adjusting rod means (17). To permit the displaceable segments to be displaced in a simple manner, each displaceable segment (6) has associated therewith a coupling (19) for non-displaceably connecting each displaceable segment (6) to an associated adjusting rod (17) and to the holding-down ram (3) in alternation.

Abstract: In order to melt particulate material in an electric furnace with the help of at least one electric arc burning between a burner electrode arranged in the lid of the furnace and a bottom electrode arranged in the bottom of the furnace, the material is introduced into a space surrounding the electric arc. It is melted by the radiation heat of the electric arc and is collected in a melt bath covering the bottom part of the furnace. In order to attain a high energy exploitation and to prevent the material to be melted from being extracted, a fixed bed of the material to be melted is formed in the space surrounding the electric arc, which takes its root on the bottom part of the furnace and peripherally surrounds the electric arc. The material is melted on the side of the fixed bed facing the electric arc. The fixed bed is moved approximately radially towards the center of the furnace to an extent corresponding to the melted material volume.

Abstract: In a mining machine (1) designed for underground operation, for example for cutting coal seams, and being equipped with a removal conveyor means taking up the heap of debris in front of the mine face and transferring this heap of debris to a removal conveyor plant (18) arranged behind the mining machine (1), there is interpositioned, separately from the mining machine, between the mining machine (1) and the removal conveyor plant (18) a crushing aggregate (2) comprising its own travel drive and being movable on a chassis in particular being equipped it caterpillars (27). The crushing aggregate (2) comprises a receiving chute (11) provided on a frame (25), a conveyor (12) starting from this receiving chute and extending with its discharge end beyond said frame and at least one crusher roll (13) within the area between the receiving chute (11) and the discharge end (15) of the conveyor (12).