Abstract: The invention concerns a method for cooling a shaft furnace loading device, said loading device being equipped with a ring-shaped rotary joint (40), provided with a fixed ring-shaped part (56) and a rotating ring-shaped part (46), for supplying cooling liquid to a rotating cooling circuit (36, 38). The invention is characterized in that it consists in feeding the joint (40) fixed part (56) with cooling liquid such that a leakage flow passes in a separating ring-shaped slot (58, 60) between the fixed part (56) and the rotating part (46) of the joint (40), to form therein a liquid joint. Said leakage flow is then collected and drained without passing through the cooling circuit (36, 38).

Abstract: In order to configure a bell and hopper for shaft furnaces, in particular, blast furnaces, comprising a charging bin with a feed tube, a rotating chute carrier with rotary drive, a swiveling chute in the interior of the furnace with drive means arranged external to a housing, in a less failure-prone and a wear resistant way, the drive means for the swivel movement of the chute are to comprise: at least one motor (7) which drives by a respective pinion (8) a crown gear (9), wherein the crown gear (9) engages the spindle gear wheels (11) of at least two spindles (13) distributed about the periphery of the bell and hopper external to the rotating chute carrier (3) for generating a lifting and lowering movement of the spindles, as well as means (14, 15, 17, 21) for transmitting this vertical movement of the spindles onto the tilting shafts (22), which penetrate the inner wall (24) of the chute carrier (3) and from which the chute can be suspended, for generating a swivel and tilting movement of the chute.

Abstract: A method and apparatus for increasing hydrocarbons to a direct reduction shaft furnace while controlling the temperature uniformity of the center portion of the iron burden wherein the hydrocarbon gases used in direct reduction may be preheated, which increases the temperature of the hydrocarbon gases, and therefore increases the resultant temperature of the upflowing gases as it rises from the lower section of the furnace into the center of the burden. Alternatively, a portion of the upflowing gas may be removed before it enters the reduction zone of the furnace. The removed upflowing gas, known as hot bleed gas, may be ducted to the top gas scrubber of the furnace or may be mixed with the main reducing gas stream of the furnace for reintroduction to the furnace. Alternatively, hot reducing gas may be directly injected into the center portion of the burden, offsetting the cooling effect of the upflowing gas.

Abstract: The invention relates to a shaft furnace, in particular a direct-reduction shaft furnace, with a charge composed of particulate material, in particular a particulate material containing iron oxide and/or sponge iron, the said material being capable of being fed into the shaft furnace from above, and with, arranged in one plane, a multiplicity of gas-inlet orifices for a reduction gas in the region of the lower third of the shaft furnace, the shaft contour having a diametral widening and a cavity being formed between the gas-inlet orifices and the charge. The shaft furnace according to the invention makes it possible to supply gas to the shaft furnace so as to be distributed uniformly over its circumference.

Abstract: The present invention refers to an equipment for feeding and distributing charge and fuel in furnaces of rectangular cross section, comprising movable feeding tubes to distribute along the longitudinal section and the cross section of the furnace, both a charge comprised of self-reducing agglomerates, ore, scrap or any other metallic material, and solid fuels of any kind.

Abstract: A direct reduction device (10) of the gravitational type to obtain iron carbide starting from iron oxide, comprising a reduction and carburation reactor (12) below which a cooling and passivation container (26) is arranged wherein the iron carbide is suitable to be cooled and passivated, between the reactor (12) and the container (26) a valve for solids (24) is interposed suitable to regulate the transfer of the iron carbide.

Abstract: Device for the direct reduction of iron oxides of the type with a gravitational load, comprising a reactor defining, in its upper part, at least a zone inside which the reduction reaction occurs, means (14, 15) to introduce the load through a mouth (12) of the reactor, means (18, 17, 19) to introduce a current of gas into at least one section of the reactor in correspondence with the reduction zone, outlet means (13) of the reduced material from the bottom of the reactor, and means (20) to discharge the exhaust fumes, said reactor (10) including at least a first upper zone (10a) of heating, pre-reduction and final reduction, with a taper diverging downwards, and a second lower zone (10b) of carburization and cooling, with a taper converging downwards.

Abstract: The present invention relates to a method and apparatus for separating undesired toxic metals, such as Zn, Pb and Cd, from iron-containing materials by: sintering a mixture of such materials (typically including EAF dust and mill scale) with carbonaceous particles to form sturdy sinter lumps; preheating such lumps in a non-reducing atmosphere, if needed, to achieve an elevated temperature generally above the vaporization temperature of the undesired metals, but below the sticking temperature of iron-containing lumps (which is typically below the vaporization temperatures of such undesired metals in their oxide form), feeding the lumps at such elevated temperature into a reduction reactor; flowing hot reducing gas through lumps to volatilize undesired reduced metals and carry the volatilized metals out of reduction reactor leaving the iron-containing lumps largely stripped of the undesired metals and ready for discharge and safe and/or useful disposal or re-use, and finally cooling the off gas from the reactor

Abstract: A solidified residual iron within a blast furnace is suspended up by employing a shell suspending device fixed to a tuyere arranged in a lower end portion of an upper portion of a furnace body suspended by a lift jack and a solidified residual iron suspending band, thereafter is descended by employing the lift jack and is mounted on a horizontally moving table. Subsequently, the horizontally moving table mounting the solidified residual iron thereon is moved onto a furnace outer truck rail from a furnace inner truck rail so as to be taken out of the furnace by operating a center hole jack arranged near the furnace outer truck rail, whereby an operation of taking out the solidified residual iron within the blast furnace out of the furnace is economically performed for a short time.

Abstract: Gravitational type furnace for the direct reduction of mineral iron comprising a median reaction zone (14) in which the reactions to reduce the mineral iron occur, means (12, 13) to feed the mineral iron to said reaction zone (14), distribution means (16, 17, 18) to introduce reducing gas into said reaction zone (14), discharge means (15) to discharge the reduced metal iron, and an intake device (20) for the reducing gas, said intake device (20) being positioned in correspondence with a chamber (21) situated above said reaction zone (14), a toroidal grid (22) being arranged in said chamber (21).

Abstract: The invention relates to a shaft furnace (1), in particular a direct-reduction shaft furnace, having a bed (2) of lumpy material, in particular lumpy material containing iron oxide and/or iron sponge, having worm conveyors (3) which penetrate through the shell of the shaft furnace for discharging the lumpy material from the shaft furnace (1), which conveyors are arranged above the base area of the shaft furnace (1) and are mounted in the shell of the shaft furnace.

Abstract: According to a process for injecting metal-oxide-containing fine particles into a reducing gas, a central material stream formed by the fine particles and a carrier gas is introduced into the reducing gas and at least one gas stream formed by a secondary gas is directed against the material stream to ensure an optimum contact of the fine particles with the reducing gas, the gas stream atomizing the material stream and the fine particles being evenly distributed within the reducing gas.

Abstract: An improved method and apparatus for increasing the productivity of a direct reduction process in which iron oxide is reduced to metallized iron by contact with hot reducing gas; comprising the steps of: a) providing a first hot reducing gas consisting essentially of CO and H2; b) providing additional reducing gas by reaction of a gaseous or liquid hydrocarbon fuel with oxygen; c) mixing the first hot reducing gas with the additional reducing gas to form a reducing gas mixture; d) enriching the reducing gas mixture by the addition of a gaseous or liquid hydrocarbon; e) injecting oxygen or oxygen-enriched air into the enriched mixture; and f) introducing the enriched mixture into an associated direct reduction furnace as reducing gas.

Abstract: A vertical shaft furnace for melting scrap metal, particularly copper scrap, uses one or more burners operated superstoichiometrically in order to provide excess oxygen to react with a waste gas stream passing up through the copper scrap thereby reducing the amount of carbon dioxide and visual contaminants in the waste gas stream.

Abstract: A method of blowing a synthetic resin material into a furnace comprising preparing a synthetic resin material having an average specific surface area of at least 50 m2/kg; and blowing the synthetic resin material from tuyeres of a shaft furnace for ironmaking.

Abstract: Method and apparatus for smelting iron ore in which iron ore is preheated and partly reduced within a first reaction zone and then further reduced in a second reaction zone. The first reaction zone can be a shaft reduction furnace and the second reaction zone can be a melter gasifier. An auxiliary third reaction zone partially oxidizes a carbonaceous material to produce char for the third reaction zone. A reducing gas produced by partial oxidation of the char is used to effect the partial reduction conducted within the first reaction zone. Volatile substances contained within a heating gas produced by the partial oxidation within the auxiliary third reaction zone is further oxidized and used to preheat the iron ore within the first reaction zone.

Abstract: An apparatus for the direct reduction of iron oxide utilizing a shaft furnace equipped with a bustle and tuyere system having multiple rows of tuyeres. The bustle and tuyere system utilizes multiple rows of tuyeres to aid in the reduction of gas velocities through the system and to improve burden flow.

Abstract: In order to preheat pieces of iron scrap of various sizes and shapes highly effectively while avoiding the fusion of the pieces of iron scrap, a rotary kiln type preheating furnace and a shaft type preheating furnace are arranged in parallel with each other in the front stage of a melting furnace in which iron scrap is melted, and preheated iron scrap is charged from both preheating furnaces into the melting furnace. A damper is provided between the shaft type preheating furnace and the melting furnace, so that exhaust gas discharged from the melting furnace is prevented from directly flowing into the shaft type preheating furnace and introduced into the rotary kiln type preheating furnace. Exhaust gas which has passed through the rotary kiln type preheating furnace is introduced into the shaft type preheating furnace preferably from an upper portion and discharged from a lower portion.

Abstract: A cupola emission control system is provided that includes both improved physical emission control equipment and improved controls for operating such equipment. The physical emission control improvements include an orifice ring of restricted diameter above the cupola main afterburners to improve the turbulence of the air in the upper cupola area to allow improved combustion of carbon monoxide. Further, twin venturis are provided with improved air passage control equipment to affect the temperature in the upper cupola combustion area. Further, an improved control system is provided whereby actual time calculations are made for remaining emission permitted amounts of certain pollutants, mainly carbon monoxide, and real time adjustments are made for cupola operation to assure compliance with such permitted emission limits.

Abstract: A smelting reduction apparatus and a method for producing molten pig iron using the smelting reduction apparatus are disclosed. The molten pig iron is produced by using iron ore, sintered ore or iron pellets, so that the reduced iron discharge operation from a pre-reducing furnace to a melter-gasifier would not give any influence to the operation of the pre-reducing furnace. An iron ore is pre-reduced at a pre-reducing furnace by utilizing a reducing off-gas which is produced from a melter-gasifier. The pre-reduced iron ore is melted and reduced at the melter-gasifier. The reducing gas which is discharged from the melter-gasifier is supplied through an ascending duct and a cyclone into the pre-reducing furnace. The fine iron ore which is collected at the cyclone is spouted through a recycling device and a melter-burner into the melter-gasifier.

Abstract: Described herein is an Improved Converter System designed to help reduce air, land and water pollution by completely converting materials that presently cause pollution into clean burning fuels and a host of other products beneficial to mankind. The primary conversion unit in the system is a zone controlled multipurpose slagging-ash oxygen jet blast converter. All incoming materials are passed through this process computer aided talented offspring of its two ancient prototypes the blast furnace and slagging-ash gas producers and the zone controlled blast furnaces described in U.S. Pat. Nos. 4,381,938, 4,495,054, 3,928,023 and 3,814,404. It employs two sets of tuyeres located in the bosh to input endothermic reacting gases, vapors and dusts through tuyere sets T1 and T2. A 100% oxygen jet blast is also input through tuyere set T2.

Abstract: A process and apparatus for the production of reformed gases. Natural gas and oxygen are combusted in a first stage to produce carbon dioxide and water. The products of combustion are conveyed to a second stage. Reforming gas and oxygen are injected into the second stage and mixed with the products of combustion to react with the carbon dioxide and water to produce carbon monoxide and hydrogen. The process and apparatus are particularly adapted for use in supplementing the reform gases produced in a Direct Reduced Iron plant wherein iron ore is reduced to iron inside a shaft furnace. The process and apparatus may also be used to provide heated enrichment natural gas for use as a source of carbon in the shaft furnace to provide for carburization of the iron. Additionally, the process and apparatus may be used as a process control device for controlling the temperature of the reformed gases flowing to the shaft furnace.

Abstract: An apparatus for charging a shaft furnace, in which each of plane faces of a second segment of a guiding member of a unit for distributing a burden over a cross section of the furnace is formed so that its first line of intersection with a first vertical plane passing through its geometric center and tangentially to a circle lying in a horizontal plane and having the center on an axis of the furnace and the radius equal to the distance from the furnace axis to the geometric center, is inclined at angle ".alpha." to the horizontal plane, the intersection lines of all plane faces forming a polygonal line, each subsequent length of the polygonal line, in a burden flow direction, making a greater angle of inclination with the horizontal plane than the preceding one, and a second line of intersection of each plane face with a second vertical plane passing through its geometric center and the furnace axis is inclined at angle ".beta." to the horizontal plane, with angle ".beta." increasing with the burden flow.

Abstract: An improved hearth section for a shaft furnace may comprise a plurality of splines mounted to the side wall of the hearth section in spaced-apart circumferential positions so that each of the splines extends radially inward from the side-wall and into the interior of the hearth section. The floor of the hearth section may include a plurality of stand-offs positioned in generally spaced-apart relation and that extend upward from the floor and into the interior of the hearth section.

Abstract: The present invention concerns a plate (1) for cooling a blast furnace and forged or rolled out of a blank of copper or mainly-copper alloy.Vertical bores (3) extend into the plate. A detachable furnace-cooling component (4) with vertical bores (5) and horizontal bores (6) extending into it is attached to the top or bottom of the plate.Coolant is pumped into and out of the bores in the furnace-cooling component through sections (2) of pipe and into and out of the bores in the plate through other sections (2) of pipe. Both cooling systems communicate with the furnace's cooling system by way of the pipe sections (2), which extend through the furnace plating (10).

Abstract: A device for transporting molten metal in the pouring bay of a blast furnace and a process for operating this device. At least one main runner with skimmer, which main runner is installed after the tapping door of the blast furnace, is provided as well as runoff gutters arranged downstream with a transfer station into the molten metal transfer cars. A pipe section with connecting branches, which is followed by a second pipe section with a slide, is flanged to the runout in a gas-tight manner. This second pipe section is also connected in a gas-tight manner to the intake opening of the main runner. A T-shaped pipe section, which allows the pig iron to flow into one of the pig iron transfer cars, is arranged at the end of the pipe sections. To keep clear the open cross section of the wear lining of the pipe section, inert gas is blown in, which also keeps the ceramic plate of the sliding shutter clear.

Abstract: A coke-fired cupola, including: a furnace shaft having a well at one end, a charging device connected to the shaft, a lower-mouth exhaust connected to the shaft below the charging device, and a furnace gas exhaust ring arranged at the shaft below the charging device and the lower-mouth exhaust. Additionally, at least one nozzle is connected to the shaft above the well. The at least one nozzle has a centrally run oxygen lance. A gas recirculating circuit is provided for connecting the furnace gas exhaust ring to the at least one nozzle. The gas recirculating circuit includes an exhaust device connected to the furnace gas exhaust ring, a recirculating gas ring connected to the at least one nozzle and a recirculating gas duct connected between the exhaust device and the recirculating gas ring.

Abstract: A shaft furnace, e.g. a blast furnace, has a bosh, a shaft and a mantle ring at the transition from the bosh to the shaft. At both the bosh and the shaft, there is a steel jacket and a refractory lining on the inside of the steel jacket. Cooling elements extend into the refractory lining from the steel jacket and are arranged for through-flow of cooling liquid. To provide additional cooling at the critical transition from the bosh to the shaft adjacent the mantle ring, there is at least one transition cooling element located near the mantle ring so as to cool a region of the refractory lining of the bosh adjacent the steel jacket at the transition. The transition cooling element has, as seen in plan view, a T-shape, with the cross-bar of the T-shape extending in the circumferential direction of the furnace.

Abstract: A molten salt process vessel for treatment of hazardous materials such as explosive or propellant waste, employing a tall, thin vessel with sufficient height that salt splash from the molten salt at the bottom of the vessel can be controlled and hard salt deposits are prevented from forming on the walls which restrict the gas outlet. The vessel, e.g. of cylindrical shape, has an increased height to diameter ratio in the range of about 7:1 to about 12:1, to give additional clearance. As an additional feature the vessel diameter can also be adjusted to create a "necked-down" region just below the gas outlet duct adjacent the top of the vessel to increase product gas velocity of the gas containing entrained salt particles, to prevent sticking of such particles to the vessel walls and restricting the gas outlet duct.

Abstract: A hot coke bed is established at the bottom of a vertical shaft furnace, e.g. an iron melting cupola. The cupola is then charged with alternate layers of ferrous metal and coke material, respectively. Burners burn hydrocarbon fuel in the presence of a stoichiometric excess of oxygen-enriched air and thus form a hot gas mixture including oxygen. The hot gas mixture passes upwards through the shaft of the cupola thereby providing sufficient heat to melt the ferrous metal. Molten ferrous metal flows downwards under gravity into and through the coke bed and may be removed through a tap hole. At least one jet of oxygen is injected into the hot coke bed so as to maintain it at a temperature sufficient to superheat the molten metal. Preferably a fan is operated to dilute with air the combustion gases above the level of the charge in the shaft and thereby create secondary flames. No air blast is supplied to the cupola.

Abstract: In a plant including a shaft, which, in its upper end region, includes a gas exhaust device and a charging arrangement for continuously charging bulk material, a temperature measuring device for measuring the temperature of the gas emerging from the bulk material is provided. In order to ensure the uniform treatment of the bulk material, i.e., a uniform gas passage through the same over the entire cross section of the shaft at little structural expenditures, several temperature measuring devices are provided in the upper end region of the shaft, distributed in a cross sectional plane, and the charging arrangement includes several tubular mouth pieces for forming at least one conical pile within the shaft, which are adjustable relative to the shaft cross section in the radial direction.

Abstract: Air is taken from the air compressor of a gas turbine including in addition to the compressor a combustion chamber and an expansion turbine. The gas turbine drives an alternator. The air taken from the compressor is cooled in heat exchanger to remove heat of compression therefrom. The air is separated in an air separation plant into oxygen and nitrogen. A stream of oxygen is withdrawn from the plant and used in a blast furnace in which iron is made. The off-gas from the blast furnace is a low grade gaseous fuel. It is compressed in compressor which has interstage cooling to remove at least some of the heat of compression. The compressed fuel gas is passed through the heat exchanger countercurrently to the air stream. The resulting pre-heated fuel gas flows into the combustion chamber of the gas turbine and is burned therein to generate gaseous combustion products that are expanded in the turbine. A nitrogen stream is withdrawn in the air separation plant.

Abstract: There is disclosed a method of starting a plant for the production of pig iron or steel pre-material including a direct-reduction shaft furnace and a meltdown gasifier.At first the still empty meltdown gasifier is heated up by aid of a combustible gas and the smoke gases forming are introduced into the still empty direct-reduction shaft furnace.Coke or a degassed coal product is charged into the direct-reduction shaft furnace and the smoke gases introduced into the direct-reduction shaft furnace are passed through the coke or the degassed coal product by releasing their sensible heat.The coke or the degassed coal product thereby is heated to ignition temperature and is charged into the meltdown gasifier in the hot state, catching fire upon the injection of an oxygen-containing gas or of oxygen.A further coal or coke bed serving for gasification is charged on the ignited bed of coke or degassed coal product and the charging substances are charged into the direct-reduction shaft furnace.

Abstract: A shaft furnace for melting copper solid into copper melt has been controlled by manual operation with reference to the actual storage quantity of the holding furnace so far. The burner air pressure of each zone of the shaft furnace is controlled by the actual storage quantity and the time change of it using Fuzzy Logic. The temperature of copper melt is adopted as another input signal. The proportion of burner air pressure of the zones is revised by the melt temperature. Automatic control basing upon the present invention decreases the fluctuation of storage quantity of the holding furnace.

Abstract: An apparatus for sealing an orifice is disclosed. The apparatus includes a shutter and an annular seat. The shutter includes a shutter body and a soft peripheral gasket. The shutter has a closed position in which the gasket is laid against the annular seat, in order to ensure sealing between a medium located on the same side of the seat at a given pressure and a medium located on the opposite side at a higher pressure. The seat is associated with the pressure compensator acting on the shutter in its opening direction under the action of a hydraulic fluid, the thrust of which is adjusted so as to correspond approximately to the force acting on the shutter in its closed position and resulting from the pressure differences prevailing either side of the shutter.

Abstract: A plant for metallurgical treatments, in particular for melting or melt-reducing metals, metal compounds and/or metal alloys, or for producing calcium carbide, comprises a shaft receiving a burden, a melt collecting space disposed laterally of, and below, the shaft, as well as at least one burner arranged laterally of the shaft. In order to enable the accurate process control of the metal melt and the controlled smelting of the burden, the burner is arranged in a combustion space connecting the lower shaft end with the melt collecting space and designed as a plasma burner. The combustion space is located at a level above the melt collecting space and including a combustion space bottom, which is plane, or preferably rises, relative to the shaft and enters into the melt collecting space by an overflow edge that separates the metal melt from the burden.

Abstract: Expansive forces in a furnace of cylindrical shape (e.g. a ladle furnace) are absorbed by means of a metallic ring positioned in the bottom of the furnace which substantially fits the inner, lower side wall of the cylindrical steel shell of the furnace and absorbs the expansive forces directed against this side wall.

Abstract: A method of desulfurizing iron in a plasma fired cupola having a plurality if feed nozzles each of which have a particulate feed and a plasma torch connected thereto; a fluxing agent such as CaO, MgO, CaCO.sub.3, MgCO.sub.3 or CaCO.sub.3 MgCO.sub.3 is fed to the feed nozzle and melted by the plasma torch; the molten fluxing agent mixes directly with the molten iron in the cupola and reacts with the sulfur in the iron; the reacted and unreacted fluxing agent combine with the slag reducing the viscosity making the slag flow better and producing a low sulfur iron in the cupola.

Abstract: A bottom construction for a shaft furnace, has a plurality of horizontal layers of refractory material, and a gastight metal membrane located above at least the lowest layer of refractory material. So that the membrane is easily constructed, can accommodate thermal movements and has a level upper surface, the layer of refractory material immediately underneath the metal membrane is formed of blocks and has a level top surface and the metal membrane is formed of loosely laid, mutually abutting metal plates which are stacked in at least three layers. The pattern of the joints of the plates of each of these three layers is offset, as seen in plan view, with respect to the pattern of the joints of both the other two layers. The plates may be copper sheets. The membrane may have a peripheral flange cemented in a slot at the furnace wall.

Abstract: A process for melting metal in a shaft furnace operated without coke using a liquid or gaseous fuel, whose combustion products initially heat the molten metal which has collected below the furnace hearth (2) in furnace shaft (1) to the desired tapping temperature, followed by the introduction thereof into the furnace shaft for melting the metal. Furnace shaft and furnace hearth are separated by a water-cooled grid (6), which carries the charge introduced into the shaft. The flame temperature of burner (3) is controlled through preheating the combustion air. The combustion air is recuperatively heated by the waste gases of the shaft furnace. The heat transfer in the recuperator (4) is variable and can be influenced by the supply of cooling air to the waste gases prior to recuperation, by a controllable induced draft blower behind the recuperator and/or after-burning of the waste gases prior to the introduction thereof into the recuperator.

Abstract: A method of injecting burning resistant fuel into a blast furnace, which includes the steps of supplying a hot blast air having a temperature of at least 810.degree. C. into a blast furnace, injecting the burning resistant fuel into the hot blast air, and injecting a gas fuel into the hot blast air independently of injection of the burning resistant fuel. The gas fuel is supplied to an outer peripheral area of the burning resistant fuel. The injection of the gas fuel is in a proportion of at least 2% of the injection of the burning resistant fuel in terms of calorific value.

Abstract: The invention concerns a method for in particular repairing the region of the pouring apertures of a blast-furnace which mainly comprises employing a support element (10) independent of the casing (3) and on which bear the blocks (17) of refractory material. The support element (10) is first of all positioned relative to these blocks and then fixed in the final position relative to the casing (3), after which there is welded around the support element (10) and to the casing a sheet of metal which provides the seal between the support element and the casing.

Abstract: A method and apparatus for simultaneously separating volatile metals, including zinc and lead, and non-volatile metals, including copper, from mixtures of metallic and metallic oxide. Finely pulverized metal containing material, is continuously fed into the reactor chamber along with pulverized carbonaceous material, such as coke, and also oxygen or air. The reactor chamber is intensely heated by a transferred arc plasma generator to provide sufficient heat energy which together with the reducing gases cause a reducing reaction and melt the non-volatile copper and other metals which form a puddle upon the floor of the reaction chamber and to form a layer of slag covering the puddle, and simultaneously to vaporize the volatile zinc, lead and the like metals.

Abstract: In a shaft furnace having a metal shell, a refractory lining of relatively high thermal conductivity and cooling bodies which project inwardly through the shell into the lining and through which in operation cooling liquid flows, has a high uniformity of temperature in the lining. In order to improve its operational characteristics, in particular to improve temperature uniformity yet further while reducing heat loss, the shell and the cooling bodies are screened from the lining. Between the cooling bodies and the refractory lining and between the shell and the refractory lining there are respectively first and second thin layers of refractory material having in each case a .lambda.-value of less than 5 kcal/mh .degree.C., preferably less than 1.5 kcal/mh .degree.C. The thin layers may be of refractory felt or refractory plates.

Abstract: In a shaft furnace having a metal shell, a refractory furnace lining inside the shell and a taphole construction comprising a drilled taphole extending through a plug located in an aperture in the shell and a taphole brick structure forming part of said furnace lining, the taphole brick structure at least partly consists of at least one taphole brick of high thermal conductivity material selected from the group comprising graphite, semi-graphite and material of equivalent heat conductivity, there further being screening means comprising material of substantially lower heat conductivity coefficient than graphite and semi-graphite located between said taphole brick and said furnace shell.

Abstract: A treating furnace for manufacturing non-fired iron-bearing pellets comprising a green iron-bearing pellet inlet at one end thereof and a non-fired iron-bearing pellet outlet at the other end. Green iron-bearing pellets are continuously fed into the treating furnace through said inlet and after being heated are discharged through said outlet. The treating furnace contains at least one heating gas blowing port for blowing heating gas into the furnace and at least one heating gas discharge port for discharging said gas after it has heated the pellets. The furnace also contains a preheating zone and at least one preheating gas blowing port and at least one preheating gas discharge port to pass preheating gas through said preheating zone. The heating gas discharged from the heating gas discharge port is used as the preheating gas.

Abstract: In a shaft furnace for burning limestone or similar raw materials, gaseous, liquid or solid fuels are supplied through fuel supply pipes to the burning zone of a furnace shaft. To permit the simultaneous supply of at least two different fuels, the fuel supply pipes are arranged as multiple fuel lances. The fuel lances extend inwardly from the shaft furnace wall through the preheating zone into the first part of the burning zone. The fuel lance is a double tube member made up of an inner tube laterally enclosed by an outer tube forming an inner fuel supply passageway and an outer annular fuel supply passageway. Two separate fuels can be introduced into the burning zone, one flowing through the inner passageway and the other through the outer annular passageway. The two different fuels can be supplied in varying proportions without any changeover operations.

Abstract: Apparatus for discharging hot flowable solids comprises conical conveyor screws, which are arranged to form a star-shaped array and contained in respective conveyor troughs and at their inner ends are rotatably mounted in a centrally disposed hollow body. In order to ensure a gas-tight seal of the furnace and to permit a simple replacement of the conveyor screws, the conveyor troughs and the centrally disposed, open-bottomed hollow body are constituted by a bottom structure, which is adapted to be flange-connected to the shell of the furnace. The largest depth of each conveyor trough is at least as large as the largest outside diameter of the associated conveyor screw. Each conveyor trough is closed at its outer end by an end wall, which carries a discharge housing, which contains the outer end of the associated conveyor screw and carries a discharge fitting.

Abstract: In a cast house of a blast furnace, one or more movable exhaust hoods, connected to exhaust ducts, are provided for extraction of gas and dust. In order to provide such a hood which is easily moved manually by the operating personnel but which, with its duct, nevertheless does not unduly obstruct the working space, the hood is carried by a swivellable duct section which is connected to a fixed duct section at its swivelling axis and is supported, in cantilever fashion, by a bearing, e.g. a ball bearing, which is located outside the duct and extends circumferentially around the duct.

Abstract: An apparatus for equalizing the pressure in shaft furnaces which are operated at a pressure in excess of atmospheric pressure. At least one storage bin is connected to the furnace chamber, although isolated from the atmosphere and the furnace chamber by sealing valves. A gas pipeline serves to selectively supply or exhaust gas to the storage bin to equalize pressure. In one embodiment of the invention, two storage bins are interconnected by a gas pipeline and appropriate valves for equalizing pressure between the storage bins.