507results about "Linings repair" patented technology

A metallic resistive heater and a method of production are described. The resistive heater has a metallic component that is electrically conductive (i.e. has low resistivity) and an oxide, nitride, carbide, and or boride derivative of the metallic component that is electrically insulating (i.e., has high resistivity). The resistivity is controlled by controlling the amount of oxide, nitride, carbide, and boride formation during the deposition of the metallic component and the derivative.

A method is disclosed to produce a heat pipe with a sintered powder wick formed inside the heat pipe. The method employs tape-casting technology to firstly produce thin sheets of powder and then these sheets are sintered to form the wick. In the tape casting procedure, a slurry of the powders necessary to construct said wick is cast onto a moving surface to form a slurry layer and then the slurry layer is dried to form a green tape. The green tape is rolled onto a mandrel and then is inserted into a hollow casing and sintered to cause the powders in the green tape to diffusion-bond together. Thus, the sintered powder wick is constructed.

According to the invention, a method for identifying and determining die position of a metallurgical vessel for measuring its fireproof lining using electromagnetic radiation, an operator is defined in relation to a two or three dimensional structure with a known shape and size. Distance values and corresponding measuring angles are determined in the area of the structure and measured distance value and corresponding measuring angles are used to scale the operator. The dimension and resolution of the operator in the pixel coordinates system and the anticipated values of the operator are adapted to the measured polar coordinates. A result value is then formed from the differences between the anticipated values of the operator and the measured values and the location of the structure that is sought is determined from the position of the minimum result value.

A modular oven, such as a batch process oven, having a standardized set of self supporting, interconnectable panels which, when assembled, from a self-supporting heat containment shell, free of added structural support members. Also described are the self-supporting modular oven panels themselves having common roof, sidewall and end wall shell configuration and a method of assembling the panels such as in the expansion or conversion of a first modular oven assembly to a second assembly more conducive to current production requirements.

An inner lining for the steel shell of a carbothermic reduction furnace for the production of alumina has a base layer of graphite and a coating layer of refractory material. The refractory material is corundum (Al₂O₃) bound by Sialon (Si.Al.O.N). The lining structure provides protection against the molten slag and it is not attacked by the CO-rich melt furnace atmosphere. Further, the lining does not contaminate the melt and it provides an effective heat dissipation system in case of a power shut-off.

An on-line method and a device for cleaning of contamination such as caking or slag deposits from surfaces in vessels and combustion installations by means of blasting technology. An explosive gas mixture is made to detonate in the proximity of the deposits and thereby clean the deposits from the surfaces.

A venturi vent assembly for an outdoor cooker includes a cooker mounting flange attached to, and surrounding, one end of an outer tube. An inner tube extends through the outer tube and has an blower inlet at one end and an outlet. A plurality of ribs attach an exterior surface of an inner tube to an interior surface of the outer tube to define a plurality of venturi passages that surround a center passage of the inner tube. A valve plate is mounted on the inner tube and is movable between a closed position in contact with the outer tube to close the venturi passages, and an open position out of contact with the outer tube to open the venturi passages. The outlet tube of an electric blower may be mated to the inlet of the inner tube, and the venturi of assembly may be attached to a firebox of an outdoor cooker via the mounting flange.

A subject for the invention is to provide an unshaped refractory composition having not only high thermal resistance but also improved corrosion resistance and improved unsusceptibility to slag infiltration.

The invention is “an unshaped refractory composition comprising: (1) 20 to 70% by weight raw spinel material comprising an MgO—Al₂O₃ spinel phase and containing 2 to 20% by weight magnesia and/or raw spinel/corundum material comprising an MgO—Al₂O₃ spinel phase and a corundum phase and containing 2 to 20% by weight magnesia; (2) 3 to 12% by weight raw magnesia material having a particle diameter of 0.3 mm or smaller, containing particle sizes of 75 μm or smaller in an amount of 55 to 85% by weight, and having a magnesia purity of 90% by weight or higher; (3) 3 to 10% by weight alumina cement having a calcia content lower than 20% by weight; (4) 0.3 to 1.5% by weight ultrafine powder consisting mainly of silica; and (5) a raw alumina material as the remainder”.

The invention relates to a wet process for building a 3t intermediate frequency electric furnace. By the process, 3t of materials can be melted, and the service life is prolonged. The process comprises the following steps of: (1) manufacturing a steel crucible die which has a shape of a truncated hollow cone; (2) paving an insulation layer and a thermal insulation layer by using two layers of asbestos cloth; (3) paving a furnace bottom, namely paving two layers of asbestos cloth at the furnace bottom in a staggered mode; (4) paving a furnace wall, namely paving two layers of asbestos cloth next to the inner wall of an induction coil from top to bottom, ensuring that each layer is flat and does not have any wrinkle, adhering longitudinal joints for lapping by using water glass, staggering joints of two adjacent layers, and adhering the asbestos cloth which stretches out of the upper plane to a fireproof brick plane at an upper opening of the furnace by using the water glass; (5) preparing a furnace lining material from refined quartz sand; (6) manually knotting a furnace lining, brushing a layer of water glass before filling, and tamping a filler; and (7) baking the furnace and sintering, namely baking only by using firewood after the furnace is built by the wet process, adding 50 to 60kg of firewood into a hearth for several times, and completely combusting to bake the furnace lining.

A film for preventing a refractory deterioration is formed on the surface of refractory for a refuse incinerator. Since the preventive film exhibits high adhesion resistance to clinker generated in the incinerator, clinker does not adhere to the film easily. Since the preventive film is composed of fine and dence inorganic oxide based ceramics, surface layer of a brick body is covered with a film harder than the body. Consequently, wear resistance of refractory brick is enhanced. Since a corrosion resistant film exists on the surface of the body, intrusion of chloride gas is suppressed effectively, even if the body is exposed to chloride gas. Even an inexpensive fireclay brick is protected against adhesion of clinker and spalling, and use period of refractory brick is prolonged.

A process for forming a silicon nitride-bonded silicon carbide honeycomb monolith by a) forming a plasticizable mixture which includes (1) about 60% to 85% by weight, powdered silicon carbide with a median particle size of about 10-40 micrometers; (2) about 15% to 40% by weight, powdered silicon metal with a median particle size of about 5-20 micrometers; and, (3) organic components; b) extruding the plasticizable mixture to form a green honeycomb monolith; c) drying the green honeycomb monolith; and, d) heating the honeycomb monolith to 1450.degree. C. with a hold of 1 hour in an atmosphere of argon; and, e) nitriding the honeycomb monolith between 1450.degree. C. to 1600.degree. C. for a time sufficient to obtain a silicon nitride-bonded silicon carbide body.

The invention relates to a 0.5-1 ton intermediate frequency furnace building technology based on a wet method. The technology is characterized by comprising the following steps: a. cutting asbestos cloth according to the dimension of an electric furnace, and preparing a quartz sand mixing material according to the size of an intermediate frequency furnace; b. distributing the asbestos cloth which is cut in advance from top to bottom on a coil in a furnace-body-type cavity to be built; c. knotting for the bottom of the furnace; d. mounting a steel pot model; e. knotting for a furnace wall; f. knotting for the top of the furnace; g. knotting for a water outlet groove; and h. drying the furnace. According to the invention, the flow is reasonable, the operation is simple, and the production cost is low; after the quarts sand is stirred and mixed by use of an appropriate amount of water, the adhesivity is stronger, feeding and knotting are convenient and simple, the furnace liner has high degree of compacting, the service life of the furnace is improved, the service life of a 1 ton intermediate frequency furnace is prolonged to 15-25 days, the service life of a 0.5 ton intermediate frequency furnace is prolonged to 80-90 days, the steel pot can also be extracted in the process of drying the furnace and can be used again, and the economic benefit is obvious.

The invention discloses a kind of improved converter fast-burning heat-junction free-running patching material, its manufacture technology and application. Its features are: the patching percent by weight is one of the two followed: (1) MgO 75-85 Al2O3 1.0-2.0, whole carbon 4.0-12.0 Fe2O3 0.5-1.5 CaO 1.0-2.5, the remnant is SiO2; (2) Mg0 60-70 Al2O3 0.5-2.0, whole carbon 4.0-12.0 Fe2O3 0.3-1.0 CaO 10.0-20.0, the remnant is SiO2. Its manufacture technology is: firstly, to weigh according the above mixture ratio and then to put it in high-temperature bonding agent, high-temperature lacquer solvent, detonation suppression and anti-oxygen, then to intermix it homogeneously by the efficient mixing machine and to deliver it to junk machine by the band carrier to press compact, after all, press it to balls by the ball forming mill. The life span of the heat-junction free-running patching material this invention offers is the time for 30-50 furnaces, and the time for sintering is lowed to 10-25 minutes. It has the merits of good heat flow, high bond strength, high erosion-resisting characteristics and anti osmosis and good sintering under low and middle temperature, and we have gotten good result in the 300-ton converter in Baogang steel works.

An apparatus for treating, in particular purifying or degassing, molten metal (40), comprising a component (10) exposable to molten metal to be treated and means (13) for imparting a rotary motion to the molten metal (40) about a substantially vertical axis. The apparatus is so arranged that during use at least part of a wear-exposed surface of the component (10) is temporarily or permanently in contact with molten metal (40), the contacting molten metal being in motion relative to the wear-exposed surface. The wear-exposed surface is coated with a slurry-applied protective coating (18A,18B) of refractory material in a heat stable binder, in particular an inorganic colloidal and/or polymeric binder, protecting the wear-exposed surface against erosion, oxidation and corrosion.

A coke-oven repairing apparatus comprising: a traveling carriage 3 which travels in the direction of coke oven battery with the carriage straddled on the rails placed on the top of a coke oven; a traversing carriage4 provided on said traveling carriage 3, which moves in the direction orthogonal to the direction of coke oven battery; and a working device 5 for making repairs on the oven walls within the coke oven which is mounted on said traversing carriage 4,

wherein the working device 5 includes: a guide post 31 which stands on the traversing carriage 4, and is also coupled, at its lower end portion, to a supporting portion provided on the traversing carriage through a pivot shaft 42; a lance 32 which ascends or descends along the guide post 31; and a derricking device 45 which tilts the guide post 31 between a forward-tilted posture and a backward-tilted posture using the pivot shaft 42 as the fulcrum to oscillate the lance 32 inserted in a coke-oven carbonizing chamber through a charging-hole, within the carbonizing chamber.

The invention discloses a construction method for patching of refractory materials of a furnace top of a heating furnace. The construction method belongs to the technical field of metallurgical production equipment, and is low in investment cost. Service life is long after construction is completed. The construction method for patching includes steps of stopping the furnace and reducing the temperature of the furnace to be lower than 45 Celsius degree; erecting furnace top supporting frames: erecting the furnace top supporting frames in areas, which are required to be repaired, of the furnace top in the furnace, and supporting the furnace top firmly; digging repair slope surfaces: digging away refractory materials of the furnace top required to be repaired due to cracking and dropping, and forming the repair slope surfaces on peripheries of the repaired areas; erecting mold plates: erecting the pouring mold plates under the furnace top after the refractory materials of the furnace top are dug away and the repair slope surfaces are formed, and forming repaired spaces; pouring and maintaining refractory pouring materials: pouring the refractory pouring materials which are mixed and qualified in the repaired spaces and maintaining the refractory pouring materials for three days at least; and removing the mold plates: removing the pouring mold plates and the various supporting frames and recovering production.

The invention relates to a furnace building method of an intermediate-frequency induction furnace for copper alloy smelting, which comprises the following steps: firstly, preparing a lining material of a furnace-body outer lining and a fire-door lute, and laying a layer of epoxy plate and placing an induction coil on an asbestos board base; laying a glass fiber fabric on the inner wall of the induction coil and the epoxy plate, so that the glass fiber fabric is formed into a pocket shape; hierarchically adding the lining material of the furnace-body outer lining into the glass fiber fabric pocket, and hierarchically tamping and knotting the obtained product so as to form a furnace bottom; then, placing a graphite crucible on the midmost position of the furnace bottom and compacting the furnace bottom; hierarchically adding the lining material of the furnace-body outer lining into a space between the glass fiber fabric bag and the graphite crucible, and tamping and knotting the lining material so as to obtain the furnace-body outer lining, so that the top surface of the furnace-body outer lining is lower than the top surface of the graphite crucible and the top surface of the induction coil; adhering a fire door to the top surface of the graphite crucible through the fire-door lute, filling the fire-door lute between the fire door and the glass fiber fabric bag, and carrying out tamping and flattened-brushing on the fire-door lute so as to obtain a fire-door outer lining; carrying out sintering on the outer lining by using an oven, so that silica has crystal transformation; and after the whole furnace is hardened, stopping heating so as to complete the furnace building. The method disclosed by the invention has the characteristics of high strength, good furnace-body combined performances and long service life.

A method of injecting oxygen into a melt located within a metallurgical furnace having a heated furnace atmosphere in which oxygen and fuel is injected into 1 or more nozzles having passageways of converging-diverging configuration under choked flow conditions to produce supersonic jet or jets discharged from the passageways. Fuel is injected into internal circumferential locations of the passageways so as to impart a structure to the jets being discharged that have an outer circumferential region containing a mixture of fuel and oxygen and a central region containing essentially oxygen. Such a structured jet upon discharge interacts with the furnace atmosphere to create an outer shear-mixing zone in which the outer circumferential layer mixes with the heated furnace atmosphere and auto-ignites to produce a flame envelope surrounding a supersonic jet of oxygen. The jet of oxygen and flame envelope can be directed against a melt contained within the metallurgical furnace for injection of oxygen into the melt.

The invention relates to a grouting method for a blast furnace, aiming to enhance the grouting success rate of the blast furnace. In the invention, the temperature of a furnace shell of the blast furnace is measured by using infrared imaging scanning and an infrared temperature measuring instrument to find out the position with relative high temperature; the position is taken as a datum point, holes are bored at vertical or transverse interface parts between two cooling walls or among three cooling walls which are adjacently installed at the upper side, the lower side, the left side and the right side; a hollow drill is used to drill through the furnace shell firstly, then drill through fillers between the furnace shell and the cooling wall, continuously drill a hole forwards to drill through the cooling wall, and then drill through unshaped ramming materials or pouring materials between a brick lining and the cooling wall; a drilling channel is cleaned; a grouting channel is dredged,lubricated and preheated; and an amount upper limit value of grouting is controlled to be 60 kg to 120 kg; proper grouting pressure is ensured, when the brick size of the brick lining is small and isnot provided with a brick locking groove, the grouting pressure is relative low to be generally controlled to be 1.0 MPa-1.5 MPa, and when the brick size of the brick lining is large and is provided with the brick locking groove, the grouting pressure is relative high to be generally controlled to be 1.0-3.0 MPa.

The present invention relates to a method for repairing a protective lining of an industrial reaction or transport vessel, such as a converter vessel, electric arc furnace, or ladle. The method comprises identifying combined areas of the lining having a thickness below a predetermined threshold value by means of a measuring device, which measuring device measures the residual thickness of the lining and a processing unit, which processing unit in a first step transforms the residual thickness data into binary data, by comparing the measured residual thickness data with the predetermined threshold value for the thickness of the lining, and assigning the binary value “1” to areas of the lining having a thickness below the pre-determined threshold value, and the binary value “0” to areas of the lining having a thickness equal or higher than the pre-determined threshold value, or vice versa, in a second step combines isolated areas of the lining having a thickness below the predetermined threshold value into combined areas of the lining to which the binary value for areas of the lining having a thickness below the pre-determined threshold value is assigned, and in a third step computes the position and repair sequence of each of the combined areas and transfers these data to a repair device, and applying monolithic lining material onto the combined areas computed by the processing unit by means of a repair device.

The invention relates to a construction method for manufacturing a working layer of an annular heating furnace by utilizing timber shuttering and profile steel. The construction sequence of the method is sequentially a furnace wall, a furnace top and a furnace bottom of the working layer of the annular heating furnace; the furnace wall comprises an inner annular wall and an outer annular wall, wherein the furnace wall construction method comprises the following steps: 1, the processing and manufacturing of the timber shuttering; and 2, erection of a framework and casting: (1) measuring and wire laying; (2) establishment of a timber shuttering supporting system; 3, erection of the framework; 4, casting and vibration guiding; 5, maintenance and shuttering detachment; 6, maintenance; and 7, roasting the maintained working layer till dryness; after the roasting, the molding of the cast furnace wall of the annular heating furnace is completed; the timber shuttering of the furnace wall of the whole annular heating furnace is turned over for three times; the construction temperature in each time is 120 DEG C; and the turnover of each time is cast for 5 to 7 layers. The construction method is simple, has good molding quality, short construction period and low cost and is the construction method for manufacturing the working layer of the annular heating furnace by utilizing the timber shuttering and the profile steel capable of reducing the labor intensity.

The invention relates to a remote control converter wet spraying process method and a remote control converter wet spraying device. A continuous mixer is adopted to stir a material by adding water in advance; the stirred material is high in fluidity; the material continuously enters a self-flow material distribution device, then is uniformly conveyed into a material conveying pipeline by the distribution device, and is blown out by a high-pressure gas; one end of the conveying pipeline is connected with a high-pressure gas supply, and the other end of the conveying pipeline is connected with a spray gun; an accelerating agent is introduced from a part close to the spray gun; the forward movement, the backward movement and the rotation of the spray gun and the forward movement, the backward movement and the steering of a spray repair vehicle can be finished by remote operation; and a water-cooled protector is arranged outside the spray gun to prevent the spray gun from being damaged by high temperature. Compared with the prior art, by using the method and the device, the operating time is shortened by at least 20 percent, and unexpected losses of materials can be reduced; moreover, the method and the device are favorable for environmental protection of operation regions, and are particularly suitable for maintenance repair of the converter.

An energy-saving cement rotary kiln inner liner and a masonry process thereof belong to the field of structures and constructions of rotary kiln inner liners. The energy-saving cement rotary kiln inner liner comprises a kiln body, wherein an inner liner layer is attached to the inner wall of the kiln body, the energy-saving cement rotary kiln inner liner is characterized in that the inner liner layer is formed by constructing prefabricated bricks and casting materials at intervals; each prefabricated brick comprises a working face body and a non-working face body, low heat conduction thermal insulating layers are respectively embedded into the non-working face bodies of the prefabricated bricks and the casting materials, and the low heat conduction thermal insulating layers inside the non-working face bodies and the low heat conduction thermal insulating layers in the casting materials are distributed in a staggered manner inside the kiln body. A rotary kiln prepared through the energy-saving cement rotary kiln inner liner provided by the invention is wear-resistant, energy-saving and durable, and also can prevent the occurrence of fire spurting, the thermal insulation performance is high, and the service life is long. The rotary kiln is more environment-friendly, does not cause pollution to the environment, and is convenient in masonry construction and high in quality.

This invention relates to a lining for induction furnaces, and more specifically a lining for coreless induction furnaces. A flexible lining material (10) for lining an induction furnace (1) has a laminated structure comprising metal foil (12) and at least one heat-resistant supporting layer (14). The incorporation of a very thin metallic foil layer (12) in the lining material (10) creates a vapour barrier preventing vapours such as zinc from reaching the induction coil (4) of the furnace. The lining material (10) is designed so that the metal foil (12) is not significantly affected by the induction fields during the operation of the furnace.

The invention discloses a dismantling method of refractory materials, and particularly relates to a method for dismantling refractory materials at the arch crown of a hot blast stove, which is high in construction speed, and simple and convenient to implement. According to the characteristics of self-weight falling and mutual extruding and locking function of the refractory materials at the arch crown, stopper bricks are dismantled first, and then an impact bar acts on refractory bricks on the arch crown from bottom to top, so that the refractory bricks at the arch crown move upwards to break away from self-weight falling and mutual extruding and locking states and fall off naturally; and after the refractory bricks fall off,a heat-insulation refractory material layer can be easily removed, and simultaneously, all operators only need to stand on a steel platform at the top of the hot blast stove, therefore, potential safety hazards cannot be caused when the refractory bricks fall into the hot blast stove. Compared with the conventional manner of cracking the refractory bricks, the method directly damages the extrusion locking between the refractory bricks at the arch crown, and does not need to crack the refractory bricks, thereby greatly reducing the workload and reducing a great quantity of work.

The invention discloses a furnace top repairing method for a heating furnace, which belongs to the field of metallurgy industry. The method comprises the following eleven steps: making a furnace top pressing hoisting beam and a support seat; making an anchor clamp and a hanging anchor brick; erecting a scaffold on the damaged part of the furnace top in the heating furnace body; removing the refractory material layer and a steel-structure hoisting beam on the damaged part of the furnace top; mounting the steel-structure hoisting beam of the damaged part of the furnace top; leveling with a line and laying a line on the steel-structure hoisting beam of the damaged part of the furnace top; welding and fixing the anchor clamp; mounting the hanging anchor brick; arranging an inner mould of the pressed part of the heating furnace; arranging an outer mould; pouring refractory material; and maintaining the refractory material for 24 hours. Through the invention, the phenomenon that the refractory material on the furnace top falls and drops due to big cracks and the like is avoided, and consequent furnace top fire and even major accident of forced stop of the furnace are prevented; the accident or trouble shooting period for the furnace top of the heating furnace is shortened to 11 days from 20 days; and the service life of the furnace top can be increased to more than 10 years from 5 years before.

An aluminium-wettable protective coating on a substrate, for use at elevated temperature in an oxidising and/or corrosive gaseous and/or molten environment is disclosed. The coating (20A, 20B, 20C, 20D) is applied to protect the substrate (5, 15, 16) from liquid and/or gaseous attack. The coating comprises particles of at least one metal oxide and/or at least one partly oxidised metal in a dried and/or cured colloidal carrier and/or organic binder. The metal oxide and/or partly oxide metal is reactable with molten aluminium when exposed thereto to form an alumina matrix containing metal of said particles and aluminium. The coated substrate (5, 15, 16) may be used in an aluminium electrowinning cell an arc furnace for the recycling of steel or an apparatus for the purification of a molten metal such as aluminium, magnesium, iron or steel.

Disclosed is a method and apparatus for spray application of a monolithic refractory material, designed to add water to a powder material and knead the powder material during feeding. In the method and apparatus, a primary water injector 7 is arranged in a feed hose 5 extending from a spray-material supply device 1 to a distal spray nozzle 4, and a secondary water injector 8 is arranged in the feed hose at a position just before the distal spray nozzle 4. The primary water injector 7 is arranged on an upstream side of the secondary water injector 8 with a given distance therebetween. 10 to 50 mass %, preferably 15 to 40 mass %, of application water on the basis of the total application water required for the spray application is added from the primary water injector together with compression air in the form of water particles having an average particle size of 100 μm or less, to evenly wet a spray material during feeding to the extent capable of preventing the spray material from being slurried. Then, the remaining application water is injected from the secondary water injector together with compression air. The spray application method and apparatus of the present invention can achieve a high kneading effect by a low amount of application water while improving operational efficiency.

The binder for monolithic refractories according to the present invention includes SrAl₂O₄; SrAl₂O₄ and 5 mass % or less of the remainder; or a mixture of SrAl₂O₄ and Al₂O₃.

The invention relates to a neutral lining of a medium-frequency induction furnace for smelting of a sintered neodymium-iron-boron permanent-magnet material, which is manufactured through the following steps: proportionally mixing high-alumina bauxite chamotte used as a main raw material and added magnesia powder and admixture, uniformly stirring, ramming and baking. The neutral lining obtained by the invention has the characteristics of high refractoriness, excellent chemical property stability and volume stability, favorable thermal shock resistance, convenient and quick furnace building process, short furnace baking time, long furnace life, low comprehensive cost and the like.