1147results 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.

The present invention is furnace lining repairing process, and is especially the furnace lining repairing process for steelmaking IF furnace. The furnace lining repairing process includes the following steps: determining repairing time, clearing furnace inside, applying adhesive and furnace building material, setting forming steel mold and starting mold block, applying furnace building material, and sintering furnace building material. The furnace lining repairing process is relatively simple, and has effective repair of furnace lining, organic combination of the repair material and original furnace building material, flat furnace bottom, homogeneous heating of the hearth, good sintering effect and long service life of the repaired furnace lining.

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.

The invention provides a method for overhauling a fire-resistant material for an annular air duct and a chute in a coke dry quenching furnace. A furnace body is divided into a pre-storage chamber, the annular air duct, a chute area and a cooling chamber; and brick supporting rib plates and expansion seams are arranged on a pre-storage section and the annular air duct. The method is characterized by comprising the following steps of: a, erecting a protection platform in the furnace and preparing construction equipment; b, erecting a scaffold for taking apart bricks; c, dismounting a part of the chute and the annular air duct; d, cleaning the furnace; e, constructing the chute; f, constructing the annular air duct; and g, dismounting the scaffold and igniting to bake the furnace. The method for overhauling the fire-resistant material for the annular air duct and the chute in the coke dry quenching furnace provided by the invention has the advantages of reasonable design of construction step, simplicity in operation, safe and reliable engineering quality, and reduction of the engineering construction cost.

The invention provides a welding repair material for repairing a coking furnace and a method for repairing the coking furnace. The welding repair material comprises the following components in percentage by weight: 1-3% of metal aluminium powder, 5-8% of metallic silicon powder, 2-5% of mineralizing agent, 65-85% of silica fume or quartz powder and 10-20% of quartz sand. The method for repairing the coking furnace comprises the steps of spraying the welding repair material for repairing the coking furnace onto a wall brick surface of a high temperature furnace to be repaired along with an oxygen-enriched gas and carrying out an oxidation reaction, so that the welding repair material is partially molten and adhered on the wall brick surface of the coking furnace to be repaired, and a ceramic repairing layer is formed. The welding repair material for repairing the coking furnace has the advantages that secondary resources such as coal ash and silica fume are taken as raw materials, high-efficiency comprehensive utilization of the secondary resources is realized, and production cost of the welding repair material is reduced; besides, aluminium and silicon metals are added, so that spontaneous heating sintering is realized, and no high temperature high pressure gas is adopted when the welding repair material for repairing the coking furnace is adopted for repairing the coking furnace; content of silica in the welding repair material for repairing the coking furnace is more than 90%, so that the welding repair material for repairing the coking furnace is a highly silicious welding repair material and has a good silica brick breaking effect when being used for repairing the coking furnace.

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.