Abstract: A fired precast block prevents itself from dropping off early due to corrosion and increases service life of a blast furnace runner, etc. when used in a very vulnerable portion of the blast furnace runner, etc., and can be produced at low costs. The fired precast block has an upper surface to contact molten metal or slag, a lower surface opposing the upper surface, and a plurality of side surface. The fired precast block is used by being embedded in a castable in such a manner that the upper surface is exposed from the castable and the lower surface and the plurality of side surfaces contact the castable. Each side surface of at least one opposing pair of side surfaces includes a planar portion and an uneven portion. The uneven portion has at least one groove-shaped concave portion.

Abstract: A fluidized bed system having a containment vessel, a precast and predried monolithic refractory floor module positioned in the vessel, and a plurality of precast and predried monolithic refractory wall modules stacked within the vessel. The plurality of wall modules includes a first wall module is positioned on the floor module, wherein the floor module and the first wall module have interlocking surfaces, and wall modules adjacent to one another have interlocking surfaces. A method for assembling a fluidized bed reactor is also provided.

Abstract: Embodiments of the invention comprise a preheater for preheating a ladle for use in steelmaking wherein less fuel is consumed in heating the ladle efficiently and accurately to a controlled temperature. A preheater temperature is varied by controlling a burner of the heating unit based on measurements of refractories of the ladle taken by a pyrometer. The heating unit of the preheater includes an emissive coating for reducing heat loss and efficient heating during the preheating process. The heating unit of the preheater also includes valve mechanisms for accurately varying a flame size of the burner by regulating the rate of fuel, air, and oxygen supplied to the heating unit.

Abstract: A furnace comprises a cage holding and supporting an insulation pack comprising one or more base boards, one or more top boards and a plurality of side boards each of rigid carbon fiber based insulation material, the one or more base boards, one or more top boards, and plurality of side boards defining a cavity between them. A flexible carbon felt is disposed between the side boards and the cage.

Abstract: A cracking furnace construction includes a firebox defining a chamber having a high emissivity thermal protective coating disposed on at least part of the refractory walls and/or on process tubes disposed within the chamber. The coating contains an inorganic adhesive for metal/alloy tubes or colloidal silica and/or colloidal alumina for refractory walls or ceramic tubes, a filler, and one or more emissivity agents. A method of coating the firebox chamber includes preparing the surface of the tubes/refractory walls, preparing the coating, and applying the coating to the surface.

Abstract: A kiln of the pottery or glass type and of insulating firebrick or ceramic fiber with an interior wall includes: a ceramic holder for holding a wound electrical heating element; a channel in the interior wall for receiving and supporting the ceramic holder. The ceramic holder is removably positionable within the slot with means for receipt and holding the wound electrical heating element when the ceramic holder is positioned within the channel in a first preferred embodiment, the ceramic holder has a supporting surface for receipt of the heating element and an inner, upper lip for holding the heating element on the ceramic holder. The interior wall has a horizontal retaining slot aligned with the ceramic holder supporting surface, the supporting surface has an outer end received within the retaining slot and an inwardly angled bore and a pin passing through the bore into the interior wall for holding the ceramic holder removably in place.

Abstract: A fixture (30) adapted to permit the heated exchange of a liner (14) from an operating vertical furnace (10). The fixture is adapted to secure to the base of the liner (14) to both unlock and lower the heated liner, such as a silicon carbide liner, at an controlled rate. The fixture is also adapted to elevate a new liner into the operating vertical furnace at a controlled rate to control the rate of heating of the liner as it is inserted into the operating vertical furnace. The fixture includes an inner ring (34), a low-friction Teflon® ring (36), and an outer ring (38) permitting the rotation of the inner ring within the outer ring. Advantageously, the low friction ring comprises a flanged portion and a vertical portion allowing rotation of the inner ring within the outer ring even when elevated at extreme temperatures exceeding 500° C.

Abstract: A carbon baking furnace having spaced-apart, hollow flue walls defining a soaking pit therebetween. Each of the flue walls is formed of refractory bricks and has a pit face facing the pit and a flue face facing an inner flue gas passage. A coating is provided on the pit face of the flue walls. The coating increases the emissivity value of the pit face, wherein the emissivity value of the pit face is greater than the emissivity value of the flue face.

Abstract: In a residential furnace having a layered insulation material on the inner walls of the heat exchanger compartment, the inner aluminum foil layer has a plurality of holes formed therein in order to allow for the outer layer to absorb the sound within the heat exchanger compartment and thereby reduce the noise emanating from the furnace. Both the density and size of the holes are optimized to maximize the sound absorption performance over the particular frequency ranges that are characteristic of the furnace.

Abstract: A fixture (30) adapted to permit the heated exchange of a liner (14) from an operating vertical furnace (10). The fixture is adapted to secure to the base of the liner (14) to both unlock and lower the heated liner, such as a silicon carbide liner, at an controlled rate. The fixture is also adapted to elevate a new liner into the operating vertical furnace at a controlled rate to control the rate of heating of the liner as it is inserted into the operating vertical furnace. The fixture includes an inner ring (34), a low-friction Teflon® ring (36), and an outer ring (38) permitting the rotation of the inner ring within the outer ring. Advantageously, the low friction ring comprises a flanged portion and a vertical portion allowing rotation of the inner ring within the outer ring even when elevated at extreme temperatures exceeding 500° C.

Abstract: An insulation system for furnaces and kilns in which the number of splits between the insulation modules and the heat leaks produced at open sections caused by temperature changes are eliminated, for using in structures having: a frame including a first and a second lateral sides in relation with a transversal axis; one or more openings including a surrounding frame, constituting a flue, each opening having two lateral sides and two longitudinal sides in relation with said transversal and whit a longitudinal axis; and a structural base, located inside the frame and coupled thereof, having an internal side facing to the housing of the furnace and an external side facing to the exterior of the furnace, said insulation structure comprising a first and a second elongated insulation modules having an upwardly projecting housing which isolates a longitudinal side of the flue frame; and a third and a fourth elongated insulation modules, having a vertical section which isolates a lateral side of the flue frame.

Abstract: Refractory wall structure for a blast furnace, in particular for a metallurgical furnace, such as for example a blast furnace with a high process temperature during operation, which wall structure is subjected to a high thermal loading. The wall structure comprises a steel outer wall, a refractory lining consisting of one or more layers of a well heat-conducting material on the inside of the outer wall, and a cooler for cooling the refractory wall structure, whereby the wall structure also comprises a permanent, well heat-conducting metallic filling in a gap in the refractory wall structure, which filling has been molten inside the gap and then after solidifying forms a low heat resistance across the gap.

Abstract: A refractory lining in the transition section of a gasifier to the waste heat boiler with claws/brackets for supporting refractory shaped bricks. Each claw is suspended on hooks in a pipe branch and is protected from overheating by cooling tubes. The refractory lining is supported in the tube bundle by brackets, which are arranged one on top of another and are welded to webs tube-web-tube welding of the tube bundle. The lower bracket at the cooling tube bundle and the horizontal tube wall are protected against clogging with slag by a refractory mass with a drip nose. Expansion joints are provided between the shaped brick segments under the brackets, whereas ring-shaped fiberboard segments are inserted above the claw.

Abstract: An anchor for connecting refractory material to a wall or other support structure for a kiln or other vessel is disclosed. The anchor includes a first member having a section along its length that is selectively configured and has a selective cross-sectional shape. The anchor includes a second member having a complementary engaging section. The complementary engaging section has a cross-sectional shape and dimension complementary to the selected configuration of the length of the first section of the first member. The complementary engaging section of the second member further has a selective configuration along its length complementary to the shape and dimension of the selective cross-sectional shape of the first section of the first member such that the two members complementarily engage to enhance heat transfer, while at the same time permitting relative rocking and rotational movement of the members in use.

Abstract: A puller and method for crystal growth using the Czochralski technique in which a temperature profile and a history of thermal conditions of a growing crystal is controllable with ease and a good accuracy, which puller comprises a crucible containing raw material, heater for melting by heating the raw material and a heat insulating cylinder surrounding them, the heat insulating cylinder being cross-sectionally divided by an annular separation gap or gaps into parts and which method is applicable to growth of such a single crystal as of silicon, germanium, GaP, GaAs or InP in the puller. Methods for controlling a temperature profile and a history of thermal conditions of a growing crystal using the czochralski technique in the puller.

Abstract: An incinerator and a process for the incineration of animal carcasses. The inner combustion chamber of the incinerator is lined with a high temperature fibrous insulation material and a stainless steel liner thereby permitting the temperature of the liner to become very hot during incineration. The animal carcass is deposited directly onto the stainless steel liner. Heat is then applied to the chamber, and the liner becomes red hot and radiates heat onto the carcass from all sides of the chamber. The burners are controlled by temperature responsive control devices to maintain the combustion chamber within a desired temperature range. In another embodiment, a stainless steel wall is disposed within the interior of the incinerator housing to form a combustion chamber and an afterburner chamber alongside the combustion chamber. The afterburner chamber includes a separate burner located near the bottom of the incinerator for heating the air as it enters the afterburner chamber.

Abstract: Cooling device with panels for arc electric furnaces, which is used in an electric melting furnace in cooperation with the vertical sidewall placed above the lower shell (11) of the furnace, the furnace comprising in its lower part one lower shell (11) to contain a bath (12) of melting metal and an upper shell defined by a plurality of panels (16) comprising a plurality of cooling tubes (17), the lower shell (11) including at its outer part a metallic containing element (15), the inner refractory having an upper edge (19) located substantially at the level of the upper edge of the layer of slag (14) contained above the bath (12) of melting metal, each panel (16) including an outer layer (116) and at least an inner layer (22) of cooling tubes (17), the layers (116, 22) developing vertically along the vertical side wall of the furnace above the refractory edge of the lower shell (11) and being separated by an interspace (23).

Abstract: A refractory brick that has a rear portion with a geometrical concavity on one side and a corresponding convex projection on the other side, the concavity and projection being matched so that the concavity mates with the corresponding projection of a similar refractory brick when the two are disposed in side-by-side relationship. Extending perpendicular from the base portion is a generally rectangular projection such that when a plurality of bricks are disposed in a side-by-side array, they are locked together by the mating concavities and projections, and the generally rectangular projections extend inwardly to form a thicker lining to withstand the force of a tap stream of molten metal for a longer duration.

Abstract: An incinerator and a process for the incineration of animal carcasses. The inner combustion chamber of the incinerator is lined with a high temperature fibrous insulation material and a stainless steel liner thereby permitting the temperature of the liner to become very hot during incineration. The animal carcass is deposited directly onto the stainless steel liner. Heat is then applied to the chamber, and the liner becomes red hot and radiates heat onto the carcass from all sides of the chamber. The burners are controlled by temperature responsive control devices to maintain the combustion chamber within a desired temperature range. In another embodiment, a stainless steel wall is disposed within the interior of the incinerator housing to form a combustion chamber and an afterburner chamber alongside the combustion chamber. The afterburner chamber includes a separate burner located near the bottom of the incinerator for heating the air as it enters the afterburner chamber.

Abstract: A method and apparatus for controlling the operation of a plurality of burners of a cupola. The method includes the steps of separately supplying air and fuel to each burner of the cupola, measuring the flow rates of air and fuel supplied to each burner, controlling either the flow rate of air or flow rate of fuel supplied to each burner as a function of a desired heat energy output of the burners and controlling the other of the flow rate supplied to each burner as a function of the measured flow rate of air or fuel supplied to each burner and a preselected ratio of flow rate of air supplied to each burner and of flow rate of fuel supplied to each burner.

Abstract: An insulation structure such as a cover provides desirable heat insulation for a heated metal container such as a ladle. The insulation structure is assembled in a manner affording ease of subsequent repair in high-wear areas of ceramic fiber insulation. The ceramic fiber insulation is at least partly in bundled form and the bundles are generally positioned so that fiber blankets are oriented in different directions in the structure, yet the fiber is all in snug fit and achieves highly efficient insulation.

Abstract: A graphite block for an induction furnace in the form of a right prism formed from a plurality of plates associated along adjacent end faces parallel to the axis of the prism. Each plate includes a longitudinal recess opening into its top face adjacent a first end and a longitudinal recess opening into its bottom face adjacent an opposite end. Each end face is provided with a flexible graphite joint. The association of plates results from a partial interfitting of a top face longitudinal recess of one plate with a bottom face longitudinal recess of a second plate, the recesses being adapted to leave a void of polygonal section between the plates. This void is occupied by a graphite key of similar section divided over its length into two parts meeting along an oblique surface.

Abstract: A tuckstone assembly (14) for an industrial type furnace (10) fills a space between a wall of the furnace and a supporting member (19) that supports the furnace superstructure. The tuckstone assembly (14) has a support block (26) having a sloped upper surface (27) and a nose block (37) having a mating sloped lower surface (38). The longitudinal profile of the tuckstone is reduced for insertion in the space of the furnace wall by sliding the nose block forwardly, and the enlarged nose portion (42) is made to cover the support plate (19) by sliding the nose block (37) back to where the ends of the support block and the nose block substantially coincide.

Abstract: A device repairs worn depressed surfaces around a tap hole opening in a blast furnace plate. The device includes a preformed frusto-conical member made of a refractory material that is flexible and rapidly baked. A ferrule is formed of frangible material and encloses the refractory member therein. The ferrule is fastened to the nose of a tap hole gun which impacts against the depressed surface thereby causing destruction of the ferrule and allowing adhering deformation of the refractory material to fill the worn depressed surface of the plate--around the tap hole.

Abstract: A method for forming an insulation lining of abutting modules in a high temperature chamber. The method comprises forming a modular fiber blanket surrounded by a retaining means to maintain the module in a pleated configuration. A plurality of hanger means cooperate with a support portion and an elongated prong means. The prong means is inserted into the hanger means and through the pleated body to form a plurality of modules. A surface is provided on the support part for engaging the prongs of an adjacent module to stabilize the module and ensure that the modules are accurately located and maintained in operative position on the interior surface of the high temperature chamber.

Abstract: A kiln for the drying of lumber utilizing panels attached to the kiln structure. The attached panels form the interior surface and the exterior surface of the kiln. The panels have a cavity for the placement of insulating material. The insulating material is encapsulated in a liquid impervious container thus preventing condensates from infiltrating the insulating material. The isolation of the insulating material from the ambient moist air of the kiln maintains the insulating quality of the insulation normally lost due to exposure to moisture laden air and also aids in preventing the corrosive effect of moist insulation in contact with the metal surfaces.

Abstract: A casing for a kiln includes at least one casing unit comprising: vertical and horizontal frame members assembled according to the shape of a framework of the kiln; outer plates secured to at least one of the vertical and horziontal frame members for covering the spacings encircled by said vertical and horizontal frame members; guide fittings provided at the spacings between outer plates adjacent in a longitudinal direction of the kiln for slidably supporting the ends of said outer plates; and securing means for securing said outer plates to said vertical frame member or horizontal frame member so that the spacings between the adjacent outer plates are expandable in a longitudinal direction of the kiln.

Abstract: An anchor system including a C-track and a two-pronged anchor capable of installing and holding sheet insulation material on a support surface in a compressed state is described. The method of installation utilizing the anchor system of the present invention provides for both the attachment of the insulation to the support surface and compression of the insulation during a single installation operation. The method involves forming a plurality of folds with the sheet insulation to a desired height followed by the insertion of one prong of the two-pronged anchor through the folds to compress the folds and hold the folds in position. The second prong of the anchor initially serves to aid in the compression of the folds and secondarily serves to connect the compressed insulation to a next layer of folds formed and stacked on top of the already formed folds. The use of a separate attachment means with each fold of the insulation material is not required.

Abstract: An insulation lining is formed of abutting modules. Each module includes a fiber blanket surrounded by a combustible sheet of material which compresses the fibers and holds the blanket in folded position. A hanger has spaced prongs extending from a support part which is disposed at one side of the module. The prongs pass through the blanket and extend beyond the opposite side of the module. A surface is provided on the support part for directly engaging the prongs of an adjacent module to stabilize adjacent modules and ensure that they are accurately located and maintained in operative position.

Abstract: A shaft furnace with a steel outer shell and a refractory lining inside the shell, has a sealed tap hole structure comprising a steel sleeve fitted to the outer shell, a permanent lining inside the sleeve and a refractory sealing material within said permanent lining. To improve the gas-tightness of the tap hole structure, a metal closure plate having an opening at which the tap hole is to be formed, is located within the steel sleeve and has its periphery coupled gas-tightly to the sleeve. A metal closure sleeve is coupled gas-tightly to said closure plate around said opening thereof and extends outwardly from said closure plate. Means e.g. conductive bricks are provided for removing heat from the closure plate and the closure sleeve.

Abstract: A melting furnace has a supporting structure of thermostable steel, and an internal shell of common steel, serving as a contact area for the refractory lining of the furnace.

Abstract: To open a furnace taphole that is closed by a body of plugging material and a tapping rod the tapping rod is driven into the interior of the furnace. Because the tapping rod is driven in and not withdrawn, it is not necessary to provide a second hammer striking blows in the opposite direction, but the hammer used to drive the tapping rod into the body of plugging material is again employed.

Abstract: An apparatus for securing loose wall brick or refractory lining in process heaters eliminates the need for the assistance of personnel outside the heater. Also, the requirement for scaffolding outside the heater is eliminated. Brick or refractory lining on process heater walls becomes loose and pulls away from the skin because of expansion and contraction over a period of time. The holdback plate assembly may comprise a rod of stainless steel which is threaded at one end (access end) and slotted at the other end (non-access end). A piece of flat bar is pivotally attached off center in the slotted end of the rod thereby allowing it to rotate freely for 90.degree. when unrestrained. The rod is inserted through a hole drilled through the brick and heater wall then positioned such that the flat bar rotates 90.degree. in the slot.

Abstract: A refractory furnace (10) is constructed to facilitate repair of worn or damaged refractory portions while the furnace is maintained at near-operating temperature. A sidewall (40) of the refractory furnace is comprised of a plurality of modular sections (85) each of which includes a refractory lining (87). One or more modular sections may be selectively replaced when becoming worn or damaged. Replacement is accomplished by external access and removal of the worn or damaged modular sections.

Abstract: A pyrolytic boron nitride crucible is provided. The crucible contains at least five wall layers consisting of first and second wall layers. The thickness of each of the first wall layers is 5 to 100 microns and the thickness of each of the second wall layers is 1/50 to 1/1 of that of the first wall layer. The total thickness of the entire wall layers is 0.5 to 3 mm. The first wall layer is bonded to and laminated alternately with the second wall layer.

Abstract: A lining for use in an aluminum reverberatory furnace or the like for heating molten aluminum in a cavity which cavity is formed by a roof, sidewalls and a bottom which are to be lined with refractory materials. The lining comprises a band of hot face refractory material around the interior periphery of the cavity sidewalls for contacting molten aluminum in the furnace at the normal operating levels of the upper surface of the molten aluminum. A layer of backup refractory material is interposed between the furnace shell and the band of hot face refractory material.

Abstract: A thermal insulation liner is provided for a chromatograph oven. The liner is moulded as a single bucket-shaped component 1 from ceramic fibers, typically alumino-silicate, bound together with an inorganic binder. The heat capacity and thermal conductivity of this material are both very low. The inner layer of the oven can be rapidly cooled for fast throughput of analyses and there is low risk of hand burns when changing chromatograph columns. The inner surface is mouled as a smooth shape, assisting the flow of circulated air and thereby reducing hot spots. Thermal insulation for the injector and detector of the chromatograph are also mouled in together with entry holes and mounting points 3,4, 5,6 to enable an inexpensive, easily assembled oven and chromatograph to be produced.

Abstract: The present device comprises an enclosing structure for a vacuum furnace hot zone. The enclosing structure, in a preferred embodiment, includes an outside wall (usually fabricated from stainless steel), and inside wall (usually fabricated from laminated graphite sheets) and layers of graphite felt located between the outside wall and the inside wall. The graphite felt is "cut back" so as to be shorter than both the outside wall and the inside wall, thereby creating a channel around the end of the enclosing structure. The present device further includes insert structure inserted into the channel and the insert structure comprises a backing of heat insulating rigidized material as well as a bonded front strip, in a preferred embodiment, fabricated from laminated graphite sheets. The insert seals and prevents any particles, emanating from the layers of loose fibered blanket of insulating material, from entering the hot zone, or other sections of the furnace, to contaminate the same.

Abstract: The present invention relates to a ceramic composite material having a high thermal conductivity. The ceramic composite material consists of a network of metal fibers embedded in a ceramic material and where the network of fibers on one side of the ceramic composite material extends out to the surface of ceramic composite material. A part of the metal fibers may be substituted by ceramic fibers and/or carbon fibers. Preferably, the area of the network of metal fibers occupies 60-95% of the total area of the surface wherein the network of metal fibers extends out to the surface of the ceramic composite material. The present invention further relates to a refractory lining for metallurgical smelting furnace wherein at least a part of the above described ceramic composite material is connected by a metallic bond to a cooled metallic part of the smelting furnace.

Abstract: A refractory product is shown in the form of a dense sintered alumina-chromia, zirconia-alumina-silica, zirconia-alumina body, or zirconia-chromia-alumina having less than about 8% of homogeneously distributed closed porosity formed by sintering an intimate interdispersion of fine particles of alumina-chromia, zirconia-alumina-silica, zirconia-alumina, or zirconia-chromia-alumina.

Abstract: A fluidizing gravity conveyor for hot particulate material which includes a heat resistant plate having a plurality of holes for receiving bubble caps or nozzles to disperse air flow from a lower plenum chamber to the upper material chamber. The upper material chamber is suitably lined with heat resistant material. Provisions are made for differential thermal expansion.

Abstract: A process for reducing the cracking tendency and improving the strength of specified rammed plastic refractory reactor liners is described, the process comprising heating reactor liner mounted in a reactor, prior to its first use, to a temperature of from about 490.degree. C. to about 510.degree. C., the heating being carried out by heating said liner at a rate to produce a temperature increase of the liner not greater than about 6.degree. C. per hour. A reactor comprising a vessel or tube having a liner of the type specified and cured in the manner described is also disclosed.

Abstract: A liquid fuel fired apparatus and method for the efficient distribution and utilization of heat in the melting of a particulate feedstock. The feedstock is preheated to an incipient softening point temperature in a vertically disposed shaft. The column of feedstock in the shaft is supported on the top of a freestanding pile of feedstock disposed on the floor of a surrounding melting chamber having downwardly diverging sidewalls. Liquid fuel burners direct hot combustion products towards and around the base and intermediate portions of the feedstock pile causing the outside of the pile to be melted. Gas at a temperature below the softening point temperature of the feedstock is introduced around the top of the pile to prevent the hot gases in the lower portion of the melting chamber from prematurely melting the feedstock.

Abstract: In a pasta dryer (1) with an insulation cladding encasing the dryer, the side parts of which cladding consist of individual convex wall elements (10) which can be braced in their edge regions against frame parts (13) of the dryer, the wall elements (10) are of convex design in the shape of a cylinder section and the associated frame parts (13) are adapted correspondingly.

Abstract: The present invention relates to a ceramic composite material having a high thermal conductivity. The ceramic composite material consists of a network of metal fibers embedded in a ceramic material and where the network of fibers on one side of the ceramic composite material extends out to the surface of ceramic composite material. A part of the metal fibers may be subtituted by ceramic fibers and/or carbon fibers.Preferably, the area of the network of metal fibers occupies 60-95% of the total area of the surface wherein the network of metal fibers extends out to the surface of the ceramic composite material.The present invention further relates to a refractory lining for metallurgical smelting furnace wherein at least a part of the above described ceramic composite material is connected by a metallic bond to a cooled metallic part of the smelting furnace.

Abstract: An oven wall straightener and a method for straightening an oven wall are disclosed. An angled beam (30) is mounted in such a way that rapid heat transfer from the oven wall (10) to the vertex (35) of the angled beam (30) causes the angled beam (30) to bow away from the oven wall (10). Beam straps (50) then pull the oven wall (10) toward the angled beam (30) restoring the oven wall (10) to a relatively straightened position.

Abstract: A vessel for holding high temperature bulk materials, such as a ladle for handling molten metal, includes a steel bucket containing a permanent outer layer of refractory material. Within the outer layer is an expendable layer which is made up from relatively rigid boards of compacted microporous thermal insulation material. Within the layer of microporous thermal insulation material is a further expendable layer of refractory material which covers the inner surface of the layer of microporous thermal insulation material. The thermal capacity of the expendable layer of refractory material is preferably less than the thermal capacity of the permanent outer layer of refractory material.

Abstract: A method and apparatus for heating molten steel in a steel making operation is disclosed, and which includes a refractory lined vessel having an open top, a removable cover adapted to overlie the top, and at least one plasma arc torch mounted so as to extend through the cover at an angle of about 60.degree.. The arc gas for the torch includes a substantial percentage of nitrogen, which permits a higher power level as compared to conventionally used argon, and the mass flow rate of the arc gas is maintained at a sufficiently high level to produce a continuous blast of gas which impinges at an angle upon any slag formed on the surface of the molten steel with sufficient force to move the slag and expose the underlying molten steel. As a result, the attachment of the arc to the underlying molten steel is facilitated, and the impingement of the gas contributes to the mixing of the steel to avoid heat stratification.

Abstract: An insulated refractory shield is provided to reduce heat loss through the exterior surface of the refractory shield while at the same time a cooling fluid is directed over the cast metallic refractory supports and hanger means through apertures in the hanger tube. Modular insulation units are provided and are retained between the exterior face of the refractory bricks and the hanger tube by means of specialized wedges and support clips.

Abstract: A tool for firing ceramics such as a setter and crucible comprises a ceramic foam body which has a three-dimensionally reticulated structure comprising plural interconnected ceramic strands, and a ceramic setting layer formed on at least one part of the surface of the ceramic foam body.