In this method for producing a refractory for a gas blowing nozzle, the refractory comprising a carbon-containing refractory having one or more gas-blowing fine metal pipes embedded therein, a series of steps for subjecting a carbon-containing refractory having fine metal pipes embedded therein to non-oxidative firing, and then performing an impregnation treatment in which the carbon-containing refractory is impregnated with an organic substance having a percentage residual carbon of 30 mass% or higher is performed multiple times. The non-oxidative firing and the organic-substance impregnation performed multiple times enhance the fracture energy of the carbon-containing refractory having fine metal pipes embedded therein, and extension of cracks caused by a steep temperature gradient around the working surface of the nozzle is inhibited when the gas-blowing nozzle is used. As a result, the life of the gas-blowing nozzle is greatly increased.
A flow channel has lateral cross-sectional shapes that are circular in a first section, and rectangular in a second section. The flow channel in the first section is continuously connected to the flow channel in the second section. The rectangular shape has a long/short side ratio of 3 or greater and 7 or less. The second section has a cross-sectional area S2, the first section has a cross-sectional area S1, and S2>S1. There are two first openings, which are open, in one-to-one correspondence, in two side faces of the second section. There are two second openings, one of which is open while extending from one side face of the two side faces to a bottom face of the second section, and the other of which is open while extending from another one side face of the two side faces to the bottom face of the second section.
Disclosed herein is a mud material comprising a refractory raw material, an organic binder, and a curing agent, wherein part or all of the organic binder is a novolac-type phenol resin, part or all of the curing agent is a methylene donor, and wherein the methylene donor is at least one selected from the group consisting of hexa(methoxymethyl)melamine and hexamethoxymethylolmelamine.
where Vi indicates a vertical opening dimension of each of the at least two outlet ports on the inner side, Hi indicates a horizontal opening dimension of each of the at least two outlet ports on the inner side, Vo indicates a vertical opening dimension of each of the at least two outlet ports on the outer side, and Ho indicates a horizontal opening dimension of each of the at least two outlet ports on the outer side.
211 of the flow passage 21 in the first portion 2, an opening part 5 includes two first openings 51 and two second openings 52, the first openings 51 open one each on the two side surfaces 44 of the second portion 4, one second opening 52A of the two second openings 52 opens across a bottom surface 45 of the second portion 4 and one side surface 44A of the two side surfaces 44, and the other second opening 52B of the two second openings 52 opens across the bottom surface 45 and the other side surface 44B of the two side surfaces 44.
Provided is a castable refractory that exhibits adequate strength after hardening and has excellent corrosion resistance to slag, and in which slag penetration and the adhesion of buildup are suppressed. The castable refractory contains: alumina including calcined alumina; hydrophilic graphite; spinel; and alumina cement. The content of the hydrophilic graphite is 1-10 mass%, the content of the spinel is 18-37 mass%, the content of the alumina cement is 5-11 mass%, the content of magnesia is 8 mass% or less, and the content of the calcined alumina is 10 mass% or less.
This mud material comprises a starting refractory material, an organic binder and a hardening agent, wherein: part or the whole of the organic binder is a novolac type phenolic resin; part or the whole of the hardening agent is a methylene donor; and the methylene donor is at least one selected from the group consisting of hexamethoxymethylmelamine and hexamethoxymethylolmelamine.
A sprayable fire-resistant composition according to the present invention includes primarily magnesia-spinel brick waste and magnesia feedstock as fire-resistant feedstock, wherein the magnesia-spinel brick waste content is 10 mass% or more relative to 100 mass% of the fire-resistant feedstock, and the magnesia feedstock content is from 0 mass%-90 mass% relative to 100 mass% of the fire-resistant feedstock.
A gas injection nozzle refractory with one or more gas injection small metal tubes buried therein has improved durability. The gas injection nozzle refractory includes a MgO—C central refractory with a small metal tube buried therein, and a MgO—C peripheral refractory surrounding the central refractory. The central refractory on a plane of the gas injection nozzle refractory has an external shape of a circle with a radius in the range of R+10 to R+150 mm concentric with a virtual circle with a minimum radius surrounding all buried small metal tubes, R mm being a radius of the virtual circle.
A submerged entry nozzle includes a bottomed cylinder having a vertical side face with at least two outlet ports and having an inner side and an outer side. The outlet port satisfies the following expressions: Vi / Vo ? 1.1Expression (1)Ho / Hi ? 1.1Expression (2)where Vi indicates a vertical opening dimension of each of the at least two outlet ports on the inner side, Hi indicates a horizontal opening dimension of each of the at least two outlet ports on the inner side, Vo indicates a vertical opening dimension of each of the at least two outlet ports on the outer side, and Ho indicates a horizontal opening dimension of each of the at least two outlet ports on the outer side.
This immersion nozzle 1 comprises at least two discharge holes 3 in a vertical side surface 21 of a bottomed cylindrical body 2, wherein the vertical opening width Vi and the horizontal opening width Hi of the discharge holes 3 on the inside of the bottomed cylindrical body 2, and the vertical opening width Vo and the horizontal opening width Ho of the discharge holes 3 on the outside of the bottomed cylindrical body 2 satisfy formula (1) and formula (2) below. Formula (1) … Vi/Vo ≥ 1.1 Formula (2) … Ho/Hi ≥ 1.1
The present invention improves the durability of a refractory for a gas blowing nozzle in which at least one thin metal tube is buried. This refractory for a gas blowing nozzle has a central refractory in which a thin metal tube is buried and an outer peripheral refractory which surrounds the outer periphery of the central refractory, wherein in a plane of the refractory for a gas blowing nozzle, when the radius of an imaginary circle having a minimum radius including all the buried thin metal tubes is R mm, the outer shape of the central refractory is concentric with the imaginary circle and is a circle having a radius of R+10 mm to R+150 mm, the central refractory is an MgO-C refractory in which a carbon content is 40-80 mass%, a metal Al content is 3-8 mass%, and a metal Si content is 0.30-1.0 times more than the metal Al content by mass ratio, and the outer peripheral refractory is an MgO-C refractory in which a carbon content is 10-25 mass%.
A method of producing an exothermic mold powder in a form of sprayed granules of the present invention includes spray-drying into granules, an aqueous slurry containing: a raw material blend; and a metal silicon powder and/or a silicon alloy powder, the method comprising adjusting the pH of the aqueous slurry to 13 or less.
A method for producing a spray-granulated exothermic mold powder, the method including a step for spray drying a starting material blend and a water-based slurry containing a metallic silicon powder and/or a silicon alloy powder to bring about granulation into granule form. The method for producing a spray-granulated exothermic mold powder according to the present invention is characterized in that the pH of the water-based slurry is adjusted to less than or equal to 13.
A method for producing a spray-granulated exothermic mold powder, the method including a step for spray drying a starting material blend and a water-based slurry containing a metallic silicon powder and/or a silicon alloy powder to bring about granulation into granule form. The method for producing a spray-granulated exothermic mold powder according to the present invention is characterized in that the pH of the water-based slurry is adjusted to less than or equal to 13.
The apparatus for continuous slab casting having a nozzle exchanging-holding mechanism capable of moving a submerged nozzle at the exchange of the nozzle through a moving-connecting space D of a base under a slide valve mechanism and keeping the connection between the submerged nozzle and the slide valve mechanism during the operation, and a rotation mechanism to rotate the base of the nozzle exchanging-holding mechanism, which is characterized by a fixing mechanism that fixes the submerged nozzle in the nozzle exchanging-holding mechanism by pressing the submerged nozzle toward one or both inner sides of the moving-connecting space D of the base in one or both directions perpendicular to the moving direction of the submerged nozzle during the nozzle exchange.
B22D 11/103 - Distributing the molten metal, e.g. using runners, floats, distributors
B22D 41/56 - Means for supporting, manipulating or changing a pouring-nozzle
B22D 37/00 - Controlling or regulating the pouring of molten metal from a casting melt-holding vessel
B22D 41/24 - Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings characterised by a rectilinearly movable plate
B22D 41/34 - Supporting, fixing or centering means therefor
B22D 41/40 - Means for pressing the plates together
B22D 11/04 - Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
A slab continuous casting apparatus according to this invention is configured to supply molten metal from a tundish to a slab water-cooled mold through at least an upper nozzle, a stopper, and an immersion nozzle and solidify the molten metal, and is provided with an immersion nozzle quick replacement mechanism. The slab continuous casting apparatus includes a discharge direction change mechanism that is provided between the stopper and the immersion nozzle and is capable of freely changing a discharge angle of the molten metal in a horizontal cross-section during casting.
The present invention assumes that an apparatus for continuous slab casting is provided with: a nozzle exchanging-holding mechanism in which an immersed nozzle is moved, during nozzle exchange, via a movement connection space D provided in a base under a slide valve mechanism, while the connection between the immersed nozzle and the slide valve mechanism is maintained during operation; and a turning mechanism that turns the base of the nozzle exchanging-holding mechanism. The present invention is characterized by comprising a fixation mechanism that fixes the immersed nozzle held by the nozzle exchanging-holding mechanism by pressing the immersed nozzle toward one or both inner sides of the movement connection space D of the base, in directions perpendicular to the movement direction of the immersed nozzle during nozzle exchange.
B22D 37/00 - Controlling or regulating the pouring of molten metal from a casting melt-holding vessel
B22D 41/24 - Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings characterised by a rectilinearly movable plate
B22D 41/34 - Supporting, fixing or centering means therefor
B22D 41/56 - Means for supporting, manipulating or changing a pouring-nozzle
The invention provides rotating a submerged nozzle during casting to arbitrarily change the discharge angle of molten metal, causing the molten metal in the mold for slab to be rotated and stirred. A slab continuous casting apparatus according to the invention supplies molten metal from a tundish to a water-cooled mold for slab through at least an upper nozzle, a slide valve and a submerged nozzle and solidified the molten metal and provided with a submerged-nozzle quick replacement mechanism. The slab continuous casting apparatus further includes a discharge-direction changing mechanism capable of arbitrarily changing discharge angle of the molten metal as viewed in a horizontal cross section, during casting, the discharge-direction changing mechanism being provided between a slide valve device for opening and closing the slide valve and the submerged nozzle.
This apparatus for continuous slab casting, in which molten metal (3) is supplied from a tundish (1) through at least an upper nozzle (4), a stopper (5) and an immersed nozzle (10) to a water-cooled slab casting mold (2) and solidified and which has a rapid immersed nozzle exchange mechanism, has a configuration in which a discharge direction-changing mechanism (30) that can change the discharge angle for the molten metal (3) in a horizontal cross-section at will during casting is provided between the stopper (5) and the immersed nozzle (10).
This apparatus for continuous slab casting, in which molten metal (3) is supplied from a tundish (1) through at least an upper nozzle (4), a stopper (5) and an immersed nozzle (10) to a water-cooled slab casting mold (2) and solidified and which has a rapid immersed nozzle exchange mechanism, has a configuration in which a discharge direction-changing mechanism (30) that can change the discharge angle for the molten metal (3) in a horizontal cross-section at will during casting is provided between the stopper (5) and the immersed nozzle (10).
The purpose of the present invention is to rotate a submerged nozzle during casting, freely change the discharge angle of molten metal, and turn and stir molten metal in a slab mold. The apparatus for slab continuous casting according to the present invention supplies molten metal (3) into a water-cooled slab mold (2) from a tundish (1) through at least an upper nozzle (4), a slide valve (5), and a submerged nozzle (10) and solidifies the molten metal, said apparatus for slab continuous casting having a submerged nozzle quick replacement mechanism attached thereto. The apparatus for slab continuous casting is configured such that a discharge direction change mechanism (20) that is capable of freely changing the discharge angle of the molten metal (3) in a horizontal cross section during casting is disposed between a slide valve device (8) for opening/closing the slide valve (5) and the submerged nozzle (10).
These non-aqueous injection refractories for repair contain a refractory aggregate and a binder, the non-aqueous injection refractories for repair being characterized in that the binder is a water-soluble liquid resol-type phenolic resin, and the compounded amount of polyhydric alcohol is within a range of 5-60 mass% when the total amount of water-soluble liquid resol-type phenolic resin containing polyhydric alcohol and polyhydric alcohol is taken as 100 mass%.
A slide valve apparatus for automatic application of surface pressure is configured to include a connection switching device (20) for switching a connection position of a drive device (7) and a slide case (4) between a first connection position (discharge position) during molten metal discharge and a second connection position (surface pressure operation position) during surface pressure application/release. As a result, the drive stroke of the drive device can be greatly reduced and the already installed drive device can be used as is when a SV apparatus is upgraded.
F16K 3/16 - Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing facesPackings therefor with special arrangements for separating the sealing faces or for pressing them together
A submerged nozzle for continuous casting of molten metal, wherein two or more discharge hole flow passages are provided on a cylindrical side surface of a submerged nozzle, and first and second inner surface side walls and first and second outer surface side walls of the discharge hole flow passages in a horizontal cross-section of the submerged nozzle when in use are composed by straight lines formed so as to be inflected at an inner side point of inflection and an outer side point of inflection.
A portion from the lower end position of a detection head (11) to the lower measurement limit of the detection head (11) is divided by pitches of a prescribed interval. For each of the height positions divided by the pitches of the prescribed interval, a plurality of virtual level plates (40) having a gap with the long side of a mold (1) of less than or equal to 2 mm are provided, and at each height position, the virtual level plate (40) corresponding to the height position is used for calibration.
G01F 23/26 - Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
G01F 25/00 - Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
31.
SLIDE VALVE DEVICE FOR AUTOMATIC SURFACE PRESSURE APPLICATION
The purpose of the present invention is to obtain a more compact slide valve device as a result of shortening the stroke of a drive device. This slide valve device for automatic surface pressure application has a configuration whereby: the drive stroke of the drive device can be greatly reduced in comparison to conventional slide valve devices; and the existing drive device can continue to be used when the slide valve device is updated, as a result of having a coupling switching means (20) for switching the coupling position of the drive device (7) and a slide case (4), between a first coupling position (discharge position) for molten metal discharge and a second coupling position (surface pressure operation position) for surface pressure application/release.
An object of the present invention is to improve the quality of a slab by stably generating a rotational flow in molten steel in a mold. A submerged nozzle for continuous molten metal casting according to the present invention has at least two discharge hole passages (2) on a cylindrical side surface of a submerged nozzle (3), and first and second inner surface side walls (6 and 7) and first and second outer surface side walls (10 and 11) of the discharge hole passages (2) on a horizontal cross section of the submerged nozzle (3) in use are constituted by a straight line formed by being inflected by an inner side inflection point (5) and an outer side inflection point (9). Therefore, the rotational flow in the molten steel can be stably generated in the mold by just improving the shape of the discharge hole passages of the submerged nozzle without having to add a change to other facilities, and the quality of the slab can be improved.
A molten surface gauge (20) provided with an oscillator (3), a feedback amplifier (4), and a detection head (5) having a primary coil (7) and a pair of secondary coils (8, 9) which are differentially connected to one another. Therein, the output of the feedback amplifier (4) is supplied to the primary coil (7), the output of the secondary coils (8, 9) is fed-back to the feedback amplifier (4), and the level of the molten surface within the mold is measured on the basis of the output of the feedback amplifier (4) which varies in accordance with changes in the level of the molten surface. The gauge is further provided with a bandpass filter (12) which extracts a standing wave signal mixed into the output of the feedback amplifier (4), and a differential amplifier (14) into which are input the extracted standing wave signal and the output signal of the feedback amplifier (4), said signal containing a standing wave signal. The standing wave signal included in the output signal and the extracted standing wave signal are counterbalanced by the differential amplifier (14), and thus the standing wave signal is removed.
The eddy current mold level sensor is provided with an oscillator (3) that sends an alternating current signal of a prescribed frequency, a feedback amplifier (4) to which the alternating current signal is supplied, and a detection head (5) having a primary coil (7) and a pair of secondary coils (8,9) that are mutually differentially connected. The output of the feedback amplifier (4) is supplied to the primary coil (7), the output of the secondary coils (8,9) is fed back to the feedback amplifier (4), and the molten steel surface level inside the mold is measured on the basis of the output of the feedback amplifier (4), which changes according to changes in the molten steel surface level. A magnetic shield (12) is provided on the upper end face or on the upper end face and side faces of the detection head (5).
The mold is divided at a pitch of a prescribed interval from the lower end position of a detection head (11) to the lower limit of measurement of the detection head (11), a plurality of virtual level plates (40) separated from the long side of the mold (1) by a gap of no more than 1 mm are provided at each of the height positions dividing the mold at the pitch of the prescribed interval, and calibration is realized using the virtual level plate (40) corresponding to each height position.
A curved surface weld overlay method comprises: a first step of tack welding either steel or stainless steel netting material (29-31) in weld regions which are formed in the outer side of a bent portion (16) in the radial direction at the inner part of an inner pipe (14) of a lance, which is formed in whole or in part from a curved surface; and a second step of carrying out an overlay weld with a metal having heat and abrasion resistance upon the netting material (29-31) and forming overlays (19-21) in the weld regions. It is thus possible to smoothly carry out on an inner-side surface of a steel structure having a curved surface (for example, a pipe having a bent portion) an overlay weld with a metal having heat and abrasion resistance.
In order to simplify work of applying and releasing a surface pressure in a slide valve device constructed of a fixed plate, a slide plate, a seal plate, and the like, provided is a slide valve device for automatic surface pressure application and a surface pressure application method therefor, the slide valve device including: a base frame (2) including a positioning member (51) for determining an arrangement location (X) of a seal case (21) and a stopper (52) for fixing the seal case (21) at the arrangement location (X); and a slide case (4) including a pusher (53) for sliding the seal case (21) together with the slide case (4) when sliding the slide case (4) in a surface pressure application direction.
A gas blowing nozzle which is not required to be increased in length, is not required to be exchanged, can be used in existing refining facilities without largely modifying the facilities, does not require the opening of a standby nozzle at the time of the changeover of a gas blowing operation, and has a further extended service life. A gas blowing nozzle comprises: a first nozzle section (10) provided with first metallic narrow pipes (11), a first surge tank (12), and a first fireproof substance (13), the first metallic narrow pipes (11) having furnace-side tips which are exposed to the inside of the furnace and being in a state in which the first metallic narrow pipes (11) can blow gas into molten metal within the furnace; and a second nozzle section (20) provided with second metallic narrow pipes (21), a second surge tank (22), and a second fireproof substance (23), the second metallic narrow pipes (21) being embedded in the fireproof substance and having closed furnace-side tips. When the damage and wear of the fireproof substance (23) progress and reach the furnace-side tip of the second metallic narrow pipes of the second nozzle section, the blowing of gas from the second metallic narrow pipes (21) of the second nozzle section (20) is started and the blowing of gas from the first nozzle section (10) is stopped.
Disclosed is a circulation tube refractory product which is a cylindrical structure of a single body and which prevents cracks, breakage, and damage from joints. The disclosed circulation tube refractory product for an RH furnace is used in a vessel (1) at the bottom of the RH furnace and comprises a cylindrical circulation tube refractory product (2). The aforementioned circulation tube refractory product (2) is configured as a cylindrical structure of a single body.
In order to simplify the application and release of surface pressure in a slide valve apparatus comprising a fixed plate, a slide plate, a seal plate, and the like, a slide valve apparatus for the automatic application of surface pressure is disclosed in which a base frame (2) is equipped with a positioning body (51) for determining the placement site (X) of a seal case (21) and a stopper (52) for fixing the aforementioned seal case (21) in the placement site (X), and in which a slide case (4) is equipped with a pusher (53) for concurrently sliding the aforementioned seal case (21) when the aforementioned slide case (4) is slid in the direction of surface pressure addition. Also disclosed is a surface pressure application method thereof.
A submerged nozzle supporting-replacing mechanism, which is constituted to set an entire width dimension (L3) of each of clampers (20 and 21) to be smaller than a flange diameter dimension (L1) of a submerged nozzle (9) so as to position each of the clampers (20 and 21) by a positioning member (26), and so as to guide an upper surface (43) of a fresh submerged nozzle (9A) by a positioning liner (6), to thereby regulate a height position of the fresh submerged nozzle (9A) during movement in a horizontal direction thereof. The position of the clampers are regulated by setting the entire width dimension of the clampers to be smaller than the flange diameter dimension of the submerged nozzle, which can be smoothly replaced by providing the positioning liner.
B22D 35/00 - Equipment for conveying molten metal into beds or moulds
B22D 37/00 - Controlling or regulating the pouring of molten metal from a casting melt-holding vessel
B22D 39/00 - Equipment for supplying molten metal in rations
B67D 7/00 - Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
Provided is an inversely inclined full-lining structure of lining bricks, which can prevent the bricks from cracking and dropping so that it can perform a stable operation. The inversely inclined full-lining structure comprises a furnace bottom (4), a lower corner portion (5), a bottom/lower-corner boundary (30), a straight drum portion (6), a constricted portion (7) and a furnace mouth (8) sequentially in the recited order from the bottom of a furnace (20). The individual lining bricks (5a, 6a and 7a) of the lower corner portion (5), the straight drum portion (6) and the constricted portion (7) are prevented from cracking and dropping by inclining the same fully inversely.
Provided is an immersion nozzle for continuous casting, in which the neck part of a cylindrical refractory object can be prevented from being damaged due to a pressing force or a stress by forming a metal case provided for the cylindrical refractory in a double structure configured from an outer part and an inner part. The immersion nozzle for continuous casting comprises an inner metal case (12) provided onto a part or the entire of the outer surface of the cylindrical refractory object (1), a tapered metal part (12a) so formed on the inner metal case (12) as to correspond to the tapered part (11a) of the cylindrical refractory object (1), and an outer metal case (13) provided outside of the inner metal case (12). At least parts of the metal cases (12, 13) are joined to each other.
This invention provides a 旜hot spray repairing material” which has excellent peeling resistance and can realize short-time curing. The hot spray repairing material comprises a refractory material containing 20 to 40% by weight of grains having a size of not more than 75 &mgr;m, and a binder for forming a carbon bond by hot processing. The hot spray repairing material is characterized in that 5 to 50% by weight, based on the total amount of the refractory material and the binder, of a metal powder or an iron alloy powder containing iron (Fe) as a main component and having a grain size distribution wherein not less than 70% by weight of the grains is accounted for by grains having a grain size of not more than 1.0 mm.
Disclosed is a dip nozzle supporting-replacing mechanism, which regulates the positions of individual clampers by making the individual full-width sizes of the clampers smaller than the flange diameter size of a dip nozzle and which smooths the replacement of a new dip nozzle by providing a positioning liner, so that the mechanism is simply constituted at a low cost. The dip nozzle supporting-replacing mechanism is constituted to make the individual full width sizes (L3) of individual clampers (20 and 21) smaller than the flange diameter size (L1) of a dip nozzle (9), to position the individual clampers (20 and 21) by a positioning member (26), and to guide the upper face (43) of a new dip nozzle (9A) by a positioning liner (6) thereby to regulate the height position of the new dip nozzle (9A) at a horizontally moving time.
Disclosed are a dipped nozzle supporting-replacing mechanism and a lower-nozzle/dipped-nozzle sealing method, for relaxing a bending stress to be applied to a lower nozzle, by joining the ring-shaped taper portion of the lower nozzle to the receiving taper portion of a receiving member, thereby to prevent the occurrence of a vertical cracking, and for improving the sealing properties of the lower nozzle and a dipped nozzle with a seal member. The dipped nozzle supporting-replacing mechanism and the lower-nozzle/dipped-nozzle sealing method are constituted to suppress the vertical cracking by joining the receiving taper portion (3A) of the receiving member (3) to the ring-shaped taper portion (4A) of the lower nozzle (4), when the upper face of the dipped nozzle (6) is joined by a clamper (5) to the lower face of the lower nozzle (4) supported by the receiving member (3) of the lower frame (2) of a slide valve device (1).
This invention provides a nonaqueous baking repairing material which, while enjoying simple execution, can substantially reduce the time required for baking after execution. This baking repairing material is characterized by comprising 5 to 30% by weight of a binder capable of forming a carbon bond upon hot working and less than 1 to 5% by weight of an iron powder with the balance consisting of a refractory aggregate.
A slide valve device for automatic surface pressure application having a three-layer structure, in which a seal case is slid by using a cam surface and a mobile body, in which force for surface pressure application is increased, and that has a compact shape. In the slide valve device having a three-layer structure, the mobile body of the seal case is adapted to be slidable on a supporting surface of a spring holder. The slide case and the seal case are connected together by connection means or a connection stopper. The cases are slid by an actuator to perform surface pressure application and release.
A refractory brick which has durability equal to that of alumina-magnesia casting materials and is suitable for use especially as a ladle for steelmaking. For producing the refractory brick, a raw alumina material and a raw magnesia material at least 90 mass% of which is accounted for by fine particles of 0.5 mm or smaller are used. The brick has a total content of Al2O3 and MgO of 90 mass% or higher, MgO content of 4-16 mass%, SiO2 content of 0.5-5 mass%, and total content of Na2O and K2O of 0.3-2 mass%, with the remainder being unavoidable impurities and Al2O3. It is obtained by press-molding a raw-material mixture and then heating the molding at 100-1,150°C.
A blockage material for molten metal tapping hole, characterized by consisting of a refractory aggregate and a binder, the binder being one of 1 to 3 Pa sec viscosity at 60°C composed of over 70 to 90 mass% of novolac phenolic resin of less than 400 number average molecular weight measured by gel permeation chromatography (referred to as GPC) and 10 to less than 30 mass% of solvent.
An object of the invention is to provide a casting nozzle in which attachment and deposition of alumina or the like can be prevented while a drift of molten steel can be prevented.
The casting nozzle according to the invention is characterized in that the casting nozzle has a molten steel flow hole portion in which “a plurality of independent protrusion portions and/or concave portions” are disposed so that each of the protrusion portions and/or concave portions has a size satisfying the expression (1): H≧2 mm and the expression (2): L>2×H mm [in which “H” shows the maximum height of the protrusion portion or the maximum depth of the concave portion, and “L” shows the maximum length of a base portion of the protrusion portion or concave portion].
B05B 1/00 - Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
B05B 1/34 - Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl
Non-metallic minerals for building or construction,
synthetic building materials, ceramic building materials,
bricks and refractory products, cement and its products,
building stone.
Non-metallic minerals for building or construction,
synthetic building materials, ceramic building materials,
bricks and refractory products, cement and its products,
building stone.
