JP2012055948A - Gas blowing refractory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas blowing refractory capable of repeatedly using a body member, and suppressing a cost required for replacement low.SOLUTION: A fixed plate 2 is a gas blowing refractory, which is mounted on a container to blow gas to molten metal in the container. The fixed plate 2 includes a refractory body member 22, a gas blowing member 23 which is attachably/detachably fitted to the body member 22 to blow gas to molten metal, and a pipe 24 which is provided to the body member 22 to introduce gas in the gas blowing member 23.

Description

  The present invention relates to a gas-blown refractory, and particularly to a gas-blown refractory that is provided in a molten metal container and blows gas into the molten metal.

  A sliding nozzle device for opening and closing the nozzle is provided at the bottom of a molten steel container such as a ladle or a tundish in the steel making process. The sliding nozzle device is provided with a fixed plate having a gas blowing function in order to prevent solidification of the molten steel in the nozzle. FIG. 5 is a cross-sectional explanatory view of the sliding nozzle device disclosed in Patent Document 1. As shown in FIG. As shown in FIG. 5, the sliding nozzle device 95 is provided in an opening 90 a formed at the bottom of the ladle 90, and includes an upper nozzle 91, a fixed plate 92, a movable plate 93, and a lower nozzle 94. ing. Nozzle holes 91a and 92a are formed in the upper nozzle 91 and the fixed plate 92, and porous portions 91b and 92b in which a large number of communicating bubbles are formed are provided on the inner peripheral surfaces thereof. The movable plate 93 and the lower nozzle 94 are also formed with nozzle holes 93a, 94a, which can slide integrally with respect to the fixed plate 92 between an open position and a closed position. Is attached to the lower edge of the opening 90a. A porous portion 93b in which a large number of communicating bubbles are formed is formed in a portion of the movable plate 93 in the closed position located in the nozzle hole 92a of the fixed plate 92.

  An inert gas is introduced from the outside into the porous portions 91b, 92b, 93b of the upper nozzle 91, the fixed plate 92, and the movable plate 93, and flows through the nozzle holes 91a, 92a, 93a through the porous portions 91b, 92b, 93b. An inert gas is blown into the molten steel to prevent solidification of the molten steel.

JP 2004-223575 A

  However, since molten steel flows through the nozzle holes 91a, 92a, 93a, 94a of the sliding nozzle device 95 provided at the bottom of the molten metal container, the porous portions 91b, 92b, 93b surrounding these are exposed to high temperatures. It is. Among these, the porous portion 92b of the fixing plate 92 is a portion that always touches the molten steel when the molten steel is stored, and is clogged easily because the diameter is narrow. For this reason, the fixed plate 92 is usually discarded after being used a few times. Although the porous portion 92b is a part of the fixed plate 92, the entire fixed plate 92 is discarded due to the damage of only the porous portion 92b, which leads to an increase in cost required for replacement of the fixed plate.

  This invention is made | formed in view of this situation, and makes it a subject to provide the gas blowing refractory which can hold down the cost which replacement | exchange requires.

(1) The present invention is a gas-blown refractory that is attached to a container and blows gas into the molten metal in the container.
A fire-resistant main body member; a gas blowing member that is attached to the main body member and blows gas into the molten metal; and a gas passage that is provided on the main body member and introduces the gas into the gas blowing member. ,
The gas blowing member is detachably attached to the main body member.

  According to the said structure, a gas blowing member can be removed from a main body member. The gas blowing member is a portion that blows gas into the molten metal, and is easily exposed to high temperatures and damaged. For this reason, when a gas blowing member is damaged, a damaged gas blowing member can be removed from a main body member, and a new gas blowing member can be attached to the existing main body member. Therefore, the main body member with little damage can be used repeatedly any number of times, and the cost required for replacing the gas blowing member can be kept low.

  (2) It is preferable that a filling member made of mortar is interposed between the gas blowing member and the main body member. In this case, the gas blowing member can be separated from the main body member by breaking the filling member made of mortar, and the gas blowing member can be easily detached from the main body member. Because mortar is relatively soft, it can be easily broken by using a drill or the like.

  (3) It is preferable that the gas-blown refractory further has a nozzle hole through which the molten metal circulates, and the nozzle hole is constituted by a through-hole formed in the gas-blowing member. The nozzle hole is a portion through which the molten metal flows, but is a portion where the molten metal is likely to solidify and close when the molten metal flow is stopped by a shutoff valve or the like. The molten metal tends to adhere to the inner peripheral surface of the through hole of the gas blowing member constituting the nozzle hole, and it is necessary to frequently replace the gas blowing member. In the said structure, since a gas blowing member can be removed and replaced | exchanged from a main body member, the cost required for replacement | exchange of a gas blowing member can be restrained low.

  According to the gas blown refractory of the present invention, since the gas blowing member can be removed from the main body member, the main body member can be used repeatedly, and the cost required for replacement can be kept low.

It is sectional drawing of the sliding nozzle apparatus provided with the stationary plate as a gas blowing refractory material concerning Example 1 of this invention. It is the top view (a) of the fixing plate of Example 1, and AA arrow sectional drawing (b) of Fig.2 (a). FIG. 3 is a cross-sectional view around a nozzle hole of the fixing plate of Example 1. 3 is a cross-sectional view of the vicinity of an outer joint of the fixing plate of Example 1. FIG. It is sectional drawing of the sliding nozzle apparatus in a prior art example.

  Gas-blown refractories are attached to a container and inject gas into the molten metal in the container. The gas-blown refractory is a gas that has a refractory main body member and a communication hole that is detachably attached to the main body member and blows gas into the molten metal. It has a blowing member and a gas flow path that is provided in the main body member and introduces gas into the gas blowing member.

  The said container is a container which accommodates a molten metal, for example, a ladle, a tundish, etc.

  Examples of the molten metal include molten steel, molten iron, molten copper, and molten aluminum.

  The gas blown into the molten metal is, for example, an inert gas such as argon gas or nitrogen gas.

  The gas-blown refractory is an instrument that blows gas onto the molten metal in the container, and includes, for example, a fixed plate, a movable plate, and an upper nozzle that constitute a sliding nozzle device.

  The main body member is composed of a dense material excellent in fire resistance, such as alumina, alumina-carbon, magnesia-carbon, alumina-magnesia-carbon, alumina-spinel, carbon, alumina-zirconia. -It is better to use refractory bricks such as carbon.

  The said gas blowing member is provided in the part which blows gas into the molten metal of a gas blowing refractory. As the gas blowing member, for example, a dense body in which a through-hole for ventilation through which gas can circulate or a porous body having a large number of communicating bubbles can be used. The ventilation through hole is formed by, for example, burned-out material or laser drilling. The porous body having the communication bubbles is made of alumina, for example. The gas blowing member is connected to a gas flow path formed in the main body member, and the gas introduced through the gas flow path passes through the gas blowing member and is blown out to the molten metal.

  The gas blowing member is detachably attached to the main body member. For example, a filling member for detachably attaching the gas blowing member from the main body member may be provided between the gas blowing member and the main body member. Alternatively, the gas blowing member may be unevenly fitted to the main body member.

  The filling member is made of mortar. The mortar is a joint material for bonding the gas blowing member and the main body member. Mortar is generally low in rigidity and can be broken relatively easily with a drill or the like. The mortar should be fire resistant. The composition of the refractory mortar is preferably, for example, alumina or siliceous.

  The filling member made of mortar may be interposed over the entire boundary portion between the gas blowing member and the main body member, or may be interposed in a part of the boundary portion. The width of the filling member interposed between the gas blowing member and the main body member is good enough to allow insertion of a tool such as a drill tip, and is preferably 1 mm to 20 mm, for example. If it is less than 1 mm, the workability of separating the gas blowing member and the body member by the tool may be reduced. When it exceeds 20 mm, the volume occupied by the filling member composed of mortar in the gas-blown refractory is too large, and the rigidity of the entire gas-blown refractory may be reduced. The width of the filling member made of mortar is preferably 1 mm to 5 mm. This is because the workability of separating the gas blowing members is good while maintaining the high rigidity of the entire gas blowing refractory.

  The gas flow path formed in the main body member is, for example, a pipe embedded in the main body member. The pipe is inserted through a piping hole formed in the main body member. One end of the pipe is connected to a joint and communicates with the gas blowing member. The other end of the pipe is connected to a joint for external connection fixed to the outer surface of the main body member, or protrudes from the main body member. The pipe is preferably held by the main body member so that the gas blowing member can be removed from the main body member together with the gas blowing member when the gas blowing member is removed from the main body member. In this case, the pipe can be detached from the main body member together with the gas blowing member.

  Alternatively, the pipe is preferably detachably connected to the gas blowing member so that when the gas blowing member is removed from the main body member, the pipe is separated from the gas blowing member and only the gas blowing member is detached from the main body member. In this case, only the gas blowing member that is easily damaged can be removed from the main body member.

Example 1
The gas-blown refractory according to the embodiment of the present invention is a fixed plate constituting a sliding nozzle device. As shown in FIG. 1, the sliding nozzle device 81 is provided at the bottom of the ladle 80. The sliding nozzle device 81 includes an upper nozzle 1, a fixed plate 2, a movable plate 3, and a lower nozzle 4. The upper nozzle 1 is fixed to the inner peripheral surface of the opening 80b formed in the bottom 80a of the ladle 80, the fixed plate 2 and the movable plate 3 are attached to the lower end of the opening 80b, The lower nozzle 4 is fixed.

  The upper nozzle 1 and the fixed plate 2 are respectively formed with nozzle holes 11 and 21 whose axial centers coincide with each other. The movable plate 3 and the lower nozzle 4 are respectively formed with nozzle holes 31 and 41 whose axial centers coincide with each other. When the movable plate 3 and the lower nozzle 4 are integrated and slide between the closed position and the open position with respect to the fixed plate 2, the nozzle holes 11 and 21 of the upper nozzle 1 and the fixed plate 2 are movable. The nozzle hole 31 of the plate 3 is communicated with or blocked.

  As shown in FIG. 2, the fixing plate 2 includes a fireproof main body member 22, a through hole 22 a formed in the main body member 22, a gas blowing member 23 fixed to the inner wall of the through hole 22 a, and the main body member 22. And a filling member 25 that removably attaches the gas blowing member 23 to the main body member 22.

  The main body member 22 has a plate shape, and the planar shape is a horizontally long polygonal body. The outer peripheral portion of the main body member 22 is covered with a strip-shaped iron skin 22b, and the upper surface of the main body member 22 is covered with a flat iron plate 22c. On the paper surface of FIG. 2A, a through hole 22a is formed at the center of the main body member 22 in the vertical direction and on the left side of the central portion in the horizontal direction. As shown in FIG. 2B, the through hole 22 a penetrates in the thickness direction of the main body member 22. A step portion 22d having a stepped diameter is formed in the upstream portion of the through hole 22a. The step portion 22 d is provided with a gas blowing member 23 and a filling member 25 that joins the gas blowing member 23 to the main body member 22.

As shown in FIG. 3, the gas blowing member 23 is made of a dense body such as alumina, alumina-carbon, alumina, zirconia, or carbon, and has a cylindrical shape with a through hole 23a. The through hole 23 a of the gas blowing member 23 has the same axis as that of the through hole 22 a of the main body 22, and these inner peripheral surfaces are flush with each other and constitute the inner peripheral surface of the nozzle hole 21. The upstream end of the gas blowing member 23 forms the same plane as the peripheral edge of the through hole 22a of the main body member 22, and the downstream end of the gas blowing member 23 is formed by the filling member 25 at the step 22d of the through hole 22a. Easy to remove and fixed. The inner peripheral surface of the cylindrical gas blowing member 23 is a surface in contact with the molten steel, and the outer peripheral surface is covered with an iron plate 23b. In the downstream portion of the outer peripheral surface of the gas blowing member 23, a ring-shaped groove 23c communicating in the circumferential direction, and a radial ventilation through hole 23d having one end communicating with the ring-shaped groove 23c and the other end opened on the inner peripheral surface. And are formed. The ventilation through hole 23d is drilled by a laser. The axial width of the ring-shaped groove 23c is 0.5 to 5 mm, and the radial width is 5 to 30 mm. The diameter of the vent hole 23d is 0.2 to 2 mm. In this example, the gas blowing member 23 is formed of a dense body, and the ventilation through holes 23d are formed radially toward the inner peripheral surface by a laser or the like, but the ventilation through holes 23d are formed. Alternatively, the gas blowing member 23 itself may be formed of a porous body.
A small hole 23e communicating with the ring-shaped groove 23c is opened in a part of the iron plate 23b covering the outer peripheral surface of the gas blowing member 23, and the small hole 23e projects toward the radially outer side of the iron plate 23b. The provided inner joint 23f is connected. The inner joint 23f has a cylindrical shape, and the outer peripheral surface on one end thereof is screwed to the inner peripheral surface of the small hole 23e, and is further welded to the peripheral edge of the small hole 23e at a plurality of locations P along the circumferential direction.

  Further, on the paper surface of FIG. 3, a pipe hole 22g penetrates from the left end face toward the step 22d of the through hole 22a at the center position in the vertical direction of the main body member 22. A heat-resistant steel or copper pipe 24 is embedded in the piping hole 22g. One end of the pipe 24 is located on the filling member 25. One end of the pipe 24 is fitted into and screwed into an inner joint 23f having a tip end face on the filling member 25.

  As shown in FIG. 4, a small hole 22h is formed in the frame-shaped iron skin 22b surrounding the main body member 22, and the proximal end portion of the outer joint 22f is screwed to the inner peripheral surface of the small hole 22h. ing. The outer joint 22f is externally fitted and screwed to the other end of the pipe 24, and is further spot-welded at a plurality of locations P along the circumferential direction of the small hole 22h. An outer joint 22f connects the pipe 24 to an external pipe 26 that leads to a gas source of argon gas.

  As shown in FIG. 3, a filling member 25 is interposed in a portion where the main body member 22 and the gas blowing member 23 face each other. That is, the entire circumferential direction between the inner peripheral surface of the step portion 22 d of the through hole 22 a of the main body member 22 and the outer peripheral surface of the gas blowing member 23, and the lower end surface of the step portion 22 d and the lower end surface of the gas blowing member 23. A filling member 25 made of mortar is filled in between. The thickness T of the filling member 25 between the inner peripheral surface of the step 22d and the outer peripheral surface of the gas blowing member 23 is 5 to 20 mm, and the inner joint 23f protruding from the gas blowing member 23 is embedded in the filling member 25. Has been. The mortar is made of refractory alumina or siliceous.

  When the movable plate 3 slides between the open position and the closed position with respect to the lower end surface of the fixed plate 2, the nozzle hole 21 of the fixed plate 2 is opened and closed. When the movable plate 3 is in the open position, the molten steel in the ladle 80 flows down through the nozzle holes 11, 21, 31, 41 formed in the sliding nozzle device 81, and is temporarily stored in the tundish installed therebelow. The The outflow amount of the molten steel is adjusted by changing the opening area of the nozzle hole 21 of the fixed plate 2 by sliding the movable plate 3. Thereafter, the molten steel discharged from the tundish is discharged into a forming die and continuous casting is performed.

  On the other hand, when the movable plate 3 moves to the closed position, the lower end surface of the nozzle hole 21 of the fixed plate 2 is closed by the upper end surface of the movable plate 3, and the flow of molten steel is stopped.

When the molten steel in the ladle 80 becomes empty, the nozzle holes 11 and 21 of the upper nozzle 1 and the fixed plate 2 are filled with sand, and the nozzle holes 11 and 21 are prevented from being clogged at the next molten steel injection. After several times of charging, the gas blowing member 23 is damaged or clogged, and before reaching the usable limit number of use, the filling member 25 of the fixing plate 2 is broken with a drill or the like to The blowing member 23 is separated from the main body member 22.
The other end of the pipe 24 embedded in the main body member 22 is loosened from the outer joint 22f, and the other end of the pipe 24 is extracted from the outer joint 22f to the main body member 22 side. The gas blowing member 23 is removed from the main body member 22 together with the pipe 24 while maintaining the connection between the pipe 24 and the gas blowing member 23 at the inner joint 23f. Alternatively, after removing the pipe 24 from the inner joint 23 f and disconnecting the pipe 24 from the gas blowing member 23, the gas blowing member 23 is removed from the main body member 22. Thereafter, the pipe 24 is extracted from the main body member 22. Thereafter, a new gas blowing member 23 and a new pipe 24 are attached to the main body member 22.
When the pipe 24 is not damaged or is not damaged, only the gas blowing member 23 is removed from the main body member 22 without removing the pipe 24 from the main body member 22, and the new gas blowing member 23 is removed from the main body member 2. And a new gas blowing member 23 may be connected to one end of the existing pipe 24 by an inner joint 23f.

  In this example, the gas blowing member 23 is fixed to the main body member 22 by a filling member 25 made of mortar. The gas blowing member 23 is a part that blows gas into the molten metal, and is a part that is easily damaged by being exposed to a high temperature. The gas blowing member 23 is a portion where the molten steel stays when the movable plate 3 is in the closed position, and is a portion where the molten steel is easily solidified and clogged. For this reason, only the gas blowing member 23 can be removed and a new gas blowing member 23 can be attached to the main body member 22. Therefore, the main body member 22 with little damage can be used repeatedly any number of times, and the cost required for replacing the gas blowing member 23 can be kept low.

(Other)
In the first embodiment, the inner joint 23f that connects the gas blowing member 23 and the pipe 24 is welded to the periphery of the small hole 23e of the iron plate 23b, but the inner joint 23f may be screwed into the small hole 23e. In this case, the inner joint 23f can be removed from the small hole 23e by removing the screw connection with the small hole 23e, and the inner joint 23f can be separated from the gas blowing member 23.
In the first embodiment, the outer joint 22f is welded to the iron skin 22b. However, the outer joint 22f is fixed to the main body member 23 by being screwed into the small hole 22h of the iron skin 22b without being welded to the iron skin 22b. It may be. In this case, the outer joint 22f can be removed from the iron shell 22b, and the existing pipe 24 can be extracted from the small hole 22h formed in the iron shell 22b and replaced with a new one.

1: upper nozzle, 2: fixed plate (gas blown refractory), 3: movable plate, 4: lower nozzle, 11, 21, 31, 41: nozzle hole, 22: body member, 22a: through hole, 22b, 22c : Iron skin, 22d: Stepped portion, 23: Gas blowing member, 23a: Through hole, 23b: Iron plate, 23c: Ring hole, 23d: Through hole for ventilation, 24: Pipe, 25: Filling member, 26: External pipe, 80: ladle, 80b: opening, 81: sliding nozzle device.

Claims (3)

In the gas-blown refractory that is attached to the container and blows gas into the molten metal in the container,
A fire-resistant main body member; a gas blowing member that is attached to the main body member and blows gas into the molten metal; and a gas passage that is provided on the main body member and introduces the gas into the gas blowing member. ,
The gas blowing refractory, wherein the gas blowing member is detachably attached to the main body member.   The gas-blown refractory according to claim 1, wherein a filling member composed of mortar is interposed between the gas-blowing member and the main body member.   The gas blown refractory according to claim 1 or 2, wherein the gas blown refractory further has a nozzle hole through which the molten metal circulates, and the nozzle hole is configured by a through hole formed in the gas blown member. Refractory.

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