JPH04507377A - Transparent MgO nozzle - Google Patents

Abstract

An immersion nozzle (10) for continuous metal casting having an elongated nozzle body (12) formed from a porous, gas permeable refractory material. The nozzle body has a conduit (18) extending longitudinally therethrough and an inner surface (20) which defines the conduit. The nozzle body also includes an outer surface defining a predetermined body profile and channels (24, 26, 28, 30) formed in the outer surface (16) of the nozzle body. A metallic housing (14) encases the nozzle body and has an inner surface (32) dimensioned to substantially conform to the profile of the nozzle body. The housing is secured to the nozzle body by a refractory mortar (40) which forms a rigid relatively air-tight layer between the housing and the nozzle body, wherein the channel means form internal passages in the nozzle. A port (34) is provided on the housing in registry with the channels in the nozzle body. The port is connectable to a source of inert gas, which is operable to force the gas into the passages and into the porous refractory material.

Description

[Detailed description of the invention] Transparent MgO nozzle Matasato Kodan The present invention relates to casting and steelmaking elements, particularly those used for pouring molten metal. This invention relates to an infiltration nozzle typically provided in pots and tundishes.

Matasato Evening view Ladles and tundishes for pouring molten metal have a molten metal container at the bottom. To convey the flow to a subsequent process, e.g. tundish, inner mold or continuous casting mold Requires single or multiple spouts. These spouts typically have a good Formed with a special nozzle made from refractory material with corrosion resistance. molten metal Control of casting speed is generally done by a Stosova loft device or a slide gate device. Both devices include similar refractory materials. A typical nozzle is is alumina-silica, chromium-alumina, alumina-graphite or silica Consists of conia-graphite refractory material. The problem with this type of material is that These materials have an affinity for impurities in steels, especially aluminum guild steels. It is to have. In this regard, deposits may be chemically and/or Alternatively, it may adhere mechanically and form deposits there. these deposits increases until the flow stops, restricting the flow and sometimes occluding the orifice. Ru.

In an attempt to solve the blockage problem caused by increased deposits, inert gas was introduced into the hole. It is known to use porous gas permeable nozzles for this purpose. conventionally known Transparent nozzles typically have a refractory material and a metal jacket spaced apart. or a housing, defining an air space or manifold therebetween. .

Gas is introduced into this space or manifold through metal jacket fittings. be done. The pressure builds up between the refractory material and the Jaquent, and finally the permeable refractory material sufficient pressure is reached to overcome the resistance inherent in the material, at which point the inert gas and flows into the nozzle hole. The introduction of inert gas creates a gas filament along the inner surface of the hole. Ideally, this would slow down the build-up of deposits. (Advantages of inert gas An additional benefit is that it creates a positive pressure that prevents the introduction of air into the molten metal. It is something that happens. ) However, these devices require a large amount of gas flow and deposits in the hole. cannot be delivered to specific areas where it is most likely to adhere. Furthermore, the nozzle By maintaining an inert gas film in the hole, retards the adhesion of deposits there This can increase the nozzle lifespan, but it is usually Completely eliminate chemical and/or mechanical affinities with impurities in metals Never. In this regard, the most common nozzles are based on alumina-silica. It has a strong affinity for impurities in steel.

Other materials, e.g. oxidizing materials known to have no affinity for alumina. Gnesium (MgO) is rarely tolerated in nozzle manufacturing or Rui is never used. Regarding magnesium oxide (MgO), its The unpopularity is due to the perceived possibility of cracking.

Anyway, between the impurities in molten steel and the materials found in normal nozzles. chemical compatibility and the physical shape of the nozzle orifice (areas that facilitate deposit build-up). area or shape) will limit the nozzle life.

The present invention overcomes the aforementioned and other problems and eliminates alumina and other impurities in molten metal. We offer molten steel pouring nozzles that have a substantially reduced affinity for This nozzle is porous, has a high degree of gas permeability, and Provide a large amount of gas flow to the area.

It's okay again! In accordance with a preferred embodiment of the invention, the An immersion nozzle for continuous casting is provided having a long nozzle body. The nozzle body is long It has a conduit extending therethrough and an interior surface defining the conduit. nozzle book The body also forms along the nozzle body, with an outer surface defining a predetermined body profile. and a channel device. A metal housing encloses the nozzle body. There is. The housing has an inner surface dimensioned to substantially match the profile of the nozzle body. has. Equipped with a device for fixing the housing to the nozzle body, this fixing device forming a tight, relatively airtight layer between the tip and the nozzle body; A channel device defines an internal passage within the nozzle. Port device in housing , provided in alignment with the channel arrangement of the nozzle body.

The boat device is capable of injecting gas into the passageway and into the porous refractory material. can be connected to an inert gas source.

In particular, the long nozzle body consists of several different particle sizes of magnesium oxide (MgO). Preferably formed from a mixture of particles, the nozzle body is a "micro-continuous porous" ”. Micro-continuous porosity is characterized by passages or passages between magnesium oxide (MgO) particles. The gap is relatively small, and the inert gas passing through the nozzle body can flow along the inner surface of the nozzle hole. By this we mean a condition that provides a uniform layer of microscopic gas bubbles. Microporosity also The small passages and gaps between magnesium oxide (MgO) particles are filled with an inert gas. It requires a large amount of back pressure to pass. This relatively low back pressure causes the nozzle hole to Maintain a uniform, relatively thick layer of inert gas along the inner surface of the molten metal and conduit surface. It is also believed that it helps prevent contact with people. The uniformity of this inert gas layers, no affinity for alumina deposition, and overall alloying in molten metal. The use of magnesium oxide (MgO), which is inert to agents and other impurities; provides an intrusion nozzle that is less likely to result in increased deposits along the inner surface of the nozzle do.

The present invention provides inert gas in the nozzle hole or conduit where impurity build-up is most severe. It is important to provide a device for transmitting the flow of water. In this regard, the environment A channel device consisting of shaped channels or grooves is formed on the outer surface of the nozzle body. Ru. Each channel is placed adjacent to the area in the nozzle hole where impurity build-up is most severe. areas of the hole that may be subject to increased deposits. It is preferable to provide it immediately adjacent to. In this configuration, the inert gas flow rate is Augmentation occurs through the nozzle wall adjacent to the channel. Therefore, the present invention The increased inert gas flow is channeled along the outer surface of the nozzle body. is directed to a specific location within the nozzle hole by selectively positioning the .

What is more important about the above embodiment of the present invention is that the fireproof nozzle body and the metal housing A space (i.e., a manifold) may be provided between the Unlike typical previously known permeable nozzles, the metal housing of the present invention It is directly fixed to the nozzle body. This direct installation has several advantages. Provide points. First, the housing acts as a barrier or seal, allowing the inert Prevents gas from escaping outward from the surface of the nozzle body and through the walls of the refractory nozzle It is to restrict the gas flow and direct it into the internal conduit. Second, the housing is Acts as a strong sleeve, holds the refractory nozzle body together, and protects the nozzle from penetrating it. It is also important to prevent thermal shock cracks from opening. Therefore, the present invention Magnesium oxide (MgO) with potential or recognized potential for Allows the use of materials such as Third, the housing directly against the refractory nozzle The arrangement provides increased backpressure requirements due to the microcontinuous porosity preferred in the present invention. This is to make things easier. Normal existing manifold (space) design form Known permeable nozzles have an inherently high hood that can destroy the manifold jacket. may be subject to stress.

One form of the invention provides a molten steel nozzle with improved operating life than previously known nozzles. An object of the present invention is to provide a nozzle for a ladle or tundish used for pouring.

Another form of the invention provides a nozzle as described above that is less susceptible to deposits on the inner surface of the nozzle. It is to offer cheats.

Another form of the invention is that the nozzle removes alumina, impurities or alloying in the molten steel. providing a nozzle as described above having a substantially reduced affinity for the agent; That is.

Yet another aspect of the invention provides that the nozzle is gas permeable and has a uniform, high degree of porosity. It is an object of the present invention to provide a nozzle as described above, having a high efficiency.

Yet another form of the invention provides that the passing inert gas stream is used to remove deposits from the nozzle bore. The purpose of the present invention is to provide a nozzle as described above, which is sent to an area where there is a high possibility of

Yet another form of the invention provides that the nozzle is made primarily of magnesium oxide (MgO). An object of the present invention is to provide a nozzle as described above.

Yet another aspect of the invention provides a method as described above in which cranking is less likely to occur. 6 Yet another aspect of the invention is to provide a nozzle for casting and steel making. Made of magnesium oxide (MgO) used for pouring molten steel An object of the present invention is to provide a method for forming a gas permeable element.

The foregoing and other forms and advantages will be apparent from the preferred embodiments of the invention with reference to the accompanying drawings. It will become clear from the following explanation.

Figure (7) ft” skin The present invention has a physical form in predetermined parts and arrangement configurations of parts, and embodiments thereof are clearly described. The details are described in the specification and illustrated in the accompanying drawings.

FIG. 1 is a partially cross-sectional perspective view of a transparent tundish nozzle showing one embodiment of the present invention. figure, Figure 2 is a sectional view taken along line 2-2 in Figure 1, and Figure 3 is a cross-sectional view taken along line 3-3 in Figure 2. Cross-sectional view.

It's new. The drawings illustrate preferred embodiments of the invention, but are not intended to limit it. For reference, FIG. 1 shows a nozzle I used in a tundish for pouring out molten metal. Indicates O. The nozzle 10 is generally a porous refractory surrounded by a housing 14. It consists of a core 12 of material. In the illustrated embodiment, core 12 has a generally cylindrical shape. , an outer surface 16 and an elongated hole or opening 1 extending longitudinally therethrough along its axis. 8. Hole or aperture 18 defines an interior surface 20 . It is clearly shown in Figure 2.3. As shown in FIG. A widening portion 22 is provided. Conical portion 22 prevents molten metal from passing through opening 18. Provided for ease of use.

The outer surface 16 of the core 12 has a plurality of holes extending around the periphery of the core 12 and spaced apart in the axial direction. An annular channel or groove 24, 26, 28 is provided. slightly larger vertical cha A channel 30 interconnects channels 24,26,28. channel 2 4.26.28 is located at the nozzle as will be understood from the detailed description of the invention below. This can be changed depending on the size, shape, and function of the module itself.

According to the invention, the core 12 consists of magnesium oxide (MgO) particles. but , by reading the specification, it will be understood that the present invention applies to other porous ceramic materials as well. It will be appreciated that advantageously applied and not limited to magnesium oxide (MgO) Will. A book made from magnesium oxide (MgO) produced from seawater. The chemical analysis results of the inventive nozzle are as follows: MgO 97.9% Ca　O0.8% 5iOz 1.2% A1□03 0.9% Fe, o, 0.5% The latter material is commonly found in naturally occurring magnesium oxide (MgO). It is an impurity. The magnesium oxide (MgO) particles forming the core 12 are naturally obtained from materials that occur in the world, by fusion, or from salt water.

The sizing of the particles or particles forming the core 12 is very critical and the nozzle provides good wear resistance while providing sufficient porosity to allow good gas flow. It is desirable to provide sufficient density to In other words, a minute series of It is desirable to form a nozzle with pores. Therefore, the nozzle core 12 is Composed of a combination of magnesium oxide (MgO) particles of different sizes be done. Has sufficiently fine pores and good wear resistance, yet gives good gas flow An example of a nozzle core that has sufficient porosity to: Nobuko soilッ■-leather-X Largest piece 0.125” + U, S, 40) Soshu 10% medium coarse piece U , 5.40 mesh + t1.5.50 mesh 20% coarse piece Ll, 5t50 Metush+I1. S, 65 mesh 30% fine pieces U, 3.65 mesh + σ , S, 100 mesh 20% medium fine pieces U, 5.100 mesh 10, 5.1 50 mesh 5% Finest piece U, 5.150 mesh 15% total 100% It is not intended that the invention be limited to the above particle sizes or percentages or It has been shown that satisfactory nozzles can be produced by varying the above particle size percentages. Of course, this can be understood.

Although no specific tests were conducted, magnesium oxide (M), which is satisfactory according to the present invention, g.O) For manufacturing the core, the following particle size ranges shall be acceptable: Believable: Grain King Ezu Composition % Range Quantity Large piece 0.125' + U, 5.40 mesh 0 to 15% of 15% tl, 5.40 mesh + U, 5.50 mesh O ~ 25% coarse piece U-8, 50J So') Yu+U-3.65 mesh 0-40% fine pieces U, S, 65 10 meshes, S, 100 meshes, 0-25%, 25% U, 5.100 10 meshes, 5.150 meshes 0-10% finest pieces U, 3.150 meshes 2~20% magnesium oxide (MgO) particles are thoroughly kneaded, and then Mixed with organic binder and/or water to maintain stable shape after molding. molding operation The manufacturing process may include air-tamping, vibratory casting, mechanical or isostatic pressing, or the manufacture of refractory products. There are other techniques well known in the art of construction. Then dry or cure the molded part followed by firing to a sufficiently high temperature to sinter the magnesium oxide particles together and strengthen them. form a strong shape. Drying and baking can also be accomplished by conventional known methods.

After firing, the core 12 is machined or formed into the desired size and shape. Cha The channels 24, 26, 28, 30 are formed into the core 12 during the molding process, but are preferred according to the present invention. In a preferred embodiment, core 12 is machined after firing.

In the illustrated embodiment, the core 12 is 14 1/2 inches long and has an outer diameter of 7 mm at one end. The diameter at the other end varies from 3/16 inch to 7 7/16 inch. hole or open The mouth 18 has a diameter of approximately 3 inches. Of course, the size or shape of the core 12 The shape is not critical to the invention and many varying sizes and shapes may be advantageous. Applicable to

The general shape of nozzle 10 and/or core 12 will depend on the particular casting machine utilized. or determined by the system. As shown in the dimensions above, the core 12 is It has a slightly conical shape, that is, it extends slightly outward from top to bottom. ing. This shape is intended to facilitate the assembly of the nozzle 10, as will be described later. However, it is not critical to the invention.

The housing 14 has a generally cylindrical shape, and its inner surface 32 corresponds to the outer profile of the core 12. Have dimensions that closely match and match the file. The threaded fitting 34 ging 14. An opening 36 extends through fitting 34 and housing 14. will be established. The distance between the housing 14 and the core 12 is approximately 0.06 to 0.20. In, a uniform space or gap 38 is defined. thin uniform An adhesive refractory mortar layer 40 is provided in said space or gap 3B to secure the housing. The ring 14 is fixed to the refractory core 12.

Commonly known air-dried mortars or phosphoric acid-containing mortars are utilized. Attached Tool 34 is positioned on housing 14 to secure housing 14 to core 12. so that the aperture 36 is aligned with one of the channels 24.26.28.30 when configured. Housing 14 essentially surrounds core 12 and includes mortar 40. , the core 12 is structurally reinforced, as will be described in detail later. Housing 14 and mole The barrel 40 is the area around the core 12 and the open portion of the channel 24, 26, 28, 30. A seal is formed on top. In other words, what is the housing 14 and the mortar 40? As best shown in Figure 3, an overall airtight barrier is formed over each channel. Ru.

In the illustrated embodiment, housing 14 is formed from low carbon steel and has a diameter of 0.05 in. Has uniform wall thickness. Housing 14 is 141/2 in. long and has a and an outer diameter varying from 7 1/2 inches at one end to 7 3/4 inches at the other end. have

An important aspect of the invention is the assembly of nozzle 10. Read the specification on this point. As will become clear as we proceed, for the operation of the nozzle 10, the channel 24.26.28.30 are kept "open" during assembly and blocked by mortar 40. It is important that you do not give up. The simplest way to assemble the nozzle 12 is to assemble the nozzle By coating 12 with mortar and sliding the housing 14 on top of it, be. However, the problem with this method is that the housing 14 and the core 12 The relatively small gap between the , creating a large fluid pressure in the mortar 40, which causes the mortar to form in the nozzle 12. There is a possibility of pressure fitting into the channel 24.26.28.3o . This problem can be solved by covering the channel with a positionally stable barrier or by More importantly, the width dimension of the channel is determined by the fluid pressure at which the barrier is generated. This can be overcome by selecting a material that can withstand pressure and not be forced into the channel. . In this regard, adhesive tape 42, such as commonly known duct tape, may be used. Used to cover channels, reduce channel width to 1/2 inch, smaller If maintained, regardless of the size of the nozzle 14, the housing 14 is 4o will not press into the channel 24.26.28.30 and cause any obstruction. It is clear that the core 12 can be slid on the core 12 in the same manner. In the illustrated embodiment, the channel The channels 24.26.28 have a width of approximately 1/4 inch and a depth of 1/2 inch. Channel 30 has a width of 1/2 inch and a depth of 1/2 inch. Tape 42 is A long T-shaped member (not shown) is attached to the brif to prevent it from being press-fit into channel 3o. It is inserted into the channel 30 as a screw member. To make this assembly even easier, As mentioned above, the core 12 and the inner surface 32 of the housing 14 are Slightly conical as shown. The assembly is complete and the refractory mortar is solidified. mortar 4o which prevents communication with channel 24.26.28.30 after Alternatively, the openings 36 may be formed by machining the tape 42.

Therefore, referring to the operation of the present invention, the nozzle 1o melts into the next operation process in the steel making process. Configured for use in a tundish for delivering metal flow. Nozzle 10 flanges to facilitate assembly on the tundish in the usual known manner. or with other positioning surfaces. The present invention is limited to nozzles of a particular shape or size. It is understandable that this is not specified. In this regard, the physical dimensions of the nozzle and The shape is determined by the particular casting machine or system in which it is used. is well known. Attachment 34 is connected to a source of inert gas in a conventional and known manner. Fixed. Inert gas is passed from fitting 34 into channel 24 and out of the chamber. from channel 30 into channel 26.28. Inert gas pressure, impermeable Unique to Magnesium Oxide (MgO) Core 12 (Overcome DtllEtfc) gas flows from the core 12 into the nozzle opening or hole 18. do. As mentioned above, the typical flow rate of inert gas in the nozzle is 5-10 psi. The pressure is approximately 15 standard cubic feet per hour. The important point is that the present invention channels 24.26.2 on the outer surface of the core 12 at a location adjacent to the desired location. 8 to direct the inert gas flow to a specific desired location within the nozzle opening 18. It is to be sent to the highest rank. In this regard, the inert gas flow through the nozzle wall It is known that this occurs most frequently in areas adjacent to the channel location. Therefore, the nozzle is A flow of inert gas is directed within the hole or opening 18 to the areas where impurity deposition is most severe. (i.e., the channels are located in the core 12). rephrase , channels 24, 26, 28, 30 at specific locations in core 12 have maximum gas pressure. It allows for a high degree of control over the area within the aperture 18 that it is desirable to have. Inside hole 18 The maximum gas pressure of is adjacent to the location of the channel in core 12, but as previously described The refractory core has fine continuous porosity, allowing extremely uniform inert gas distribution. is provided throughout the aperture 18 of the nozzle 10.

The nozzle of the present invention has been shown to have an increased operating life and substantially improved corrosion resistance. has been done. Additionally, this type of nozzle can be made of alumina, titania and/or other Showing significant improvement against deposits. A salient feature of the invention is that multiple This is the result of the tar. By applying magnesium oxide when forming the core. , has no affinity for alumina or other impurities contained in steel. A new core is provided. The good porosity property of the core, namely fine continuous porosity, makes the melting A small microscopic barrier maintains a small gas gap between the metal and the inner surface 20 of the hole 18. It is believed to generate bulls. Relatively high backpressure is required for molten metals and refractory materials. This helps maintain a uniform layer of gas bubbles between the surfaces. The important point is disclosure The ability of the nozzle to deliver maximum gas flow to a specific location within the nozzle hole may be affected by deposits. The goal is to provide maximum gas flow to the area where it is likely to be exposed. The nozzle of the present invention An additional advantage is that in addition to the sealing core 12, the housing 14 relative to the core 12 installation conditions, there is a possibility that the nozzle of the present invention will be seriously damaged by cracks. I'm keeping it small. In this regard, the housing 14 is made of magnesium oxide (Mg O) Hold the refractory materials together like a reinforcing band, thus reducing the consequences of thermal shock. As a result, it prevents crank opening that occurs in refractory materials.

The invention has been described in connection with preferred embodiments. Description and claims It will be obvious from the description that modifications and changes will occur to those skilled in the art. Ta For example, the present invention relates to the use of magnesium oxide in forming the core 12. Although described, other materials can be utilized to provide a permeable core, or Other embodiments of the invention may also be advantageously applied. Additionally, the present invention has been described herein. The shape and size of the channel are not limited. Limit channel width It is also clear that other methods of assembling the nozzle 10 may be provided within the scope of the present invention. Will. For example, a metal tape strip on channel 24.26.28.30 A wide channel can be used by using the top. Fix all these , modifications are within the scope of the invention as long as they are within the scope of the claims or equivalents thereof. It is considered to be within the range.

FIG.2 4.4. -2- Heisei Year Month Day

Claims (12)

[Claims] 1. a long nozzle body formed from a gas permeable porous refractory material, a conduit extending longitudinally therethrough; an inner surface defining the conduit; an outer surface defining a predetermined body profile; a long nozzle body having a channel device; a metal having an inner surface sized to substantially match the profile of the nozzle body; Made of housing; A device for fixing the housing to the nozzle body, the housing being surrounding the nozzle body, the fixing device being between the housing and the nozzle body; forming a relatively airtight layer fixed to the nozzle, the channel device forming a relatively airtight layer fixed to the nozzle; a fastening device forming an internal passageway in the channel; a port device in the housing connected to an inert gas supply; , a port device for forcing the gas into the passageway and into the porous refractory material; Immersion nozzle for continuous metal casting. 2. The nozzle body has a generally cylindrical shape, and the channel device forms a peripheral edge of the nozzle body. The nozzle according to claim 1, having an annular groove of a predetermined shape arranged in the nozzle. 3. The method of claim 1, wherein the fixing device is a refractory cement mortar. Cheating. 4. Claim 1, wherein the nozzle body mainly consists of magnesium oxide particles. Nozzle as described in section. 5. Claim 1, wherein the nozzle body has a porosity of 20% to 30%. nozzle. 6. an elongated body of porous refractory material having an outer surface, an inner surface and a body extending through the body; an elongated body having a longitudinally extending hole, said hole defining said inner surface; and a metal housing surrounding said outer surface of said body. a gas-permeable nozzle connected to an inert gas source to a nozzle, wherein the gas flows through the body from the outer surface to the inner surface; , a device for directing a bulk gas flow through the nozzle body to a specific location on the inner surface of the hole; Nozzle equipped with. 7. The device for directing the gas flow comprises channels formed in the outer surface of the elongated body. the channel can be connected to the inert gas source, and the inert gas is connected to the inert gas source; Claim 6, wherein the liquid flows into the main body only from the channel. nozzle. 8. the elongated body has a predetermined external profile, and the channel extends through the body; formed on an outer surface, the metal housing substantially conforming to the profile of the body; and wherein said housing has a thin layer of refractory mortar to accommodate said book. 8. A nozzle according to claim 7, which is fixed to the body. 9. Claim 6, wherein the main body is made of magnesium oxide (MgO) particles. Included nozzle. 10. having a predetermined external shape consisting essentially of magnesium oxide (MgO) particles an elongated porous body having an inner surface, an outer surface extending longitudinally through the body, and having an inner surface and an outer surface extending longitudinally through the body; a hole defining a surface, an inner surface substantially conforming to said outer shape of said body; metal housing with a surface, the metal housing is secured to the elongate body to form an airtight seal therebetween; Device, a device for connecting the nozzle to a source of inert gas and directing said gas through said porous body; a device for feeding the inner surface of the hole through the hole; Immersion nozzle for continuous metal casting. 11. The gas delivery device connects the outer surface of the body and the inner surface of the metal housing. The infiltration nozzle according to claim 10, which is a channel formed between a surface and a surface. . 12. The nozzle is made of magnesium oxide (MgO) particles of the following size: Immersion nozzle according to claim 10: 0.125''+U. S. 40 mesh 　　　　　　　　　-15%U. S. 40 mesh + U. S. 50 mesh 0-2 5%U. S. 50 mesh + U. S. 65 mesh 0-40% U. S. 65 Mesh + U. S. 100 mesh 0-25% U. S. 100 mesh + U. S. 150 mesh 0-10%U. S. 150 mesh 0-20%13. a. A porous material with channels of a predetermined width formed on its outer surface. form a fire nozzle; b. having an inner surface dimensioned to match the outer profile of the porous refractory nozzle; a metal receiving said nozzle with a small space interposed therebetween and having an orifice on the side; forming a housing made of c. Positionally stabilize the channel in the nozzle cover with a barrier, d. the refractory nozzle within the housing and a refractory cement mold disposed between the refractory nozzles; A method for manufacturing an infiltration nozzle, comprising: inserting it through a barrel.