JP5549385B2 - Refractory lining structure of induction heating device placed in storage furnace - Google Patents

Description

  The present invention relates to a refractory lining structure for an induction heating apparatus for heating hot metal, which is disposed in a storage furnace for temporarily storing blast furnace hot metal or chromium-containing hot metal.

  The blast furnace hot metal discharged from the blast furnace and the chromium-containing hot metal output from the smelting reduction furnace of chrome ore are received in hot metal transfer containers such as topped cars and hot metal ladles, and desulfurization and dephosphorization as required. After being subjected to the preliminary treatment, it is transported to the converter and decarburized and refined in the converter. At this time, before decarburizing and refining in the converter to adjust the excess or deficiency of hot metal caused by fluctuations in the output timing of the blast furnace and smelting reduction furnace and the processing amount in the converter, or to uniformize the hot metal components The hot metal may be temporarily stored in a storage furnace.

  The hot metal in the storage furnace causes a temperature drop due to heat radiation from an opening such as a tap and heat removal by a refractory, so an induction heating device having a groove type flow path (also referred to as a “groove type induction heating device”). Is provided in the storage furnace, and the hot metal is heated by the groove type induction heating device (see, for example, Patent Document 1 and Patent Document 2).

  An example of a storage furnace provided with a grooved induction heating device is shown in FIG. In FIG. 1, reference numeral 1 is a storage furnace, 2 is a hot water outlet, 3 is a hot metal inlet, 4 is a work port, 5 is a grooved induction heating device, 6 is hot metal, 7 is a furnace body, and 8 is a refractory layer. In addition, one or a plurality of the groove type induction heating devices 5 are arranged on the side surface of the furnace body 7, and the groove type induction heating device 5 usually has a structure that can be separated from the furnace body 7.

  FIG. 2 shows a schematic perspective view of the groove type induction heating device 5, FIG. 3 shows a schematic side sectional view seen from the X direction of FIG. 2, and FIG. 3 shows a schematic sectional view taken along the arrow line YY ′ of FIG. 4 shows.

  As shown in these drawings, the grooved induction heating device 5 accommodates a lining refractory material 10 that includes a flow path 11, a flow path 12, and a flow path 13 that are paths through which the molten iron 6 passes. An induction coil 14 in which a coil is wound around an iron core is disposed in a steel casing 9, and the flow paths 11, 12, and 13 communicate with the interior of the furnace body 7. By causing an alternating current to flow through the induction coil 14, an alternating magnetic flux interlinking with the flow paths 11, 12, and 13 is generated, and an induced current is generated in the molten iron 6 in the flow path by the alternating magnetic flux, and a joule due to the induced current is generated. This is an apparatus for heating the hot metal 6 by heat. In addition, Lorentz force (electromagnetic force) acts on the hot metal 6 in the flow path by the induction current and the alternating magnetic flux generated by the induction coil 14, and the hot metal 6 flows from the flow path 11 toward the flow path 12 and the flow path 13. Form.

  As the lining refractory 10 to be applied to the casing 9, a magnesia-based refractory is often used in order to ensure corrosion resistance. In order to prevent digestion of the magnesia-based refractory, a ramming construction material that can be constructed anhydrously is used. Anhydrous castable refractories are used. When constructed with these non-standard refractories, joints (the joints between bricks and bricks) do not exist, and joints are generally easily damaged. Therefore, regular bricks (also called "standard refractories") are used. Compared to the case of construction, there is an advantage that troubles such as electrical grounding and electric leakage in the induction coil 14 due to the penetration of molten metal into the joint are less likely to occur. However, on the other hand, these irregular refractories cause cracks within a certain period due to vibration and thermal history, and therefore the penetration of the hot metal 6 into the cracked part cannot be prevented.

  Further, the lining refractory 10 to be constructed on the casing 9 is sintered and increased in strength by the heat of the hot metal 6 passing through the flow paths 11, 12, 13. At the outer peripheral part, which is far away, the state is merely filled with a non-sintered refractory having little strength. In particular, as shown in FIGS. 3 and 4, the casing 9 has a break in the casing 9 between the opposing induction coils 14 (outside portion of the flow path 11) due to electromagnetic characteristics (for preventing magnetic flux shortcuts). In other words, a gap portion 15 (referred to as “casing gap portion 15”) in which the iron skin is not installed is provided, and this portion is an unsintered refractory material with insufficient strength. When the crack reaches this part and the hot metal 6 enters, a trouble of leakage of the hot metal 6 from the casing gap 15 occurs.

JP 2004-218038 A JP 2008-180452 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an induction heating device installed in a storage furnace with a flow path of the induction heating device made of a ramming material or an anhydrous castable refractory. An object of the present invention is to provide a refractory lining structure for an induction heating apparatus that can prevent molten metal leakage trouble even if a crack occurs in the lining refractory for forming.

  In order to solve the above-mentioned problems, the present inventors disassembled the induction heating device after use, and investigated and examined it.

  As a result, although it was found that cracks occurred in various places in the lining refractory in the casing, the only place where the molten metal leaked was the gap between the casings, which was the cut of the iron skin. Except for the gap in the casing, when the hot metal that has penetrated the cracks in the lining refractory comes into contact with the steel casing, it is cooled and solidified by the casing, thereby stopping the movement of the hot metal in the cracks and extending further. It was found that it does not lead to hot metal leakage.

  Conventionally, a fire-resistant board has been constructed between the casing and the lining refractory, but it has been found that the fire-resistant board has insufficient corrosion resistance to hot metal. Therefore, by installing fixed bricks such as molded bricks with corrosion resistance on the outside of the refractory lining, the hot metal that has entered the cracks solidifies in contact with the fixed brick, preventing leakage of hot metal even in the gap between the casings. I learned that I can do it.

  The present invention has been made on the basis of the above knowledge, and the refractory lining structure of the induction heating device arranged in the storage furnace according to the first invention is the refractory of the induction heating device arranged in the storage furnace. Medium lining structure between a steel casing which is an outer shell of an induction heating device and a lining refractory made of a ramming construction material or an anhydrous castable refractory constructed on the inner surface side of the casing. Or basic shaped bricks are arranged.

  In the refractory lining structure of the induction heating device disposed in the storage furnace according to the second invention, in the first invention, a heat insulating material is further disposed between the casing and the shaped brick. It is characterized by.

  The refractory lining structure of the induction heating device arranged in the storage furnace according to the third invention is characterized in that, in the first or second invention, the shaped bricks are arranged in two or more layers.

  According to the present invention, a neutral or basic shaped brick is placed on the back of a lining refractory made of a ramming construction material or an anhydrous castable refractory, so that a crack occurs in the lining refractory, and hot metal is generated in this crack. Even if it penetrates, the hot metal that has penetrated the crack is cooled by the regular brick and solidifies when it comes into contact with the regular brick, which stops the movement of the hot metal in the crack, so even in the gap between the casings, Leakage is prevented, and the induction heating device can be stably operated.

It is a schematic perspective view of the storage furnace provided with the groove type induction heating apparatus. It is a schematic perspective view of the groove type induction heating apparatus shown in FIG. FIG. 3 is a schematic side cross-sectional view seen from the X direction of FIG. 2. It is a schematic sectional drawing by the Y-Y 'arrow of FIG. It is a schematic sectional drawing which shows the refractory lining structure of the groove type induction heating apparatus which concerns on this invention.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of a storage furnace to which the present invention is applied, which is provided with a grooved induction heating device, and shows a section obtained by cutting a part of the storage furnace.

  As shown in FIG. 1, a storage furnace 1 to which the present invention is applied has a tiltable cylindrical furnace body 7, and a grooved induction heating device 5 is used as a heating means for the hot metal 6, as a side wall of the furnace body 7. 1 or 2 or more units are provided in the. The storage furnace 1 includes a hot metal inlet 3 for charging molten iron 6 supplied from a blast furnace or a smelting reduction furnace into the furnace body 7 and a hot water outlet 2 for discharging the stored molten iron 6 by tilting. I have. Also, there is one openable work port 4 for inspection in the furnace, sampling from the furnace body 7, or charging of auxiliary materials (such as ironmaking agent, alloy iron or iron scrap) into the furnace body 7. One or more are provided, and a refractory layer 8 is applied to the inside of the iron shell of the furnace body 7. The hot metal 6 to be stored is a blast furnace hot metal, a chromium-containing hot metal or the like, and the outer shell of the furnace body 7 is made of an iron shell.

  FIG. 2 shows a schematic perspective view of the groove type induction heating device 5, FIG. 3 shows a schematic side sectional view seen from the X direction of FIG. 2, and FIG. 3 shows a schematic sectional view taken along the arrow line YY ′ of FIG. 4 shows. As shown in these figures, the groove-type induction heating device 5 sandwiches the flow path 11 in a steel casing 9 in which the lining refractory 10 constituting the flow path 11, the flow path 12 and the flow path 13 is accommodated. Thus, an induction coil 14 having a coil wound around an iron core is disposed so as to face each other, and the flow paths 11, 12, and 13 communicate with the inside of the furnace body 7. Although not shown, the iron cores facing each other across the flow path 11 are connected to the outside of the casing 9 and have a rectangular integrated structure. The casing 9 has a break of the casing 9 between the opposing induction coils 14, which is a portion corresponding to the outside of the flow path 11, in terms of electromagnetic characteristics (for preventing magnetic flux shortcuts), that is, an iron skin. A casing gap 15 that is not installed is provided.

  By passing an alternating current through the induction coil 14, an alternating magnetic flux interlinking with the loop-shaped flow paths 11, 12, and 13 is generated from the induction coil 14, and this alternating magnetic flux induces the hot metal 6 in the loop-shaped flow path. This is an apparatus that generates a current and heats the molten iron 6 by Joule heat generated by the induced current. Also, the Lorentz force (electromagnetic force) acts on the hot metal 6 in the flow path due to the induction current and the alternating magnetic flux generated by the induction coil 14, and the hot metal 6 moves in a direction opposite to the direction toward the furnace body 7. It flows in the opposite direction, branches into the flow path 12 and the flow path 13, and forms a circulation flow that returns to the furnace body 7 through the flow path 12 and the flow path 13.

  The refractory lining structure of the grooved induction heating device 5 configured as described above will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view showing the refractory lining structure of the grooved induction heating device 5 according to the present invention, and is a cross-sectional view of the grooved induction heating device 5 viewed from the same direction as FIG.

  A heat insulating material 17 such as a refractory board is disposed over the entire inner surface of the casing 9, and one or more layers of the bricks 16 are constructed inside the heat insulating material 17. The molded brick 16 is flat and the material is neutral (alumina, alumina-SiC, etc.) or basic (magnesia, magnesia-chrome, etc.). In this case, in order to reliably prevent the molten iron 6 from leaking, it is preferable to arrange the molded bricks 16 in two or more layers, and in the case of arranging in two or more layers, joints are alternately arranged (“staggered arrangement”). And prevent joints from penetrating. Then, a ramming construction material made of magnesia-based refractory or an anhydrous castable refractory is applied as the lining refractory 10 inside the molded brick 16. In this case, for example, a steel pipe is disposed at a position to be the flow path 11, the flow path 12, and the flow path 13, and a ramming material or an anhydrous castable refractory is applied.

  After the ramming construction material or anhydrous castable refractory constructed as the lining refractory 10 is dried and sintered to some extent, the groove type induction heating device 5 is attached to the furnace body 7, and the groove type induction heating device 5 Start using. By passing the hot metal 6 from the furnace body 7 through the grooved induction heating device 5, the disposed steel pipe is melted and the flow paths 11, 12, 13 are formed. In addition, as the hot metal 6 passes through the flow paths 11, 12, and 13, sintering of the ramming construction material and the anhydrous castable refractory proceeds by the heat of the hot metal 6, and a firm lining refractory 10 is formed. In addition, although it is preferable to install the heat insulating material 17 in order to reduce the temperature drop of the hot metal 6, it may not be installed.

  By applying the refractory for the grooved induction heating device 5 in this way, a crack occurs in the lining refractory 10, and even if the crack corresponds to the position of the casing gap 15, Since the molded brick 16 exists on the back side, it is possible to prevent the molten iron 6 from leaking from the casing gap 15.

  Specifically, when the molded brick 16 was not arranged, there was a leakage trouble of the hot metal 6 from the casing gap 15 at a frequency of about once every two years, but by applying the present invention, There was no leakage of hot metal 6.

DESCRIPTION OF SYMBOLS 1 Storage furnace 2 Hot water outlet 3 Hot metal apparatus inlet 4 Work inlet 5 Groove type induction heating apparatus 6 Hot metal 7 Furnace body 8 Refractory layer 9 Casing 10 Lined refractory 11 Flow path 12 Flow path 13 Flow path 14 Inductive coil 15 Casing gap Part 16 Molded brick 17 Heat insulation

Claims (2)

A refractory lining structure of the induction heating device relative to the arranged configuration of the induction coil across the貯銑furnace flow path of the loop-shaped hot metal communicating with the interior of an outer shell of the induction heating device A steel casing is provided on the outside of the hot metal flow path between the opposing induction coils so as to have a casing gap portion in which no iron skin is installed,
A neutral or basic shaped brick is disposed between the casing and a magnesia-based lining refractory made of a ramming construction material or an anhydrous castable refractory, which is constructed on the inner surface side of the casing. A refractory lining structure for an induction heating device disposed in a storage furnace, wherein a heat insulating material is disposed between the refractory brick and the fixed brick . The refractory lining structure for an induction heating apparatus disposed in a storage furnace according to claim 1, wherein the regular brick is disposed in two or more layers.

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