JP2010065949A - Manhole closure wall for vertical melting furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manhole closure wall capable of suppressing abrasion of a furnace inner closure wall of a manhole and improving productivity of a vertical melting furnace. <P>SOLUTION: This manhole closure wall of the vertical melting furnace as a furnace wall for closing the manhole of the vertical melting furnace, includes (i) a refractory wall constructed by stacking high heat-conductive refractory while applying an alumina refractory material as a joint filling material, and (ii) a cooling panel mounted on a surface of the refractory wall. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a furnace wall excellent in wear resistance that closes a manhole formed in a furnace wall of a hot water reservoir of a vertical melting furnace.

  Conventionally, an iron source mainly composed of iron scrap, foundry scrap, pig iron, etc., which has a higher metalization rate than iron ore (iron source with a high metalization rate), has a small internal volume compared to a blast furnace. Pig iron is produced by melting in a furnace. In recent years, iron sources such as dust agglomerates and self-reducing ores (agglomerated minerals with a high carbonaceous material content) in addition to iron sources with a high metallization rate. Several operation methods for producing pig iron using a source (iron source having a low metallization rate and requiring reduction) have been proposed (see Patent Documents 1 to 3).

  To promote both melting of the iron source and reduction of the iron source (iron oxide) in the furnace, the iron source is melted in the furnace while compensating for the endotherm associated with the generation of the reducing gas. Although it is necessary to supply a sufficient amount of heat, in recent years, with the increase in the size of the vertical melting furnace, the amount of heat supplied increases and the thermal load on the furnace wall tends to increase.

  Also, as the size of the vertical melting furnace increases, the weight of the hot metal produced increases, so the hot water reservoir is subjected to a thermal load more than before and is eroded by the hot metal to repair the furnace wall and furnace bottom. Increase the frequency of As a result, the productivity of the vertical melting furnace decreases.

  In Patent Document 4, in order to prolong the operation time, it is proposed to flow water on the surface of the furnace body to reduce the thermal load of the furnace body and suppress the wear of the furnace wall. In the proposal, since the region where water flows is limited to the upper region of the hot water reservoir due to the structure, it is not possible to cope with wear of the furnace wall of the hot water reservoir due to hot metal erosion.

Japanese National Publication No. 01-501401 Japanese Patent Application Laid-Open No. 10-036906 JP 09-203584 A JP 2002-147959 A

  In the vertical melting furnace, the furnace wall of the hot water reservoir is blown to the opposite side of the tap outlet to remove the coke and refractories, and to repair the furnace wall and hearth. A hole of about 1 m in length (commonly referred to as “rear manhole”, but may be simply referred to as “manhole” hereinafter) is formed, and is closed with a refractory during operation.

  Usually, in order to prevent overheating of the furnace body, water is sprayed on the surface of the furnace body and cooled, but the furnace body has a structure in which water does not flow on the surface of the closed wall of the manhole. However, wear due to excessive heat load and hot metal erosion was fast, and the frequency of repairs and repairs increased, which hindered productivity.

  An object of the present invention is to suppress the wear of the manhole inner closed wall of the manhole and to improve the productivity of the vertical melting furnace, and to provide a manhole closed wall that solves the problem.

  The inventor has intensively studied a means for suppressing the wear of the manhole inner wall of the manhole. As a result, it was found that if the manhole is closed with a highly heat-conductive refractory, and the water-cooled panel is attached to the refractory wall and cooled, excessive heat load and wear of the manhole closed wall due to hot metal erosion can be suppressed. did.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

(1) A furnace wall for closing a manhole of a vertical melting furnace,
(I) a refractory wall constructed by stacking high thermal conductivity refractories using alumina refractories as joint materials;
(Ii) a cooling panel attached to the surface of the fire wall,
A manhole closing wall of a vertical melting furnace characterized by comprising:

  (2) The manhole closing wall of the vertical melting furnace as described in (1) above, wherein the fire wall has a three-layer structure in the core direction.

  (3) A manhole closing wall for a vertical melting furnace as described in (1) or (2) above, wherein a highly heat conductive refractory material is press-fitted between the refractory wall and the cooling board.

  (4) The manhole obstruction wall of the vertical melting furnace according to any one of (1) to (3), wherein the periphery of the cooling plate is surrounded by a heat-resistant patching material.

  (5) The manhole obstruction wall of the vertical melting furnace according to any one of (1) to (4), wherein the cooling plate is made of copper.

  (6) The manhole blocking wall of a vertical melting furnace as described in any one of (3) to (5) above, wherein the high thermal conductivity refractory is a refractory excellent in spall resistance .

  (7) The manhole closing wall of the vertical melting furnace according to any one of (3) to (6), wherein the high thermal conductivity refractory is an alumina brick or a refractory stamp block.

  (8) The manhole of the vertical melting furnace according to any one of (3) to (7), wherein the thermal conductivity of the high thermal conductivity refractory is 4 W / m · K or more. Occlusion wall.

  (9) The manhole obstruction wall of the vertical melting furnace according to any one of (3) to (8), wherein the high thermal conductivity refractory material is a silicon carbide refractory material.

  According to the present invention, it is possible to reduce the frequency of repair and renovation by suppressing excessive heat load and wear of the manhole clogging wall due to hot metal erosion, and as a result, the productivity of the vertical melting furnace is remarkable. Can be increased.

  The present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of a vertical melting furnace employing the manhole-closed heat-resistant wall of the present invention. The vertical melting furnace A includes a furnace bottom portion 2 having a tap hole 3, a furnace body 1 having tuyere 10 and tuyere 11 on a lower furnace wall, a gas suction unit 4 having a gas suction port 5, and a housed iron source. It is comprised from the furnace top part 6 which seals a furnace top, and the charging part 7 which inserts the iron source 8 in a furnace. In addition, although the vertical melting furnace shown in FIG. 1 is provided with two tuyere, the tuyere may be one stage.

  Hot air is sent from the tuyere 10 and cold air is sent from the tuyere 11 into the furnace to secure the amount of heat necessary for melting the iron source and the reducing gas necessary for reducing the iron source.

  A coke bed 9 is formed at the bottom of the furnace body 1. The molten iron produced by melting and / or reducing while the iron source 8 is lowered further descends the coke bed 9 and is stored as molten iron 12 in the hot water reservoir 13. The hot metal 12 is appropriately discharged from the outlet 3.

  In the furnace wall 14 that forms the hot water reservoir 13, a manhole 15 is formed in the furnace wall 14 on the side opposite to the tap outlet 3. A work floor 23 including a protection plate 22 and a water shielding plate 24 are attached to the furnace wall of the manhole.

  In the conventional vertical melting furnace, the manhole is closed with a heat-resistant refractory, but the refractory is worn by a heat load or the erosion action of the hot metal.

  On the other hand, in the present invention, a highly heat conductive refractory excellent in spall resistance is piled up using an alumina refractory material as a joint material, and a fire wall 16 for closing the manhole 15 is constructed. A water-cooled platen 17 was attached.

  FIG. 2 shows a detailed embodiment of the manhole blocking wall of the present invention. 2A shows a vertical sectional structure of the manhole blocking wall, and FIG. 2B shows an AA sectional structure of the vertical sectional structure.

  The refractory wall 16 that closes the manhole 15 formed in the furnace wall 14 of the hot water reservoir is constructed by stacking high heat conductive refractories 16z using alumina refractory as a joint material. The fire wall 16 shown in FIG. 2A has a three-layer structure of a furnace inner fire wall layer 16a, an intermediate fire wall layer 16b, and a fire wall wall 16c outside the furnace.

  In FIG. 3, the BB cross-section of the furnace inner side fire wall layer 16a is shown. As shown in FIG. 3, the high heat conductive refractories 16z are stacked in a staggered arrangement. In addition, a burner hole 25 for glowing coke is formed in the lower part of the fireproof wall 16a. The burner hole 25 is closed with the high thermal conductivity refractory 1.

  Similarly, the intermediate fire wall layer 16b and the fire wall layer 16c on the outside of the furnace are stacked in a staggered arrangement, but as shown in FIG. It is preferable that staggered stripes are also arranged between the layers.

  The high thermal conductivity refractory 16z may be any refractory having high thermal conductivity and is not particularly limited in terms of material. However, the refractory having excellent spall resistance, in particular, thermal conductivity of 4 W / m · K or more. Refractories are preferred. In terms of material, alumina brick or refractory stamp block is preferred.

  In the present invention, as shown in FIGS. 2A and 2B, a cooling plate 17 having a square seat 18 and a cooling water port 19 is attached to the furnace outer surface of the refractory wall 16. When the cooling panel 17 is attached, the high heat conductive refractory material 20 is pressed into the gap between the cooling board 17 and the refractory wall 16 to fill the gap, and the cooling panel 17 and the refractory wall 16 are brought into close contact with each other.

  The high thermal conductivity refractory material 20 may be a high thermal conductivity refractory material, and is not particularly limited in terms of material, but is preferably a silicon carbide refractory material in terms of heat resistance.

  Further, a heat-resistant patching material 21 is filled around the cooling plate 17 to fill a gap between the cooling plate 17 and the furnace wall. The heat-resistant patching material 21 may be any heat-resistant refractory material and is not particularly limited in terms of material, but is preferably made of the same material as the high thermal conductivity refractory 16z.

  FIG. 4 shows a CC cross-sectional structure of the vertical cross-sectional structure of the manhole blocking wall shown in FIG. In order to reduce the thermal load on the furnace wall, water may be sprinkled on the furnace body, but the water flowing down the furnace body surface is blocked by the water shielding plate 24, so that the cooling plate 17 and the work floor 23 may not get wet. Absent.

  The cooling board is preferably made of copper in terms of thermal conductivity. FIG. 5 shows an aspect of the cooling panel. Fig.5 (a) shows the plane aspect of a cooling disc, FIG.5 (b) shows the side aspect. As shown in FIG. 5, the cooling board 17 is configured by attaching a cooling water channel board 17a to the back surface of the metal plate 17b.

  As shown in FIG. 5A, the cooling water supplied from the left cooling water port 19 flows through the cooling water channel formed in the vertical direction and is discharged from the right cooling water port 19.

  Although FIG. 5 shows a cooling plate having a vertical cooling water channel, the cooling water channel may be formed in the horizontal direction.

  In the present invention, since the fire wall that closes the manhole is cooled by the cooling plate, the heat load on the fire wall and the erosion action of the hot metal can be reduced, and the wear of the fire wall can be suppressed.

  Next, examples of the present invention will be described. The conditions of the examples are one example of conditions adopted for confirming the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. Is not to be done. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

(Example)
A SiC stamp block (alumina: 69%, SiC: 23%, C: 3%) as a high thermal conductivity refractory, and a high alumina refractory material with excellent corrosion resistance, heat resistance and oxidation resistance as a joint material ( A fireproof wall was constructed in the manhole of the vertical melting furnace using alumina mortar and alumina (90%).

  A copper cooler is attached to the outer surface of the furnace wall of the fire wall, and a high heat conductive fire-resistant material (SiC press-fit material, SiC> 60%) is pressed into the gap between the cooler wall and the fire wall to surround the copper cooler. The company started the operation by embedding a SiC stamp material to complete the closed wall of the manhole.

  The wear rate of the refractory wall was about 3.0 mm / 1000 t.

  It can be seen that the wear rate is improved by 1.5 mm / 1000 t compared to the wear rate of about 4.5 mm / 1000 t when operating without a cooling panel. As described above, according to the present invention, even when performing a high production operation of a vertical melting furnace, it is possible to suppress the wear of the manhole closed wall due to excessive heat load and hot metal erosion, and to reduce the frequency of repair and repair. Can do.

  As described above, according to the present invention, excessive heat load and wear of the manhole blockage wall due to hot metal erosion are suppressed, the frequency of repair and repair is reduced, and the productivity of the vertical melting furnace is remarkably increased. Can be increased. Therefore, the present invention has great applicability in the pig iron manufacturing industry.

It is a figure which shows the one aspect | mode of the vertical melting furnace provided with the manhole obstruction | occlusion wall of this invention. It is a figure which shows the structure of the manhole obstruction | occlusion wall of this invention. (A) shows a vertical cross-sectional structure, and (b) shows a cross-sectional structure taken along line AA of the vertical cross-sectional structure. It is a figure which shows the cross section in the BB line of the perpendicular | vertical cross-sectional structure shown to Fig.2 (a). It is a figure which shows the cross section in CC line of the perpendicular | vertical cross-sectional structure shown to Fig.2 (a). It is a figure which shows the one aspect | mode of a water cooling board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Furnace bottom part 3 Outlet 4 Gas suction part 5 Gas suction part 6 Furnace top part 7 Charging part 8 Iron source 9 Coke bed 10, 11 tuyere 12 Hot metal 13 Hot water storage part 14 Furnace wall 15 Manhole 16 Fire wall 16a, 16b, 16c Refractory wall layer 16z High heat conductivity refractory 17 Cooling panel 18 Square seat 19 Cooling water port 20 High heat conductivity refractory material 21 Heat resistant patching material 22 Guard plate 23 Work floor 24 Water shield plate 25 Burner hole

Claims (9)

A furnace wall that closes the manhole of a vertical melting furnace,
(I) a refractory wall constructed by stacking high thermal conductivity refractories using alumina refractories as joint materials;
(Ii) a cooling panel attached to the surface of the fire wall,
A manhole closing wall of a vertical melting furnace characterized by comprising:   2. The manhole closing wall of a vertical melting furnace according to claim 1, wherein the refractory wall has a three-layer structure in the core direction.   The manhole closing wall of a vertical melting furnace according to claim 1 or 2, wherein a high thermal conductivity refractory material is press-fitted between the refractory wall and the cooling panel.   The manhole obstruction | occlusion wall of the vertical melting furnace of any one of Claims 1-3 with which the circumference | surroundings of the said cooling board are surrounded by the heat resistant patching material.   The said cooling board is copper, The manhole obstruction | occlusion wall of the vertical melting furnace of any one of Claims 1-4 characterized by the above-mentioned.   The manhole blocking wall of a vertical melting furnace according to any one of claims 3 to 5, wherein the high thermal conductivity refractory is a refractory excellent in spall resistance.   The manhole closing wall of a vertical melting furnace according to any one of claims 3 to 6, wherein the high thermal conductivity refractory is an alumina brick or a refractory stamp block.   The manhole closing wall of a vertical melting furnace according to any one of claims 3 to 7, wherein the high thermal conductivity refractory has a thermal conductivity of 4 W / m · K or more.   The manhole blocking wall of a vertical melting furnace according to any one of claims 3 to 8, wherein the high thermal conductivity refractory material is a silicon carbide refractory material.

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