JP2914185B2 - Water-cooled refractory panels for blast furnace wall repair - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled refractory panel used for repairing a blast furnace wall having both a heat shielding function and a cooling function.

[0002]

2. Description of the Related Art The furnace wall of a blast furnace generally comprises a combination of a cooling board or stave and a refractory brick. But,
The furnace wall at the top of the shaft is in a low temperature condition, and is lined with a chamotte or high alumina brick having a thickness of about 600 to 800 mm in order to prevent overcooling of the furnace body. However, the furnace wall at the upper part of the blast furnace shaft is greatly worn by the falling or contact of raw materials such as ore, and usually wears out to about 200 mm in thickness about 5 to 6 years after burning. The wear of the furnace wall does not progress uniformly, and differs depending on the position in the circumferential direction and the height direction. The worn portion of the blast furnace wall brick has severe irregularities and disrupts the furnace profile, so that the gas flow and the uniform falling of the raw materials are disturbed, and the optimal operation cannot be maintained.

Conventionally, repair of a worn portion of a blast furnace wall brick has been carried out by reducing the size of the blast furnace at the time of calm and spraying an irregular refractory on a damaged portion in the furnace, or applying a pre-fired refractory panel to the damaged portion in the furnace. Attempts have been made to maintain the furnace profile by mounting or by injecting irregular refractories from outside the furnace. However,
In these conventional repairs, the in-furnace profile cannot be maintained for a long period of time due to the limit of durability of the refractory, and the operation has been continued while the repair work is being repeated.

[0004] As another repair method, a water-cooled pipe and a steel frame are combined to form an integrated structure, a refractory having a high thermal conductivity is filled between the pipe and the frame, and one surface is provided. A water-cooled refractory panel for repairing a blast furnace having both a refractory function and a cooling function (Japanese Patent Laid-Open No. 60-2878), a metal block having a cooling function inside Cooler (Japanese Patent Publication No. 60-49834) in which a heat insulating layer is interposed between the metal block of the composite cooler and the refractory block integrated with the refractory block (Japanese Patent Publication No. 60-49834). An abrasion-resistant and spalling-resistant SiC plate, which does not have a holding frame made of steel or the like, is mounted at a distance from the furnace inner surface, and a high-adhesion irregular-shaped refractory is placed in the gap between the plate and the furnace inner surface. The pouring method of filling (JP-4
-99109) and the like.

[0005]

Problems to be Solved by the Invention
In the water-cooled refractory panel disclosed in Japanese Patent Publication No. 78, the back surface of the insulated refractory is held by a cooling pipe support frame and studs, but the insulated refractory is not held by the steel frame surface. Has a weak retention function and suffers spalling due to unloading of the hot blast furnace charge. In addition, cracks occur in insulated refractories due to the difference in thermal expansion with studs,
It falls off and cannot withstand long-term use. Tokiko Sho 60-4
In the composite cooler disclosed in Japanese Patent No. 9834, the refractory block and the metal block are held in an uneven connection, so that the base of the unevenness of the refractory block having a small rigidity is easily cracked by an external impact or a thermal impact, It is easy to cause the refractory block to fall off. In addition, since the combined cooler combines a refractory block and a metal block, it has drawbacks such as a large weight of 3 to 5 Ton and a high cost. Furthermore, the method disclosed in JP-A-4-99109 does not supercool the furnace wall since it is a non-water-cooled type. However, the SiC-based plate used is a single refractory made of steel or the like having no holding frame, has a low rigidity as a furnace wall repairing structure, cracks, and cannot withstand long-term use.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the conventional water-cooled refractory panel, have both a heat-shielding function and a cooling function for the repaired surface, maintain slow cooling, and achieve high durability and long life. Another object of the present invention is to provide a water-cooled refractory panel for repairing a blast furnace wall, which can secure a uniform furnace inner wall profile.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, a two-layer insulated refractory is cast and cast on the working surface side of the steel frame in which the water-cooled pipes are installed to maintain slow cooling of the repaired surface, and achieve high durability and long life. The present inventors have sought to achieve a uniform inner wall profile of the furnace, and have achieved the present invention.

That is, the present invention combines a steel frame filled with an amorphous refractory having high thermal conductivity between a water cooling pipe and a steel frame disposed on the back surface, and an insulated refractory made of the amorphous refractory. In the water-cooled refractory panel for repairing the blast furnace wall, the studs were welded to the steel frame operating surface side, and the low strength was applied to the steel frame surface side.
Degree of heat insulation, low thermal conductivity
High strength furnace inner operating surface, and cast the adiabatic monolithic refractory of high thermal conductivity, that constitutes the heat-insulating refractory layer of 2-layer structure in a water cooled refractory panel for blast furnace wall repair, wherein is there.

Further, the present invention is, among the cross Netsu耐 fire material layer of 2-layer structure of furnace operation surface side of the steel frame, the blast furnace wall, characterized in that adding and mixing the metal fibers to the at least one layer It is a water-cooled refractory panel for repair.

[0010]

According to the present invention, a stud is welded and attached to a steel frame surface side of a water-cooled refractory panel for repairing a blast furnace wall, and a low strength, low strength steel plate is provided on a steel frame surface side.
Heat-conductive insulated refractories are placed inside the furnace inside a steel frame.
High strength running surface, to cast the adiabatic monolithic refractory of high thermal conductivity, by configuring the heat-insulating refractory layer of 2-layer structure, the cross-sectional Netsu耐 fire material layer (the furnace operating surface) high temperature (1000 (~ 1200 ° C)
When used on the inner wall of a furnace, the temperature distribution of the adiabatic refractory layer with high strength and high thermal conductivity on the surface responds quickly to the temperature change, even if the temperature of the furnace changes rapidly due to the fluctuation of the high-temperature gas in the furnace. The thermal stress is also greatly reduced, and the occurrence of layer cracks can be significantly suppressed. Moreover, wear of the cross-sectional Netsu耐 fire material layer of the furnace inner side by loading down the movement of the furnace material is reduced,
Low strength, low thermal conductivity heat insulation irregular shape resistance on the steel frame side
The fire layer makes it possible to substantially reduce heat conduction, prevents overcooling in the furnace, and cuts the steel frame with water-cooled pipes.
Heat load Netsu耐 fire material layer mounting surface side is reduced, to suppress the temperature level (about 500 ° C. or less) capable of maintaining the rigidity of the steel frame to securely hold the cross Netsu耐 fire material layer it can.

In the present invention, the high-thermal-conductivity amorphous refractory filled between the water-cooled pipe and the steel frame includes:
Thermal conductivity λ = 11.6 W / m · K (10 kcal / m ·
h.degree. C.) or more, for example, carbon-based stamp material: BFD
-S10, thermal conductivity λ = 11.6 W / m · K, silicon carbide (λ = 16.3 W / m · K) is poured or stamped and filled. Among the two-layered heat-insulating irregular refractories of the two-layer structure forming the operating surface side in the furnace, for example, a low-strength, low-thermal-conductivity refractory is provided on the steel frame surface side in which I-studs having female threads at the ends are arranged in a staggered manner. After casting a cordierite (λ = 1.1-1.3 W / m · K) amorphous refractory or a high alumina (λ = 1.1 W / m · K) amorphous refractory, On the inner working surface of the furnace where a V stud having a male screw at the tip of the I stud is screwed, a SiC material (λ = 12.8) of a high-strength, high-thermal-conductivity refractory material is provided.
(16.3 W / m · K). Thus, by sufficiently lowering the thermal conductivity of the heat insulating material on the steel frame surface side, it is possible to increase the thermal conductivity of the inner working surface of the furnace to some extent, which is advantageous for thermal shock resistance (hot strength). It is possible to arrange materials (refractory generally has the property that high strength and high thermal conductivity coexist).

In addition, at least one of the two-layered insulated refractories is used .
It is effective to add a metal fiber such as steel wire or steel fiber to the layer to enhance the spalling function. Furthermore, if the structure is not mutually restricted at the boundary of the two-layered insulated refractory, even if the above-mentioned furnace temperature changes rapidly, the heat insulation material on the inner working surface of the furnace will have high thermal conductivity. As a result, the followability of the internal temperature of the heat insulating material with respect to the furnace temperature is improved, so that the temperature difference between the furnace inner surface and the heat insulating material can be reduced, and the tensile stress inside the heat insulating material can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. FIG. 1 is a partial cross-sectional side view of a water-cooled refractory panel (hereinafter referred to as a panel) of the present invention, FIG. 2 is a front view of the panel of the present invention on the operating surface side in a furnace, and FIG. FIG. 4 is a cross-sectional view for explaining how to fix a water-cooled refractory panel according to the present invention. 1 to 4, reference numeral 1 denotes a steel frame that holds a two-layered heat insulating refractory 2, and 3 denotes a staggered arrangement on the working surface side of the steel frame 1 in the furnace and a welded tip. A 50 mm long I-stud having a female thread is a cordierite-type adiabatic refractory made of cordierite as a low-strength, low-thermal-conductivity heat-insulating material constituting a part of the insulated refractory 2. And cast. Reference numeral 5 denotes a V-stud having a height of 30 mm attached to a female screw at the tip of the I-stud 3. Reference numeral 6 denotes a high-strength, high-thermal-conductivity heat-insulating irregular-shaped refractory made of SiC, which constitutes a part of the heat-insulating refractory 2. The thickness of the heat-insulating refractory 2 composed of the heat-insulating irregular refractories 4 and 6 on the inner working surface of the furnace, which is formed by casting the V studs 5 on the heat-insulating irregular refractories 4 with a fogging of 20 mm and a thickness of 50 mm. It is formed to a thickness of 100 mm, sufficiently dried to develop strength, and then used.

Reference numeral 7 denotes a water-cooled pipe integrally fixed to the working surface side of the steel frame 1 in the non-furnace side by welding to form a serpentine pipe. The water-cooled pipe 7 is for the purpose of increasing the range of heat absorption and cooling on the back of the steel frame 1. However, a straight pipe may be provided even if it is not necessarily a serpentine tube. 8 is a horizontal rib, 9 is a vertical rib,
The steel frame 1 is welded to increase the rigidity of the cooling structure. Reference numeral 10 denotes a high-thermal-conductivity irregular-shaped refractory which is poured between the steel frame 1 and the cover plate 11 to increase the cooling effect of the water-cooled pipe 7 or filled and formed by stamping.
Amorphous refractories of 11.6 W / m · K (10 kcal / m · h · ° C.) or more, for example, carbon-based stamp material (BF
DS-10, λ = 11.6 W / m · K). The cover plate 11 is filled with an amorphous refractory 10 having a high thermal conductivity or filled and formed by stamping, and then the outer surface is covered with stud bolts 12 and nuts 13 to form an amorphous refractory having a high thermal conductivity. 10 is protected from damage and falling off. In order to further enhance the holding of the irregular-shaped refractory 10 having a high thermal conductivity, it is preferable to attach a stud to the back surface of the steel frame 1 or the water-cooled pipe 7.

In order to repair a locally worn part of a furnace brick of a blast furnace using the water-cooled refractory panel, as shown in FIG. After being exposed, a mortar leak prevention seal plate 22 is provided around the outer periphery of the steel frame 1 of the panel, and then suspended in the furnace using a suspension piece 23 attached to the panel, and then drawn toward the furnace shell 24 side. A water supply pipe 2 connected to a water cooling pipe 7 at a nozzle flange 25 attached to a furnace body
6. The drainage pipe 27 is penetrated and fixed. A mounting bolt (not shown) for mounting and fixing to the furnace shell 24 can be provided on the panel, but in this embodiment, the refractory and the cooling pipe are integrally cast from cast iron and are large in weight ( 3 ~
6 Ton) Lighter weight (1-2) than conventional stave cooler
(Ton), the panel is attached and fixed to the furnace shell 24 by a water supply pipe 26 and a drain pipe 27. Thereafter, the irregular refractory 28 for sealing is sprayed from the inside of the furnace to the outer peripheral portion of the panel, and at the same time, the unevenness of the furnace inner wall profile is repaired. Further, through the mortar press-fit nozzle 29 provided on the nozzle flange 25, the back of the panel and the furnace body brick 2
The mortar 31 is press-fitted into the wear gap 30 of 1 to repair the blast furnace wall.

The part repaired as described above is furnace-furnaceed by an insulating refractory 2 composed of an insulating refractory 6 having high strength and high thermal conductivity and an insulating refractory 4 having low strength and low thermal conductivity. Since the walls are formed, even if a rapid temperature change occurs due to the unloading movement of the raw material in the furnace and the fluctuation of the high-temperature gas in the furnace, the adiabatic refractory 6 having high strength and high thermal conductivity is excellent.
This prevents breakage due to thermal shock. Further, the insulated amorphous refractory 6 on the inner working surface of the furnace has a good ability to follow the furnace temperature, can reduce the temperature difference with the furnace inner surface, and the tensile stress inside the adiabatic amorphous refractory 6 is greatly reduced. In addition, the occurrence of layered cracks is significantly suppressed. In addition, steel frame 1
The heat load on the mounting surface side of the heat-insulating refractory 2 is heat-shielded and protected by the low-strength, low-thermal-conductivity heat-insulating irregular-shaped refractory 4 that constitutes a part of the heat-insulating refractory 2. The working surface side inside the non-reactor is from the water supply pipe 26 to the water cooling pipe 7
And is cooled by the cooling water discharged from the drain pipe 27 through the irregular-shaped refractory 10 having high thermal conductivity, so that the temperature can be maintained at a temperature level capable of maintaining rigidity, and the insulated refractory 2 is reliably held. It can be used for a long period of time by preventing the heat insulating refractory 2 from peeling and falling off.

In the present invention, the heat-insulating refractory 2 is formed of a two-layer structure of a heat-insulating amorphous refractory 4 having low strength and low thermal conductivity and a heat-insulating amorphous refractory 6 having high strength and high thermal conductivity. Therefore, the optimum combination and selection of the materials and thicknesses of the adiabatic refractories 4 and 6 can be made according to the height position of the panels installed in the furnace and the furnace temperature conditions. In addition, when the heat-insulating irregular refractory 6 on the inner working surface of the furnace is worn out or falls off, the scale can be reduced at the time of the calm and the irregular refractory can be spray-repaired from the inside of the furnace to the portion.

[0018]

As described above, the water-cooled refractory panel of the present invention can be manufactured and mounted according to the damage condition of the blast furnace wall, is efficient, and has a two-layer heat insulating refractory and cooling type. The combination with the support mechanism can have both a heat shielding function and a cooling function, and can realize a longer life of the water-cooled refractory panel. In addition, the water-cooled refractory panel reduces the amount of heat removed from the furnace body, and enables the furnace body to be cooled slowly. The overall heat transfer coefficient of the furnace wall is about 85 kJ / m ^{2
h · ℃ (20kcal / m 2} · h · ℃) or less is desirable. By repairing the damaged part of the furnace wall by the water-cooled refractory panel of the present invention, the overall heat transfer coefficient is:
42 to 55 kJ / m ² · h · ° C (10 to 13 kcal /
m ² · h · ° C.), so that an excellent effect can be exhibited from the viewpoint of furnace wall heat load management. Moreover, this panel is lightweight and has excellent workability for installation on the furnace wall.

[Brief description of the drawings]

FIG. 1 is a partial sectional side view of a water-cooled refractory panel of the present invention.

FIG. 2 is a front view of a panel according to the present invention on a working surface side in a furnace.

FIG. 3 is a partial cross-sectional front view of the panel of the present invention on the side opposite to the operating surface inside the furnace.

FIG. 4 is a cross-sectional view for explaining how to fix the water-cooled refractory panel of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel frame 2 Insulated refractory 3 I stud 4, 6 Insulated irregular refractory 5 V stud 7 Water cooling pipe 8 Horizontal rib 9 Vertical rib 10, 28 Irregular refractory 11 Cover plate 12 Stud bolt 13 Nut 21 Furnace brick Reference Signs List 22 seal plate 23 hanging piece 24 furnace shell 25 nozzle flange 26 water supply pipe 27 drainage pipe 29 mortar press-fit nozzle 30 wear gap 31 mortar

Claims (2)

(57) [Claims] 1. A blast furnace in which a steel frame filled with an amorphous refractory having a high thermal conductivity between a water cooling pipe and a steel frame disposed on a back surface thereof and an insulated refractory made of the amorphous refractory are combined and integrated. For water-cooled refractory panels for furnace wall repair,
Insulation with low strength and low thermal conductivity on the steel frame surface side where the studs are welded and attached to the steel frame operation surface side in the furnace
High-strength amorphous refractories are applied to the inner working surface of the steel frame.
Degrees, and cast the adiabatic monolithic refractory of high thermal conductivity, 2
A water-cooled refractory panel for repairing a blast furnace wall, comprising a heat insulating refractory layer having a layer structure . 2. Among the cross Netsu耐 fire material layer of 2-layer structure of furnace operation surface side of the steel frame, blast furnace according to claim 1, characterized in that adding and mixing the metal fibers to the at least one layer Water-cooled refractory panel for wall repair.