JP2000256715A - Structure for holding refractory in furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refractory holding structure, with which the refractory for protecting the inner part of a furnace, such as a blast furnace, is difficult to receive large thermal stress and is stably held. SOLUTION: Grating holding ribs are fitted to the inside of a cooling stave 9 as a furnace wall body, and a brick as a rectangular parallelepiped refractory 13 is held in each section of the grating holding ribs. The grating holding ribs are composed of steel plate, and plural plate materials 21, 23, 27, 29 are orthogonally disposed to the inside of the furnace wall body in mutually grate- state. The holding of the grate-state is executed by fitting the notching parts A, B. The holding of the refractory is executed with high heat conductivity mortar or through the mortar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for holding a refractory on an inner wall of a blast furnace or the like.

[0002]

2. Description of the Related Art In a blast furnace of an ironworks, iron ore as a raw material, coke as a heat source, a slag composition material, and the like are charged from the upper portion and layered inside. Then, blowing hot air from the bottom of the tuyere to the interior, of iron ore in the internal Fe ₂ 0 ₃ and FeO
, And iron Fe is obtained as pig iron.

[0003] Since the inside of the furnace wall is exposed to the high temperature of the reduction reaction, the furnace wall body must be protected from damage due to the high temperature by using a refractory such as a brick or providing a cooling facility. In addition, in order for the reduction reaction to proceed efficiently, the high temperature inside the furnace must be maintained, so that heat loss through the furnace wall must be prevented by using a refractory such as a brick.

[0004] As a conventional cooling facility, there is one called a cooling stave. As shown in FIG. 9, the cooling stave 101 divides an inner portion of the furnace wall into a plurality of blocks 103 made of cast iron, and provides a cooling water pipe 105 in each block 103 by casting, and the blocks 103 are adjacent to each other. The inside of the furnace wall is formed, and the pipe 105 of each block 103 communicates with the cooling water to flow cooling water to cool the furnace.

[0005] Inside the cooling stave 101,
There are a plurality of structures for holding bricks as refractories 107. For example, a structure in which a brick as the refractory 107 is cast into cast iron (not shown, see Japanese Utility Model Application Laid-Open No. 63-159197).
No.). In this structure, the bricks are held tightly by cast iron, and the cooling stave 1 serving as the furnace wall body is further provided.
The thick portion of 01 expands greatly due to thermal expansion, and the brick receives large thermal stress, causing cracking or, in extreme cases, the brick falling.

On the other hand, as shown in FIG. 9A, unevenness is formed between the thick portion of the cooling stave 101 and the refractory 107 so that the refractory can be held loosely.
09 is formed, the fitting is performed by the unevenness 109 to hold, and an expansion margin 111 is positively provided at the fitting portion (Japanese Patent Laid-Open No. 57-131981). Also,
As shown in FIG. 9B, a locking projection 113 is formed on the cooling stave 101 side in an obliquely upward direction, and the refractory 107 is formed.
A locking recess 115 is formed obliquely in the upper direction.
3 and a recess 115 to hold the structure (Japanese Patent Application No. 9-368428).

[0007]

However, FIG.
In the structure shown in FIG. 3A, although the gradual holding can be performed, the convex portion of the thick portion of the cooling stave 101 also expands significantly due to thermal expansion (arrow 117 in the drawing), and the brick receives a large thermal stress.

In the structure shown in FIG. 9B, since the structure can be held gently and the locking is performed on the back side of the refractory 107, the influence of thermal expansion is small. However, due to the partial locking of the locking projection 113 and the locking recess 115, the heavy refractory 1
07, it is difficult to maintain stable holding.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and refractories are less susceptible to large thermal stress.
An object of the present invention is to provide a refractory holding structure for a furnace that is stably held.

[0010]

In order to solve the above-mentioned problems, a first aspect of the present invention relates to a structure for holding a refractory on an inner wall of a furnace. A refractory holding structure for a furnace, comprising: a slit; a grid-shaped holding rib press-fitted into the slit; and each section formed by the grid-shaped holding rib and holding a rectangular parallelepiped refractory.

According to a second aspect of the present invention, the grid-like holding ribs are composed of vertical ribs and horizontal ribs made of a metal plate and arranged in a grid at right angles to the inner surface of the furnace wall main body and cross each other.
A notch portion is formed at the intersection, and a lattice shape is maintained by fitting at the notch portion, thereby providing a refractory holding structure for a furnace.

In a third aspect of the present invention, the notch portion is formed at both the vertical rib and the horizontal rib at the intersection, and the notch portions are fitted to each other. Structure.

According to a fourth aspect of the present invention, an upwardly bent locking portion is formed at the tip of the horizontal rib, and a locking recess for locking the locking portion is formed on the lower surface of the refractory. A refractory holding structure for a furnace, characterized in that:

The fifth invention is a refractory holding structure for a furnace, wherein the vertical ribs or the horizontal ribs are used in combination of one or more of a copper plate, a steel plate, and a stainless steel plate. .

According to a sixth aspect of the present invention, the furnace wall body further comprises:
A refractory holding structure for a furnace, comprising a cooling stave, wherein the holding of the refractory is performed through a high heat conductive mortar or mortar.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS.
As shown in FIG. In a blast furnace 1 of an ironworks shown in FIG. 2, iron ore as a raw material, coke as a heat source, slag-making material, and the like are charged from a furnace port 3 at an upper portion, and are layered inside. Then, blowing hot air to the inside from the bottom of the air tuyeres 5, causes a reduction of Fe ₂ 0 ₃ and FeO iron ore internally iron Fe as pig iron, obtained from Dezukuguchi 6.

Since the inside of the furnace wall 7 is exposed to the high temperature of the reduction reaction, the furnace wall body is protected from damage due to the high temperature by using a refractory such as a brick or providing a cooling facility, High temperatures inside the furnace must be maintained for the reaction to proceed efficiently. As shown in FIG. 1, the refractory holding structure of this embodiment is provided with vertical ribs 2 on the inside of a cooling stave 9 as a conventional cooling facility.
This is a structure in which a brick, which is a refractory 13, is held by a grid-like holding rib composed of 1 and a horizontal rib 23. For this brick, for example, a silicon carbide brick can be used.

The cooling stave 9 is, as in the prior art,
The inside portion of the furnace wall 7 is divided into a plurality of blocks 15, each of which is made of cast iron, and a pipe 17 for cooling water.
(See FIGS. 4 and 5). The inside of the furnace wall main body 7 is constituted by adjoining the blocks 15 vertically and horizontally, and the pipe 17 of each block 15 is communicated with the cooling water to cool the furnace.

As shown in FIGS. 1, 3 and 4, each grid-like holding rib 11 is made of a steel plate and is directly attached to the inner peripheral surface of the furnace wall main body by a slit 19. That is, on the inner peripheral surface of the cooling stave 9, slits 19 in the form of vertical and horizontal lattices are formed by machining. The rear end 19A (FIG. 3B) of the slit 19 is processed into a curved surface to prevent concentration of stress due to thermal expansion described later.

The grid-like holding ribs 11 are composed of a plurality of thin plate-shaped vertical ribs 21 made of a steel plate and a plurality of thin plate-shaped horizontal ribs 23 which intersect at right angles in the longitudinal direction. At right angles, they are arranged in a grid. At the intersection, notches A and B are formed in the vertical ribs 21 and the horizontal ribs 23, respectively, and they are fitted deeply with each other to maintain a lattice shape. At this time, spot welding (not shown) or the like may be performed on the main part of the fitting portion.

The ends of the vertical ribs 21 and the horizontal ribs 23 maintained in a lattice shape on the rear side (the side facing the furnace wall main body) are press-fitted into the slits 19. The thickness of the vertical ribs 21 and the horizontal ribs 23 is, for example, about 1 mm in consideration of the expansion coefficient of the refractory 13 and the function as a metal joint as described later. Further, an outer peripheral side plate 27, an upper plate 29, and a lower plate 31 are attached to both side surfaces and upper and lower surfaces of the cooling stave 9 with bolts 33. That is, the outer peripheral side plate 27,
Bolt holes 35 are formed in upper plate 29 and lower plate 31, and correspondingly female screw holes 37 are formed in cooling stave 9. Then, the bolt 33 is screwed into the male screw hole 37 via the bolt hole 35.

Longitudinal ribs 2 constituting lattice-shaped holding ribs 11
1, each section 39 formed by the lateral ribs 23, the outer peripheral side plate 27, the upper plate 29, and the lower plate 31 has a rectangular parallelepiped space,
A rectangular parallelepiped brick as the refractory 13 is held in this space. At this time, a high heat conductive mortar (carbon mortar containing an adhesive) 41 is interposed between the back surface of the refractory 13 and the cooling stave 9, and the mortar 41 is usually provided between the refractory 13 and the grid-like holding rib 11. Mortar 43 intervenes.

(Attaching operation) The operation of attaching the grid-like holding ribs 11 to the cooling stave 9 is performed as follows. That is, as shown in FIG. 1, the lower plate 31 is attached to the cooling stave 9 with the bolt 33. Further, a slit 19 formed on the inner peripheral surface of the cooling stave 9 is provided.
Then, the lateral ribs 23 are press-fitted.

In this state, the lowermost refractory 13 is placed while using the mortars 41 and 43. Next, the lowermost horizontal rib 23 is attached. At this time, the notch B of the lowermost horizontal rib 23 is fitted to the notch A of the vertical rib 21. Then, the second-stage refractory 13 is placed thereon while using the mortars 41 and 43. In this manner, the refractories 13 of all the stages are placed, and thereafter, the outer peripheral side plate 27, the upper plate 29, and the lower plate 31 are fixed with the bolts 33.

(Effects of Embodiment) According to this embodiment, the refractory 13 is indirectly provided via the grid-like holding ribs 11 made of a thin steel plate attached to the cooling stave 9 as a furnace wall main body. Since the brick is held, the refractory does not directly receive the thermal stress due to the thermal expansion of the thick portion of the cooling stave 9 as shown in FIG.
Can be prevented.

Each section 39 of the grid-like holding rib 11
In addition, since the rectangular parallelepiped refractories 13 are held one by one, more stable holding is performed as compared with the conventional structure of FIG. 9B. In particular, the refractory 13 includes the vertical ribs 21, the horizontal ribs 23, the outer peripheral side plate 27, and the upper plate 2 that constitute the lattice-shaped holding rib 11.
9, supported by the lower plate 31, more stable holding is performed.

Further, since the grid-like holding ribs 11 are press-fitted into the slits 19 of the cooling stave 9, they can be mounted more easily than bolts or the like. Furthermore, conventionally, the inner surface of the cooling stave 9
Exposure to the high temperature inside the furnace has always caused cracks due to thermal expansion. That is, the inside of the furnace is at a high temperature, and the coke layer and the ore layer descend at a speed of 5 cm per minute in an alternate state.

The coke layer easily passes gas such as hot air blown therein and has a high temperature. The ore layer, on the contrary, has a low temperature because it is difficult for gas to pass through. For this reason, a periodic temperature change occurs with respect to a certain point inside the furnace. Therefore,
At all times, the inner surface of the cooling stave 9 is repeatedly subjected to thermal expansion, and a state in which there is a difference in thermal expansion between the inner side and the outer side in the thickness direction continues. Therefore, cracks due to thermal expansion are likely to occur.

However, according to this embodiment, the slits 19 are positively provided on the inner surface of the cooling stave 9, so that the large thermal expansion at the inner surface can be absorbed by the slit 19. Therefore, generation of a large stress due to thermal expansion can be suppressed. Even if a small stress is generated, the rear end portion 19A of the slit 19 is processed into a curved surface, so that concentration of the stress can be prevented.

Similarly, the notches A and B (see FIGS. 3 and 1) of the vertical ribs 21 and the horizontal ribs 23 correspond to the vertical ribs 21 and the horizontal ribs 2.
3 can be absorbed, and the generation of large thermal stress can be suppressed. Further, unlike the conventional FIGS. 9A and 9B, the shape of the cooling stave 9 does not need to be complicated, and the manufacturing cost can be reduced.

Further, the grid-like holding ribs 11 include vertical ribs 21, horizontal ribs 23, outer peripheral side plates 27, upper plates 29, and lower plates 31.
The refractory 13 is held one by one in each section 39 formed by. Therefore, these steel plates (21, 23, 27, 29, 31) are located between the refractories 13 that are adjacent to each other.
Is located. Therefore, under the thermal conditions under which the steel sheet softens, the refractory 13 acts as if it were a metal joint and can be prevented from receiving a large thermal stress.

Further, the thermal expansion of the refractory 13 itself increases at the tip of the refractory 13 facing the center of the furnace and having a high temperature. Therefore, as shown in an enlarged manner in FIG.
The tip portion of the refractory 13 becomes thicker in a wedge shape.

Also in this case, under thermal conditions under which the steel sheet softens, it acts as an expansion allowance. Therefore, it is possible to prevent the refractory 13 from receiving a large thermal stress due to the thermal expansion of the refractory 13 itself. Therefore, the durability of the refractory 13 and the durability of the blast furnace itself can be secured. As shown in FIG.
The refractories 13 and metal plates (21, 23, 2)
The tip of 7) is worn out (broken line in the figure) and becomes shorter,
Shortened refractories 13 and metal plates (21, 23, 27, 2)
The tip of (9, 31) becomes wedge-shaped again,
The effect of preventing the refractory 13 from receiving a large thermal stress due to the thermal expansion of the refractory 13 itself continues.

Further, the holding of the refractory 13 is performed through the mortar 41 or the mortar 43 having high thermal conductivity.
These members are firmly fixed by these mortars 41 and 43. Attachment work of the grid-like holding rib 11, refractory 13
Handling at the time of loading the work becomes easy.

Further, since the grid-like holding ribs 11 are cooled from the cooling stave 9, which is the furnace wall main body, through the high heat conductive mortar 41, the strength of the grid-like holding ribs 11 at a portion far from the center of the furnace is prevented. it can. Further, since the inside of the furnace is in a reducing atmosphere, oxidation of the thin steel plate constituting the grid-like holding ribs 11 can be suppressed. Therefore, the refractory 13 can be held firmly.

Further, the grid-like holding ribs 11 of the refractory 13
Is carried out via the mortar 43, so that the mortar 43 absorbs the thermal expansion of the refractory 13 and the grid-like holding ribs 11, which affect each other's thermal stress. In addition, thermal stress due to a difference in thermal expansion between the refractory 13 and the grid-like holding rib 11 is absorbed.

Further, even with the same grid-like support rib 11, the length of the refractory 13 to be held, that is, the thickness of the furnace wall can be freely selected, so that the heat loss can be controlled freely. Further, since the grid-like holding ribs 11 are made of a steel plate, high-precision manufacturing can be easily performed. For example, it can be easily and freely manufactured according to the shape of the curved surface or the flat surface of the cooling stave 9 of any kind.

(Other Embodiments) In the above embodiment, the rear end 19A of the slit 19 (FIG. 3B)
Although formed into a curved surface, in another embodiment, a circular space 19B having a diameter larger than the gap width of the slit 19, that is, a space on the tube (FIG.
By forming (C)), concentration of stress due to thermal expansion can be more positively prevented. Thereby, the thermal expansion of the cooling stave 9 can be absorbed more safely at the slit 19 and cracks can be suppressed.

In the above embodiment, the rear ribs 21 and the horizontal ribs 23 are press-fitted into the slits 19 and fixed to the frictional force. Even with such a simple press-fitting, the entire cooling blast 9 constituting the blast furnace 1 is formed because the entire blast furnace 1 is substantially cylindrical or conical.
Therefore, the plurality of refractories 13 held on the inner peripheral surface of the cooling stave 9 are in an arched state as a whole, and can sufficiently resist the inward force.

However, in another embodiment, in order to obtain a greater frictional force and more sufficiently oppose the inner force, for example, as shown in FIG. Alternatively, it may be driven between the horizontal ribs 23. Further, in another embodiment, for example, FIG.
As shown in (D), the rear ends of the vertical ribs 21 and the horizontal ribs 23 may be formed in a wedge shape.

Further, in the above embodiment, one refractory 13 is held in each section 39, but in other embodiments, a plurality of refractories may be held.
For example, as shown in FIG. 7A, two pieces may be held in each section 39. In FIG. 7, the same parts as those in the above embodiment (FIGS. 1 to 6) are denoted by the same reference numerals. In the above embodiment, the vertical rib 21
Although the intersection of the horizontal rib 23 and the horizontal rib 23 is located linearly, in other embodiments, it may be located in a staggered manner. For example, as shown in FIG.
Is divided into an upper part and a lower part, and the position changes, so that the intersection is located in a staggered manner.

In the above embodiment, the vertical ribs 21 and the horizontal ribs 23 have a planar shape. However, in other embodiments, the locking for securing the refractory 13 more sufficiently. A part may be provided. That is, as shown in FIGS. 7 and 8, for example, a locking portion 47 in which the tip of the lateral rib 23 is bent upward is provided, and a locking concave portion 49 (FIG. 7C) locked by this locking portion is provided. , On the lower surface of the refractory 13.

In the above embodiment, the furnace is the blast furnace 1 of the steel mill, but in other embodiments, another furnace such as a vertical furnace may be used. Further, in the above embodiment, the metal plate constituting the grid-like holding rib 11 is a steel plate, but in other embodiments, a copper plate,
Alternatively, a stainless plate may be used. Further, a combination of a plurality of steel plates, copper plates, and stainless steel plates may be used.

In the above embodiment, the grid-like holding ribs 11 are composed of the vertical ribs 21 located in the vertical direction and the horizontal ribs 23 located in the horizontal direction. The rib material located in the oblique direction may constitute the lattice-shaped holding rib 11.

[0045]

As described above, according to the first, second, third, fourth, fifth or sixth aspect of the present invention, the refractory is provided via the grid-like holding rib attached to the furnace wall main body. Therefore, it is possible to prevent the refractory from directly receiving the thermal stress due to the thermal expansion of the thick portion of the cooling stave as in the related art. In addition, since the rectangular refractory is held in each section of the grid-shaped holding rib, stable holding is achieved as compared with the conventional structure.

Further, since the lattice-shaped holding ribs are press-fitted into the slits of the furnace wall main body, they can be mounted more easily than bolts or the like. Furthermore, since the furnace wall body was exposed to the high temperature inside the furnace, cracks due to thermal expansion had conventionally occurred, but by actively providing slits, thermal expansion could be absorbed at the slits and cracks were suppressed. it can.

According to the second, third, fourth, fifth, or sixth aspect of the present invention, the grid-like holding rib further holds the refractory material by the vertical rib or the horizontal rib made of a metal plate. These metal plates located between the refractories to be fitted are thin members, and the expansion amount due to the thermal expansion of the metal plates is small. Therefore, it is possible to prevent the refractory from receiving a large thermal stress due to the thermal expansion of the grid-like holding ribs. Further, the refractory is supported by the surfaces of the vertical ribs and the horizontal ribs, and more stable holding is performed.

Further, the thermal expansion of the refractory itself increases in a portion of the refractory where the temperature is high facing the center side of the furnace, but at the center side of the furnace, the metal plate located between the refractories softens. The thermal expansion of the refractory itself is absorbed. Therefore, it is possible to prevent the refractory from receiving a large thermal stress due to the thermal expansion of the refractory itself. Further, since the grid-like holding ribs are made of a metal plate, high-precision manufacturing can be easily performed. The fourth, fifth,
Alternatively, according to the sixth aspect, the locking portion of the horizontal rib is locked in the locking recess of the refractory, so that the refractory can be more sufficiently held.

According to the sixth aspect of the present invention, since the holding of the refractory is performed via the high thermal conductive mortar or the mortar, the handling during the work of attaching the grid-like holding ribs and the holding operation of holding the refractory is performed. Becomes easier. Further, since the grid-like holding ribs are cooled from the cooling stave, which is the furnace wall main body, through the high heat conductive mortar, it is possible to prevent a decrease in the strength of the grid-like holding ribs at a portion far from the center of the furnace. Furthermore, since the holding of the refractory was performed through the high thermal conductive mortar or mortar, the thermal expansion of the refractory and the grid-like holding ribs was absorbed by these mortars,
In addition, thermal stress due to a difference in thermal expansion between the refractory and the grid-like holding ribs is absorbed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an operation of attaching a grid-like holding rib constituting a refractory holding structure of a furnace according to one embodiment of the present invention to a cooling stave as a furnace wall main body.

FIG. 2 is an overall schematic view showing a blast furnace which is the furnace of FIG.

FIG. 3A is an exploded perspective view showing an initial state of the mounting operation of FIG. 1; (B) is a perspective view showing a slit of (A). (C) is a perspective view showing a slit according to another embodiment of (A).

FIG. 4 is a perspective view showing a state where the mounting operation of FIG. 1 is completed.

FIG. 5 is an enlarged vertical sectional view showing a main part of FIG.

6A is an enlarged view illustrating the operation and effect of FIG. 5A. FIG. 6B is a view illustrating the aging of FIG. 5A. FIG. 6C and FIG. FIG. 6 is an enlarged view showing the press-fitting structure as another embodiment.

FIG. 7A is a front view of a grid-like holding rib constituting a refractory holding structure of a furnace according to another embodiment of the present invention, as viewed from the inside of the furnace. FIG. 7B is a front view of FIG. Side view (C) is an enlarged view of the main part of (B).

8A is an enlarged perspective view of a main part VIII of FIG. 7A, and FIG. 8B is an exploded partial view of FIG.

9A is a longitudinal sectional view showing a conventional refractory holding structure, and FIG. 9B is a longitudinal sectional view showing another conventional refractory holding structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blast furnace 3 Furnace port 5 Blow tuyere 7 Furnace wall 9 Cooling stave 11 Grid-shaped holding rib 3 Refractory 15 Block 17 Piping 19 Slit 21 Vertical rib 23 Horizontal rib 27 Outer side plate 29 Upper plate 31 Lower plate 35 Bolt hole 37 Female screw Hole 39 Section 41 High thermal conductive mortar 43 Mortar 45 Wedge material 47 Locking portion 49 Locking recess

Claims (6)

[Claims] In a structure for holding a refractory on an inner wall of a furnace, a grid-shaped slit formed on an inner surface of a cast-iron furnace wall body, a grid-shaped holding rib pressed into the slit, and a grid-shaped holding rib. And a compartment for holding the formed rectangular refractory. 2. The grid-like holding ribs are composed of vertical ribs and horizontal ribs made of a metal plate arranged at right angles to the inner surface of the furnace wall main body and intersecting each other in a grid shape. The refractory holding structure for a furnace according to claim 1, wherein a notch portion is formed, and the lattice shape is maintained by fitting in the notch portion. 3. The furnace refractory holder according to claim 2, wherein the notch is formed at both the vertical rib and the horizontal rib at the intersection, and the notches are fitted with each other. Construction. 4. An end portion of the lateral rib is formed with a locking portion bent upward, and a locking recess for locking the locking portion is formed on a lower surface of the refractory. The refractory holding structure for a furnace according to claim 2 or 3. 5. The furnace refractory according to claim 2, wherein the vertical ribs or the horizontal ribs are used in combination of one or more of a copper plate, a steel plate, and a stainless steel plate. Object holding structure. 6. The method according to claim 1, wherein the furnace wall body is constituted by a cooling stave, and the refractory is held through a high thermal conductive mortar or mortar. Or the refractory holding structure of the furnace according to 5.