JPH0949014A - Steel pedestal for batch furnace truck - Google Patents

Abstract

(57) [Abstract] [Problem] Excellent mechanical strength, low cost, less cracking from corners of pedestal bricks, excellent spalling resistance for rapid heating and cooling, and flexible for thermal expansion of steel to be treated In addition, it is possible to prevent damage to the contact area with the steel to be treated and excessive displacement of the brick divisions, and efficient reactor air convection saves initial costs, while maintaining a high fuel consumption rate. Provide a cradle for a batch furnace trolley that can be operated. SOLUTION: In a plurality of pedestals 4 to be placed and received on a batch furnace trolley 1 for receiving a heat-treated steel material 5, a rectangular shaped pedestal from a deformed baked brick consisting of a lower rectangular base part and an upper columnar part connecting trapezoidal part connecting them. A vertical wall height of the upper columnar portion is not more than twice the length of the upper surface of the upper columnar portion, and a furnace air convection hole penetrating horizontally in the longitudinal direction of the carriage is formed, For batch furnace trucks where bricks are rounded at all corners, furnace air convection holes are circular, and odd-shaped fired bricks are divided vertically and the bottom surface and vertical division surface are non-fixed free contact parts Steel pedestal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pedestal for heat-treating steel products on a trolley of a trolley for batch heat treatment which is a trolley type batch annealing furnace.

[0002]

2. Description of the Related Art A batch furnace is a furnace in which a box-shaped furnace body is charged with a trolley in which steel materials are loaded to intermittently perform heat treatment. This batch furnace has a structure in which the next carriage is loaded immediately after the carriage is extracted from the furnace body because it is a carriage transportation system using a traverser. Such a trolley for a batch furnace is usually made of refractory bricks, but the steel pedestal is usually made of heat-resistant steel, and the initial cost is enormous.
A large amount of calories are consumed in heating the pedestal of heat-resistant steel, and the fuel consumption rate is inevitably low.

Further, since the pedestal made of heat-resistant steel has a large weight, there is a demerit that only a weight obtained by subtracting the pedestal weight from the allowable load of the dolly can be loaded on the dolly.

In the case of a pedestal made of heat-resistant steel, rapid heating,
Repeated cooling causes thermal distortion, in which case the pedestal must be replaced. However, since the pedestal made of heat-resistant steel is expensive, it cannot be easily replaced, and therefore the material to be treated may be adversely affected such as bending and flaws.

On the other hand, in the conventional brick pedestal, as shown in FIG. 5, the furnace air convection holes 10 on the left and right are angular when viewed in the longitudinal direction (a) of the carriage, and the shape of the side surface (b) thereof. Is higher than the length A of the upper surface of the upper columnar portion 14 and the height B of the vertical wall of the upper columnar portion 14 greatly exceeds 1.2 times. There is a problem that the height C of the trapezoidal portion 15 connected to the lower portion thereof is low, and the weight and impact at the time of loading and unloading the steel material cannot be endured and cracks easily occur.

Further, the conventional brick pedestal cannot withstand the bending load due to the expansion of the steel material, and cracks easily occur from the corners. Further, those having a large capacity for increasing strength cannot withstand rapid heating and rapid cooling, and cracks easily occur due to spalling. Further, the conventional brick pedestal is apt to be damaged at the contact surface with the steel material, and therefore has a very short life.

[0007]

The problem to be solved by the present invention is to solve the above-mentioned various problems of the conventional pedestal. That is, it has excellent mechanical strength, low cost, cracks hardly enter from the corners of the pedestal brick, excellent spalling resistance due to rapid heating and rapid cooling, and can flexibly respond to thermal expansion of the steel material to be treated. , The damage of the contact part with the steel to be treated and the excessive deviation of the divided part of the brick are prevented, the volume and weight are small, and the convection of the furnace air is efficient, so the initial cost is small, and It is to provide a cradle for a batch furnace trolley that can operate at a high fuel consumption rate.

[0008]

Means for Solving the Problems According to the invention of claim 1, a means for solving the above-mentioned problems is to provide a plurality of pedestals for placing and receiving heat-treated steel on a batch furnace trolley. Each pedestal is made of a fired brick of a lateral shape that has a lower rectangular trapezoidal section, an upper columnar section, and a connecting trapezoidal section that connects them. The steel pedestal pedestal for a batch furnace trolley is characterized in that it is 1.2 times or less of the vertical length to form a vertically long trapezoidal part, and a furnace convection hole penetrating horizontally in the longitudinal direction of the dolly is formed in the connection trapezoidal part.

The invention of claim 2 is characterized in that the odd-shaped fired bricks constituting each pedestal are provided with rounded corners, and the furnace air convection holes are circular. A steel pedestal for a batch furnace truck.

According to the third aspect of the present invention, the odd-shaped fired bricks constituting each pedestal have a semicircular concave portion forming a furnace air convection hole on one side along the longitudinal direction of the trolley, and the longitudinal direction of the trolley. 3. A steel pedestal for a batch furnace truck according to claim 1 or 2, wherein the steel pedestal for a batch furnace trolley comprises a set of bricks that are divided into two bricks on the left and right sides with a split surface that is parallel to and vertical.

The invention according to claim 4 is characterized in that the odd-shaped fired bricks constituting each pedestal have a bottom surface and a vertical division surface as non-fixed free contact portions. It is a steel pedestal for a batch furnace truck as described in 1.

The invention of claim 5 is characterized in that the odd-shaped fired bricks constituting each pedestal are covered with a pedestal cover made of heat-resistant steel at the upper part thereof. It is a steel pedestal for a batch furnace trolley by such means.

[0013]

The pedestal of the present invention is made of odd-shaped fired bricks, and each pedestal is made of an odd-shaped fired brick, which is composed of a side surface shape of a lower rectangular base portion, an upper columnar portion, and a connection trapezoid portion connecting them, The vertical wall height of the upper columnar portion is 1.2 times or less the upper surface length of the upper columnar portion to form a vertically long trapezoidal portion having a high height C, and a furnace air convection hole penetrating horizontally in the longitudinal direction of the carriage is provided. Since it is formed in the connection trapezoidal portion, it has excellent mechanical strength and is low in cost, and since the furnace air convection holes penetrating in the horizontal direction are formed in the fired brick, the furnace air can be efficiently used in the furnace. Convection is possible and the initial cost of heating the furnace is low. Since the bricks constituting the pedestal are rounded at all corners and the furnace air convection holes are circular, the occurrence of cracks from the corners and the furnace air convection holes is suppressed. Furthermore, the bricks that make up the pedestal are divided into two bricks on the left and right by a vertical dividing surface parallel to the furnace air convection holes, so the capacity per brick is small, and it is suitable for rapid heating and rapid cooling. On the other hand, since the heat transfer in the brick can be quickly followed, cracks are less likely to occur, and the height of the trapezoidal column connection trapezoidal portion is higher than the height of the upper columnar portion, so it is possible to reach the top of the furnace convection hole. It is thick and, as a result, has excellent spalling resistance. The bricks that make up the pedestal do not have the bottom and vertical division surfaces as free contact parts without being fixed, so they are not fixed to other surfaces and can slide freely according to the thermal expansion of the steel material to be treated. Therefore, it is possible to flexibly cope with the thermal expansion of the steel material to be treated and the brick is not damaged. Furthermore, since the upper part of the brick constituting the pedestal that is the contact surface with the steel to be treated is covered with the heat-resistant steel pedestal cover, damage to the contact portion of the brick with the steel to be treated can be prevented, and, It is possible to prevent the deviation between the left and right bricks on the vertical dividing surfaces from becoming excessive. Since cracks are less likely to occur, it is possible to sufficiently withstand the weight and impact of loading and unloading the steel material to be treated on the pedestal.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view seen from the side, which schematically illustrates a truck type batch annealing furnace according to the present invention. The trolley batch type annealing furnace 1 has a plurality of trolleys 2 for one furnace, and the steel materials 5 to be treated are sequentially loaded on the pedestal 4 of the trolley 2 and charged into the trolley type batch annealing furnace 1. Then, heat treatment such as predetermined annealing is performed. When the heat treatment is completed, the dolly 2 for which the heat treatment is completed is extracted from the dolly-type batch annealing furnace 1, and immediately thereafter, the next steel material 5 to be processed is placed on the pedestal 4 and the dolly 2 for which the heat treatment preparation is completed is completed. It has a structure that can be charged.

In the truck type batch annealing furnace 1, as shown in FIG. 1, a plurality of pedestals 4 are arranged between a plurality of burners 6 arranged in the longitudinal direction of the carriage 2. In FIG. 1, the pedestal 4 has nine 1 rows visible in the foreground and two 1 rows of 9 1 rows that are on the opposite side and cannot be seen in the figure
It is arranged in a trolley type batch type annealing furnace 1. Each pedestal 4 is placed on the pedestal mounting floor 3 with its lower part fitted therein. By the way, each cradle 4 is a free contact portion so that it can move freely without being fixed to the cradle mounting floor 3. A fan 7 is provided above the trolley batch type annealing furnace 1,
A uniform temperature environment is created by measuring convection in the room.

FIG. 2 is a view of the pedestal placement floor 3 and the pedestal 4 when the trolley 2 is viewed from the left side of FIG. 1, and shows only one row on the right side of the pedestal 4 having two rows on the left and right. FIG. 3 is a view of the pedestal placement floor 3 and the pedestal 4 when viewed from the direction perpendicular to the longitudinal direction of the trolley 2. The arrangement state of the pedestal 4 on the pedestal placement floor 3 and the heat-resistant steel pedestal, respectively. The shape of the cover 9 is shown. In this embodiment,
The pedestal 4 covered with one heat-resistant steel pedestal cover 9 is vertically 2
It is formed from two sets of a set composed of two odd-shaped fire bricks 8a and 8b, which are divided and have vertical contact surfaces 12 which are free contact portions which can freely slide. There is. That is, one heat-resistant steel pedestal cover 9 is fitted over the bricks of these two sets. The side wall of the brick on the side of the adjacent two bricks is a semi-circular recess 1
1 are formed, and these semicircular recesses 11 of the adjacent bricks form a circular furnace air convection hole 10.
Its shape is as shown in FIG.
And an upper trapezoidal portion 14 and a trapezoidal portion 15 for connecting between them and having a furnace air convection hole 10 on a side portion. The size of the brick bottom length L is 430 mm and the brick height H is 515 m.
m, divided brick width W / 2 is 225 mm, column top surface length A is 230 mm, and column vertical wall height B is 230 mm, 1.2 A
Satisfying the following, the volume of this brick is 37,000 cm ³ ,
The weight is 86 kg / piece. In contrast, the size of the conventional brick is as shown in FIG. 5, and the brick bottom length L is 4
30mm, brick width W is 500mm, brick height H is 515mm,
The length A of the top surface of the pillar is 230 mm and the volume of this brick is 6
At 5,000 cm ³ , the weight is 150 kg / piece. Since the brick of the present invention having the above size is a divided brick, the volume of the brick is 72,000 cm when corresponding to the conventional brick of FIG.
^{At 3} , the weight corresponds to 172 kg.

The bricks of this pedestal are high-alumina fired bricks, and one trolley 2 is a set of 9 bricks, that is, 2 bricks each consisting of 2 bricks, that is, 36 bricks. Alternatively, the pedestal is formed and placed from bricks in nine rows of nine rows of bricks, that is, 72 bricks in a row composed of two pairs of right and left, each pair consisting of two division bricks. That is, when 36 bricks are used, the size of the brick is twice the width of the brick that uses 72 bricks. This embodiment of Figure 2 consists of 72 split bricks. The brick of the pedestal has a shape in which the corners of all corners except the part of the vertical dividing surface 12 are rounded to prevent the occurrence of cracks due to impact or the like.

The heat-resistant steel pedestal cover 9 is made of high-chromium heat-resistant cast steel, and one trolley 2 is provided with 18 heat-resistant steel pedestal covers 9 in two sets of left and right. .

While the conventional brick has a life of about 6 months and is used for heat treatment at 70 to 80 revolutions, in the embodiment shown in FIG. 2 of the present invention, the brick has a life of about 18 months.
It can be used for heat treatment from 0 to 240 rpm and has about 3 times durability.

[0020]

As described above, the cradle of the present invention is
Each of the pedestals is made of an odd-shaped fired brick, which is composed of an odd-shaped fired brick composed of a lower rectangular trapezoidal part, an upper columnar part, and a connection trapezoidal part that connects them in a lateral shape, and the vertical wall height of the upper pillar part Since a vertical trapezoidal portion having a height C of 1.2 times or less the upper surface length of the upper columnar portion and having a furnace air convection hole penetrating horizontally in the longitudinal direction of the carriage is formed in the connection trapezoidal portion, Excellent strength and low cost. Furthermore, since the pedestal of the present invention forms a furnace air convection hole that penetrates in the horizontal direction, the furnace air can be efficiently convected in the furnace, the heat flow in the furnace is good, and the furnace heating It requires less initial cost.
Furthermore, since the bricks that make up the pedestal are rounded at all corners and the furnace air convection holes are circular,
Generation of cracks from corners of bricks and holes for convection of furnace air is suppressed, and it is resistant to impact and can be used for a long time. Furthermore, the bricks that make up the pedestal are divided into two bricks on the left and right by a vertical dividing surface parallel to the furnace air convection holes, so the capacity per brick is small, and rapid heating and rapid cooling are performed. On the other hand, the heat transfer in the brick can be quickly followed. For this reason, cracks are less likely to occur, and the height of the columnar connection trapezoidal portion is higher than the height of the upper columnar portion, so there is wall thickness up to the top of the furnace convection hole, and as a result, spalling resistance is reduced. Are better. In addition, since the bricks that make up the pedestal are free contact parts without fixing the bottom surface and the vertical dividing surfaces, they are not fixed to other surfaces and can slide freely with the other party. It can flexibly respond to the thermal expansion of steel materials and does not damage bricks. Further, since the upper part of the brick that constitutes the pedestal that is the contact surface with the steel to be treated is covered with the heat-resistant steel pedestal cover, damage to the contact portion with the brick of the steel to be treated can be prevented, and It is possible to prevent the deviation between the left and right bricks on the vertical dividing surfaces from becoming excessive. Since the cradle bricks are less likely to crack, the cradle can withstand the weight and impact of loading and unloading the steel to be treated on the cradle. As described above, the steel cradle for the batch furnace trolley of the present invention has an excellent effect that the conventional cradle does not have.

[Brief description of drawings]

FIG. 1 is a side perspective view schematically illustrating a truck type batch annealing furnace.

FIG. 2 is an exploded front view showing a pedestal viewed from the longitudinal direction of the trolley.

FIG. 3 is a side view showing an exploded view of the pedestal as seen from a direction perpendicular to the longitudinal direction of the carriage.

FIG. 4 is a view showing a shape of a pedestal brick of the present invention, (a) is a view showing a divided brick seen from a longitudinal direction of the dolly, and (b) is a view seen from a direction perpendicular to the longitudinal direction of the dolly. Is.

FIG. 5 is a view showing a shape of a conventional pedestal brick, (a) is a view showing the brick as viewed from the longitudinal direction of the dolly, and (b) is a view seen from a direction perpendicular to the longitudinal direction of the dolly. .

[Explanation of symbols]

 1 trolley batch type annealing furnace 2 trolley 3 pedestal platform 4 pedestal 5 steel to be treated 6 burner 7 fan 8 variant fired brick 8a split variant fired brick 8b split variant fired brick 9 heat-resistant steel pedestal cover 10 furnace convection Hole 11 Semi-circular recess 12 Vertical division surface A Column top surface length B Column vertical wall height H Brick height L Brick bottom length W / 2 Division brick width W Brick width

Claims (5)

[Claims] 1. A plurality of pedestals for placing and receiving a heat-treated steel material on a batch furnace trolley, and from a deformed fired brick having a side shape of a lower rectangular pedestal portion, an upper columnar portion and a connection trapezoidal portion connecting them. For each of the pedestals, the vertical wall height of the upper columnar portion is 1.2 times or less the upper surface length of the upper columnar portion to form a vertically long trapezoidal portion, and for the furnace air convection that penetrates horizontally in the longitudinal direction of the carriage. A steel pedestal for a batch furnace trolley, characterized in that holes are formed in the trapezoidal connection. 2. The steel material for a batch furnace trolley according to claim 1, wherein each of the odd-shaped fired bricks constituting each pedestal has rounded corners and circular furnace convection holes. Cradle. 3. The odd-shaped fired bricks constituting each pedestal have a semicircular concave portion forming a furnace air convection hole on one side surface along the longitudinal direction of the bogie, and are parallel to the longitudinal direction of the bogie. The steel pedestal for a batch furnace trolley according to claim 1 or 2, which is composed of a set of bricks divided into two bricks on the left and right sides in a direction division plane. 4. The batch according to any one of claims 1 to 3, wherein the odd-shaped fired bricks constituting each pedestal have bottom surfaces and vertical division surfaces as non-fixed free contact portions. Steel pedestal for furnace truck. 5. The batch according to any one of claims 1 to 4, wherein the odd-shaped fired bricks constituting each pedestal are covered with a pedestal cover made of heat-resistant steel at the top. Steel pedestal for furnace truck.