JP7761433B2 - hearth lid - Google Patents

Description

The present invention relates to a furnace cover for a coke oven.

A furnace lid for opening and closing the mouth of a coke oven is known. Patent Document 1 describes a coke oven lid in which a furnace lid airtight composite member is attached to the furnace interior side of the lid frame. This furnace lid airtight composite member includes a heat-resistant metal seal plate with a flange member attached around its periphery that abuts against the circumferential surface of the furnace wall near the entrance and exit of the coke carbonization furnace, a metal inner furnace plate attached to the furnace interior side of the seal plate, and a metal slide plate attached to the furnace exterior side of the seal plate that is slidable relative to the lid frame. The inner furnace plate, seal plate, and slide plate are integrated together by multiple bolts.

Utility Model Registration No. 3230420

The inventors have come to the following realization regarding furnace hoods: To ensure the sealing performance of a coke oven hood, it is important to ensure a good degree of contact between the furnace frame surface on the furnace body side and the knife edge of the seal plate on the hood side. However, the temperature inside a coke oven is high, at over 1000°C, and a large thermal load is applied to the hood that abuts the coke oven. The seal plate is deformed by repeated expansion and contraction due to this thermal load. This deformation reduces the seal plate's adhesion and results in insufficient sealing performance.

In the furnace hood described in Patent Document 1, the seal plate, furnace inner plate, and slide plate are integrated with stud bolts, and to prevent deformation such as wrinkles in the seal plate, numerous stud bolts are used 25 to 100 mm from both ends of the slide plate in the width direction. In other words, this furnace hood prevents deformation of the seal plate by increasing the number of stud bolts.

It is desirable to replace seal plates at a specified frequency, and to ensure ease of replacement, it is desirable to reduce the number of embedded bolts used to secure the seal plates. However, with the furnace cover in Patent Document 1, if the number of embedded bolts is reduced to ensure ease of replacement, deformation of the seal plates cannot be suppressed to the desired level.

The present invention was made in consideration of these issues, and one of its objectives is to provide a coke oven hood that can suppress deformation of the seal plate.

In order to solve the above problem, one aspect of the present invention provides a furnace cover that can close the mouth of a coke oven and includes a seal plate with a knife edge portion for contacting the furnace rim of the mouth, and a slide plate that is placed on the outside of the furnace and overlaps the seal plate. The slide plate has a slide plate body and a horizontal rib that protrudes from the slide plate body in the thickness direction and extends in the short direction of the mouth.

In addition, any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, systems, etc., are also valid aspects of the present invention.

The present invention provides a coke oven hood that can suppress deformation of the seal plate.

FIG. 1 is a cross-sectional view showing a schematic horizontal cross section of a furnace cover according to this embodiment. FIG. 2 is a front view showing the slide plate of the furnace cover of FIG. FIG. 3 is a side view of the slide plate of FIG. 4 is a cross-sectional view of the slide plate of FIG. 2 taken along the horizontal plane AA. 5 is a cross-sectional view of the slide plate of FIG. 2 taken along the horizontal line BB.

The present disclosure will be described below based on preferred embodiments with reference to the drawings. In the embodiments and variations, identical or equivalent components and parts will be given the same reference numerals, and duplicate explanations will be omitted where appropriate. Furthermore, the dimensions of the parts in each drawing will be enlarged or reduced as appropriate to facilitate understanding. Furthermore, some parts that are not important for explaining the embodiments will be omitted from the drawings.

In addition, separate components that share something in common are distinguished by prefixing their names with "first," "second," etc., and these are omitted when referring to them collectively. Terms including ordinal numbers such as "first" and "second" are used to describe various components, but these terms are used only to distinguish one component from other components and do not limit the components.

First, an overview of this disclosure will be provided. The sealing performance of a coke oven lid depends on the degree of contact between the furnace frame and the knife edge of the lid's seal plate. However, the temperature inside a coke oven is over 1000°C, and the lid that contacts it is subjected to a large thermal load. As a result, the seal plate deforms due to thermal expansion, deteriorating its sealing performance. Because the seal plate is subject to thermal deformation, it is important to regularly replace the seal plate to maintain the lid's sealing performance.

The furnace cover described in Patent Document 1 is configured to integrate the seal plate, furnace inner plate, and slide plate with stud bolts. By positioning the stud bolts within a range of 25 to 100 mm from both lateral ends of the slide plate, deformation (wrinkling) of the seal plate is suppressed and sealing performance is improved. However, with this configuration, the number of stud bolts is significantly increased, which means replacing the seal plate requires a great deal of labor and makes maintenance difficult. Furthermore, with this configuration, there is a high possibility of gas and tar leaks through the bolt holes of the stud bolts.

The seal plate is sandwiched between the furnace inner plate on the furnace interior side and the slide plate on the atmospheric side. Because the furnace interior side of the furnace cover is exposed to high temperatures and the atmospheric side is cooled by the atmosphere, the temperature difference between the inner and outer surfaces is large, making each plate prone to warping. The inventors have discovered that, from the perspective of suppressing warping of the seal plate, it is effective to suppress warping of the slide plate on the atmospheric side.

The inventors' research has revealed that providing multiple horizontal ribs extending laterally on the slide plate suppresses lateral deformation of the slide plate, thereby suppressing deformation of the seal plate and improving the sealing performance of the furnace hood. This configuration eliminates the need for stud bolts to maintain sealing performance. Since the number of bolt holes can be reduced in accordance with the number of stud bolts, the possibility of gas or tar leakage through the bolt holes is reduced, and good maintainability is achieved. Below, the furnace hood of the present disclosure is described in detail with reference to the embodiments.

[Embodiment]
First, the overall configuration of a furnace hood 10 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a horizontal cross section of the furnace hood 10. FIG. 2 is a front view of a slide plate 2. In this figure, (a) an overall view is shown on the left, and (b) an enlarged view of the upper vertical section is shown on the right. The furnace hood 10 is a structure capable of opening and closing the furnace opening 84 of the coking chamber 7 of a coke oven 100. For ease of explanation, the horizontal left-right direction in a front view of the furnace hood 10 is referred to as the horizontal direction, the vertical up-down direction in a front view of the furnace hood 10 is referred to as the vertical direction, and the front-to-back direction in a front view of the furnace hood 10 is referred to as the thickness direction. In this example, the short side of the furnace opening 84 is the direction along the horizontal direction, and the long side of the furnace opening 84 is the direction along the vertical direction. The horizontal, vertical, and thickness directions are perpendicular to each other. In addition, in the thickness direction, the direction from the outside toward the inside of the furnace is referred to as the furnace inside, and the opposite direction is referred to as the furnace outside. Such directional indications do not limit the position of the furnace cover 10, and the furnace cover 10 can be used in any position.

The furnace cover 10 is a structure that presses against and closes the furnace frame 82 attached to the periphery of the kiln opening 84 of a coke oven 100 constructed using refractory materials 8, such as firebricks or non-refractory materials, thereby airtightly sealing the inside of the coke oven's 100 carbonization chamber 7. In this example, when viewed from the front, the longitudinal direction of the furnace cover 10 or kiln opening 84 is the vertical direction, and the lateral direction is the horizontal direction. The furnace cover 10 mainly includes a furnace cover frame 5, a slide plate 2, a seal plate 1, an inner furnace plate 4, and firebricks 6.

The furnace cover frame 5 is a steel frame member with a frame structure formed by casting. The furnace cover frame 5 is installed approximately parallel to the slide plate 2 on the outside of the furnace. The furnace cover frame 5 is sized to fit the vertically long kiln mouth 84 and is installed so that the kiln mouth 84 can be opened and closed. On the inside of the furnace cover frame 5, in order of thickness, are attached the slide plate 2, seal plate 1, furnace inner plate 4, and refractory bricks 6. The slide plate 2, seal plate 1, furnace inner plate 4, and refractory bricks 6 are sometimes collectively referred to as the "furnace cover polymer."

The slide plate 2 is a steel structure that supports the seal plate 1, furnace inner plate 4, and refractory bricks 6, which are located on the main furnace inner surface. It is desirable for the slide plate 2 to be able to withstand the weight of these supported components and maintain a constant shape without bending or deforming even at high temperatures. The slide plate 2 is attached to the furnace cover frame 5 via pins (not shown) and is supported so that it can slide vertically relative to the furnace cover frame 5. The slide plate 2 extends primarily in the vertical and horizontal directions.

The seal plate 1 has a seal plate body 11 and a knife edge portion 12 for abutting against the furnace frame 82 of the kiln opening 84. The seal plate body 11 is a steel plate-shaped member extending vertically and horizontally. The knife edge portion 12 seals the outer periphery of the furnace lid 10 by abutting against the furnace frame 82. The knife edge portion 12 is a member with a knife edge cross-sectional shape (edge-shaped cross-sectional shape) that abuts against the furnace frame 82. The seal plate body 11 has a vertically elongated rectangular shape in front view, and has dimensions that extend vertically from both the top and bottom of the slide plate 2 and horizontally from both the left and right sides of the slide plate 2. The knife edge portion 12 is joined to the outer periphery of the seal plate body 11 by welding.

The seal plate 1 is placed on the inside of the furnace over the slide plate 2. In other words, the slide plate 2 is placed on the outside of the furnace over the seal plate 1. The seal plate body 11 is supported by the slide plate 2, with its main surface abutting against the main surface of the slide plate 2. The seal plate 1 is sandwiched between the slide plate 2 and the furnace plate 4 in the thickness direction.

The in-furnace plate 4 is a steel plate-shaped member attached to the outside of the furnace of the refractory bricks 6. The in-furnace plate 4 is placed on top of the seal plate 1 on the inside of the furnace. One main surface of the in-furnace plate 4 abuts against the main surface of the seal plate 1, and the other main surface abuts against the refractory bricks 6. The in-furnace plate 4 may be composed of a single plate or multiple plates stacked together. The in-furnace plate 4 may include a heat-resistant packing sheet. The packing sheet may be provided on the abutment surface with the refractory bricks 6 and/or on the abutment surface with the refractory bricks 6. The slide plate 2, seal plate 1, and in-furnace plate 4 are integrated by stud bolts (not shown). As an example, the stud bolts are attached laterally inward by the fastening bolts 62 when the in-furnace plate 4 is viewed from above.

The firebricks 6 are heat-resistant structures that protrude into the furnace interior and provide heat protection for the furnace roof polymer and furnace roof frame 5. The firebricks 6 include a firebrick body 61 and multiple fastening bolts 62 extending in the thickness direction. One end of the fastening bolts 62 is embedded in the furnace exterior surface of the firebrick body 61, and the other end protrudes in the thickness direction toward the furnace exterior. The fastening bolts 62 are arranged at predetermined intervals on the furnace exterior surface of the firebrick body 61. In this example, two rows of fastening bolts 62 are arranged horizontally, spaced apart from each other and arranged vertically at predetermined intervals.

The fastening bolts 62 pass through bolt holes 44 in the in-furnace plate 4, bolt holes 14 in the seal plate 1, and bolt holes 24 in the slide plate 2, and protrude from the surface of the slide plate 2 facing outside the furnace. Bolt holes 44, 14, and 24 pass through in the thickness direction at positions corresponding to the positions of the multiple fastening bolts 62. By tightening nuts 63 on the protruding sides of the fastening bolts 62, the slide plate 2, seal plate 1, and in-furnace plate 4, which are integrated by the embedded bolts, are pressed against and fixed to the refractory brick body 61.

The slide plate 2 will be described with reference to Figures 3, 4, and 5. Figure 3 is a side view of the slide plate 2, corresponding to the enlarged view (b) of Figure 2. Figure 4 is a cross-sectional view of the slide plate 2 taken along the horizontal plane along line A-A in Figure 2. Figure 5 is a cross-sectional view of the slide plate 2 taken along the horizontal plane along line B-B in Figure 2.

The slide plate 2 has a slide plate body 21, horizontal ribs 22, vertical ribs 23, and a slide member 31. The slide plate body 21 is a steel plate-shaped member extending in both the vertical and horizontal directions. When viewed from the front, the slide plate body 21 has a rectangular shape that is longer vertically than horizontally, and is approximately the same size as the outer contour of the furnace cover frame 5 when viewed from the front. The main surface of the slide plate body 21 on the inside of the furnace is placed on top of the seal plate 1 on the outside of the furnace and abuts against the seal plate 1.

As shown in FIG. 2 , a plurality of bolt holes 24 are provided at predetermined intervals in the vertical direction at both lateral ends of the slide plate body 21, through which fastening bolts 62 pass to abut the seal plate 1 against the slide plate 2. In this example, two rows of bolt holes 24 spaced apart vertically are arranged horizontally. In FIG. 2 , to distinguish the bolt holes 24, they are labeled, from top to bottom, as first bolt hole 241, second bolt hole 242, third bolt hole 243, and fourth bolt hole 244. A plurality of stud bolt holes 26, through which stud bolts pass, are provided vertically at predetermined intervals in the slide plate body 21. In this example, two rows of four stud bolt holes 26 arranged vertically are spaced apart horizontally. The stud bolt holes 26 are located laterally inward of the bolt holes 24. The number of stud bolt holes 26 is fewer than the number of bolt holes 24.

In order to suppress deformation of the seal plate 1, it is important to suppress deformation of the slide plate 2. Therefore, the slide plate 2 of this embodiment has horizontal ribs 22 that protrude in the thickness direction from the slide plate main body 21 toward the outside of the furnace and extend laterally. The presence of the horizontal ribs 22 increases the lateral rigidity of the slide plate 2, suppressing deformation of the slide plate 2. As shown in Figure 2, the slide plate main body 21 is provided with multiple horizontal ribs 22 in the vertical direction at predetermined intervals. In this example, the horizontal ribs 22 are steel strip-shaped members extending in the horizontal and thickness directions. In Figures 2 and 3, to distinguish the multiple horizontal ribs 22, they are labeled, from top to bottom, as the first horizontal rib 221, the second horizontal rib 222, the third horizontal rib 223, and the fourth horizontal rib 224.

If the horizontal rib 22 were positioned so as to overlap a bolt hole 24 in the vertical direction, the horizontal rib 22 would interfere, making it difficult to pass the fastening bolt 62 through. Therefore, in the slide plate 2 of this embodiment, the horizontal rib 22 is positioned so that it does not overlap with multiple bolt holes 24 in the vertical direction. In other words, the horizontal rib 22 is positioned between two adjacent bolt holes 24 in the vertical direction. This positioning reduces the possibility of the horizontal rib 22 interfering with the fastening bolt 62.

As shown in FIG. 2(b), the first horizontal rib 221, the second horizontal rib 222, the third horizontal rib 223, and the fourth horizontal rib 224 are positioned in the vertical direction to avoid the first bolt hole 241, the second bolt hole 242, the third bolt hole 243, and the fourth bolt hole 244 and not overlap these bolt holes. Furthermore, the second horizontal rib 222 is positioned approximately midway between the adjacent first bolt hole 241 and the adjacent second bolt hole 242. Furthermore, the third horizontal rib 223 is positioned approximately midway between the adjacent second bolt hole 242 and the adjacent third bolt hole 243. Furthermore, the fourth horizontal rib 224 is positioned approximately midway between the adjacent third bolt hole 243 and the adjacent fourth bolt hole 244. As shown in FIG. 2(a), the other horizontal ribs 22 are positioned in a similar manner.

Increasing the lateral rigidity of the slide plate 2 may change the balance with its vertical rigidity, concentrating distortion due to thermal stress in the vertical direction and increasing warpage in the vertical direction. Therefore, in this embodiment, the slide plate 2 has vertical ribs 23 that protrude in the thickness direction from the slide plate body 21 and extend vertically. The vertical ribs 23 are arranged laterally outward of the horizontal ribs 22. This arrangement improves the balance between lateral and vertical rigidity. In this example, the vertical ribs 23 are steel strip-shaped members that extend in the vertical and thickness directions. The vertical ribs 23 may include a single vertical rib body or multiple vertical rib bodies. In the example shown in Figure 2(a), one vertical rib 23 is arranged on each side of the horizontal rib 22, and each vertical rib 23 is composed of multiple (three in this example) first vertical rib bodies 231, second vertical rib bodies 232, and third vertical rib bodies 233 arranged vertically.

The horizontal ribs 22 may be spaced apart from the vertical ribs 23 with a gap between them, but in the example of Figure 4, the horizontal ribs 22 are continuous with the vertical ribs 23. In this case, deformation due to thermal expansion can be further suppressed. The horizontal ribs 22 may be joined to the vertical ribs 23 by welding or the like, or they may not be joined at all. In the example of Figure 4, the second horizontal rib 222 is joined to the two first vertical rib bodies 231, which are spaced apart in the horizontal direction, by welding between these vertical rib bodies.

As shown in Figure 2, the slide plate main body 21 is provided with multiple slide members 31 that can slide relative to the furnace cover frame 5 provided on the outside of the slide plate 2. In the example of Figure 2(a), two rows of slide members 31 are arranged horizontally, spaced apart, with a predetermined spacing between them in the vertical direction. The slide members 31 are joined to the main surface of the slide plate main body 21 on the outside of the furnace by welding or the like.

In the example shown in Figure 5, the slide member 31 has an angular pipe shape with an opening 312 extending vertically on the outside of the furnace. In other words, the slide member 31 has an angular C-shaped cross section. The slide member 31 surrounds the slide body 51, which is fixed to the extending end of the extension body 52 extending from the furnace cover frame 5 toward the inside of the furnace. In particular, the slide body 51 has a roughly rectangular parallelepiped shape that is flattened in the thickness direction, and the slide member 31 has a rectangular parallelepiped space that can accommodate the slide body 51. The slide member 31 and the slide body 51 have a gap that allows them to slide vertically relative to each other. The extension body 52 passes through the opening 312 and has a shape that allows it to slide vertically within the opening 312. The slide member 31 functions as a rail that guides the slide body 51, and the slide body 51 functions as a runner guided by this rail.

In this example, the extension body 52 has a hollow cylindrical shape extending in the thickness direction. A connecting bolt 53 penetrates the furnace cover frame 5 and the extension body 52 in the thickness direction from outside the furnace and is fastened to the slide body 51. With this configuration, the slide body 51 is supported by the furnace cover frame 5.

As shown in Figures 2 and 5, the horizontal ribs 22 are arranged between a pair of left and right slide members 31 that are spaced apart in the horizontal direction. The horizontal ribs 22 may be arranged apart from the slide members 31, but in the example of Figure 5, the horizontal ribs 22 are continuous with the slide members 31. In this case, deformation due to thermal expansion can be further suppressed. The horizontal ribs 22 may be joined to the slide members 31 by welding or the like, or may not be joined.

As shown in Figures 2 and 5, the vertical ribs 23 are positioned laterally outward of the slide member 31. The vertical ribs 23 may be positioned apart from the slide member 31 with a gap between them, but in this example, they are continuous with the slide member 31. In this case, deformation due to thermal expansion can be further suppressed. The vertical ribs 23 may be joined to the slide member 31 by welding or the like, or may not be joined.

If the protrusion dimension H1 of the horizontal rib 22 from the slide plate main body 21 is too small, the deformation suppression effect will be reduced. If this protrusion dimension H1 is too large, manufacturing costs will be high. Therefore, in this embodiment, the protrusion dimension H1 of the horizontal rib 22 from the slide plate main body 21 is less than the protrusion dimension H3 of the slide member 31 from the slide plate main body 21 and is greater than or equal to the thickness dimension H4 of the slide plate main body 21. Within this range, the deformation suppression effect can be ensured while keeping manufacturing costs down. As an example, when the thickness dimension H4 of the slide plate main body 21 is 16 mm, the protrusion dimension H1 of the horizontal rib 22 can be set to be greater than or equal to 20 mm and less than the protrusion dimension H3 of the slide member 31.

The protruding dimension H2 of the vertical rib 23 from the slide plate body 21 may be substantially the same as the protruding dimension H1 of the horizontal rib 22.

The features of the furnace lid 10 of this embodiment, configured as described above, will now be described. The furnace lid 10 is a furnace lid capable of closing the kiln mouth 84 of a coke oven 100, and includes a seal plate 1 provided with a knife edge portion 12 for abutting against the furnace frame 82 of the kiln mouth 84, and a slide plate 2 positioned on the outside of the furnace of the seal plate 1. The slide plate 2 has a slide plate main body 21 and a horizontal rib 22 that protrudes from the slide plate main body 21 in the thickness direction and extends in the short direction of the kiln mouth 84.

With this configuration, the presence of the horizontal ribs 22 helps to suppress lateral deformation of the slide plate 2, and ultimately suppresses deformation of the seal plate 1. As a result, sealing performance can be improved without significantly increasing the number of stud bolts, allowing for easy maintenance.

The above provides a detailed description of exemplary embodiments of the present invention. All of the above-described embodiments merely illustrate specific examples of how the present invention may be implemented. The content of the embodiments does not limit the technical scope of the present invention, and many design changes, such as changes, additions, and deletions of components, are possible within the scope of the inventive concept defined in the claims. In the above-described embodiments, content for which such design changes are possible is described using notations such as "in the embodiment" or "in the embodiment," but design changes are also permitted for content not otherwise specified. Furthermore, hatching on cross sections in the drawings does not limit the material of the hatched objects.

The following describes the modified examples. In the drawings and descriptions of the modified examples, the same components and parts as those in the embodiment are designated by the same reference numerals. Explanations that overlap with the embodiment will be omitted as appropriate, and the focus will be on the configurations that differ from the embodiment.

(Modification)
In the description of the embodiment, an example has been shown in which the slide member 31 is a rail that guides the slide body 51, but the present invention is not limited to this. The slide member may be configured as a runner that is guided by the slide body.

In the description of the embodiment, an example was shown in which the vertical ribs 23 were positioned laterally outside the sliding member 31, but the present invention is not limited to this. The vertical ribs may also be positioned laterally inside the sliding member.

In the description of the embodiment, the horizontal ribs 22 and vertical ribs 23 are shown as being strip-shaped, but they may also have other shapes other than strip-shaped, such as rod-shaped or pipe-shaped.

In the description of the embodiment, one vertical rib 23 is arranged on each side of the horizontal rib 22, but the present invention is not limited to this. Three or more vertical ribs may be arranged, and the vertical ribs 23 and horizontal ribs 22 may be arranged to intersect with each other in a grid pattern.

In the description of the embodiment, as shown in Figure 2, an example was shown in which the slide plate main body 21, horizontal ribs 22, vertical ribs 23, slide member 31, and bolt holes 24 are each arranged symmetrically, but the present invention is not limited to this. Any of the slide plate main body 21, horizontal ribs 22, vertical ribs 23, slide member 31, and bolt holes 24 may be arranged asymmetrically. Furthermore, the horizontal ribs 22 do not have to be perfectly perpendicular to the vertical ribs 23; a slight inclination is acceptable.

The above-mentioned modifications achieve the same functions and effects as the embodiment.

Any combination of the components and variations of the above-described embodiments is also useful as an embodiment of the present invention. New embodiments resulting from such combinations will have the combined effects of both the combined embodiments and variations.

1 Seal plate, 2 Slide plate, 4 Furnace plate, 5 Furnace cover frame, 6 Refractory brick, 10 Furnace cover, 11 Seal plate body, 12 Knife edge portion, 21 Slide plate body, 22 Horizontal rib, 23 Vertical rib, 24 Bolt hole, 31 Slide member, 61 Refractory brick body, 62 Fastening bolt, 82 Furnace frame, 84 Kiln opening, 100 Coke oven.

Claims (5)

A furnace cover capable of closing the mouth of a coke oven,
A seal plate having a knife edge portion joined to its outer periphery to contact the furnace frame of the kiln mouth;
a slide plate disposed on the outer side of the seal plate;
an in-furnace plate provided on the furnace inner side of the seal plate so as to overlap the seal plate, one main surface of which abuts against the main surface of the seal plate and the other main surface of which abuts against the refractory bricks;
Equipped with
The slide plate has a slide plate body, a horizontal rib protruding from the slide plate body in the thickness direction and extending in the short direction of the kiln opening, and a vertical rib protruding from the slide plate body in the thickness direction and extending in the longitudinal direction of the kiln opening, and arranged laterally outside the horizontal rib.
The slide plate body has a plurality of bolt holes through which bolts for abutting the seal plate against the slide plate are passed, and a plurality of stud bolt holes through which stud bolts for integrating the slide plate, the seal plate, and the furnace inner plate are passed, which are provided at predetermined intervals in the longitudinal direction of the kiln mouth;
At the longitudinal position, the transverse rib is disposed at a position not overlapping with the plurality of bolt holes,
the number of the plurality of stud bolt holes is less than the number of the plurality of bolt holes;
The furnace cover has a dimension in which, when viewed from the front, the seal plate extends vertically from both the top and bottom of the slide plate and extends horizontally from both the left and right sides of the slide plate. The furnace cover of claim 1, wherein the horizontal ribs are continuous with the vertical ribs. The slide plate body is provided with a plurality of slide members that are slidable relative to a furnace cover frame that is overlapped with the slide plate on the furnace outer side,
The furnace cover according to claim 1 or 2 , wherein the horizontal rib is arranged between two of the plurality of slide members that are arranged apart in the short direction of the kiln opening. The furnace cover according to claim 3 , wherein the transverse rib is continuous with the two slide members. A furnace cover as described in claim 3 or 4 , wherein the protruding dimension of the horizontal rib from the slide plate body is equal to or greater than the thickness dimension of the slide plate body and is equal to or less than the protruding dimension of the slide member from the slide plate body.