Fireproof tiles for protecting boiler tubes

Abstract

To provide a fireproof tile for protecting boiler water tubes which prevents cracking, enables easy installation and enhanced adhesive strength, and can be stably installed on boiler water tubes. [Solution] A fireproof tile 1 is integrally molded into a rectangular shape of total width L and total height H, with a first wing portion 2A of width W and height H, a central portion 3, and a second wing portion 2B of width W and height H, and has only three spacers on its back surface and a recess 4 in its center. In the first wing portion 1A, a first spacer 5A is arranged on an imaginary line extending in the height direction from the central portion 3 at a position of width (3 / 4)W. In the second wing portion 2B, a second spacer 5B is arranged on an imaginary line extending in the height direction from the central portion 3 at a position of width (1 / 4)W, and a third spacer 5C is arranged on an imaginary line extending in the height direction from the central portion 3 at a position of width (3 / 4)W. The area S of an imaginary triangle 9 connecting the midpoints of each spacer satisfies {(H / 2)×(LW)} / 2≦S<(L×H) / 2.

Description

[Technical field]

[0001] The present invention relates to a refractory tile for protecting boiler water tubes. [Background technology]

[0002] In facilities such as waste incineration plants that generate power while incinerating waste and power plants that burn fuels such as coal, i.e., combustion plants equipped with boilers, a plurality of boiler water tubes are installed on the furnace wall of the combustion furnace. Generally, the plurality of boiler water tubes are erected vertically and arranged at equal intervals in the horizontal direction, i.e., evenly arranged. Two horizontally adjacent boiler water tubes are connected without any gaps by plate-shaped fins, and these boiler water tubes and fins form a water tube panel.

[0003] In order to protect these boiler water tubes from excessive heat, refractory tiles are sometimes installed on the surface of the boiler water tubes facing the inside of the furnace in the water tube panel. In this case, for example, there is a technique in which hooks are evenly placed on the fins of the water tube panel to mechanically support the refractory tiles (see Patent Document 1). According to this technology, a fireproof joint material such as mortar that acts as an adhesive is applied to the back surface of a rectangular fireproof tile, and the hook is hooked into a depression (hereinafter referred to as a "depression") provided near the center of the back surface of the fireproof tile, and the fireproof tile is pressed against a water tube panel, so that the fireproof tile is fixed onto two adjacent boiler water tubes on both sides of the hook. By repeating this process in sequence, multiple fireproof tiles are installed on the top surfaces of multiple boiler water tubes.

[0004] Here, the fireproof tile in Patent Document 1 is a fireproof tile that protects two horizontally adjacent boiler water tubes with one tile, and has a thin and uniform thickness to uniformly conduct heat from the combustion furnace to the boiler water tubes, and is called a "seagull-shaped" fireproof tile because its horizontal cross-sectional shape resembles a seagull with its wings spread. There are several types of "seagull-shaped" fireproof tiles, including the fireproof tile in Patent Document 2, which has a different structure from Patent Document 1. Conventionally, a large number of spacers have been formed on the back surface of such "Kamome type" fireproof tiles in order to make the fireproof joint material as adhesive applied to the back surface a predetermined thickness. For example, on the back surface of the "Kamome type" fireproof tile in Patent Document 2, nine spacers are aligned for each boiler water tube, that is, a total of 18 spacers are aligned for each fireproof tile. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility model registration No. 3176108 [Patent Document 2] Patent No. 6221186 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a refractory tile having a large number of spacers, cracks may occur starting from the spacers. In addition, when applying the fireproof joint material as an adhesive to the back surface of the fireproof tile, the fewer the number of spacers (protruding objects), the easier the application will be, and the fewer the number of spacers, the stronger the adhesive strength between the fireproof tile and the water pipe panel will be. Therefore, it is conceivable to drastically reduce the number of spacers compared to conventional methods and place three spacers on each "Kamome-type" fireproof tile, which is the minimum number required to ensure stable contact between the tile and the water pipe panel. However, the inventors' trials revealed that even when these three spacers are placed on one "Kamome-type" fireproof tile, cracks still occur starting from the spacer, and the fireproof tile may become loose, making it difficult to install it on a water pipe panel.

[0007] Therefore, an object of the present invention is to provide a "seagull type" refractory tile for protecting boiler water tubes that prevents cracks originating from the spacer, enables easy installation and strengthens adhesive strength, and allows for stable contact with the boiler water tubes, making it easy to install on a water tube panel. [Means for solving the problem]

[0008] The present invention relates to a "Kamome type" refractory tile for protecting boiler water tubes (hereinafter referred to as "refractory tile") which has a first semi-tubular wing portion of width W and height H, a central portion, and a second semi-tubular wing portion of width W and height H connected in sequence in the width direction, and which is integrally molded into a rectangular shape of overall width L and overall height H, and which has a recess formed near the center of the back surface of the central portion for hanging a hook. In particular, the refractory tile of the present invention has a first wing portion and a second wing portion, as viewed from the back side, On one wing, A first spacer is provided, the first spacer being disposed on a virtual line extending in a height direction or in the vicinity of the virtual line at a position (3 / 4)W in a width direction from a center portion, On the other wing, A second spacer is disposed on a virtual line extending in the height direction at a position (1 / 4) W in the width direction from the center portion or in the vicinity of the virtual line; A third spacer is placed on a virtual line extending in the height direction at a position (3 / 4)W in the width direction from the center, or in the vicinity of the virtual line. a first spacer set including two spacers; or A second spacer set including two spacers, a second spacer and a third spacer, arranged at a position (1 / 4)W in the width direction from the center, on a virtual line extending in the height direction, or in the vicinity of the virtual line, spaced apart by a distance of at least (2 / 4)H. The spacer set is either one of the pair. The area S of a virtual triangle formed by connecting the midpoints of the three spacers arranged on one wing and the other wing on a plane in the width direction and height direction is given by: {{(H / 2)×(LW)} / 2}≦S<{(L×H) / 2} These three spacers are arranged so that: Effect of the Invention

[0009] The refractory tile of the present invention has only three spacers in total, that is, a first spacer on one of the two wing portions and a second spacer and a third spacer on the other wing portion. Therefore, compared with conventional fireproof tiles having a large number of spacers, the fireproof joint material can be easily applied to the rear surface of the fireproof tile, and the adhesive strength of the fireproof tile to the water pipe panel can be strengthened. In addition, in the fireproof tile of the present invention, only a first spacer is placed on one wing portion, and the second and third spacers placed on the other wing portion are spaced apart by a distance of about (2 / 4)W in the width direction as in the first spacer set, or by a distance of at least (2 / 4)H as in the second spacer set. Therefore, since the spacers are disposed far apart from each other, it is possible to prevent the occurrence of cracks originating from the spacers. Furthermore, the refractory tiles of the present invention are arranged so that the area S of a virtual triangle formed by connecting the midpoints of the first spacer, the second spacer, and the third spacer satisfies the following relational expression. {{(H / 2)×(LW)} / 2}≦S<{(L×H) / 2} Therefore, when the fireproof tile is installed on the water tube panel, the first spacer arranged on one wing portion and the second and third spacers arranged on the other wing portion can be arranged in a balanced manner so that the fireproof tile can be in stable contact with the boiler water tube without any rattling.

[0010] Therefore, according to the present invention, it is possible to provide a "seagull type" fireproof tile which prevents cracks originating from the spacer, enables easy installation and strengthens adhesive strength, and allows for stable contact with the boiler water tubes, making it easy to install the tile on the water tube panel. [Brief description of the drawings]

[0011] [Figure 1] 1A shows an example of the configuration of a non-interlocking and gull-shaped fireproof tile of the first embodiment, in which (A) is a front view seen from the front side, (B) is a rear view seen from the back side, (C) is a cross-sectional view taken along line AA along the X-axis of (B), and (D) is a cross-sectional view taken along line BB along the Y-axis of (B). [Diagram 2] 1 shows an example of the configuration of an interlocking and gull-type fireproof tile of the second embodiment, in which (A) is a front view seen from the front side, (B) is a rear view seen from the back side, (C) is a cross-sectional view taken along line A'-A' along the X-axis of (B), and (D) is a cross-sectional view taken along line B'-B' along the Y-axis of (B). [Diagram 3] 1(A) is a cross-sectional view in which numbers have been added to FIG. 1(C) and symbols and dotted lines have been added to explain the thickened portion, and FIG. 1(B) is a cross-sectional view of a refractory tile in which no thickened portion is formed. [Figure 4] This is an example (Pattern 1A) of the arrangement of spacers in which the refractory tile has only three spacers. [Diagram 5] This is an example of the arrangement of spacers (Pattern 1B) in which the refractory tile has only three spacers. [Figure 6] This is an example (Pattern 2A) of the arrangement of spacers in which the refractory tile has only three spacers. [Figure 7] This is an example of the arrangement of spacers (Pattern 2B) in which the refractory tile has only three spacers. [Figure 8]This is an example (Pattern 3A) of the arrangement of spacers in which the refractory tile has only three spacers. [Figure 9] This is an example (Pattern 3B) of the arrangement of spacers in which the refractory tile has only three spacers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a gull-shaped fireproof tile which is an embodiment of the present invention and a modified example thereof will be described with reference to Figs. Fig. 1 shows the structure of a refractory tile (non-interlocking type) of a first embodiment, and Fig. 2 shows the structure of a refractory tile (interlocking type) of a second embodiment. Fig. 3 is used to explain the difference between the structure of a refractory tile with a thick wall portion and the structure of a refractory tile without a thick wall portion. 4 to 9 show several examples of the arrangement of each spacer, of which one refractory tile has only three, using the refractory tile of the first embodiment. Here, examples of the arrangement of each spacer are described using the refractory tile of the first embodiment, but the arrangement of each spacer in the refractory tile of the second embodiment is similar, so repeated explanation is omitted. In the following description, first, the basic structures of two main types of refractory tiles, i.e., the non-interlocking type refractory tile of the first embodiment and the interlocking type refractory tile of the second embodiment, of the "Kamome type" refractory tiles will be described, and then, after describing the thickened portions that these two types of refractory tiles may have, examples of the arrangement of each spacer, i.e., the first to third spacers, of which each of these refractory tiles has only three each, will be described.

[0013] For ease of explanation, the drawings will be explained using an orthogonal coordinate system with X, Y, and Z axes as appropriate. Here, the Y axis is arranged vertically, and the X and Z axes are arranged horizontally. The Y axis indicates the up-down direction in which multiple refractory tiles are aligned on the water tube panel, i.e., the height direction. The arrow direction of the Y axis indicates the upward direction among the up-down directions. The X axis indicates the left-right direction in which multiple refractory tiles are aligned on the water tube panel, i.e., the width direction. The Z axis indicates the direction perpendicular to the water tube panel, i.e., the thickness direction of the refractory tile. The arrow direction of the Z axis indicates the direction from the boiler water tube to the refractory tile installed on its upper surface. Here, as an example, the Y-axis direction is described as the vertical direction, but it may be tilted relative to the vertical direction as long as it is along the up-down direction. For example, in some parts of a combustion furnace, the furnace wall may be tilted from the vertical. In that case, the following explanation can be understood by considering the X-axis as a horizontal, while the Y-axis and Z-axis are tilted as an orthogonal coordinate system. In addition, here, when a fireproof tile is installed on a water tube panel, the surface facing the boiler water tube is referred to as the "reverse side," and the surface opposite the reverse side, i.e., the surface facing the inside of the combustion furnace, is referred to as the "front side." The material of the refractory tiles may vary depending on the fuel and furnace temperature of the combustion furnace, but it is preferable to use one whose main raw material is SiC. Each embodiment and each modification are merely illustrative, and are not intended to exclude the application of various modifications or techniques not specifically described. Except for the essential configurations of the present invention, each configuration of each embodiment and each modification can be selected or modified as necessary.

[0014] <Fireproof tile of the first embodiment (non-fitting type)> First, the basic structure of the "non-interlocking type" and "seagull type" refractory tile 1 will be described. The rectangular refractory tile 1 has only one recess 4 formed in the center of its back surface in the X-axis direction and slightly above the center in the Y-axis direction, and is a refractory tile that covers two boiler water tubes. Although a detailed explanation is omitted, when the refractory tile 1 is installed on a water tube panel, the recess 4 is used to hang an L-shaped hook regularly installed on the water tube panel. As shown in Figures 1(B) and 1(D), the recess 4 is formed in the center 3. As shown in Fig. 1(A), the rectangular refractory tile 1 has a rectangular first wing portion 2A covering one boiler water tube on the right side in the width direction of a rectangular central portion 3 provided in the center in the X-axis direction when viewed on the XY plane and on the surface, and has a rectangular second wing portion 2B covering one boiler water tube on the left side in the width direction of the central portion 3. Since the refractory tile 1 is a seagull-shaped refractory tile, the two parts corresponding to the wings of a flying seagull are named the first wing portion 2A and the second wing portion 2B, respectively. The rectangular refractory tile 1 is formed by integrally molding the central portion 3, the first wing portion 2A, and the second wing portion 2B in a connected state. As shown in Fig. 1(C), the first wing portion 2A is semi-tubular in shape, curved along about half of the circumference of a boiler water tube having a circular cross section, as viewed in the XZ plane. Similarly, the second wing portion 2B is semi-tubular in shape, curved along about half of the circumference of a boiler water tube having a circular cross section, as viewed in the XZ plane. The thickness of each of the semi-tubular wing portions 2A, 2B is substantially the same at every point, and is thinner than the thickness of the central portion 3. 1(B), when viewed from the rear side in the XY plane, a first spacer 5A having an elliptical shape elongated in the height direction is integrally molded with the first wing portion 2A, and a second spacer 5B and a third spacer 5C having a similar shape are integrally molded with the second wing portion 2B. That is, one refractory tile 1 includes only three spacers in total.

[0015] In FIG. 1B, the three spacers 5A, 5B, and 5C have the same dimensions, for example, the dimension in the X-axis direction is about 4 mm and the dimension in the Y-axis direction is about 20 mm. In order to make the thickness of the fireproof joint material, which serves as an adhesive for fixing the fireproof tile 1 to the water pipe panel, constant, the dimension protruding from the back surface of the first wing portion 2A or the second wing portion 2B is, for example, about 1.5 mm. However, the dimensions of each of the spacers 5A, 5B, and 5C may be different from each other depending on the design. In addition, each of the spacers 5A, 5B, and 5C is rounded so that there are no corners.

[0016] <Second embodiment of fireproof tile (fitting type)> Next, the basic structure of the "interlocking type" and "seagull type" refractory tile 1' will be described. The refractory tile 1' of the second embodiment differs from the refractory tile 1 of the first embodiment only in that it is an "interlocking" refractory tile. Therefore, the same components as those of the refractory tile 1 will be given the same numbers and descriptions thereof will be omitted. 2(A), when viewed from the surface in the XY plane, the rectangular refractory tile 1' has a first wing portion 2A on the right side in the width direction of a rectangular central portion 3' provided in the center in the X-axis direction, and a second wing portion 2B on the left side in the width direction of the central portion 3'. The rectangular refractory tile 1' is formed by integrally molding the central portion 3', the first wing portion 2A, and the second wing portion 2B in a connected state. As shown in Fig. 2(B), when viewed from the back side in the XY plane, the rectangular refractory tile 1' has only one recess 4 formed in the center in the X-axis direction and slightly above the center in the Y-axis direction. As shown in Fig. 2(B) and Fig. 2(D), the recess 4 is formed in the central portion 3'. Furthermore, as shown in FIG. 2(B), when viewed in the XY plane and on the back side, the central portion 3' is formed with an engaging protrusion 7 that protrudes in a rectangular shape upward from the upper ends of the first wing portion 2A and the second wing portion 2B, and an engaging recess 8 that is recessed in a rectangular shape upward from the lower ends of the first wing portion 2A and the second wing portion 2B and has a dimension that allows the engaging protrusion 7 to be engaged therewith.

[0017] In this way, since the refractory tile 1' has the fitting convex portion 7 and the fitting concave portion 8, a plurality of refractory tiles 1' can be fitted together in the vertical direction and installed on a water pipe panel. Therefore, compared with the case where a non-fitting type refractory tile 1 is installed on a water pipe panel, the fitting type refractory tile 1' installed on a water pipe panel is more resistant to shaking such as an earthquake and can more firmly prevent the refractory tile 1' from peeling off or falling off.

[0018] Here, the structure of the refractory tile 1' having both the fitting convex portion 7 and the fitting concave portion 8 has been described. However, as a modified example of the refractory tile 1', a refractory tile identical to the refractory tile 1' except that it does not have the fitting convex portion 7 and has the fitting concave portion 8, and a refractory tile identical to the refractory tile 1' except that it has the fitting convex portion 7 and does not have the fitting concave portion 8 are prepared, and these three types of fitting type refractory tiles (i.e., the refractory tile 1' of the second embodiment and two types of refractory tiles of the modified examples of the second embodiment) can be combined and installed in the vertical direction on the water pipe panel.

[0019] <Thickened portion that may be provided on the refractory tiles of each embodiment and each modified example> 1 and 2 show a configuration in which the central portion 3 of the refractory tiles 1 and 1' of each embodiment includes a thick portion 6. However, these refractory tiles do not necessarily need to include the thick portion 6. Therefore, the thick portion 6 that the refractory tiles of the respective embodiments and modifications can have will be briefly described with reference to FIG. In addition, when the refractory tiles of the first and second embodiments do not have the thick portion 6, they are treated as a refractory tile of a modified example of the first embodiment or a refractory tile of a modified example of the second embodiment, respectively.

[0020] Fig. 3(A) is a cross-sectional view of Fig. 1(C), which is a cross-sectional view of the refractory tile 1 of the first embodiment taken along line AA, to which numbers, symbols and dotted lines have been added for the purpose of explaining the thick portion 6. Fig. 3(B) is a cross-sectional view of the refractory tile 1 from which the thick portion 6 has been removed, in other words, a cross-sectional view of a refractory tile 1A which is a modified example of the first embodiment and does not include the thick portion 6. Fig. 3(B) corresponds to Fig. 3(A). In addition, although the description will be given using the refractory tile 1 of the first embodiment in Fig. 3, the same applies to the refractory tile 1' of the second embodiment. Therefore, the description of the refractory tile 1' will be omitted by showing a diagram corresponding to Fig. 3.

[0021] First, FIG. 3(B) will be explained, and then FIG. 3(A) will be explained. As shown in Fig. 3(B), the refractory tile 1A has a first wing portion 2A on the +X side of a rectangular central portion 3A provided in the center in the X-axis direction when viewed in the XZ plane, and a second wing portion 2B on the -X side of the central portion 3. In this case, the surface of the central portion 3A corresponds to the surface shown as the central portion 3 in Fig. 1(A) in the refractory tile 1. Also, the back surface of the central portion 3A corresponds to the back surface shown as the central portion 3 in Fig. 1(B) in the refractory tile 1. In FIG. 3B, the substantially rectangular portion between the two dotted lines parallel to the Z axis is the central portion 3A. The dimension from the dotted line indicating the connection between the central portion 3A and the first wing portion 2A to the end position of the first wing portion 2A along the X axis is the width W of the first wing portion 2A. The dimension from the dotted line indicating the connection between the central portion 3A and the second wing portion 2B to the end position of the second wing portion 2B along the X axis is the width W of the second wing portion 2B. The dimension from the end position of the first wing portion 2A to the end position of the second wing portion 2B along the X axis is the total width L of the refractory tile. The overall width L of the refractory tile and the width W of each wing are also used in FIGS.

[0022] As shown in Fig. 3(B), the thicknesses of the first wing portion 2A and the second wing portion 2B are substantially the same at all locations except for the vicinity of the connection portion with the central portion 3A. Therefore, the thickness TA of the refractory tile at the location where the first spacer 5A is formed at the first wing portion 2A, the thickness TB of the refractory tile at the location where the second spacer 5B is formed at the second wing portion 2B, and the thickness TC of the refractory tile at the location where the third spacer 5C is formed at the second wing portion 2B are substantially the same. That is, the relationship TA = TB = TC is substantially established.

[0023] Next, the refractory tile 1 having the thick portion 6 will be described with reference to FIG. The thick portion 6 is shaped like a pad that is formed on the surface of the central portion 3A in Fig. 3(B) in the +Z direction and in contact with the surfaces of the first wing portion 2A and the second wing portion 2B, so as to have a surface on the XY plane. That is, in Fig. 3(A), the portion in which the thickness increases in a fan-like manner from the surface of the central portion 3A in Fig. 3(B) toward the +Z direction, specifically the inverted trapezoidal portion indicated by the two-dot chain line, is the thick portion 6. At this time, the surface of the thick portion 6 formed and connected to the central portion 3A is shown in Fig. 1(A) as the central portion 3. That is, the central portion 3 is formed by integrating the rectangular central portion 3A and the inverted trapezoidal thick portion 6 when viewed in the XZ plane. 3(A), the thickness TB of the refractory tile 1 at the location where the second spacer 5B is formed near the connection between the center portion 3 and the second wing portion 2B is greater than the thickness TA of the refractory tile 1 at the location where the first spacer 5A is formed and the thickness TC of the refractory tile 1 at the location where the third spacer 5C is formed, due to an increment in thickness caused by the thick portion 6. That is, the relationship TB>TA=TC is substantially established.

[0024] In addition, the refractory tile with the thick portion 6 has higher mechanical strength and is less likely to crack than the refractory tile without the thick portion 6. However, the refractory tile without the thick portion 6 is lighter in weight and can conduct heat to the boiler water tubes more uniformly than the refractory tile without the thick portion 6. Therefore, depending on the design specifications, the refractory tile 1 having the thick portion 6 and the refractory tile 1A having no thick portion 6 may be used appropriately.

[0025] <Examples of arrangement of spacers provided in only three refractory tiles in each embodiment and each modified example> Now, examples of the arrangement of the spacers, of which the refractory tile in each of the embodiments and modified examples has only three, will be described below with reference to Figs. First, the premise of each figure will be explained, and then the technical concept behind the arrangement of each spacer will be explained. After that, examples of the arrangement of each spacer based on the technical concept will be sequentially explained. <Prerequisites> For ease of explanation, the arrangement of each spacer will be described using the non-interlocking type refractory tile 1 shown in Fig. 1 in Fig. 4 to Fig. 9. However, the arrangement of each spacer can be applied to the refractory tiles of any of the above-mentioned embodiments or modified examples. All of Figs. 4 to 9 show the rear surface of the refractory tile 1 as viewed in the XY plane. The shape of the non-interlocking refractory tile 1, as viewed on the XY plane, is a rectangle with an overall width L in the X-axis direction and an overall height H in the Y-axis direction. For example, the overall width L can be about 198 mm, and the overall height H can be about 194 mm. As described in the description of FIG. 3, the dimension from the connection point between the central portion 3 and the first wing portion 2A to the endmost position of the first wing portion 2A along the X-axis is defined as the width W of the first wing portion 2A. Also, the dimension from the connection point between the central portion 3 and the second wing portion 2B to the endmost position of the second wing portion 2B along the X-axis is defined as the width W of the second wing portion 2B. For example, the width W may be about 87 mm. The thickness of each wing portion 2A, 2B is formed thin as described above, and may be about 12 mm. In the case of an interlocking type fireproof tile 1', since there is an interlocking protrusion 7, the overall dimension in the Y-axis direction is greater than the total height H. However, the structure of the claim is to be understood in terms of a rectangular portion having a total width L × total height H when viewed in the XY plane. In this embodiment, since the thickness of each of the wing portions 2A and 2B of the refractory tile 1 is thin, the width W is defined as the dimension from the center portion 3 to the outer edge of each of the wing portions 2A and 2B. However, if the refractory tile is thick, the width W may be understood as the inner diameter of each of the semi-tubular wing portions.

[0026] In addition, in order to simplify the explanation, virtual lines are set as follows in Figs. The width W of the first wing portion 2A is divided equally into four, and from the central portion 3 toward the +X-axis direction, a virtual line L1 parallel to the Y-axis is set at a position of (1 / 4)W, a virtual line L2 parallel to the Y-axis is set at a position of (2 / 4)W, and a virtual line L3 parallel to the Y-axis is set at a position of (3 / 4)W. In addition, the width W of the second wing portion 2B is divided equally into four, and from the central portion 3 toward the -X-axis direction, a virtual line L4 parallel to the Y-axis is set at a position of (1 / 4)W, a virtual line L5 parallel to the Y-axis is set at a position of (2 / 4)W, and a virtual line L6 parallel to the Y-axis is set at a position of (3 / 4)W. Furthermore, the total height H of the fireproof tile 1 is equally divided into four, and from the lower ends of the first wing portion 2A and the second wing portion 2B toward the +X-axis direction, a virtual line L7 parallel to the X-axis is set at a position of (1 / 4)H, a virtual line L8 parallel to the X-axis is set at a position of (2 / 4)H, and a virtual line L9 parallel to the X-axis is set at a position of (3 / 4)H.

[0027] <Technical concept behind the placement of each spacer> Each refractory tile 1 is provided with only three spacers in total, namely, a first spacer, a second spacer, and a third spacer, one on one of the first wing portion 2A and the second wing portion 2B and two on the other wing portion. There are two types of spacer groups consisting of a second spacer and a third spacer: a first spacer group in which the second spacer and the third spacer are arranged on or near different imaginary lines parallel to the Y axis, and a second spacer group in which the second spacer and the third spacer are arranged on or near the same imaginary line parallel to the Y axis, separated by a distance of at least (2 / 4)H.

[0028] The inventors have studied several refractory tiles with various arrangements of only three spacers, and have found that even if each half-tubular wing has substantially the same overall thickness, cracks may occur starting from the spacers arranged near the apex of each half-tubular wing, i.e., on or near the imaginary lines L2 and L5. Therefore, spacers are not arranged on or near the imaginary lines L2 and L5.

[0029] In addition, the inventors investigated several fireproof tiles with three spacers arranged in various ways, and found that when the thickness of each wing was as thin as about 12 mm, and multiple spacers were arranged on or near the same imaginary line parallel to the Y-axis, cracks could occur starting from one of the spacers. However, when the thickness of each wing was as thick as about 14 mm, no cracks occurred even in the same arrangement. Therefore, for the two spacers to be arranged on the other wing portion, if the thickness of each wing portion is thin, the first spacer set should be used, and if the thickness is thick, either the first spacer set or the second spacer set should be used. For example, in the case of a refractory tile 1 having a thick portion 6, the thickness of the thick portion 6 is added to the original thickness of the wing portions 2A and 2B near the connection points between the center portion 3 and the wing portions 2A and 2B, which corresponds to the case where the thickness is thick as described above. Therefore, a second spacer set may be used on or near the imaginary line L1 or L4. However, if the two spacers of the second spacer set are placed right next to each other, the fireproof tiles may become loose when they are installed on the water pipe panel, making stable installation difficult. Therefore, there should be a distance of at least (2 / 4)H between the midpoints of the two spacers of the second spacer set, i.e., they should be spaced apart from each other.

[0030] Furthermore, the inventors investigated a number of fireproof tiles with various arrangements of only three spacers and found that the larger the area S of an imaginary triangle 9 formed by connecting the midpoints of the first spacer, the second spacer, and the third spacer on the XY plane is, the more stable the installation of the fireproof tiles on the water pipe panel can be. Therefore, in consideration of the above-mentioned technical concept, the first spacer, the second spacer, and the third spacer are arranged in a well-balanced manner so that the area S of the virtual triangle is larger than the predetermined area. However, since the fireproof tile 1 is a rectangle with a total width L and total height H when viewed on the XY plane, the area S of the imaginary triangle 9 connecting the midpoints of each spacer cannot be at most {(L×H) / 2}, but is less than {(L×H) / 2}. Therefore, the relationship S<{(L×H) / 2} holds. On the other hand, according to the inventors, for example, a fireproof tile in which a first spacer is arranged on the imaginary line L1 of the first wing portion 2A and a second spacer set is arranged on the imaginary line L4 of the second wing portion 2B cannot be stably installed on a water tube panel. However, a fireproof tile in which a first spacer is arranged on the imaginary line L3 of the first wing portion 2A and a second spacer set is arranged on the imaginary line L4 of the second wing portion 2B can be stably installed on a water tube panel if the distance between the midpoints of the second spacer and the third spacer is at least (2 / 4)H. Therefore, the area S in this case is set as the minimum area required from the viewpoint of stable installation. In this case, the area S of the imaginary triangle 9 connecting the midpoints of each spacer is {{(H / 2)×(LW)} / 2}. As a result, the range of area S in which a fireproof tile having only three spacers can be stably installed on a water pipe panel is given by the following relational expression. {{(H / 2)×(LW)} / 2}≦S<{(L×H) / 2}

[0031] <Spacer placement example (Pattern 1)> As an example of the arrangement of three spacers provided on the refractory tile 1, an example of the arrangement of pattern 1 is shown in Fig. 4 and Fig. 5. Fig. 4 shows the arrangement of pattern 1A, and Fig. 5 shows the arrangement of pattern 1B, which is a symmetrical arrangement of pattern 1A. In the arrangement example of pattern 1, the second spacer 5B and the third spacer 5C are an example of an arrangement of the first spacer pair. Now, the arrangement of pattern 1A will be described with reference to FIG. In the arrangement of pattern 1A, the first spacer 5A is positioned on the imaginary line L3 of the first wing portion 2A and above the imaginary line L9, the second spacer 5B is positioned on the imaginary line L4 of the second wing portion 2B and below the imaginary line L7, and the third spacer 5C is positioned on the imaginary line L6 of the second wing portion 2B and above the imaginary line L9. This arrangement satisfies all of the technical concepts described above, and therefore the refractory tile 1 of pattern 1A is a refractory tile that prevents cracks originating from the spacers, allows for easy installation and enhanced adhesive strength, and can be easily installed on a water tube panel by ensuring stable contact with the boiler water tubes. Next, the arrangement of pattern 1B will be described with reference to Fig. 5. In the arrangement of pattern 1B, the first spacer 5A is arranged on the imaginary line L6 of the second wing portion 2B and above the imaginary line L9, the second spacer 5B is arranged on the imaginary line L1 of the first wing portion 2A and below the imaginary line L7, and the third spacer 5C is arranged on the imaginary line L3 of the first wing portion 2A and above the imaginary line L9. That is, the arrangement of pattern 1B is symmetrical to that of pattern 1A. Therefore, the refractory tile 1 of pattern 1B has the same effect as the refractory tile 1 of pattern 1A.

[0032] <Spacer placement example (Pattern 2)> As an example of the arrangement of three spacers provided on the refractory tile 1, an example of the arrangement of pattern 2 is shown in Fig. 6 and Fig. 7. Fig. 6 shows the arrangement of pattern 2A, and Fig. 7 shows the arrangement of pattern 2B, which is a symmetrical arrangement of pattern 2A. In the arrangement example of pattern 2, the second spacer 5B and the third spacer 5C are an example of an arrangement of the first spacer pair. Now, the arrangement of pattern 2A will be described with reference to FIG. In the arrangement of pattern 2A, the first spacer 5A is positioned on the imaginary line L3 of the first wing portion 2A and below the imaginary line L7, the second spacer 5B is positioned on the imaginary line L4 of the second wing portion 2B and above the imaginary line L9, and the third spacer 5C is positioned on the imaginary line L6 of the second wing portion 2B and below the imaginary line L7. Since this arrangement satisfies all of the technical concepts described above, the refractory tile 1 of Pattern 2A can achieve the same effects as the refractory tile 1 of Pattern 1. Next, the arrangement of pattern 2B will be described with reference to Fig. 7. In the arrangement of pattern 2B, the first spacer 5A is arranged on the imaginary line L6 of the second wing portion 2B and below the imaginary line L7, the second spacer 5B is arranged on the imaginary line L1 of the first wing portion 2A and above the imaginary line L9, and the third spacer 5C is arranged on the imaginary line L3 of the first wing portion 2A and below the imaginary line L7. That is, the arrangement of pattern 2B is symmetrical to the arrangement of pattern 2A. Therefore, the refractory tile 1 of pattern 2B has the same effect as the refractory tile 1 of pattern 2A.

[0033] <Spacer placement example (Pattern 3)> As an example of the arrangement of three spacers included in the refractory tile 1, an example of the arrangement of pattern 3 is shown in Fig. 8 and Fig. 9. In the example of the arrangement of pattern 3, the second spacer 5B and the third spacer 5D are an example of the arrangement of the second spacer set. Therefore, it is preferable that the refractory tile of pattern 3 has a thick portion 6. In addition, the third spacer 5D has the same shape as the third spacer 5C in patterns 1 and 2. FIG. 8 shows the layout of pattern 3A, and FIG. 9 shows the layout of pattern 3B, which is a symmetrical layout of pattern 3A. Now, the arrangement of pattern 3A will be described with reference to FIG. In the arrangement of pattern 3A, the first spacer 5A is arranged on the imaginary line L3 of the first wing portion 2A and on the imaginary line L8, the second spacer 5B is arranged on the imaginary line L4 of the second wing portion 2B and below the imaginary line L7, and the third spacer 5D is arranged on the imaginary line L4 of the second wing portion 2B and above the imaginary line L9. Since this arrangement satisfies all of the technical concepts described above, the refractory tiles 1 of Pattern 3A can achieve the same effects as the refractory tiles 1 of Patterns 1 and 2. Next, the arrangement of pattern 3B will be described with reference to Fig. 9. In the arrangement of pattern 3B, the first spacer 5A is arranged on the imaginary line L6 of the second wing portion 2B and on the imaginary line L8, the second spacer 5B is arranged on the imaginary line L1 of the first wing portion 2A and below the imaginary line L7, and the third spacer 5D is arranged on the imaginary line L1 of the first wing portion 2A and above the imaginary line L9. That is, the arrangement of pattern 3B is symmetrical to the arrangement of pattern 3A. Therefore, the refractory tile 1 of pattern 3B has the same effect as the refractory tile 1 of pattern 3A.

[0034] The "Kamome-type" fireproof tiles of the embodiments and modifications of the present invention have been described above. As examples of the arrangement of three spacers that can be applied to the "Kamome-type" fireproof tiles of the embodiments, etc., Pattern 1, Pattern 2, and Pattern 3 have been shown, but the present invention is not limited to these arrangement examples, and can be applied to any "Kamome-type" fireproof tiles as long as the three spacers are arranged so as to satisfy the claims. [Explanation of symbols]

[0035] 1, 1', 1A Kamome-type fireproof tile 2A First wing 2B Second wing 3, 3′, 3A center 4 Recess 5A First Spacer 5B Second spacer 5C Third spacer 5D Third Spacer 6 Thick part 7 Fitting protrusion 8 Fitting recess 9 Virtual Triangle H Overall height L Full width L1 to L9 Virtual lines W Width of one wing TA: Thickness of refractory tile at the location of the first spacer TB: Thickness of refractory tile at the second spacer position TC: Refractory tile thickness at the third spacer position

Claims

1. A refractory tile for protecting boiler water tubes of a Kamome type, comprising a semi-tubular first wing portion having a width W and a height H, a central portion, and a semi-tubular second wing portion having a width W and a height H, which are connected in sequence in the width direction and integrally molded into a rectangular shape having an overall width L and an overall height H, and a recess for hanging a hook is formed near the center of the back surface of the central portion, When viewed from the back side, the first wing portion and the second wing portion are On one wing, a first spacer disposed on a virtual line extending in a height direction or in the vicinity of the virtual line at a position (3 / 4) W in a width direction from the central portion; On the other wing, a second spacer disposed on a virtual line extending in a height direction or in the vicinity of the virtual line at a position (¼) W in a width direction from the central portion; A third spacer is disposed on a virtual line extending in the height direction at a position (3 / 4) W in the width direction from the center portion or in the vicinity of the virtual line. a first spacer set including two spacers, or A second spacer set including two spacers, a second spacer and a third spacer, each of which is disposed at a position (1 / 4) W in the width direction from the central portion, on a virtual line extending in the height direction or in the vicinity of the virtual line, and spaced apart by a distance of at least (2 / 4) H. The spacer set is one of the spacers The area S of a virtual triangle formed by connecting the midpoints of the three spacers arranged on the one wing portion and the other wing portion on a plane in the width direction and the height direction is {{(H / 2)×(L-W)} / 2}≦S<{(L×H) / 2} This is a fireproof tile for protecting boiler water tubes.

2. In the boiler tube protection refractory tile having the first spacer set on the other wing portion, The first spacer is disposed at a height position of (3 / 4)H or more in a height direction from a lower end of the one wing portion upward, the second spacer is disposed at a position (¼)H in a height direction upward from a lower end of the other wing portion or at a position in a height direction less than this position; 2. The refractory tile for protecting a boiler water tube according to claim 1, wherein the third spacer is arranged at a height of (3 / 4) H or higher in the vertical direction from the lower end of the other wing portion upward.

3. In the boiler tube protection refractory tile having the first spacer set on the other wing portion, The first spacer is disposed at a position of (¼)H in a height direction upward from a lower end of the one wing portion, or at a position in a height direction less than that position; The second spacer is disposed at a height position of (3 / 4)H or higher in a height direction from the lower end of the other wing portion upward, 2. The refractory tile for protecting a boiler water tube according to claim 1, wherein the third spacer is arranged at a position (1 / 4)H in the height direction upward from the lower end of the other wing portion or at a position lower than that in the height direction.

4. In the boiler tube protection refractory tile having the second spacer set on the other wing portion, The central portion has a thick portion whose cross-sectional shape is such that the thickness increases in a divergent manner from the back surface to the front surface, The first spacer is disposed at a position of (2 / 4)H in a height direction upward from a lower end of the one wing portion, or at a position in the vicinity thereof; the second spacer is disposed at a position (¼)H in a height direction upward from a lower end of the other wing portion or at a position in a height direction less than this position; 2. The refractory tile for protecting a boiler water tube according to claim 1, wherein the third spacer is arranged at a height position of (3 / 4)H or higher upward from the lower end of the other wing portion.

5. A fitting protrusion is further integrally formed above the central portion and protruding from the upper end thereof, A fitting recess into which the fitting protrusion can be fitted is further integrally formed below the central portion, 5. The boiler water tube protection refractory tile according to claim 1, wherein when two of the boiler water tube protection refractory tiles are arranged in an up-down direction, the fitting convex portion of the boiler water tube protection refractory tile located lower fits into the fitting concave portion of the boiler water tube protection refractory tile located upper.

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