Chimney

Abstract

To minimize distortion that may occur in a long cylindrical shape required for an inner wall of an oval-shaped chimney.SOLUTION: An oval-shaped chimney 100 has an inner wall 10, an outer wall 20, and a heat insulating layer 30. The inner wall 10 has a semicircular arc-shaped plate 11 and a flat plate 15. The semicircular arc-shaped plate 11 has a plurality of band plates 13 extending in a spiral direction, and adjacent band plates 13, 13 are joined by a joint mechanism 40 using seams that extend in the spiral direction. The semicircular arc-shaped plate 11 overlaps the inside of a semicircular arc-shaped band-like template 60 to maintain its shape.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an oval-shaped chimney having an insulating layer interposed between an outer wall and an inner wall made of a thin steel plate. [Background technology]

[0002] Chimneys, which discharge exhaust flows such as smoke and exhaust gases sent from an exhaust source to the outside through a flue, are generally shaped like a rectangular tube, a cylinder, an oval, etc. Conventionally, chimneys have been known that have a heat insulating layer between an outer wall and an inner wall made of thin steel plates.

[0003] Prior art 1 (Patent Document 1) describes that in a cylindrical chimney, the inner wall is formed by spirally winding a strip made of thin steel plate, that spirally wound strips made of thin steel plate that are adjacent in the axial direction are joined by seams, and that continuous spirally extending convex ridges are formed on the inner wall.

[0004] Prior art 2 (Patent Document 2) describes an oval chimney formed in the shape of an elongated cylinder, and states that the oval chimney has two semicircular arc wall portions and two flat wall portions of equal width.

[0005] The inner wall of an oval chimney can be formed from a pair of left and right semicircular arc plates in plan view and a pair of front and rear flat plates disposed between the circumferential ends of the semicircular arc plates and connected to the semicircular arc plates. The pair of left and right semicircular arc plates can also be obtained by dividing a cylinder in half radially. In this case, due to the elastic properties of thin steel plates, each of the two semicircular arc plates formed by dividing a cylinder in half radially may always have an inherent stress in the expansion direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Publication No. 3234312 (Figures 1 to 3) [Patent Document 2] Publication No. 3241934 (Figure 5, paragraph 0025) Summary of the Invention [Problem to be solved by the invention]

[0007] However, as described above, if the inner wall made of thin steel plate is formed by joining a semicircular arc-shaped plate and a flat plate, which always have stress in the expansion direction, there is a risk of distortion occurring in the shape required for the inner wall.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a chimney having a structure that can minimize distortion that may occur in the inner wall of an oval chimney and helps to eliminate obstacles that may occur in the manufacturing process of an oval chimney. In particular, the present invention aims to provide a chimney having a structure that is useful when two semicircular arc-shaped plates are manufactured by dividing a cylinder formed by spirally winding a thin steel strip in half in the radial direction. [Means for solving the problem]

[0009] The chimney of the present invention is an oval-shaped chimney with an insulating layer interposed between an outer wall and an inner wall made of thin steel plate, and the inner wall has a pair of left and right semicircular arc-shaped plates in a plan view, and a pair of front and rear flat plates arranged between the circumferential ends of these semicircular arc-shaped plates and connected to the semicircular arc-shaped plates, each of the pair of left and right semicircular arc-shaped plates has a plurality of strip plates extending in a spiral direction stacked in the axial direction of the chimney, and adjacent strip plates are connected to each other by a joining mechanism using seams extending in the spiral direction, and the semicircular arc-shaped plates are overlapped on the inside of the strip-shaped plate that is semicircular arc-shaped in a plan view to maintain their shape.

[0010] In a chimney constructed in this manner, the semicircular plates connected to the flat plate are overlapped on the inside of the band-shaped template that is semicircular in plan view to maintain their shape, so that even if stress in the expanding direction is present in the semicircular plate, the occurrence of distortion caused by that stress is minimized. Furthermore, because the multiple bands stacked in the axial direction of the chimney and extending in a spiral direction are joined together by a joining mechanism that extends in the spiral direction, the shape-maintaining effect of the band-shaped template is likely to extend to the entire semicircular plate.

[0011] In addition, in the manufacturing process of a semicircular arc-shaped plate, when a semicircular arc-shaped plate is obtained by dividing a cylinder in two radially, if two strip-shaped templates that are semicircular arc-shaped in a plan view are overlapped on the outside of the cylinder in a process before dividing it in two, the semicircular arc-shaped plate obtained by dividing it in two will be overlapped on the inside of the strip-shaped templates and will maintain its shape, making it less likely that the resulting semicircular arc-shaped plate will expand, eliminating a problem that can arise in the manufacturing process, namely, the semicircular arc-shaped plate obtained by dividing a cylinder in two will expand and become an obstacle to proceeding with subsequent processes.

[0012] In the present invention, it is possible to adopt a configuration in which the inner wall has a continuous ridge formed by a spiral ridge formed on the inner surface of the pair of left and right semicircular arc-shaped plates in a plan view and extending in a spiral direction, and an inclined ridge formed on the inner surface of the pair of front and rear flat plates, continuing from the spiral ridge, and extending in an inclined direction. This configuration has the advantage that the exhaust flow ascending through the chimney flue tends to flow along the spiral ridge or inclined ridge, resulting in a spiral flow with little exhaust resistance. In addition, the continuous ridge formed by the spiral ridge and inclined ridge also serves to reinforce the inner wall.

[0013] In the present invention, it is desirable that flanges are joined to both circumferential ends of the semicircular arc plate and that the band-shaped template is joined to the flanges, thereby ensuring the shape retention effect of the band-shaped template.

[0014] In the present invention, the semicircular plates and the flat plates may be joined by flange joints or welding. Also, a seam joint is preferably used as the joining mechanism extending in the spiral direction to join the adjacent strips. [Effects of the Invention]

[0015] In the chimney of the present invention, the shape-retaining effect of the band-shaped template, which is semicircular in plan view, minimizes distortion that may occur in the shape required for the inner wall of an oval chimney. Furthermore, when a manufacturing process is adopted in which a semicircular arc-shaped plate is obtained by dividing a cylinder in half radially, by overlapping the band-shaped template on the outside of the cylinder, the shape-retaining effect of the band-shaped template prevents the semicircular arc-shaped plate obtained by dividing the cylinder in half from expanding, thereby eliminating problems that may occur in the manufacturing process. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view of an oval-shaped chimney according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view showing the inner wall of the chimney. [Figure 3] FIG. 10 is an enlarged cross-sectional view showing a joining mechanism using seams. [Figure 4] FIG. 10 is a plan view of a cylinder used to manufacture a semicircular arc plate. [Figure 5] FIG. 2 is a view corresponding to FIG. 2 and showing another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] FIG. 1 is a plan view of an oval-shaped chimney 100 according to an embodiment of the present invention, and FIG. 2 is a schematic perspective view showing an inner wall 10 of the chimney.

[0018] As shown in Figure 1, this chimney 100 has an insulating layer 30 interposed between an outer wall 20 made of a steel plate formed into an oval shape in a plan view and an inner wall 10 made of a thin steel plate also formed into an oval shape in a plan view. The thin steel plate forming the inner wall 10 is made of a stainless steel plate having a thickness of about 0.6 to 1.5 mm, and the internal space of this inner wall 10 forms a flue. The insulating layer 30 uses calcium silicate, which has a small thermal shrinkage rate and excellent insulation properties, heat resistance, and abrasion resistance, as well as rock wool, either alone or in combination with ceramic fiber or the like in the form of a composite.

[0019] As shown in FIG. 1 or 2 , the inner wall 10 includes a pair of left and right semicircular plates 11, 11 in a plan view, and a pair of front and rear flat plates 15, 15 disposed between the circumferential ends of the semicircular plates 11, 11 and connected to the semicircular plates 11, 11. At the connection between the semicircular plates 11 and the flat plates 15, flanges 12, 16 made of L-shaped angles (angle irons) provided on the semicircular plates 11 and the flat plates 15 are connected (flange-connected) with bolts and nuts (not shown). The semicircular plates 11 and the flat plates 15 may be connected by welding instead of the flange connection described here. When using welding, it is possible to provide connecting pieces at the respective ends of the semicircular plates 11 and the flat plates 15 and weld the overlapping portions of the connecting pieces together.

[0020] Each of the left and right semicircular arc plates 11 has a plurality of spirally extending strip plates 13 stacked in the axial direction of the chimney 100, and adjacent strip plates 13, 13 are connected by a joining mechanism 40 using seams that extend in the spiral direction.

[0021] 3 is an enlarged cross-sectional view showing a seam joint, which is an example of the joining mechanism 40. This seam joint joining mechanism 40 is formed between two adjacent strips 13, 13 by slidably engaging an inward folded piece 41 formed on the edge of the upper strip 13 with an outward folded piece 42 formed on the edge of the lower strip 13. This seam joint joining mechanism 40 functions to absorb thermal deformation of the inner wall 10.

[0022] 1 and 2, each of the pair of left and right semicircular plates 11, 11 forming the inner wall 10 has helical ridges 51, 51 formed on its inner surface and extending in a spiral direction, while each of the pair of front and rear flat plates 15 forming the inner wall 10 has inclined ridges 52, 52 formed on its inner surface by press working and extending in an oblique direction. The helical ridges 51 on the semicircular plates 11, 11 and the inclined ridges 52 on the flat plates 15, 15 are arranged so as to be continuous with each other, so that the helical ridges 51 and 52 form a continuous ridge 50 along the entire inner circumference of the inner wall 10. The illustrated example shows a case in which two continuous ridges 50 are formed between adjacent seam-jointed connecting mechanisms 40, 40.

[0023] Next, as shown in Figures 1 and 2, a band-shaped template 60 having a semicircular arc shape in a plan view is provided at a predetermined position in the axial direction of the inner wall 10, or in the illustrated example, at one position in the middle of the axial direction of the inner wall 10. The inner surface of this band-shaped template 60 has the same curvature as the outer surface of the semicircular plate 11, and by overlapping it with the outer surface of the semicircular plate 11 as shown, it helps to prevent deformation of the semicircular plate 11 in the expansion direction. In other words, the semicircular plate 11 is overlapped on the inside of the band-shaped template 60 having a semicircular arc shape in a plan view, thereby maintaining its shape. The band-shaped template 60 is joined to the semicircular plate 11 by welding its end to the flange 12 on the semicircular plate 11 side or by directly welding it to the semicircular plate 11. Therefore, even if stress in the expanding direction is present in the semicircular plate 11, the band-shaped template 60 resists that stress and prevents deformation of the semicircular plate 11 in the expanding direction, preventing distortion of the shape required for the inner wall 10. Furthermore, since the multiple band plates 13 stacked in the axial direction of the chimney 100 and extending in the spiral direction are joined together by the joining mechanism 40 using seams extending in the spiral direction, the shape-retaining effect of the band-shaped template 60 described above extends to the entire semicircular plate 11, preventing distortion of the elongated cylindrical shape required for the inner wall 10. The band-shaped template 60 can also be arranged at multiple locations in the axial direction of the inner wall 10.

[0024] The pair of left and right semicircular arc plates 11, 11 of the inner wall 10 made of the above-mentioned thin steel plate are formed by dividing one cylinder into two in the radial direction.

[0025] FIG. 4 is a plan view of a cylinder 70 used to manufacture the semicircular plates 11, 11. The cylinder 70 is manufactured by simultaneously performing a bending process in which a strip is bent into a spiral shape, a process in which a helical ridge is formed on the strip, and a joining process in which the helically bent strips are joined together by seaming. Therefore, the cylinder 70 is provided with the helical ridge 51 and a seam-joining mechanism 40 (not shown in FIG. 4). The cylinder 70 is provided with four flanges 12, 12, 12, 12 formed of L-shaped angles along its outer axial direction. Specifically, two flanges 12, 12 are provided on the outer axial direction of the cylinder 70, with one outer surface of each L-shaped portion of the two L-shaped angles facing each other. Two more flanges 12, 12, each formed of two similar L-shaped angles, are also provided on the outer axial side of the cylinder 70, sandwiching the central axis of the cylinder 70. Two band-shaped templates 60, 60 that are semicircular in plan view are joined to the four flanges 12, 12, 12, 12.

[0026] The cylinder 70 thus manufactured is cut along the cutting line C shown by the dashed line in Figure 4 and divided into two parts in the radial direction, resulting in the production of a pair of semicircular plates 11, 11, each of which has the helical ridge 51 and seam-jointed joint mechanism 40 shown in Figures 1 and 2, flanges 12, 12 consisting of L-shaped angles provided along the axial direction at both circumferential ends of the semicircular plate 11, and a semicircular band-shaped template 60. In this case, each of the two semicircular plates 11, 11 formed by dividing one cylinder 70 into two parts in the radial direction may have an inherent stress in the expansion direction due to the elastic properties of thin-walled steel plates, but the band-shaped templates 60, 60 resist this stress and prevent the semicircular plate 11 from deforming in the expansion direction. Therefore, the semicircular plates 11, 11 formed by dividing the cylinder 70 into two parts do not deform in the expansion direction. This prevents the deformation of the semicircular plate 11 in the expanding direction from causing any problems in the subsequent manufacturing process of the inner wall 10. Furthermore, the multiple strip plates 13 extending in the spiral direction of the semicircular plate 11 are joined together and integrated by the joining mechanism 40 using seams extending in the spiral direction, so that the shape-retaining effect of the strip-shaped template 60 described above extends to the entire semicircular plate, making the semicircular plates 11, 11 even less susceptible to deformation.

[0027] In this embodiment, the band-shaped templates 60, 60 in each drawing are formed by bending a flat bar to have the same curvature as the outer surface of the semicircular plate 11, but as shown in Figure 5, instead of a flat bar, L-shaped angles may be bent to form the band-shaped templates 60, 60 to have the same curvature as the outer surface of the semicircular plate 11. In this case, the L-shaped angles can be outwardly bent to form the band-shaped templates 60, 60 so that one side of each L-shape follows the periphery of the outer surface of the semicircular plate 11 and the other side forms a flange that projects radially outward from the semicircular plate 11. When the band-shaped templates 60, 60 are formed as L-shaped angles by outward bending in this way, the shape-retaining effect of the flange portion 60a makes the arc-shaped plates 11, 11 even less likely to deform. [Explanation of symbols]

[0028] 10 Inner wall 11 Semicircular arc plate 12,16 flange 13 Obiita 15 Flat plate 20 Exterior Wall 30 Insulation layer 40 Seam Joint Mechanism 50 continuous ridges 60 Strip template 100 Chimney

Claims

1. An oval-shaped chimney with an insulating layer interposed between an outer wall and an inner wall made of thin steel plates, the inner wall has a pair of left and right semicircular arc-shaped plates in a plan view, and a pair of front and rear flat plate-like plates disposed between circumferential ends of the semicircular arc-shaped plates and connected to the semicircular arc-shaped plates, A chimney characterized in that each of the pair of left and right semicircular arc-shaped plate bodies has a plurality of strip plates extending in a spiral direction stacked in the axial direction of the chimney, adjacent strip plates are connected to each other by a joining mechanism using seams extending in the spiral direction, and the semicircular arc-shaped plate bodies are overlapped on the inside of the strip-shaped template that is semicircular arc-shaped in a plan view to maintain their shape.

2. 2. The chimney according to claim 1, wherein the inner wall has a continuous ridge formed by a spiral ridge formed on the inner surface of the pair of left and right semicircular arc-shaped plates in a plan view and extending in a spiral direction, and an inclined ridge formed on the inner surface of the pair of front and rear flat plates, continuing from the spiral ridge, and extending in an inclined direction.

3. 3. A chimney according to claim 1 or 2, wherein flanges are joined along both circumferential ends of said semicircular arc plate, and said band-shaped template is joined to said flanges.

4. 4. The chimney according to claim 3, wherein the semicircular arc plate and the flat plate are joined by flange joining or welding.

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