JP6178131B2 - Dismantling method of large storage tank - Google Patents

Description

  The present invention relates to a method for dismantling a large storage tank, and more particularly to a method for dismantling a large storage tank that has a storage tank body that is formed in a spherical shape and that is installed away from the ground.

  As a large storage tank for storing high-pressure gas, it is known that a so-called spherical storage tank having a storage tank body formed in a spherical shape by combining a plurality of metal plate materials is used. When the spherical storage tank is dismantled due to aging, for example, it is desirable to avoid dismantling work at a high place by the worker as much as possible in order to ensure the safety of the worker performing the dismantling work.

  As a technique aimed at avoiding such dismantling work at a high place, the present inventor in Japanese Patent Application No. 6-22083, the storage tank body is directed downward from the center of the ceiling of the storage tank body of the large storage tank. A method for cutting and disassembling a large-scale storage tank has been proposed (Patent Document 1).

JP-A-8-60893

  According to the above-mentioned Patent Document 1, since the cut piece that is cut in a spiral shape is bent downward due to its own weight, the operation of pulling the cut piece downward can be easily performed on the ground with less labor. As a result, dismantling work of workers at high places is avoided as much as possible.

  However, when dismantling large storage tanks, such as spherical storage tanks, the safety of dismantling work by workers on the ground and the safety that does not affect the housing, etc. existing in the vicinity where the large storage tanks are located. It is required to ensure.

  This invention is made | formed in view of the said subject, The objective is to provide the dismantling method of the large sized tank which can ensure the safety | security of dismantling work favorably.

A method for disassembling a large-sized storage tank according to the invention described in claim 1 for solving the above-mentioned problem has a storage tank body formed in a spherical shape, and the storage tank of the large-scale storage tank installed away from the ground. In the dismantling method of the large storage tank in which the bottom of the main body is disassembled, the bottom side of the storage tank main body is cut except for a part, and the cutting portion is bent downward to be grounded to the ground, and the grounding is cut to the ground. It is characterized by disassembling sequentially by cutting the cut portion into a plurality of plate materials in a state where the portion is grounded.

  According to this configuration, the cut part that has been cut with a part left is grounded and supported by the ground, while the remaining part is supported by the storage tank body, and the cut part is between the ground and the storage tank body. It is supported at two points on the tank body.

  Therefore, the cut portion can be disassembled in a state where the bottom cut portion formed on the spherical surface is stably supported. Thereby, the dismantling work of the worker at a high place is avoided as much as possible, and the safety of the dismantling work of the large storage tank by the worker is ensured.

  A method for disassembling a large-sized storage tank according to the invention described in claim 2 for solving the above-mentioned problem has a storage tank body formed in a spherical shape, and the storage tank of the large-scale storage tank installed away from the ground. In the dismantling method of the large storage tank that spirally cuts the main body downward from the upper part of the storage tank main body, the cutting surface is close to the vertical direction in the cutting below the predetermined range from the upper part of the storage tank main body downward. It is characterized by having an inclination.

  According to this configuration, since the cutting below the predetermined range from the upper part of the storage tank main body to the lower side is executed so that the cutting surface has an inclination close to the vertical direction, the cut portion passes through the cutting surface. Descend toward the inside of the storage tank body. Therefore, the cut portion does not diffuse toward the outside of the storage tank body, and does not affect a house or the like existing around the large storage tank.

  The method for disassembling a large-sized storage tank according to the invention described in claim 3 for solving the above-mentioned problem has the storage tank body formed in a spherical shape, and the storage tank of the large-scale storage tank installed away from the ground. In the dismantling method of the large storage tank that cuts the main body spirally from above or below in the installed state of the storage tank body toward the equator line, the cutting gradually increases the cutting interval of the storage tank body as it moves to the equator line. It is characterized by being performed so as to narrow.

  According to this configuration, by gradually narrowing the cutting interval as moving to the equator line, the compressive stress acting on the storage tank body by being formed into a spherical shape was cut when released by cutting. The reaction force of the compressive stress acting on the portion can be suppressed. Therefore, the cut portion does not diffuse toward the outside of the storage tank main body, and does not affect a house or the like existing around the large storage tank.

  A method for disassembling a large-sized storage tank according to the invention described in claim 4 for solving the above-mentioned problem has a storage tank body formed in a spherical shape, and the storage tank of the large-sized storage tank installed away from the ground. In the dismantling method of the large storage tank for disassembling the main body, the bottom part side of the storage tank main body is cut leaving a part, bent the cutting part downward and grounded to the ground, the cutting part grounded to the ground A bottom part dismantling step that sequentially disassembles in a grounded state; and a spiral cutting step that spirally cuts from above or below the storage tank body toward the equator line after the bottom part disassembling step, The cutting in the shape cutting step performs cutting toward the equator line below a predetermined range from the upper part of the storage tank body downward so that the cut surface has an inclination close to the vertical direction, and below the storage tank body Upward from The bought cutting, for cutting intervals according to the process proceeds to the equator line so as to narrow gradually, characterized in that.

  According to this configuration, since the cut portion on the bottom side of the storage tank body is disassembled on the ground in a state supported by the ground and the storage tank body, and the storage tank body is cut in a spiral shape, Dismantling work is avoided as much as possible, ensuring the safety of dismantling work of large storage tanks by workers.

  When the upper part of the storage tank main body is cut in a spiral shape, cutting below the predetermined range from the upper part of the storage tank main body downward is performed so that the cutting surface has an inclination close to the vertical direction. The portion thus formed descends toward the inside of the storage tank body through the cut surface.

  On the other hand, when the lower part of the storage tank body is cut in a spiral shape, the compressive stress acting on the storage tank body by being formed into a spherical shape by gradually narrowing the cutting interval as it moves to the equator line is cut. The reaction force of the compressive stress acting on the cut portion can be suppressed when released by.

  Accordingly, the cut pieces are not diffused outward, so that there is no influence on a house or the like existing around the large storage tank.

  According to the present invention, the dismantling work of the worker at a high place during the dismantling work of the large storage tank is avoided as much as possible, and the safety of the dismantling work of the large storage tank by the worker is ensured. There is no effect on the houses existing in the vicinity, and the safety of the surrounding houses is ensured.

It is a figure explaining the outline of the dismantling method of the large sized storage tank concerning an embodiment of the invention, and Drawing 1 (a)-(e) is a figure showing the process of dismantling. Similarly, it is a figure explaining the outline of the bottom part dismantling process which concerns on this Embodiment. Similarly, it is a conceptual diagram for conceptually explaining the upper cutting step according to the present embodiment. Similarly, it is a figure explaining the outline of the spiral cutting process which concerns on this Embodiment. Similarly, it is a schematic sectional view of a cutting position in a spiral cutting process according to the present embodiment. Similarly, it is a figure explaining the outline of the tank disassembled by the disassembly method of this Embodiment.

  Next, an embodiment of the present invention will be described with reference to FIGS.

  Prior to the description of the dismantling method for the large storage tank according to the present embodiment, an outline of the spherical storage tank to be disassembled will be described with reference to FIG.

  As shown in the drawing, a tank 10 that is a spherical storage tank includes a tank body 20 and a leg 30 that supports the tank body 20 as main components.

  The tank body 20 is formed in a substantially spherical shape by combining a plurality of metal plate materials. In this tank body 20, an intersection line between a plane perpendicular to the polar axis L passing through the center point O in the vertical direction indicated by the arrow P and passing through the center point O of the spherical tank body 20 and the surface of the tank body 20 is Equatorial line B is set.

  A belt portion 26 having an upper edge 26 a and a lower edge 26 b extending along the equator line B and having a predetermined width between the upper edge 26 a and the lower edge 26 b is set in the tank body 20. .

  With reference to the equator line B, the upper part is set as the upper hemisphere 22, the lower part is set as the lower hemisphere 24, the polar axis L is set as the upper pole N, and the point passing through the upper hemisphere 22 is set. A point passing through the lower hemisphere 24 is set as the lower pole S.

  The upper region of the tank body 20 around the upper pole N is set as the ceiling portion 22A, and the lower region of the tank body 20 around the lower pole S is set as the bottom portion 24A.

  The tank body 20 is supported by a leg portion 30 including a plurality of leg body bodies 32 and braces 34 installed crossing between the leg body bodies 32 so that the tank body 20 is separated from the ground G. A tank 10 is erected. Such a tank 10 is mainly used for the purpose of storing high-pressure gas in the tank body 20.

  Next, the outline of the dismantling method of the large-sized storage tank concerning this Embodiment is demonstrated. FIG. 1 is a diagram for explaining an outline of a dismantling method according to the present embodiment, and shows a disassembling process in FIGS. 1 (a) to 1 (e), and FIG. 2 is a diagram for explaining an outline of a bottom part disassembling process. It is. In FIGS. 1A to 1E, the leg portion 30 is partially omitted to improve the visibility of the drawing.

  In the disassembling method according to the present embodiment, first, the bottom 24A of the tank body 20 of the tank 10 is disassembled (bottom disassembling step).

  In this bottom disassembly process, the bottom 24A side of the tank body 20 is cut and bent while leaving a part as shown in FIG. Specifically, the bottom 24A side of the tank 10 is cut along the latitude line x by a burner cutting machine 40, which is a cutting tool in the present embodiment, and is cut so as to leave a part along the latitude line x.

  By cutting the bottom 24A side of the tank body 20 so as to leave a part, as shown in FIG. 1B and FIG. 2, the cut portion 25A which is the cut bottom 24A side is lowered by its own weight. Therefore, the cut portion 25A is grounded to the ground G as it is.

  On the other hand, at the both ends of the remaining portion 25B, which is the remaining portion on the bottom 24A side, a notch 25a is formed by cutting away in an inward direction toward the inside of the remaining portion 25B. By forming the cutout portion 25a, the stress acting on both ends of the remaining portion 25B can be dispersed by the lowering of the cut portion 25A by its own weight, and the unexpected breakage of the remaining portion 25B can be suppressed.

  While the cut portion 25A thus cut is grounded to the ground G and supported by the ground G, the cut portion 25A is supported between the ground G and the tank main body 20 by being supported by the tank body 20 via the remaining portion 25B. In between, it is supported at two points, the ground G and the tank body 20.

  Therefore, in the installed state, the cut portion 25A can be disassembled while the cut portion 25A on the bottom 24A side having a spherical surface facing the ground G is stably supported. Specifically, the cutting portion 25A is disassembled by running the burner fusing machine 40 along a welding line 25b that joins a plurality of metal plates, and sequentially cutting the cut portions into a plurality of metal plates. And then dismantle.

  In this way, the bottom 24 </ b> A side of the tank body 20 is cut off, whereby an opening 25 </ b> C is formed in the tank body 20.

  After this bottom part disassembly process, the process proceeds to a spiral cutting process. In the present embodiment, the spiral cutting step includes an upper cutting step for cutting the upper hemisphere 22 of the tank body 20 and a lower cutting step for cutting the lower hemisphere 24 of the tank body 20 cut off at the bottom 24A side.

  In the upper cutting process, as shown in FIG. 1 (c), the upper hemisphere 22 of the tank body 20 is sequentially cut in a spiral form from the ceiling portion 22A, which is the upper portion of the tank body 20, toward the equator line B, which is below it. To do.

  FIG. 3 is a conceptual diagram for conceptually explaining the upper cutting step according to the present embodiment, and FIG. 4 is a diagram for explaining an outline of the spiral cutting step. As shown in FIG. 3, in the upper cutting process of the present embodiment, the cut surface of the tank body 20 cuts on the tangent lines T <b> 1 and T <b> 2 of the tank body 20 in the predetermined range R <b> 1 from the ceiling portion 22 </ b> A toward the equator line B. Cut so as to be parallel to the normals H1 and H2 from the positions C1 and C2.

  On the other hand, in the predetermined range R2 toward the equator line B below the predetermined range R1, the cut surface of the tank body 20 is perpendicular to the cut lines C1 to I4 from the cutting positions C3 to C6 with respect to the equator plane B1 surrounded by the equator line B. Cut so that they are parallel.

  Specifically, as shown in FIG. 4, in the upper cutting process, the burner fusing machine 40 is positioned at a cutting position C1 for cutting the ceiling portion 22A of the upper hemisphere 22 of the tank body 20, and cutting is performed from this portion. Start.

  In the present embodiment, the burner fusing machine 40 is attached to and operated by a heavy machine (not shown) in which the moving direction of the burner fusing machine 40 is set based on the size and shape of the tank main body 20. The upper hemisphere 22 of the tank body 20 spirals up to the upper edge 26a of the belt portion 26 while sequentially moving the cutting position from C1 to C6 as it gradually moves from the ceiling portion 22A of the upper hemisphere 22 toward the equator line B. Cut continuously.

  In particular, in the present embodiment, the tank body 20 is cut so that the cut surface has an inclination close to the vertical direction P as the cutting position by the burner cutting machine 40 shifts to C3 to C6. That is, the cutting is performed while gradually inclining the jet direction of the burner at the cutting positions C3 to C6 by the burner cutting machine 40 in the vertical direction P.

  Specifically, as shown in the schematic cross-sectional view of the cutting position C1 in FIG. 5 (a) and the schematic cross-sectional view of the cutting position C3 in FIG. 5 (b), the injection by the burner fusing machine 40 is illustrated at the cutting position C1. 3 is input perpendicularly to the tangent line T1 along the injection line a1 corresponding to the normal line H1.

  By this injection, the upper hemisphere 22 of the tank main body 20 is cut in a predetermined range R1 shown in FIG. 4, and a pair of cut end faces 22a, 22a facing each other in parallel with the jet line a1 is formed, and this pair of cut end faces 22a. , 22a constitute a cut surface of the upper hemisphere 22 of the tank body 20.

  On the other hand, at the cutting position C3, the injection by the burner fusing machine 40 is inclined by a predetermined angle θ1 so as to approach the vertical direction P from the normal H3 from the cutting position C3 on the tangent line T3, and in FIG. It is input along an injection line a2 that virtually corresponds to the perpendicular line I1 and is inclined in a direction away from the vertical direction P by a predetermined angle θ2 with respect to the tangent line T3.

  By this injection, the upper hemisphere 22 of the tank body 20 is cut in a predetermined range R2 shown in FIG. 4, and a pair of cut end faces 22b and 22b having an inclination close to the vertical direction P facing each other in parallel with the injection line a2. The pair of cut end surfaces 22b and 22b constitute a cut surface of the upper hemisphere 22 of the tank body 20.

  As described above, when the upper hemisphere 22 of the tank body 20 is continuously cut spirally in the predetermined range R1, the cut end surface 22a on the cut piece side and the cut end surface 22a on the upper hemisphere 22 side are cut without interfering with each other. The piece descends toward the inside of the tank body 20 by its own weight.

  On the other hand, when the upper hemisphere 22 of the tank body 20 is continuously cut in a spiral manner within the predetermined range R2, the tank body 20 is slid so that the cut end surface 22a on the cut piece side slides down on the cut end surface 22a on the upper hemisphere 22 side. Descends to the inside. Therefore, the cut piece does not diffuse toward the outside of the tank body 20.

  Further, in the present embodiment, as shown in FIG. 4, when the upper hemisphere 22 of the tank body 20 is spirally cut from the ceiling portion 22A toward the equator line B in the upper cutting process, Cut so that the cutting interval is gradually narrowed as it moves.

  Specifically, the cutting width w1 is cut during the transition from the cutting position C1 to the cutting position C2, and the cutting width w2 smaller than the cutting width w1 is set during the transition from the cutting position C2 to the cutting position C3. Cut to have.

  During the transition from the cutting position C3 to the cutting position C4, the cutting is performed so that the cutting width w3 is narrower than the cutting width w2, and during the transition from the cutting position C4 to the cutting position C5, the cutting width w4 is smaller than the cutting width w3. Cut to have. Further, during the transition from the cutting position C5 to the cutting position C6, the cutting is performed so that the cutting width w5 is narrower than the cutting width w4.

  That is, as it moves to the cutting positions C1 to C6, it is continuously cut in a spiral shape so that the cutting width gradually decreases to w1 to w5. In this way, by gradually narrowing the cutting width as it moves to the equator line B, when the compressive stress acting on the metal plate material by being formed into a spherical shape is released by cutting, The reaction force of the acting compressive stress can be suppressed.

  Therefore, the cut piece of the upper hemisphere 22 of the tank body 20 continuously cut in a spiral shape descends toward the inside of the tank body 20 without diffusing to the outside of the tank body 20. Specifically, as shown in FIG. 1 (d), the cut piece D <b> 1 descends through an opening 25 </ b> C formed in the lower hemisphere 24 of the tank body 20 and reaches the ground G below the tank body 20. Laminated in a spiral.

  The laminated cut pieces D1 are cut to a size that can be easily transported on the ground G, and are transported and discarded.

  Next, the lower cutting process will be described. As shown in FIG. 4, in the lower cutting step, the burner fusing machine 40 is positioned at a cutting position C7 where the opening edge 25c of the opening 25C of the lower hemisphere 24 of the tank body 20 is cut off from the tank body 20, and this portion Start cutting from.

  In the lower cutting step, the lower hemisphere 24 of the tank body 20 is moved to the belt while the cutting position is sequentially moved from C7 to C9 as it gradually moves from the opening 25C side of the lower hemisphere 24 of the tank body 20 toward the equator line B. Cut continuously and spirally to the lower edge 26b of the portion 26.

  In particular, in this embodiment, when the lower hemisphere 24 of the tank body 20 is spirally cut from the edge 25c of the opening 25C toward the equator line B, the cutting interval is gradually narrowed as the equator line B is shifted. Cut so that.

  Specifically, during the transition from the cutting position C7 to the cutting position C8, cutting is performed so as to have a cutting width w7 that is narrower than the cutting width w6 when cutting at the cutting position C7, and from the cutting position C8 to the cutting position C9. And the cutting width w8 is narrower than the cutting width w7.

  That is, as the cutting position shifts to C7 to C9, the cutting is continuously performed in a spiral shape so that the cutting width gradually decreases to w6 to w8. In this way, by gradually narrowing the cutting width as it moves to the equator line B, when the compressive stress acting on the metal plate material by being formed into a spherical shape is released by cutting, The reaction force of the acting compressive stress can be suppressed.

  Accordingly, the cut piece of the lower hemisphere 24 of the tank body 20 that is continuously cut in a spiral shape descends toward the inside of the tank body 20 without diffusing outwardly from the tank body 20. The cut piece D2 lowered in this way is spirally stacked on the ground G below the tank body 20, as shown in FIG.

  The laminated cut pieces D2 are cut into a size that can be easily transported on the ground G, and are transported and discarded.

  After the spiral cutting process constituted by the upper cutting process and the lower cutting process, the process proceeds to the belt part dismantling process. As shown in FIG. 1 (e), the tank body 20 is supported by the leg portion 30 with the belt portion 26 left uncut after the spiral cutting step is executed. In the belt part disassembly process, the tank part 20 is finally disassembled by cutting the belt part 26.

  Specifically, the burner fusing machine 40 is run along a weld line 26c that joins a plurality of metal plate materials, and is sequentially cut and disassembled to become a plurality of metal plate materials. At this time, a portion to be cut to be a plate material is gripped by a heavy machine or the like (not shown) and placed on the ground G after cutting.

  After the belt portion 26 is disassembled and the tank body 20 is finally disassembled, the disassembly work of the tank 10 is completed by disassembling the leg portion 30.

  Thus, in the present embodiment, the cut portion 25A on the bottom 24A side of the tank body 20 is disassembled on the ground G while being supported by the ground G and the tank body 20, and the upper hemisphere 22 of the tank body 20 and Since the lower hemisphere 24 is cut in a spiral shape, the dismantling work of the worker at a high place is avoided as much as possible, and the safety of the dismantling work of the tank 10 by the worker is ensured.

  Moreover, in the upper cutting process, when the upper hemisphere 22 is cut in a spiral shape, the cutting is performed while gradually inclining the jet direction of the burner at the cutting positions C3 to C6 by the burner cutting machine 40 in the vertical direction P. Since the cut piece of the hemisphere 22 is cut so as to descend to the inside of the tank main body 20, the cut piece does not diffuse outward, which may affect a house or the like existing in the vicinity where the tank 10 is located. Absent.

  In the lower cutting step, the cutting is performed so that the cutting interval is gradually narrowed as it moves to the equator line B. Therefore, the reaction force acting on the cutting piece is suppressed, and the cutting piece does not diffuse out of the tank body 20. In addition, there is no influence on the houses existing around the tank 10.

  Therefore, the safety of the surrounding housing etc. where the tank 10 is located is ensured, and the safety of the dismantling work of the tank 10 is improved.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. Although the case where the tank main body 20 is cut by the burner fusing machine 40 has been described in the above embodiment, the tank main body 20 may be cut by a cutting tool that performs cutting by water pressure or physical cutting by an electric saw or the like.

  In the above embodiment, in the spiral cutting process, the lower cutting process is executed after the upper cutting process. However, the upper cutting process may be executed after the lower cutting process.

10 tanks (large storage tank)
20 Tank body (storage tank body)
22 Upper hemisphere 22A Ceiling part 24 Lower hemisphere 24A Bottom part 25A Cutting part 25B Remaining part 26 Belt part 40 Burner fusing machine x Latitudinal line B Equatorial line C1-C9 Cutting position P Vertical direction w1-w8 Cutting width

Claims (4)

In the dismantling method of the large storage tank having a storage tank body formed in a spherical shape, and disassembling the bottom of the storage tank body of the large storage tank that is installed away from the ground,
Cutting the bottom side of the storage tank body leaving a part and bending the cut portion downward to ground the ground,
A dismantling method for a large storage tank, comprising disassembling sequentially by cutting the cut portion into a plurality of plates in a state where the cut portion grounded to the ground is grounded. Dismantling a large storage tank having a storage tank body formed in a spherical shape and spirally cutting the storage tank body of the large storage tank installed away from the ground downward from the top of the storage tank body In the method
A method for disassembling a large-sized storage tank, wherein cutting below a predetermined range from the upper part of the storage tank main body to the lower side is performed such that the cut surface has an inclination close to the vertical direction. A storage tank body formed in a spherical shape, and the storage tank body of the large storage tank installed away from the ground is spiraled from above or below in the installed state of the storage tank body toward the equator line. In the dismantling method of the large storage tank to be cut,
The cutting is
A dismantling method for a large storage tank, characterized in that the cutting interval of the storage tank body is gradually narrowed as it moves to the equator line. In a dismantling method of a large storage tank having a storage tank body formed in a spherical shape, and disassembling the storage tank body of the large storage tank that is installed away from the ground,
A bottom part dismantling step of cutting the bottom side of the storage tank body, leaving a part, bending the cut part downward to ground the ground, and sequentially disassembling the cut part grounded to the ground. When,
A spiral cutting step that spirally cuts from above or below the tank body toward the equator line after the bottom dismantling step,
Cutting in the spiral cutting step is
Performing cutting toward the equator line below the predetermined range from the upper part of the storage tank body downward so that the cutting surface has an inclination close to the vertical direction,
The cutting from the lower side of the storage tank body to the upper side is performed so that the cutting interval is gradually narrowed as it moves to the equator line.
A method for dismantling a large-sized storage tank.

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