JP4839052B2 - Rotating dismantling method of storage tank - Google Patents

Description

The present invention relates to a rotational dismantling method for a storage tank for dismantling a storage tank having a small work area and a safe safety such as handling of fire, with good workability.

  A large storage tank having a cylindrical steel side plate peripheral wall needs to be dismantled for safety when it has been aged for many years after construction. In addition, there is a need to rebuild or dismantle due to changes in storage tank usage or location conditions.

When disassembling a conventional general cylindrical storage tank, although not shown in the figure, first, a total scaffold is temporarily installed on the entire outer periphery of the side wall of the cylindrical storage tank, and an operator cuts the side panel peripheral wall by gas cutting or the like on the scaffold. Then, the blocked side plate peripheral wall is lifted and lowered by a heavy machine such as a crane, and the dismantling work is carried out sequentially from the height toward the lower part. The temporary scaffolding and dismantling from the height toward the bottom required large-scale safety measures such as fall prevention, safety nets, and fire scattering measures, and a large work space. In particular, in places where there are storage tanks and operating facilities for storing dangerous materials in the surrounding area, the working place is limited and strict safety measures are also required.

Therefore, in the conventional technology considering workability and safety, for example, the invention of “steel cylindrical structure side wall dismantling method” disclosed in Japanese Patent Publication No. 3-45187 related to the inventors of the present applicant. There is. The technology of the present invention cuts one round around the ground of the structure to be dismantled with a certain inclination with respect to the horizontal, arranges a load support roller on the entire circumference of the slope cut, and rotates the side wall on the roller. Then, the predetermined range at the bottom of the peripheral wall is cut, and the predetermined range is cut and removed while sequentially rotating the side wall.

Further, the invention disclosed in “Tank Dismantling Method” of Japanese Patent Application Laid-Open No. 10-2116 discloses that the lower end portion of the tank side plate has a sawtooth shape composed of an inclined portion and a vertical portion inclined in the same circumferential direction. The guide plate is separated from the bottom, and a guide roller is installed at this position so that the entire side plate is rotated little by little in the circumferential direction, and the side plate is disassembled while repeatedly being cut and rotated.

Further, the invention of the “disassembly repair method for the upper part of the cylindrical storage tank” disclosed in Japanese Patent Application Laid-Open No. 10-61246 by the applicant of the present application is such that only the upper part of the peripheral wall of the storage tank can be safely and efficiently disassembled and repaired at a fixed place. The upper peripheral wall is cut horizontally, the rollers are arranged at predetermined intervals, and the upper part is cut and disassembled and repaired while rotating.

Furthermore, the invention of the method of assembling the peripheral wall of the cylindrical tank disclosed in Japanese Patent Publication No. 2-33381 by the present applicant is as follows. First, the lowermost peripheral wall is assembled, and a roller is disposed on the upper edge of the upper peripheral wall. The departments are stacked in a certain place.

Japanese Examined Patent Publication No. 3-45187 JP-A-10-2116 JP-A-10-61246 JP-B-2-33821

The conventional dismantling method of storage tanks requires a temporary scaffolding with a large scale and a large number of members because the total scaffolding must be temporarily installed over the entire circumference of the storage tank and the side plate peripheral wall must be cut and removed. As for this total scaffold, assembly temporary work and dismantling removal work were complicated, and it took time, and the work efficiency was inevitably lowered. In addition, since the work of dismantling the peripheral wall of the storage tank and the work of dismantling and removing the scaffolding are performed in parallel, considerable consideration must be given to the safety of the work.

The invention technology of “steel cylindrical structure side wall dismantling method” disclosed in Japanese Patent Publication No. 3-45187, which takes into consideration workability and safety, does not require a huge temporary scaffolding or the like. This is a method of dismantling safely and efficiently in a low place near the ground, but a load support roller is placed around the entire circumference that is inclined with respect to the horizontal and cut once, and a predetermined range of the peripheral wall is rotated sequentially while rotating. Therefore, it is cumbersome and time-consuming to form the opening edges for the installation and movement of the rollers in the form of guide rails in order, and the stability of the inclined rotation movement during the rotation work is reduced. Consideration to hold was great.

In addition, the invention disclosed in “Tank dismantling method” of Japanese Patent Application Laid-Open No. 10-2116 performs most of the dismantling work on the ground, and does not require a high work or a large work platform, but the same for the tank side plate It takes effort and accuracy to smoothly form a sawtooth-shaped opening consisting of a sloped part and a vertical part, and work to replace the guide roller at this position and the entire side plate in the circumferential direction The rotating operation at the same time is complicated and time-consuming.

In addition, the invention disclosed in the "disassembly repair method for the upper cylindrical wall of the cylindrical storage tank" disclosed in Japanese Patent Laid-Open No. 10-61246 is for dismantling and repairing the upper peripheral wall of the large floating roof type cylindrical storage tank to which the wind girder is attached. This is a suitable method, and it is possible to disassemble and repair a predetermined place at a certain place safely and efficiently while rotating the upper part of the peripheral wall of the storage tank, but the work scaffold mounting work at a high place, the upper peripheral wall is cut horizontally The work of disposing a roller and the work of rotating the upper peripheral wall were difficult, and heavy equipment such as a crane was required to lift and suspend the replacement member.

Furthermore, the invention disclosed in “Cylinder tank peripheral wall assembling method” of Japanese Examined Patent Publication No. 2-333821 is arranged such that a roller is disposed on the upper edge of the lowermost peripheral wall and the upper peripheral wall portion is placed at a fixed place while rotating. Although it is an assembly method that excels in safety and work efficiency, it is not suitable for the dismantling method that requires heavy machinery such as cranes for lifting work and that dismantles and removes from above.

The object of the present invention has been made in view of the above-described problems of the prior art. When the surroundings of the tank to be disassembled are narrow and dangerous, it does not require a large-scale hypothetical scaffolding and is safe. It provides a rotating dismantling method for storage tanks with excellent workability.

The rotational dismantling method of the storage tank according to the present invention, when disassembling the cylindrical storage tank, a horizontal cutting line is marked over the entire circumference in the horizontal circumferential direction at a height that can be reached from the ground of the side wall of the side plate. A plurality of openings are provided so as to be separated over the entire circumference of the side plate at the lower part of the cutting line, a roller for supporting and rotating the load above the cutting line is disposed in the opening, and the side wall of the side plate is made a round along the cutting line. In addition, a dismantling work platform consisting of elevating stairs and a plurality of upper and lower work floors is erected at a predetermined position outside the storage tank, and the vertical height between the work floors is such that the thickness of the peripheral wall of the side plate is downward There is uppermost working floor and forming the same total thickness of the cutting height of the side plates to reduce the thus vertical height to increase upright spanned on the roof, dismantling of roof on the roof Using the uppermost work floor Retreat from the center to the outer periphery so as to peel off the roof plate, and disassemble the roof bone in the circumferential direction while rotating the storage tank with the roller, and then horizontally use the roller provided as described above to level the side plate peripheral wall To the lower work floor, move to the lower work floor, and then move to the lower work floor. And continue to disassemble the peripheral wall of the side plate from the top to the bottom, and cut the cutting height of the peripheral wall as the plate thickness of the peripheral wall of the side plate increases downward. The work to be performed is performed on the work floor according to the cutting height.

The rotational dismantling method of the storage tank according to the present invention, when disassembling the cylindrical storage tank, a horizontal cutting line is marked over the entire circumference in the horizontal circumferential direction at a height that can be reached from the ground of the side wall of the side plate. A plurality of openings are provided so as to be separated over the entire circumference of the side plate at the lower part of the cutting line, a roller for supporting and rotating the load above the cutting line is disposed in the opening, and the side wall of the side plate is made a round along the cutting line. In addition, a dismantling work platform consisting of elevating stairs and a plurality of upper and lower work floors is erected at a predetermined position outside the storage tank, and the vertical height between the work floors is such that the thickness of the peripheral wall of the side plate is downward There is uppermost working floor and forming the same total thickness of the cutting height of the side plates to reduce the thus vertical height to increase upright spanned on the roof, dismantling of roof on the roof Using the uppermost work floor Retreat from the center to the outer periphery so as to peel off the roof plate, and disassemble the roof bone in the circumferential direction while rotating the storage tank with the roller, and then horizontally use the roller provided as described above to level the side plate peripheral wall To the lower work floor, move to the lower work floor, and then move to the lower work floor. And continue to disassemble the peripheral wall of the side plate from the top to the bottom, and cut the cutting height of the peripheral wall as the plate thickness of the peripheral wall of the side plate increases downward. Because the work to be done is on the work floor according to the cutting height,
In case work area of the reservoir periphery to dismantle narrow poor workability are also in a case where there is a reservoir or equipment facilities in operation in ambient, without the need for such large-scale temporary scaffolding, the side plate wall Horizontally cut across the entire circumference in the horizontal circumferential direction at a height that is reachable from the ground, and provide a plurality of openings over the entire circumference of the side plate at the bottom of the horizontal cut, and the side plate above the horizontal cut in the opening. Since a roller for supporting and rotating the load is provided, disassembly can be performed with good workability by using this simple roller and a dismantling work platform that is installed in one place and the work floor height is changed . In this way, when there are dangerous goods in the surroundings or the safety aspects of fire handling are severely restricted, the storage tank can be safely dismantled without fire or cutting pieces scattered around the entire circumference of the storage tank. Temporary materials such as flameproof sheets and curing materials can also be reduced, and dismantling work can be performed safely and with good workability. In addition, since the rotation of the storage tank by the roller is performed horizontally at a low place, it is smooth and stable, and does not require a large heavy machine such as a crane that hangs up and down at a high place. Furthermore, the dismantling work is performed safely on the stable work floor of the stable dismantling work platform, and further, the dismantling of the storage tank progresses sequentially from the top to the bottom by one round rotation and moving to the lower stage. It can be disassembled efficiently with a short construction period. Thus, the lower side plate peripheral wall sequentially moves from the upper work floor to the lower work floor, and is disassembled while rotating the storage tank. In this case, the vertical height between the upper and lower work floors is a work in which the work of cutting with the cutting height reduced according to the increase in weight as the thickness of the peripheral wall of the side plate decreases downward is adjusted to the cutting height. Since it is on the floor, it is excellent in safety of cutting work that reduces the increase in weight, has good workability, and can be disassembled efficiently in a short time.

A method of rotating and dismantling a storage tank according to the present invention will be described with reference to FIGS. FIG. 1 is an embodiment showing the entire storage tank in which the rotary dismantling method is being constructed. FIG.2 and FIG.3 shows the condition which installed the roller in the side-plate surrounding wall of the storage tank to disassemble. 4 (a) and 4 (b) show the vicinity of the upper part of the dismantling work platform. FIG. 5 shows a plan layout around the site of the storage tank to be dismantled.

The cylindrical storage tank 1 to be disassembled is surrounded by an existing storage tank and a liquid barrier 14 on the three sides of the periphery as shown by hatching in the planar arrangement of FIG. 5, and the front faces a passage 15 that is convenient for workability and carrying out. ing. In such a place, it is difficult to assemble a temporary scaffold for dismantling around the entire periphery of the storage tank. Therefore, the dismantling base 7 is installed at one place in the vicinity of the passage 15 that is suitable for wide conveyance in the front, and the dismantling work is performed at this place. Thus, when the dismantling base 7 is installed in a wide place near the passage 15, the dismantling work and the member unloading are easy to perform, and sparks and cut pieces do not scatter from above around the storage tank. Eliminates the need for large-scale protective measures such as flameproof sheets for fire prevention and curing.

As shown in FIG. 1, a dismantling gantry 7 is assembled vertically along the side plate peripheral wall 3 in the vicinity of the side plate peripheral wall 3 of the storage tank 1 to be disassembled and in a place facing the passage 15 shown in FIG. 5. Although not shown in the figure, when dismantling platforms are provided at two positions opposite to the side wall of the side plate, the dismantling operation can be performed at two places, and the storage tank can be rotated by half a round and a left and right reciprocating half rotation. Since it is good, work efficiency can also be improved and the dismantling period can be halved.

As shown in FIGS. 1 to 3, first, a horizontal cutting line 4 is ruled in the horizontal direction over the entire circumference in the circumferential direction at a low position where the side wall 3 can reach. Next, a plurality of openings 5 are cut out in the circumferential direction at appropriate positions separated from the pitch 1 meter by several meters in the lower side plate peripheral wall 3 of the ruled horizontal cutting line 4. Subsequently, a roller 6 is installed in the opening 5.

As shown in FIG. 2, a rotating roller 6a that rotates while supporting a load is installed in the small notch opening 5a, and a driving roller 6b that rotates by electric feeding is installed in the large notch opening 5b. The driving roller 6b of the large notch opening 5b is provided as appropriate alternately or partially with the rotating roller 6a of the small notch opening 5a, and is provided so that the upper side plate peripheral wall 3 rotates smoothly and horizontally.

As shown in FIGS. 2 and 3, the lower end of the roller 6 of the opening 5 of the side plate peripheral wall 3 located below the horizontal cutting line 4 is provided with a protector 12 and a load support for reinforcement along the circumferential direction. A bracket 13 is provided. After the roller 6 can support the load on the side plate peripheral wall 3, the side plate peripheral wall 6 is cut once along the horizontal cutting line 4, and the roller 6 supports the load on the side plate peripheral wall 3. .

As shown in FIG. 4, the dismantling platform 7 is assembled into a multi-stage frame using pipe material or molding material. (A) is a side view near the upper part, and (b) is a plan view near the uppermost stage. 8 is a multi-stage work floor, 9 is an elevating staircase from the ground to the storage tank roof 2, 10 is an elevator that suspends a dismantling member, and 11 is a handrail for safety work. Although not shown in the drawings, the dismantling platform 7 is provided with a roof for measures against wind and rain, a sheet for measures against fire and fire, a net for measures for preventing falling objects, and the like.

The elevator 10 is not a heavy machine such as a large crane, but a lifting device such as a chain block, a wire, or a guide rail. Although illustration is omitted, if construction is carried out using an aerial work vehicle or a lifting lift instead of the dismantling platform 7, in addition to a significant improvement in economic effect, the safety of the work is also greatly improved. Can do.

After the side plate peripheral wall 3 is rotated horizontally using the roller 6 provided as described above, the dismantling work is sequentially performed using the work floor 8 of the dismantling platform 7, and after the dismantling is completed over one round, the lower stage The working floor 8 is further disassembled for one round, and then the lower floor working floor 8 is sequentially moved to continue the disassembling work of the side plate peripheral wall 3 from above to below.

The dismantling of the roof 2 uses the uppermost work floor 8 provided over the roof 2, retreats from the center toward the outer periphery so as to peel off the roof plate, and rotates in the circumferential direction while rotating the storage tank. Dismantle the roof bones. In the case of a floating roof type storage tank in which the roof 2 has already been lowered into the storage tank, the roof 2 is disassembled in the vicinity of the bottom of the storage tank, so that the disassembly work on the uppermost work floor 8 of the dismantling work platform 7 is performed. It becomes easy.

The lower side plate peripheral wall 3 sequentially moves from the upper work floor 8 to the lower work floor 8 and is disassembled while rotating the storage tank. In this case, the vertical height between the upper and lower work floors 8 is adjusted so that the cutting height is reduced and the weight increase is reduced as the plate thickness of the side plate peripheral wall 3 increases downward. You can consider ease.

As described above, the rotation of the storage tank by the roller 6 is performed horizontally at a low place, so that it is smooth and stable. In addition, since the lowering of the dismantling member is performed by the elevator 10 installed on the dismantling work platform 7, a large heavy machine such as a crane that hangs up and down like a conventional one is not required. Furthermore, since the dismantling work of the storage tank is performed on the stable work floor 8 of the dismantling work platform 7, it is a safe work, and the work progresses sequentially from the top to the bottom. Can be dismantled efficiently.

As described above, when the surroundings of the tank to be disassembled are narrow and workability is not good, or when there are storage tanks or equipment in operation in the surroundings, simple roller and disassembly without requiring a large temporary scaffold etc. Using the work platform, it is possible to stably dismantle downward sequentially. In addition, a dismantling work stand is erected on a predetermined place that is widely suitable for transport, and the dismantling work is performed on this dismantling work stand. Temporary materials such as sheets and curing materials can also be reduced, and dismantling work can be performed safely and with good workability.

Since the rotary dismantling method of the storage tank according to the present invention can be easily and safely performed when the surroundings are narrow and there are dangerous objects in the surroundings, it can be performed in the lower circumferential direction of various structures. It can be applied when dismantling work is performed at one place by installing a roller.

It is side explanatory drawing which shows the example of embodiment of the rotation dismantling method of the storage tank which concerns on this invention. It is a side view which shows the condition which installs a roller in a side-plate surrounding wall. It is a longitudinal cross-sectional view which shows the condition which installs a roller in a side plate surrounding wall. It is the side view (a) and top view (b) which show the upper part of a dismantling work stand. It is a top view of the site which shows the arrangement state of the storage tank to dismantle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Storage tank 2 Roof 3 Side board surrounding wall 4 Horizontal cutting line 5 Opening part 5a Notch opening part 5b Notch opening part 6 Roller 6a Rotating roller 6b Driving roller 7 Dismantling work stand 8 Work floor 9 Lifting staircase 10 Lifting machine 11 Handrail 12 Protector 13 Bracket 14 Breakwater 15 passage

Claims (1)

When disassembling the cylindrical storage tank, scribe a horizontal cutting line over the entire circumference in the horizontal circumferential direction at a height that can be reached from the ground of the side wall of the side plate, and isolate it over the entire side plate around the lower part of the cutting line. A plurality of openings are provided, a roller for supporting and rotating the load above the cutting line is disposed in the opening, the side plate peripheral wall is cut once along the cutting line, and then moved up and down to a predetermined position outside the storage tank. erected disassembly work platform consisting of upper and lower working floor of stairs and a plurality of stages, the upper and lower height between the working bed, small therefore vertical height to the thickness of the side plate wall weight increases downward to the top of the working floor and forming the cutting height combined flush side plates erected spanned on the roof, a working floor of the uppermost dismantling of roof provided spanned on the roof Use from the center to the outer periphery to peel off the roofing board Retreating and rotating the storage tank with the roller, dismantling the roof bone in the circumferential direction, then using the roller provided as described above, horizontally rotating the peripheral side wall of the side plate, Sequentially dismantle using the work floor, and after the dismantling has been completed over one round, move to the lower work floor, disassemble one more round, move to the lower work floor sequentially, and move from top to bottom. Continue the disassembly work of the peripheral wall of the side plate, and adjust the cutting operation to reduce the cutting height of the peripheral wall to match the cutting height as the plate thickness of the peripheral wall of the side plate increases downward A rotating dismantling method for storage tanks, characterized by being on the floor.