JP2011001077A - Method for executing floating roof demolition work of floating roof type storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for executing the floating roof demolition work, which continuously cuts a deck plate of a floating roof in a spiral manner and successively lowers the cut deck plates onto a bottom plate, taking into consideration of reduction and execution properties of temporary equipment and materials, and safely executing the demolition and withdrawal of the floating roof with excellent workability.SOLUTION: A floating roof 5 is fixed at the predetermined height position and supported by a deck support 12, and accessory members provided on upper and lower parts of the floating roof 5 are demolished and withdrawn. Thereafter, a deck plate 6 of the floating roof is cut into a continuous spiral strip 21 of the predetermined width using a cutting device on the floating roof while the load of the floating roof is supported by the deck support 12 from a center to the outer circumference or from the outer circumference to the center and across the center. The continuous spiral strip 21 is successively lowered onto a bottom plate 2 while disassembling the deck support 12. Then, the spiral strip 21 is cut into short pieces of the predetermined length so as to be easily carried out, and conveyed for withdrawal.

Description

  The present invention relates to a floating roof dismantling construction method for a floating roof storage tank for constructing a floating roof dismantling work in order to repair or replace the floating roof of the floating roof storage tank.

Floating roof storage tanks are usually used when the floating roof is held in a predetermined height position on the bottom plate when corrosion or damage occurs on the floating roof, or when earthquake resistance or durability is improved. Demolition work such as repair and replacement.
For this dismantling work, for example, when repairing or replacing a floating roof with a single deck structure, when changing a floating roof with a single deck structure to a floating roof with a double deck structure, or a storage tank with an internal floating lid, that is, a dome roof or There are cases where the floating roof installed inside the storage tank with a corn roof is repaired, replaced, or modified.

FIG. 8 is an example of a floating roof type storage tank having a general single deck structure.
A large floating roof storage tank 1 for storing crude oil and other volatile and flammable liquids floats on the bottom of a circular flat plate 2, a cylindrical side plate 3, and a storage liquid 4 inside the side plate 3. It is formed from a single plate, that is, a floating roof 5 having a single deck structure.
The floating roof 5 is formed so as to suppress evaporation of the storage liquid 4 and prevent the rainwater or foreign matter from being mixed into the storage liquid 4. The floating roof 5 includes a single thin steel plate deck plate 6, The deck plate 6 is formed from an outer peripheral pontoon 7 of an annular box around the outer periphery.
In the gap between the outer peripheral pontoon 7 and the inner surface of the side plate 3, a sealing device 8 for maintaining airtightness and a rain screen 9 are provided on the upper portion thereof. A roof drain 10 that collects rainwater falling on the floating roof 5 at the center of the deck plate 6 and drains it to the outside of the storage tank, and an additional member such as a base heater 11 as necessary.

  Generally, when replacing or repairing the floating roof part or the whole shown in FIG. 8, the floating roof 5 having a single deck structure is positioned at a predetermined height above the bottom plate 2 as shown in FIGS. 9 and 10. The deck plate 12 and the temporary pontoon 7 are cut on the pedestal 13.

FIG. 9 is an overall explanatory view showing a case of lifting a cut piece of the floating roof 5 using the crane 14 and carrying it out in an example of the conventional floating roof dismantling construction.
In the case of the floating roof type storage tank 1 that is open at the top, a crane 14 is installed outside the storage tank as shown in FIG. 9, and the disassembled floating roof 5 is lifted by the crane 14 beyond the side plate 3. It is removed from the storage tank and removed.

FIG. 10 is an overall explanatory diagram showing a case where a cut piece of the cut floating roof 5 is carried out from the side manhole 15 of the storage tank to the outside of the storage tank in another example of the conventional floating roof dismantling construction work.
In the case where there is a roof above (not shown) or the case shown in FIG. 10 where a crane is not used, each cut piece cut with the floating roof 5 supported at a predetermined height is lowered onto the bottom plate 2. It is carried out from the side manhole 15 to the outside of the storage tank.

Furthermore, in consideration of safety and reduction of temporary equipment, the floating roof dismantling construction method that enables the dismantling and removal of the floating roof with good workability in the safety work at a low position near the bottom plate is There is an invention of Japanese Patent Application No. 2009-111354 “Floating roof dismantling construction method for floating roof storage tank” by the patent applicant.
In the present invention, as shown in FIG. 11, the floating roof 5 is fixedly supported by the deck support 12 at a predetermined height position, the lowering device 16 is attached to the upper end position of the deck support 12, and the deck support 12 is positioned near the lower end. After the stop 17 is provided, and then the floating roof 5 is lowered along the deck support 12 as shown by the broken line in the figure, the deck plate 6 of the floating roof 5 is cut and removed at a low position near the bottom plate 2 (not shown) This is the construction method.

  In addition, the invention disclosed in Japanese Patent Laid-Open No. 2-219781 “Method of dismantling a floating roof tank” has at least one traction member attached to the edge of a deck installed in the tank body, A method for dismantling a floating roof in which the pulling member extraction hole is provided at a predetermined position, the pulling member is pulled, and a rotational force is applied to the deck so that the deck post is brought down.

  Further, in the conventional method disclosed in Japanese Patent Application Laid-Open No. 8-60893, a method of cutting and dismantling a large storage tank is a spiral shape in which the ceiling portion of the outer shell member of the large storage tank and the subsequent lower side portion spread from the position near the center of the ceiling portion at a predetermined interval. There is a method in which the outer shell member is disassembled while being sequentially cut along a line and sequentially being lowered downward from the starting end of the cut portion.

Japanese Patent Laid-Open No. 2-219781

JP-A-8-60893

  In the conventional floating roof dismantling method shown in FIG. 9, the crane 14 is used to carry out the cut pieces. In addition to the deck support 12, a lot of temporary mounts 13 are required, and the disassembled weight member is lifted. The task of crossing high side plates was also difficult.

  In addition, in the conventional floating roof dismantling construction method shown in FIG. 10, the dismantling work is performed with the floating roof held at a predetermined height on the bottom plate, and the cut piece is carried out using the manhole 15 of the storage tank. Since the deck support 12 and the temporary mount 13 are used to perform the cutting work while holding the floating roof 5 at a position higher than the height, there is a case where the work becomes a high place and there is a risk of falling. Moreover, the operation | work which drops the cut | disconnected weight member on the baseplate 2 was also difficult.

  Furthermore, the invention of Japanese Patent Application No. 2009-111354 “Floating Roof Dismantling Construction Method for Floating Roof Type Storage Tank” by the applicant of the present patent application shown in FIG. Although it is a floating roof dismantling construction method that can dismantle and remove the floating roof with good workability, it is necessary to mount a number of lowering devices 16 on the deck support 12, and the deck is lowered to an average over a wide range. There was a need to do.

  Further, the invention of the conventional Japanese Unexamined Patent Publication No. 2-219781 “floating roof dismantling method of floating roof type tank” is a method of applying a rotational force to the floating roof deck and defeating the deck post at a low position, It was necessary to cut and open the side plate, and it was difficult to defeat the entire deck post simultaneously and on average. Furthermore, since the deck host is brought down at once, the bottom plate may be damaged, which is not suitable for a method of reusing the bottom plate.

  Furthermore, the conventional Japanese Patent Laid-Open No. 8-60893, “Method of cutting and dismantling large storage tanks” is suitable for cutting and dismantling of spherical storage tanks, but a cutting device is used when dismantling floating roofs of floating roof storage tanks. It was not suitable for running around the storage tank or pulling out a cut piece outside the storage tank.

The object of the present invention was made in view of the above-mentioned problems of the prior art, and in consideration of reduction of temporary equipment and workability, the floating roof deck board was continuously cut into a spiral shape. It is intended to provide a method for dismantling floating roofs that can be moved down to the bottom plate in order to allow dismantling and removal of floating roofs for safe work with good workability.

  In the floating roof dismantling construction method according to claim 1, the floating roof is fixedly supported by a deck support at a predetermined height position, and the attachment members provided at the upper and lower portions of the floating roof are dismantled and removed, and then the floating roof Using the cutting device, the floating roof deck plate is directed from the center to the outer periphery, or from the outer periphery to the center, and the load is supported by the deck support so as to straddle the center. Cut the plate, remove the deck support, ground the continuous spiral strips on the bottom plate in sequence, then cut the spiral strips into short pieces of a predetermined length for easy removal It is.

  In the floating roof dismantling construction method according to claim 2, the cutting device is moored and guided by a wire wound around a central axis on the deck plate of the floating roof so as to cut into a spiral strip while running in a spiral shape. Is formed.

The floating roof dismantling construction method according to claim 3 is formed such that the cut spiral strips are sequentially cut into short pieces and transported on a carriage traveling and moving on the bottom plate.

  In the floating roof dismantling construction method according to claim 1, the floating roof is fixedly supported by a deck support at a predetermined height position, and the attachment members provided at the upper and lower portions of the floating roof are dismantled and removed, and then the floating roof Using the cutting device, the floating roof deck plate is directed from the center to the outer periphery, or from the outer periphery to the center, and the load is supported by the deck support so as to straddle the center. The continuous spiral strips are dropped and grounded on the bottom plate sequentially while removing the deck support, and then the spiral strips are cut into short pieces of a predetermined length for easy removal. Because it is possible to continuously cut and descend the cut strip-like strips one after another, there is no need to worry about dropping people or things involved in the cutting work, so it is safe and reduces equipment such as temporary mounts and descent devices. It is possible, Good work efficiency because sequentially removed to remove by cutting the cut pieces at low locations on the bottom plate Kkisapoto, safety is secured.

  In the floating roof dismantling construction method according to claim 2, the cutting device is moored and guided by a wire wound around a central axis on the deck plate of the floating roof so as to cut into a spiral strip while running in a spiral shape. Thus, the helical strip having a predetermined width can be continuously cut with good workability, and the cutting device can be driven with a stable trajectory and speed to continue the cutting work with good workability.

Since the floating roof dismantling construction method according to claim 3 is formed so that the strip cut into a spiral shape is sequentially cut into a short piece on a carriage that travels on the bottom plate and transported, it is low in the vicinity of the bottom plate. Since a series of operations from cutting at the position to loading and unloading are performed using a carriage, handling of the cut pieces does not become complicated, and the work efficiency is improved with safety work, and the cost and work period are shortened.

It is side surface explanatory drawing which shows the condition where the floating roof of the floating roof dismantling construction method which concerns on this invention is fixed to a predetermined position, and each attachment member of floating roof upper and lower parts is demolished and removed. It is plane explanatory drawing which shows the condition which cuts the deck board of a floating roof to a spiral shape from a center part to an outer periphery, after dismantling and removing the attachment member of the floating roof upper and lower in the floating roof demolition construction construction method which concerns on this invention. It is side surface explanatory drawing of FIG. In embodiment of the floating roof dismantling construction method concerning this invention, it is plane explanatory drawing which shows the condition which cut | disconnects the deck board of a floating roof in a spiral shape toward the center from an outer peripheral part. It is side surface explanatory drawing of FIG. It is explanatory drawing which shows the example which provided the cutting device used for the floating roof dismantling construction method concerning this invention. It is explanatory drawing which shows the example which provided the carrying-out apparatus used for the floating roof demolition construction method which concerns on this invention. It is a whole side explanatory view showing a floating roof type storage tank provided with a general single deck structure floating roof. It is whole explanatory drawing which shows the example which carries out a cutting piece using a crane by the floating roof demolition construction construction method of a prior art example. It is the whole explanatory drawing which shows the example which carries out a cut piece using the manhole of a storage tank by the floating roof demolition construction construction method of a prior art example. It is side explanatory drawing which shows the condition which installs a raising / lowering apparatus in a deck support by the comparative example concerning the applicant of the floating roof dismantling construction method, and descends a floating roof using this raising / lowering apparatus subsequently.

An embodiment of a floating roof dismantling construction method according to the present invention will be described with reference to FIGS. 1 to 7.
This embodiment shows an example of dismantling the single-deck structure floating roof type storage tank illustrated in FIG. 8, and the same reference numerals are used for the same terms throughout FIGS. The part is omitted.
In the illustrated example, a single-deck floating roof storage tank will be described. However, it is not limited to a single-deck floating roof storage tank, but in the case of a double-deck floating roof storage tank or a floating roof of a storage tank with an internal floating lid. Needless to say, it can be applied to the dismantling work.
1 is a floating roof type storage tank, 2 is a circular flat bottom plate, 3 is a cylindrical side plate, 5 is a single-deck floating roof, and 6 is a deck plate. 7 is an outer peripheral pontoon of the annular box, 8 is a sealing device that keeps the gap between the outer peripheral pontoon 7 and the inner surface of the side plate 3 airtight, and 9 is a rain shield. 10 is a roof drain extending from the center of the deck plate 6 of the floating roof 5 to the outside of the storage tank, and 11 is a base heater provided as necessary.

FIG. 1 is an overall side view illustrating a situation where the floating roof of the floating roof dismantling construction method according to the present invention is fixed at a predetermined position and the upper and lower attachment members of the floating roof are dismantled and removed.
As shown in the figure, the floating roof 5 is fixed to a predetermined height position, for example, the position of the high deck set to the highest position by using the deck support 12, and an outer peripheral pontoon 7 provided on the deck board 6 as shown by a broken line A. Then, the attachment members such as the seal member 8 and the rain shield plate 9 are cut, and the attachment members such as the roof drain 10 and the base heater 11 provided under the deck plate 6 are cut as shown by the broken line B, and further cut into pieces. The lightened cut piece is removed from the manhole 15 to the outside of the storage tank.
Although not shown, in the case of a storage tank with an internal floating lid, there may be no attached member at the lower part of the floating roof such as a roof drain.

  In this case, the outer peripheral pontoon 7, the seal member 8, and the rain guard plate 9 shown by the broken line A are cut on the deck plate 6 so as not to be fine and heavy, so that they can be lowered by a safe operation without fear of dropping. Further, the roof drain 10 and the base heater 11 shown by the broken line B are cut in a high deck state where the ceiling under the deck plate 6 is high, so that the workability is good, and the carrying out from the manhole 15 can be performed safely and with good workability. .

FIG. 2 shows the floating roof dismantling construction method according to the present invention. Following FIG. 1, the state in which the deck plate 6 of the floating roof is continuously cut in a spiral shape from the central portion toward the outer peripheral direction. FIG.
Reference numeral 18S denotes a cutting start point at the center, and a continuous spiral strip 21 is cut by cutting like a spiral cutting line 20 indicated by a two-dot chain line toward a cutting end point 19E on the outer peripheral portion of the deck plate 6. Form.

The spiral cutting line 20 avoids the position of the deck support 12 so that the spiral spreads from the center part, supports the load on the deck support 12 and advances toward the outer periphery so as to straddle the center, and the cutting proceeds. The deck support 12 is sequentially removed as the spiral strip 21 is formed. The spiral strip 21 from which the deck support 12 has been removed has a predetermined width that gradually descends due to its own weight and sequentially lands on the bottom plate 2.
A cutting machine and an operator (not shown) are supported on the deck board of the floating roof and are supported with a certain load and proceed backward according to the cutting.

FIG. 3 is an explanatory side view of FIG.
When the cutting is started in a spiral shape from the cutting start point 18S at the center of the deck plate 6 toward the outer periphery and the deck support 12 near the center is removed, the spiral strip 21 is gradually lowered by its own weight and sequentially on the bottom plate 2. Landing, that is, soft landing soft landing.

FIG. 4 shows another embodiment of the floating roof dismantling construction method according to the present invention. Following FIG. 1, the floating roof deck plate 6 is continuously cut in a spiral shape from the outer periphery toward the center. FIG.
Reference numeral 18S denotes a cutting starting point, and a helical strip 21 is obtained by cutting like a helical cutting line 20 indicated by a two-dot chain line from the outer peripheral portion of the deck plate 6 toward the central cutting end point 19E.

The helical cutting line 20 avoids the position of the deck support 12 so as to be sucked into the spiral from the outer peripheral portion, advances toward the center so that the load is supported on the deck support 12 and straddles the center, and the cutting ends. The deck support 12 is removed in order. The spiral strip 21 from which the deck support 12 has been removed has a predetermined width that gradually descends due to its own weight and sequentially lands on the bottom plate 2.
The cutting machine and the worker (not shown) are supported by the load on the floating roof and move backward according to the cutting.

FIG. 5 is an explanatory side view of FIG.
When cutting is started in a spiral shape from the cutting start point 18S of the outer peripheral portion of the deck plate 6 toward the center and the deck support 12 in the vicinity of the outer periphery is removed, the spiral strip 21 is gradually lowered by its own weight and sequentially on the bottom plate 2 Landing, that is, soft landing soft landing.

Drawing 6 is an explanatory view showing the example which provided the cutting device used for the floating roof demolition construction construction method concerning this invention.
The cutting machine 24 is moored to a wire 23 that is wound around a center drum 22 that is a central axis on the deck plate 6 of the floating roof, and a stable trajectory and speed are adjusted while the wire 23 is guided while being stretched in the radial direction of the outer periphery. While traveling in a spiral shape, cutting is performed so that a continuous spiral cutting line 20 is obtained.
At this time, the wire 23 is stretched high or the upper end of the deck support 12 is lowered so that the turning of the wire 23 stretched for traveling of the cutting machine 24 is not disturbed by the deck support 12 extending on the deck plate 6. Keep it.
In the example shown in FIG. 6, when the cutting machine 24 travels from the cutting start point 18 </ b> S of the outer peripheral portion and cuts along the spiral cutting line 20, the wire 23 is wound around the winding portion 25 of the center drum 22. Move in a spiral shape from the center toward the center. At this time, the winding length of the wire 23 around the center drum 22 is formed to be a predetermined width of the spiral strip 21.
Further, although not shown, when cutting is started from the center, the center drum is left, and the wire is wound back in a spiral shape while rewinding the wire.

FIG. 7 is an explanatory view showing an example in which an unloading device used in the floating roof dismantling construction method according to the present invention is provided.
The cut spiral strip 21 is softly landed on the carriage 26, that is, is soft-landed and loaded, and is cut into a short piece 27 of an appropriate length that can be easily transported on the carriage 26 that travels on the bottom plate 2. It is formed so as to be sequentially cut and subsequently transported by a carriage 26 and carried out from the manhole 15 to the outside of the storage tank.
If the cart 26 has a width approximately equal to the width of the band plate 21 and a plurality of vehicles having good running performance and operability are prepared, the work efficiency is further improved.

As described above, the floating roof dismantling construction method according to the present invention cuts a strip of a predetermined width on the deck board 6 supported by the deck support 12, so that the cutting and dismantling of the floating roof is a safe work. In addition, while removing the deck support 12 one after another, the spiral strip 21 is sequentially lowered onto the bottom plate 2 and landed, so there is no risk of people or objects falling during the cutting operation. Secured. As described above, the cutting work on the deck board 6 and the cutting / conveying work under the deck board 6 do not coincide with each other, which is a safety work.
Although not shown in the figure, it is possible to obtain a safer and more secure relief by installing a temporary load support base that can be moved as necessary near the lower part of the floating roof cutting point, and sequentially removing and removing the floating roof according to the cutting.

In this way, the deck plate 6 of the floating roof 5 is cut into a spiral shape to form a spiral strip 21, and this spiral strip 21 is sequentially softly landed on the bottom plate 2, that is, soft-landed, and then sequentially cut into short pieces 27. And since this short piece 27 can be conveyed with sufficient workability and carried out of the storage tank, work safety and workability are improved.
In addition, since a large temporary mount and a plurality of descent devices are not required, temporary equipment can be reduced, resulting in cost reduction and construction time reduction.

The floating roof dismantling construction method according to the present invention includes construction work such as replacement and repair of a floating roof with a single deck structure or a double deck structure, conversion of a floating roof with a single deck structure into a floating roof with a double deck structure, and internal floating It can be applied to modifications to improve the seismic resistance of storage tanks with lids, that is, floating roofs with dome roofs and cone roofs.

1 Floating roof storage tank
2 Bottom plate
3 Side plate
4 Stock solution
5 Floating roof
6 deck boards
7 peripheral pontoon
8 Sealing device
9 Rain guard
10 Roof drain
11 Base heater
12 deck support
13 frame
14 crane
15 Manhole
16 Descent device
17 Stopper

18S cutting origin
19E End of cutting
20 helical cutting line
21 Spiral strip
22 Center drum
23 wires
24 cutting machine
25 Winding part
26 trolley
27 Short pieces
28 Cutting position

Claims (3)

After the floating roof is fixedly supported by the deck support at the predetermined height position, the attachment members provided on the upper and lower parts of the floating roof are dismantled and removed, and then the floating roof deck board is used by using a cutting device on the floating roof. From the center to the outer periphery, or from the outer periphery to the center, support the load on the deck support and cut it into a continuous strip-shaped strip with a predetermined width so as to straddle the center and remove this deck support. A floating roof dismantling construction method characterized in that the spiral strip is lowered and grounded sequentially on the bottom plate, and then the spiral strip is cut into a short piece of a predetermined length that is easy to carry out and removed. 2. The cutting device according to claim 1, wherein the cutting device is formed so as to be cut into a helical strip while running in a helical shape by being moored and guided by a wire wound around a central axis on the deck plate of the floating roof. Floating roof dismantling construction method. 3. The floating roof dismantling construction method according to claim 1 or 2, wherein the cut spiral strip is formed so as to be sequentially cut into a short piece on a carriage traveling and moving on a bottom plate.