JPH09209585A - Tank dismantling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method which is capable of shortening a working period and reducing working cost without requiring high-position work for a long time and temporary installation of large-scale working scaffolds. SOLUTION: A temporary side plate 5 cylindrically formed with a smaller diameter than the inner diameter of a tank side plate 3 is standingly provided at a tank bottom 7 and a seal plate 6 is mounted on the whole periphery at the upper end of the temporary side plate 5 to be put in slide contact with the inner periphery of the tank side plate 3 with air tightness, so that pressure air is guided into a tank 1 to increase pressure in the tank 1 until the weights of the tank roof 2 and the tank side plate 3 are supported by air pressure. Work for removing the lower end of the tank side plate 3 cut at a lower position than the upper end of the seal plate 6 and purging a proper amount of pressure air in the tank 1 to drop the tank roof 2 and the tank side plate 3 is repeated. Then, almost all of the tank side plate 3 is disassembled, followed by the tank roof 2 seated on a tank bottom 7.

Description

Detailed Description of the Invention

[0001]

The present invention relates to petroleum, LPG, L
The present invention relates to a tank dismantling method for storing NG or the like.

[0002]

2. Description of the Related Art When rebuilding or removing a large tank for storing petroleum, LPG, LNG or the like, it is necessary to disassemble the tank into a size that can be transported by loading it on a truck or the like. .

Conventionally, in the case of disassembling such a tank, a large-scale work scaffold is temporarily installed around the tank, and the worker uses the work scaffold in order from the upper structure of the tank to a proper size with a burner. It was cut into pieces and hung on the ground with a large crane.

[0004]

However, in such a conventional dismantling method, work in a high place where workability is poor is required for a long time, and much time is required for temporarily setting a work scaffold. Therefore, there is a problem that the construction period becomes longer and the construction cost increases.

The present invention has been made in view of the above circumstances, and provides a tank dismantling method capable of shortening the construction period and reducing the construction cost by eliminating the need for work at a high place for a long time and temporary provision of a large-scale work scaffold. The purpose is to do.

[0006]

According to the present invention, a temporary side plate formed in a cylindrical shape having a diameter smaller than the inner diameter of the tank side plate is erected at the bottom of the tank, and the tank side plate is provided around the entire upper end of the temporary side plate. Attach a seal plate that can airtightly slide against the inner peripheral surface,
By introducing pressurized air into the tank to increase the tank internal pressure, the weight of the tank roof and the tank side plate can be supported by air pressure, and then the lower end portion of the tank side plate is placed at a position lower than the upper end of the seal plate. By cutting and removing it, repeating the work of lowering the tank roof and the tank side plate by extracting an appropriate amount of pressurized air in the tank, and after that, most of the tank side plate is dismantled. The present invention relates to a tank dismantling method characterized by performing a dismantling operation of a tank roof landed on the bottom of a tank.

In this way, most of the demolition work can be performed on the ground, so that it is not necessary to perform a long-time high-altitude work or a large-scale temporary work scaffold as in the conventional art.

In addition, the dismantling work of the tank roof, which has been conventionally performed at a high place where workability is poor, can be performed on the ground.

Further, before starting the dismantling work of the tank side plate, a plurality of roof supports taller than the temporary side plates are erected at the bottom of the tank, and the tank roof is attached to the tank bottom through the roof supports. You may make it floor.

With this configuration, the tank roof can be stably landed on the temporary side plate without applying an excessive load.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 7 show an example of an embodiment for carrying out the present invention. In this embodiment, an outer tank 1a and an inner tank 1 are provided.
The case of a tank 1 having a double shell structure composed of b and b is shown, and a tank roof 2 of the tank 1 is constituted by respective roof portions 2a and 2b of an outer tank 1a and an inner tank 1b, and a tank side plate 3 Is the side plate portions 3a, 3 of the outer tank 1a and the inner tank 1b, respectively.
b.

When disassembling the double shell structure tank 1 as described above, the stored liquid and vaporized gas in the tank 1 are first evacuated to an empty state, and then the outer tank 1a and the inner tank 1b.
The suction material such as perlite filled in between is sucked and discharged by a vacuum method. After that, the atmosphere in the tank 1 is replaced with air, and the internal accessories (liquid level gauge, thermometer, Nozzle).

When the dismantling preparation is completed as described above, FIG.
As shown in FIG. 2, the temporary side plate 5 and the seal plate 6 are loaded into the plurality of parts from the carry-in port 4 that is temporarily opened in the lower portion of the tank side plate 3, and as shown in FIGS. Is erected on the tank bottom 7 by welding or the like so as to form a cylindrical shape having a diameter smaller than the inner diameter of the tank side plate 3 (inner diameter of the inner tank 1b), and the tank side plate 3 is provided all around the upper end of the temporary side plate 5.
The seal plate 6 is mounted so as to be capable of airtightly sliding contact with the inner peripheral surface of the inner peripheral surface (the inner peripheral surface of the inner tank 1b).

Here, the seal plate 6 bends when the internal pressure of the tank 1 increases, and the inner peripheral surface of the tank side plate 3 (inner tank 1b).
The inner peripheral surface) of the base plate should be in airtight sliding contact.

At this time, a plurality of roof supports 8 which are taller than the temporary side plates 5 are erected on the tank bottom portion 7 surrounded by the temporary side plates 5, as shown in FIG. Then, it is preferable that the tank roof 2 can be landed on the tank bottom 7 via the roof supports 8.

Next, as shown in FIG. 4, an air introducing pipe 9 is connected to the central portion of the tank roof 2 and the pressurized air 11 is introduced into the tank 1 through the air introducing pipe 9 by the blower 10 so that the tank is 1) The internal pressure is increased so that the weight of the tank roof 2 and the tank side plate 3 can be supported by air pressure.

In such a state, as shown in FIG.
The tank 1 is constructed by closing the air introducing pipe 9 with a valve 12.
After sealing the inside, the lower end portion of the tank side plate 3 is cut and removed at a position lower than the upper end of the seal plate 6.

In this embodiment, since the tank 1 is composed of the outer tank 1a and the inner tank 1b, the outer tank 1a and the inner tank 1b are cut before the lower end of the tank side plate 3 is cut. Of course, the respective roof portions 2a and 2b are integrally connected by a connecting member (not shown).

Further, when the lower end portion of the tank side plate 3 is cut and removed, as shown in FIG. 6, the valve 12 of the air introducing pipe 9 is opened and the pressurized air 11 in the tank 1 is evacuated by an appropriate amount. The tank roof 2 and the tank side plate 3 are lowered, and thereafter, a new lower end portion of the tank side plate 3 is cut and removed, and the pressurized air 11 in the tank 1 is removed.
Is repeated to lower the tank roof 2 and the tank side plate 3 by an appropriate amount.

In this way, when the dismantling of the tank side plate 3 is advanced from the lower end portion, the tank roof 2 comes into a state of landing on the tank bottom portion 7 via the roof support 8 as shown in FIG. The tank roof 2 landed on the tank bottom 7
As for the above, the dismantling work may be advanced on the ground, and the dismantling work of the tank 1 is completed by dismantling the tank roof 2.

Therefore, according to the above-described embodiment, most of the dismantling work can be performed on the ground, so that it is not necessary to perform a work for a long time at a high place or a temporary construction of a large work scaffold as in the conventional case. Thus, it is possible to shorten the construction period and the construction cost.

Further, the tank roof 2 can be dismantled efficiently and safely because the tank roof 2 can be dismantled on the ground, which has been conventionally performed at a high place where workability is poor.

Further, as in the present embodiment, before starting the dismantling work of the tank side plate 3, a plurality of roof supports 8 which are taller than the temporary side plates 5 are erected on the tank bottom 7 and the tank roof 2 is fixed. If the tank bottom 7 is landed via the roof supports 8, the tank roof 2 can be stably landed without applying an excessive load to the temporary side plate 5.

The method of dismantling the tank of the present invention is not limited to the above-mentioned embodiment, and a tank having a double shell structure is illustrated in the figure, but it is also applicable to a tank having a single shell structure. It goes without saying that various changes can be made without departing from the scope of the present invention.

[0026]

According to the tank dismantling method of the present invention described above, various excellent effects as described below can be obtained.

(I) Since most of the dismantling work can be performed on the ground, it is possible to eliminate the work for a long time at a high place and the temporary provision of a large-scale work scaffold as in the conventional art, thereby shortening the construction period. And the construction cost can be reduced.

(II) The tank roof can be disassembled efficiently and safely because the tank roof dismantling work, which was conventionally performed in a high place where workability is poor, can be performed on the ground.

(III) Before starting the dismantling work of the tank side plates, a plurality of roof supports taller than the temporary side plates are provided upright on the tank bottom, and the tank roof is attached to the tank bottom through the roof supports. By landing the tank roof, it is possible to stably land the tank roof without applying an excessive load to the temporary side plate.

[Brief description of drawings]

FIG. 1 is a schematic view showing a carried-in state of a temporary side plate and a seal plate in an embodiment of the present invention.

FIG. 2 is a schematic view showing a state in which the temporary side plate and the seal plate of FIG. 1 are assembled.

FIG. 3 is a perspective view of a temporary side plate and a seal plate of FIG.

FIG. 4 is a schematic view showing a state where pressurized air is being introduced into the tank of FIG.

5 is a schematic view showing a state in which the lower end portion of the tank side plate of FIG. 4 is cut and removed.

FIG. 6 is a schematic view showing a state where the tank roof and the tank side plate of FIG. 5 are lowered.

FIG. 7 is a schematic view showing a state where the tank roof of FIG. 6 is landed on the bottom of the tank.

[Explanation of symbols]

 1 Tank 2 Tank Roof 3 Tank Side Plate 5 Temporary Side Plate 6 Seal Plate 7 Tank Bottom 8 Roof Support 11 Pressurized Air

Claims (2)

[Claims] 1. A temporary side plate formed in a cylindrical shape having a diameter smaller than the inner diameter of the tank side plate is erected on the bottom of the tank, and the entire upper end of the temporary side plate is in airtight sliding contact with the inner peripheral surface of the tank side plate. A sealing plate is installed, and pressurized air is introduced into the tank to increase the tank internal pressure so that the weight of the tank roof and the tank side plate can be supported by the air pressure. Then, the lower end portion of the tank side plate is sealed with the seal. While cutting and removing at a position lower than the upper end of the plate, repeating the work of lowering the tank roof and the tank side plate by extracting an appropriate amount of pressurized air in the tank, and after that,
A tank dismantling method, characterized in that the tank roof on the bottom of the tank is dismantled by dismantling most of the tank side plates. 2. Before starting the dismantling work of the tank side plate,
The tank dismantling method according to claim 1, wherein a plurality of roof supports taller than the temporary side plates are provided upright on the tank bottom, and the tank roof is landed on the tank bottom through the roof supports. .