JPS6294581A - Method of overhauling storage tank - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for dismantling a storage tank that stores fluid such as liquefied natural gas or heavy oil and is constructed airtight with the outside.

[Conventional technology]

The side walls and bottom plates of storage tanks that store liquefied natural gas, heavy oil, etc.
From the inside due to sludge and moisture contained in the fluid,
In addition, if the tank is corroded from the outside by salt, sulfur, etc. contained in the outside air, and it is impossible to restore the tank by repairing the corroded parts, it will be necessary to dismantle it and make a new tank entirely.

As shown in Figure 6, one method for dismantling the entire storage tank is to temporarily construct a work scaffold C outside the storage tank a close to the side wall of the storage tank a from the ground level e to the top of the storage tank a. Crawler crane d is placed at e, and workers use work scaffolding C to dismantle the storage tank a from the top to a weight that can be supported by crawler crane d, and temporarily place the dismantled pieces on ground e using crawler crane d. The dismantling of the storage tank is completed.

[Problem that the invention seeks to solve]

However, such conventional disassembly methods have the following problems.

(1) Since high-rise work scaffolding was required outside the storage tank, a large amount of money was required for temporary construction.

(2) Large loading machines such as crawler cranes were required for a long period of time until the demolition was completed, resulting in a large amount of expense.

■ Much of the demolition work was carried out at high places, which was highly dangerous and inefficient.

(Purpose of the Invention) The present invention was devised to effectively solve the problems of the conventional method, and enables the dismantling of storage tanks on the ground without the need for work scaffolding or large multipurpose machinery. The purpose is to provide a method.

[Means to solve the problem]

In order to achieve the above object, the storage tank dismantling method of the present invention includes:
A cylindrical sealing material mounting frame is provided inside the storage tank, the lower end of which is tightly fixed to the bottom plate of the storage tank around the entire circumference, and the upper end of which is located near the inner surface of the side wall of the storage tank, and is slidable on the inner surface of the side wall of the storage tank. A sealing material made of an elastic material that is in close contact with the entire circumference is attached to the upper end of the sealing material mounting frame, and a required position below the position where the sealing material is in close contact with the side wall of the storage tank is cut along the entire circumference to separate an upper part of the storage tank and a lower part of the storage tank. The upper part of the storage tank is floated by supplying compressed air to the inside of the storage tank, the side wall of the lower part of the storage tank is removed, and the pressure of the compressed air inside the storage tank is adjusted. It is characterized in that it is lowered until the lower end of the upper part comes into contact with the bottom plate, and then the side walls of the upper part of the storage tank are successively removed from below in the same manner as described above.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for dismantling a storage tank, which is an embodiment of the present invention, will be described below with reference to the drawings.

FIG. 1 is a sectional view of the storage tank dismantling method of the present invention, FIG. 2 is a top view of the opening, and FIG. 3 is a side view of the storage tank being dismantled.

As shown in FIG. 1, before disassembly, a sealing material mounting frame 4, whose height is slightly higher than the height of the lowermost side plate 2a constituting the side wall 2 of the storage tank 1 and whose diameter expands upward, is installed. , are arranged close to the inside of the side wall 2. The lower end of the sealing material attachment frame 4 is hermetically welded to the bottom plate 3 of the storage tank 1, and the sealing material 5 made of an elastic material and movably attached to the side wall 2 is hermetically attached to the upper part. A blower 17 is provided on the roof 6 of the storage tank 1, and an opening 8 provided in the center of the roof 6 and a discharge port of the blower 7 are connected by a pipe 9. Around the opening 8, as shown in FIG. One end of the wire rows 110 (in the example, three wire rows) are fixed at approximately equal intervals, and the other end is wound two to three times around the winding drum 11 with a brake provided on the ground 14, and then set in a tensioned state and preparation is completed. do.

As shown in FIG. 3, compressed air is fed into the storage tank 1 from the opening 8 through the pipe 9 by the feeder 1!1117, and then the upper end of the lowermost side plate 2a is cut all around. ,
The tank is divided into an upper part 1a and a lower part 1b. After loosening the wire loaf 10 and floating the upper part 1a of the storage tank, remove the side plate 2.
a from the bottom plate 3 and remove it, and then remove the storage tank upper part 1a.
The storage tank 1 is lowered while adjusting the internal pressure until it contacts the upper surface of the bottom plate 3, and after the contact, the wire loaf 10 is wound up on the winding drum 11 and the wire loaf 110 is brought into tension.

The remaining upper part 1a of the storage tank is sequentially cut and removed in the same manner as described above, and after the side wall 2 is removed, the roof 6 and the bottom plate 3 are removed to complete the dismantling of the storage tank 1.

[Examples of odd forms]

The present invention is not limited to the above-mentioned embodiments, and the following modifications can be made within the scope of the claims.

FIGS. 4 and 5 are cross-sectional views of a storage tank being dismantled, showing a modified example.

As shown in FIG. 4, compressed air is supplied into the storage tank 1 from the opening 8 through the pipe 9 by the blower 7, and then the entire circumference of the upper end of the lowermost side plate 21 is cut to remove the upper part of the storage tank. It is divided into 1a and a storage tank lower part 1b. Loosen the wire loaf 10 and float the storage tank upper part 1a to form a gap C at the cutting location,
After inserting at least three pillows 12 into the gap C at approximately equal intervals, the supply of compressed air is stopped, the storage tank upper part 1a is lowered, and the lower end of the side wall 2 is brought into contact with the upper surface of the pillows 12. Side plate block 2 where the storage tank upper part 1a is fixed and the pillow 12 is inserted
1a remaining, the side plate blocks 21b at four locations are cut from the bottom plate 3 and removed. Then, as shown in FIG. 5, the upper part 1a of the storage tank is re-floated, a pedestal 13 is interposed between the bottom plate 3 and the lower end of the side wall 2, and the remaining side plate block 21 is
a is cut and removed, and the storage tank 1 is lowered while adjusting the internal pressure until the upper part 1a of the storage tank comes into contact with the upper surface of the bottom plate 3. After this contact, the wire lobe 10 is wound up on the winding drum 11. The wire row 110 is brought into tension.

The remaining upper part 1a of the storage tank is sequentially cut and removed in the same manner as described above, and after the side wall 2 is removed, the roof 6 and the bottom plate 3 are removed to complete the dismantling of the storage tank 1.

In this way, by inserting the pillow and the pedestal into the cut gap, it is possible to further improve the safety of the work.

It should be noted that the present invention is not limited only to the above-mentioned embodiments, and it goes without saying that various changes may be made without departing from the gist of the present invention.

〔Effect of the invention〕

As explained above, the storage tank dismantling method of the present invention has the following excellent effects.

(1) Since there is no need to temporarily construct high-rise work scaffolding outside the storage tank, it is possible to reduce costs and shorten the construction period.

(2) Since a large loading machine is not required, costs are reduced, a large work area can be secured, and work safety is increased.

(Q: Since demolition work can be carried out on the ground, work efficiency and work safety will increase.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the storage tank dismantling method of the present invention, FIG. 2 is a top view of the opening, FIG. 3 is a sectional view of the storage tank being dismantled, and FIGS. 4 and 5 are cross sections showing modified examples. 6 are cross-sectional views of the conventional method. 1 is a storage tank, 2 is a side wall, 3 is a bottom plate, 4 is a sealing material mounting frame, 5 is a sealing material, 6 is a roof, 7 is a kite sending device, 8 is an opening, 9 is a pipe, 10 is a wire rope, 11 is winding drum,
12 indicates a pillow, and 13 indicates a pedestal.

Claims (1)

[Claims] A cylindrical sealing material mounting frame is provided inside the storage tank, the lower end of which is tightly fixed to the bottom plate of the storage tank around the entire circumference, and the upper end of which is located near the inner surface of the side wall of the storage tank, and is slidable on the inner surface of the side wall of the storage tank. A sealing material made of an elastic material that is in close contact with the entire circumference is attached to the upper end of the sealing material mounting frame, and a predetermined position below the position where the sealing material is in close contact with the side wall of the storage tank is cut across the entire circumference to form the upper part of the storage tank. The storage tank is divided into a lower part and a lower part of the storage tank, and compressed air is supplied to the inside of the storage tank to float the upper part of the storage tank, and then a side wall of the lower part of the storage tank is removed, and then the pressure of the compressed air inside the storage tank is adjusted. A method for dismantling a storage tank, comprising: lowering the upper part of the storage tank until the lower end thereof contacts the bottom plate, and then sequentially removing side walls of the upper part of the storage tank from below in the same manner as described above.