JPH10212835A - Tank demolition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for high place working for a long period of time and large scaled temporary working scaffold and to provide a demolition method capable of reducing a construction period as well as a construction cost. SOLUTION: A plurality of places in the circumferential direction in the upper end part of a tank side plate 2 are cut in the vertical direction to make breaks 7, the breaks 7 are meandered so as to direct downward while repeating approach and separation of them each other by branching them into right and left from the lower ends of them to extend in phase, and the tank side plate 2 between the breaks 7 and 7 is cut down as a cutting piece 10 made so as to continue a widening section 8 and a narrowing section 9 alternately in the vertical direction. The cutting piece 10 is bent with dead load to fall down in the narrowing section 9 whenever the narrowing section 9 is formed, and the front end part is cut off finely by ground working to widthdraw whenever the front end part of the cutting piece 10 falling downward reaches the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tank dismantling method.

[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, when such a tank is dismantled, a large-scale work scaffold is temporarily provided around the tank, and by using the work scaffold, an operator sequentially uses a burner to sequentially increase the size of the tank from the upper structure of the tank. , And the work of hanging it on the ground with a large crane was repeated.

[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 long-time high-place work and temporary installation of a large-scale work scaffold. It is intended to be.

[0006]

According to the present invention, a plurality of circumferential portions at an upper end portion of a tank side plate are cut in the longitudinal direction to form cuts, and the cut ends are branched right and left to alternately move close to and away from each other. Cut the tank side plate between each cut as a cut piece in which the widened part and the narrow part are alternately continued in the vertical direction by gradually twisting and bending the cut so that it goes downward while repeating At the same time, each time the narrowed portion is formed, the cut piece is bent by its own weight at the narrow portion and falls down, and each time the tip portion of each cut piece that falls down reaches the ground, the tip portion is grounded. The present invention relates to a tank dismantling method characterized in that the work is finely cut and removed by work.

[0007] In this case, the tank side plate is cut and extended as a plurality of cut pieces by simply cutting and extending the tank side plate using an aerial work vehicle or the like, and the tip portion is finely ground by ground work. Since it is possible to cut and remove the tank, it is not necessary to cut the tank side plate finely in a high place where workability is poor as in the past and hang it down on the ground with a large crane In addition, temporary installation of a large-scale work scaffold becomes unnecessary.

[0008]

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

FIGS. 1 to 9 show an embodiment of the present invention. In the drawings, reference numeral 1 denotes a tank to be dismantled, and the drawing shows a case of a floating roof type tank.

As shown in FIG. 1, in this type of tank 1, the body of the tank 1 is formed in a cylindrical shape by a tank side plate 2, and the roof portion of the tank 1 is formed by the tank side plate 2
The floating roof 4 floats on the liquid surface of the storage liquid 3 by sliding around the inner peripheral surface of the storage liquid 3 so as to be able to move up and down.

When the floating roof type tank 1 is dismantled, the storage liquid 3 in the tank 1 is first drawn out to make it empty, and the floating roof 4 which has descended to the bottom of the tank 1 is cut finely. And remove it outside tank 1.

When the tank side plate 2 is ready for disassembly in this way, as shown in FIG. A plurality of extending scribe lines 6 are entered, and the tank side plate 2 is cut along each of the scribe lines 6 as described in detail below.

As shown in FIG. 3, a plurality of circumferential locations at the upper end portion of the tank side plate 2 are vertically cut by a gas cutter or the like using an aerial work vehicle 5, and cuts 7 are formed. As shown in FIG. 4, cutting is performed so that the lower end of each of the cuts 7 branches left and right to extend in the horizontal direction, and each cut 7 is bent downward and extended in the vertical direction in the vicinity of the adjacent cut 7. Cut to make.

When cutting is performed in this manner, the tank side plate 2 between the cuts 7, 7 is a cut piece in which a wide portion 8 having a large width and a narrow portion 9 having a small width are connected in the longitudinal direction. As shown in FIGS. 5 and 6, the cut piece 10 is bent by its own weight at the narrow-width portion 9 having low rigidity and falls into the inside of the tank 1 as shown in FIGS.

However, the cut piece 10 cut out first is in an upright state, and the weight of the cut piece 10 does not contribute to the inside of the tank 1 at all. It is preferable to use a wire rope or the like for auxiliary pulling. In this case, as long as the cutting piece 10 is tilted down to a certain inclination angle, the cutting piece 10 can be tilted down only by its own weight.

Next, as shown in FIG. 7, cutting is performed along the score line 6 from the base end portion of the narrow portion 9 of each cut piece 10 which has been fallen into the inside of the tank 1, and the cut 7 is separated to the left and right again. When each of the cuts 7 is bent downward and extended in the vertical direction in the vicinity of the adjacent cut 7, the tank remaining between the narrow portions 9 of the cut pieces 10 that have fallen in advance is left. Since the side plate 2 is cut out as the widened portion 8 of the cut piece 10 to be turned down next, as shown in FIG. 8, the cut piece 10 is bent by its own weight at the narrow rigid portion 9 having low rigidity, and the tank 1 is bent. Depress inward.

At this time, it is also possible to use a wire rope or the like to assist the towing from the bottom of the tank 1 as needed.

Thereafter, a pair of cuts 7, 7 which are branched from the cuts 7 initially formed in the upper end portion of the tank side plate 2 and extend downward, are alternately repeated close to and separated from each other in the downward direction as described above. What is necessary is just to make twists and turns so as to head and extend it step by step. In this way, each break 7,
The tank side plate 2 between 7 is cut out as cut pieces 10 in which the widened portions 8 and the narrow width portions 9 are alternately continued in the vertical direction, and each cut piece 10 is formed with the narrow width portion 9. Each time it is bent by its own weight at the narrow portion 9 and falls down inside the tank 1.

Generally, since the tank side plate 2 is made of a ductile material, it is relatively easy to bend the narrow portion 9, and the narrow portion 9 is bent by the weight of the cut piece 10. Even if the rigidity is reduced to the degree of bending, there is almost no possibility that the cut piece 10 will be broken by its weight.

As the cutting operation of the tank side plate 2 is continued in this manner, each of the cut pieces 10 falling down into the tank 1
As shown in FIG. 9, each time the tip of each cut piece 10 reaches the bottom of the tank 1, the tip of each cut piece 10 is lowered to the bottom (ground) of the tank 1. The work of finely cutting and removing with a gas cutting machine or the like is repeated by the work, and the tank side plate 2 is entirely cut out as cut pieces 10 and finely cut and removed by ground work, thereby completing the dismantling work of the tank 1.

Therefore, according to the above embodiment, the aerial work vehicle 5
It is possible to cut out the tank side plate 2 as a plurality of cut pieces 10, drop it down, and finely cut and remove the tip portion by ground work, simply by making a cut 7 in the tank side plate 2 and extending using Since it is not necessary to cut the tank side plate 2 finely in a high place where workability is poor as in the related art and suspend the tank side plate 2 on the ground with a large crane, it is necessary to perform a long time in a high place or a large work platform. It is possible to disassemble the tank side plate 2 efficiently and safely without the necessity of temporary installation, thereby shortening the construction period and reducing the construction cost.

Incidentally, the tank dismantling method of the present invention is not limited to the above-described embodiment, and the case of a floating roof type tank is illustrated in the figure, but the tank roof is joined to the upper end of the tank side plate. In the case of tanks that can be used, it can be applied after the tank roof is lowered to the tank bottom by the air-raising method and dismantled.In the illustration, vertical and horizontal lines are cranked to facilitate cutting work Although the case where a continuous cut is formed is illustrated, for example, it is also possible to make a break meandering in a waveform, or to make a continuous cut in a diagonal line inclined in the opposite direction alternately in a zigzag shape. Of course, various changes can be made without departing from the spirit of the present invention.

[0023]

According to the tank disassembly method of the present invention described above, the tank side plate is cut out as a plurality of cut pieces, and the tank side plate is turned down simply by cutting and extending the tank side plate using an aerial work vehicle or the like. It is possible to cut the tip part finely by ground work and remove it, making it unnecessary to cut the tank side plate finely at a high place where workability is difficult as before and drop it on the ground with a large crane. As a result, the tank side plate can be dismantled efficiently and safely without the need for long-time high-place work or temporary installation of a large-scale work scaffold, and the excellent effect of shortening the construction period and reducing the cost can be achieved. obtain.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a floating roof type tank.

FIG. 2 is a front view showing a state where a score line is drawn on the outer peripheral surface of the tank.

FIG. 3 is a front view showing a state where a cut is made in a vertical direction at an upper end portion of the tank.

FIG. 4 is a front view showing a state where cut pieces are cut out.

FIG. 5 is a front view showing a state in which the cut pieces of FIG. 4 are fallen into the inside of a tank.

6 is a view in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is a front view showing a state where a cut piece to be folded down is cut out.

FIG. 8 is a front view showing a state in which the cut pieces of FIG. 7 are folded inside a tank.

FIG. 9 is a perspective view showing a state in which the tip of the cut piece that has reached the ground is being cut.

[Explanation of symbols]

 2 Tank side plate 7 Break 8 Wide part 9 Narrow part 10 Cut piece

Claims (1)

[Claims] 1. A cut is made by cutting a plurality of circumferential portions at an upper end portion of a tank side plate in a longitudinal direction to form cuts, branching from the lower end of each cut to the left and right, and repeating the approach and separation alternately so as to go downward. And the tank side plate between the cuts is cut out as cut pieces in which the widened portion and the narrow portion alternate alternately in the vertical direction, and each cut piece is narrowed. Each time the width portion is formed, the narrow portion is bent by its own weight and falls down, and each time the tip portion of each cut piece that falls down reaches the ground, the tip portion is finely cut by ground work and removed. A tank dismantling method characterized by the following.