JP2000265705A - Method for installing bottom plate of double shell tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the bottom-plate installing method of a double shell tank, by which an inner-tank bottom plate can be installed without waiting the completion of a roof and without requiring high-place works. SOLUTION: A reinforcing material 13 being lifted and lowered only by elevator materials 12 such as jacks, in which an inner-tank bottom plate 2a assembled on the frame 4 of an outer-tank bottom plate 1a is mounted on an outer circumferential section, and being supported to the intermediate section of an inner-tank side plate 2b while being used for supporting the inner-tank bottom plate 2a only by the outer circumferential section is secured. Accordingly, the inner-tank bottom plate 2a can be installed without waiting the completion of a roof and without requiring high-place works.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing a bottom plate of a double shell tank, and can easily install the bottom plate of an inner tank without using a side plate of an inner tank without waiting for installation of a roof. It is like that.

[0002]

2. Description of the Related Art In a low-temperature storage tank such as a ground-type LNG tank,
For example, as shown in FIG. 3, a double shell tank composed of an outer tank 1 and an inner tank 2 is provided, and a cooling layer 3 is provided between the inner and outer tanks so as to minimize heat entering from the outside.

In such a double-shell tank, the inner tank 2 which is in contact with the low-temperature liquid is made of a low-temperature material, and the inner tank bottom plate 2a
Are manufactured by butt welding.

[0004] For this reason, the installation of the inner tank bottom plate 2a of the double shell tank is performed in the following steps, for example.

First, the outer tank bottom plate 1a is placed on the foundation concrete.
After assembling, the outer tank side plate 1b and the inner tank side plate 2b are assembled, and the inner and outer tank roofs 1c, 2c are assembled at adjacent places. Then, the inner tank bottom plate 2a is assembled by butt welding on the assembled outer tank bottom plate 1a via the gantry 4.

Thereafter, the inner and outer tank roofs 1 assembled at adjacent locations on the outer tank side plate 1b and the inner tank side plate 2b that have been assembled are completed.
c, 2c are attached.

After the inner and outer tank roofs 1c and 2c are attached in this way, as shown in FIG. 4, the roof 2c and the inner tank side plate 2b are mounted.
Utilizing the knuckle portion 2d at the upper end, a plurality of locations (for example, eight locations) in the radial direction of the inner tank bottom plate 2a and a plurality of locations in the circumferential direction (for example, one location at the center and 15 locations on its outer circumference, and further on the outer circumference, respectively) 45 locations (for example, a total of 2 locations)
(86 locations), the wire and the chain block 5 are attached, and reinforcement is performed so that the inner tank bottom plate 2a can be lifted integrally.

After connecting the inner tank bottom plate 2a and the roof 2c or the inner tank bottom plate 2a and the knuckle portion 2d with a number of wires and chain blocks 5, the inner tank bottom plate 2a
a, the gantry is removed, the inner tank bottom plate 2a is lowered and installed at a predetermined position, and the wire and the chain block 5 are removed.

[0009]

However, in such a method of mounting the inner tank bottom plate, a wire and a chain block 5 are attached to a large number of places in order to raise and lower the inner tank bottom plate 2a integrally, and to attach them to the knuckle portion 2d. And the roof 2c, there is a problem that the installation work of the inner tank bottom plate 2a can be performed only after the roofs 1c, 2c are completed.

In addition, since the wire and the chain block 5 are supported by the knuckle portion 2d and the roof 2c, there is a problem that these mounting operations are performed at a high place, which is not preferable in terms of safety.

The present invention has been made in order to solve the problems of the prior art, and has a double shell tank capable of installing an inner tank bottom plate without waiting for completion of a roof and without requiring work at a high place. It is intended to provide a method for installing a bottom plate.

[0012]

In order to solve the problems of the prior art, a method for installing a bottom plate of a double shell tank according to the first aspect of the present invention comprises the steps of: After assembling the tank bottom plate, assembling the outer tank side plate and the inner tank side plate, assembling the inner tank bottom plate via the gantry on the outer tank bottom plate, attaching a reinforcing material to the assembled inner tank bottom plate, and ascending and descending integrally. As well as, the periphery of the inner tank bottom plate can be raised and lowered with lifting equipment attached to the inner tank side plate, the inner tank bottom plate is raised with the lifting equipment and the gantry is removed, and then lowered to lower the inner tank bottom plate. It is characterized in that it is installed, and the reinforcing material and the lifting equipment are removed.

According to the method for installing the bottom plate of the double shell tank, the inner bottom plate assembled on the outer bottom plate is moved up and down only by a lifting device such as a jack attached to the outer peripheral portion, so that the inner bottom plate is placed halfway along the inner bottom plate. Along with supporting the inner tank bottom plate, a reinforcing material is attached so that it can be supported only at the outer periphery, so that the inner tank bottom plate can be installed without waiting for the completion of the roof and without requiring work at height Become like

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 and 2 relate to an embodiment of a method for installing a bottom plate of a double-shell tank according to the present invention. FIG. 1 is a schematic perspective view, and FIG. 2 is a process diagram.

The method of installing the bottom plate of the double-shell tank is applied to the inner tank bottom plate 2a of the above-ground double-shell tank, and can be installed using the inner tank side plate 2b irrespective of the installation of the roof. .

In this double-shell tank, first, an outer tank bottom plate 1a is assembled on basic concrete, an outer tank side plate 1b is assembled on the outer periphery thereof, and an annular bottom plate 1a is formed on the outer layer bottom plate 1a inside the outer tank side plate 1b. The inner tank side plate 2b is assembled via the inner tank annular plate 2e.

In parallel with the assembly of the inner and outer tank side plates 1b and 2b, the inner tank bottom plate 1a is assembled by butt welding on the outer tank bottom plate 1a via the gantry 4 (see FIG. 2 (a)).

In addition to assembling the inner / outer tank side plates 1b, 2b and the inner tank bottom plate 1a, the inner / outer tank roof 1
Assembly of c and 2c is performed.

After the assembly of the inner tank bottom plate 2a is completed, the side plate bracket 1 is attached to the inner tank side plate 1b for installation.
1, jacks 12 as lifting equipment are installed at regular intervals in the circumferential direction so that the inner tank bottom plate 2a can be raised and lowered.
For example, jacks 12 are respectively installed at 45 locations on the circumference.

The inner tank bottom plate 2 is formed only by the outer peripheral jack 12.
a, the strength of the inner tank bottom plate 2a is insufficient and the inner tank bottom plate 2a cannot be lifted and lowered together.
The reinforcing material 13 is mounted on the support member a, and is supported at a large number of positions in the radial direction and the circumferential direction (for example, a total of 286 positions) in the same manner as the case where the reinforcing material 13 is suspended and suspended by a conventional wire and chain block.

Therefore, as the reinforcing member 13, for example, FIG.
As shown in the figure, the support members 13a radially arranged at regular intervals in the circumferential direction using a hollow steel material are connected by a reinforcing member 13b in the radial direction, the circumferential direction, and further in the oblique direction to form a frame structure, and the support member 13a Bracket 1 attached to the lower surface
3c is connected to the inner tank bottom plate 2a by welding. Then, the number of the brackets 13c is set to be the same as the number of the hanging points by the conventional wire, and the strength that the inner tank bottom plate 2a can be lifted and hung only by the outer peripheral jack 12 is secured (see FIG. 2B).

Next, the inner tank bottom plate 2a is raised by operating each jack 12, and the gantry 4 installed for butt welding is removed (see FIG. 2 (c)).

Then, a bottom heat insulating layer is provided on the outer bottom plate 1a by a perlite concrete block or the like.

Thereafter, each jack 12 is operated to lower the inner tank bottom plate 2a together with the reinforcing material 13 and set and installed on the bottom heat insulating layer (see FIG. 2 (d)).

After the installation by the lowering of the inner tank bottom plate 2a is completed, the reinforcing member 13 and the jack 12 are removed (see FIG. 2E).

Thereafter, the outer periphery of the inner tank bottom plate 2a and the inner tank annular plate 2e are welded to complete the inner tank bottom plate 2a.

As described above, the inner tank bottom plate 2a is raised and lowered by the jack 12 using the inner tank side plate 2b, and the insufficient strength for suspending the inner tank bottom plate 2a is compensated for by attaching the reinforcing material 13. As a result, the inner tank bottom plate 2a can be installed without waiting for installation of the roof as in the related art.

Thus, it is not necessary to install the inner tank bottom plate 2a as a final step, and the construction period of the double shell tank can be greatly reduced.

Further, since the supporting point of the elevating equipment (in this case, the jack 12) for raising and lowering the inner tank bottom plate 2a is set to the inner tank side plate 2b and the intermediate portion, the conventional roof or knuckle portion is used as the supporting point. Work at high places is eliminated compared to the case where
The cost can be reduced without the necessity of temporary installation of a scaffold.

Although the jack is used as the lifting device, the invention is not limited to this, and other lifting devices such as a chain block may be used.

Also, the connection between the reinforcing member and the inner tank bottom plate has been described in the case where one bracket is used to weld each other. However, there is a case where one bracket cannot be used for welding depending on the material of each material. Welding,
These may be connected via a wire, a bolt, or the like.

[0032]

According to the method for installing the bottom plate of the double-shell tank according to the first aspect of the present invention, the bottom plate of the inner tank of the double-shell tank is installed as specifically described above with reference to one embodiment. At this time, after assembling the outer tank bottom plate, assembling the outer tank side plate and the inner tank side plate, assembling the inner tank bottom plate via a gantry on the outer tank bottom plate, attaching reinforcing material to the assembled inner tank bottom plate and integrating To be able to go up and down
The periphery of the inner tank bottom plate can be moved up and down by lifting equipment attached to the inner tank side plate, the inner tank bottom plate is raised with the lifting equipment and the gantry is removed, and then lowered to install the inner tank bottom plate,
As we removed the reinforcement and lifting equipment,
The inner tank bottom plate assembled on the outer tank bottom plate can be supported in the middle of the inner tank side plate with lifting equipment such as jacks attached to the outer periphery, and can be supported only at the outer periphery with the reinforcement attached to the inner tank bottom plate The strength can be ensured, and the inner tank bottom plate can be installed without waiting for the completion of the roof and without work at height.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an embodiment of a method for installing a bottom plate of a double shell tank according to the present invention.

FIG. 2 is a process chart according to an embodiment of a method of installing a bottom plate of a double shell tank according to the present invention.

FIG. 3 is a sectional view showing a right half of a double shell tank to which the present invention is applied;

FIG. 4 is an explanatory view of a conventional method of installing an inner tank bottom plate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outer tank 1a outer layer bottom plate 1b outer tank side plate 1c outer layer roof 2 inner tank 2a inner layer bottom plate 2b inner tank side plate 2c inner layer roof 2d knuckle part 2e inner tank annular plate 3 cold insulation layer 4 gantry 11 side plate bracket 12 jack 13 reinforcing material 13a support Member 13b Reinforcement member 13c Bracket

Claims (1)

[Claims] When the inner tank bottom plate of the double shell tank is installed, after assembling the outer tank bottom plate, the outer tank side plate and the inner tank side plate are assembled, and the inner tank bottom plate is mounted on the outer tank bottom plate via a gantry. After assembling, the reinforcing material is attached to the inner tank bottom plate after assembly so that the inner tank bottom plate can be moved up and down integrally, and the periphery of the inner tank bottom plate can be moved up and down by the lifting equipment attached to the inner tank side plate. And removing the gantry by lowering the gantry, lowering the gantry and installing the inner tank bottom plate, and removing the reinforcing material and the lifting / lowering equipment, wherein the bottom plate of the double shell tank is removed.