JPS63111398A - Method of building inner tank in low temperature storage tank having outer concrete tank - Google Patents

Abstract

PURPOSE:To make it possible to provide one side abutment weldment having a high welding quality, by attaching baking metals to embedded fixings which are previously embedded in a concrete wall so as to secure the baking metals to an outer tank. CONSTITUTION:Fittings 11 are previously embedded and secured in the outer edge parts of inner peripheral section and bottom section of the concrete wall 3 of an outer tank 2, at predetermined intervals, corresponding to the groove lines of inner tank members 10 constituting an inner tank 4. Baking metals 12 for one side face abutment weldment are arranged on the side plate 7 of the inner tank 4, spanning between the embedded fittings 11, in a framelike shape corresponding to the groove line formed around the inner tank members 10, and therefore, the backing metal members are welded together so as to joint them integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for constructing an inner tank of an outer concrete cryogenic storage tank used for storing liquefied petroleum gas (LPG) or the like.

[Conventional technology]

For storage of low-temperature liquids such as liquefied petroleum gas (LPG), an outer-concrete low-temperature storage tank is often used, in which an outer tank is made of concrete and an inner tank that serves as a pressure vessel is installed inside the outer tank. many.

In such an outer concrete cryogenic storage tank, for example, the fifth
As shown in the figure, in the case of an underground tank, a hole of a predetermined size is formed in the ground, and a base 1i11 made of insulating concrete is laid at the bottom of the hole. A temporary formwork is installed and concrete is poured into the temporary formwork to form the concrete wall 3 of the outer tank 2.
Then, after removing the temporary formwork, the inner tank 4 is constructed.

In constructing the inner WJ 4, the bottom plate 5 is laid and welded on the foundation 1 through a heat insulating and cold insulating material 6, and then a heat insulating and cold insulating material 6 is placed inside the concrete wall 3, and the side plate 7 of the inner tank 4 is installed inside this.
are arranged and welded together.

Further, in the roof part, a roof plate 8 is attached and fixed to the upper end of the concrete wall 3, and a heat insulating cold insulating material 9 is attached inside.

[Problem that the invention seeks to solve]

When constructing such an outer tank concrete low-temperature storage tank while welding the side plate 7 of the inner tank 4, it may be difficult to weld the work name on the back side of the side plate 7 or install an automatic welding machine. Therefore, welding must be performed from within the inner tank 4.

For this reason, when butt welding is attempted, a backing metal is required, but a small gap is formed where the backing metals intersect, making it difficult to obtain uniform welding quality, and from the standpoint of thermal stress, etc. Although it is disadvantageous, the current situation is that the inner tank 4 is constructed by overlapping the side plates 7 and performing corner welding.

This invention was made in view of the current situation, and is a method for constructing an inner tank of an outer concrete cryogenic storage tank, which allows butt welding from one side, has good welding quality, and has sufficient strength against thermal stress, etc. The purpose is to provide the following.

[Means for solving problems]

In order to achieve the above object, this invention constructs an inner tank inside an outer concrete tank! 5, a plurality of embedded metal fittings are placed in advance in the concrete outer tank corresponding to the groove line of the inner tank material to be welded and joined, and a real butt for single-sided welding is attached via these embedded metal fittings, and This device is characterized in that the backing metals are joined together, and the inner tank material is placed on top of these backing metals and welded together one side.

[Effect]

To enable one-sided butt welding of the inner material, backing metals are placed integrally along the groove line of the inner tank material, but in order to fix these actual metals to the outer tank. An embedded metal fitting is placed in the concrete in advance, and a real abutment is attached to the embedded metal fitting to realize single-sided butt welding with good welding quality.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

The method for constructing the inner tank of the outer tank concrete low-temperature storage tank is to attach the inner tank material 10 constituting the inner tank 4 in advance to the inner periphery of the concrete wall 3 and the outer edge of the bottom of the outer tank 2 shown in FIG. The embedding metal fittings 11 are embedded at regular intervals corresponding to the lead line, and then placed.

As shown in FIG. 1, this embedding tool 11 is, for example, one in which an L-shaped anchor 11b is attached to the P'i portion of a rectangular mounting plate 11a.

Note that the shapes of the mounting plate 11a and the anchor 11b do not have to be rectangular or L-shaped.

As for the side plate 7 of the inner tank 4, as shown in FIG. It has a frame shape corresponding to the groove line, and each of the real dowels 12 is welded and joined together.

In addition, in Figure 1, concrete wall 3 (5th
Although the diagram omits the heat insulating cold insulating material 6 inside the heat insulating material 6 (see figure), if the heat insulating cold insulating material 6 is to be interposed, a metal spacer with a height corresponding to the thickness of the heat insulating material 6 can be used as shown in FIG. 13 is welded and fixed onto the embedded metal fitting 11, and then the backing metal 12 is welded to this metal spacer 13.

On the other hand, at the upper end of the side plate 7 of the inner tank 4, there is provided a seal plate 14 having an annular cross-sectional shape as shown in FIG. The concrete wall 3 is welded to the roof plate 8 at its upper end.

In order to enable single-sided welding between the side plate 7 and the seal plate 14, an angle backing metal 12a corresponding to the shape of the top angle 14 is used, and its connecting portion is also welded to the linear backing metal 12. .

In addition, the joint between the lower end of the side plate 7 of the inner tank 4 and the bottom plate 5 is as follows.
As shown in FIG. 4, welding is performed through the corner angle 15, and a corner backing metal 12b is used at the connection part of the corner angle 15, and a straight backing metal 12 and welded.

In this way, all the backing metals 12. The seal plate backing metal 12a and the corner angle backing metal 12b are welded to the embedded metal fitting 11, and their abutted portions are also welded to form an integrally joined state.

Thereafter, the inner tank 010 is butted against the backing metal 12 or the seal plate 1, the backing metal 12a, and the corner angle backing metal 12b, and one-sided welding is performed from the inside of the inner tank 4.

During this single-sided welding, either the real butting metals 12.12a or 12b are located on all surfaces of the butt U groove, and the backing metals are joined together so that there is no gap between them. High quality welded joints can be obtained.

In addition, on the back side of the joint of the inner tank 4 constructed in this way,
Since the embedded metal fitting 11 is in a state of protruding from the concrete wall 3 by the thickness of the plate, the actual metal fitting 12 (or 1
A gap is formed by the thickness of 2a, 12b) and the embedded metal fitting 11, and if the inspection gas for leakage inspection is injected into this gap, inspection for welding defects can be easily performed. can.

In addition, although the said Example demonstrated the case where it applied to an underground tank, it can also apply to an above-ground tank.

Further, a heat insulating and cold insulating material may be interposed in the seal plate portion and the cone angle portion, and in this case, the actual weight is fixed via a metal spacer as shown in FIG.

〔Effect of the invention〕

As explained above in detail with the actual examples, according to the present invention, an embedded metal fitting is set in the outer tank concrete in advance with a mounting number, and this embedded metal fitting is used to align the groove line of the inner tank material. Correspondingly, real butts were placed and they were joined together to form an integral piece, and then the inner tank materials were butted together on the backing metal and welded on one side, so the inner tank materials could be overlapped like in the past. There is no need for fillet welding, and the strength of the welded joint is high.

In addition, since the backing metals are joined together, welding quality is good and uniform, and unlike conventional methods, welding defects due to gaps between the backing metals do not occur, and stress concentration does not occur. do not have.

Furthermore, the strength of the inner tank is increased because the embedded metal fittings and the real dowel function as reinforcing materials.

Further, since the actual deposit is located on the back side of the inner tank, there is a gap between the outer tank concrete and the inner tank by at least this thickness, which can also be used as a gas flow path for inspecting the welded part.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the method for constructing an inner tank for an outer concrete cryogenic storage tank according to the present invention, with Figure 1 being a perspective view without showing the arrangement of the backing metal, and Figure 2 being an insulating and cold storage tank. 3 is a perspective view of a seal plate portion, FIG. 4 is a perspective view of a corner angle portion, and FIG. 5 is a sectional view of an example of an object to which the present invention is applied. . 1...Foundation, 2...Outer tank, 3...Concrete wall, 4...Inner tank, 5...Bottom plate, 6...Insulating cold insulation material,
7... Side plate, 10... Inner tank material, 11... Embedded metal fitting, 12... Backing metal, 13... Metal spacer, 14...
...Seal plate, 15...Corner angle.

Claims (1)

[Claims] When constructing an inner tank inside an outer concrete tank, multiple embedded fittings are placed in advance in the concrete outer tank corresponding to the groove lines of the inner tank materials to be welded together, and single-sided welding is performed via these embedded fittings. An outer tank concrete low-temperature storage tank characterized in that a backing metal is attached, the backing metals are joined together, and the inner tank material is placed on these backing metals and one-sided butt welded. How to construct an inner tank.