JPH044398A - How to build an underground 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] [Industrial Application Field] The present invention relates to a method of constructing an underground tank in which a membrane is formed via a cold insulation layer on the inner wall of a concrete tank body serving as an outer tank of a low-temperature tank. In particular, the present invention relates to a method of constructing an underground tank in which a concrete panel having a membrane is separately formed in a factory or the like and is attached to the inner wall of a concrete tank body.

[Prior art] A method of constructing an underground tank for storing low-temperature liquids such as LNG and LPG is to form a cylindrical concrete tank body with a bottom underground, and assemble a tank roof at the bottom of the tank body. After the roof is raised and installed by near-raising, membrane panels are attached to the inner wall of the concrete tank body via a cold insulation layer, and the panels are welded together to form an inner tank that essentially accommodates the low-temperature storage liquid. It has been known.

[Problems to be Solved by the Invention] By the way, the work inside the tank involves cold insulation work and membrane panel installation (=1 - welding work) in the form of parallel work.In this case, the side part of the concrete tank body Work on the inner walls is inefficient because workers must ride on gondolas.At the bottom of the concrete tank, the material is temporarily placed when installing the side inner walls, so the membrane panels on the side inner walls are difficult to install. Cold insulation work and membrane panel installation/welding work cannot begin until the installation work is completed.In order to shorten the construction period of the underground tank, the roof installation is necessary for the series of work inside the tank later. It is necessary to shorten the time. Therefore, it is desirable to form individual membrane panels in a large size and to reduce the number of seal welding points between adjacent membrane panels as much as possible to improve workability. However, in general, The membrane panel is thin enough to be press-formed with corrugations that allow thermal expansion and contraction, so it is easily deformed and cannot be expected to be significantly larger.

The present invention was created to solve the above problems,
The purpose is to provide a method for constructing an underground tank that shortens the construction period and is highly reliable.

[Means for Solving the Problems] In order to achieve the above object, the present invention constructs a bottomed cylindrical concrete tank underground, and then stores a low-temperature storage liquid on the inner wall of the concrete tank. In a method for constructing an underground tank forming a membrane, a membrane panel is integrally formed on a concrete panel divided into predetermined sizes to cover the inner wall of the concrete tank body with a cold insulation layer interposed therebetween; is attached to the inner wall of a cylindrical concrete tank with a bottom underground.

[Function 1] Concrete panels 1 to 1 having a membrane panel and a cold insulation layer are separately formed in a factory or the like, and the concrete panels are attached to the inner wall of a concrete tank at the site, and the adjacent membrane panels are seal-welded.

Since a cold insulation layer is formed in advance between the concrete panel and the membrane panel, the cold insulation work inside the tank can be reduced. By setting the dimensions of the concrete panel as large as possible, the membrane panel integrally formed therewith via the cold insulation layer can also be formed large, so the number of seal welding points between adjacent membrane panels can be reduced. Since the process of forming a cold insulation layer on a concrete panel and integrally forming a membrane panel via the cold insulation layer can be performed in a factory or the like, a product of good quality can be obtained.

Therefore, the construction period can be significantly shortened and reliability can also be improved.

[Example] Next, one embodiment of the present invention will be described.

In FIG. 1, reference numeral 1 denotes a bottomed cylindrical concrete tank body constituting the outer tank of the underground tank. The side inner wall 2 of the concrete tank body 1 has a 48-sided wall surface so that its cross-sectional shape is a regular 48-sided square. Inside the concrete tank body 1, a side panel 4 is provided on the side inner wall 2, and a bottom panel 5 is provided on the bottom inner wall 3 to form a cold insulation layer and an interior structure (membrane) that substantially accommodates the low-temperature storage liquid. Can be installed respectively.

As shown in FIGS. 2(a) to 2(c), the side panel 4 includes a heat insulating layer 7 formed on the front surface of a rectangular concrete panel 6, and a membrane panel 8 integrated with the heat insulating layer 7. It is mainly configured by being attached to. The concrete panel 6 has a width set to one span that divides the inner circumference of the side inner wall 2 into 48, and a vertical width set to one span that divides the inner circumference of the side inner wall 2 into three in the height direction. The membrane panel 8 is constructed by welding and connecting pieces 8a having corrugations 9 that allow thermal expansion and contraction, and is formed so that the vicinity of the peripheral edge 7a of the surface of the heat insulating layer 7 is slightly exposed. On the back side of the concrete panel 6,
Mounting fittings 1o for attaching the concrete panel 6 to the side inner wall 2 are provided at three upper and lower locations, as shown in FIG. 2(b). As the mounting bracket 10, a T-shaped steel cut to a predetermined length is used as shown in FIG.
One end flange part 10a of the H-shaped steel is attached to the concrete panel 6.
The other end flange portion 10b is embedded within the panel 6 and firmly fixed so as to protrude from the back surface of the panel 6. On the other hand, in the side inner wall 2 of the concrete tank body 1, a slanted guide hole 11 that engages with the mounting bracket 10 to hold the side panel 4 in a predetermined position on the side inner wall 2 is provided to form a 48-sided wall surface. They are formed at appropriate intervals on the center line of each constituent surface. The kite hole 11 is inserted into the flange portion 10 of the mounting bracket 10 by inserting the mounting bracket 10 from above and moving it downward.
The side panel 4 is configured to be firmly engaged with the side panel a to hold the side panel 4 in a predetermined position on the side inner wall 2.

Inside the concrete panel 6, there is a side panel 4 which is held on the side inner wall 2 by engaging the mounting bracket 10 with the guide hole 11.
A pair of fixing devices 12 are provided in the vicinity of both ends for tightly fixing the to the side inner wall 2. On the other hand, the side inner wall 2
is provided with an engagement pin 13 that engages with the fixing device 12. The engagement pin 13 is 11!11 as shown in FIG.
The fixing bracket 15 is embedded in the inner wall 2 of the side part along the height direction, and has openings 15a buried in the inner wall 2 of the side part along the height direction at predetermined intervals. The fixing device 1 is installed inside the fixing bracket 15.
It forms an engaging portion 13a with 2.

As shown in FIG. 2C and FIG. 6, the fixing device 12 has an operating shaft 33 that is rotatably embedded in the concrete panel 6 and extends from the upper end of the panel 6 to near the lower end thereof, and the operating shaft 33 that is fixed to the operating shaft 33 and engaged with the above. It is mainly composed of a hook member 14 that engages with the portion 13a.

The hook member 14 is housed in a hook hole 16 opened on the back side of the concrete panel 6, and is configured such that it rotates by rotating an operating shaft 33 so that its tip comes out and disappears from the hook hole 16. . The fixing device 12 is the sixth
As shown in the figure, a rotating handle 17 is provided at the upper end of the operating shaft 33, and by rotating the rotating handle 17 in the direction of arrow A, the hook member 14 is engaged with the engagement pin 13 and locked. The structure is such that the side panel 4 can be fixed in close contact with the side inner wall 2. On the lower surface of the concrete panels 1 to 6, there is a rotating handle of the lower panel 4 when the side panel 4 is vertically attached to the side inner wall 2, as shown in FIGS. 2(b) and 2(c). A recess 18 for accommodating the recess 17 is formed.

Among the side panels 4 formed in this way, the side panel 4L disposed at the bottom has one tapered thick wall portion at the lower end of the concrete panel 6L, as shown in FIG.
The cold insulation layer 7 and the membrane panel 8 are bent to match the shape.

As shown in FIGS. 1 and 3(a) to (c), the bottom panel 5 is formed into a substantially fan shape that divides the bottom side wall 2 into 48 parts in the circumferential direction and into an inside part and an outside part, and is made of concrete. Mainly, a cold insulation layer 21 is formed on the upper surface of the panel 20, and a membrane panel 22 is integrally attached via a heat insulating material layer 21. Membrane panel 2
2 is constructed by welding and connecting a plurality of pieces 22a having corrugations 9 that allow thermal expansion and contraction, as shown in FIG. It is formed in such a way that it

As shown in FIG. 3(c), the bottom panel 5 is provided with casters 23 near its four corners. The caster 23 is
As shown in FIG. 7, a shaft portion 27 of a caster member 25 having a wheel 24 whose neck can freely vibrate is screwed into a screw hole 26a of the support plate 26° buried in the concrete 1-panel 20. It consists of The caster member 25 has a screw thread formed on the side surface of the shaft portion 27 and a nut portion 28 formed at the upper end.The caster member 25 can be rotated up and down with respect to the support plate 26 by gripping and rotating the nut portion 28 with a spanner or the like. Configured to move.

The caster 23 configured in this manner is provided so that the shaft portion 27 penetrates the concrete panel 20, as shown in FIG. 3(b). concrete panel 20
A wheel accommodating portion 29 is opened at the position where the caster 23 is attached on the back side of the concrete panel 20 so that the wheel 24 can be completely accommodated in the panel 20 when the caster member 25 is moved upward with respect to the concrete panel 20. There is. Cutouts 32 are formed on both sides of the cold insulation layer 21 to expose the nut portions 28 of the caster members 25. Caster 23
supports the lower panel 5 so that it can run freely when the wheels 24 are protruded below the concrete panel 20,
The lower panel 5 is configured to be seated on the bottom inner wall 3 of the tank body 1 when the vehicle va24 is accommodated in the wheel accommodating portion 29. Positioning protrusions 30 are formed on the lower surface of the concrete panel 20 at three locations on the center line, and on the other hand, positioning holes 31' are formed on the bottom inner wall 3 into which these protrusions 3o are fitted. The bottom panel 5 is seated on the bottom inner wall 3'' by fitting the convex portion 30 into the positioning hole 31, so that the bottom inner wall 3 can be easily positioned at a predetermined position. This prevents the seat from moving after being seated.

Next, a method for constructing an underground tank will be explained.

After forming a bottomed cylindrical concrete tank body 1 underground, a tank roof (not shown) is assembled at the bottom of the tank body, and the assembled roof is raised by near raising and installed. After the roof is installed, a part of the roof is opened to form a construction opening for carrying in the side panels 4 and the lower panel 5.

The side panel 4 and the bottom panel 5 are manufactured separately in a factory or the like and transported to the construction site of the underground tank. The side and bottom panels 4.5 transported to the construction site are carried into the tank by a large crane.

First, the side panel 4 is carried into the tank and the side inner wall 2
can be attached to. The side panels 4 are attached sequentially starting from the lower panel 4. Positioning of the side panel 4 with respect to the side inner wall 2 can be easily achieved by engaging the mounting bracket 10 provided thereon with the guide hole 11, and fixation is achieved by engaging the engagement pin 13 with the hook member 14 of the fixing device 12. This can be easily achieved by rotating the rotating handle 17 so as to lock it. After attaching the side panel 4 to the side inner wall 2, a membrane panel for attachment (
(not shown) and perform seal welding. This forms the side wall portion of the inner tank structure (membrane) that substantially accommodates the cold storage liquid.

Next, the bottom panel 5 is carried into the tank and the bottom inner wall 3
can be attached to. The lower panel 5 is attached from the outer panel 4. The lower panel 5 will be lowered directly below the construction opening by a large crane, but the casters 23
, the bottom inner wall 3 can be easily moved to a predetermined position.

Positioning of the inside of the bottom panel 5 with respect to 3 can be easily accomplished by aligning the convex portion 30 formed on the bottom surface of the panel 5 with the positioning hole 31 of the bottom inner wall 3. After positioning the lower panel 5, the wheels 24 of the casters 23
The lower panel 5 is lowered and is seated on the bottom inner wall 3 by storing the lower panel 5 in the two wheel accommodating parts. At this time, the convex portion 3
0 is fitted into the positioning six 31, so that the lower panel 5 is prevented from moving laterally after being seated. After the bottom panels 5 are seated on the bottom inner wall 3, membrane panels (not shown) for attachment are attached between adjacent bottom panels 5 and between adjacent side panels 4 and bottom panels 5, and seal welding is performed. As a result, an inner tank structure (membrane) that substantially accommodates the low-temperature storage liquid is formed within the concrete tank body 1.

After forming the inner tank structure (membrane) in the tank body 1 in this way, the construction opening opened in the tank roof is closed and the roof is repaired.

Between the concrete panel 6.20 and the membrane panel 8.22 which constitute the side panel 4 and the bottom panel 5,
Since the cold insulation layer 7.21 is formed in advance, the cold insulation work inside the tank can be reduced, and the work inside the tank can be greatly simplified.

In addition, by setting the dimensions of the concrete panel 6.20 as large as possible for transportation, we added a cold insulation layer 7.21 to the concrete panel 6.20.
Membrane panels 8, 22 integrally formed via
Since the adjacent membrane panel 8 can also be formed large,
, 22 can be reduced, workability is significantly improved, and reliability is also improved.

In addition, since the process of forming the cold insulation layer 7.21 on the concrete panel 6.20 and integrally forming the membrane panel 8.22 through the cold insulation layer can be performed in a factory, etc., the side panel 4 and the bottom panel 5. Products with good quality and precision can be manufactured.

Therefore, the construction period can be significantly shortened and reliability can also be greatly improved.

In addition, in the above embodiment, the inner wall of the side part of the concrete tank body is formed in a polygonal shape, and the side wall panel is formed in a rectangular shape to match the shape of the inner wall, but the inner wall shape and panel shape are limited to this. Instead, the side inner wall of the tank body may be formed into a cylindrical shape, and the side wall panel may be formed into an arcuate cross section. In this case, the side wall panel of the bottom panel and I'
j! It goes without saying that the surface in contact with I is formed to have an arcuate cross section.

``Effects of the Invention 1'' In short, the present invention can exhibit the following excellent effects.

(1) Since the number of seal welding points between adjacent membrane panels can be reduced, construction time can be significantly shortened and high reliability can be ensured.

(2) Since the cold storage work can be reduced, the work can be simplified.

(3) Since a membrane panel, cold insulation layer, and concrete panel can be manufactured in a single unit in a factory, a product with high precision can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts showing one embodiment of the present invention, and FIG. 2 (
a) is a plan view showing the side panel, FIG. 2(b) is a side view, FIG. 2(c) is a rear view, FIG. 3(a) is a plan view showing the bottom panel, and FIG. b) is a side view, FIG. 3(c) is a rear view, FIG. 4 is a vertical sectional view of section B in FIG. 1, FIG. 5 is a perspective view showing the mounting bracket, and FIG. FIG. 7 is a partially cutaway perspective view showing the caster. In the figure, 1 is a concrete tank body, 2 is a side inner wall, 3 is a bottom inner wall, 6.20 is concrete 1 to panel, 7.21 is a cold insulation layer, and 8 and 22 are membrane panels. Patent applicant: Ishikawajima-Harima Heavy Industries Co., Ltd. Representative patent attorney: Nobuo Kinutani (1 other person) JP-A-4-439
8 (t)) Figure 5

Claims (1)

[Claims] 1. A method for constructing an underground tank in which a bottomed cylindrical concrete tank is constructed underground, and then a membrane is formed on the inner wall of the concrete tank to accommodate low-temperature storage liquid,
In order to cover the inner wall of the concrete tank body, a membrane panel is integrally formed with a concrete panel divided into predetermined sizes through a cold insulation layer, and the concrete panel is made of concrete in the form of a cylinder with a bottom. A method for constructing an underground tank, characterized in that it is attached to the inner wall of the tank body.