JP6008281B2 - Cold tank anchor strap - Google Patents

Description

  The present invention relates to a flat bottom cylindrical double shell cryogenic tank comprising an inner tank for storing a low-temperature liquid such as high pressure gas, liquefied gas, fuel, etc. and an outer tank surrounding the inner tank. The present invention relates to an anchor strap for a low-temperature tank that prevents floating of the tank.

As shown in FIG. 6, a flat bottom cylindrical double shell low temperature tank 1 has an outer tub 1a composed of an outer tub side plate 2, an outer tub bottom plate 3 and an outer tub roof 5 fixed on a base plate 4. An inner tub 1b composed of an inner tub side plate 6, an inner tub bottom plate 7 and an inner tub roof plate 10 is installed on the inner tub bottom refrigeration 8 inside the tub 1a.
The inner tank roof 10 of the inner tank 1b of the low-temperature tank 1 is a fixed roof, and the side plate 6 of the inner tank 1b is lifted by the gas pressure P and thermal contraction force of the gas phase of the tank during normal operation and the seismic load UP. Uplift force such as force is generated. An anchor strap 112 is provided at the lower part of the inner tank side plate 6 so as to correspond to these uplift forces, and this anchor strap 112 is securely installed in an inclined manner with respect to the base plate 4.

  In the invention of Japanese Patent Laid-Open No. 2003-300589 “Storage tank lateral displacement prevention method and storage tank lateral displacement prevention device” of Patent Document 1, a plurality of anchor straps 7 having strap bodies 10 extending to the lower side of the basic slab 3 are arranged, A structure is disclosed in which a weight 17 capable of applying a tensile force to the strap body 10 is attached to the lower end of the anchor strap 7 based on the principle of the lever during an earthquake.

  In the invention of Japanese Patent Laid-Open No. 2007-270864 “Method for installing low-temperature liquefied gas storage facility and anchor strap” of Patent Document 2, a metal inner tub 11 is installed inside a metal outer tub 7, and a heat insulating layer 12, 13, a low temperature liquefied gas storage facility having a concrete base 2 and a metal anchor strap 18 that can be locked downward with respect to the outer peripheral side of the inner peripheral wall to the base to prevent the movement of the inner tank And the structure which formed the anchor strap with the metal material whose linear expansion coefficient is larger than the metal material which forms the inner tank is disclosed.

In the invention of Japanese Patent Application Laid-Open No. 2010-25334 “Anchor of storage tank” of Patent Document 3, the side plate 2s of the inner tub 2 is provided with a locking portion 23 for locking the upper portion 11t of the anchor main body 11, and the anchor main body 11t is disposed on the inner tub 2 side of the locking portion 23, and is disposed at an inclination angle θ1 that is separated from the inner tub 2 toward the lower side, and the opposing surface 23i of the locking portion 23 is the anchor main body 11. A configuration in which the tilt angle θ2 is equal to or greater than the tilt angle θ1 is disclosed.

JP 2003-300589 A JP 2007-270864 A JP 2010-25334 A

An anchor strap 112 is provided at the lower portion of the inner tank side plate 6 in the flat bottom cylindrical double shell low temperature tank 1 including the outer tank 1a and the inner tank 1b shown in FIG. In the inner tank 1b of the low-temperature tank 1, an uplift force due to a gas pressure P or a heat shrinkage force in a gas phase portion of the tank during operation or an uplift force due to an earthquake load UP is applied. In particular, since the inner tank roof 10 of the inner tank 1b has a hermetically sealed structure, the uplift force due to the gas pressure P and the heat contraction force of the tank gas phase portion always acts. For this reason, the anchor strap 112 is inclined and firmly installed on the base plate 4 so as not to be lifted during storage of the low temperature liquid. The anchor strap 112 provided in such an inclination requires time for structural design and stress analysis at the time of design, requires accuracy at the time of construction, and has a complicated structure.
On the other hand, in the case of a suspended deck type flat bottom cylindrical double-shell cryogenic tank with a suspended roof, the suspended roof and the side plate of the inner tank are not a continuous sealed structure. The uplift force by does not work. Further, since the uplift force due to the heat shrinkage force is small, it may not be considered. Therefore, it is only necessary to cope with the uplift force due to the seismic load UP, and it is not reasonable to provide the anchor strap inclined as in the prior art.

  In addition, the anchor strap 7 of Patent Document 1 “Storage lateral displacement prevention method and storage lateral displacement prevention device” can prevent lateral displacement of the inner tank against an earthquake by applying a tensile force to the strap body 10 according to the principle of the lever. The structure is complicated and maintenance is difficult.

  The anchor strap of Patent Document 2 “Cryogenic Liquefied Gas Storage Facility and Anchor Strap Installation Method” is made of a metal material having a linear expansion coefficient larger than that of the metal material forming the inner tub, so that heat generated by the low temperature liquefied gas can be obtained. Although a pulling force acts in response to the contraction, installation and earthquake response are complicated.

  In the invention of Patent Document 3 “anchor of storage tank”, the upper portion 11t of the anchor body 11 is arranged at an inclination angle θ1 so as to be separated from the inner tub 2, and the opposing surface 23i of the locking portion 23 is Although the structure provided by inclination-angle (theta) 2 more than inclination-angle (theta) 1 is disclosed, the setting corresponding to a stock solution was difficult.

The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to protect the inner tank of a flat bottom cylindrical double shell low temperature tank from earthquakes during normal operation. It provides a simple and appropriate low temperature tank anchor strap with greater restraint on the load during an earthquake without considering the uplift force due to gas pressure or thermal contraction in the gas phase of the tank.

The anchor strap of the cryogenic tank according to the invention of claim 1 is an anchor strap provided in the inner tank of the flat bottom cylindrical double shell cryogenic tank, and is supported by a bracket that is separated from and fixed to the lower part of the inner tank side plate. It is installed with a vertical strip plate anchor strap body that is fixed to the base plate at the lower end of the base plate, and supports the uplift force during an earthquake. In the anchor strap of the cryogenic tank characterized in that it is formed , the bracket is formed by a horizontal flat plate, and is formed by providing a substantially triangular support rib at the bottom of the bracket, and in the radial direction of the tank at the center of the bracket A rectangular, elongated U-shaped cutout groove is provided toward the end, and the upper short side of the anchor strap body is inserted into the cutout groove in a loose fit. The upper part of the anchor strap body is locked by a support support, and the long side of the center part of the anchor strap body is inserted into the bottom anchored upper anchor box and the base plate lower anchor box in a loosely fitting manner. The lower part of the anchor strap body is formed by inserting fixing ribs at both ends of the base plate at the lower end of the base plate .

The anchor strap of the cryogenic tank according to the invention of claim 1 is an anchor strap provided in the inner tank of the flat bottom cylindrical double shell cryogenic tank, and is supported by a bracket that is separated from and fixed to the lower part of the inner tank side plate. It is installed with a vertical strip plate anchor strap body that is fixed to the base plate at the lower end of the base plate, and supports the uplift force during an earthquake. In the anchor strap of the cryogenic tank characterized in that it is formed , the bracket is formed by a horizontal flat plate, and is formed by providing a substantially triangular support rib at the bottom of the bracket, and in the radial direction of the tank at the center of the bracket A rectangular, elongated U-shaped cutout groove is provided toward the end, and the upper short side of the anchor strap body is inserted into the cutout groove in a loose fit. The upper part of the anchor strap body is locked by a support support, and the long side of the center part of the anchor strap body is inserted into the bottom anchored upper anchor box and the base plate lower anchor box in a loosely fitting manner. Since the lower part of the anchor strap body is inserted through the opening in the center of the base plate at the lower end of the base plate, and fixing ribs are welded to the overhanging ends ,
Installation of the bracket and the support support, insertion and installation of the strap-like anchor strap body, and fixing of the lower base plate and the fixing rib can be easily performed.
In addition, the side edge of the belt-like anchor strap body is formed in the notch groove at the center of the bracket against the movement of the inner tank side plate in the radial direction due to the thermal contraction and thermal expansion of the inner tank side plate due to the entry and exit of the low temperature liquid and the temperature change Since the anchor strap is inserted in a loose fit, the anchor strap body does not receive a restraining force in the tank radial direction .

It is the whole side explanatory view showing the example of the embodiment which installed the anchor strap of the cryogenic tank concerning the present invention. It is explanatory drawing which expands and shows the A section of FIG. 1, and an anchor strap vicinity. FIG. 3 is an explanatory diagram when FIG. 2 is viewed from the left side of an arrow B. It is perspective explanatory drawing which shows the upper part of an anchor strap. It is perspective explanatory drawing which shows the lower part of an anchor strap. It is whole explanatory drawing which shows the condition which installed the anchor strap of the cryogenic tank of a prior art example.

  An embodiment of an anchor strap for a cryogenic tank according to the present invention will be described with reference to FIGS. The present invention is not limited only to the following embodiments. It goes without saying that changes (for example, omission or addition of components, changes in the shape of components, etc.) can be added to the following embodiments without departing from the gist of the present invention. In addition, the figure shows the outline, only a part is drawn and the detailed structure is omitted.

FIG. 1 is an overall side view illustrating an embodiment in which an anchor strap for a cryogenic tank according to the present invention is installed.
The low temperature tank 1 has a flat bottom cylindrical double shell structure including an outer tank 1a and an inner tank 1b.
The outer tub 1a is composed of an outer tub side plate 2, an outer tub bottom plate 3, and an outer tub roof 5, and is fixed on a base plate 4. A cold insulation space 9 and an inner tub bottom cold insulation 8 are provided inside the outer tub 1a. An inner tub 1 b including an inner tub side plate 6, an inner tub bottom plate 7, and an inner tub roof plate 10 is installed on the inner tub bottom cooler 8.
The inner tank roof 10 of the inner tank 1b of the low-temperature tank 1 is a suspended deck type, that is, a suspended roof 10a structure, and is fixed to the inner side of the outer tank roof 5 by a roof hanging material 11 in a suspended manner. Reference numeral 12 denotes an anchor strap provided at the lower part of the inner tank 1b (shown as A in FIG. 1), and a plurality of anchor straps are provided at equal intervals in the circumferential direction.

As shown in FIG. 1, the gas pressure P in the gas phase of the tank during normal operation is transmitted from the suspended roof 10 a of the inner tank 1 b to the outer tank roof 5 of the outer tank 1 a via the roof suspension material 11.
That is, the up-list force that lifts the inner tub 1b due to the gas pressure P is transmitted to the outer tub roof 5 through the inner tub roof 10a and the suspending material 11, so that the uplift force is lifted to the anchor strap 12 below the inner tub side plate 6. There is no power.
Therefore, the anchor strap 12 is installed vertically from the inner tank side plate 6 to the base plate 4 as shown in part A so as to correspond only to the uplift force applied to the inner tank 1b by the seismic load UP.

FIG. 2 is an explanatory side view showing the vicinity of the anchor strap 12 in the A part of FIG. 1, and FIG. 3 is an explanatory view of FIG.
As shown in FIGS. 2 and 3, the anchor strap 12 passes from the inner tank side plate 6 and the inner tank bottom plate 7 through the bottom cooler 8 and the base plate 4 and is fixed vertically.
The anchor strap 12 has a large cross-sectional area (good cross-sectional performance), a plate having a large plate thickness, a narrow width and a long length, that is, an anchor strap main body 12a having a strip shape, and a substantially triangular support support provided on the upper portion 12b. .., And a rectangular base plate 16 and base fixing ribs 17 provided on the lower portion 12c.
The strip-shaped anchor strap main body 12a has an upper anchor of a rectangular box with the strip width direction as the short side of the strip facing the tank radial direction and the plate length direction as the long side facing the vertical direction of the tank. The box 19 (19a is a bottom wall plate) and the lower anchor box 18 (18a is a bottom wall plate) are vertically inserted with a space therebetween.
As described above, since the space is provided around the anchor strap main body 12a, cold conduction and short path do not occur.
In addition, although illustration is abbreviate | omitted in this gap | interval, it fills with heat insulating materials, such as glass wool and a pearlite material, so that it may not conduct heat.

A flat bracket 14 is provided with a rectangular and elongated U-shaped cutout groove 14a at the center thereof, and is fixed to the inner tank side plate 6 horizontally, and the lower part thereof from the inner tank side plate 6 to the inner tank bottom plate 7 It is supported by substantially triangular bracket support ribs 15, 15 fixed over the end face.
In the notch groove 14a at the center of the bracket 14, the side edge of the short side of the band-like anchor strap body 12a is inserted in a loose fit, and the upper portion 12b is suspended by the support supports 13, 13. Lock.
Even if the inner tank side plate 6 moves in the tank radial direction due to thermal contraction or thermal expansion as the cryogenic liquid enters and exits or changes in temperature, the strip-shaped anchor strap body 12a is formed in the notch groove 14a at the center of the bracket 14. Since the side end edge is inserted in a loose-fitting manner and a movement margin in the tank radial direction is provided, the anchor strap body 12a does not receive a restraining force in the tank radial direction and maintains durability. .

FIG. 4 is a perspective explanatory view showing the vicinity of the upper portion of the anchor strap 12.
A flat bracket 14 is provided with a rectangular and long U-shaped cutout groove 14a at the center, and is welded and fixed horizontally to the inner tank side plate 6 at 14b. The bracket support ribs 15 and 15 having a substantially triangular shape are fixed to the lower portion of the bracket 14, and further fixed and supported by welding from 15 a of the inner tank side plate 6 to 15 b of the upper end surface of the inner tank bottom plate 7.
As indicated by arrows X and Y, the side edge of the short side of the strap-like anchor strap body 12a is inserted into the notch groove 14a at the center of the bracket 14 in a loose-fitting manner (X direction), and the length below it The sides are suspended from above and inserted into the anchor box 19 (Y direction), and the upper part is hooked on the support supports 13, 13.

FIG. 5 is a perspective explanatory view showing the vicinity of the lower part of the anchor strap 12.
An opening 16a is provided at the center of the rectangular flat base plate 16, and the lower portion 12c of the anchor strap body 12a is inserted into and fixed to the opening 16a, and the base fixing ribs 17, 17 are formed on both side surfaces of the protruding lower portion 12c. The periphery is fixed by welding.

As described above, the anchor strap 12 which is in the shape of a belt plate and is vertically installed has a simple structure, is easy to assemble, and is easy to assemble and cope with the uplift force applied to the inner tank 1b by the seismic load UP.

The anchor strap 12 is used not only for a flat bottom cylindrical double-shell low-temperature tank having an inner tank with a suspended roof structure, but also for structures such as tanks and storages of various structures for which protection measures in earthquakes and improvement of seismic performance are desired. Can be applied.

1 Low temperature tank
1a outer tank
1b inner tank
2 Outer tank side plate
3 Outer tank bottom plate
4 editions
5 outer tank roof
6 inner tank side plate
7 inner tank bottom plate
8 bottom cooling
9 inner and outer tank space
10 inner tank roof
11 roof suspension material
12 anchor strap
12a anchor strap body
13 Support support
14 bracket
15 bracket support ribs
16 base plate
17 base fixing rib
18 Lower anchor box
19 upper anchor box

112 anchor strap

P gas pressure
UP earthquake load

Claims (1)

Anchor straps installed in the inner tank of a flat bottom cylindrical double shell cryogenic tank, which are separated from each other and fixed to the bracket fixed to the lower part of the inner tank side plate with a support support, through the bottom cold storage and base plate directly below In the anchor strap of the cryogenic tank, characterized in that it is provided with a vertical band plate-like anchor strap body that is fixed to the base plate at the lower end of the base plate, and is installed to correspond to the uplift force during an earthquake .
The bracket is formed by a horizontal flat plate, and is formed by providing a substantially triangular support rib at the bottom of the bracket, and a rectangular and elongated U-shaped cutout groove in the center of the bracket in the radial direction of the tank. Insert the short side of the upper part of the anchor strap body into the notch groove in a loose fit, and lock the upper part of the anchor strap body with a support support, and the long side of the center part of the anchor strap body is the bottom. The inside of the upper anchor box for cold insulation and the lower anchor box for the base plate are inserted loosely, and the lower part of the anchor strap body is inserted into the opening in the center of the base plate at the lower end of the base plate, and fixing ribs are attached to both ends An anchor strap for a cryogenic tank, which is formed by welding .

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