JP2018204211A - Outflow preventing structure of storage tank - Google Patents

Abstract

To provide an outflow preventing structure of a storage tank which can prevent a content of the storage tank from flowing out to an outside.SOLUTION: The present invention comprises a storage portion 21 provided on a top side of a side wall 12 of a storage tank 10 and a shielding curtain 31 which is impermeable to contents 14 of the storage tank and made of a material having flexibility and is stored in the storage portion in a state where an upper end side is supported on the top side of the side wall and that can be deployed downward so as to be separated from the side wall and opposed to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a storage tank outflow prevention structure.

  2. Description of the Related Art Conventionally, in an outdoor storage tank in which a liquid with a large environmental load, a liquid that becomes a dangerous substance, or the like is stored, a liquid barrier is provided so as to surround the storage tank. The dike is a dike to prevent the contents of the storage tank from flowing out of the site if it leaks. The breakwater has a size corresponding to the capacity of the storage tank, and is constructed of, for example, a reinforced concrete structure or a pile structure.

  Moreover, in the oil storage tank provided on the sea, for example, as described in Patent Document 1 below, a floating bank is provided. The levee was built around the oil storage tank using floating bodies, rods, and oil fences.

JP-A-61-146908

  However, in the conventional breakwater provided around the outdoor storage tank, there is a risk that a large amount of seawater etc. may reach the storage tank over the breakwater during a tsunami or storm surge. There is a risk of damage to the tank. When the contents flow out of the storage tank due to damage, there is a new problem that there is a possibility that the outflowed contents may flow out over the breakwater due to the presence of a large amount of seawater, etc. It was done.

  Then, this invention is made | formed in view of the said situation, and it aims at providing the outflow prevention structure of the storage tank which can prevent the content of the storage tank flowing out outside.

  In order to achieve the above object, the storage tank outflow prevention structure according to the present invention has a storage part provided on the top side of the side wall of the storage tank, and the contents of the storage tank are impervious and flexible. A shielding curtain that is housed in the storage portion in a state in which the upper end side is supported on the top side of the side wall and that can be deployed downward so as to face the side wall apart from the side wall. It is a feature.

  According to the storage tank outflow prevention structure of the present invention, the flexible shielding curtain is stored in the storage portion provided on the top side while being supported on the top side of the side wall of the storage tank on the upper end side. Yes. For this reason, the shielding curtain is stored in the storage unit in the normal state, and is expanded downward from the storage unit in use, so that the periphery of the side wall of the storage tank can be easily surrounded by the shielding curtain.

Since this shielding curtain can be deployed so as to face and separate from the side wall, when the contents flow out of the storage tank, or when there is a risk of the outflow, if the curtain is deployed downward, the shielding curtain It can be arranged at intervals along the side wall.
Therefore, for example, when a tsunami or storm surge occurs and a large amount of seawater reaches around the storage tank, when the shielding curtain is deployed and the lower end is immersed in seawater, the liquid level around the storage tank is blocked. Can be partitioned from the outside. Thereby, even if the contents of the storage tank leak, it is possible to prevent the contents floating on the seawater from staying between the storage tank and the shielding curtain and flowing out to the outside.
As a result, it is possible to provide a storage tank outflow prevention structure that can prevent the contents from flowing out when the content flows out in a state where a large amount of liquid (seawater) exists around the storage tank.

In the storage tank outflow prevention structure according to the present invention, a liquid barrier is provided around the storage tank, and when the shielding curtain is deployed, the lower end of the shielding curtain is below the upper end of the liquid barrier. It may be configured to be arranged.
For example, when a large amount of liquid reaches the side wall of the storage tank over the liquid barrier and the storage tank is damaged and the content flows out, the outflowed content rises to the liquid surface. Here, if the lower end of the shielding curtain is arranged below the upper end of the liquid barrier, the lower end side of the shielding curtain can be surely immersed in the surrounding liquid, and the contents floating on the liquid surface can be stored in the storage tank. And the shielding curtain can be reliably retained.

In the storage tank outflow prevention structure according to the present invention, the storage unit includes a holding unit that holds the shielding curtain, and an operation unit that opens the holding unit and drops the shielding curtain by its own weight, The operating unit may be configured to operate by a predetermined change of the storage tank.
According to this storage tank outflow prevention structure, the operating part is operated by a predetermined change of the storage tank, so that the holding part for holding the shielding curtain can be opened and the shielding curtain can be dropped by its own weight. Therefore, it is possible to deploy the shielding curtain with a simple configuration around the side wall of the storage tank.

In the storage tank outflow prevention structure according to the present invention, a plurality of the storage portions are provided at intervals in the circumferential direction on the top side of the side wall of the storage tank, and the shielding curtain is configured to be deployable in the circumferential direction. The shielding curtains adjacent to each other may be configured to be deployable so as to overlap in the circumferential direction.
According to this storage tank outflow prevention structure, the plurality of storage portions are provided at intervals in the circumferential direction, and the storage curtain is stored in each storage portion. There is no need to provide a continuous shape, and the structure of the storage portion can be simplified.
Even if the storage units adjacent to each other are separated from each other, the shielding curtain stored in the storage unit can be deployed in the circumferential direction (width direction) along the side wall. In this case, it is possible to prevent a gap from being formed between the shielding curtains adjacent to each other. As a result, it is possible to prevent the contents flowing out from the storage tank from staying between the shielding curtain and the storage tank and flowing out to the outside.

In the storage tank outflow prevention structure according to the present invention, a rail is provided on the top side of the side wall of the storage tank so as to be spaced apart from the side wall and over the entire circumference. Shielding curtains are continuously provided, and the shielding curtains may be composed of a single piece that is integral with the entire circumference.
According to this storage tank outflow prevention structure, since the shielding curtain is composed of a single piece that is integral with the entire circumference, it is reliably prevented that a gap is formed in the circumferential direction when the shielding curtain is deployed. it can. As a result, it is possible to prevent the contents flowing out from the storage tank from staying between the shielding curtain and the storage tank and flowing out to the outside.

In the storage tank outflow prevention structure according to the present invention, the storage portion may be provided to protrude outward so as to be separated from the side wall of the storage tank.
According to this storage tank outflow prevention structure, the storage portion is provided so as to protrude outward so as to be separated from the sidewall of the storage tank. Even if an obstacle protrudes from, the shielding curtain can be easily deployed at a position spaced from the storage tank.

In the storage tank outflow prevention structure according to the present invention, a weight may be attached to a lower end side of the shielding curtain.
According to this storage tank outflow prevention structure, since the weight is attached to the lower end side of the shielding curtain, the shielding curtain is moved downward in a state where a large amount of liquid reaches the periphery of the storage tank and the liquid level rises. When unfolded, the lower end side of the shielding curtain can be more quickly settled and immersed in the liquid by the weight.
Furthermore, by providing a weight thereafter, the lower end side of the shielding curtain can be prevented from rising, and the lower end side of the shielding curtain can be stably immersed in the liquid.

  According to the storage tank outflow prevention structure of the present invention, the contents of the storage tank can be prevented from flowing out.

It is a schematic perspective view of the storage tank provided with the outflow prevention structure which concerns on embodiment of this invention. It is a general | schematic fragmentary sectional view in alignment with the AA of FIG. It is a schematic perspective view which shows the state which expanded the shielding curtain in the storage tank provided with the outflow prevention structure which concerns on embodiment of this invention. FIG. 4 is a schematic partial sectional view taken along line BB in FIG. 3. It is a schematic perspective view which shows another aspect of the storage tank provided with the outflow prevention structure which concerns on embodiment of this invention.

Hereinafter, a storage tank outflow prevention structure according to an embodiment of the present invention will be described in detail with reference to the drawings.
First, the storage tank 10 provided with the outflow prevention structure of the present embodiment is a large tank constructed on the ground such as a complex along the sea, in which a large amount of liquid is stored as the contents 14. The storage tank 10 is installed in a place where a large amount of seawater is expected to come in the event of a tsunami or storm surge.

In addition, the contents 14 of the storage tank 10 are fluid particles, such as particles, liquids, and slurries that float in the liquid. In the present embodiment, the contents 14 include flammable liquids such as heavy oil, petroleum, and various oils. It is a liquid with a large environmental load.
And the outflow prevention structure 20 of the storage tank 10 is stored in order to prevent the contents 14 that have flowed into the liquid that has rushed to the periphery from the storage tank 10 from diffusing on the liquid surface and flowing out of the site. This is a structure for shielding the tank 10 from the outside.

As shown in FIG. 1, the storage tank 10 of the present embodiment is a floating roof tank having a cylindrical shape. A liquid barrier 11 is provided around the storage tank 10 so as to surround the entire circumference.
Various facilities such as a staircase, a wind garter, and an overflow pipe are installed on the outer periphery of the side wall 12 of the storage tank 10, but detailed illustration is omitted.

  As shown in FIG. 1, the outflow prevention structure 20 includes a storage portion 21 provided on the top side of the side wall 12 of the storage tank 10, and a shielding curtain 31 stored in the storage portion 21. In the present embodiment, a plurality of storage portions 21 are provided on the top side of the side wall 12 of the storage tank 10 at intervals in the circumferential direction.

  As shown in FIG. 2, each storage portion 21 is provided to protrude outward so as to be separated from the side wall 12 of the storage tank 10. Specifically, a base portion 23 fixed to the top of the side wall 12 of the storage tank 10, a main body portion 25 projecting outward from the base portion 23 and having a storage chamber 24, and an opening portion of the storage chamber 24 A holding portion 27 that opens and closes the opening 26, and an operating portion 28 that can open the holding portion 27.

The base portion 23 may be constructed integrally with the side wall 12 of the storage tank 10 or may be formed separately and attached to the side wall 12 after the construction of the storage tank 10. In addition, in this embodiment, it is comprised separately and the main-body part 25 (storage chamber 24) formed integrally with the base part 23 is installed by pinching the upper end of the side wall 12 of the storage tank 10. As shown in FIG.
The main body 25 is provided with a storage chamber 24 having an opening 26 facing downward. In the storage chamber 24, the shielding curtain 31 is stored in a folded state. The upper end of the shielding curtain 31 is supported and fixed to the top of the storage chamber 24.

The holding unit 27 is configured as an open / close door that closes the downward opening 26 provided in the storage chamber 24. The holding portion 27 formed of the opening / closing door is pivotally supported by the storage chamber 24 at one edge portion, and is configured such that the shielding curtain 31 can be opened downward as indicated by a virtual line in the drawing.
In a state where the holding portion 27 composed of an opening / closing door closes the opening portion 26 from the lower side, the holding curtain 27 holds the shielding curtain 31 in a folded state.

  The operating unit 28 includes a lock mechanism that locks the holding unit 27 including an opening / closing door. When the operation unit 28 is operated, as shown by a virtual line in the figure, the holding unit 27 is opened downward by releasing the locked state, and the shielding curtain 31 can be developed downward by its own weight. ing.

  In the present embodiment, the operating unit 28 is configured to operate by a predetermined change of the storage tank 10. Here, the predetermined change of the storage tank 10 is not particularly limited. For example, the vibration applied to the side wall 12 of the storage tank 10 and the water level change of the seawater surface 16a in the vicinity of the storage tank 10 (see FIG. 4). In some cases, the water level of the contents 14 in the storage tank 10 decreases, the seismic intensity of the earthquake becomes a predetermined value or more.

For example, in the case where the operating unit 28 is operated by vibration loaded on the side wall 12, a mechanical lock mechanism that operates when the engagement state is released when vibration or acceleration exceeding a predetermined value occurs on the side wall 12. May be used.
Moreover, when operating by the fall of the water level of the sea level 16a of the seawater 16 near the storage tank 10 or the water level of the contents 14 in the storage tank 10, for example, the water level of the seawater level 16a and the liquid level of the contents 14 A float that moves up and down accordingly may be provided, and a mechanical lock mechanism or the like that releases the locked state by the operation of the float may be used.
In any form, it is preferable that the actuating unit 28 of the present embodiment has a structure in which a driving force can be obtained without electric power supplied from the outside.

The shielding curtain 31 is a material that does not transmit the content 14 at all or has low permeability, and is made of a flexible sheet-like material.
The upper end side of the shielding curtain 31 is supported on the top side of the side wall 12. Although the support structure is not particularly limited, in the present embodiment, the support structure is supported by fixing the upper end in the storage chamber 24 of the storage unit 21. Further, between the main body portions 25 and 25 of the storage portions 21 and 21 adjacent to each other, the upper end side of the shielding curtain 31 can be guided along the circumferential direction of the storage tank 10 as indicated by a virtual line in FIG. The rail 32 may be provided along the side wall 12 in a state of being separated from the side wall 12 of the storage tank 10.

The shielding curtain 31 may be any shape that can be opposed to the side wall 12 by being disposed along the side wall 12 in a state of being separated from the side wall 12 of the storage tank 10, and is formed in a flat strip shape having a predetermined width. May be.
The upper end of each shielding curtain 31 is supported on the top side of the side wall 12 and opposed to the side wall 12 of the storage tank 10, and is disposed at least above the maximum sea level 16 a assumed around the storage tank 10. Just do it. In the present embodiment, the upper end of each shielding curtain 31 is disposed above the upper end of the liquid barrier 11.

On the other hand, the lower end of each shielding curtain 31 is supported at the top side of the side wall 12 and opposed to the side wall 12 of the storage tank 10 (a state in which the shielding curtain 31 is unfolded). For example, the thing of the magnitude | size arrange | positioned in the position equivalent to the lower end of the side wall 12 should just be used.
The lower end of each shielding curtain 31 is preferably disposed below the upper end of the liquid barrier 11 and is configured to be disposed below the upper end of the liquid barrier 11 over the entire circumferential length of the storage tank 10. Yes.

  Further, the length of each shielding curtain 31 in the width direction can be selected as appropriate. However, the storage curtains 31 are stored in a state where all the shielding curtains 31 are disposed opposite to the side walls 12 of the storage tank 10 (a state where the shielding curtains 31 are deployed). What is necessary is just to be formed in the width | variety which can cover the perimeter of the side wall 12 of the tank 10 continuously. For example, the length in the width direction of the shielding curtain 31 of each storage unit 21 may be set to a length of ½ or more of the inter-center distance between the storage units 21 adjacent to each other on both sides. More preferably, the side edges of the shielding curtains 31 adjacent to each other are arranged so as to overlap each other.

A weight 33 is attached to the lower end side of each shielding curtain 31. The weight 33 may be set as appropriate according to the material of the shielding curtain 31, and at least the lower end side of the shielding curtain 31 may be set to a weight that can be surely immersed in the seawater 16 around the storage tank 10.
The weight 33 may be directly attached to the lower end side of the shielding curtain 31 or may be attached so as to be disposed below the shielding curtain 31.
Furthermore, the weight 33 may be placed in a suspended state at a position that does not reach the ground 15 in the seawater 16, so that a downward tension is always applied to the shielding curtain 31.

Each of the shielding curtains 31 is stored in a retractable state in the storage chamber 24 of the storage unit 21. The storing method is not limited at all. For example, it may be wound around the winding center in the horizontal direction in the vertical direction, or may be bundled in a reduced shape at random.
In the present embodiment, the storage chambers 24, 24 of the storage units 21, 21 adjacent to each other are provided at a distance from each other, so that the length in the width direction of the shielding curtain 31 is greater than the length in the width direction of the storage chamber 24. It is formed long. Therefore, in the storage state, it is necessary that the shielding curtain 31 is stored not only in the vertical direction but also in the width direction.

In any of the storage methods, it is necessary that the storage curtain 31 in the storage state can be expanded downward by dropping due to its own weight while being supported on the upper end side.
At the same time, when the shielding curtain 31 falls due to its own weight, at least one of the shielding curtains 31, 31 stored in the storage units 21, 21 adjacent to each other, preferably both, develop in the circumferential direction (width direction) along the side wall 12. And it is comprised so that expansion | swelling is possible so that the shielding curtains 31 and 31 which mutually adjoin may be arrange | positioned adjacently or continuously.

  In the storage tank 10 provided with such an outflow prevention structure 20, the seawater 16 does not exist in the surrounding area at normal times, and the contents 14 are stored in the storage tank 10 without leakage. The outflow prevention structure 20 is stored in the storage chamber 24 of the storage unit 21 with the shielding curtain 31 folded. In this state, the holding portion 27 including the open / close door is closed.

As shown in FIGS. 3 and 4, for example, when a tsunami, storm surge, or the like occurs and the seawater 16 reaches the side wall 12 of the storage tank 10 across the breakwater 11, the side wall 12 of the storage tank 10 is caused by the impact or the like. It may be damaged. If the side wall 12 is damaged, the contents 14 of the storage tank 10 may leak.
In such a case, the outflow prevention structure 20 is configured to function. Specifically, when the side wall 12 receives an impact, when the water level around the outside of the storage tank 10 rises, or when the liquid level of the contents 14 in the storage tank 10 falls, the operating unit 28 is Operate. Thereby, the latching of the holding part 27 composed of the opening / closing door is released, and the holding part 27 is opened.

When the holding portion 27 including the opening / closing door is opened, the shield curtain 31 placed in the holding portion 27 in the retracted state develops downward from the opening 26 of the storage chamber 24 by its own weight.
Since the upper end side of the shielding curtain 31 is supported, the shielding curtain 31 is dropped from the storage unit 21 during use so that the shielding curtain 31 expands downward so as to face and separate from the side wall 12. It is developed so as to be surrounded by the shielding curtain 31.

In a state where the shielding curtain 31 is deployed, the upper end side is disposed above the sea water surface 16a around the storage tank 10, and the lower end side is disposed in the sea water 16 and immersed therein.
Further, both side edges in the width direction of the upper end of the shielding curtain 31 are developed in the width direction by sliding along the rail 32, for example, and are continuously arranged without forming a gap between the adjacent shielding curtains 31 and 31. Is done.

  As a result, the content 14 that has flowed out of the storage tank 10 and floated on the surrounding seawater surface 16 a can be retained on the seawater surface 16 a between the shielding curtain 31 and the side wall 12 of the storage tank 10. 11 can be recovered while preventing the contents 14 from diffusing to the outside.

  According to the outflow prevention structure 20 of the storage tank 10 of the present embodiment as described above, the top side of the storage curtain 10 having flexibility is supported on the top side of the side wall 12 of the storage tank 10 on the upper end side. Is stored in the storage unit 21 provided in Therefore, at the normal time, the shielding curtain 31 is stored in the storage unit 21, and when used, the periphery of the side wall 12 of the storage tank 10 can be easily surrounded by the shielding curtain 31 by deploying downward from the storage unit 21.

Since the shielding curtain 31 can be deployed so as to be opposed to the side wall 12, when the contents 14 flow out from the storage tank 10 or when there is a risk of the leakage, the shielding curtain 31 is developed downward. 31 can be arranged along the side wall 12 of the storage tank 10 at intervals.
Therefore, when a large amount of seawater 16 reaches the storage tank 10 and a large amount of seawater 16 exists in the surrounding area, when the shielding curtain 31 is deployed and the lower end side is immersed in the seawater 16, the seawater surface around the storage tank 10 16 a can be partitioned from the outside by the shielding curtain 31. As a result, it is possible to prevent the content 14 flowing out to the sea surface 16a from staying between the storage tank 10 and the shielding curtain 31 and flowing out to the outside.

Further, in the outflow prevention structure 20 of the storage tank 10 of the present embodiment, the liquid barrier 11 is provided around the storage tank 10, and the lower end of the shielding curtain 31 is disposed below the upper end of the liquid barrier 11.
When a large amount of seawater 16 reaches the side wall 12 of the storage tank 10 over the breakwater 11 and the storage tank 10 is damaged and the content 14 flows out, the outflowed content 14 floats on the seawater surface 16a. To do. At that time, if the lower end of the shielding curtain 31 is disposed below the upper end of the liquid barrier 11, the lower end side of the shielding curtain 31 can be surely immersed in the surrounding seawater 16. Therefore, it is possible to retain the contents 14 floating on the seawater surface 16 a between the storage tank 10 and the shielding curtain 31.

  In the outflow prevention structure 20 of the storage tank 10 of the present embodiment, the storage unit 21 includes a holding unit 27 that holds the shielding curtain 31 and an operation unit 28 that opens the holding unit 27, and the operation unit 28 is the storage tank. It is configured to operate at 10 predetermined changes. Therefore, when the operation unit 28 is activated by a predetermined change of the storage tank 10, the holding unit 27 that holds the shielding curtain 31 can be opened and the shielding curtain 31 can be dropped by its own weight. Thereby, the shielding curtain 31 can be easily deployed around the side wall 12 of the storage tank 10.

In the outflow prevention structure 20 of the storage tank 10 of the present embodiment, a plurality of storage portions 21 are provided at intervals in the circumferential direction, and the shielding curtain 31 is stored in each storage portion 21. Therefore, it is not necessary to provide the storage unit 21 in a shape that is continuous in the circumferential direction, and the structure of the storage unit 21 can be simplified.
Further, the shielding curtain 31 stored in the storage unit 21 is configured to be deployable in the circumferential direction (width direction) along the side wall 12. Therefore, even if the storage units 21 and 21 adjacent to each other are separated from each other, when the shielding curtain 31 is dropped from each storage unit 21 and deployed, a gap is formed between the shielding curtains 31 and 31 adjacent to each other. Can be prevented. As a result, it is possible to prevent the content 14 flowing out of the storage tank 10 from staying between the shielding curtain 31 and the storage tank 10 and flowing out to the outside.

In the outflow prevention structure 20 of the storage tank 10 of the present embodiment, the storage portion 21 is provided so as to protrude outward so as to be separated from the side wall 12 of the storage tank 10. Therefore, when the shielding curtain 31 is dropped from the storage unit 21 by its own weight and deployed downward, the shielding curtain 31 can be deployed at a position separated from the side wall 12 of the storage tank 10. Thereby, even if various facilities, such as a staircase and a wind garter, are projected outside on the side wall 12 of the storage tank 10, the shielding curtain can be reliably deployed.
Moreover, by deploying the shielding curtain 31 at a position separated from the side wall 12 of the storage tank 10, the contents 14 that have flowed out around the storage tank 10 can be easily captured.

In the outflow prevention structure 20 of the storage tank 10 of this embodiment, a weight 33 is attached to the lower end side of the shielding curtain 31. Therefore, when a large amount of seawater 16 arrives around the storage tank 10 and the water level of the seawater surface 16a rises, when the shielding curtain 31 is deployed downward, the lower end side of the shielding curtain reaches the seawater surface 16a. With the weight 33, the lower end side of the shielding curtain 31 can be submerged and immersed in the seawater 16 faster.
Further, after that, the weight 33 can prevent the lower end side of the shielding curtain 31 from rising, and the lower end side of the shielding curtain 31 can be stably immersed in the seawater 16.

As mentioned above, although one Embodiment about the outflow prevention structure 20 of the storage tank 10 by this invention was described, this invention is not limited to said Embodiment, It can change suitably in the range which does not deviate from the meaning. is there.
For example, in the above embodiment, an example of a storage tank constructed on the ground along the sea has been described. However, the storage tank is not particularly limited, and there is a possibility that a large amount of fresh water from a river, a lake, or the like is installed inland. An outflow prevention structure may be provided in the storage tank. Moreover, you may provide in the storage tank installed in the sea or in the sea, and the top part protrudes in the air. Furthermore, the large amount of liquid in contact with the storage tank is not limited to seawater 16 or fresh water, and other liquids may be assumed.
Moreover, although the said embodiment demonstrated the example which expand | deploys the shielding curtain 31 when the side wall 12 of the storage tank 10 is damaged and the content 14 flows out, there exists a possibility that the content 14 may flow out like an earthquake etc., for example When this occurs, the shielding curtain 31 may be deployed.

Moreover, in the said embodiment, the holding part 27 which consists of an opening-and-closing door is provided in the opening part 26 of the storage chamber 24 as the storage part 21, and the example in which the shielding curtain 31 is mounted on this holding part 27 is demonstrated. However, the holding portion 27 may be provided separately from the opening / closing door to hold the shielding curtain 31, and the opening / closing door may be opened when dropped. As the holding unit 27 in that case, for example, a member that winds and supports the shielding curtain 31 may be used.
Furthermore, although the case where the holding | maintenance part 27 as an opening / closing door was provided in the opening part 26 was demonstrated, it is not necessary to provide an opening / closing door in the opening part 26. FIG.
In the above-described embodiment, the example in which the operating unit 28 automatically opens the holding unit 27 by a predetermined change of the storage tank 10 has been described. However, the holding unit 27 may be opened by an operator's operation. Good.

  Then, as shown in FIG. 5, a rail 40 along the circumferential direction is arranged at a position away from the side wall 12 of the storage tank 10, and the shielding curtain 131 constituted by a single piece of the entire circumference on the rail 40. It is also possible to adopt a configuration that holds the rolled up state. By comprising in this way, when the shielding curtain 131 is expand | deployed, it can prevent reliably that a clearance gap is formed in the circumferential direction. At this time, a cover for preventing the deterioration of the shielding curtain 131 may be provided.

DESCRIPTION OF SYMBOLS 10 ... Storage tank 11 ... Liquid barrier 12 ... Side wall 14 ... Contents 15 ... Ground 16 ... Sea water 16a ... Sea water surface 20 ... Outflow prevention structure 21 ... Storage part 23 ... Base part 24 ... Storage room 25 ... Main body part 26 ... Opening Part 27 ... Holding part 28 ... Actuating part 31, 131 ... Shielding curtain 32 ... Rail 33 ... Weight

Claims (7)

A storage section provided on the top side of the side wall of the storage tank;
The contents of the storage tank are made of a material that is impermeable and flexible, and the upper end side is supported by the top side of the side wall and is stored in the storage unit so as to be spaced apart from the side wall. And a shielding curtain that can be expanded downward.   A liquid barrier is provided around the storage tank, and the lower end of the shield curtain is arranged below the upper end of the liquid barrier when the shield curtain is deployed. The storage tank outflow prevention structure according to claim 1.   The storage unit includes a holding unit that holds the shielding curtain, and an operation unit that opens the holding unit and causes the shielding curtain to fall by its own weight, and the operation unit is activated by a predetermined change of the storage tank. The storage tank outflow prevention structure according to claim 1 or 2, characterized in that:   On the top side of the side wall of the storage tank, a plurality of the storage portions are provided at intervals in the circumferential direction, the shielding curtain is configured to be deployable in the circumferential direction, and the shielding curtains adjacent to each other are arranged in the circumferential direction. The storage tank outflow prevention structure according to any one of claims 1 to 3, wherein the structure can be deployed so as to overlap with each other. The top side of the side wall of the storage tank is spaced from and opposed to the side wall, and a rail is provided over the entire circumference.
The rail is connected to the shielding curtain,
The storage tank outflow prevention structure according to any one of claims 1 to 3, wherein the shielding curtain is formed of a single piece that is integral with the entire circumference.   The storage tank outflow prevention structure according to any one of claims 1 to 5, wherein the storage portion is provided so as to protrude outward so as to be separated from a side wall of the storage tank.   The storage tank outflow prevention structure according to any one of claims 1 to 6, wherein a weight is attached to a lower end side of the shielding curtain.

Images