JP6914103B2 - Storage tank outflow prevention structure - Google Patents

Description

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

Conventionally, an outdoor storage tank in which a liquid having a large environmental load or a liquid that is a dangerous substance is stored is provided with a liquid barrier so as to surround the storage tank. The liquid levee is a levee to prevent the contents of the storage tank from flowing out of the site should it flow out. The liquid barrier is sized according to the capacity of the storage tank, and is constructed by, for example, a reinforced concrete structure or an earthen structure.

Further, in an oil storage tank provided on the sea, for example, as described in Patent Document 1 and the like below, a floating barrier is provided. The floating barrier was provided by surrounding the oil storage tank with floating bodies, rods, booms, and the like.

Japanese Unexamined Patent Publication No. 61-146908

However, in the conventional liquid barrier provided around the outdoor storage tank, a large amount of seawater may reach the storage tank over the liquid barrier in the event of a tsunami or storm surge. The tank may be damaged. Then, when the contents flow out from the storage tank due to damage, a large amount of seawater etc. exists in the surroundings, so there is a new problem that the flowed contents may flow out beyond the liquid barrier. Was done.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a storage tank outflow prevention structure capable of preventing the contents of the storage tank from flowing out to the outside.

In order to achieve the above object, the outflow prevention structure of the storage tank according to the present invention has a storage portion provided on the top side of the side wall of the storage tank and the contents of the storage tank are opaque and flexible. The storage tank is made of a material to be provided, is stored in the storage portion in a state where the upper end side is supported by the top side of the side wall, and is provided with a shielding curtain that can be deployed downward so as to be separated from the side wall and face the side wall. A liquid barrier is provided around the water barrier, and when the shielding curtain is deployed, the lower end of the shielding curtain is arranged below the upper end of the liquid barrier .

According to the outflow prevention structure of the storage tank of the present invention, the flexible shielding curtain is stored in the storage portion provided on the top side in a state of being supported by the top side of the side wall of the storage tank on the upper end side. There is. Therefore, the shielding curtain can be easily surrounded by the shielding curtain by storing the shielding curtain in the storage portion at normal times and deploying it downward from the storage portion at the time of use.

Since this shielding curtain can be deployed so as to be separated from the side wall and opposed to the side wall, when the contents flow out from the storage tank, or when there is a risk of outflow, when the shielding curtain is deployed downward, the shielding curtain can be deployed in the storage tank. It can be placed at intervals along the side wall.
Therefore, for example, when a tsunami or storm surge occurs and a large amount of seawater reaches the circumference of the storage tank, when the shielding curtain expands and the lower end side is immersed in seawater, the liquid level around the storage tank is shielded. Can be partitioned from the outside. As a result, even if the contents of the storage tank leak, it is possible to prevent the contents floating on the sea surface 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 contents flow out in a state where a large amount of liquid (seawater) is present around the storage tank.

Further, 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 contents flow out, the flowed out contents float on 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 reliably immersed in the surrounding liquid, and the contents floating on the liquid surface can be stored in the storage tank. It can be reliably retained between the shield curtain and the shield curtain.

In the outflow prevention structure of the storage tank according to the present invention, the storage portion has a holding portion for holding the shielding curtain and an operating portion for opening the holding portion and dropping the shielding curtain by its own weight. The operating portion may be configured to operate according to a predetermined change in the storage tank.
According to this storage tank outflow prevention structure, when the operating portion operates according to a predetermined change in the storage tank, the holding portion that holds the shielding curtain can be opened and the shielding curtain can be dropped by its own weight. Therefore, a shielding curtain can be deployed around the side wall of the storage tank with a simple configuration.

In the outflow prevention structure of the storage tank according to the present invention, a plurality of the storage portions are provided on the top side of the side wall of the storage tank at intervals in the circumferential direction, and the shielding curtain is configured to be deployable in the circumferential direction. The shielding curtains that are adjacent to each other may be configured to be deployable so as to overlap each other in the circumferential direction.
According to the outflow prevention structure of this storage tank, a plurality of storage parts are provided at intervals in the circumferential direction, and each storage part is configured to store a shielding curtain, so that the storage parts are arranged in the circumferential direction. It is not necessary to provide them in a continuous shape, and the structure of the storage unit can be simplified.
Then, even if the storage portions adjacent to each other are separated from each other, the shielding curtain stored in the storage portion can be deployed in the circumferential direction (width direction) along the side wall, so that the storage portions can be dropped from the plurality of storage portions and deployed. At that time, it is possible to prevent the formation of a gap 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 outflow prevention structure of the storage tank according to the present invention, a rail is provided on the top side of the side wall of the storage tank so as to face the side wall at a distance from the side wall and over the entire circumference, and the rail is provided with the rail. Shielding curtains are continuously provided, and the shielding curtains may be configured as a single piece all around.
According to the outflow prevention structure of this storage tank, since the shielding curtain is composed of a single piece that is integrated all around, it is surely prevented that a gap is formed in the circumferential direction when the shielding curtain is deployed. 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 outflow prevention structure of the storage tank according to the present invention, the storage portion may be provided so as to project outward so as to be separated from the side wall of the storage tank.
According to this storage tank outflow prevention structure, since the storage portion is provided so as to project outward so as to be separated from the side wall of the storage tank, the side wall of the storage tank can be dropped by dropping the shielding curtain from the storage portion by its own weight. The shielding curtain can be easily deployed at a position away from the storage tank even if an obstacle protrudes from the storage tank.

In the outflow prevention structure of the storage tank according to the present invention, a weight may be attached to the lower end side of the shielding curtain.
According to this outflow prevention structure of the storage tank, 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 weight allows the lower end side of the shielding curtain to be more quickly settled in the liquid and immersed.
After that, by providing a weight, it is possible to prevent the lower end side of the shielding curtain from floating, and the lower end side of the shielding curtain can be stably immersed in the liquid.

According to the outflow prevention structure of the storage tank of the present invention, it is possible to prevent the contents of the storage tank 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 schematic partial cross-sectional view along the line AA of FIG. It is a schematic perspective view which shows the state in which the shielding curtain is unfolded in the storage tank provided with the outflow prevention structure which concerns on embodiment of this invention. FIG. 3 is a schematic partial cross-sectional view taken along the line BB of FIG. 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, the outflow prevention structure of the storage tank according to the 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 contains a large amount of liquid as the content 14, and is, for example, a large tank constructed on the ground such as a seaside complex. The storage tank 10 is installed at a place where a large amount of seawater is expected to come in during a tsunami, storm surge, or the like.

Further, the content 14 of the storage tank 10 is a fluid, a powder or granular material, a liquid, a slurry or the like that floats in the liquid, and in the present embodiment, a flammable liquid such as heavy oil, petroleum, or various oils or It is a liquid that has a large environmental load.
Then, the outflow prevention structure 20 of the storage tank 10 stores the contents 14 that have flowed out into the liquid that has flowed from the storage tank 10 to the surroundings in order to prevent the contents 14 from diffusing at the liquid surface and flowing out to the outside of the site. It 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 type 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 stairs, wind garters, and overflow pipes 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 unit 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 unit 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 unit 21 is provided so as to project 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 of the storage chamber 24. It has a holding portion 27 that opens and closes the 26, and an operating portion 28 that can open the holding portion 27.

The base portion 23 may be integrally constructed with the side wall 12 of the storage tank 10, or may be formed separately and mounted on the side wall 12 after the construction of the storage tank 10. In the present embodiment, the main body portion 25 (storage chamber 24) formed integrally with the base portion 23 by sandwiching the upper end of the side wall 12 of the storage tank 10 is installed.
The main body 25 is provided with a storage chamber 24 having an opening 26 facing downward. The shielding curtains 31 are stored in the storage chambers 24 in a folded state. The upper end of the shielding curtain 31 is supported and fixed to the top in the storage chamber 24.

The holding portion 27 is configured as an opening / closing door that closes the downward opening 26 provided in the storage chamber 24. The holding portion 27 including the opening / closing door is pivotally supported by the storage chamber 24 at one edge portion, and the shielding curtain 31 is configured to be openable downward as shown by a virtual line in the drawing.
When the holding portion 27 formed of the opening / closing door closes the opening 26 from below, the holding portion 27 holds the shielding curtain 31 in the folded state.

The operating portion 28 has a locking mechanism for locking the holding portion 27 including the opening / closing door. When the operating portion 28 is activated, as shown by a virtual line in the figure, the holding portion 27 is opened downward by releasing the locked state, and the shielding curtain 31 can be expanded downward by its own weight. ing.

In the present embodiment, the operating unit 28 is configured to operate according to a predetermined change in the storage tank 10. Here, the predetermined change of the storage tank 10 is not particularly limited, but for example, a vibration applied to the side wall 12 of the storage tank 10 and a water level change of the sea level 16a (see FIG. 4) in the vicinity of the storage tank 10. , The water level of the content 14 in the storage tank 10 may drop, the seismic intensity of the earthquake may exceed a predetermined value, or the like.

For example, when the operating portion 28 is operated by the vibration applied to the side wall 12, when the side wall 12 is vibrated or accelerated by a predetermined value or more, the locked state is released and the operating portion 28 is operated. Should be used.
Further, when the operation is performed by lowering the water level of the seawater surface 16a of the seawater 16 in the vicinity of the storage tank 10 or the water level of the content 14 in the storage tank 10, for example, the water level of the seawater surface 16a or the liquid level of the content 14 is adjusted. A float that moves up and down accordingly may be provided, and a mechanical lock mechanism or the like that is released from the locked state by the operation of the float may be used.
In any form, it is preferable that the operating portion 28 of the present embodiment has a structure in which a driving force can be obtained without power supplied from the outside.

The shielding curtain 31 is a material that does not penetrate the contents 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 by the top side of the side wall 12. The support structure is not particularly limited, but 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, as shown by a virtual line in FIG. 1, the upper end side of the shielding curtain 31 can be guided along the circumferential direction of the storage tank 10 between the main bodies 25 and 25 of the storage portions 21 and 21 adjacent to each other. 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 curtains 31 may have a shape that can face the side wall 12 by being arranged along the side wall 12 in a state of being separated from the side wall 12 of the storage tank 10, and are formed in a flat strip shape having a predetermined width. You may.
The upper end of each shielding curtain 31 is supported at the top side of the side wall 12 and faces the side wall 12 of the storage tank 10, and is arranged at least above the maximum sea level 16a assumed around the storage tank 10. Just do it. In the present embodiment, the upper end of each shielding curtain 31 is arranged above the upper end of the liquid barrier 11.

On the other hand, the lower end of each shielding curtain 31 is preferably arranged at the lowest possible position while being supported by the top side of the side wall 12 and facing the side wall 12 of the storage tank 10 (the shielding curtain 31 is expanded). For example, one having a size that is arranged at a position equivalent to the lower end of the side wall 12 may be used.
The lower end of each shielding curtain 31 is preferably arranged below the upper end of the liquid barrier 11, and is configured to be arranged below the upper end of the liquid barrier 11 over the entire length of the storage tank 10 in the circumferential direction. There is.

Further, the length of each shielding curtain 31 in the width direction can be appropriately selected, but the shielding curtains 31 are stored in a state of being arranged facing the side wall 12 of the storage tank 10 (a state in which the shielding curtain 31 is deployed). It suffices if it is formed to have a width capable of continuously covering the entire circumference of the side wall 12 of the tank 10. For example, the length of the shielding curtain 31 of each storage unit 21 in the width direction may be halved or more of the distance between the cores of 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 inside and outside.

A weight 33 is attached to the lower end side of each shielding curtain 31. The weight of the weight 33 may be appropriately set according to the material of the shielding curtain 31, and the weight may be such that at least the lower end side of the shielding curtain 31 can be reliably immersed in the seawater 16 around the storage tank 10.
The weight 33 may be attached directly to the lower end side of the shielding curtain 31, or may be attached so as to be arranged below the shielding curtain 31.
Further, the weight 33 may be arranged in a suspended state in the seawater 16 at a position where it does not reach the ground 15, so that the shielding curtain 31 may be constantly subjected to downward tension.

Each of the shielding curtains 31 is stored in the storage chamber 24 of the storage unit 21 in a foldable state so as to be unfoldable. The method of storing is not limited in any way, and for example, it may be wound in the vertical direction around the winding center along the horizontal direction, or may be randomly bundled in a reduced shape.
In the present embodiment, since the storage chambers 24 and 24 of the storage portions 21 and 21 adjacent to each other are provided at intervals from each other, the length in the width direction of the shielding curtain 31 is larger than the length in the width direction of the storage chamber 24. It is formed long. Therefore, in the stored 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 shielding curtain 31 in the stored state can be deployed downward by falling due to its own weight while being supported on the upper end side.
At the same time, the shielding curtain 31 falls due to its own weight, so that at least one of the shielding curtains 31 and 31 stored in the storage portions 21 and 21 adjacent to each other, preferably both, expands in the circumferential direction (width direction) along the side wall 12. However, the shielding curtains 31, 31 adjacent to each other are configured to be deployable so as to be arranged close to each other or continuously.

In the storage tank 10 provided with such an outflow prevention structure 20, seawater 16 does not normally exist around the storage tank 10, and the contents 14 are stored in the storage tank 10 without leakage. In the outflow prevention structure 20, the shielding curtain 31 is stored in the storage chamber 24 of the storage unit 21 in a folded state. In this state, the holding portion 27 including the opening / closing door is closed.

As shown in FIGS. 3 and 4, for example, when a tsunami, a storm surge, or the like occurs and the seawater 16 crosses the liquid barrier 11 and reaches the side wall 12 of the storage tank 10, the side wall 12 of the storage tank 10 is affected by the impact or the like. 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 is impacted, the water level around the outside of the storage tank 10 rises, or the liquid level of the contents 14 in the storage tank 10 drops, the operating portion 28 moves. Operate. As a result, the holding portion 27 including the opening / closing door is released from the lock, and the holding portion 27 is opened.

When the holding portion 27 including the opening / closing door is opened, the shield curtain 31 in the stored state mounted on the holding portion 27 expands 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, when it is used, it falls from the storage portion 21 and expands downward so as to be separated from the side wall 12 and faces the side wall 12, and a plurality of circumferences of the side wall 12 of the storage tank 10 are formed. It is deployed so as to be surrounded by a shielding curtain 31.

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

As a result, the content 14 that has flowed out of the storage tank 10 and floated on the surrounding sea surface 16a can be retained on the sea surface 16a between the shielding curtain 31 and the side wall 12 of the storage tank 10, and is a liquid barrier. It is possible to prevent the content 14 from diffusing to the outside of 11 and collect it.

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

Since the shielding curtain 31 can be deployed so as to be separated from the side wall 12 and opposed to the side wall 12, when the content 14 flows out from the storage tank 10 or when there is a risk of the content 14 flowing out, when the shielding curtain 31 is deployed downward, the shielding curtain 31 is deployed. 31 can be spaced apart along the side wall 12 of the storage tank 10.
Therefore, when a large amount of seawater 16 reaches the storage tank 10 and a large amount of seawater 16 exists in the surroundings, 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 The 16a can be partitioned from the outside by the shielding curtain 31. As a result, the contents 14 that have flowed out to the sea surface 16a can be retained between the storage tank 10 and the shielding curtain 31 and can be prevented from flowing out to the outside.

Further, in the outflow prevention structure 20 of the storage tank 10 of the present embodiment, a liquid barrier 11 is provided around the storage tank 10, and the lower end of the shielding curtain 31 is arranged 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 beyond the liquid barrier 11 and the storage tank 10 is damaged and the contents 14 flow out, the outflow contents 14 rise to the sea level 16a. do. At that time, if the lower end of the shielding curtain 31 is arranged 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, the content 14 floating on the sea surface 16a can be retained 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 has a holding unit 27 for holding the shielding curtain 31, and an operating unit 28 for opening the holding unit 27, and the operating unit 28 is the storage tank. It is configured to operate with 10 predetermined changes. Therefore, when the operating portion 28 operates due to a predetermined change in the storage tank 10, the holding portion 27 holding the shielding curtain 31 can be opened and the shielding curtain 31 can be dropped by its own weight. As a result, 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 units 21 are provided at intervals in the circumferential direction, and each storage unit 21 is configured to store the shielding curtain 31. Therefore, it is not necessary to provide the storage unit 21 in a shape 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 portion 21 is configured to be deployable in the circumferential direction (width direction) along the side wall 12. Therefore, even if the storage portions 21 and 21 adjacent to each other are separated from each other, when the shielding curtain 31 falls from each storage unit 21 and is deployed, a gap is formed between the shielding curtains 31 and 31 adjacent to each other. Can be prevented. As a result, the contents 14 flowing out of the storage tank 10 can be prevented 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 project 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 portion 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. As a result, even if various facilities such as stairs and wind garter are provided on the side wall 12 of the storage tank 10 so as to project outward, the shielding curtain can be reliably deployed.
Moreover, by deploying the shielding curtain 31 at a position away from the side wall 12 of the storage tank 10, it becomes easy to capture the contents 14 that have flowed out around the storage tank 10.

In the outflow prevention structure 20 of the storage tank 10 of the present embodiment, the weight 33 is attached to the lower end side of the shielding curtain 31. Therefore, when a large amount of seawater 16 reaches the periphery of the storage tank 10 and the water level of the seawater surface 16a rises, and the shielding curtain 31 is deployed downward, when the lower end side of the shielding curtain reaches the seawater surface 16a, The weight 33 allows the lower end side of the shielding curtain 31 to be more quickly settled and immersed in the seawater 16.
Further, after that, the presence of the weight 33 can prevent the lower end side of the shielding curtain 31 from floating, and the lower end side of the shielding curtain 31 can be stably immersed in the seawater 16.

Although one embodiment of the outflow prevention structure 20 of the storage tank 10 according to the present invention has been described above, the present invention is not limited to the above-described embodiment and can be appropriately changed without departing from the spirit of the present invention. be.
For example, in the above embodiment, an example of a storage tank constructed on the ground along the sea has been described, but the present invention is not particularly limited, and there is a possibility that a large amount of fresh water from rivers, lakes, etc. may come into contact with the storage tank installed inland. The storage tank may be provided with an outflow prevention structure. Further, it may be provided in a storage tank which is installed on the sea or in the sea and whose top side protrudes into the air. Further, the large amount of liquid in contact with the storage tank is not limited to seawater 16 and fresh water, and other liquids may be assumed.
Further, in the above embodiment, an example of deploying the shielding curtain 31 when the side wall 12 of the storage tank 10 is damaged and the content 14 flows out has been described, but the content 14 may flow out due to, for example, an earthquake or the like. When this occurs, the shielding curtain 31 may be deployed.

Further, in the above embodiment, an example will be described in which a holding portion 27 composed of an opening / closing door is provided in the opening 26 of the storage chamber 24 as the storage portion 21, and the shielding curtain 31 is placed on the holding portion 27. 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 the door is dropped. In that case, as the holding portion 27, for example, a member or the like that winds and supports the shielding curtain 31 may be used.
Further, although the case where the holding portion 27 as the opening / closing door is provided in the opening 26 has been described, the opening / closing door may not be provided in the opening 26.
Further, in the above embodiment, an example in which the operating portion 28 automatically opens the holding portion 27 by a predetermined change in the storage tank 10 has been described, but the holding portion 27 may be opened by being operated by an operator. good.

Then, as shown in FIG. 5, a rail 40 is arranged along the circumferential direction at a position separated from the side wall 12 of the storage tank 10 by a predetermined distance, and a shielding curtain 131 composed of a single piece integrated on the entire circumference of the rail 40. A configuration may be adopted in which the rail is held in a rolled-up state. With such a configuration, when the shielding curtain 131 is deployed, it is possible to reliably prevent the formation of a gap in the circumferential direction. At this time, a cover may be provided to prevent deterioration of the shielding curtain 131.

10 ... Storage tank 11 ... Liquid barrier 12 ... Side wall 14 ... Contents 15 ... Ground 16 ... Seawater 16a ... Seawater 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 ... Acting part 31, 131 ... Shielding curtain 32 ... Rail 33 ... Weight

Claims (7)

A storage unit provided on the top side of the side wall of the storage tank,
The contents of the storage tank are made of an opaque and flexible material, and are stored in the storage portion with the upper end side supported by the top side of the side wall so as to face the side wall apart from the side wall. With a shielding curtain that can be deployed downwards ,
A liquid barrier is provided around the storage tank, and when the shield curtain is deployed, the lower end of the shield curtain is arranged below the upper end of the liquid barrier. Outflow prevention structure of the storage tank. The storage portion has a holding portion for holding the shielding curtain and an operating portion for opening the holding portion and dropping the shielding curtain by its own weight, and the operating portion operates according to a predetermined change in the storage tank. The outflow prevention structure for a storage tank according to claim 1. A plurality of the storage portions are provided on the top side of the side wall of the storage tank 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 provided in the circumferential direction. The outflow prevention structure for a storage tank according to claim 1 or 2 , wherein the structure can be deployed so as to overlap with each other. On the top side of the side wall of the storage tank, a rail is provided so as to face the side wall at a distance from the side wall and to cover the entire circumference.
The shielding curtain is continuously provided on the rail.
The outflow prevention structure for a storage tank according to claim 1 or 2 , wherein the shielding curtain is composed of a single piece all around. The outflow prevention structure for a storage tank according to any one of claims 1 to 4 , wherein the storage portion is provided so as to project outward so as to be separated from the side wall of the storage tank. The outflow prevention structure for a storage tank according to any one of claims 1 to 5 , wherein a weight is attached to the lower end side of the shielding curtain. A storage unit provided on the top side of the side wall of the storage tank,
The contents of the storage tank are made of an opaque and flexible material, and are stored in the storage portion with the upper end side supported by the top side of the side wall so as to face the side wall apart from the side wall. With a shielding curtain that can be deployed downwards,
A plurality of the storage portions are provided on the top side of the side wall of the storage tank 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 provided in the circumferential direction. A storage tank outflow prevention structure characterized in that it can be deployed so as to overlap with each other.

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