JP2011148511A - Sloshing load reducing device and ship with sloshing load reducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sloshing load reducing device capable of reducing shaking of the free surface of a liquid stored in a tank, and a ship with the sloshing load reducing device. <P>SOLUTION: The sloshing load reducing device includes: a film body 21 facing the free surface 12 of the liquid 11 in the tank 10 and hagin a degree of freedom in the horizontal direction; supporting means 22a for supporting both end parts of the film body 21 in the tank 10; and stretching means 23 for stretching the film body 21 downward at an intermediate part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sloshing load reducing device and a ship with a sloshing load reducing device that can reduce fluctuation of a free surface of a liquid stored in a tank.

In general, sloshing means that when liquid is transported and stored in the tank, the liquid in the tank moves and synchronizes due to various periodic external forces, resulting in excessive liquid flow in the horizontal, vertical and rotational directions. This is a phenomenon that causes damage to cargo tanks of liquid cargo carriers and oil storage facilities during earthquakes.
Many conventional anti-sloshing measures correspond to floating roof type cylindrical tanks in oil storage facilities, and many of them use mechanisms attached to floating roofs to sink floating roofs that cause damage and fire. The main purpose is to prevent this. On the other hand, as a countermeasure against sloshing when transporting liquid cargo such as ships, a method has been used for a long time to install a partition inside the cargo cage to suppress the movement of the liquid. As a tank structure suitable for the above is devised, ship types having cargo traps, which are difficult to take measures with conventional partition plates, such as LNG ships and chemical tankers, are being built for ships. As countermeasures against sloshing for these types of ships, experiments and numerical calculations are carried out for each tank shape using parameters such as cargo liquid level, oscillating motion, and oscillating cycle as parameters, and dangerous operating conditions are derived and avoided by operations. Currently, there are many restrictions due to restrictions on loading, etc., and operations are inconvenient.
A conventionally proposed sloshing load reducing device will be described below.
There exists a thing as shown by patent document 1 as a sloshing suppression material corresponding to a floating roof type tank. Patent Document 1 proposes a sloshing suppression material that can function even when the floating roof is lowered to the vicinity of the tank bottom. The sloshing suppression material according to Patent Document 1 extends from the outer peripheral end of the floating roof facing the inner wall of the container toward the bottom of the container so as to surround a predetermined region of the liquid stored in the container, It consists of a membrane member connected to.
Patent Document 2 proposes a sloshing prevention device that suppresses sloshing by inhibiting formation of an eigenmode that causes generation of a standing wave. In the anti-sloshing device according to Patent Document 2, an empty chamber filled with gas is disposed on the inner wall of the container.
Patent Document 3 proposes to install a sloshing suppression case near the water surface. This sloshing suppression case temporarily holds the liquid level lifted by sloshing and has a function of releasing the liquid held at an arbitrary time, giving disturbance to periodic liquid level fluctuations and suppressing sloshing. .
In Patent Document 4, a floating frame body that is held near a liquid surface in a liquid storage tank having a cylindrical wall surface by a buoyancy acting from the stored liquid, and that moves in a horizontal direction comes into contact with and constrains the inner wall surface of the liquid. The sloshing suppression device includes a flow resistance imparting member that is supported downward from the floating frame and imparts resistance to the liquid that moves in the horizontal direction near the liquid surface.

JP 2007-253971 A Japanese Patent Laid-Open No. 8-198387 JP-A-60-243596 JP 2006-8148 A

However, a sloshing load reduction device suitable for cases where the tank shape is longer in the horizontal direction than in the vertical direction, such as a tank mounted on a ship, and particularly when the sloshing effect due to fluid fluctuation is large in the longitudinal direction of the tank. Has not been proposed.
And by developing a sloshing suppression mechanism that can handle various shapes of cargo vessels on ships, the size of the cargo cage can be designed freely according to the purpose, and effective and safe transportation of liquid cargo Is possible.

  Accordingly, an object of the present invention is to provide a sloshing load reducing device and a ship with a sloshing load reducing device that can reduce the fluctuation of the free surface of the liquid stored in the tank.

The sloshing load reducing device according to claim 1, wherein the tank for storing the liquid, the film body facing the free surface of the liquid and having a degree of freedom in the horizontal direction, and both ends of the film body in the tank And a tensioning means for pulling the film body downward at the intermediate portion. According to the first aspect of the present invention, when the film body follows and fluctuates due to the free surface deformation caused by the movement of the liquid, the intermediate portion is restrained by the pulling means, so that the flow of the liquid is suppressed and free. Surface fluctuation can be reduced.
According to a second aspect of the present invention, in the sloshing load reducing device according to the first aspect, the film body is set longer than the length of the tank, and an intermediate portion of the film body is slackened downward to be submerged in the liquid. It is characterized by that. According to the second aspect of the present invention, the flow of the liquid moving in the length direction of the tank can be suppressed at the liquid immersion portion of the film body.
According to a third aspect of the present invention, in the sloshing load reducing device according to the first or second aspect, a rope is used as the tension means. According to the third aspect of the present invention, the degree of freedom of deformation of the film body according to free surface deformation can be controlled by pulling the film body with a rope.
According to a fourth aspect of the present invention, in the sloshing load reducing device according to the first or second aspect, a tension film is used as the tension means. According to the fourth aspect of the present invention, it is possible to suppress the flow of the liquid that is also moved by the tension film.
According to a fifth aspect of the present invention, in the sloshing load reducing device according to any one of the first to fourth aspects, the buoyancy of the film body and the density of the liquid are set such that the film body faces a free surface of the liquid. It is characterized by being set in the relationship. According to the fifth aspect of the present invention, the film body can face the free surface of the liquid.
According to a sixth aspect of the present invention, in the sloshing load reducing device according to the fifth aspect, a float for imparting buoyancy to the film body is provided so as to form a convex shape on the upper surface of the film body. According to this invention of Claim 6, the movement of the liquid which runs on the upper surface of a film body can be suppressed.
According to a seventh aspect of the present invention, in the sloshing load reducing device according to any one of the first to sixth aspects, the tension change for changing the length of the tension means in accordance with the height of the free surface of the liquid The apparatus further includes means. According to the seventh aspect of the present invention, the film body can be brought to the height of the free surface of the liquid according to the amount of liquid stored in the tank.
The present invention according to claim 8 is the sloshing load reducing device according to any one of claims 1 to 7, wherein the vertical position of the support means changes according to the deformation of the free surface caused by the movement of the liquid. The apparatus further includes means. According to the eighth aspect of the present invention, the film body can be made to follow the liquid surface even when the free surface of the liquid is particularly unstable.
According to a ninth aspect of the present invention, in the sloshing load reducing device according to the eighth aspect, the upper limit and / or the lower limit of the support means is regulated by the support position adjusting means. According to the ninth aspect of the present invention, the collision of the film body with the tank can be prevented.
According to a tenth aspect of the present invention, in the sloshing load reducing device according to any one of the first to ninth aspects, the film body is stretched by tension means provided at a plurality of locations. According to the tenth aspect of the present invention, it is possible to control the degree of freedom of deformation of the film body in accordance with the free surface deformation.
The invention according to claim 11 is the sloshing load reducing device according to any one of claims 1 to 10, wherein the tension means further includes a buffer means for reducing the impact load. . According to the eleventh aspect of the present invention, it is possible to mitigate the impact on the tension means caused by the movement of the film body.
In a ship with a sloshing load reducing device corresponding to claim 12, the sloshing load reducing device according to any one of claims 1 to 11 is mounted. According to the present invention of the twelfth aspect, it is possible to effectively cope with sloshing caused by hull shaking generated during navigation.
According to a thirteenth aspect of the present invention, in the ship with the sloshing load reducing device according to the twelfth aspect, the tank is arranged such that the length direction of the tank is the ship length direction or the ship width direction. According to the thirteenth aspect of the present invention, the sloshing can be effectively prevented by arranging the tank in a direction in which the sloshing is a concern.

According to the sloshing load reducing device of the present invention, the fluctuation of the free surface of the liquid stored in the tank can be reduced. For example, when applied to a ship, it can handle various shapes of cargo bunker, so the size of the cargo bunker can be designed freely according to the purpose, and it is an effective and safe liquid cargo with a simple structure. Can be transported.
In addition, when the film body is set longer than the tank length and the middle part of the film body is slackened downward and submerged in the liquid, at the liquid immersion part of the film body in the tank length direction. The flow of the moving liquid can be suppressed.
Further, when a rope is used as the pulling means, the deformation degree of the film body according to the free surface deformation can be controlled by pulling the film body with the rope.
In addition, when a tension film is used as the tensioning means, it is possible to suppress the flow of the liquid that is also moved by the tension film.
Further, when the buoyancy of the film body is set in relation to the density of the liquid, the film body can face the free surface of the liquid.
Further, when a float that gives buoyancy to the film body is provided so as to form a convex shape on the upper surface of the film body, the movement of the liquid running on the upper surface of the film body can be suppressed.
Further, in the case of further comprising tension changing means for changing the length of the tension means according to the height of the free surface of the liquid, the film body is attached to the free surface of the liquid according to the amount of liquid stored in the tank. You can face the height of.
Further, in the case of further comprising a support position adjusting means for changing the vertical position of the support means in accordance with the deformation of the free surface due to the movement of the liquid, the film body is placed on the liquid surface even when the free surface of the liquid is largely shaken. It can be made to follow, and it can restrict that excessive force is applied to a film body.
Further, when the upper limit and / or lower limit of the support means is regulated by the support position adjusting means, it is possible to prevent the film body from colliding with the tank while reducing the fluctuation of the free surface of the liquid.
In addition, when the film body is stretched by a stretching means provided at a plurality of locations, the degree of freedom of deformation of the film body according to free surface deformation can be controlled.
Further, when the tensioning means is further provided with a buffer means for reducing the impact load, the impact on the tensioning means and the film body caused by the movement of the film body can be mitigated.
According to the ship with the sloshing load reducing device of the present invention, it is possible to effectively cope with the sloshing caused by the hull shaking generated during navigation.
Also, when the tank is placed so that the tank length direction is the ship length direction or the ship width direction, even if the tank is long, sloshing is effective by placing the tank in a direction where sloshing is a concern. Can be prevented.

(A) is sectional drawing which shows the sloshing load reducing device by the 1st Embodiment of this invention, (b) is the AA arrow directional view in (a), (c) is the BB arrow directional view in (b). Figure Behavior diagram during synchronization of sloshing load reducing device according to this embodiment (A) is sectional drawing which shows the sloshing load reducing device by the 2nd Embodiment of this invention, (b) is the AA arrow directional view in (a), (c) is the BB arrow directional view in (b). Figure Behavior diagram during synchronization of sloshing load reducing device according to this embodiment (A) is sectional drawing which shows the sloshing load reducing device by the 3rd Embodiment of this invention, (b) is the AA arrow directional view in (a), (c) is BB arrow directional view in (b). Figure Sectional drawing which shows the sloshing load reducing device by the 4th Embodiment of this invention Sectional drawing which shows the principal part which shows the sloshing load reducing device by the 5th Embodiment of this invention Sectional drawing which shows the principal part which shows the sloshing load reducing device by the 6th Embodiment of this invention Sectional drawing which shows the principal part which shows the sloshing load reducing device by the 7th Embodiment of this invention (A) is a top cross-sectional view of a main part of a ship with a sloshing load reducing device according to the present embodiment, (b) is a side cross-sectional view of a main part of the ship.

The first embodiment of the sloshing load reducing device of the present invention will be described below.
1A is a cross-sectional view showing the sloshing load reducing device according to the present embodiment, FIG. 1B is a view taken along the line AA in FIG. 1A, and FIG. 1C is in FIG. It is a BB arrow line view.
The sloshing load reducing device according to the present embodiment is applied to a tank 10 made of a rectangular parallelepiped whose longitudinal direction is the horizontal direction. The applicable tank 10 is not limited to a rectangular parallelepiped, but may be a square tank or a cylindrical tank whose top and bottom are inclined, but the length or width dimension is higher than the height dimension. Long type is suitable.
The sloshing load reducing device according to the present embodiment supports a film body 21 that faces the free surface 12 of the liquid 11 in the tank 10 and has a degree of freedom in the horizontal direction, and both ends of the film body 21 in the tank 10. Supporting means 22a and tensioning means 23 for pulling the film body 21 downward at the intermediate portion are provided. Here, the tension means 23 does not have to be centered so as to be bilaterally symmetric as shown in the figure, and it is only necessary to be located between both ends of the film body 21.

The film body 21 is set longer than the length of the tank 10, and an intermediate part of the film body 21 is slackened downward and immersed in the liquid 11. The buoyancy of the film body 21 is set in relation to the density of the liquid 11 so that the film body 21 faces the free surface 12 of the liquid 11.
The support means 22a is provided at the positions of both ends of the short side and the center of the short side of the film body 21, respectively. The support position adjusting means 22b is constituted by a plurality of columnar members provided in the vertical direction along the opposing wall surfaces of the tank 10 in the longitudinal direction. The support means 22a can move up and down along the support position adjusting means 22b made of a columnar member, and the vertical position of the support means 22a changes according to the deformation of the free surface 12 due to the movement of the liquid 11.
The support position adjusting means 22b is provided with support position restricting means 22c and 22d. The support position restricting means 22c restricts the upper limit of the support position adjusting means 22b, and the support position restricting means 22d restricts the lower limit of the support position adjusting means 22b. The support position restricting means 22c and 22d are, for example, protrusions provided on the support position adjusting means 22b, and are members that prevent the support means 22a from moving up and down at a predetermined height.
A plurality of ropes are used for the tension means 23, and one end of the tension means 23 is connected to the film body 21 and the other end is connected to the bottom surface of the tank 10.
A float 24 that provides buoyancy to the film body 21 is provided on the upper surface of the film body 21. The float 24 is provided so as to form a convex shape on the upper surface of the film body 21. The float 24 is a convex member having a predetermined length in the short side direction of the film body 21, and is not disposed at the center of the film body 21, but is provided in a plurality near the respective end portions. The float 24 may be formed separately and attached to the film body 21 or may be formed integrally with the film body 21.
On the other end side of the tension means 23, a tension change means 25 that changes the length of the tension means 23 according to the height of the free surface 12 of the liquid 11 is provided. Further, the other end of the tension means 23 is provided with a buffer means 26 for reducing the impact load. Here, as the buffer means 26, for example, an elastic body such as a spring, a damper by hydraulic pressure or air pressure, or a combination of an elastic body and a damper can be used.

The operating state of the sloshing load reducing device according to the present embodiment will be described with reference to FIG.
FIG. 2 is a behavior diagram during tuning of the sloshing load reducing device according to the present embodiment.
As shown in FIG. 2, the one-end-side film body 21 x follows the deformation of the free surface 12 due to the movement of the liquid 11. At this time, the tension means 23 is in a tension state, and the support means 22a is restrained by the support position restriction means 22c, so that the movement of the one end side film body 21x is suppressed, and as a result, the flow of the liquid 11 is suppressed. At this time, in the other end-side film body 21y, the slackness of the tension means 23 is deformed as shown in FIG. 2 by the action of the tension means 23, and the flow of the right liquid to the left side is reduced.
When the tensioning means 23 is in tension, an impact load is generated in the axial direction, but is relaxed by the buffer means 26. Further, the liquid 11x existing on the upper surface of the film body 21 suppresses the extra swinging of the loose film body 21. And the flow which the liquid 11x which exists in the upper surface of this film body 21 moves to a side surface direction is suppressed by the float 24. FIG.

As described above, according to the present embodiment, when the film body 21 follows and fluctuates due to the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension means 23. 11 can be suppressed to reduce the fluctuation of the free surface 12.
In addition, since the film body 21 is set longer than the length of the tank 10 and the middle part of the film body 21 is slackened downward and immersed in the liquid 11, the tank 10 is immersed in the liquid submerged portion of the film body 21. The flow of the liquid 11 that moves inside can be suppressed.
Further, by using a rope as the pulling means 23 and pulling the film body 21 by the rope, the degree of freedom of deformation of the film body 21 according to the deformation of the free surface 12 can be controlled.
In addition, by setting the buoyancy of the film body 21 in relation to the density of the liquid 11, the film body 21 can face the free surface 12 of the liquid.
In addition, by providing the float 24 so as to form a convex shape on the upper surface of the film body 21, the movement of the liquid 11 running on the upper surface of the film body 21 can be suppressed.
Further, by providing the tension changing means 25, the film body 21 can be made to face the height of the free surface 12 of the liquid 11 according to the amount of the liquid 11 stored in the tank 10.
Further, by providing the support position adjusting means 22b, the film body 21 can be made to follow the liquid surface even when the free surface 12 of the liquid 11 is greatly shaken, and it is possible to limit the excessive force applied to the film body 21. .
Further, by restricting the upper limit position and the lower limit position of the support means 22a by the support position restriction means 22c and 22d, it is possible to prevent the film body 21 from colliding with the tank 10 while reducing the fluctuation of the free surface of the liquid. it can.
In addition, since the film body 21 is pulled by the stretching means 23 provided at a plurality of locations, the degree of freedom of deformation of the film body 21 according to the deformation of the free surface 12 can be controlled.
Further, by providing the buffer means 26, it is possible to reduce the impact on the tension means 23 and the film body 21 caused by the movement of the film body 21.

Hereinafter, a second embodiment of the sloshing load reducing device of the present invention will be described.
3A is a cross-sectional view showing the sloshing load reducing device according to the present embodiment, FIG. 3B is a view taken along the line A-A in FIG. 3A, and FIG. 3C is in FIG. It is a BB arrow line view. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the sloshing load reducing device according to the present embodiment, the film body 21A is set longer than the length of the tank 10, but the intermediate portion of the film body 21A is not submerged in the liquid 11. The buoyancy of the film body 21A is set in relation to the density of the liquid 11 so that the film body 21A faces the free surface 12 of the liquid 11.
The tension means 23 includes a tension film 23a and a plurality of ropes 23b. One end of the tension film 23a is connected to an intermediate portion of the film body 21A, and the other end is connected to the rope 23b. To the bottom surface of the tank 10. Here, the intermediate portion in the film body 21A does not have to be a center position that is bilaterally symmetric as shown in the drawing, and it is only necessary to be positioned between both end portions of the film body 21A. The tension film 23a may have the same width as the film body 21A or a width shorter than the film body 21A, and may be constituted by a part of the film body 21A, or may be connected to another member.
The float 24 according to the present embodiment is also arranged at the center of the film body 21A. On the other end side of the rope 23b, a tension changing means 25 for changing the length of the rope 23b according to the height of the free surface 12 of the liquid 11 is provided. Further, the other end of the rope 23b is provided with a buffer means 26 for reducing the impact load.

The operating state of the sloshing load reducing device according to the present embodiment will be described with reference to FIG.
FIG. 4 is a behavior diagram during tuning of the sloshing load reducing device according to the present embodiment.
As shown in FIG. 4, in the one-end-side film body 21Ax, the support means 22a follows the deformation of the free surface 12 due to the movement of the liquid 11 with the support position restricting means 22c as a fulcrum. At the same time, the tension film 23a is deformed by the flow of the liquid 11 and suppresses the vertical movement of the one end side film body 21Ax. When the tension film 23a is deformed, the rope 23b is tensioned and an impact load is generated in the axial direction. The tension film 23a suppresses the flow X of the liquid 11 in the left direction by changing it to the flow Y in the vertical direction, deforms the other end side film body 21Ay, and the flow X of the liquid 11 in the left direction. It has a function as an adjustment means.

As described above, according to the present embodiment, when the film body 21A changes following the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension film 23a and the rope 23b. Therefore, the flow of the liquid 11 can be suppressed and the fluctuation of the free surface 12 can be reduced.
Further, since the membrane body 21A is set longer than the length of the tank 10 and the tension film 23a is disposed below the middle portion of the film body 21A, the tank 10 is not applied with an excessive force on the tension film 23a. The flow of the liquid 11 that moves inside can be suppressed.
In addition, by pulling the tension film 23a with the rope 23b, the degree of freedom of deformation of the film body 21A and the tension film 23a can be controlled.
Further, by setting the buoyancy of the film body 21A in relation to the density of the liquid 11, the film body 21A can be made to face the free surface 12 of the liquid.
In addition, by providing the float 24 so as to form a convex shape on the upper surface of the film body 21A, the movement of the liquid 11 running on the upper surface of the film body 21A can be suppressed.
Further, by providing the tension changing means 25, the film body 21 </ b> A can face the height of the free surface 12 of the liquid 11 according to the amount of the liquid 11 stored in the tank 10.
Further, by providing the support position adjusting means 22b, the film body 21A can follow the liquid surface even when the free surface 12 of the liquid 11 is greatly shaken, and it is possible to limit the excessive force applied to the film body 21A. .
Further, by restricting the upper limit position and the lower limit position of the support means 22a by the support position restricting means 22c and 22d, it is possible to prevent the film body 21A from colliding with the tank 10 while reducing the fluctuation of the free surface of the liquid. Can do.
Further, by stretching the film body 21A with the ropes 23b provided at a plurality of locations, the degree of freedom of deformation of the film body 21A and the tension film 23a according to the deformation of the free surface 12 can be controlled.
Further, by providing the buffering means 26, the impact on the film body 21A itself, the tension film 23a and the rope 23b caused by the movement of the film body 21A can be reduced.
In addition, you may provide the tension | pulling film | membrane 23a in this embodiment in the intermediate part of the film body 21 in 1st Embodiment. Moreover, it can also comprise only the tension | pulling film | membrane 23a, without using the rope 23b.
Moreover, you may comprise by the film | membrane which has a stretching property as the film body 21A in this embodiment. Even when the stretchable film body 21 </ b> A is used, it may be set longer than the length of the tank 10 or may be the same length as the tank 10. Furthermore, in the case of using the stretchable film body 21 </ b> A, it may be installed with a predetermined tension using a material shorter than the length of the tank 10.

The third embodiment of the sloshing load reducing device of the present invention will be described below.
5A is a cross-sectional view showing the sloshing load reducing device according to the present embodiment, FIG. 5B is a view taken along the line AA in FIG. 5A, and FIG. 5C is FIG. 5B. It is a BB arrow line view. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
The sloshing load reducing device according to this embodiment is suitable when the tank 10A has a long dimension in the width direction as well as the length direction.
In the sloshing load reducing device according to the present embodiment, the film body 21B is set longer than the length and width of the tank 10A, but the intermediate portion of the film body 21B is not submerged in the liquid 11. The buoyancy of the film body 21B is set in relation to the density of the liquid 11 so that the film body 21B faces the free surface 12 of the liquid 11.
As in the second embodiment, the tension means 23 uses a tension film 23a and a plurality of ropes 23b, but the two tension films 23a are arranged so as to cross each other. The tension film 23a has the same width or the same length as the film body 21B, or a width or a shorter length than the film body 21B, and is constituted by a part of the film body 21B, or another member connected thereto. But you can.
According to this embodiment, even in the tank 10A having a large dimension not only in the length direction but also in the width direction, the same effect as in the above embodiment can be obtained.
In addition, you may loosen the intermediate part of the film body 21B in this embodiment like 1st Embodiment.
Moreover, you may comprise by the film | membrane which has a stretching property as the film body 21B in this embodiment. Even when the stretchable film body 21B is used, it may be set longer than the length of the tank 10A or may be the same as the length of the tank 10A. Further, when the stretchable film body 21B is used, it may be installed with a predetermined tension using a material shorter than the length of the tank 10A.

The fourth embodiment of the sloshing load reducing device of the present invention will be described below.
FIG. 6 is a sectional view showing the sloshing load reducing device according to the present embodiment. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, a film body 21C having elasticity is used instead of the film body 21 in the first embodiment. Therefore, as illustrated, the film body 21 </ b> C is not submerged in the liquid 11 by slackening the intermediate portion downward. Also in the film body 21 </ b> C, the buoyancy of the film body 21 </ b> C is set in relation to the density of the liquid 11 so as to face the free surface 12 of the liquid 11.
In this embodiment, a case where a plurality of ropes are used as the tension means 23 is shown. However, as shown in the second embodiment, as the tension means 23, a tension film 23a and a plurality of ropes 23b are used. May be used.
According to the present embodiment, when the film body 21C fluctuates following the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension means 23, so that the flow of the liquid 11 is suppressed. Thus, the fluctuation of the free surface 12 can be reduced.
Also in the present embodiment, although the degree varies depending on the stretchability of the film body 21C, the film body 21C is deformed downward by the tension means 23 as in FIG. 2, and the flow of the right liquid to the left side is reduced. Is done.

The fifth embodiment of the sloshing load reducing device of the present invention will be described below.
FIG. 7 is a cross-sectional view of a main part of the sloshing load reducing device according to the present embodiment. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, a film body 21A is used instead of the film body 21C in the fourth embodiment, and an elastic member 31 is provided between the film body 21A and the support means 22a.
In addition, you may provide the elastic member 31 in the film body 21C in 4th Embodiment.
Also, in this embodiment, a case where a plurality of ropes are used as the tension means 23 is shown. However, as shown in the second embodiment, as the tension means 23, a tension film 23a and a plurality of ropes 23b are used. May be used.
According to the present embodiment, when the film body 21A changes following the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension means 23, so that the flow of the liquid 11 is suppressed. Thus, the fluctuation of the free surface 12 can be reduced.
Also in the present embodiment, although the degree varies depending on the elasticity of the elastic member 31, the film body 21A is deformed downward by the tension means 23 as in FIG. 2, and the flow of the right liquid to the left is reduced. obtain.

The sixth embodiment of the sloshing load reducing device of the present invention will be described below.
FIG. 8 is a cross-sectional view of a main part of the sloshing load reducing device according to the present embodiment. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, a film body 21A is used instead of the film body 21C in the fourth embodiment, and a loose film body 32 is provided separately between the film body 21A and the support means 22a.
Also, in this embodiment, a case where a plurality of ropes are used as the tension means 23 is shown. However, as shown in the second embodiment, as the tension means 23, a tension film 23a and a plurality of ropes 23b are used. May be used.
According to the present embodiment, when the film body 21A changes following the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension means 23, so that the flow of the liquid 11 is suppressed. Thus, the fluctuation of the free surface 12 can be reduced.
Also in the present embodiment, the film body 21A is deformed downward by the tension means 23 as in FIG. 2, and the flow of the right liquid to the left side is reduced.

The seventh embodiment of the sloshing load reducing device of the present invention will be described below.
FIG. 9 is a cross-sectional view of a main part of the sloshing load reducing device according to the present embodiment. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
In this embodiment, the film body 21 in the first embodiment is used, but two intermediate portions are provided in the longitudinal direction that are slackened downward and immersed in the liquid 11. As described above, the film body 21 may be stretched by the stretching means 23 provided at a plurality of locations so as to form a plurality of intermediate portions to be submerged in the liquid 11.
In this embodiment, a case where a plurality of ropes are used as the tension means 23 is shown. However, as shown in the second embodiment, a tension film 23a and a plurality of ropes 23b are used as the tension means 23. May be used.
According to the present embodiment, when the film body 21 follows the deformation of the free surface 12 due to the movement of the liquid 11, the intermediate portion is restrained by the tension means 23, so that the flow of the liquid 11 is suppressed. Thus, the fluctuation of the free surface 12 can be reduced.

Below, embodiment of a ship with a sloshing load mitigation device of the present invention is described.
FIG. 10A is a top cross-sectional view of the main part of the ship with the sloshing load reducing device according to the present embodiment, and FIG. 10B is a side cross-sectional view of the main part of the ship. The same members as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
This embodiment shows the case where the sloshing load reducing device according to the first embodiment is applied to a ship except for the arrangement of the float 24.
The float 24 in this embodiment includes floats 24a and 24b having different lengths.
By arranging as in the present embodiment, the pitching angle of the ship 40 is generally smaller than the rolling angle, and the oscillation of the liquid 11 in the tank 10 is reduced, and even when the tank 10 is particularly long. Sloshing can be effectively prevented.
Note that the sloshing load reducing device can be provided in a direction in which sloshing easily occurs regardless of the arrangement direction of the tank with respect to the ship. Further, as the sloshing load reducing device in the present embodiment, the sloshing load reducing device described in the embodiments other than the first embodiment can be applied.
Further, the sloshing load reducing device in the present embodiment can be used for a ship such as an oil tanker, an LNG ship, or an LPG ship. When the liquid 11 in the tank is at a very low temperature like liquefied gas, aramid fibers are suitable for materials such as the membrane body 21, the tension means 23, the tension film 23a, and the rope 23b.
In the above embodiment, when the buoyancy of the film body 21 is set in relation to the density of the liquid 11, the buoyancy is adjusted by forming an air layer in addition to the adjustment by the specific gravity of the film body 21 itself. Also good.
In addition, when the float 24 is provided, it may be formed in the film body 21 in addition to the case where it is attached to the upper surface of the film body 21. The film body 21 and the float 24 may be formed integrally or separately. It may be configured.

  The present invention is suitable for a tank mounted on a ship such as an oil tanker, an LNG ship, or an LPG ship, but a tank provided for a floating body for collecting crude oil and liquid resources, a tank lorry for transporting liquid on land, and a liquid freight train. The present invention can be widely applied to other tanks and liquid storage tanks.

DESCRIPTION OF SYMBOLS 10 Tank 11 Liquid 12 Free surface 21 Film body 22a Support means 22b Support position adjustment means 22c Support position restriction means 22d Support position restriction means 23 Tensioning means 24 Float 25 Tension change means 26 Buffering means

Claims (13)

  A tank for storing the liquid, a film body that faces the free surface of the liquid and has a degree of freedom in the horizontal direction, support means for supporting both ends of the film body in the tank, and the film body in the middle A sloshing load reducing device comprising tension means for pulling downward in the section.   2. The sloshing load reducing device according to claim 1, wherein the film body is set longer than a length of the tank, and the intermediate part of the film body is slackened downward to be submerged in the liquid. .   The sloshing load reducing device according to claim 1 or 2, wherein a rope is used as the pulling means.   The sloshing load reducing device according to claim 1 or 2, wherein a tension film is used as the tension means.   The sloshing according to any one of claims 1 to 4, wherein the buoyancy of the film body is set in relation to the density of the liquid so that the film body faces the free surface of the liquid. Load reducing device.   6. The sloshing load reducing device according to claim 5, wherein a float that gives buoyancy to the film body is provided so as to form a convex shape on an upper surface of the film body.   The sloshing load according to any one of claims 1 to 6, further comprising tension changing means for changing a length of the tension means according to a height of the free surface of the liquid. Mitigation device.   The sloshing load according to any one of claims 1 to 7, further comprising: a support position adjusting unit that changes a vertical position of the support unit according to deformation of the free surface due to the movement of the liquid. Mitigation device.   The sloshing load reducing device according to claim 8, wherein an upper limit and / or a lower limit of the support means are regulated by the support position adjusting means.   The sloshing load reducing device according to any one of claims 1 to 9, wherein the film body is stretched by the stretching means provided at a plurality of locations.   The sloshing load reducing device according to any one of claims 1 to 10, wherein the tension means further includes a buffer means for reducing an impact load.   A ship with a sloshing load reducing device, comprising the sloshing load reducing device according to any one of claims 1 to 11.   The ship with a sloshing load reducing device according to claim 12, wherein the tank is arranged so that a length direction of the tank is a ship length direction or a ship width direction.