JP2007168889A - Sloshing suppressing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sloshing suppressing device which suppresses the generation of sloshing, and at the same time, can smoothly lower a floating roof by neither receiving a resistant force from a liquid nor lifting the floating roof from the liquid surface accompanying a fall of the liquid surface. <P>SOLUTION: This sloshing suppressing device includes: at least four plate members 20; and at least four hinge devices 21 which form a cylindrical body by connecting respective end sections of the at least four plate members 20 with each other, and make angles which are formed by the connected plate members respectively changeable. At least one of the at least four hinge devices 21 is connected with the lower surface of the floating roof, and a load is applied to the floating roof, and at least one of the at least four plate members 20 is equipped with a window 22 which enables a liquid in the cylindrical body to flow out. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for suppressing occurrence of sloshing, which is used in a container having a floating roof that floats on a liquid surface and covers the liquid surface.

  Various tanks are built to store oil and store butane, gasoline, naphtha, light oil, heavy oil, etc. that are refined from oil. For example, a fixed-roof tank where the roof covering the top of the container is a fixed roof, a floating-roof tank where the roof moves as the liquid level changes, and a spherical holder is built for butane and naphtha, which are highly volatile. ing. These tanks are covered at the top in order to suppress the emission into the atmosphere due to the volatilization of a volatile liquid. Although the fixed roof type tank is provided with a fixed roof, there is a space between the fixed roof and the liquid surface, and evaporated gas accumulates in the space, resulting in liquid loss. This liquid loss reduces the amount of oil stored, butane stored, and the like. Accordingly, many floating roof tanks have been constructed in recent years that make it possible to reduce the liquid loss by eliminating the space in contact with the liquid surface. The floating roof of the floating roof type tank is composed of a deck plate that covers the liquid surface and a pontoon that is a box-shaped structure provided at the edge of the deck plate.

  The floating roof rises as the liquid level rises due to the supply of oil or the like into the tank, and falls as the liquid level falls due to the removal of oil or the like from the tank. Also, it swings as the liquid level swings during an earthquake. When the period of shaking due to the earthquake is close to the natural period of the container, resonance occurs, and this resonance causes sloshing in which the liquid level in the tank greatly swells. Although the upper part is usually covered with a floating roof, the liquid level is released and the liquid overflows from the tank due to the large wave of liquid level caused by this sloshing during an earthquake. Petroleum and the like are flammable liquids, and if there is an ignition source such as static electricity in the overflowing liquid, a large fire is generated. Therefore, it is desired to provide an apparatus for suppressing the occurrence of sloshing.

  In order to suppress the occurrence of sloshing, there is a method of attaching a weight to the lower surface of the floating roof so that the floating roof does not easily fluctuate with the displacement of the liquid level. However, depending on the shape of the weight, there is a problem that the floating roof does not drop further when the liquid level is lowered, and the advantage of adopting the floating roof that suppresses liquid loss cannot be obtained. Therefore, a flat weight can be used so that the floating roof can be lowered sufficiently, but the flat weight receives a buoyancy and cannot effectively prevent sloshing. It was.

  As an apparatus capable of effectively suppressing the occurrence of sloshing, for example, including a linear body suspended from the lower surface of the floating roof, and a resistance plate formed by connecting a pair of plate-like bodies in a tiltable manner, An apparatus has been proposed in which a resistive plate is suspended and supported on a linear body so that the plate-like body can be tilted only in a direction of closing upward from a state where the plate-like body is developed substantially horizontally (see Patent Document 1). When the floating roof swings upward, each plate-like body of the resistance plate develops substantially horizontally and receives a resistance force from the stored liquid, thereby suppressing the swinging of the floating roof. Thereby, sloshing is calmed down quickly.

In this device, since each plate-like body is in a state of being developed almost horizontally, the floating roof can be sufficiently lowered even when the liquid level is lowered, but each plate-like body is moved upward as the liquid level is lowered. If each plate-like body tilted in the closing direction and tilted at a certain liquid surface position comes into contact with the floating roof, and the liquid level drops below that level, each plate-like body must also be deployed substantially horizontally. Regardless, since it receives resistance from the stock solution, it does not develop easily, and there is a problem that evaporation occurs during that time, resulting in liquid loss.
JP-A-9-142575

  The present invention has been made to solve the above-described problem, and can suppress the occurrence of sloshing during an earthquake, and the floating roof can be lifted from the liquid surface without receiving resistance from the liquid. An object of the present invention is to provide a sloshing suppression device that can be smoothly lowered as the liquid level is lowered and that can sufficiently be lowered until the floating roof is close to the bottom of the container.

  In the present invention, end portions of four plate members are connected to each other by a hinge device to form a cylindrical body, and the liquid in the cylindrical body can flow out to one of the four plate members. A structure having a window, and by attaching the device of this configuration to the lower surface of the floating roof, the device functions as a weight, the liquid level is lowered, and the hinge device even when the device contacts the bottom of the container In addition, it is made by finding that the floating roof can be sufficiently lowered without flowing out of the liquid level without receiving resistance from the liquid by flowing out the liquid inside and smoothly deforming it. It is a thing. The above-mentioned subject is achieved by providing the sloshing suppression device of the present invention.

  The sloshing suppression device of the present invention can form at least four plate members and end portions of at least four plate members to form a cylindrical body, and each angle formed by the connected plate members can be changed. And at least one of the at least four hinge devices connected to the lower surface of the floating roof to apply a load to the floating roof, and to at least one of the at least four plate members A window that allows the liquid in the cylindrical body to flow out is provided.

  Moreover, it is preferable that at least three sloshing suppression devices of the present invention are connected to the edge of the lower surface of the floating roof at equal intervals. This is to apply a load evenly to the floating roof so that the floating roof does not tilt.

  It is preferable that both end portions of the at least four plate members have a constant curvature corresponding to the circular arc of the floating roof. This is because the sloshing suppression device can be mounted at a distance from the center of the circular floating roof, and a load can be applied effectively. Moreover, by making it into the shape which has a fixed curvature, the corner | angular part of a board member can be prevented from being caught on the inner wall of a container during a liquid level fall, and the situation where a floating roof does not fall can be prevented. .

  In the sloshing suppression device of the present invention, for example, at least one of at least four plate members, that is, the plate member on which the window is formed can be a punching plate on which a plurality of holes are formed.

  The floating roof may be composed of a circular steel plate and a box-shaped structure that is connected to the edge of the steel plate and formed in a hollow and ring shape. It is preferable that at least three sloshing suppression devices of the invention are provided at equal intervals on the lower surface of the box-shaped structure so that a load is evenly applied to the box-shaped structure.

  By providing the sloshing suppression device of the present invention, it is possible to suppress the occurrence of sloshing in the event of an earthquake. The roof can be lowered to a position close to the bottom of the container without lifting.

  The present invention will be described in detail with reference to the drawings, but the sloshing suppression device of the present invention is not limited to the description of the drawings. First, FIG. 1 illustrates a container including a floating roof that contains liquid and floats on the liquid surface and covers the liquid surface.

  The container shown in FIG. 1 is constructed by constructing an accommodating portion for accommodating a liquid from a bottom plate 10 and a side plate 11, and after the liquid is accommodated in the accommodating portion, the floating roof 12 is floated on the liquid surface. For example, the bottom plate 10 is formed of a circular plate having a predetermined thickness, and the side plate 11 is formed in a cylindrical shape by welding to an end portion of the circular plate.

  Examples of the liquid contained in the interior include liquid fuels such as petroleum and heavy oil, water, and the like. After the liquid is stored, the floating roof 12 is floated on the liquid surface. The floating roof 12 includes a circular steel plate 12a that covers the liquid surface, and a pontoon 12b that is a box-shaped structure that is provided around the edge of the steel plate 12a and is formed in a hollow and ring shape. The floating roof 12 has a structure that floats on the liquid surface by a pontoon 12b that is used by being floated. For example, the pontoon 12b can be made by molding a fiber reinforced plastic (FRP) material, concrete, or the like in which glass fiber or carbon fiber is embedded as a reinforcing material.

  The sloshing suppression device 13 of the present invention is attached to the lower surface of the pontoon 12b immersed in the liquid, and functions as a weight for fixing the floating roof 12 so that the liquid level does not wave due to the occurrence of an earthquake or the like. The function as the weight can suppress the undulation of the liquid surface and suppress the occurrence of sloshing where the liquid surface greatly swells due to resonance.

  Further, the sloshing suppression device 13 of the present invention can maintain the floating roof floating on the liquid surface by deforming even when the liquid surface is lowered by taking out the liquid and contacting the bottom plate 10. Liquid volatilization can be suppressed and liquid loss can be suppressed. The sloshing suppression device of the present invention will be described in detail with reference to FIG.

  The sloshing suppression device shown in FIG. 2 forms a cylindrical body by connecting the four plate members 20 and ends of the four plate members 20, and an angle formed by the two plate members 20 connected to each other. 4 is configured to include four hinge devices 21 that can be changed.

  In the sloshing suppression device, one of the four hinge devices 21 is connected to the lower surface of the floating roof 12 shown in FIG. 1 to apply a load toward the bottom of the container. One of the components arranged toward the liquid surface is provided with a window 22 that allows the liquid in the cylindrical body to flow out.

  Specifically, the four plate members 20 and the four hinge devices 21 form a cylindrical body that is a hollow rectangular parallelepiped and whose two opposing surfaces are open to allow liquid to flow in and out. The plate member 20 and the hinge device 21 are fixed by screws or welding as described above. As shown in FIG. 2, the hinge device 21 includes a shaft body 21 a, an insertion hole through which the shaft body 21 a is inserted, and a blade extending in one direction, and is connected to the edge of one plate member 20 and the shaft body 21 a It is comprised from the some connection rotation member 21b which enables rotation as a center. In FIG. 2, one hinge device 21 is composed of one shaft body 21a and six coupled rotating members 21b, and is arranged so as to be interposed between the two plate members 20, and three coupled rotating members 21b. Is fixed to one of the two plate members 20, and the remaining three coupled rotating members 21 b are fixed to the other plate member 20. Thereby, the plate member 20 can be rotated around the shaft body 21a, and the angle formed by the two plate members 20 can be changed.

  The sloshing suppression device shown in FIG. 2 is attached to the lower surface of the pontoon 12b constituting the floating roof 12 shown in FIG. For example, as shown in FIG. 3, four can be attached at equal intervals. By attaching the sloshing suppression devices 13 of the same size and mass so that the two are opposed to each other, a load can be applied evenly to the floating roof 12 without tilting the floating roof 12. Attachment to the pontoon 12b can be performed by fastening one hinge device 21 with a screw or welding. By connecting one hinge device 21 and the pontoon 12b in this manner, the sloshing suppression device 13 can be deformed in the vertical direction with respect to the ground or the bottom plate 10 of the container. Specific deformation will be described later.

  The plate member 20 used for the sloshing suppression device can be a rectangular steel plate having a predetermined thickness. That is, any material may be used as long as it is larger than the density of the liquid and can apply a load to the floating roof 12. The size and thickness can be appropriate depending on the liquid to be accommodated, the capacity of the container, and the like. In addition to the structure shown in FIG. 2, the hinge device 21 may have any structure as long as the angle formed by the two plate members 20 can be changed. An example of the hinge device 21 is a hinge. The hinge device 21 can also be made of a material that is larger than the density of a liquid such as a steel material and that applies a load to the floating roof 12. In FIG. 3, an example in which four sloshing suppression devices 13 are attached to the floating roof 12 is shown, but any number of three or more that can apply a load evenly to the floating roof 12 may be used. .

  Here, the deformation | transformation of a sloshing suppression apparatus is demonstrated with reference to FIG. As shown by a broken line in FIG. 4, when the liquid level of the liquid in the container is at a high level, the sloshing suppression device 13 attached to the floating roof 12 extends in a direction perpendicular to the ground or the bottom plate 10, A load is applied to the floating roof 12 in the direction toward the bottom plate 10. That is, this sloshing suppression device plays the role of a weight, and suppresses the liquid surface from undulating even when an earthquake occurs. When extraction is started from the outlet 14 to use the liquid, the level of the liquid level is lowered, and the floating roof 12 floating on the liquid level is also lowered. When the liquid level drops to a certain level, the sloshing suppression device 13 attached to the lower surface of the floating roof 12 contacts the bottom plate 10 as the floating roof 12 descends.

  Since the sloshing suppression device 13 can change the angle formed by the two plate members 20 by the hinge device 21 shown in FIG. 2, the angle is changed as the liquid level decreases, and extends in the vertical direction. It is transformed from a state to a crushed state. That is, as shown by the solid line in FIG. 4, the floating roof 12 maintains a state of floating on the liquid surface, and the sloshing suppression device 13 holds the contact with the bottom plate 10 while the floating roof 12 and the bottom plate 10 Transforms into a crushed state. In the case of a device composed of only four plate members 20 and four hinge devices 21, the sloshing suppression device 13 is deformed into a crushed state as the liquid level decreases, but the cylindrical body of the sloshing suppression device is filled with liquid. Therefore, it cannot be deformed depending on the liquid level lowering speed, that is, the liquid take-out speed, and the floating roof 12 can be in a state of being separated from the liquid level. This separated state creates a space between the liquid surface and the floating roof 12 and allows the liquid to volatilize, resulting in liquid loss. For this reason, in this invention, it is set as the structure provided with the window 22 in at least one of the four board members 20, The liquid with which a cylindrical body is filled can be discharged by this window 22 with a liquid level fall. Thus, since the sloshing suppression apparatus 13 of this invention discharges | emits the liquid in a cylindrical body and does not produce the said space, it can suppress a liquid loss reliably. The floating roof 12 can be lowered by the hinge device 21 of the sloshing suppression device 13 until the upper and lower plate members 20 are folded.

  FIG. 5 is a diagram showing another embodiment of the sloshing suppression device. FIG. 5A is a side view of an apparatus composed of five plate members 50 and five hinge devices 51, and FIG. 5B is a diagram showing a number of holes in one of the plate members 50. The front view of the apparatus comprised by connecting the punching plate 53 and the plate member 50 with the hinge apparatus 51 using the punching plate 53 provided with 52 is shown, respectively. The device shown in FIG. 5A is configured using a plate member similar to the plate member 20 shown in FIG. 2 and using a hinge device similar to the hinge device 21 shown in FIG. Although not shown in FIG. 5A, at least one plate member 50 is provided with a window that allows the liquid inside to flow out. In this way, by constituting the four or more plate members 50 and the hinge device 51, the device that has been in a vertically extending state when the liquid level is high is crushed as the liquid level decreases. It can be made to change to a state where it has become, and thereby liquid loss at the time of liquid level drop can be suppressed. By the way, in the device composed of three plate members, the rotation by the hinge device is suppressed and the device cannot be deformed. In addition, when one or two plate members are lowered in a state where they extend in the vertical direction, they contact the bottom plate while maintaining the standing state, and the floating plate is formed by the plate member in the standing state. There can be situations where it is supported and cannot be lowered further. Therefore, the sloshing suppression device of the present invention is configured to include four or more plate members 50 and correspondingly four or more hinge devices 51 so that the floating roof can be reliably lowered. In addition, when a sloshing suppression apparatus is comprised by six or more board members and six or more hinge apparatuses, the hinge apparatus connected with a floating roof is not restricted to one, It can be changed into the crushed state. If possible, two adjacent hinge devices may be connected to the floating roof.

  In the present invention, as shown in FIG. 5B, the window can employ a punching plate 53 having a plurality of holes 52. The apparatus shown in FIG. 5B is composed of four plate members and four hinge devices as in the apparatus shown in FIG. 2, but one of the plate members is a punching plate 53 and a plurality of holes 52. Therefore, the outflow of the liquid in the cylindrical body is further facilitated, and the deformation by the hinge device 51 is further facilitated. The punching plate 53 is formed by punching, and the hole 52 is not limited to a circle as shown in FIG. 5B, but may have any shape such as a rectangle or an ellipse. In the present invention, although it is not a plate, a wire cloth, expanded metal, or the like can also be used.

  As the sloshing suppression device, a plurality of plate members may be connected in series using a plurality of hinge devices to constitute a device. However, in this apparatus, although the liquid level decreases as the liquid is taken out, when the plurality of plate members are not folded by the hinge device and are maintained in the extended state, the floating roof is supported thereby, There may be a space between the liquid level. In the present invention, it is necessary to deform as the liquid level lowers and to surely lower the floating roof, and the device of the present invention includes four or more plate members so as to deform reliably as the liquid level decreases. It is composed of four or more hinge devices, and the end portions of the plate members are connected by the hinge device so as to form a cylindrical body.

  FIG. 6 is a view showing still another embodiment of the sloshing suppression device of the present invention. FIG. 6A shows an overall view, and FIG. 6B shows details of the plate member. In the apparatus shown in FIG. 6A, both end portions 61a and 61b of the plate member 60 have a certain curvature corresponding to the circular arc of the circular floating roof. In order to connect the plate members 60 to each other, for example, Two hinge devices 62a and 62b are used. As shown in FIG. 6 (b), one plate member 60 has both end portions 61a and 61b connected using hinge devices 62a and 62b having a certain curvature corresponding to the arc of the floating roof. Thus, the sloshing suppression device can be attached in the vicinity of the inner wall of the container.

  When the position where the sloshing suppression device is attached is separated from the inner wall of the container and is close to the center of the floating roof, the effect as a weight is reduced, and the floating roof becomes unstable and the floating roof is easily inclined. In the sloshing suppression device made of a flat plate as the plate member, the corner portion of the plate member is likely to come into contact with the inner wall of the container and may be locked by the corner portion. Therefore, it must be mounted at a certain distance from the inner wall of the container so as not to come into contact. This reduces the effect as a weight. Therefore, in the present invention, a structure in which both end portions 61a and 61b have a constant curvature as shown in FIG.

  Here, the effect as a weight will be described. The floating roof floats on the liquid surface with its center as a fulcrum, and according to the principle of leverage, a larger load can be applied as the distance from the center increases even if the weight has the same mass. The undulation of the liquid level caused by the occurrence of an earthquake is effectively suppressed by applying a larger load to the floating roof. For these reasons, a structure having the above-described constant curvature that can be attached more apart from the center is preferable.

  In FIG. 6, the plate member arranged on the center side of the floating roof is small, and the plate member arranged on the inner wall side of the container is enlarged. Thus, by enlarging the plate member arranged on the inner wall side of the container, the sloshing suppression device can be smoothly moved along the inner wall without being caught by the inner wall of the container. Since the plate member having a large mass is attached to the separated position, a larger load can be applied to suppress the ripple more effectively, thereby suppressing the occurrence of sloshing. In FIG. 6, the two hinge devices 62 a and 62 b are used to connect the two plate members 60. However, a shaft body having a constant curvature and a plurality of connecting rotating members that can be inserted through the shaft body are provided. It can also be connected by one hinge device provided. As shown in FIG. 6, when two plate members 60 are connected by two hinge devices 62a and 62b, a gap is generated between the two hinge devices 62a and 62b. This gap allows the liquid inside to flow out, and this gap can be used as a window.

The figure which illustrated the container provided with the floating roof for accommodating a liquid and suppressing a liquid loss. The figure which showed one Embodiment of the sloshing suppression apparatus of this invention. The figure which showed the place which attached the several sloshing suppression apparatus to the floating roof. The figure which showed the place where a sloshing suppression apparatus deform | transforms. The figure which showed another embodiment of the sloshing suppression apparatus of this invention. The figure which showed another embodiment of the sloshing suppression apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Bottom plate 11 ... Side plate 12 ... Floating roof 12a ... Steel plate 12b ... Pontoon 13 ... Sloshing suppression device 14 ... Outlet 20 ... Plate member 21 ... Hinge device 21a ... Shaft body 21b ... Connection rotation member 22 ... Window 50 ... Plate member 51 ... Hinge device 52 ... Hole 53 ... Punching plate 60 ... Plate members 61a, 61b ... End portions 62a, 62b ... Hinge device

Claims (5)

An apparatus for containing liquid and used in a container having a floating roof that floats on the liquid surface and covers the liquid surface, and suppresses the occurrence of sloshing,
At least four plate members;
Each of the at least four plate members is connected to each other to form a cylindrical body, and at least four hinge devices each capable of changing the angle formed by the connected plate members;
At least one of the at least four hinge devices is connected to a lower surface of the floating roof to apply a load to the floating roof, and the liquid in the cylindrical body is applied to at least one of the at least four plate members. A sloshing suppression device, comprising a window that allows spillage.   The sloshing suppression device according to claim 1, wherein at least three sloshing suppression devices are connected at equal intervals to an edge of the lower surface of the floating roof.   3. The sloshing suppression device according to claim 1, wherein both end portions of each of the at least four plate members have a constant curvature corresponding to the circular arc of the floating roof.   The sloshing suppression device according to any one of claims 1 to 3, wherein at least one of the at least four plate members is a punching plate in which a plurality of holes are formed. The floating roof is composed of a circular steel plate and a box-shaped structure that is connected to an edge of the steel plate and is formed in a hollow and ring shape, and is used by being floated. The sloshing suppression device according to any one of claims 1 to 4, wherein at least three are provided at equal intervals on a lower surface of the box-shaped structure so that the load is equally applied to the structure.

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