JP4895617B2 - Sloshing suppression device - Google Patents

Description

  The present invention relates to a sloshing suppression device that is used in a container that contains a liquid, covers a liquid surface, and includes a floating roof that floats on the liquid surface and suppresses the occurrence of sloshing.

  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 tank, resonance occurs, and this resonance causes sloshing in which the liquid level in the tank is greatly waved. 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 an overflowing liquid has an ignition source such as static electricity, a fire is generated. Therefore, it is desired to provide a device for suppressing sloshing.

  For example, a direction 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, and each plate-like body is closed upward from a state of being developed substantially horizontally. An apparatus has been proposed in which a resistance plate is suspended and supported on a linear body so that it can be tilted only to the right (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 can suppress the occurrence of sloshing, and when the liquid is taken out, the floating roof is lowered smoothly without separating the floating roof from the liquid level as the liquid level decreases, and the liquid level is lowered. It aims at providing the sloshing suppression apparatus which can be functioned as a floating roof.

  As a result of intensive studies, the present inventors have provided a first hole in the center part, and a plurality of second holes having a smaller diameter compared to the first hole, radially from the center part toward the edge part. And a connecting member for suspending and supporting the plate member on the floating roof, the container is swung by the occurrence of an earthquake, and the container The liquid starts to oscillate with the oscillation of the liquid and tries to generate a wave on the liquid surface. However, the liquid has no choice but to pass through the first hole and the plurality of second holes of the plate member. As a result, it was found that the occurrence of sloshing is suppressed. Further, as the liquid level is lowered due to the liquid being taken out, the connecting member is bent by the joint, and the liquid is effectively allowed to flow out from the first hole in the center, so that the floating roof is lowered smoothly to a low liquid level. Found that it can function as a floating roof. Therefore, the said subject can be achieved by providing the sloshing suppression apparatus of this invention.

  As described above, the sloshing suppression device of the present invention is provided with the first hole in the center portion, and has a plurality of second holes having a smaller diameter than the first hole from the center portion toward the edge portion. It includes a plate member provided with a hole, and a connecting member that includes a joint portion that can be bent and supports the plate member while being suspended from the floating roof.

  The connecting member including the joint portion that can be bent includes a first rod-like member provided with insertion holes at both ends, and a second rod-like member provided with insertion holes at both ends. A first pin joint portion that is fitted into an insertion hole provided in a projecting portion projecting on the lower surface of the roof and an insertion hole provided in one end of the first rod-like member, and joins the first rod-like member rotatably; The second rod is inserted into the insertion hole provided at the other end of the first rod-shaped member and the insertion hole provided at the one end of the second rod-shaped member, and joins the first rod-shaped member and the second rod-shaped member rotatably. The second rod-shaped member is inserted into the pin joint portion, the insertion hole provided in the projecting portion protruding from the upper surface of the plate member facing the floating roof, and the insertion hole provided in the other end of the second rod-shaped member. And a third pin joint portion that is rotatably joined.

  The plurality of second holes are preferably provided so as to be arranged radially from the central portion toward the edge portion. As the container swings, the liquid tends to wave so that the displacement increases toward the edge with the center as the center. For this reason, by providing the plurality of second holes so as to be radially arranged, an appropriate amount of liquid is allowed to pass therethrough and an appropriate resistance is given to the liquid, thereby suppressing occurrence of sloshing.

  It is more preferable that the plurality of second holes are provided so as to be radially arranged from the central portion toward the edge, and further, the diameter is decreased from the central portion toward the edge. This is because the force that the liquid tends to move in the vertical direction increases toward the edge, so that the resistance of the second hole can be reduced by reducing the diameter of the second hole and reducing the amount of liquid that passes therethrough. it can.

  By providing the sloshing suppression device of the present invention, it is possible to effectively suppress the sloshing phenomenon of the floating roof due to long-period earthquakes, and the connection member bends as the liquid level drops when the liquid is taken out. The floating roof can be lowered to a sufficiently low liquid level while the floating roof is floated on the liquid level, and liquid loss can be suppressed.

  The sloshing suppression device of the present invention is used for a container provided with a floating roof that covers the liquid surface and floats on the liquid surface to suppress the volatilization of the liquid. Prior to describing the sloshing suppression device of the present invention, a container having a floating roof will be described with reference to FIG. As shown in FIG. 1, a container having a floating roof includes a container main body including a bottom plate 10 and a side plate 11, and a floating roof 12 that contains liquid in the container main body and floats on the liquid surface to cover the liquid surface. Is done. The container body is formed in a cylindrical shape so that pressure is evenly applied to the side plate 11. The floating roof 12 includes, for example, a steel plate 12a and a pontoon 12b that is a box-shaped structure that is provided around the steel plate 12a and is used by being floated. The pontoon 12b is hollow inside. Since an actual pontoon is a floating structure and its apparent unit volume weight is smaller than that of water, it floats on the liquid surface because the specific gravity of the constituent material is hollow even if it is greater than 1 of the reference material water. Can do. For example, steel is mainly used, but it may be made of plastic materials such as polyvinyl chloride and fiber reinforced plastic (FRP). A seal member (not shown) is provided around the pontoon 12b. The seal member completely covers the liquid surface and prevents the liquid from volatilizing. In FIG. 1, a ring-shaped pontoon 12 b is connected to the periphery of a circular steel plate 12 a to constitute a floating roof 12. The liquid can be taken out through the outlet 13.

  Since the floating roof 12 floats on the liquid surface and covers the liquid surface, the volatilization of the liquid can be suppressed. Moreover, since it is not fixed to the container main body, it can be lowered or raised as the liquid level is lowered or raised during liquid extraction or injection. When an earthquake occurs, the container body swings and the liquid level undulates accordingly. When the period of shaking due to the earthquake is close to the natural period of the container, resonance occurs, and sloshing in which the liquid level in the container greatly swells due to this resonance. In a container having such a floating roof 12, when sloshing occurs, the floating roof 12 is inclined so that the liquid surface is exposed to the atmosphere, and the liquid inside flows out of the container to contaminate soil or rivers. In the case of a flammable liquid, a fire is generated due to the presence of an ignition source such as static electricity.

  The sloshing suppression device of the present invention is used in a container having a floating roof 12 as shown in FIG. 1 and is used by being attached to the floating roof 12 to suppress the swell of the liquid level when an earthquake occurs, thereby reducing the sloshing. It is a device that suppresses the occurrence. By attaching this sloshing suppression device, the liquid inside the container does not flow out of the container.

  The sloshing suppression device of the present invention will be described in detail with reference to FIGS. FIG. 2 shows a front view of the sloshing suppression device attached to the lower surface of the floating roof. FIG. 3 illustrates a plan view of a plate member used in the sloshing suppression device, and FIG. 4 illustrates a connection member used in the sloshing suppression device. 3 and 4 illustrate the plate member and the connection member, and the plate member and the connection member used in the sloshing suppression device of the present invention are not limited to these.

  As shown in FIG. 2, the sloshing suppression device of the present invention includes a plate member 20 immersed in a liquid in a container, and a connection member 30 for supporting the plate member 20 by suspending it from the floating roof 12. Is done.

  The plate member 20 is a circular plate having a predetermined thickness, and is provided with a first hole at the center and a plurality of second holes from the center toward the edge. Here, since the container main body is cylindrical, the plate member 20 is a circular plate. However, if the portion of the container main body that stores the liquid is rectangular, the container main body liquid is stored as a rectangle. It can change according to the shape of the part to do. Since the plate member 20 is suspended and supported by the floating roof 12 by a connecting member 30 described later, it also functions as a weight, but an earthquake occurs and the container tends to move toward the liquid level when the container swings. By moving the liquid through the first hole and the plurality of second holes to give resistance, movement toward the liquid surface is suppressed. Moreover, the liquid which is going to move toward the bottom plate 10 is allowed to pass through the first hole and the plurality of second holes and is given resistance, thereby suppressing the movement toward the bottom plate 10. In general, the displacement of the liquid level accompanying the swinging of the container is small at the center and increases toward the edge. The plate member 20 is provided with a plurality of second holes having a smaller diameter than the first hole from the central portion toward the edge portion, and the movement of the liquid is effectively suppressed by the second holes having the smaller diameter. This suppresses the generation of waves.

  The connection member 30 is used to suspend and support the plate member 20 from the floating roof 12 and includes a joint portion 31 that can be bent. By suspending and supporting the plate member 20, as described above, it is possible to give resistance to the liquid that allows only a predetermined amount of liquid to pass and moves in the vertical direction. Further, when the liquid is taken out, even if the liquid level is lowered and the plate member 20 reaches the bottom plate 10, the connecting member 30 bends to function as a floating roof 12 that suppresses liquid loss and floats. The roof 12 can be lowered to a low liquid level. Further, while the floating roof 12 is being lowered, the liquid surrounded by the bottom plate 10, the side plate 11, and the plate member 20 flows out through the first hole having a large diameter at the center portion. It can be lowered smoothly.

  The plate member will be described in detail with reference to FIG. The plate member 20 is formed slightly smaller than the inner diameter of the container so that the edge portion is adjacent to the inner wall of the container. The plate member 20 is provided with a first hole 21 at the center and a plurality of second holes 22 from the center toward the edge. In the embodiment shown in FIG. 3, the plurality of second holes 22 are provided so as to be arranged radially from the center portion toward the edge portion. Further, a plurality of protrusions 23 having insertion holes are provided so as to be supported by being suspended by the connection member 30 shown in FIG. In FIG. 3, one row is formed by three protrusions 23, one row is rotated 90 °, one row is rotated 90 °, and another 90 ° is rotated 90 °. One row is formed at the rotated position, and is arranged so as to form a total of four rows so that the load of the plate member is equally applied to the floating roof.

  When an earthquake occurs, seismic waves spread concentrically from the epicenter. For a container installed at a certain point, a seismic wave is transmitted in the direction from the epicenter to the container. When the container is swung by this seismic wave, a wave is generated in the direction in which the seismic wave travels. When this wave generated on the liquid surface coincides with the natural frequency of the liquid, the displacement is small at the center of the liquid surface, and the displacement increases toward the edge. At these edges at this point, the liquid level is highest and lowest, respectively. The edge that generates such a bottom liquid level, the center, and the edge that generates the highest liquid level are located on the same straight line in the direction in which the seismic wave travels.

  In order to reduce the liquid level displacement and prevent the wave from being generated, it is preferable to provide the second hole 22 at a position where the maximum displacement is generated in order to minimize the liquid level displacement. For this reason, it is desirable that the plurality of second holes 22 be provided so as to be arranged along the same straight line.

  Earthquakes do not always originate from the same epicenter. For this reason, the direction in which the seismic wave travels depends on the location of the epicenter. However, since the edge that generates the highest liquid level, the center, and the edge that generates the lowest liquid level are located on the same straight line, the second hole 22 is formed along the same straight line although the directions are different. If they are arranged so as to be arranged, the liquid level displacement can be minimized. Therefore, as shown in FIG. 3, by using the plate member 20 provided so that the plurality of second holes 22 are arranged radially, the liquid level displacement can be reduced regardless of the direction of the seismic wave. This can suppress the occurrence of sloshing.

  With reference to FIG. 3, the plate member provided with the second holes so as to be arranged radially has been described. However, in the present invention, if the liquid level displacement can be appropriately suppressed, the plate members are arranged radially. It may not be provided, and in order to suppress it more effectively, the diameter of the second hole can be reduced toward the edge where the liquid level displacement increases, and a larger resistance can be given. In addition, the shape and diameter of the 1st hole 21 and the some 2nd hole 22 can be made appropriate according to the shape and diameter of a container.

  Next, with reference to FIG. 4, the connection member which connects a floating roof and a board member is demonstrated in detail. 4A shows a front view of the connecting member, and FIG. 4B shows a side view of the connecting member. As shown in FIG. 4, the lower surface of the floating roof is provided with a protruding portion 12 c provided with an insertion hole into which a pin can be inserted, and the same protrusion is also formed on the upper surface of the plate member 20 facing the lower surface of the floating roof. A portion 23 is provided. The connecting member 30 includes a first rod-like member 32 provided with insertion holes at both ends, and a second rod-like member 33 provided with insertion holes at both ends. A first pin joint portion that is fitted into an insertion hole provided in the protruding portion 12c protruding from the lower surface of the first rod-like member 32 and an insertion hole provided in one end of the first rod-like member 32, and joins the first rod-like member 32 rotatably. 34 and an insertion hole provided at the other end of the first rod-shaped member 32 and an insertion hole provided at one end of the second rod-shaped member 33, and the first rod-shaped member 32 and the second rod-shaped member 33 are The second pin joint part 35 that is rotatably joined, the insertion hole provided in the projecting part 23, and the insertion hole provided in the other end of the second rod-shaped member 33 are inserted and rotated. It is configured to include a third pin joint portion 36 that can be joined.

  As shown in FIG. 4, the connection member 30 includes a first pin joint 34, a second pin joint 35, and a third pin joint 36, and the connection member 30 can be bent by these pin joints. . For example, the first rod-shaped member 32 is rotated in one direction with the first pin joint portion 34 as a fulcrum, and the second rod-shaped member 33 is moved in the opposite direction with the second pin joint portion 35 as a fulcrum while the first rod-shaped member 32 is fixed. Rotate. In this case, the second rod-shaped member 33 rotates with the third pin joint portion 36 as a fulcrum. Thereby, the connection member 30 bends in the shape of a letter, makes the plate member 20 close to the floating roof, and can function as a floating roof to a sufficiently low liquid level.

  In the embodiment shown in FIG. 4, the portion provided with the insertion holes at both ends of the first rod-like member 32 and the second rod-like member 33 has an expanded structure so as to have substantially the same strength as the central portion. In the first pin joint 34, the second pin joint 35, and the third pin joint 36, for example, both ends of a pin made of a thin rod are threaded, and after inserting into the respective insertion holes, a nut is screwed. By combining, each can be joined. In addition, after inserting into each insertion hole, an expansion member or the like larger than the diameter of the insertion hole is welded to both ends, and each pin joint portion can be configured so that each pin does not come off. In addition, each pin joint part can be inserted in each insertion hole, the 1st rod-shaped member 32 and the 2nd rod-shaped member 33 can be rotated by using the pin joint as a fulcrum, and the plate member 20 is suspended on the floating roof. Any kind of pin structure (for example, a ball joint) and any diameter and length pins may be used as long as they have a strength capable of being lowered and supported.

  So far, the sloshing suppression device has been described in detail with reference to the drawings, but the sloshing suppression device of the present invention is not limited to the embodiment shown in the drawings, and the plate member allows liquid to pass through. As long as the structure can provide resistance, the holes may have any size, shape, arrangement, and number. Further, the connecting member may have a bellows structure, for example, in addition to the pin joint portion as shown in FIG. Furthermore, the connecting member is composed of two rod-shaped members, three pins and three or more rod-shaped members in addition to the pin and the fixing member such as the nut or the expansion member that is fixed so that they are not detached. It may be composed of four or more pins and a fixing member, and the rod-shaped member is an elongated flat plate member having insertion holes provided at both ends in addition to a rod member having insertion holes provided at both ends. There may be.

The figure which illustrated the container provided with a floating roof. The figure which showed the place which attached the sloshing suppression apparatus of this invention to the floating roof. The figure which illustrated the board member used for the sloshing suppression device of the present invention. The figure which illustrated the connection member used for the sloshing suppression device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Bottom plate 11 ... Side plate 12 ... Floating roof 12a ... Steel plate 12b ... Pontoon 12c ... Projection part 13 ... Outlet 20 ... Plate member 21 ... First hole 22 ... Second hole 23 ... Projection part 30 ... Connection member 31 ... Junction 32 ... 1st rod-shaped member 33 ... 2nd rod-shaped member 34 ... 1st pin junction part 35 ... 2nd pin junction part 36 ... 3rd pin junction part

Claims (2)

A sloshing suppression device for covering a liquid surface and being used for a container having a floating roof that floats on the liquid surface, for suppressing the occurrence of sloshing,
A plate member provided with a plurality of second holes having a small diameter compared to the first hole from the center part toward the edge part, provided with a first hole in the center part;
Comprises a joint which allows the bending, seen including a connecting member for supporting hanging said plate member to the floating roof,
The sloshing, wherein the plurality of second holes are provided so as to be radially arranged from the central portion toward the edge portion, and the diameter is reduced from the central portion toward the edge portion. Suppression device. The connection member including the joint portion that enables the bending is provided.
A first rod-like member provided with insertion holes at both ends;
A second rod-like member provided with insertion holes at both ends,
The joint is
A first pin that is fitted into an insertion hole provided in a projecting portion that projects from the lower surface of the floating roof and an insertion hole provided at one end of the first rod-like member, and rotatably joins the first rod-like member. A junction,
The first rod-shaped member and the second rod-shaped member are rotatable by being inserted into an insertion hole provided at the other end of the first rod-shaped member and an insertion hole provided at one end of the second rod-shaped member. A second pin joint to be joined;
The second rod-shaped member is rotated by being inserted into an insertion hole provided in a protruding portion projecting on the upper surface of the plate member facing the floating roof and an insertion hole provided in the other end of the second rod-shaped member. The sloshing suppression device according to claim 1 including the 3rd pin joined part joined so that it is possible.

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