JP2005320034A - Liquid storage tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid storage tank capable of effectively suppressing sloshing occurred by an earthquake, etc., and having a wave-vanishing which is attached even in a fixed roof type tank or in a floating roof type tank. <P>SOLUTION: In the liquid storage tank to store crude oil, medicines, etc., a guide member 3 is suspended below a roof of a tank, a wave-vanishing member 2 which is vertically movable and rotatable while sliding along the guide member is arranged, and a buoyant member 6 is arranged on the lower side of the wave-vanishing member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid storage tank, and more particularly, to a liquid storage tank provided with a wave-dissipating member that attenuates fluctuations generated on a stored liquid surface.

  Conventionally, liquid storage tanks for crude oil, chemicals, etc., have a fixed roof type tank in which the tank body side wall and the roof are fixed in a cylindrical shape, and a floating roof type tank in which the roof moves up and down while sliding along the tank body side wall. There is.

  In recent years, as a national strategy, it has been promoted to store a predetermined amount of crude oil in advance in the country, and the capacity of one tank has been increased accordingly.

  Moreover, since many earthquakes occur in Japan, it is desirable that the storage tank has a structure that does not break or leak even when an earthquake occurs.

  In general, in a normal liquid storage tank, when a strong vibration is applied to the tank body due to an earthquake or the like, the liquid surface stored in the tank swings and a undulation phenomenon called sloshing occurs. In particular, in a floating roof tank, when the vibration applied to the tank body and the sloshing resonate, the floating roof swings while tilting with a large amplitude. May last for a long time.

  For this reason, due to sloshing or resonance, the tank may be damaged, the floating roof may be greatly inclined, a gap may be formed between the tank body and liquid may leak from the gap.

In addition, a floating roof type storage tank having a structure in which a resistance plate that suppresses the swinging of the floating roof even when sloshing occurs due to an earthquake or the like has already been disclosed. (For example, see Patent Document 1)
JP-A-9-142575 (page 1-7, FIG. 1)

  The larger the tank, the greater the effect of sloshing that occurs in the event of an earthquake, so it is desirable that a large liquid storage tank be provided with a wave-absorbing device.

  Furthermore, as a large-sized storage tank, there are a fixed roof type tank and a floating roof type tank, and it is desirable that the wave-dissipating device can be attached to either tank.

  In particular, in order to store crude oil, naphtha, and the like that are highly volatile and easily flammable, a floating roof tank in which the roof moves up and down is used. The floating roof tank has a structure in which the roof moves up and down integrally with the liquid level as the amount of stored liquid increases and decreases. In normal times, the roof moves in close contact with the liquid level. For this reason, when sloshing occurs, the floating roof swings together with the swinging liquid surface. Therefore, the liquid surface is prevented from swinging and liquid leakage from the sliding portion between the tank body and the floating roof occurs. It is important to prevent this.

  An object of the present invention is to effectively suppress sloshing caused by an earthquake or the like in order to solve the above-mentioned problems, and to be able to be mounted on either a fixed roof tank or a floating roof tank. A liquid storage tank comprising a wave member is provided.

  In order to achieve the above object, an invention according to claim 1 is a liquid storage tank for storing crude oil, chemicals, etc., wherein a guide member is suspended under the roof of the tank, and is slid along the guide member. A wave-dissipating member that can be moved up and down while moving is disposed, and a buoyancy member is disposed so that the wave-dissipating member is located near the liquid surface.

  According to the first aspect of the invention having the above-described configuration, the rotatable wave-dissipating member can be disposed at a predetermined position near the liquid surface, so that even if sloshing occurs due to an earthquake or the like, The rocking can be suppressed while rotating at a rotation speed that matches the magnitude of the rocking of the surface, and the sloshing can be effectively attenuated.

  The invention according to claim 2 is characterized in that the wave-dissipating member includes a rotary blade.

  According to the second aspect of the present invention having the above-described configuration, the rotating blades can be rotated effectively by using the rotation of the liquid surface during sloshing by disposing the rotating blades rotatably. And sloshing can be attenuated.

  The invention according to claim 3 is characterized in that the wave-dissipating member has a configuration in which a rotating blade is provided at a lower portion of a disk.

  According to the third aspect of the invention having the above-described configuration, the sloshing can be attenuated by the resistance of the disc in addition to the attenuation of the sloshing due to the rotation.

  According to a fourth aspect of the present invention, the guide member is disposed in the center of the roof so that the diameter of the wave-dissipating member is about half of the inner diameter of the tank, and the wave-dissipating member is vertically disposed below the guide member. It is characterized in that a stopper is provided to limit the lower limit when moving.

  According to the invention according to claim 4 having the above-described configuration, it is possible to effectively attenuate sloshing by mounting one wave-dissipating member, even when the stored liquid is full or almost empty. .

  According to a fifth aspect of the present invention, a plurality of the guide members are disposed on the roof, and the diameter of the wave-dissipating member is set to such a diameter that adjacent wave-dissipating members do not contact each other, and the lower part of each guide member Further, the present invention is characterized in that a stopper for restricting a lower limit when the wave-dissipating member moves up and down is provided.

  According to the invention concerning Claim 5 which has the above-mentioned composition, a plurality of small wave-dissipating members can be arranged, and sloshing in all places in a tank can be attenuated effectively.

  According to a sixth aspect of the invention, the buoyancy member is a ballast tank-like buoyancy adjustment member capable of pouring and draining, and is characterized in that a buoyancy is adjusted by injecting liquid into the tank.

  According to the invention concerning Claim 6 which has said structure, the arrangement | positioning position of the quenching member with respect to the position of a liquid level can be set to the most effective position.

  The invention according to claim 7 is characterized in that the liquid storage tank is a fixed roof type tank, and the guide member connects the bottom plate of the tank and the roof.

  According to the invention which concerns on Claim 7 which has said structure, while connecting a baseplate and a roof with a guide member, even if it is a large sized fixed roof type tank, while reinforcing the whole tank and effective sloshing It can be set as a liquid storage tank provided with the wave-quenching member which suppresses.

  According to an eighth aspect of the present invention, the liquid storage tank is a floating roof type tank, the guide member is a cylindrical body, and a guide shaft body that slides and guides the guide member is disposed upward from the tank bottom plate portion. It is characterized by having installed.

  According to the invention which concerns on Claim 8 which has said structure, even if it is a large sized floating roof type tank, rocking | fluctuation of a floating roof is prevented by connecting a floating roof and a baseplate with a sliding guide body. In addition, regardless of the height of the floating roof, the disposing position of the wave-dissipating member can be set to an optimum position.

  The invention according to claim 9 is a liquid storage tank for storing crude oil, chemicals, etc., wherein a guide member that penetrates the roof of the tank and reaches the bottom plate is disposed, and a drive motor that rotationally drives the guide member is provided. Installed on the roof, the projecting portion of the guide member projecting on the roof and the drive motor are coupled via a coupling member, and provided in the axial direction of the guide member hanging below the roof A wave-dissipating member having a concave part that engages with the convex part is attached to the guide member so as to be slidable in the axial direction of the guide member and to be rotatable together with the guide member. The buoyancy member is provided so as to be located at the same position, and the drive motor is rotationally driven by a detection signal from a separately installed seismic wave detection means.

  According to the invention according to claim 9 having the above-described configuration, it is detected that an earthquake will occur in the near future and sloshing occurs, and the wave-dissipating member is driven before sloshing occurs to generate and grow sloshing. Can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a fixed roof type tank or a floating roof type tank, a liquid storage tank provided with the wave-dissipating member which suppresses the sloshing which generate | occur | produces by an earthquake etc. effectively can be obtained.

  The purpose of obtaining a liquid storage tank having a wave-dissipating member that can be attached to both a fixed roof tank and a floating roof tank while effectively suppressing sloshing caused by an earthquake or the like. A guide member is suspended below the roof, and a wave-dissipating member that can move up and down and slide while sliding along the guide member is provided.

  Embodiments of the liquid storage tank according to the present invention will be described below with reference to FIGS.

  FIG. 1A shows a cross-sectional view of a fixed roof tank 1A as an example of a liquid storage tank, and a wave-dissipating member 2 can be moved up and down via a guide member 3 inside the tank 1A. This is an example. FIG. 1B shows a plan view of the first example of the wave-dissipating member, and FIG. 1C shows a plan view of the second example of the wave-dissipating member.

  The fixed roof type tank 1A is, for example, a large cylindrical tank for storing crude oil 5, and includes a bottom plate 10 fixed on the ground, a cylindrical side wall 11, and a roof 12 fixed to the side wall 11. .

  A guide member 3 for connecting the roof 12 and the bottom plate 10 is disposed at a substantially central portion of the tank 1A, and the wave-dissipating member 2 is slidable up and down along the outer periphery of the guide member 3 to be movable. Attached.

  For example, as shown in FIG. 1B, the wave-dissipating member 2 includes a plurality of (for example, three sheets) rotating blades 20 and a boss portion 21 and a hole formed in the boss portion 21. A rotation assisting tool 21 </ b> A such as a bush or a bearing is attached to the portion 21 a and is configured to be slidable along the guide member 3.

  The guide member 3 may be a highly rigid rod or pipe, and is preferably made of a material that is not corroded or deteriorated by the stored liquid, such as stainless steel.

  Moreover, the material of the rotary blade 20 or the boss portion 21 may be any material that is neither corroded nor deteriorated by the stored liquid, and may be a hard resin product or a metal. However, when the tank 1A is shaken by an earthquake or the like and the liquid level is swung (referred to as sloshing), the rotating blade 20 is located near the liquid level in order to exert a wave-dissipating effect that suppresses the rocking. The buoyancy member 6 is preferably attached to the lower side of the wave-dissipating member 2.

  Further, if the buoyancy member 6 is attached to the lower part of the boss portion 21, it is preferable that the rotary blade 20 can be easily positioned near the liquid surface.

  If the buoyancy member has a ballast tank shape capable of pouring and draining, it is preferable that the buoyancy can be adjusted by injecting liquid so as to have an appropriate buoyancy. Further, when the liquid to be stored is limited to only crude oil, it may be made of a light material with a clear specific gravity, such as a polystyrene foam, instead of a ballast tank shape. However, when the type of liquid to be stored changes, a ballast tank-like one whose buoyancy can be adjusted by the specific gravity of the liquid to be stored is preferable.

  Further, if the buoyancy member can be adjusted in the form of a ballast tank, even when storing a liquid with an uncertain specific gravity, it can be poured and drained while visually checking the floating position of the rotary blade 20, so that the rotation It is easy and preferable to install the blade 20 at a predetermined position.

  In place of the rotary blade 20, it is possible to use the wave-absorbing member 2 </ b> A having a plurality of thin rotary blades 20 </ b> A as shown in FIG. 1C, and the specific gravity of the liquid to be stored, the size of the tank, etc. Can be changed.

  When so-called sloshing occurs that the liquid level fluctuates, the rotating blade 20 is rotated by the wave, so that the force of the wave that fluctuates is consumed by the rotational power, and the amplification of the fluctuation due to repeated fluctuations can be prevented. As a result, the effect of suppressing the oscillation is exhibited. That is, the wave-dissipating member 2 including the rotary blade 20 has a structure having a wave-dissipating effect.

  Further, when the degree of sloshing is large, the number of rotations of the rotary blade 20 is increased to increase the wave-dissipating effect. Therefore, the wave-dissipating member 2 having a predetermined size including the rotatable blade 20 is provided. It is possible to make the wave-dissipating member 2 effective for various liquid storage tanks 1A.

  The diameter D2 of the wave-dissipating member 2 may be about half of the inner diameter D1 of the fixed roof tank 1A as long as it is a rotary blade 20 having a large area similar to that of a fan. Oscillation can be sufficiently suppressed and a wave-dissipating effect can be exhibited.

  In the case of the rotor blade 20A having a relatively small area, a rotor blade having a slightly larger diameter is preferable.

  In order to suppress the sloshing, it is desirable that the rotary blade 20 and the rotary blade 20A be near the liquid surface. For this reason, the buoyancy member 6 is provided. Since it decreases, a lower limit can be set in the position of the rotary blade 20 or the rotary blade 20A. Therefore, in this embodiment, a stopper 4 is disposed at the lower end of the guide member 3 so that the wave-dissipating member 2 does not descend any further.

  Further, the height H1 of the fixed roof tank 1A is constant, but the stored liquid level height H2 is not constant, and varies depending on the amount of liquid to be taken out. The liquid level height H2 decreases and the upper space H3 increases.

  Even if the liquid surface height H2 fluctuates, the wave-dissipating member 2 including the rotary blades 20 is configured to automatically adjust to a position where buoyancy is balanced via the buoyancy member 6, and moves following the liquid surface fluctuation. Thus, the rotary blade 20 is always positioned near the liquid surface.

  Some liquid storage tanks have floating roofs with roofs that are not fixed to the side walls. Especially when storing crude oil and naphtha that are highly volatile and easily flammable, the roof moves up and down according to the amount of liquid that increases or decreases. A floating roof tank is used. An example of the floating roof tank is shown in FIG.

  2A shows a cross-sectional view of the floating roof tank 1B, and FIG. 2B shows an enlarged cross-sectional view of a sliding portion between the guide member 3A and the guide shaft body 30. FIG.

  The floating roof type tank 1B has a structure in which the roof moves up and down integrally with the liquid level as the amount of stored liquid increases and decreases, and a seal member 15 is attached to the outer peripheral side of the floating roof 13, The gap with the side wall 11 is sealed to prevent liquid leakage, and the floating roof 13 is slidable with respect to the side wall 11.

  Reference numeral 16 denotes a cover sheet, which is a rubber sheet with a reinforcing cloth that wraps the seal member 15 made of, for example, urethane rubber in a compressed state and is attached to the floating roof 13. Further, a flap-shaped weather shield 14 is attached to the outer periphery of the upper surface of the floating roof 13 so as to slidably support the floating roof 13, and rain water or the like is contained in the side wall 11. It is prevented from flowing along the wall.

  Since the floating roof 13 is configured as described above, it normally moves up and down in close contact with the liquid surface with the roof floating. For this reason, when sloshing occurs, the floating roof 13 swings together with the swinging liquid surface, so that the liquid surface is restrained from swinging and becomes a sliding portion between the tank body and the floating roof 13. It is important to prevent liquid leakage from the seal member 15.

  Therefore, in this embodiment, the guide member 3A is suspended and fixed to the lower side of the floating roof 13, and the wave-dissipating member 2 that can slide up and down along the guide member 3A is mounted. The wave-dissipating member 2 is the same as the wave-dissipating member 2 described in FIG. 1 and will not be described in detail here.

  The wave-dissipating member 2 is in a state of floating in the liquid, but it is the same to attach a buoyancy member 6 for adjusting the position of the wave-dissipating member 2, and further, a stopper 4 for regulating the lower limit position of the wave-dissipating member 2 is provided. The provision is the same. Further, a stopper 4 </ b> A for restricting the upper limit of the wave-dissipating member 2 may be provided at the lower part of the floating roof 13.

  The guide member 3A has a pipe shape and is configured to be fitted to a guide shaft body 30 fixed to the bottom plate 10 and projecting upward. Therefore, the floating roof 13 moves up and down with the movement of the stored liquid level, but the up and down movement is performed while being guided by the guide shaft body 30 and the guide member 3A. However, the floating roof 13 does not tilt and the liquid does not leak from the sealing member 15. Furthermore, since the wave-dissipating member 2 having rotating blades is mounted, it is possible to prevent amplification of fluctuation due to repeated liquid level fluctuation, and as a result, the effect of suppressing the fluctuation is exhibited.

  As shown in FIG. 2B, the guide shaft body 30 has a tip portion 30a that is thin and pointed, and has a shape in which the pipe-shaped guide member 3A can be easily fitted. Further, a rotation assisting tool 31 such as a bush or a bearing is mounted inside the guide member 3 </ b> A so that the guide member 3 </ b> A slides easily along the guide shaft body 30.

  As the wave-dissipating member 2, the wave-dissipating member 2 </ b> B including the disc 22 shown in FIG. 3 can be used in addition to the rotating blade 20 and the rotating blade 20 </ b> A. 3A shows a side sectional view, and FIG. 3B shows a plan view.

  The wave-dissipating member 2B has a shape in which a plurality of rotor blades 23 are disposed on a disc 22 having a boss portion 21. In addition to suppressing liquid surface oscillation (sloshing) due to rotation, the wave-dissipating member 2B is also affected by the resistance of the disc. Sloshing can be suppressed.

  Similarly, the boss portion 21 is provided with a hole portion 21a including a rotation auxiliary tool 21A, and the wave-dissipating member 2B is also slidable along the guide member 3 through the hole portion 21a. Has been. This is the same as the wave-dissipating member 2 including the rotary blade 20 and the rotary blade 20A described above, and will not be described in detail here.

  The rotary blade 23 may be simply a flat plate shape, a curved guide blade, or a spiral shape, and is not particularly limited.

  Moreover, as shown to Fig.4 (a), it can also be set as the wave-absorbing member 2C of the shape provided with the multistage rotary blade 20 and the rotary blade 20A, as shown in FIG.4 (b). The wave-dissipating member 2 </ b> D having the shape provided may be used, or the wave-dissipating member 2 </ b> E having a shape in which the rotating blades are spirally disposed as illustrated in FIG. 4C.

  As described above, when a multistage or spiral wave-dissipating member is used, the area in the depth direction where the wave is received is increased, and the wave-dissipating effect is increased. In addition, the wave breaking effect can be further increased by deflecting the traveling wave direction.

  When one wave-dissipating member described in FIG. 2 to FIG. 4 is disposed in the tank, the diameter of the wave-dissipating member may be about D2 shown in FIG. 1, and substantially half of the inner diameter D1 of the tank. Any degree is acceptable.

  Furthermore, as shown in FIG. 5, a plurality of small wave-dissipating members 2 </ b> F may be disposed in the liquid storage tank 1. FIG. 5A is a side sectional view of the liquid storage tank 1, and FIG. 5B is a plan sectional view.

  Each of the wave-dissipating members 2F is slidable along the respective guide members 3 like the other wave-dissipating members described so far, and a stopper 4 is provided below the guide member 3. Are arranged respectively. It is also the same that the buoyancy member 6 is disposed as necessary.

  However, the diameter D3 is small, and when the plurality of wave-dissipating members 2E are disposed in the tank having the internal diameter D1, the adjacent wave-dissipating members 2F do not come into contact with each other.

  Further, the number to be arranged is not limited to four shown in the figure, and may be three or five, and may be a quantity that does not contact the side wall 11 of the tank or the adjacent wave-dissipating member.

  With this configuration, by disposing a plurality of relatively small wave-dissipating members, each of the installation positions works to suppress the oscillation in accordance with the oscillation of the liquid level in the tank. Every part in the tank can be finely waved, and the amplification of shaking due to repeated shaking can be further prevented. As a result, it is possible to suppress the liquid surface from being shaken by vibration such as an earthquake, and to prevent the liquid from leaking from the tank or the tank from being damaged.

  What has been described above is about the wave-dissipating member that is rotated by sloshing, but recently, by detecting the seismic wave, it is detected that the earthquake arrives before the actual earthquake occurs. Can be done.

  For this purpose, as shown in FIG. 6A, the guide member 3B is passed through the roof 12A and supported rotatably via the rotation auxiliary tool 12Aa, and the protruding portion 3Ba protruding on the roof 12A is driven. The motor M is rotationally driven. The drive motor M installed on the roof 12A is connected to the projecting portion 3Ba via a connecting member T, and drives the drive motor M by a signal from a seismic wave detecting means installed separately to guide the guide member. The wave-dissipating member 2G attached to 3B may be rotated.

  If it is this structure, when the earthquake wave which arises in the case of an earthquake is detected beforehand and it judges that an earthquake will generate | occur | produce in a storage tank base, the said wave-dissipating member 2G can be rotated automatically. For this reason, it is possible to detect the occurrence of sloshing in the near future and drive the wave-dissipating member before the sloshing occurs to suppress the occurrence and growth of sloshing.

  The connecting member T for connecting and driving the drive motor M installed on the roof 12A and the guide member 3B suspended from the roof 12A may be a transmission member using a worm and a worm wheel. A transmission member using a bevel gear may be used as long as the guide member 3B is rotationally driven by the rotation of the drive motor M.

  When detecting the occurrence of an earthquake in advance and actively rotating the wave-dissipating member 2G, it is better to enable driving power to be generated within the premises of the storage tank base. In addition to supplying power, the seismic wave detection means 18 is disposed between the power transmission path between the power generation device 17 and the drive motor M, and when the seismic wave detection means 18 detects an earthquake wave, the drive motor M is supplied. The power transmission may be configured as follows.

  The wave-dissipating member 2G is slidable along the guide member 3B extending from the roof 12A to the bottom plate 10 like the other wave-dissipating members described so far, and a stopper 4 is provided below the guide member 3B. Are arranged respectively. It is also the same that the buoyancy member 6 is provided as necessary so that the rotary blade is always located near the liquid surface.

  FIG. 6B shows a plan view of the wave-dissipating member 2 </ b> G including the rotary blade 20. In order to rotate the wave-dissipating member 2G together with the positively rotatable guide member 3B, for example, a convex portion 3Bb along the axis is provided on the outer peripheral surface of the guide member 3B, and the concave portion 2Ga engaged with the convex portion is provided. What is necessary is just to provide in the said wave-dissipating member 2G. Further, the convex portion 3Bb may be provided with a plurality of lines on the outer peripheral surface of the guide member 3B. Moreover, the convex part parallel to the axis may not be a convex part but may be a helical convex part that gently slopes along the axial surface, and the wave-dissipating member 2G including the concave part 2Ga that engages with the convex part 3Bb is a guide member. What is necessary is just to set it as the structure which can slide along the axis line of 3B.

  With the configuration as described above, when the guide member 3B is driven and rotated by the drive motor M, the wave-dissipating member 2G also rotates together with the rotating blades, and an earthquake wave arrives and is generated. Sloshing can be suppressed in advance. Further, it is more preferable that the shape of the rotary blade is a blade shape that pushes the stored liquid downward when the wave-dissipating member 2G rotates.

  As described above, according to the present invention, it is possible to effectively suppress sloshing caused by an earthquake or the like and to include a wave-dissipating member that can be attached to a fixed roof tank or a floating roof tank. It can be a liquid storage tank.

An example of the liquid storage tank according to the present invention is shown, (a) is a cross-sectional view of a fixed roof type liquid storage tank 1A, (b) is a plan view of a first example of the wave-dissipating member, (C) shows a plan view of the wave-dissipating member of the second example. An example of a floating roof type tank is shown, (a) shows a sectional view of the entire tank, and (b) shows an enlarged sectional view of a sliding portion between the guide member 3A and the guide shaft body 30. . The 3rd example of the wave-dissipating member is shown, (a) shows side surface sectional drawing, (b) has shown the top view. The other example of the wave-dissipating member is shown, (a) is a side view of a multistage wave-dissipating member, (b) is a side view of the wave-dissipating member provided with a helical screw, (c ) Is a perspective view of a wave-dissipating member in which rotating blades are spirally arranged. 2 shows a liquid storage tank in which a plurality of small wave-dissipating members are arranged, (a) is a side sectional view of the entire tank, and (b) is a plan sectional view of the tank. An example of the liquid storage tank provided with the wave-absorbing member driven positively is shown, (a) is a side sectional view of the whole tank, and (b) is a plan view of the wave-absorbing member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid storage tank 1A Fixed roof type tank 1B Floating roof type tank 2 Wave-dissipating member 2Ga recessed part 3 Guide member 3Bb Convex part 4 Stopper 5 Crude oil 6 Buoyant member 10 Bottom plate 11 Side wall 12 Roof 13 Floating roof 20 Rotary blade 21 Boss body 30 Guide Shaft body D1 Tank inner diameter D2 Diameter of wave-dissipating member

Claims (9)

A liquid storage tank for storing crude oil, chemicals, etc.
A guide member is suspended below the tank roof, and a wave-dissipating member that is movable up and down while sliding along the guide member is disposed, and the wave-dissipating member is located near the liquid surface. A liquid storage tank comprising a buoyancy member as described above.   The liquid storage tank according to claim 1, wherein the wave-dissipating member includes a rotary blade.   The liquid storage tank according to claim 1, wherein the wave-dissipating member includes a rotary blade at a lower portion of a disk.   The guide member is arranged in the center of the roof, and the diameter of the wave-dissipating member is about half of the inner diameter of the tank, and the lower limit when the wave-dissipating member moves up and down below the guide member is regulated. The liquid storage tank according to claim 1, wherein a stopper is provided.   A plurality of the guide members are arranged on the roof so that the diameter of the wave-dissipating member is such that adjacent wave-dissipating members do not contact each other, and the wave-dissipating member moves up and down below each guide member. The liquid storage tank according to any one of claims 1 to 3, wherein a stopper is provided to limit a lower limit when the liquid storage is performed.   6. The buoyancy adjustment member in the form of a ballast tank in which the buoyancy member can be poured and drained, wherein the buoyancy is adjusted by injecting a liquid into the tank. Liquid storage tank.   The liquid storage tank according to any one of claims 1 to 6, wherein the liquid storage tank is a fixed roof tank, and the guide member connects a bottom plate of the tank and the roof.   The liquid storage tank is a floating roof type tank, wherein the guide member is a cylinder, and a guide shaft body that slides and guides the guide member is disposed upward from the tank bottom plate portion. Item 7. A liquid storage tank according to any one of Items 1 to 6. A liquid storage tank for storing crude oil, chemicals, etc.
A guide member that penetrates the roof of the tank and reaches the bottom plate is disposed, and a drive motor that rotationally drives the guide member is installed on the roof, and the projecting portion of the guide member that projects on the roof and the drive Connect the motor via the connecting member,
A wave-dissipating member having a concave portion that engages with a convex portion provided in the axial direction of a guide member that hangs under the roof is slidable in the axial direction of the guide member and rotates together with the guide member. Attached to the guide member as possible,
While comprising a buoyancy member so that the wave-dissipating member is located near the liquid surface,
A liquid storage tank characterized in that the drive motor is driven to rotate by a detection signal from a seismic wave detection means installed separately.

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