JP2008013224A - Sloshing damper and modification method of existing tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive sloshing damper placed under a floating roof, which prevents a damage caused by contacting with a floating roof for a long time. <P>SOLUTION: This sloshing damper includes a float structure F positioned under a floating roof covering a liquid body stored in a tank and a damping body D for attenuating the flow rate of a liquid being supported by the structure F. The float structure F includes a flat face frame structure 1 formed by combining a plurality of rod elements and a shock absorbing member 2 for preventing a damage caused by contacting with the floating roof. The shock absorbing member 2 is formed into a ring shape and circularly mounted on the rod elements. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sloshing damping device and a method for repairing an existing tank.

  When seismic forces act on oil tanks installed in refineries or storage tanks installed in chemical plants, sloshing may occur in the liquid (oil, crude oil, solution, etc.) stored in the tank. is there.

  As the scale of sloshing becomes large, there is a risk of incurring liquid leakage or tank destruction. For example, as disclosed in Patent Document 1, a sloshing attenuation device that attenuates sloshing is installed inside the tank. There is a case.

  The sloshing attenuation device of Patent Document 1 is configured to include a float structure disposed below the floating roof that covers the liquid surface, and an attenuation body that attenuates the flow rate of the liquid. The float structure is configured to include a plurality of rod-like elements combined in a plan view lattice shape or a radial shape. The attenuation body includes a net-like member made of a perforated plate or a wire net, and is supported by the float structure.

  By the way, since the vibration characteristics are different between the floating roof and the sloshing damping device, when the floating roof and the sloshing damping device are not connected, they swing separately, and the floating roof and the float structure are separated. Contact and separation are repeated, or the upper surface of the float structure floats and slides on the lower surface of the roof. If the floating roof and the float structure are in direct contact with each other, they will be damaged each other. Therefore, it is necessary to arrange a cushioning material for preventing damage on the upper surface of the float structure.

JP 2006-8148 A

  As means for fixing the cushioning material to the float structure, chemical bonding methods such as adhesion and mechanical bonding methods such as bolt bonding are conceivable. However, when chemical bonding methods are used, there is a problem in durability. However, in the case of the mechanical joining method, the number of parts increases, and a new measure for preventing damage due to the contact between the bolt and the floating roof is required, leading to an increase in manufacturing cost. become.

  This type of sloshing damping device can be applied to both new tanks and existing tanks. However, when applied to existing tanks, it is necessary to remove the floating roof once, so renovation work is significant. It becomes a thing of scale.

  From this point of view, the present invention is a sloshing damping device installed on the lower side of a floating roof, and can prevent damage due to contact with the floating roof over a long period of time while being inexpensive. It is a first problem to provide a sloshing damping device, and in addition, a second problem is to provide a method for repairing an existing tank capable of reducing the size of repair work.

  The sloshing damping device according to the present invention, which was created to solve the first problem described above, includes a float structure disposed below a floating roof that covers a liquid stored in a tank, and the float structure. An attenuator for attenuating the flow rate of the liquid, and the float structure prevents damage to the flat frame due to contact between the flat frame formed by combining a plurality of rod-shaped elements and the floating roof. A sloshing damping device comprising a cushioning material, wherein the cushioning material is formed in a ring shape or a C shape and is mounted on the rod-shaped element.

  In this way, the possibility that the cushioning material will fall off the rod-like element becomes extremely small, so that damage due to contact with the floating roof can be prevented over a long period of time. In particular, if the cushioning material has a complete ring shape, it will not fall off from the rod-shaped element unless it is torn off. Also, if the cushioning material is ring-shaped or C-shaped, it can be firmly fixed to the rod-shaped element without using adhesives or bolts, so the number of parts and assembly man-hours can be reduced. As a result, the manufacturing cost of the sloshing attenuation device can be reduced. In addition, since the plane frame can be disassembled into a plurality of bar-like elements, even if the carry-in route is narrow, it can be carried in easily.

  Although there is no restriction | limiting in particular in the support type of an attenuation body, The said attenuation body is good to suspend from the said rod-shaped element. If a space is formed between the liquid surface and the floating roof, the liquid is vaporized and fills the above-described space. Therefore, when the liquid is flammable, the floating roof is always liquid. However, when the damping body is suspended from the rod-shaped element, the bottom of the floating body and the sloshing damping device are lowered when the lower end of the damping body comes into contact with the bottom surface of the tank. If the movement is restricted and the liquid is further reduced, a space is formed between the liquid surface and the floating roof, so that the liquid stored in the bottom of the tank may not be utilized. In such a case, it is preferable that the height of the attenuation body is adjustable. In this way, the floating roof and the sloshing damping device can be lowered further downward, so that the liquid stored in the bottom of the tank can be used effectively.

  The float structure may be provided with a support member projecting downward from the rod-shaped element, and the attenuation member may be supported by the support member. In this way, the damping body can be firmly held, so that even if the flow resistance acting on the damping body is large, it is possible to reliably attenuate the flow rate of the fluid.

  In particular, when the support member is configured to include a pair of diagonal members arranged in a V-shape and forms a truss structure with the rod-shaped element, the damping body is more securely held. It becomes possible.

  There is no restriction | limiting in particular in the form of an oblique material, The bendable linear member other than a strip | belt board, a shape steel, etc. can be used as an oblique material. In particular, when the height dimension of the attenuation body is adjustable, it is desirable that the bendable linear member is an oblique material. In this way, the diagonal material does not get in the way when the damping body contracts.

  Further, the form of the plane frame is not particularly limited, but when at least a part of the plane frame includes a truss structure in which the rod-like elements are combined in a triangular shape in plan view, the plane frame is formed. Since the rigidity and strength of the steel frame will be improved, it is difficult for deformation and bending to occur in the plane frame.

  When the plurality of bar-shaped elements include a plurality of radial frames arranged along the direction from the center portion of the planar frame toward the outer edge, the attenuation body is disposed along the radial frame. It is good to arrange. In this way, sloshing can be attenuated even if the vibration direction changes.

  When the plane frame includes a radial frame, a central member is disposed at a central portion of the plane frame, and at least two of the plurality of radial frames are connected to each other via the central member. Good. If it does in this way, the rigidity and intensity in the center part of a plane frame will improve.

  The radial frame may be constituted by a hollow pipe whose both ends are closed. In other words, the radial frame may be configured using a hollow pipe in which a sealed hollow space is formed. In this way, it is possible to reduce the weight of the plane frame, and in addition, the radial frame itself functions as “floating”, so that members that give buoyancy to the sloshing damping device are omitted or reduced. It becomes possible. Note that if the hollow pipe is formed of an extruded shape made of an aluminum alloy, it is possible to further reduce the weight of the plane frame.

  When the plurality of rod-shaped elements include a plurality of circumferential frames arranged to form a polygonal shape in plan view, the radial frame and the circumferential frame may be joined. In this way, the circumferential interval between the radial frames can be kept constant, so that the circumferential rigidity and strength of the planar frame can be improved.

  The circumferential frame may be composed of a hollow pipe whose both ends are closed. That is, the circumferential frame may be configured using a hollow pipe in which a hollow space sealed inside is formed. In this way, it is possible to reduce the weight of the plane frame, and in addition, the circumferential frame itself functions as “floating”, so that members that give buoyancy to the sloshing damping device are omitted or reduced. It becomes possible. Note that if the hollow pipe is formed of an extruded shape made of an aluminum alloy, it is possible to further reduce the weight of the plane frame.

  When the plurality of peripheral frames include a plurality of outer peripheral frames that form the outline of the plane frame, the radial interval between the radial frames is kept constant at the outer edge of the plane frame. Therefore, the rigidity and strength at the outer edge of the plane frame are improved.

  Moreover, it is good to arrange | position a guide member on the outer side of the said plane frame. If it does in this way, it will become possible to prevent damage to the plane frame by contact to the inner peripheral surface of the tank. In addition, when a plurality of outer peripheral frames are arranged on the outer edge of the planar frame, a guide member may be arranged outside the joint portion between the outer peripheral frames.

  Although there is no restriction | limiting in particular in the form of the said guide member, It is desirable to have a sandwich panel which encloses the core material which consists of an aggregate of a honeycomb-shaped core material or a cylindrical body. If it does in this way, since a guide member will become lightweight, it will become possible to achieve weight reduction of a float structure.

  The existing tank renovation method according to the present invention, which was created to solve the above-mentioned second problem, is the construction of an existing tank by constructing a sloshing attenuation device for attenuating sloshing inside an existing tank having a floating roof. A method of repairing an existing tank to improve the earthquake resistance of the existing tank, wherein the liquid stored in the existing tank is discharged and the floating roof is lowered to secure a work space between the bottom surface of the tank and the floating roof A step of carrying in a plurality of rod-shaped elements and an attenuation body for attenuating the flow rate of the fluid from the inspection port provided in the existing tank into the work space; A flat frame that is substantially parallel to the bottom surface of the tank is constructed by combining rod-shaped elements, and the damping material is attached to the rod-shaped elements, so that a slot is formed below the floating roof. Characterized by comprising the steps of: constructing a ring damping device.

  By refurbishing existing tanks in this way, it is possible to build a sloshing damping device under the floating roof without removing the floating roof, so it is possible to reduce the size of the repair work. Become.

  According to the sloshing damping device according to the present invention, it is possible to prevent damage due to contact with the floating roof over a long period of time while being inexpensive.

  Further, according to the method for repairing an existing tank according to the present invention, it is possible to reduce the size of the repair work.

  The sloshing damping device according to the present embodiment is disposed below the floating roof R that covers the liquid L stored in the tank T as shown in FIG. And the damping body D, and moves up and down as the liquid L increases and decreases.

  The float structure F holds the attenuation body D. In this embodiment, the float structure F floats in the upper layer portion of the liquid L due to buoyancy from the liquid L. As shown in FIG. 1 (b), the float structure F includes a plane frame 1 formed by combining a plurality of bar-shaped elements, a cushioning material 2 (see FIG. 2) attached to the bar-shaped elements, and a lower side from the bar-shaped elements. The support member 3 (refer FIG. 2) extended toward the direction, and the guide member 4 arrange | positioned on the outer side of the plane frame 1 are comprised. The float structure F may be floating on the upper layer portion of the liquid L while being in contact with the lower surface of the floating roof R, or may be floating on the upper layer portion of the liquid L while being separated from the lower surface of the floating roof R. It can be anything.

  The plane frame 1 is a plane frame structure configured by combining a plurality of rod-like elements with the center member 11 as a center, and the frame surface is substantially parallel to the bottom surface of the tank T in normal times. (See (b) of FIG. 1). The plurality of rod-shaped elements include a plurality of radial frames 12, 12,... Disposed along a direction from the center of the plane frame 1 toward the outer edge (hereinafter referred to as “radial direction”), and the central member 11. A plurality of first circumferential frames 13, 13,... Arranged to form a polygonal shape in plan view on the outer peripheral side, and a plurality of second frames arranged to form a polygonal shape in plan view at the outer edge of the plane frame 1. , And circumferential frames 14, 14,... In the following description, the first circumferential frame 13 is referred to as “inner frame 13” and the second circumferential frame 14 is referred to as “outer frame 14”.

  That is, the plane frame 1 surrounds the central member 11, a plurality of radial frames 12, 12,... Arranged radially around the central member 11, and the radial frames 12, 12,. Are provided with a plurality of outer peripheral frames 14, 14,... And a plurality of inner peripheral frames 13, 13,... Arranged so as to surround the central member 11 on the inner peripheral side of the outer peripheral frames 14, 14,. It is configured.

  The central member 11 is a member disposed at the center of the plane frame 1 and connects a plurality of (eight in the present embodiment) radial frames 12, 12,. As shown in FIG. 2, the center member 11 has a polygonal shape in plan view, and the end of the radial frame 12 is joined to the center of each side. As shown to (a) of FIG. 3, the center member 11 is provided with the cyclic | annular part 11a which exhibits a planar view polygon, and several connection part 11b, 11b, ... which protrudes in the outer peripheral side of the cyclic | annular part 11a. Configured. The annular portion 11a has a cross-sectional groove shape that opens outward. The connection part 11b consists of a plate-shaped member which has a through-hole, and is fixed to the groove part of the annular part 11a by welding. In the present embodiment, the planar shape of the central member 11 is a regular polygon (regular octagon in the present embodiment) having the same number of sides as the number of radial frames 12 connected to the central member 11. However, it may be a polygon having a larger or smaller number of sides than the number of radial frames 12, or a circular shape.

  As shown in FIG. 3B, the center member 11 is composed of two ring constituting members 11A and 11A having a substantially C shape. That is, the center member 11 is configured to be splittable. By the way, for the connecting portion 11b located at the boundary between the two ring components 11A, 11A, the plate-like member provided at the end of one ring component 11A and the end of the other ring component 11A It is comprised with the provided plate-shaped member. In addition, although illustration is abbreviate | omitted, you may comprise the center member 11 so that division | segmentation into three or more ring components is possible.

  The radial frame 12 is disposed along a straight line passing through the center of the central member 11 as shown in FIG. In the present embodiment, the radial frames 12, 12 adjacent to each other in the radial direction are connected to each other via the center member 11 or the inner peripheral frame 13. The radial frame 12 includes a frame disposed between the central member 11 and the inner peripheral frame 13 and a frame disposed between the inner peripheral frame 13 and the outer peripheral frame 14. Since the same configuration is provided, the radial frame 12 disposed between the central member 11 and the inner peripheral frame 13 will be described below.

  The plurality of radial frames 12, 12,... Connected to the central member 11 are arranged at equal intervals in the circumferential direction. That is, the angles formed by the radial frames 12 and 12 adjacent in the circumferential direction are all the same.

  As shown in FIG. 4, the radial direction frame 12 includes a main body portion 12 a in which a hermetically sealed hollow space is formed, a joint portion 12 b protruding from an end surface of the main body portion 12 a, and a main body portion 12 a. And a first mounting portion 12c projecting from the peripheral surface.

  As shown in FIG. 5A, the main body portion 12 a is configured to include a hollow pipe 121 that has a cylindrical shape, and closing plates 122 and 122 that close both ends of the hollow pipe 121. That is, the radial frame 12 includes a hollow pipe 121 whose both ends are closed. The hollow pipe 121 is made of an extruded shape made of an aluminum alloy, and the closing plate 122 is fixed to the end of the hollow pipe 121 by welding all around.

  The joint part 12b is a part connected to other members (such as the central member 11 and the inner peripheral frame 13 shown in FIG. 4) adjacent in the longitudinal direction of the radial frame 12. The joint portion 12b is made of a plate-like member having a through hole, and is fixed to the closing plate 122 by welding. As shown in FIG. 4, in order to join the central member 11 and the radial frame 12, the connecting portion 11 b of the central member 11 and the joint portion 12 b of the radial frame 12 are overlapped and then provided on them. A bolt may be inserted into the through hole and fastened with a nut.

  The first attachment portion 12c is a portion to which the attenuation body D is connected, and in the present embodiment, the first attachment portion 12c protrudes from the lower surface of the main body portion 12a. The attachment portion 12c is made of a plate-like member having a through hole, and is fixed to the peripheral surface of the main body portion 12a by welding. Although there is no restriction | limiting in particular in the position and number of the 1st attaching parts 12c, in this embodiment, it arrange | positions one each at the both ends of the main-body part 12a.

  In the present embodiment, the radial frame 12 formed using the cylindrical hollow pipe 121 (see FIG. 5A) is illustrated, but the configuration of the radial frame 12 is not limited. Although not shown, the radial frame 12 may be formed using a polygonal hollow pipe, or the radial frame 12 may be formed using a solid columnar or polygonal column. In addition, the radial frame 12 may be formed using a shape having a cross-section H shape or a cross-section I shape.

  As shown in FIG. 1B, the inner peripheral frames 13, 13,... Are joined together to form an intermediate ring 1 a that exhibits a polygon in plan view. That is, the inner peripheral frames 13 and 13 adjacent to each other in the circumferential direction (that is, the inner peripheral frames 13 and 13 that are adjacent two sides of the polygon) are joined in an oblique state to form a corner portion of the polygon. . The intermediate ring 1a is formed so as to surround the radial frames 12, 12,. The planar shape of the intermediate ring 1 a is a regular polygon having the same number of sides as the number of radial frames 12 connected to the central member 11. That is, the planar shape of the intermediate ring 1 a is similar to the planar shape of the central member 11.

  As shown in FIG. 2, the inner peripheral frame 13 is arranged so as to intersect with the radial frames 12, 12 aligned in a straight line at right angles (cross shape). As shown in FIG. 4, the inner peripheral frame 13 includes a main body portion 13 a in which a sealed hollow space is formed, a joint portion 13 b protruding from an end surface of the main body portion 13 a, and a main body portion 13 a. The connecting portion 13c is provided to protrude from the peripheral surface, and the second mounting portion 13d is provided to protrude from the peripheral surface of the main body portion 13a.

  As shown in FIG. 5B, the main body portion 13 a is configured to include a hollow pipe 131 having a cylindrical shape and blocking plates 132 and 132 that close both ends of the hollow pipe 131. That is, the inner peripheral frame 13 includes a hollow pipe 131 whose both ends are closed. The hollow pipe 131 is made of an extruded shape made of an aluminum alloy, and the closing plate 132 is fixed to the end of the hollow pipe 131 by all-around welding.

  The joint part 13b is a part connected to another adjacent inner peripheral frame 13. The joint portion 13b is made of a plate-like member having a through hole, and is fixed to the closing plate 132 by welding. The joint portion 13b is bent so that it can be joined to the other adjacent inner peripheral frame 13 in an oblique manner. In addition, in order to join the inner peripheral frames 13 and 13 adjacent to each other in the circumferential direction, as shown in FIG. 4, one joint portion 13 b and the other joint portion 13 b are overlapped and provided on these. A bolt may be inserted into the through hole and fastened with a nut.

  The connecting portion 13c is a portion to which the radial frame 12 is connected, and in the present embodiment, the connecting portion 13c protrudes from the side surface of the central portion of the main body portion 13a. In this embodiment, the connecting portion 13c is made of a plate-like member having a through hole, and is fixed to the peripheral surface of the main body portion 13a by welding. Although there exist what protrudes toward the center member 11 in the connection part 13c, and what protrudes toward the other side, the two connection parts 13c and 13c are arrange | positioned on the straight line. In order to join the radial frame 12 and the inner peripheral frame 13, the joint portion 12 b of the radial frame 12 and the connecting portion 13 c of the inner peripheral frame 13 are overlapped, and the through holes provided in these are overlapped. A bolt may be inserted through and tightened with a nut.

  The second attachment portion 13d is a portion to which the support member 3 is connected, and in the present embodiment, the second attachment portion 13d protrudes from the lower surface of the main body portion 13a. In the present embodiment, the second attachment portion 13d is made of a plate-like member having a through hole, and is fixed to the peripheral surface of the main body portion 13a by welding. In addition, a pair of 2nd attachment parts 13d and 13d are arrange | positioned in the vertical plane containing the center axis line of the main-body part 13a. Moreover, each 2nd attachment part 13d is located between the connection parts 13c and 13c and the coupling part 13b.

  In the present embodiment, the inner peripheral frame 13 formed using the cylindrical hollow pipe 131 (see FIG. 5B) is exemplified, but the form of the inner peripheral frame 13 is not limited. Although not shown, the inner peripheral frame 13 may be formed using a polygonal cylindrical hollow pipe, or the inner peripheral frame 13 may be formed using a solid columnar or polygonal column shape. In addition, the inner peripheral frame 13 may be formed using a shape having an H-shaped section or an I-shaped section.

  As shown in FIG. 1 (b), the outer peripheral frames 14, 14,... Form the outline of the planar frame 1, and form an outer peripheral ring 1b joined to each other to form a polygon in plan view. Yes. That is, the outer peripheral frames 14 and 14 adjacent to each other in the circumferential direction (that is, the inner peripheral frames 14 and 14 forming two adjacent sides of the polygon) are joined obliquely to form a polygon corner. The outer peripheral ring 1b is arranged so as to surround the radial frames 12, 12,... Connected to the outer peripheral side of the intermediate ring 1a. The planar shape of the outer peripheral ring 1b is a regular polygon having sides that are twice the number of radial frames 12 connected to the outer peripheral side of the intermediate ring 1a.

  There are a peripheral frame 14 to which the radial frame 12 is connected and a peripheral frame 14 to which the radial frame 12 is not connected. The outer peripheral frame 14 to which the radial frame 12 is connected is arranged so as to intersect with the radial frame 12 at a right angle (intersect in a T shape). Since the two types of outer peripheral frames 14 have the same configuration, the outer peripheral frame 14 to which the radial frame 12 is connected will be described below.

  As shown in FIG. 2, the outer peripheral frame 14 includes a main body part 14a in which a sealed hollow space is formed, a joint part 14b protruding from an end surface of the main body part 14a, and a peripheral part of the main body part 14a. A connecting portion 14c projecting from the surface, a second mounting portion 14d projecting from the peripheral surface of the main body portion 14a, and a third mounting portion 14e projecting from the peripheral surface of the main body portion 14a. Configured. In addition, since the structure of the main-body part 14a, the joint part 14b, and the 2nd attachment part 14c is the structure similar to the main-body part 13a, the joint part 13b, and the 2nd attachment part 13c of the above-mentioned inner periphery frame 13, respectively, the detail The detailed explanation is omitted.

  As shown in FIG. 6, the third attachment portion 14 e is a portion to which the guide member 4 is connected. In the present embodiment, the third attachment portion 14 e protrudes from the outer peripheral side surface of the main body portion 14 a. The third mounting portion 14e includes a mounting seat 141, a bolt 142, and a retaining member 143. The mounting seat 141 has a box shape and is fixed to the peripheral surface of the main body portion 14a by welding. The head of the bolt 142 is inside the mounting seat 141, and the shaft portion protrudes from a long hole (not shown) provided on the front end surface of the mounting seat 141. The retaining member 143 is fixed inside the mounting seat 141 and abuts against the head of the bolt 142 to prevent the bolt 142 from falling off.

  In the present embodiment, the outer peripheral frame 14 formed using a cylindrical hollow pipe is illustrated, but the form of the outer peripheral frame 14 is not limited. Although illustration is omitted, the outer peripheral frame 14 may be formed using a polygonal cylindrical hollow pipe, or the outer peripheral frame 14 may be formed using a solid columnar or polygonal column shape. In addition, the outer peripheral frame 14 may be formed by using a shape having an H-shaped section or an I-shaped section.

  In addition, when all of the radial direction frame 12, the inner peripheral frame 13, and the outer peripheral frame 14 are formed of solid shapes, a separate float (floating) for obtaining the buoyancy of the float structure is provided. There is a need to. Further, when a part of the plurality of rod-like elements (radial direction frame 12, inner peripheral frame 13 and outer peripheral frame 14) is hollow and the rest is solid, it is necessary to float the entire float structure. The number of hollow rod-shaped elements (that is, the rod-shaped elements having a sealed hollow space) and the volume of each hollow space must be set so that the buoyancy can be obtained. It is necessary to arrange the hollow rod-shaped elements in a balanced manner so that they float on the liquid surface in a balanced manner (that is, part or all of the float structure does not sink into the liquid). For example, if all the radial frames 12 are hollow, or the inner peripheral frame 13 and the outer peripheral frame 14 are hollow, the balance is good.

  The cushioning material 2 shown in FIG. 2 prevents damage to the flat frame 1 due to contact with the floating roof R (see FIG. 1 (a)), and includes a radial frame 12 and an inner peripheral frame that are rod-like elements. 13 and the outer peripheral frame 14. That is, the buffer material 2 prevents the metallic frame materials 12, 13, 14 and the metallic floating roof R from directly colliding with each other when the liquid level is shaken by an earthquake. It is installed for the purpose of preventing damage due to collision. As shown in FIGS. 5A and 5B, the cushioning material 2 is formed in a ring shape having an inner diameter substantially equal to the outer diameter of the rod-shaped element described above, and is externally fitted to the rod-shaped element described above. . In other words, in the present embodiment, the inner peripheral shape of the cushioning material 2 is substantially equal to the outer peripheral shape of the rod-shaped element so that it can be fitted onto the rod-shaped element.

  Although there is no restriction | limiting in particular in the position, the number, etc. of the shock absorbing material 2, In this embodiment, the four shock absorbing materials 2 are cyclically mounted per rod-shaped element. The four buffer materials 2, 2,... Are arranged at equal intervals (see FIG. 4). The material of the cushioning material 2 is softer than the material constituting the rod-shaped element (aluminum alloy in the present embodiment) and the floating roof R (see FIG. 1A), and depends on the stored liquid. For example, when the liquid is petroleum or heavy oil, rubber or synthetic resin having excellent oil resistance may be used as long as it does not corrode or deteriorate. Examples of the oil resistant rubber include nitrile rubber, fluorine rubber, acrylic rubber, and chloroprene rubber. For example, when the liquid is a chemical solution, rubber or synthetic resin excellent in chemical resistance may be used.

  In the present embodiment, the buffer material 2 whose inner peripheral shape is circular is illustrated corresponding to the rod-shaped element whose outer peripheral shape is circular, but the form of the buffer material 2 is not intended to be limited. For example, although illustration is omitted, when the outer peripheral shape of the rod-shaped element is a polygon, the inner peripheral shape of the cushioning material may be a polygon. Moreover, what is necessary is just to make the inner peripheral shape of a shock absorbing material into a shape suitable for a rod-shaped element, when a rod-shaped element is shapes other than circular and a polygon. Moreover, in this embodiment, although the buffer material 2 which exhibits a ring shape was illustrated, it is not limited to this, Although illustration is abbreviate | omitted, it may be a buffer material which exhibits a C-shape. Even in this case, when the outer peripheral shape of the rod-shaped element is not circular, the shape may be adjusted to that.

  The support member 3 shown in FIG. 2 supports the lower end portion of the attenuation body D, and is attached to the inner peripheral frame 13 and the outer peripheral frame 14 which are rod-shaped elements in this embodiment. The support member 3 includes a pair of diagonal members 31, 31 arranged in a V-shape and a connecting member 32 that connects the end portions of the diagonal members 31, 31. Forming a structure. The support member 3 attached to the inner peripheral frame 13 supports two attenuation bodies D adjacent in the radial direction, and the support member 3 attached to the outer peripheral frame 14 is between the inner peripheral frame 13 and the outer peripheral frame 14. However, since the basic structure is not different, the support member 3 attached to the inner peripheral frame 13 will be described in detail below.

  As shown in FIG. 7, the diagonal member 31 is arranged along a vertical plane including the inner peripheral frame 13 to be connected, and projects obliquely downward from the inner peripheral frame 13. The diagonal member 31 is made of a L-shaped section having through holes at both ends, and has an upper end connected to the inner peripheral frame 13 and a lower end connected to the connecting member 32. In order to join the inner peripheral frame 13 and the diagonal member 31, the second mounting portion 13 d of the inner peripheral frame 13 and the upper end portion of the diagonal member 31 are overlapped, and then the through holes provided in these are attached. Insert bolts and fasten with nuts.

  The connecting member 32 is disposed immediately below the joint portion between the radial frame 12 and the inner peripheral frame 13, and is located at the same height as the lower end portion of the attenuation body D in the present embodiment. The connecting member 32 includes a pair of first connection portions 32a and 32a to which the lower end portion of the diagonal member 31 is connected, and a pair of second connection portions 32b projecting from the first connection portion 32a toward the attenuation bodies D and D. , 32b. The second connection portions 32b and 32b are made of a material having an L-shaped cross section and are connected to the attenuation body D, respectively. That is, the attenuation bodies D and D adjacent to each other in the radial direction are connected by the second connection portion 32b. The 1st connection part 32a consists of a plate-shaped member fixed to the profile used as the 2nd connection part 32b by welding. In order to join the diagonal member 31 and the connecting member 32, the lower end portion of the diagonal member 31 and the first connecting portion 32 a of the connecting member 32 are overlapped, and bolts are inserted into the through holes provided in these members. Insert it and tighten it with a nut.

  In addition, although the case where the lower end part of the attenuation body D was supported by the support member 3 was illustrated in this embodiment, it is not limited to this, Although illustration is abbreviate | omitted, it is the middle of the height direction of the attenuation body D It does not matter even if it supports the part.

  The guide member 4 shown in FIG. 1B prevents damage to the flat frame 1 and damage to the inner peripheral surface of the tank T due to contact with the inner peripheral surface of the tank T. It is installed so as to face. The guide member 4 is arrange | positioned at the corner | angular part (joint part of the outer periphery frames 14 and 14 adjacent to the circumferential direction in this embodiment) of the outer periphery ring 1b which exhibits a planar view polygon. Referring to FIG. 6, the guide member 4 includes a sandwich panel 41 and brackets 42 and 42 attached to the left and right of the sandwich panel 41, and is adjacent to the circumferential direction. The outer peripheral frames 14 and 14 are installed on one third mounting portion 14e and the other third mounting portion 14e.

  The sandwich panel 41 includes a core material 41a made of an aggregate of honeycomb-shaped core materials or cylindrical bodies, a panel frame 41b disposed so as to surround the aggregate, and a pair disposed so as to sandwich them. The face plates 41c and 41c are provided. The core material 41a and the face plates 41c and 41c are brazed or bonded.

  The bracket 42 is made of a material having an L-shaped cross section, and is fixed to the panel frame 41b by welding.

  In order to attach the guide member 4 to the plane frame 1, the bolt 142 of the third attachment portion 14 e of the outer peripheral frame 14 may be inserted into the through hole provided in the bracket 42 and fastened with a nut.

  The attenuation body D shown in FIG. 2 attenuates the flow velocity of the liquid L (see FIG. 1A). In this embodiment, the attenuation body D is along a vertical plane including the radial frame 12 that is a rod-shaped element. Has been placed. The attenuation body D is suspended from the radial frame 12 and at least one side portion is supported by the support member 3.

  Note that it is not necessary to suspend the attenuating bodies D on all of the plurality of radial frames 12, and the attenuating bodies D may be suspended on some of the radial frames 12. Moreover, although the case where the attenuation body D is suspended from the radial direction frame 12 is illustrated in the present embodiment, the attachment position of the attenuation body D is not intended to be limited. Although illustration is omitted, the attenuation body D may be suspended from the inner peripheral frame 13 or the outer peripheral frame 14 instead of or in addition to the radial frame 12.

  The attenuation bodies D, D adjacent to each other in the radial direction are connected by a connecting member 32 of the support member 3. In addition, although illustration is abbreviate | omitted, you may connect the lower end parts of the attenuation bodies D and D adjacent to the circumferential direction, or the intermediate parts of a height direction with a shape material, a wire, etc.

  As shown in FIG. 4, the attenuation body D includes a plurality (two in this embodiment) of net units 5, 5 connected in the vertical direction, and suspension members 6, 6 that connect the net units 5, 5. And is configured.

  As shown in FIG. 8, the net unit 5 includes a net-like member 51 that has a rectangular shape in front view, a rectangular frame 52 that holds the net-like member 51, and a fixing plate 53 that presses the net-like member 51 against the frame 52. It is prepared for.

  The mesh member 51 is a planar member having a large number of holes (openings) such as a wire mesh or a perforated plate, and is fixed to the frame 52 by rivets.

  The frame 52 is disposed along the outer peripheral edge of the mesh member 51, and includes vertical frame members 52a and 52a and horizontal frame members 52b and 52b. The vertical frame member 52a and the horizontal frame member 52b are each formed of a square pipe and are joined to each other by welding.

  The fixing plate 53 is made of a plate-like member having a substantially triangular shape. In this embodiment, the fixing plate 53 is disposed at each of the four corners of the mesh member 51 and is fixed to the frame 52 by bolts and nuts.

  The suspension member 6 connects the net units 5 and 5 adjacent in the vertical direction, and is arranged along the side end surfaces of the net units 5 and 5 in this embodiment. In the present embodiment, the suspension member 6 is made of a L-shaped section, and is fixed to the vertical frame 52a of the frame 52 by bolts and nuts. As shown in FIG. 4, the upper end portion of the suspension member 6 extends to the upper end portion of the uppermost net unit 5 and is connected to the radial frame 12. In order to join the radial frame 12 and the suspension member 6, the first mounting portion 12 c of the radial frame 12 and the upper end portion of the suspension member 6 are overlapped, and then bolts are inserted into the through holes provided in these. Insert it and tighten it with a nut. Further, the lower end portion of the suspension member 6 extends to the lower end portion of the lowermost net unit 5 and is connected to the support member 3. In order to join the support member 3 and the suspension member 6, the second connection portion 32 b of the support member 3 and the lower end portion of the suspension member 6 are overlapped, and a bolt is inserted into a through hole provided in these. The nut may be fastened.

  Next, with reference to FIG. 9, a method for constructing the sloshing attenuation device will be described while explaining a method for repairing the existing tank T using the sloshing attenuation device. In the following description, the case where the sloshing attenuation device is built inside the existing tank T is exemplified, but this is not intended to exclude application to a new tank.

  The renovation method according to the present embodiment is to improve the earthquake resistance of the tank T by constructing a sloshing damping device inside the existing tank T provided with the floating roof R. A carrying-in process and an assembly process are included.

  In the floating roof descending step, as shown in FIG. 9A, the liquid stored in the tank T is discharged to lower the floating roof R, and the work space K is placed between the floating roof R and the bottom surface of the tank T. This is a process of securing

  As shown in FIG. 9B, the material carrying-in step is a step of carrying in a small portion the members constituting the sloshing damping device from the inspection port (not shown) provided in the tank T into the work space K. . That is, the material carrying-in step is a step of carrying in the plurality of rod-shaped elements (radial direction frame 12, inner peripheral frame 13, outer peripheral frame 14), support member 3, attenuation body D, and the like shown in FIG. In addition, it is good to wrap the buffer material 2 in a rod-shaped element beforehand in a factory or the like.

  In the assembly process, a plurality of bar-shaped elements are combined inside the work space K to construct a plane frame 1 substantially parallel to the bottom surface of the tank T, and an attenuation body D is attached to the bar-shaped elements. It is a process of constructing a sloshing attenuation device on the side.

  If the existing tank is refurbished in this way, the sloshing damping device can be constructed on the lower side of the floating roof R without removing the floating roof R. It becomes possible.

  Here, the above-described assembly process (that is, the method of constructing the sloshing attenuation device) will be described in detail.

  When a plurality of rod-shaped elements (radial direction frame 12, inner peripheral frame 13, outer peripheral frame 14) are carried into work space K, they are joined to each other by bolts and nuts, and a plane frame as shown in FIG. Assemble 1 When joining the rod-shaped elements, as shown in FIG. 2, the first mounting portion 12c and the second mounting portions 13d and 14d need to be placed downward. Is used as a temporary support, and the rod-shaped element is preferably suspended in the air (see FIG. 9C). In addition, when there is support | pillar R1 in the center part of the floating roof R, as shown to (a) of FIG. 10, it carries in in the state which divided | segmented the center member 11 into ring component material 11A, 11A, and after that, FIG. As shown in (b), the struts R1 may be joined to each other while being surrounded by the ring constituent members 11A and 11A. In this way, the ring-shaped central member 11 can be mounted on the column R1 without lifting the column R1, so that the repair work can be made small.

  Thereafter, when the guide member 4 is attached to the plane frame 1 (see FIG. 1B) and the net unit 5 is attached to the suspension member 6 (see FIG. 2), the construction of the sloshing attenuation device is completed.

  According to the sloshing damping device according to the present embodiment described above, as shown in FIG. 2 and the like, since the buffer material 2 is ring-shaped and is mounted on the rod-shaped element, the buffer material 2 can be dropped from the rod-shaped element. Therefore, it is possible to prevent the flat frame 1 from being damaged due to contact with the floating roof R over a long period of time. In particular, since the shock-absorbing material 2 has a complete ring shape, it does not fall off from the rod-shaped element unless it is torn off. In addition, it is possible to firmly fix the cushioning material 2 to the rod-like element without using an adhesive or bolts, so that it is possible to reduce the number of parts and the number of assembling steps, which in turn reduces sloshing. The production cost of the apparatus can be reduced.

In addition, the sloshing attenuation device according to the present embodiment has the following useful effects.
Since the plane frame 1 can be disassembled into a plurality of bar-like elements, even if the carry-in route is narrow, it can be carried in easily.

  Since the plurality of radial frames 12, 12,... Are connected through the central member 11, the rigidity and strength at the center of the planar frame 1 are improved, so that the planar frame 1 generated by the flow resistance of the liquid L is improved. It becomes possible to prevent deformation and distortion.

  The plurality of radial frames 12, 12,... Are connected by the inner ring 1a composed of a plurality of inner frames 13, 13,... And the outer ring 1b composed of a plurality of outer frames 14, 14,. Even if a large hydraulic pressure acts on D, the circumferential interval between the radial frames 12, 12,... Can be kept constant.

  Since the radial frame 12, the inner peripheral frame 13 and the outer peripheral frame 14 are made of aluminum alloy hollow pipes closed at both ends, the planar frame 1 becomes lighter. In addition, the radial frame 12, the inner peripheral frame 13 Since the outer frame 14 functions as “floating”, it is possible to omit or reduce a member that gives buoyancy to the sloshing damping device.

  Since the float structure F is provided with the support member 3, it is possible to hold the damping body D firmly. As a result, even when the flow resistance acting on the damping body D is large, the flow rate of the fluid can be reduced. It is possible to reliably attenuate. In particular, in the present embodiment, the support member 3 includes a pair of diagonal members 31 and 31 arranged in a V shape, and forms a truss structure together with the rod-shaped element (inner peripheral frame 13). Therefore, the attenuation body D can be held more firmly.

  Since the damping body D is arranged in each of the plurality of radial frames 12, 12,... Arranged along the radial direction, sloshing can be attenuated even if the vibration direction changes.

  As shown in FIG. 1B, since the guide member 4 is disposed outside the flat frame 1, it is possible to prevent damage to the flat frame 1 due to contact with the inner peripheral surface of the tank T. In addition, since the sandwich panel 41 containing the aggregate of the core material 41a made of the aggregate of the honeycomb-shaped core material or the cylindrical body is used, an increase in the weight of the float structure F can be minimized. It becomes.

Note that the configuration of the sloshing attenuation device described above may be changed as appropriate.
For example, in the plane frame 1 shown in FIG. 1B, the corner of the inner ring 1a (that is, the joint of the inner frames 13, 13) and the corner of the outer ring 1b (that is, the outer frame 14, 14) is positioned between the radial frames 12 and 12 adjacent to each other in the circumferential direction. However, like the plane frame 101 shown in FIG. You may make the position of the corner | angular part of the outer periphery ring 101b correspond with the radial direction flame | frame 12. FIG. In this way, a truss structure is formed on the plane frame 101 by combining rod-like elements in a triangular shape in plan view, so that compared to the plane frame 1 without the truss structure (see FIG. 1B). Thus, the rigidity and strength are improved, and the flat frame 101 is hardly deformed or bent.

  11A also includes a central member 11, a plurality of radial frames 12, 12,... Arranged radially around the central member 11, and the radial frames 12, , And a plurality of inner peripheral frames 13 disposed so as to surround the central member 11 on the inner peripheral side of the outer peripheral frames 14, 14,. , 13,..., But one radial frame 12 extending between the central member 11 and the outer peripheral frame 14 is disposed, and the inner peripheral frame 13 adjacent in the circumferential direction. The point that 13 is connected via the radial direction frame 12 is different from the plane frame 1 (refer to FIG. 1B).

  Further, in the plane frame 1 shown in FIG. 1B, the number of radial frames 12 connected to the central member 11 is the same as the number of sides of the central member 11, but this is not limitative. Instead, for example, the number of the radial frames 12 connected to the central member 11 may be larger than the number of sides of the central member 11 as in the planar frame 201 shown in FIG. In FIG. 11B, in the plane frame 201, the number of radial frames 12 connected to the central member 11 is twice the number of sides of the central member 11. In the plane frame 201, the radial frame 12 is connected to the central part and the corner part of the side of the central member 11 exhibiting a polygon in plan view.

  Further, in the plane frame 1 shown in FIG. 1A and the plane frame 101 shown in FIG. 11A, one side of the inner rings 1a and 101a is constituted by one inner frame 13, In the planar frame 201 shown in FIG. 11B, one side of the inner ring 201a is constituted by a plurality (two in the drawing) of the inner frame 13.

  Further, in the plane frame 1 shown in FIG. 1A, the case where there is one inner ring 1a is illustrated, but the present invention is not limited to this, and although not shown, the inner ring 1a is omitted. May be omitted, or two or more inner peripheral rings 301a may be arranged as in the plane frame 301 shown in FIG.

  In addition, when a space is formed between the liquid surface and the floating roof R, the liquid L is vaporized and fills the above-described space. Therefore, when the liquid L is flammable, the floating roof is used. Although it is necessary to keep R in close contact with the liquid surface at all times, when the damping body D is suspended from the rod-shaped element, the floating roof R and the lower end of the damping body D are in contact with the bottom surface of the tank T. Since the downward movement of the sloshing damping device is restricted and the liquid L is further reduced, a space is formed between the liquid surface and the floating roof R, so that the liquid L stored at the bottom of the tank T is retained. There are cases where it cannot be used. In such a case, as shown in FIG. 13, if the height dimension can be adjusted, the sloshing attenuation device can be lowered further downward, so that it is stored at the bottom of the tank T. It is possible to effectively use the liquid that has been produced.

  As shown in FIG. 13A, the attenuation body D ′ is configured to include an upper mesh unit 105 and a lower mesh unit 205, and is suspended from the radial frame 12 that is a rod-shaped element. .

  As shown in FIG. 14A, the upper mesh unit 105 includes a mesh member 51 (see FIG. 8) that has a rectangular shape in front view, a pair of guide frame members 54 and 54 that hold the mesh member 51, and a mesh shape. And a fixing plate 55 that presses the member 51 against the guide frame member 54.

  The guide frame member 54 has a guide groove 54a having an opening on the surface facing the other guide frame member 54. In the present embodiment, the guide frame member 54 is configured using a cross-sectional lip groove shape. In addition, as shown to (a) of FIG. 13, the connection part 54b connected to the radial direction frame 12 is protrudingly provided in the upper end surface of the guide frame material 54. As shown in FIG.

  As shown in FIG. 14A, the fixing plate 55 is disposed along the front surface of the guide frame member 54, and is fixed to the guide frame member 54 with rivets or the like.

  As shown in FIG. 14B, the lower mesh unit 205 includes a mesh member 51 having a rectangular shape in front view, a pair of left and right slide frame members 56 and 56 that hold the mesh member 51, and the slide frame member. The lower frame material 57 which connects the lower end parts of 56 and 56 is comprised.

  The slide frame material 56 includes a slide portion 56a that can slide in the vertical direction (the vertical direction in FIG. 14B) in the guide groove 54a of the guide frame material 54, and the other slide frame material of the slide portion 56a. 56 is provided with a pair of clamping portions 56b, 56b projecting from the surface facing 56. The sandwiching portion 56b sandwiches the mesh member 51. In the present embodiment, the sandwiching portion 56b is made of a material having an L-shaped cross section, and is fixed to the slide portion 56a with a rivet or the like.

  As shown in FIGS. 13A and 13B, the lower end portion of the attenuation body D ′ is also supported by a support member 103 including a pair of diagonal members 33 and 33 arranged in a V shape. However, the diagonal member 33 is composed of a bendable linear member. In addition, the bendable linear member includes, for example, a single wire made of steel, carbon fiber, synthetic resin, a stranded wire, a rope, a chain, or the like.

  Then, when the sloshing damping device is lowered and the lower end of the damping body D ′ (that is, the lower end surface of the lower mesh unit 205) comes into contact with the bottom surface of the tank T, the guide groove 54a (see FIG. a)), the slide portion 56a (see FIG. 14B) of the lower mesh unit 205 enters, and finally, as shown in FIG. Since the side net unit 205 is accommodated, the plane frame 1 can be brought close to the bottom surface of the tank T, and as a result, the liquid stored in the bottom of the tank T can be used effectively. In addition, since the diagonal member 33 is comprised by the linear member which can be bent, entry into the upper net unit 105 of the lower net unit 205 is not inhibited.

  When the sloshing damping device rises as the liquid level rises, the lower net unit 205 comes out of the upper net unit 105 due to its own weight, and is automatically restored to the state of FIG.

  In the present embodiment, a plurality of mesh units (in this embodiment, the upper mesh unit 105 and the lower mesh unit 205) are slidably arranged in the vertical direction so as to be able to adjust the height dimension. However, it is not intended to limit the form of the attenuation body whose height can be adjusted. Although illustration is omitted, for example, an attenuation body capable of adjusting the height dimension can be formed also by connecting a plurality of net units in a foldable manner.

(A) is sectional drawing which shows the sloshing attenuation apparatus which concerns on embodiment of this invention, (b) is a top view. It is an expansion perspective view of the sloshing damping device concerning the embodiment of the present invention. (A) is an expansion perspective view which shows the center part of a plane frame, (b) is a disassembled perspective view of a center member. It is an expansion disassembled perspective view of the sloshing damping device concerning the embodiment of the present invention. (A) is an exploded perspective view of a radial direction frame, (b) is an exploded perspective view of a circumferential direction frame. It is an expanded sectional view which shows the outer edge part of a plane frame. It is an expansion perspective view which shows a supporting member. It is a disassembled perspective view which shows an attenuation body. (A)-(c) is a schematic diagram for demonstrating the repair method of the existing tank which concerns on embodiment of this invention. (A) And (b) is a top view for demonstrating the assembly method of a center member. (A) And (b) is a top view which shows the modification of a plane frame. It is a top view which shows the other modification of a plane frame. (A) is sectional drawing which shows the modification of an attenuation body and a supporting member, (b) is sectional drawing which shows the attenuation body of the folded state. (A) is the sectional view on the AA line of (a) of FIG. 13, (b) is the sectional view on the II line of (a) of FIG.

Explanation of symbols

F Float structure D Attenuator 1 Plane frame 11 Central member 12 Radial frame 12a Hollow pipe 13 Inner frame (circumferential frame)
13a Hollow pipe 14 Outer frame (circumferential frame)
14a Hollow pipe 2 Buffer material 3 Support member 31, 33 Diagonal material 4 Guide member 41 Sandwich panel 41a Cylindrical core T Tank R Floating roof

Claims (19)

A float structure disposed below the floating roof covering the liquid stored in the tank;
An attenuator that is supported by the float structure and attenuates the flow rate of the liquid,
The float structure is a sloshing attenuation device comprising a plane frame formed by combining a plurality of rod-shaped elements and a cushioning material that prevents damage to the plane frame due to contact with the floating roof,
A sloshing damping device, wherein the cushioning material is formed in a ring shape or a C shape and is mounted on the rod-shaped element.   The sloshing damping device according to claim 1, wherein the damping body is suspended from the rod-shaped element.   The sloshing attenuation device according to any one of claims 1 and 2, wherein the attenuation body has a structure capable of adjusting a height dimension thereof. The float structure includes a support member projecting downward from the rod-shaped element,
The sloshing attenuation device according to any one of claims 1 to 3, wherein the attenuation body is supported by the support member.   The sloshing damping device according to claim 4, wherein the support member is configured to include a pair of diagonal members arranged in a V shape, and forms a truss structure together with the rod-shaped element.   6. The sloshing damping device according to claim 5, wherein the diagonal member is constituted by a bendable linear member.   The sloshing attenuation according to any one of claims 1 to 6, wherein a truss structure formed by combining the rod-like elements in a triangular shape in plan view is included in at least a part of the planar frame. apparatus. The plurality of rod-shaped elements include a plurality of radial frames arranged along a direction from the central portion of the planar frame toward the outer edge,
The sloshing attenuation device according to any one of claims 1 to 7, wherein the attenuator is arranged along the radial frame. The plane frame includes a central member arranged at the center thereof,
The sloshing attenuation device according to claim 8, wherein at least two of the plurality of radial frames are connected to each other through the central member. The radial frame has a hollow pipe closed at both ends,
The sloshing damping device according to claim 8 or 9, wherein a sealed hollow space is formed inside the hollow pipe.   The sloshing damping device according to claim 10, wherein the hollow pipe is made of an extruded shape made of an aluminum alloy. The plurality of rod-shaped elements include a plurality of circumferential frames arranged to form a polygonal shape in plan view,
The sloshing attenuation device according to any one of claims 8 to 11, wherein the radial frame and the circumferential frame are joined. The circumferential frame has a hollow pipe closed at both ends,
The sloshing damping device according to claim 12, wherein a sealed hollow space is formed inside the hollow pipe.   The sloshing damping device according to claim 13, wherein the hollow pipe is made of an extruded shape made of an aluminum alloy.   The sloshing attenuation device according to any one of claims 12 to 14, wherein the plurality of peripheral frames include a plurality of outer peripheral frames that form an outline of the planar frame.   16. The sloshing damping device according to claim 15, wherein the float structure includes a guide member disposed outside a joint portion between the outer peripheral frames.   The sloshing attenuation device according to any one of claims 1 to 15, wherein the float structure includes a guide member disposed outside the planar frame.   The sloshing damping device according to claim 16 or 17, wherein the guide member has a sandwich panel including a core material made of a honeycomb core material or a collection of cylindrical bodies. A method of refurbishing an existing tank that improves the seismic resistance of the existing tank by constructing a sloshing damping device that damps the sloshing inside the existing tank with a floating roof,
Discharging the liquid stored in the existing tank and lowering the floating roof to secure a working space between the bottom surface of the existing tank and the floating roof; and from an inspection port provided in the existing tank Carrying a plurality of rod-shaped elements and an attenuation body for attenuating the flow velocity of the fluid into the working space;
A plurality of rod-shaped elements are combined inside the work space to construct a plane frame substantially parallel to the bottom surface of the existing tank, and the damping material is attached to the rod-shaped elements, so that sloshing is formed below the floating roof. And a step of constructing a damping device. A method for repairing an existing tank.

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