Rotation prevention mechanism for floating roof and resin molded component used therefor

Abstract

To provide a technique capable of satisfying performance requirements while preventing rotation of a floating roof with a simpler structure.SOLUTION: The rotation prevention mechanism of the floating roof includes a penetration member 10 provided to penetrate a pontoon 7 in the vertical direction, and a pair of bottleneck shapes arranged between the penetration member 10 and the 11b of a guide pole inside the penetration member 10 and having inner peripheral surfaces facing the outer peripheral surface of the 11b of the guide pole and having diameters reduced from both ends in the vertical direction toward the center. And a resin-molded component 12 held within a range (within a clearance CL) where the relative positional relationship between the inner peripheral surface of the floating roof and the outer peripheral surface of the 11b of the guide pole forms a buffer between the 11b of the guide pole and the penetration member 10 while preventing the rotation of the floating roof in the peripheral direction in both the horizontal state and the inclined state of the floating roof.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a floating roof rotation prevention mechanism used in a floating roof storage tank, and to a resin molded part suitable for use in a floating roof rotation prevention mechanism. [Background technology]

[0002] As prior art related to this type of anti-rotation mechanism for floating roofs, a commonly known structure is a penetration section in which a pole member (penetrating pole member) such as a gauge pole or guide ball penetrates the floating roof, allowing the floating roof to move up and down along the pole member while preventing its circumferential rotation (see, for example, Patent Document 1).

[0003] In this prior art, a pole member penetrates the center of a slide pipe that penetrates the floating roof's pontoon, and this pole member is sandwiched between tubular shaft sleeves on both sides in the circumferential direction to prevent the floating roof from rotating in the circumferential direction. Furthermore, when the floating roof moves up or down due to changes in the stored liquid level, the shaft sleeve contacts the pole member and rotates, guiding the floating roof's smooth up and down movement. Furthermore, the shaft sleeve is equipped with an extension mechanism that allows elastic movement in the circumferential direction, preventing damage to the pole member and shaft sleeve even when the stored liquid inside the tank sways during an earthquake, causing a sloshing state and causing the floating roof to move. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4523821 Summary of the Invention [Problem to be solved by the invention]

[0005] In the prior art described above, in addition to the sleeve with shaft, numerous other parts are required depending on the functions to be realized, such as the extension / retraction mechanism, the mounting frame to support these, and shaft bearings, resulting in a complex structure.

[0006] However, this does not mean that simply reducing the number of parts is sufficient; the penetration parts of the pole members in the pontoons must not only prevent the floating roof from rotating, but also must be able to move up and down relative to the pole members without resistance, not produce sparks when they come into contact with the pole members, and suppress vapor loss of the stored liquid from the penetration parts, among other performance requirements. Therefore, it is not easy to meet all performance requirements with a simple structure that simply reduces the number of parts.

[0007] Therefore, the present invention provides a technology that can prevent the rotation of a floating roof with a simpler structure while satisfying performance requirements. [Means for solving the problem]

[0008] The present invention employs the following solutions. Note that the parenthesized text in the following description is merely an example, and the present invention is not limited to this.

[0009] [First Invention] First, the present invention provides a mechanism for preventing rotation of a floating roof. This mechanism prevents circumferential rotation while allowing the floating roof to move up and down along a rod-shaped pole member (e.g., a guide ball, a gauge pole, etc.) installed vertically inside a floating roof storage tank, with the pole member penetrating the floating roof. Furthermore, the rotation prevention mechanism of the present invention is mainly composed of two components: a penetrating member and a resin-molded part. Each of these components will be explained below.

[0010] The penetrating member (e.g., a slide tube) is provided to penetrate the floating roof in the vertical direction, and can be a tubular member that moves up and down together with the floating roof with the pole member inserted therein. The inner diameter of the tubular penetrating member is set sufficiently larger than the outer diameter of the pole member to facilitate the up and down movement of the floating roof relative to the pole member and to avoid contact with the pole member even when the floating roof is in an inclined state.

[0011] The resin molded part is placed inside the penetrating member between the pole member and the penetrating member, and its inner peripheral surface facing the outer peripheral surface of the pole member has a distinctive shape. Specifically, this inner peripheral surface forms a pair of bottleneck shapes, tapering from both vertical ends toward the center. While a typical "bottleneck shape" narrows in only one direction, this "pair of bottleneck shapes" is characterized by the pair of shapes tapering from both vertical ends toward the center. A resin molded part with such an inner peripheral shape maintains the relative positional relationship between the inner peripheral surface and the outer peripheral surface of the pole member within a certain range, whether the floating roof is in a horizontal position (e.g., when the stored liquid level is horizontal and at rest) or an inclined position (e.g., when sloshing). Within this range, the floating roof prevents circumferential rotation while providing a buffer between the pole member and the floating roof.

[0012] [Horizontal position] For example, when the floating roof is in a horizontal position (not sloshing), the central axis of the penetrating member is nearly vertical, and the pole member penetrates the penetrating member in the vertical direction at a position approximately at the center (on the central axis) of the interior of the penetrating member. At this time, the resin molded part faces the outer peripheral surface of the pole member at the vertical center position where its inner peripheral surface narrows most into a pair of bottlenecks. The diameter of the inner peripheral surface (inner diameter) is set larger than the outer diameter of the pole member, and a distance (clearance) is provided between the inner peripheral surface and the outer peripheral surface that is sufficient to not impede the vertical movement of the floating roof relative to the pole member and to prevent circumferential rotation and radial movement of the floating roof. This prevents circumferential rotation of the floating roof while providing a buffer between the pole member and the penetrating member.

[0013] [Tilt state] On the other hand, when the stored liquid level fluctuates due to seismic motion and the floating roof becomes tilted (during sloshing), the resin molded part as well as the penetrating member become tilted relative to the pole member. However, because the inner surface forms a pair of bottleneck shapes as described above, the inner diameter of the inner surface widens from the center toward the top and bottom, and the pole member can be tilted relatively within the range of this inner diameter.

[0014] [Clearance setting] When the floating roof is in a horizontal position, a radial clearance of distance (b) is maintained between the inner peripheral surface of the molded resin part and the outer peripheral surface of the pole member. Meanwhile, when the floating roof is displaced from a horizontal position to a maximum tilt angle due to the sloshing of the stored liquid that can occur during seismic activity, the radial distance (a) by which the inner peripheral surface of the molded resin part approaches the outer peripheral surface of the pole member is kept within a range (b > a) that is less than the distance (b) in the horizontal position. Therefore, even when the floating roof is in a maximum tilt angle, a clearance of at least distance (ba) is maintained between the inner peripheral surface of the molded resin part and the outer peripheral surface of the pole member. This clearance is set according to the expected tilt angle of the floating roof due to liquid sloshing, and is large enough so that the outer peripheral surface of the pole member fits inside (does not come into contact with) the inner peripheral surface of the molded resin part even when the floating roof is in a maximum tilt angle. The assumed inclination angle of the floating roof is proportional to the design horizontal seismic intensity during liquid surface sloshing, and can be, for example, within the range of approximately 0° to 20°, but is not limited to this. Furthermore, the clearance value is set theoretically, and if there is a slight positional deviation from the theoretical value when the floating roof is inclined, it is possible that the inner surface of the resin molded part and the outer surface of the pole member will come into contact.

[0015] [Resin material] The resin molded parts are made of a resin material that is elastically deformable when it comes into contact with the pole members. Preferably, the resin material used should be one that cushions the impact while preventing the floating roof from rotating, does not interfere with the up and down movement (raising and lowering) of the floating roof, does not ignite when it comes into contact, is resistant to wear due to repeated contact, is easy to mold, does not deteriorate even when exposed to sunlight outdoors for long periods of time, and has high heat resistance (heat resistance temperature of 90°C or higher).

[0016] [Fixed structure] The penetrating member is a structure that penetrates the pontoon of the floating roof in the vertical direction, and the resin molded part can be structured so that both ends of the penetrating member in the vertical direction are fixed to positions where they protrude in the vertical direction from the top plate and bottom plate of the pontoon, respectively. This makes it possible to easily perform the work of fixing the resin molded part to the penetrating member (for example, by bonding, bolting, etc.) from above and below the pontoon.

[0017] [Liquid-tight structure] The resin molded part is preferably structured so that its lower end is fixed in a state where the space between it and the inner surface of the penetrating member is liquid-tightly sealed. This structure reduces the amount of stored liquid that enters the internal space of the penetrating member (the space from the liquid level of the stored liquid to the bottom end of the penetrating member) from the floating roof tank and adheres to the interior, reducing the burden of cleaning when maintaining the rotation prevention mechanism. It also prevents vapor loss of stored liquid from between the inner surface of the penetrating member and the resin molded part.

[0018] [Freely detachable structure] Furthermore, it is preferable that the resin molded part is detachably fixed to the penetrating member by fasteners (bolts, nuts, etc.). This improves workability during installation, maintenance, replacement, etc.

[0019] [Split structure] The resin molded part may be composed of a plurality of components that partially surround the outer circumferential surface of the pole member in the circumferential direction, and these components, when combined, surround the entire outer circumferential surface of the pole member inside the penetrating member, thereby forming a pair of bottleneck-shaped inner circumferential surfaces. This makes it possible to easily install a resin molded part in a position surrounding the outer peripheral surface of an existing pole member, for example, by sandwiching the pole member between multiple component parts.

[0020] [Partially overlapping structure] When a resin molded part is made up of multiple components, for example, by setting the circumferential length of each component to be greater than half the circumference, it is possible to create a structure in which parts of the components overlap in the circumferential direction when combined with each other, and these overlapping parts are positioned in areas where force is applied, such as the circumferential direction of the floating roof. This makes it possible to improve the durability (impact resistance, abrasion resistance, etc.) of the resin molded parts in positions where they are likely to come into contact with the pole members as the floating roof rotates.

[0021] [Setting diameter dimensions] The multiple components can be configured to include a first component whose area surrounding the outer surface of the pole member exceeds half on one side in the circumferential direction, and a second component whose area surrounding the outer surface also exceeds half on the other side in the circumferential direction, in which case the inner diameter of the inner surface of the first component is set larger than the outer diameter of the outer surface of the second component at all positions in the vertical direction. This allows the second component to be placed around the pole member so that it covers the outside of the first component without strain (deformation or stress), and it can cover the entire outer periphery of the pole member. Also, by positioning the overlapping part of the two in a part where force is applied, such as the circumferential direction of the floating roof, durability can be improved in the same way as above.

[0022] [Thickness setting] The resin molded part can be made of a resin material having a thickness that follows the bottleneck shape of the inner surface in the circumferential and vertical directions, and in this case, the resin material is set to have a thickness that is greater in areas where contact between the inner surface and the outer surface of the pole member may occur as the floating roof displaces relative to the pole member than in other areas. This improves the durability of the resin molded parts at positions where they are likely to come into contact with the pole members as the floating roof rotates, as described above.

[0023] [Double shell multi-layer structure] The resin molded part may be composed of a cylindrical outer shell and a pair of inner shells positioned inside the outer shell and forming a bottleneck shape along the inner circumferential surface in the vertical direction. This not only gives the resin molded part a single-layer structure with a high resin density and a hard solid layer, but also makes the outer shell a cylindrical solid layer and the inner shell a layer with a lower resin density than the outer solid layer and that is more likely to have curvature (bottleneck shape), making it possible to easily mold and process the inner surface shape of the resin molded part while ensuring overall strength.

[0024] [Second Invention] Second, the present invention provides a resin molded part. The resin molded part of the present invention can be used in a rotation prevention mechanism for a floating roof, and can be placed inside a tubular penetrating member that penetrates the floating roof in the vertical direction, whether the floating roof is already installed or is being newly installed. The resin molded part of the second invention can have all the configurations (structures) of the resin molded part described in the rotation prevention mechanism of the first invention above. [Effects of the Invention]

[0025] As described above, according to the present invention, it is possible to prevent the rotation of the floating roof with a simpler structure while satisfying performance requirements. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a vertical cross-sectional view of a floating roof storage tank 1 to which an embodiment of a rotation prevention mechanism and a resin molded part 12 used therein are applied. [Figure 2] 1A and 1B are a longitudinal cross-sectional view and a plan cross-sectional view of an anti-rotation mechanism according to an embodiment of the present invention; [Figure 3] 1 is a perspective view of a resin molded part 12 (a first component part 13 and a second component part 14) according to an embodiment. [Figure 4] 1 is an exploded perspective view of an example of an attached state of a resin molded part 12 (a first component part 13 and a second component part 14) according to an embodiment. FIG. [Figure 5] 1A to 1C are perspective views successively illustrating an example of a procedure for attaching a resin molded part 12 (a first component part 13 and a second component part 14) according to an embodiment. [Figure 6] FIG. 1 is a vertical cross-sectional view showing a floating roof storage tank 1 equipped with the structure of a conventional floating roof penetration part (rotation prevention device). [Figure 7] 7A and 7B are a plan view and a front view showing a detailed structure of a conventional floating roof penetration part (an enlarged view of part C in FIG. 6). DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, an open-type floating roof storage tank is used as an example, but the present invention may also be applied to a floating roof storage tank with a fixed roof (so-called inner float).

[0028] 1 is a vertical cross-sectional view of a floating roof tank 1 to which an anti-rotation mechanism according to one embodiment and a resin molded part 12 used therein are applied. Note that the structure of the floating roof tank 1 is already known, so it will be explained briefly below.

[0029] The floating roof tank 1 comprises a disk-shaped bottom plate 2, cylindrical side plates 3, and a floating roof 5 floating on the surface of the stored liquid 4. The floating roof 5 comprises a disk-shaped deck plate 6, and an annular pontoon 7 attached to the outer periphery of the deck plate 6. A sealing device 8 is provided around the entire periphery between the outer rim plate 7c of the pontoon 7 and the inner surface of the side plate 3, and a rain shield plate 9 is also provided around the entire periphery, covering the top of the sealing device 8. In addition, depending on the stored liquid 4, foam fire extinguishing equipment, foam dams, etc. may be provided, but these will not be discussed here.

[0030] [Rotation prevention mechanism] The anti-rotation mechanism for the floating roof 5 comprises a penetrating member 10 that penetrates the floating roof 5 in the vertical direction, and the penetrating member 10 is provided to penetrate the floating roof 5 in the vertical direction together with a pole member 11. In this embodiment, the anti-rotation mechanism is mainly composed of the penetrating member 10 and a resin molded part 12 provided inside it.

[0031] [Pole component] The pole member 11 is a rod-shaped (tubular) member extending vertically from the top of the floating roof tank 1 to the vicinity of the bottom plate 2 while being indirectly fixed to the side plate 3 via a floor called a gauging rafter 28 provided at the upper end of the side plate 3 and supports 29 protruding radially from the lower part of the side plate 3 toward the interior of the floating roof tank 1. The pole member 11 may include, for example, a gauge pole 11a and a guide pole 11b. The gauge pole 11a and the guide pole 11b are located at two locations on the same radial line (diameter) approximately 180° apart in the circumferential direction. Therefore, the anti-rotation mechanisms of this embodiment are also located at two locations on the same radial line approximately 180° apart in the circumferential direction, similar to the arrangement of the pole member 11. The two anti-rotation mechanisms can basically have the same structure except for the detailed design dimensions.

[0032] [Penetrating member (slide tube)] Although shown simply in FIG. 1 , the penetrating members 10 are, for example, made of tubular members, and are provided so that the entire penetrating members 10 penetrate the pontoon 7 in the vertical direction. The penetrating members 10 can also be called, for example, "slide pipes" because they move up and down together with the floating roof 5 relative to the pole members 11. The pole members 11 are inserted into the penetrating members 10, and the inner diameter of the penetrating members 10 is set to a size that allows a resin molded part 12 to be installed inside the penetrating members 10 with the pole members 11 inserted. The penetrating members 10 will be described in more detail below using another drawing.

[0033] [Resin molded parts (bottleneck-type resin parts)] Although also shown in a simplified form in FIG. 1 , the resin molded part 12 is disposed between the pole member 11 and the penetrating member 10, and has a pair of upper and lower bottleneck shapes with a constricted center in the vertical direction as a whole. The "pair of bottleneck shapes" here refers to the shape of the inner peripheral surface facing the outer peripheral surface of the pole member 11, and this inner peripheral surface has a pair of shapes that taper in diameter (inner diameter is reduced) from both ends in the vertical direction toward the center. Note that the resin molded part 12 can also be referred to as a "bottleneck-type resin part" due to the characteristic shape of its inner peripheral surface. The resin molded part 12 will also be described further below using other drawings.

[0034] [Structure of anti-rotation mechanism] Figure 2 shows a longitudinal cross-sectional view and a plan cross-sectional view of an embodiment of the rotation prevention mechanism. (a) in Figure 2 shows a longitudinal cross-sectional view of the floating roof 5 in its normal state (horizontal state), and (b) in Figure 2 shows a longitudinal cross-sectional view of the floating roof 5 when it is oscillating (tilted state). (c) in Figure 2 shows a plan cross-sectional view taken along the line AA in (a). Note that while the rotation prevention mechanism on the guide pole 11b side will be described as an example here, the same can be applied to the gauge pole 11a side, which is symmetrically positioned.

[0035] The pontoon 7 of the floating roof 5 is airtightly sealed inside by a pontoon top plate 7a, a pontoon bottom plate 7b, an outer rim plate 7c, and an inner rim plate 7d, and is also divided circumferentially into multiple chambers by bulkheads (not shown).

[0036] As described above, the penetrating member 10 has a vertical tubular shape, and the entire penetrating member 10 passes through one chamber of the pontoon 7 in the vertical direction, with its upper and lower ends protruding in the vertical direction from the pontoon top plate 7a and pontoon bottom plate 7b, respectively. A guide pole 11b is inserted vertically into the center of the penetrating member 10. The gap between the penetrating member 10 and the pontoon top plate 7a and pontoon bottom plate 7b is hermetically sealed by continuous welding or the like.

[0037] The resin-molded part 12 is disposed between the guide pole 11b inside the penetrating member 10, with its inner circumferential surface facing the outer circumferential surface of the guide pole 11b, and surrounds the guide pole 11b over almost the entire vertical area. In the example shown in the cross-sectional shape of Figures 2(a) and 2(b), the resin-molded part 12 has a single-layer structure molded to a substantially constant thickness over the entire vertical area, with an upper cylindrical portion 12a at its upper end, a constricted portion 12b at its central position, and a lower cylindrical portion 12c at its lower end. Of these, the upper cylindrical portion 12a and the lower cylindrical portion 12c are not tapered, but focusing on the constricted portion 12b, it can be seen that the inner diameter of the constricted portion 12b tapers from both the upper and lower ends toward the center, forming a pair of bottleneck shapes on the inner circumferential surface as a whole.

[0038] [Fixed structure] As shown in FIGS. 2(a) and 2(b), the resin-molded part 12 is fixed to the penetrating member 10 at the upper cylindrical portion 12a and the lower cylindrical portion 12c. Here, as an example, the resin-molded part 12 is detachably fixed using bolts and nuts 15 provided on the resin-molded part 12. For this purpose, bolt insertion holes (reference numerals omitted) are formed at the upper and lower ends of the penetrating member 10 at positions corresponding to the upper and lower cylindrical portions 12a and 12c of the resin-molded part 12, respectively. If an existing penetrating member 10 is used, appropriate hole drilling may be performed. Furthermore, the bolts of the bolts and nuts 15 do not have to be stud bolts fixed to the resin-molded part 12 as shown in FIG. 2. For example, the bolts may penetrate the resin-molded part 12. In this case, bolt insertion holes may also be formed in the upper and lower cylindrical portions 12a and 12c of the resin-molded part 12.

[0039] [Liquid-tight structure] The space between the penetrating member 10 and the lower cylindrical portion 12c is liquid-tightly sealed. Because the lower cylindrical portion 12c protrudes downward from the pontoon bottom plate 7b and is normally submerged in the stored liquid 4, ensuring a reliable seal prevents the stored liquid 4 from entering the space between the inner surface of the penetrating member 10 and the molded resin part 12 and reduces vapor loss of the stored liquid 4. This reduces the amount of stored liquid 4 that enters the space within the penetrating member 10 (the space from the liquid level of the stored liquid 4 to the lower end of the penetrating member 10) from the floating roof tank 1, thereby reducing the amount of stored liquid 4 adhering to the molded resin part 12 and easing the cleaning burden during maintenance of the molded resin part 12. The outer periphery of the lower cylindrical portion 12c may be bonded to the inner periphery of the penetrating member 10.

[0040] [Anti-rotation and shock-absorbing functions] The anti-rotation mechanism uses a resin molded part 12 provided inside the penetrating member 10 to prevent the floating roof 5 from rotating in the circumferential direction while providing a buffer between it and the guide pole 11b. In other words, due to the characteristic shape of the inner peripheral surface of the resin molded part 12, the relative positional relationship between its inner peripheral surface and the outer peripheral surface of the guide pole 11b is maintained within a certain range, whether the floating roof 5 is in a horizontal state (FIG. 2(a)) or an inclined state (FIG. 2(b)). This point will be explained further below.

[0041] [Horizontal position] When the floating roof 5 is in a horizontal position as shown in Figure 2(a), a clearance CL is provided in the radial direction between the inner peripheral surface of the resin molded part 12 (the constricted portion 12b) and the outer peripheral surface of the guide pole 11b. This clearance CL can be set to be approximately the same around the entire circumference of the guide pole 11b because the guide pole 11b stands upright, penetrating the interior of the penetrating member 10 in the vertical direction at approximately the center (on the central axis) and has the same diameter along its length. In this case, circumferential rotation and radial movement of the floating roof 5 are permitted within the range of clearance CL + α (α is the amount of elastic deformation of the resin molded part 12), but further rotation and movement are prevented.

[0042] [Tilt state] As shown in FIG. 2(b), the floating roof 5 can be tilted within the range of the above-mentioned clearance CL. Conversely, the size of the clearance CL is set so that the floating roof 5 can be tilted within the range of the inner diameter of the constricted portion 12b. Therefore, the clearance CL is set according to the expected inclination angle of the floating roof 5, and the size of the clearance CL is set within a range where the outer diameter of the guide pole 11b fits within the inner diameter of the constricted portion 12b even when the floating roof 5 is at its maximum inclination. In this embodiment, the expected inclination angle of the floating roof 5 is proportional to the design horizontal seismic intensity during liquid surface sloshing, and is in the range of approximately 0° to 20°, but is not limited to this.

[0043] [Setting criteria] In this way, the clearance CL is set based on the following criteria when the maximum inclination of the floating roof 5 is assumed. That is, if the distance (b) between the inner peripheral surface of the constricted portion 12b of the floating roof 5 in a horizontal state and the outer peripheral surface of the guide pole 11b is taken to be the size of the clearance CL, the theoretical size of the clearance CL is set based on the criteria that the distance (a) by which the inner peripheral surface of the constricted portion 12b approaches the outer peripheral surface of the guide pole 11b in the radial direction when the floating roof 5 is in an inclined state is kept within a range that is less than the distance (b) (b>a).

[0044] [Setting example] For example, when the sloshing angle generally determined from the design horizontal seismic intensity of a storage tank is θ, the radius of the inner circumferential surface of the constricted portion 12b is R, and the radius of the outer circumferential surface of the guide pole 11b is r, the distance (a) that the inner circumferential surface of the constricted portion 12b approaches the outer circumferential surface of the guide pole 11b when the tank is tilted is a=X sinθ 2 In this case, X in equation (1) is the distance for checking interference between constricted portion 12b and guide pole 11b, and is defined by equation (2) of X=R+b+r.

[0045] Whether the installation is existing or new, radius r is known from the outer diameter of guide pole 11b to be used. Therefore, for example, clearance CL = distance (b) can be temporarily determined first, and distance X can be calculated from equation (1) above under the condition that approach distance (a) during sloshing is less than distance (b) (b>a). Radius R can then be calculated from equation (2) above. Therefore, if the actual radius of the inner circumferential surface of constricted portion 12b is set (designed) to be equal to or less than radius R, approach distance (a) in an inclined state will not satisfy distance (b) = clearance CL, and it can be theoretically confirmed that the inner circumferential surface of constricted portion 12b will not come into contact with the outer circumferential surface of guide pole 11b even during sloshing.

[0046] [Resin material] The material used for the resin molded part 12 is a resin or the like that satisfies the following conditions: (1) it can elastically deform when it comes into contact with the steel guide pole 11b, (2) it prevents the rotation of the floating roof 5, (3) it does not interfere with the up and down movement (raising and lowering) of the floating roof 5, (4) it does not ignite when it comes into contact, (5) it does not wear down when it comes into contact repeatedly, (6) it is easy to process, (7) it does not deteriorate even when it is exposed to sunlight outdoors for a long period of time, and (8) it can withstand a certain amount of heat. Examples of such resins include Teflon (registered trademark: fluororesin, PTFE), synthetic rubber, and other wear-resistant resins.

[0047] [Material strength] Here, if the resin material is, for example, fiber-reinforced plastic and a medium level of strength and rigidity is required, a material strength of approximately 137 MPa in tensile strength can be selected. Comparing this with metal materials, for example, the tensile strength of carbon steel is approximately 400 MPa, that of brass is approximately 275 MPa, and that of AI alloy is approximately 260 MPa, it can be seen that the strength of the resin material is sufficient, although only slightly inferior to that of brass.

[0048] [Heat resistance] On the other hand, since fiber reinforced plastics basically melt due to the heat of a fire, it is preferable to use a resin material that is heat resistant to the extent that it will not melt even in the heat of a fire, or that will not cause any real damage even if it melts.

[0049] [Two-part structure] As shown in FIG. 2(c), the resin molded part 12 can be split into two pieces, each consisting of a plurality of first and second components 13 and 14. When a new anti-rotation mechanism is installed together with the floating roof storage tank 1, the guide pole 11b can be inserted into the resin molded part 12 in advance, even if the resin molded part 12 is an integrally molded part. However, in the case of an existing installation, the guide pole 11b is fixed, making it difficult to install the resin molded part 12 later if it is an integrally molded part. Therefore, in this embodiment, the resin molded part 12 is not formed into a complete shape in the circumferential direction, but is split into two pieces, the first component 13 and the second component 14, each with a 90° cutout at three-quarters of the circumference. The existing guide pole 11b is then sandwiched between the first component 13 and the second component 14, so that the entire resin molded part 12 covers the entire area (entire surface area) that the guide pole 11b contacts within the penetrating member 10.

[0050] The first component 13 and the second component 14 can be combined with each other with a difference in diameter. In the example of FIG. 2(c) (a plan cross-sectional view taken along the arrows A-A), the first component 13 is disposed on the radially outer side, and the second component 14 is fitted inside it and attached. For this reason, the inner diameter of the outer first component 13 is made slightly larger than the outer diameter of the inner second component 14. Furthermore, the overlapping portions of the first component 13 and the second component 14 can be fixed together with, for example, engaging tabs or fasteners (not shown). In FIG. 2(c), to facilitate understanding of the positional relationship, gaps (blank areas) are shown between the penetrating member 10 and the first component 13, between the penetrating member 10 and the second component 14, and between the first component 13 and the second component 14. However, in reality, these gaps are not present in the construction, and at the AA cross section, the first component 13 and the second component 14 (upper cylindrical portion 12a) are in close contact with the inner surface of the penetrating member 10, and the first component 13 and the second component 14 are also in close contact with each other. The first component 13 and the second component 14 may also be secured by pressure bonding with an adhesive, as in the sealing device 8 of the floating roof storage tank 1. Furthermore, each component may be divided into two halves of the circumference instead of three-quarters of the circumference, and the butt joints may be secured to each other.

[0051] As shown in Figure 2(c), positioning the overlapping portion of the first component 13 and the second component 14 in the circumferential direction of the floating roof 5 can improve resistance to contact with the guide pole 11b as the floating roof 5 rotates. Alternatively, positioning the overlapping portion in the radial direction can improve resistance to contact with the guide pole 11b as the floating roof 5 moves in the radial direction.

[0052] [Thickness setting] In the example of Figure 2, the resin molded part 12 (first component 13, second component 14) has the same thickness overall in the vertical and circumferential directions, but the thickness of the resin material may be made different in parts. Although not specifically shown, for example, in a part that comes into contact with the guide pole 11b frequently and is more susceptible to wear than other parts, the thickness of the resin material may be set to be thicker than in other parts. This prevents the resin material from becoming brittle due to uneven wear, and improves durability (impact resistance, wear resistance, etc.) while maintaining the performance of the rotation prevention mechanism over a long period of time.

[0053] [Double shell multi-layer structure] 2, the resin molded part 12 (first component 13, second component 14) is made of a single-layer resin material, but a multi-layer structure is also possible. Also (not shown), the resin molded part 12 can have a double-shell multi-layer structure consisting of an outer shell and an inner shell. The outer shell is made of a cylindrical solid layer with a relatively high resin density and hardness, while the inner shell is made of a resin material layer with a lower resin density than the solid layer and a curvature corresponding to the constricted portion 12b. This allows the resin molded part 12 (first component 13, second component 14) to have a double-shell multi-layer structure. This allows the outer shell to maintain overall strength, while the inner shell can easily be machined to form the curved surface (inner peripheral surface) of the constricted portion 12b.

[0054] [Cover member] As shown in Figures 2(a) and 2(b), a cover member 16 is attached to the upper opening of the penetrating member 10, closing the upper opening. The cover member 16 is not fixed to the penetrating member 10 but is configured to slide freely in the direction of arrow B along the upper opening surface (upper edge) of the penetrating member 10 in accordance with the inclination of the guide pole 11b. A hole 16a is formed in the center of the cover member 16, through which the guide pole 11b is inserted. The inner diameter of the hole 16a is set slightly larger than the outer diameter of the guide pole 11b (for example, approximately 10 mm larger than the outer diameter of the guide pole 11b). Therefore, when the floating roof 5 is inclined as shown in Figure 2(b), the cover member 16 slides along the guide pole 11b (first example). For this reason, the cover member 16 should be made of a non-sparking material such as brass, or a non-sparking material (not shown) should be installed at the contact point with the penetrating member 10. This, together with the constricted portion 12b of the resin molded part 12, enables the lid member 16 to further reduce vapor loss of the stored liquid 4 from the upper opening of the penetrating member 10. The outer diameter of the lid member 16 is set to a size that prevents the lid member 16 from shifting and falling when slid, and prevents the opening of the penetrating member 10 from being exposed.

[0055] As a second example, the cover member 16 may be fixed without sliding to follow the inclination of the guide pole 11b, and the inner diameter of the hole 16a may be enlarged more than in the above case, so that the relative inclination of the guide pole 11b is within the range of the inner diameter of the hole 16a. Even in this case, the inner peripheral surface of the constricted portion 12b is very close to the outer peripheral surface of the guide pole 11b, so that vapor loss of the stored liquid 4 can be sufficiently suppressed.

[0056] Fig. 3 is a perspective view of a resin molded part 12 according to one embodiment. Fig. 3(a) is an overall perspective view of the resin molded part 12, and Fig. 3(b) is an exploded perspective view of a first component 13 and a second component 14, which are split into two parts at three-quarters of the circumference. Fig. 3(c) is an overall perspective view of the first component 13 and the second component 14 sandwiching and attaching the pole member 11. Figs. 3(a), (b), and (c) are perspective views from different angles.

[0057] 3(a), the overall shape of the resin molded part 12 is such that the diameter is large at both ends in the longitudinal direction and then tapers toward the center, i.e., it has a shape resembling a pair of bottlenecks on both sides. While we are referring to the external shape here, because the inner circumferential surface has the pair of bottleneck shapes described above, this external shape would be obtained if the entire resin molded part 12 were made to have approximately the same thickness.

[0058] As shown in Figures 3(b) and 3(c), the first component 13 and the second component 14, which are split into two halves, can be attached by sandwiching the pole member 11 between them. Because the first component 13 and the second component 14 are each formed to cover three-quarters of the circumference, when the two are combined as shown in Figure 3(c), the first component 13 and the second component 14 can surround the entire circumference of the pole member 11. Furthermore, the inner second component 14 is exposed from the cutout range (90° portion) of the outer first component 13.

[0059] 4 is an exploded perspective view of an example of an attached resin molded part 12 (first component 13, second component 14) according to one embodiment. In this example, the following are shown in exploded form, from top to bottom along the center line O: the upper part of guide pole 11b, cover members 17 and 18, the upper part of pontoon top plate 7a and penetration member 10, inner second component 14, outer first component 13, the lower part of penetration member 10 and pontoon bottom plate 7b, and the lower part of guide pole 11b.

[0060] Furthermore, in this example, instead of the lid member 16 made of a single plate, the upper end opening of the penetrating member 10 is covered by lid members 17 and 18 made of two pieces. Each of the two lid members 17 and 18 is formed slightly larger than a semicircle, and when the lid members 17 and 18 are combined with each other and placed on the upper end opening of the penetrating member 10, these lid members 17 and 18 are in a partially overlapping state, and can collectively close the upper end opening of the penetrating member 10. This point will be described further below using another drawing.

[0061] [Work procedure] Next, the procedure for attaching the resin-molded part 12 to the guide pole 11b will be described. The following procedure can be applied to both existing and new installations. The same procedure can also be applied to attaching the resin-molded part 12 to the gauge pole 11a, which is located symmetrically to the guide pole 11b.

[0062] 5A to 5F are perspective views sequentially illustrating examples of the procedure for attaching the resin molded part 12 (the first component 13 and the second component 14) of one embodiment. The examples of the procedure for attaching the resin molded part 12 progress from (a) to (f) in FIG. 5.

[0063] Step (a): First, the resin molded part 12 is placed so as to sandwich the guide pole 11b. In practice, as described above, the guide pole 11b is placed between the inner second component part 14 and the outer first component part 13. In the following, to avoid complication, the first component part 13 and the second component part 14 are collectively referred to as the resin molded part 12.

[0064] Step (b): Next, the resin molded part 12 is lowered from above, for example, along the guide pole 11b, and inserted into the through-hole 7b1 of the pontoon bottom plate 7b. Although the illustration of the penetrating member 10 and the pontoon top plate 7a is omitted here, in reality, the resin molded part 12 is inserted into the inside of the penetrating member 10, and the resin molded part 12 is inserted into the through-hole 7b1 on the outside.

[0065] Step (c): Then, the penetrating member 10 and the resin-molded part 12 are fixed together with bolts and nuts 15 (arrows) in the circumferential direction. The pontoon top plate 7a is not shown here. In the case where the bolts of the bolts and nuts 15 are stud bolts that are pre-fixed to the resin-molded part 12, the stud bolts are inserted into the insertion holes of the penetrating member 10, and the nuts are tightened from the outside of the penetrating member 10 to secure the members together. Alternatively, in the case where bolt insertion holes are formed in both the penetrating member 10 and the resin-molded part 12, the bolts of the bolts and nuts 15 are inserted with the bolt insertion holes aligned, and the nuts of the bolts and nuts 15 are tightened from the inside of the resin-molded part 12 and the outside of the penetrating member 10 to secure the members together.

[0066] Step (d): This results in the resin molded part 12 being fixed inside the penetrating member 10. At this time, inside the penetrating member 10, the inner circumferential surface of the resin molded part 12 faces the outer circumferential surface of the guide pole 11b.

[0067] Step (e): Next, one of the two separate cover members 17, 18, ie, cover member 17, is placed on top of penetrating member 10 and resin molded part 12. Step (f): Then, the other lid member 18 is placed on one of the lid members 17 so that it overlaps a part of the other lid member 18, and the overlapping parts are fixed in place. The central parts of the lid members 17 and 18 form a hole (reference numeral omitted) through which the guide pole 11b is inserted.

[0068] [Application to existing facilities] As described above, the rotation prevention mechanism of this embodiment can also be applied to an existing floating roof 5 equipped with a conventional floating roof penetration section (rotation prevention device). Below, we will explain an example of installation when the rotation prevention mechanism of this embodiment is applied to an existing floating roof 5.

[0069] [Structure of existing storage tank] Figure 6 is a vertical cross-sectional view showing a floating roof storage tank 1 equipped with a conventional floating roof penetration section (rotation prevention device) structure. The conventional structure does not yet include the resin molded part 12 that constitutes the rotation prevention mechanism of this embodiment. However, apart from that, the basic overall structure, including the floating roof 5, is the same as that of the first embodiment (Figure 1). Therefore, in Figure 6, the same reference numerals are used to designate parts that are common to those of the first embodiment, and redundant explanations will be omitted.

[0070] [Detailed structure of the conventional example] Figure 7 is a plan view and a front view showing the detailed structure of a conventional floating roof penetration (an enlarged view of part C in Figure 6). Unlike the structure of the rotation prevention mechanism of the embodiment, in the case of the conventional floating roof penetration, a tubular sleeve 20 with a shaft made of brass (C2700T) or the like is provided on the upper part of the penetration member 10, which rotates in contact with the pole member 11. The attachment of the sleeve 20 with a shaft will be further explained below.

[0071] In the conventional example, the penetrating member 10 is tubular as in the first embodiment, but is provided at its upper end with a penetrating member flange 19 having a rectangular periphery. A rectangular slide plate 22 is provided above the penetrating member flange 19, and this slide plate 22 is slidable in the diameter direction relative to the penetrating member flange 19. A through hole 22a is formed in the center of the slide plate 22, and the pole member 11 is inserted through this through hole 22a.

[0072] A frame fixing member 26 is fixedly attached near each of the four corners of the upper part of the penetrating member flange 19, and a shaft mounting frame 23 is attached so as to span each of the two pairs of frame fixing members 26 that form in the circumferential direction of the floating roof 5. Therefore, the shaft mounting frames 23 form a pair in the diameter direction of the floating roof 5, and are positioned parallel to each other with the guide pole 11b sandwiched between them.

[0073] Two shaft bearings 21 are attached between the pair of shaft mounting frames 23 so as to span in parallel on both sides in the circumferential direction, sandwiching the pole member 11. Each of the pair of shaft mounting frames 23 is fixed to frame fixing material 26 with the outer surface of one side of the angle iron (angle iron) facing upward, and the shaft bearings 21 are fixed and attached via pillow blocks 24 at two locations on the top surfaces of the pair of shaft mounting frames 23.

[0074] The above-mentioned shaft-equipped sleeves 20 are attached to the two shaft bearings 21, respectively, so that a pair of shaft-equipped sleeves 20 are arranged in parallel on both sides of the circumferential direction of the pole member 11. At this time, the pair of shaft-equipped sleeves 20 are positioned so as to sandwich the pole members 11, such as the gauge pole 11a and guide pole 11b, between them from the circumferential direction of the floating roof 5.

[0075] As shown by arrow D in Figure 7, the floating roof 5 is not restricted in its radial movement within the horizontal plane by the shafted sleeve 20, and therefore, as the floating roof 5 moves, the position of the pole members 11 is displaced relatively together with the slide plate 22. On the other hand, the pole members 11, such as the gauge pole 11a and guide pole 11b, in combination with the action of the shafted sleeve 20 and slide plate 22, restrict the circumferential movement within the horizontal plane so that the floating roof 5 and pontoons 7 do not rotate.

[0076] A guide piece 27 made of brass plate (C2801P) or the like is fixed to the upper surface of the slide plate 22 with bolts and nuts 25 so as to sandwich the pole member 11 in the diametrical direction. As a result, when the pole member 11 moves relatively in conjunction with the diametrical movement of the floating roof 5, the guide piece 27 comes into contact with the pole member 11, and the slide plate 22 also moves following the pole member 11, but no sparks are generated by contact with the guide piece 27.

[0077] [Application of anti-rotation mechanism] When applying the rotation prevention mechanism of one embodiment to the structure of the floating roof penetration part of the conventional example as described above, all unnecessary parts are removed except for the existing pole member 11 and penetration member 10. In addition, the portions of the penetration member 10 that protrude upward from the pontoon top plate 7a and downward from the pontoon bottom plate 7b are cut or polished as appropriate to adjust the vertical length so that it corresponds to the length of the resin molded part 12, and insertion holes for the bolts and nuts 15 are drilled as appropriate.

[0078] After performing the above steps, the existing penetrating member 10 will be in a state such as that shown in the exploded oblique view of Figure 4. A new resin molded part 12 (first component 13 and second component 14) is placed inside this penetrating member 10 and fastened in place with bolts and nuts 15, and a cover member 16 (cover members 17, 18) is installed on the upper opening of the penetrating member 10, thereby installing an anti-rotation mechanism similar to that in one embodiment.

[0079] As a result, there is no need for a large number of parts (penetrating member flange 19, shaft-equipped sleeve 20, shaft bearing 21, slide plate 22, shaft mounting base 23, pillow block 24, bolts and nuts 25, base fixing material 26, guide piece 27, etc.) as in the conventional example, and by simply adding the resin molded part 12 and cover member 16 as new parts, it is possible to realize an anti-rotation mechanism with a simple structure and also to have all the necessary performance.

[0080] The rotation prevention mechanism for the floating roof 5 according to the embodiment described above provides the following advantages over the conventional example. (1) The main components are the penetrating member 10 and the resin molded part 12, and even if the cover member 16 (cover members 17, 18) is added to these, the number of parts such as the shaft-equipped sleeve and slide plate that were required in the conventional example can be reduced. Furthermore, in the case of a new installation, the main components can be the penetrating member 10 and the resin molded part 12 (cover member 16 added as needed) from the beginning, so the number of parts that need to be prepared can be kept to a minimum, and the structure at the time of completion can be simplified. (2) The first component 13 and the second component 14, which are split into two parts, can be attached by sandwiching them from two directions around the guide pole 11b. This makes it possible to easily attach or modify an existing floating roof 5 without having to remove the guide pole 11b, etc., which is highly convenient.

[0081] (3) Furthermore, the attachment portions (upper cylindrical portion 12a, lower cylindrical portion 12c) of the resin molded part 12 to the upper and lower penetrating member 10 also serve as the bushings of the conventional anti-rotation device (hollow cylindrical members that are fitted inside the penetrating member 10 and act as a buffer between the guide pole 11b and the penetrating member 10), eliminating the need for conventional bushings. Note that if the bolt holes for the bushings of the existing penetrating member 10 are used, there is no need to drill new bolt holes in the upper and lower protruding portions of the penetrating member 10.

[0082] (4) When the pontoon 7 of the floating roof storage tank 1 sways due to sloshing, the outer peripheral surface of the guide pole 11b and the inner peripheral surface of the constricted portion 12b of the resin molded part 12 come into contact over a wide area and undergo elastic deformation, preventing the floating roof 5 from rotating and reducing the load on the guide pole 11b. In addition, by bringing the guide pole 11b into contact with the constricted portion 12b of the resin molded part 12 over a wide area, it is also possible to scrape off the stored liquid adhering to the guide pole 11b.

[0083] (5) Since the structure has a clearance (distance) CL between the inner surface of the constricted portion 12b of the resin molded part 12 and the outer surface of the guide pole 11b, the guide pole 11b can be tilted relatively within the range of this clearance CL in accordance with the swaying of the floating roof 5, and the load on the guide pole 11b and the penetrating member 10 can be reduced even when the floating roof 5 sways.

[0084] (6) Furthermore, as is clear from the comparison between the front views of Figures 2(a) and 7, by appropriately adjusting the size of the clearance CL, the area of ​​the storage liquid 4 exposed to the atmosphere inside the penetrating member 10 can be made smaller than in the conventional case, and the amount of storage liquid 4 that evaporates can be reduced.

[0085] (7) The resin molded part 12 is detachably fixed to the penetrating member 10 with bolts and nuts 15, so that it can be easily replaced even if a defect is discovered during an open inspection of the floating roof storage tank 1.

[0086] (8) Furthermore, by selecting the resin material and structure used for the resin molded part 12, the strength and heat resistance of the rotation prevention mechanism including the resin molded part 12 can be improved.

[0087] Furthermore, even when one embodiment is considered as a single resin molded part 12, regardless of whether the floating roof storage tank 1 is new or existing, a rotation prevention mechanism can be easily realized by placing it inside a tubular penetrating member 10 that penetrates the floating roof 5 in the vertical direction.

[0088] The present invention is not limited to the above-described embodiment, and can be practiced in various modified forms.

[0089] The floating roof 5 in the embodiment is a so-called single-deck type, but the present invention may also be applied to a double-deck type. The positional relationship between the deck plate and the pontoons is not limited to the example given in the embodiment, and the shape of the pontoons is not particularly limited.

[0090] The penetrating member 10 may have a horizontal cross section that is not only circular but also elliptical or rectangular, as long as it can properly fix the resin molded part 12 inside. Even if the horizontal cross section is other than circular, the area where the stored liquid 4 is exposed to the atmosphere can be reduced by reliably sealing the space between the inside of the penetrating member 10 and the resin molded part 12.

[0091] Resin molded part 12 may be a single, integrally molded part, or may be composed of three or more components. Furthermore, resin molded part 12 may be composed of multiple components divided vertically, or may be divided into two parts, one above the other, with constricted part 12b at the center, or may be divided into three parts: upper cylindrical part 12a, constricted part 12b, and lower cylindrical part 12c.

[0092] Furthermore, the parts, members, etc. shown in the drawings are merely examples, and it goes without saying that the present invention can be implemented by appropriately modifying the sizes and materials of these parts. [Explanation of symbols]

[0093] 1 Floating roof storage tank 2 Bottom plate 3 Side Panel 4 Stock solution 5. Floating roof 6 Deck boards 7. Pontoon 7a Top plate 7a1 Through hole 7b Bottom plate 7b1 Through hole 7c outer rim plate 7d inner rim plate 8 Sealing device 9 Rain cover 10 Penetrating member (slide tube) 11 Pole components 11a Gauge Pole 11b Guide Pole 12 (Pair of bottleneck-type) plastic molded parts 12a Upper cylindrical part (of resin molded part) 12b Necked part (of a resin molded part) 12c Lower cylindrical part (of resin molded part) 13 (Outer) First Component 14 (inner) second component 15 bolts and nuts 16 Lid member 16a Hole 17 (One of) the cover members 18 (other) cover member 19 Penetration member flange 20 Sleeve with shaft 21 Shaft bearing 22 Slide plate 22a Through hole 23 Shaft mounting stand 24 Pillow Block 25 bolts and nuts 26 Mounting bracket fixing material 27 Guide Piece 28 Gauging Home 29 Support CL Clearance (spacing) O center line

Claims

1. A floating roof rotation prevention mechanism that prevents circumferential rotation while allowing the floating roof to move up and down along a rod-shaped pole member installed vertically inside a floating roof storage tank, with the floating roof penetrating the pole member, a tubular penetration member that penetrates the floating roof in the vertical direction and moves up and down together with the floating roof with the pole member inserted therein; A resin molded part that is arranged inside the penetrating member between the pole member, and has an inner peripheral surface facing the outer peripheral surface of the pole member, the inner peripheral surface of which is tapered from both ends in the vertical direction towards the center, forming a pair of bottleneck shapes, so that the relative positional relationship between the inner peripheral surface and the outer peripheral surface of the pole member is maintained within a range that acts as a buffer between the pole member and the penetrating member while preventing circumferential rotation of the floating roof, whether the floating roof is in a horizontal or inclined state. Floating roof anti-rotation mechanism.

2. The floating roof rotation prevention mechanism according to claim 1, The resin molded part is A floating roof rotation prevention mechanism characterized in that when the floating roof is in a horizontal state, there is a radial clearance of distance (b) between the inner circumferential surface and the outer circumferential surface of the pole member, and when the floating roof is displaced from a horizontal state to a state of maximum inclination due to the swaying of the stored liquid that can occur due to seismic motion, the radial distance (a) by which the inner circumferential surface approaches the outer circumferential surface of the pole member is kept within a range that is less than distance (b).

3. The floating roof rotation prevention mechanism according to claim 1 or 2, The resin molded part is A floating roof rotation prevention mechanism characterized by being made of a resin material that can elastically deform when in contact with the pole member.

4. The floating roof rotation prevention mechanism according to claim 1 or 2, The penetrating member is The floating roof pontoon is provided to penetrate the pontoon in the vertical direction, The resin molded part is A floating roof rotation prevention mechanism characterized in that both ends of the penetrating member in the vertical direction are fixed at positions protruding vertically from the top and bottom plates of the pontoon, respectively.

5. The floating roof rotation prevention mechanism according to claim 4, The resin molded part is A floating roof rotation prevention mechanism characterized in that the lower end is fixed in a liquid-tight seal with the inner surface of the penetrating member.

6. The floating roof rotation prevention mechanism according to claim 4, The resin molded part is A floating roof rotation prevention mechanism characterized in that it is detachably fixed to the penetrating member by a fastener.

7. The floating roof rotation prevention mechanism according to claim 1 or 2, The resin molded part is A floating roof rotation prevention mechanism characterized in that it is composed of multiple components that partially surround the outer peripheral surface of the pole member in the circumferential direction, and when these multiple components are combined, the entire outer peripheral surface of the pole member is surrounded inside the penetrating member, thereby forming the pair of bottleneck-shaped inner surfaces.

8. The floating roof rotation prevention mechanism according to claim 7, The plurality of components include: A floating roof rotation prevention mechanism characterized in that when assembled together, they overlap in part in the circumferential direction, and the overlapping part is located in the circumferential direction of the floating roof.

9. The floating roof rotation prevention mechanism according to claim 7, The plurality of components include: a first component whose range surrounding the outer circumferential surface of the pole member exceeds half on one side in the circumferential direction; a second component whose range surrounding the outer circumferential surface of the pole member exceeds half on either side in the circumferential direction; A floating roof rotation prevention mechanism characterized in that the inner diameter of the inner surface of the first component is set larger than the outer diameter of the outer surface of the second component at all positions in the vertical direction.

10. The floating roof rotation prevention mechanism according to claim 1 or 2, The resin molded part is The inner circumferential surface is made of a resin material having a thickness that conforms to the shape of the inner circumferential surface in the circumferential direction and the vertical direction. A floating roof rotation prevention mechanism characterized in that the resin material is designed so that the thickness of the part where contact between the inner surface and the outer surface of the pole member may occur due to displacement of the floating roof relative to the pole member is set to be greater than that of other parts.

11. The floating roof rotation prevention mechanism according to claim 1 or 2, The resin molded part is A floating roof rotation prevention mechanism characterized by being composed of a cylindrical outer shell and an inner shell located inside the outer shell and forming a pair of bottleneck-shaped inner shells along the inner surface in the vertical direction.

12. A resin molded part used in a floating roof rotation prevention mechanism, which prevents rotation in the circumferential direction and acts as a buffer between a rod-shaped pole member installed vertically inside a floating roof storage tank and a tubular penetrating member that penetrates the floating roof in the vertical direction, while allowing the floating roof to move up and down along the pole member, and which acts as a buffer between the penetrating member and the pole member, A resin molded part used in a rotation prevention mechanism for a floating roof, characterized in that it is arranged inside the penetrating member between the pole member, and the inner surface facing the outer surface of the pole member forms a pair of bottleneck shapes that taper in diameter from each end in the vertical direction toward the center, so that the relative positional relationship between the inner surface and the outer surface of the pole member is maintained within a range that provides a buffer between the pole member and the penetrating member while preventing circumferential rotation of the floating roof, whether the floating roof is in a horizontal or inclined position.

Images