Manhole structure and storage tank for composite material full-liquid-receiving inner floating roof

Abstract

The utility model provides a manhole structure used on a composite material full-liquid-receiving inner floating roof and a storage tank, and relates to the field of fuel oil storage. The manhole structure comprises a manhole seat and a manhole cover, the manhole seat is provided with a first end face, a second end face and a manhole, the shortest distance of the cross section of the manhole is L1, and the longest distance of the cross section of the manhole is L2; the manhole cover comprises a cover body and a limiting assembly, the cover body selectively covers the first end face to seal the manhole, the limiting assembly comprises mutually connected fixing pieces and a rotating shaft rotationally connected with the cover body, the extending direction of the fixing pieces is parallel to the cross section of the manhole, and the length of the fixing pieces is set to be L3. L3 is larger than L1 so that the fixing piece can selectively abut against the second end face and restrain the cover body from being separated from the manhole seat, and L2 is larger than L3 so that the fixing piece can selectively be separated from the manhole seat from the first end face. The manhole structure is simple in structure, easy to operate, capable of rapidly and conveniently opening the cover plate and suitable for being installed on the composite material full-liquid-receiving inner floating roof.

Description

Technical Field

[0001] The present application relates to the field of fuel storage, and more particularly, to a manhole structure and a storage tank used on a composite material fully liquid-contact internal floating roof. Background Art

[0002] A manhole refers to an opening structure for personnel to enter and exit the equipment for installation, maintenance, and safety inspection. How to quickly open the manhole and reduce the time for personnel to be inside the object to be maintained has become a problem that needs to be actively solved. The traditional manhole structure used on the internal floating roof adopts a bolt-connected flange - cover plate. This kind of manhole structure takes a long time to loosen all the bolts and then open the cover plate, and it cannot quickly open the cover plate, resulting in relatively large potential safety hazards. Summary of the Utility Model

[0003] The purpose of the embodiments of the present application is to provide a manhole structure and a storage tank used on a composite material fully liquid-contact internal floating roof, which can quickly and conveniently open the cover plate and reduce the time for personnel to be inside the object to be maintained.

[0004] In a first aspect, the embodiments of the present application provide a manhole structure used on a composite material fully liquid-contact internal floating roof, which includes a manhole seat and a manhole cover.

[0005] The manhole seat is used to be installed in the installation hole of the composite material fully liquid-contact internal floating roof. The manhole seat has opposite first and second end faces, and a manhole penetrating through the first and second end faces. The first end face is used to extend out of the top wall of the composite material fully liquid-contact internal floating roof, and the second end face is used to extend out of the bottom wall of the composite material fully liquid-contact internal floating roof; the cross-section of the manhole remains unchanged from the first end face to the second end face, and the shortest distance of the cross-section of the manhole is set as L1 and the longest distance is set as L2;

[0006] The manhole cover includes a cover body and a limiting component. The cover body can selectively cover the first end face to close the manhole. The limiting component includes a connecting fixing member and a rotating shaft. The rotating shaft is rotatably connected to the cover body. The extending direction of the fixing member is parallel to the cross-section of the manhole. The length of the fixing member along its extending direction is set as L3, where L3 > L1, so that the fixing member can selectively abut against the second end face and prevent the cover body from detaching from the manhole seat, and L2 > L3, so that the fixing member can selectively disengage from the first end face of the manhole seat.

[0007] The manhole structure provided by the present application has a simple structure and simple operation. It can quickly lock and close the manhole from the outside (i.e., the side close to the top wall of the composite material fully liquid-contact internal floating roof), and quickly open the manhole, reduce the time for personnel to be inside the object to be maintained, reduce potential safety hazards, and at the same time can also reduce environmental pollution, reduce the user's operation cost, ensure the safe use of the storage tank, and is beneficial to improving the market competitiveness of the storage tank composite material fully liquid-contact internal floating roof product, having great practical significance in production.

[0008] In a possible implementation, the rotating shaft is slidably connected to the cover body; the limiting assembly includes a first limiting member located on the side of the cover body facing away from the fixing member, and the first limiting member is threadedly connected to the rotating shaft.

[0009] In the above implementation process, through the above settings, it is beneficial to quickly and conveniently rotate the rotating shaft, improve the opening efficiency of the cover body, reduce wear, and extend the service life of the manhole structure.

[0010] In a possible implementation, the limiting assembly includes a second limiting member and a third limiting member. The second limiting member is connected to the rotating shaft, the third limiting member is threadedly connected to the rotating shaft, the third limiting member is located on the side of the second limiting member facing away from the first limiting member, and the fixing member is slidably sleeved on the rotating shaft and is located between the second limiting member and the third limiting member.

[0011] In the above implementation process, through the mutual cooperation of the fixing member, the second limiting member and the third limiting member, the cover body can quickly open the manhole from both the outside and the inside. That is, the double-opening setting can better realize the opening and closing of the manhole, ensuring that maintenance personnel can quickly open the manhole whether from above or below the composite full-liquid-contact internal floating roof, realizing the simple and safe operation of the composite material manhole of the composite full-liquid-contact internal floating roof.

[0012] In a possible implementation, the cover body includes a cover body main body and a core body. The cover body main body is located outside the manhole seat, and the cover body main body can selectively cover the first end face to close the manhole seat; the core body is connected to the side of the cover body main body facing the first limiting member, and the core body protrudes from the cover body main body and is embedded in the manhole.

[0013] In the above implementation process, by introducing the core body to increase the volume of the cover body, when the manhole structure is installed in the composite full-liquid-contact internal floating roof storage tank, the oil and gas space between the composite full-liquid-contact internal floating roof and the medium can be reduced, which can effectively ensure the safe operation of the composite full-liquid-contact internal floating roof in the storage tank.

[0014] In a possible implementation, the interior of the core body has a porous structure.

[0015] In the above implementation process, due to the porous structure inside the core body, it is beneficial to reduce the weight of the cover body and facilitate the quick opening or closing of the manhole.

[0016] In a possible implementation, the manhole cover is provided with a through hole penetrating the cover body main body and the core body. The manhole structure further includes a bushing embedded in the through hole. The rotating shaft is rotatably and slidably inserted through the bushing, and an O-ring for sealing is provided between the rotating shaft and the bushing.

[0017] In the above implementation process, the above arrangement is not only conducive to the smooth rotation of the rotating shaft, but also ensures the air tightness between the rotating shaft and the manhole cover.

[0018] In a possible implementation manner, the manhole structure further includes a ladder, which is connected to the manhole seat and extends to a side of the manhole seat away from the manhole cover.

[0019] In a possible implementation, the manhole structure includes an inclined support member, one end of the support member is connected to the manhole seat, and the other end is connected to the ladder, and the support member, the ladder and the manhole seat together form a quasi-triangle.

[0020] In the above implementation process, the support rods are used to control the stability of the ladder, which is beneficial to improving the safety of maintenance personnel during the climbing process.

[0021] In a possible implementation manner, the first end surface is provided with a sealing gasket that cooperates with the cover body.

[0022] In the above implementation process, the density gasket is provided, which is conducive to better closing the manhole when the cover body is covered on the first end surface, thereby improving the sealing performance.

[0023] In a second aspect, an embodiment of the present application provides a storage tank, which includes a tank body, a composite material fully liquid-contacted internal floating roof located within the tank body, and a manhole structure provided by the first aspect of the present application. The composite material fully liquid-contacted internal floating roof is provided with a mounting hole, and a manhole seat is installed in the mounting hole. The first end face extends out of the top wall of the composite material fully liquid-contacted internal floating roof, and the second end face extends out of the bottom wall of the composite material fully liquid-contacted internal floating roof.

[0024] In the above implementation process, by installing the above manhole structure on the composite material fully liquid-connected internal floating roof, the cover body can be quickly locked and the manhole can be closed and the manhole can be quickly opened, reducing the time that personnel are in the tank body and reducing safety hazards. At the same time, it can also reduce environmental pollution, reduce user operating costs, and ensure the safe use of storage tanks. It is beneficial to improve the market competitiveness of composite material fully liquid-connected internal floating roof products for storage tanks, and has great production practice significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic assembly diagram of a composite material fully liquid-contacted internal floating roof and a manhole structure from a first perspective provided in an embodiment of the present application;

[0027] Figure 2 Schematic structural diagram of the manhole seat provided by an embodiment of the present application;

[0028] Figure 3 Assembly schematic diagram of the second perspective of the composite material fully wetted internal floating roof and the manhole structure provided by an embodiment of the present application.

[0029] Icon: 1000 - Composite material fully wetted internal floating roof; 2000 - Manhole structure; 20 - Manhole seat; 201 - First end face; 202 - Second end face; 203 - Manhole; 21 - Manhole cover; 22 - Cover body; 221 - Cover body main body; 222 - Core body; 231 - Rotating shaft; 2311 - Handle; 232 - Fixing member; 233 - First limiting member; 234 - Second limiting member; 235 - Third limiting member; 24 - Sleeve; 25 - O-ring seal; 26 - Sealing washer; 27 - Ladder; 271 - Column; 272 - Climbing rod; 28 - Support member. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0032] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0034] In the description of the present application, it should also be noted that unless otherwise clearly specified and defined, the terms "arrangement", "installation", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0035] The composite material fully wetted internal floating roof is an energy-saving and environmental protection device installed in a fixed roof storage tank and rising and falling with the liquid level change. The maintenance of the composite material fully wetted internal floating roof has always been the focus of attention in the industry. In view of this, the present application is hereby proposed.

[0036] The present application provides a storage tank, which includes a tank body, a composite material fully wetted internal floating roof located inside the tank body, and a manhole structure. The composite material fully wetted internal floating roof is provided with an installation hole.

[0037] Among them, the assembly relationship between the composite material fully wetted internal floating roof and the manhole structure is as Figures 1 to 3 shown.

[0038] Please refer to Figure 1 、 Figure 2 and Figure 3 , the manhole structure 2000 includes a manhole seat 20 and a manhole cover 21.

[0039] As Figure 1 and Figure 2 shown, the manhole seat 20 is used to be installed in the installation hole. The manhole seat 20 has opposite first end face 201 and second end face 202, wherein the first end face 201 extends out of the top wall of the composite material fully wetted internal floating roof 1000, and the second end face 202 extends out of the bottom wall of the composite material fully wetted internal floating roof 1000.

[0040] The manhole seat 20 has a manhole 203 penetrating through the first end face 201 and the second end face 202. The cross-section of the manhole 203 remains unchanged from the first end face 201 to the second end face 202. The shortest distance of the cross-section of the manhole 203 is set as L1, and the longest distance is set as L2.

[0041] The manhole cover 21 includes a cover body 22 and a limiting component. The cover body 22 can be selectively covered on the first end face 201 to close the manhole 203. The limiting component includes a connecting fixing member 232 and a rotating shaft 231. The rotating shaft 231 is rotatably connected to the cover body 22. The extending direction of the fixing member 232 is parallel to the cross-section of the manhole 203. The length of the fixing member 232 along its extending direction is set as L3, where L3 > L1, so that the fixing member 232 can selectively abut against the second end face 202 and prevent the cover body 22 from detaching from the manhole seat 20, and L2 > L3, so that the fixing member 232 can selectively disengage from the first end face 201 and the manhole seat 20.

[0042] It can be understood that the cross-section refers to the section along the direction perpendicular to the axial direction of the manhole 203.

[0043] It can be understood that since L2 > L3 > L1, that is, the shape of the cross-section of the manhole 203 is non-circular, but polygonal or elliptical, such as square, rectangle, etc. Exemplarily, when the cross-section of the manhole 203 is square, the shortest distance of the cross-section of the manhole 203 is the side length of the square, and the longest distance is the diagonal of the square. It should be noted that only the cross-section of the manhole 203 is limited here. The cross-section shape of the outer wall of the manhole seat 20 can be the same as or different from the cross-section shape of the manhole 203, and it is not limited here.

[0044] Under the above set conditions, during the actual use process, by rotating the rotating shaft 231, the fixing member 232 can be synchronously rotated to the position where the shortest distance of the cross-section is located and fit with the second end face 202. At this time, since L3 > L1, the fixing member 232 abuts against the second end face 202 and prevents the cover body 22 from detaching from the manhole seat 20, realizing that the cover body 22 quickly closes the first end face 201 to close the manhole 203.

[0045] When unlocking is required, the rotating shaft 231 can be directly rotated to make the fixing member 232 synchronously rotate to the position where the longest distance of the cross-section is located. At this time, since L2 > L3, by pulling the cover body 22 upward, the fixing member 232 can quickly pass through the manhole 203 and disengage from the first end face 201 and the manhole seat 20, realizing that the cover body 22 quickly detaches from the first end face 201 to open the manhole 203. That is, the difference between L2 and L3 can be designed according to actual needs, as long as the fixing member 232 can quickly pass through the manhole 203 and disengage from the first end face 201 and the manhole seat 20 when the fixing member 232 is synchronously rotated to the position where the longest distance of the cross-section is located.

[0046] The above-mentioned manhole structure 2000 is simple in structure and easy to operate. The cover body 22 can quickly lock and close the manhole 203 from the outside (that is, the side close to the top wall of the composite material fully liquid-connected internal floating roof 1000), and quickly open the manhole 203, thereby reducing the time that personnel are in the maintenance object and reducing safety hazards. At the same time, it can also reduce environmental pollution, reduce user operating costs, ensure the safe use of storage tanks, and is conducive to improving the market competitiveness of the composite material fully liquid-connected internal floating roof 1000 product of the storage tank, and has great production practice significance.

[0047] In order to facilitate the application of force to the rotating shaft 231 , a handle 2311 is provided on one side of the rotating shaft 231 outside the cover body 22 .

[0048] The fixing member 232 is, for example, a fixing rod.

[0049] It should be noted that the rotating shaft 231 and the cover body 22 can be fixedly connected or slidably connected.

[0050] like Figure 1 As shown, the rotating shaft 231 is slidably connected to the cover body 22 ; at this time, the limiting assembly includes a first limiting member 233 , the first limiting member 233 is located on the side of the cover body 22 away from the fixing member 232 , and the first limiting member 233 is threadedly connected to the rotating shaft 231 .

[0051] Since the rotating shaft 231 is slidably connected to the cover body 22, when the cover body 22 closes the manhole 203, the first limiter 233 is used to adjust the distance between the rotating shaft 231 and the fixing member 232 to control whether the fixing member 232 is against the second end surface 202.

[0052] Specifically, when the cover 22 closes the manhole 203, the first stopper 233 moves downward relative to the rotation axis 231 (toward the side of the fixing member 232) to shorten the distance between the rotation axis 231 and the fixing member 232 and the first stopper 233, so that the fixing member 232 and the second end face 202 are tightly abutted, thereby locking the cover 22 and the manhole seat 20, preventing the cover 22 from being separated from the manhole seat 20, and realizing the cover 22 to stably close the manhole 203. When it is necessary to open the manhole 203, the first stopper 233 moves upward relative to the rotation axis 231 (away from the side of the fixing member 232) to extend the distance between the rotation axis 231 and the fixing member 232 and the first stopper 233, so that the fixing member 232 and the second end face 202 are not tightly abutted and remain in a loose state, thereby facilitating the quick and convenient rotation of the rotation axis 231, improving the opening efficiency and reducing wear, and extending the service life of the manhole structure 2000.

[0053] It should be noted that the fixing member 232 may be fixedly connected to the rotating shaft 231 .

[0054] In actual use, it is necessary to realize that the manhole 203 is quickly opened or closed from the inner side (that is, the side close to the bottom wall of the composite material full liquid-contacted internal floating roof 1000) of the cover body 22. Figure 1 As shown, the limiting component includes a second limiting member 234 and a third limiting member 235. The second limiting member 234 is connected to the rotating shaft 231, and the third limiting member 235 is threadedly connected to the rotating shaft 231. The third limiting member 235 is located on the side of the second limiting member 234 away from the first limiting member 233. The fixing member 232 can be slidably mounted on the rotating shaft 231 and is located between the second limiting member 234 and the third limiting member 235.

[0055] By setting the second stopper 234 and the third stopper 235, the fixing member 232 can be stably clamped between the second stopper 234 and the third stopper 235, so that the cover 22 can stably close the manhole 203. When the cover 22 needs to be opened from the inside, since the third stopper 235 is threadedly connected to the rotating shaft 231, it is only necessary to disengage the third stopper 235 from the side of the rotating shaft 231 away from the cover 22, so that the fixing member 232 is disengaged from the rotating shaft 231 from the side of the rotating shaft 231 away from the cover 22, and then the cover 22 can be lifted from the bottom to the top to realize the rapid opening of the manhole 203 from the inside.

[0056] That is, through the cooperation of the fixing member 232, the second limiting member 234 and the third limiting member 235, the cover body 22 can quickly open the manhole 203 from both the outside and the inside, that is, the manhole structure 2000 can be double-opened.

[0057] That is, the manhole structure 2000 does not need to be fastened with multiple bolts to seal the manhole 203, and the double-opening structure can better realize the opening and closing of the manhole 203, ensuring that maintenance personnel can quickly open the manhole 203 regardless of whether they are above or below the composite material fully liquid-connected internal floating roof 1000.

[0058] The second position-limiting member 234 may be fixedly connected to the rotating shaft 231 , or may be threadedly connected to the rotating shaft 231 .

[0059] like Figure 1 As shown, the second limiting member 234 is threadedly connected to the rotating shaft 231 .

[0060] Exemplarily, the first limiting member 233 , the second limiting member 234 , and the third limiting member 235 are all nuts.

[0061] The cover body 22 may be in the shape of a plate with uniform thickness.

[0062] In some embodiments, the cover body 22 includes a cover body main body 221 and a core body 222. The cover body main body 221 is located outside the manhole seat 20, and the cover body main body 221 can be selectively covered on the first end face 201 to close the manhole seat 20. The core body 222 is connected to the side of the cover body main body 221 facing the first limiting member 233. The core body 222 protrudes from the cover body main body 221 and is embedded in the manhole 203.

[0063] Through the above arrangement of the core body 222, it is beneficial to increase the volume of the cover body 22 and reduce the oil and gas space between the composite fully wetted internal floating roof 1000 and the medium, which can effectively ensure the safe operation of the composite fully wetted internal floating roof 1000 in the storage tank.

[0064] The core body 222 can be made of solid material or hollow material.

[0065] As Figure 1 shown, the interior of the core body 222 has a porous structure.

[0066] It should be noted that the interior of the core body 222 having a porous structure means that only the interior of the core body 222 has a porous structure, and the outer surface of the core body 222 is a continuous surface, that is, the porous structure is not connected to the outside.

[0067] Exemplarily, the interior of the core body 222 is filled with honeycomb panels.

[0068] Through the above arrangement, it is beneficial to reduce the weight of the cover body 22 and facilitate the quick opening or closing of the manhole 203.

[0069] The materials of the cover body 22, the core body 222 and the manhole seat 20 can be metals, such as stainless steel, etc., or composite materials, such as fiberglass, etc. Those skilled in the art can design according to actual needs and are not limited herein.

[0070] It should be noted that since the interior of the core body 222 has a porous structure, that is, the cross-section is not smooth, therefore as Figure 1 shown, the manhole cover 21 is provided with a through hole penetrating the cover body main body 221 and the core body 222. The manhole structure 2000 further includes a bushing 24 embedded in the through hole. The rotating shaft 231 is rotatably and slidably inserted into the bushing 24, and an O-ring 25 for sealing is provided between the rotating shaft 231 and the bushing 24. Through the above arrangement, it is not only beneficial for the rotating shaft 231 to rotate smoothly, but also ensures the airtightness between the rotating shaft 231 and the manhole cover 21.

[0071] In order to further improve the sealing performance, the first end face 201 is provided with a sealing gasket 26 that cooperates with the cover body main body 221. The sealing gasket 26 is an annular elastic gasket, and the sealing gasket 26 is arranged on the first end face 201 along the circumference of the manhole 203.

[0072] like Figures 1 to 3 As shown, the manhole structure 2000 further includes a ladder 27 , which is connected to the manhole seat 20 , and extends to a side of the manhole seat 20 away from the manhole cover 21 .

[0073] The provision of the ladder 27 facilitates maintenance personnel to enter and perform maintenance.

[0074] The ladder 27 has two columns 271 and a plurality of climbing poles 272 disposed between the two columns 271 . The plurality of climbing poles 272 are arranged in parallel and at intervals along the extending direction of the columns 271 .

[0075] like Figure 3 As shown, the manhole structure 2000 includes an inclined support member 28, one end of the support member 28 is connected to the manhole seat 20, and the other end is connected to the ladder 27. The support member 28, the ladder 27 and the manhole seat 20 together form a triangle.

[0076] The support member 28, the ladder 27 and the manhole seat 20 together form a quasi-triangle to control the stability of the ladder 27, which is beneficial to improving the safety of maintenance personnel during the climbing process.

[0077] It can be understood that the number of support members 28 can be one or more. In this embodiment, the number of support rods is two, and the two support rods are arranged in parallel and corresponding to the two columns 271. One end of each support rod is connected to the corresponding column 271, and the other end is connected to the manhole seat 20.

[0078] It should be noted that the ladder 27 can be fixed to the manhole seat 20 by bolts, wherein one side of the bolt passing through the manhole seat 20 can be reinforced with a pad and then fixed with a nut, thereby facilitating a good support effect for maintenance personnel during the climbing process.

[0079] In summary, the manhole structure provided in the present application for use on the composite material fully liquid-connected internal floating roof has a simple structure and is easy to operate. The manhole can be quickly locked and closed, and the manhole can be quickly opened, thereby reducing the time personnel are in the maintenance object and reducing safety hazards. At the same time, it can also reduce environmental pollution, reduce user operating costs, and ensure the safe use of storage tanks. It is beneficial to improve the market competitiveness of composite material fully liquid-connected internal floating roof products and has great production practice significance.

[0080] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A manhole structure used in a composite material fully wetted internal floating roof, characterized in that, include: A manhole seat, used for being installed in the installation hole of the composite material fully liquid-contacted internal floating roof, the manhole seat having a first end face and a second end face opposite to each other, and a manhole penetrating the first end face and the second end face, the first end face being used for extending out of the top wall of the composite material fully liquid-contacted internal floating roof, and the second end face being used for extending out of the bottom wall of the composite material fully liquid-contacted internal floating roof; the cross section of the manhole remains unchanged from the first end face to the second end face, and the shortest distance of the cross section of the manhole is set as L1, and the longest distance is set as L2; and A manhole cover, comprising a cover body and a limiting assembly, wherein the cover body can be selectively covered on the first end surface to close the manhole, the limiting assembly comprises mutually connected fixing parts and a rotating shaft, the rotating shaft is rotatably connected to the cover body, the extension direction of the fixing part is parallel to the cross-section of the manhole, and the length of the fixing part along its extension direction is set to L3, wherein L3>L1, so that the fixing part can selectively abut against the second end surface and inhibit the cover body from detaching from the manhole seat, and L2>L3, so that the fixing part can selectively detach from the manhole seat from the first end surface.

2. The manhole structure according to claim 1, characterized in that, The rotating shaft is slidably connected to the cover body; The limiting assembly includes a first limiting member, the first limiting member is located at a side of the cover body away from the fixing member, and the first limiting member is threadedly connected to the rotating shaft.

3. The manhole structure according to claim 2, characterized in that, The limiting assembly includes a second limiting member and a third limiting member, the second limiting member is connected to the rotating shaft, the third limiting member is threadedly connected to the rotating shaft, the third limiting member is located on the side of the second limiting member away from the first limiting member, and the fixing member can be slidably mounted on the rotating shaft and is located between the second limiting member and the third limiting member.

4. The manhole structure according to any one of claims 1-3, characterized in that, The cover body comprises: a cover body, located outside the manhole seat, and the cover body can be selectively covered on the first end surface to close the manhole seat; and The core body is connected to the side of the cover body facing the first limiting member, and the core body protrudes from the cover body and is embedded in the manhole.

5. The manhole structure according to claim 4, characterized in that, The core has a porous structure inside.

6. The manhole structure according to claim 4, characterized in that, The manhole cover is provided with a through hole penetrating the cover body and the core body. The manhole structure also includes a sleeve embedded in the through hole. The rotating shaft is rotatably and slidably inserted into the sleeve. An O-ring for sealing is provided between the rotating shaft and the sleeve.

7. The manhole structure according to any one of claims 1-3, characterized in that, The manhole structure also includes a ladder, which is connected to the manhole seat and extends to a side of the manhole seat away from the manhole cover.

8. The manhole structure according to claim 7, characterized in that, The manhole structure comprises an inclined support member, one end of the support member is connected to the manhole seat, and the other end is connected to the ladder, and the support member, the ladder and the manhole seat together form a quasi-triangle.

9. The manhole structure according to any one of claims 1 to 3, characterized in that, The first end surface is provided with a sealing gasket matched with the cover body.

10. A storage tank, characterized in that, Comprising a tank body, a composite material fully liquid-contact internal floating roof located within the tank body, and a manhole structure as described in any one of claims 1-9, the composite material fully liquid-contact internal floating roof is provided with an installation hole, the manhole seat is installed in the installation hole, the first end face extends out of the top wall of the composite material fully liquid-contact internal floating roof, and the second end face extends out of the bottom wall of the composite material fully liquid-contact internal floating roof.

Images