Pre-tightening device for a vertical vessel top manhole inner pressure self-tight sealing structure

Abstract

The utility model provides a kind of vertical vessel top manhole inner pressure self-tight sealing structure pre-tightening device, the utility model includes spherical head and manhole connector, wherein, lower lug assembly, manhole cover plate assembly and pre-tightening power mechanism are provided on manhole connector, lower lug assembly includes first lug and second lug, manhole cover plate assembly includes cover plate and connecting assembly, manhole cover plate is arranged at the pipe orifice of manhole connector by connecting assembly and the side of manhole cover plate assembly towards manhole connector is provided with sealing structure, pre-tightening power mechanism includes electric chain hoist, the fixed end of electric chain hoist is hinged with lower lug assembly, and the output end of electric chain hoist is hinged with the other end of connecting assembly.The utility model is through electric chain hoist, the linkage mechanism and connecting point switching design of ingenuity, realize the unification of two functions of heavy cover plate hoisting and precision pre-tightening, simplify structure.

Description

Technical Field

[0001] This utility model relates to the field of pressure equipment manufacturing technology, and in particular to a pre-tightening device for a self-tightening sealing structure with internal pressure in the manhole at the top of a vertical container. Background Technology

[0002] Vertical vessels typically require manholes at the top for internal inspection, maintenance, and cleaning. Due to limitations in manufacturing and installation technology, existing manholes at the top of vertical vessels often employ forced sealing structures, such as flange bolt connections. This structure requires enormous bolt preload to tighten the sealing gaskets, making installation and disassembly time-consuming and labor-intensive. Furthermore, on large-diameter manholes, the required number of bolts and preload force result in bulky manhole covers and extremely inconvenient operation.

[0003] To overcome the drawbacks of forced sealing, internal pressure self-tightening sealing structures, such as Wood's seals and double cone seals, are widely used. These seals are characterized by a higher sealing specific pressure and better sealing effect with lower initial preload as the medium pressure increases. However, considering ease of manufacturing and installation, existing internal pressure self-tightening manhole structures are typically located in the lower middle part of the vessel body, with their opening direction perpendicular to the vessel's centerline (i.e., horizontally). This arrangement cannot meet the requirements of certain processes or structures that necessitate a manhole at the top of the vessel. Utility Model Content

[0004] To address the shortcomings mentioned above, this utility model provides a pre-tightening device that is compact in structure, easy to operate, and can reliably achieve self-tightening sealing of the manhole at the top of a vertical container.

[0005] To address the aforementioned problems, this utility model provides a pre-tightening device for a self-tightening sealing structure of a manhole at the top of a vertical container, comprising a spherical end cap and a manhole connector. The manhole connector is disposed on the spherical end cap. The manhole connector is equipped with a lower ear plate assembly, a manhole cover plate assembly, and a pre-tightening power mechanism. The lower ear plate assembly includes a first ear plate and a second ear plate, both fixedly mounted on the outer wall of the manhole connector. The manhole cover plate assembly includes a manhole cover plate and a connecting assembly. The manhole cover plate is disposed at the opening of the manhole connector via the connecting assembly, and a sealing structure is provided on the side of the manhole cover plate assembly facing the manhole connector. The pre-tightening power mechanism includes an electric chain hoist. The fixed end of the electric chain hoist is hinged to the lower ear plate assembly, and the output end of the electric chain hoist is hinged to the other end of the connecting assembly.

[0006] Preferably, the manhole connector is provided with a restraining ring and a threaded hole, and the manhole cover is provided with a double-ended stud. The bottom end of the double-ended stud is connected to the threaded hole on the manhole cover, and the top end of the double-ended stud penetrates the threaded hole on the restraining ring and is fixed by a nut.

[0007] Preferably, the spherical end cap is provided with a support frame, and an electric hand chain hoist is provided at the center of the support frame. The output end of the electric hand chain hoist is connected to the center of the manhole cover through a lifting chain.

[0008] Preferably, the restraining ring has a through hole at its center, through which the lifting chain passes, and the bottom end of the lifting chain is connected to the center of the manhole cover by a screw.

[0009] Preferably, the connecting assembly includes a strip-shaped connecting rod, the top end of which is hinged to the bottom end of the lifting chain via a pin, and the bottom end of which is hinged to a lifting lug on the manhole cover via a pin.

[0010] Preferably, the sealing structure includes a sealing groove and an O-ring rubber gasket. The sealing groove is provided on the end face of the manhole cover facing the manhole pipe, and the O-ring rubber gasket is embedded in the sealing groove.

[0011] Preferably, both the first ear plate and the second ear plate are made of two thick steel plates, and both the first ear plate and the second ear plate are welded to the lower part of the outer wall of the manhole pipe to form a fork-shaped structure.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. This utility model forms a precision linkage mechanism through the lower ear plate assembly, the connecting assembly, and the pre-tightening power mechanism. Through careful dimensional design of each hinge point, it can be ensured that when the electric hand chain hoist is in operation, the manhole cover is first lifted smoothly and accurately aligned with the manhole pipe. Then, in the final stage of closure, the sealing gasket area can evenly and accurately contact and press the sealing surface to form an effective initial seal, laying the foundation for the internal pressure self-tightening seal.

[0014] 2. This utility model is integrated on the outside of the manhole pipe, eliminating the need for additional bulky tools or complex hoisting equipment. The structure is very compact and does not occupy too much external space.

[0015] 3. This utility model uses an electric chain hoist to achieve the mechanization or automation of manhole opening and closing, greatly reducing the labor intensity of operators and improving work efficiency and safety. The operation process is flexible, stable, and reliable.

[0016] 4. This utility model ingeniously combines the pre-tightening requirement of the internal pressure self-tightening sealing structure with the special position of the top of the vertical container, successfully solving the technical problem of achieving self-tightening sealing at this position and expanding the application range of the internal pressure self-tightening sealing structure. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the structure of this utility model from direction A;

[0019] Figure 3 This is a schematic diagram of the structure at point B of this utility model. Detailed Implementation

[0020] To make the objectives, technical solutions and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and examples, but the examples given are not intended to limit the present utility model.

[0021] like Figures 1-3 As shown, an embodiment of this utility model includes a spherical end cap 1 and a manhole connector 2, with the manhole connector 2 disposed on the spherical end cap 1.

[0022] In this embodiment, the manhole connector 2 is provided with a lower ear plate assembly, a manhole cover plate assembly, and a pre-tightening power mechanism. The lower ear plate assembly includes a first ear plate 3 and a second ear plate 4. The first ear plate 3 and the second ear plate 4 are both fixedly installed on the outer wall of the manhole connector 2. The first ear plate 3 and the second ear plate 4 are both made of two thick steel plates, and the first ear plate 3 and the second ear plate 4 are both welded to the lower part of the outer wall of the manhole connector 2 to form a fork-shaped structure.

[0023] In this embodiment, the manhole cover assembly includes a manhole cover 5 and a connecting assembly. The manhole cover 5 is disposed at the opening of the manhole connector 2 via the connecting assembly, and a sealing structure is provided on the side of the manhole cover 5 facing the manhole connector 2. The connecting assembly includes a strip-shaped connecting rod 6, the top end of which is hinged to the bottom end of the lifting chain 7 via a pin, and the bottom end of which is hinged to the lifting lug on the manhole cover 5 via a pin. The sealing structure includes a sealing groove 8 and an O-ring rubber gasket 9. A sealing groove 8 is formed on the end face of the manhole cover 5 facing the manhole connector 2, and an O-ring rubber gasket 9 is embedded in the sealing groove 8.

[0024] In this embodiment, a restraining ring 10 is provided on the manhole connector 2 and a threaded hole is provided on the restraining ring 10. A double-ended stud 11 is provided on the manhole cover plate 5. The bottom end of the double-ended stud 11 is connected to the threaded hole on the manhole cover plate 5, and the top end of the double-ended stud 11 penetrates the threaded hole on the restraining ring 10 and is connected and fixed by a nut 12.

[0025] In this embodiment, the pre-tensioning power mechanism includes an electric manual hoist 13. A support frame 14 is provided on the spherical end cap 1, and the electric manual hoist 13 is located at the center of the support frame 14. The output end of the electric manual hoist 13 is connected to the center of the manhole cover 5 via a lifting chain 7. A through hole is provided at the center of the restraining ring 10, through which the lifting chain 7 passes, and the bottom end of the lifting chain 7 is connected to the center of the manhole cover 5 via screws.

[0026] In this embodiment, the device is mainly installed at the top center of the spherical head 1.

[0027] In this embodiment, its components and installation structure are as follows:

[0028] Manhole connector 2: Vertically welded to the top opening of the spherical head 1, it serves as the base for personnel entry and exit and equipment installation.

[0029] Manhole cover assembly: used for opening, closing and sealing manholes.

[0030] Manhole cover 5: Main structure, used to seal manholes.

[0031] Sealing structure: An annular sealing groove 8 is provided on the end face of the manhole cover plate 5 facing the manhole pipe 2. An O-ring rubber sealing gasket 9 is embedded in the sealing groove 8 to achieve sealing.

[0032] Lifting lug: It is located on the outer edge of the manhole cover 5 and is used for hinge.

[0033] In this embodiment, the lower ear plate assembly serves as a fixed base for the pre-tightening mechanism. It consists of a first ear plate 3 and a second ear plate 4, both made of thick steel plates and welded to the lower part of the outer wall of the manhole connector 2, forming two robust fork-shaped structures.

[0034] Pre-tensioning power mechanism: The core of this embodiment is an electric hand chain hoist 13, whose installation position and transmission method constitute the key innovation of this embodiment:

[0035] Electric chain hoist 13 installation point: The body of the electric chain hoist 13 is installed at the center of the support frame 14 independently set on the spherical end cap 1.

[0036] Power output of electric chain hoist 13: The output end (lifting chain 7) of electric chain hoist 13 is vertically downward.

[0037] The power transmission path of the electric chain hoist 13 is as follows: the bottom end of the lifting chain 7 is first hinged to the top end of a strip-shaped connecting rod 6 via a pin; subsequently, the bottom end of the strip-shaped connecting rod 6 is hinged to the lifting lug on the manhole cover 5 via another pin. This constitutes a unique "Z"-shaped linkage transmission system.

[0038] In this embodiment, the safety structure formed by the restraining ring 10 and the double-ended stud 11 is as follows:

[0039] The restraining ring 10 is fixedly installed on the manhole pipe 2, and the ring is provided with multiple threaded holes.

[0040] Double-ended stud 11: Its bottom end is screwed into the threaded hole around the manhole cover 5, and its top end passes upward through the threaded hole on the restraining ring 10 and is fixed with a nut. The main function of the double-ended stud 11 is to provide safety restraint and guidance, preventing the manhole cover 5 from accidentally falling during pre-tightening or maintenance.

[0041] Auxiliary lifting channel: To facilitate maintenance and respond to special situations, a through hole is provided at the center of the restraint ring 10. The lifting chain 7 of the electric hand chain hoist 13 passes through this through hole, and its end has the ability to be directly connected to the center of the manhole cover 5 by screws.

[0042] In this embodiment, the complete workflow is as follows:

[0043] (a) Manhole opening procedure, for example: when it is necessary to enter the container for maintenance.

[0044] Step 1: Release the pre-tight seal: The operator operates the control button of the electric hand chain hoist 13 to lower it and release the lifting chain 7.

[0045] Since the hoist body is fixed to the upper support frame 14, the release of the lifting chain 7 will cause the bar-shaped connecting rod 6 to loosen, thereby releasing the preload applied to the manhole cover 5 through the connecting rod mechanism. At this time, the weight of the manhole cover 5 is entirely borne by the safety structure composed of the double-ended stud 11 and the restraining ring 10.

[0046] Step 2: Change the connection mode from "pre-tightening mode" to "lifting mode".

[0047] The operator removes the pin connecting the top of the bar link 6, separating the bar link 6 from the lifting chain 7. Then, the bottom end of the lifting chain 7 is pulled downwards and securely connected to the center of the manhole cover 5 with screws.

[0048] Step 3: Loosen the safety system: Using a tool, loosen the nut 12 on the top of the double-ended stud 11 on the restraining ring 10 in sequence.

[0049] Step 4: Overall lifting and opening: The operator operates the control button of the electric hand chain hoist 13 to raise it.

[0050] The hoist begins to retract its chain, directly lifting the center point of the manhole cover 5 via the lifting chain 7, thus vertically raising the heavy manhole cover 5. The manhole cover 5 is smoothly lifted through the through hole in the center of the restraining ring 10, and is finally lifted away from the area of ​​the manhole connector 2, suspended at a sufficiently high and safe position, leaving the manhole passage completely clear.

[0051] (ii) Manhole closure and sealing process, after maintenance is completed.

[0052] Step 1: Centering and positioning: Operate the electric chain hoist 13 and slowly lower it to accurately place the manhole cover 5 downwards, so that it returns to directly above the manhole connector 2.

[0053] Align the bottom end of the guide stud 11 with the threaded hole on the manhole cover 5 and screw it in. At the same time, pass its top end through the threaded hole of the restraining ring 10 and initially tighten the nut 12 (do not tighten). At this time, the weight of the manhole cover 5 is mainly borne by the hoist.

[0054] Step 2: Transfer weight and switch modes: Gradually tighten the nut 12 on the restraining ring 10 of the double-ended stud 11 until the weight of the manhole cover 5 is completely borne by this safety structure.

[0055] Operate the hoist to slightly loosen the chain, then remove the connecting screws between the lifting chain 7 and the center of the manhole cover 5. Switch the connection mode back to "pre-tightening mode": reconnect the bottom end of the lifting chain 7 to the top end of the bar link 6 using a pin.

[0056] Step 3: Perform pre-tightening sealing: Operate the control button of the electric hand chain hoist 13 to raise it, the hoist retracts the lifting chain 7, and pulls the top of the bar-shaped connecting rod 6 upward.

[0057] Since the bottom end of the strip link 6 is hinged to the manhole cover 5, and the middle fulcrum is on the hinge system formed by the lower ear plate assembly, this action will drive the manhole cover 5 to produce a compound motion that both translates inward and presses downward.

[0058] This movement trajectory ensures that the manhole cover 5 can be precisely aligned and pressed against the manhole connector 2, so that the O-ring rubber gasket 9 is uniformly compressed to form an effective initial pre-seal. The pre-tightening force is provided by the electric chain hoist 13 and reliably maintained by its built-in brake.

[0059] Step 4: Preparation for Operation: After pre-sealing, the nuts of the double-ended studs 11 can be checked and tightened for the final step. When the medium is introduced into the container, the internal pressure will further press the manhole cover 5 from the back, causing the O-ring rubber gasket 9 to generate a greater sealing specific pressure, achieving a perfect internal pressure self-tightening sealing effect.

[0060] In this embodiment, the electric hand chain hoist 13 cleverly combines the lifting and precision pre-tightening functions of the heavy-duty cover plate by switching the linkage mechanism and connection point, thus simplifying the structure.

[0061] In this embodiment, the restraining ring 10 and the double-ended stud 11 provide crucial safety assurance. The entire process is mechanized, safe, and precise, perfectly solving problems such as the difficulty of operating heavy manholes on the top of vertical containers, inaccurate alignment, and inconvenient control of pre-tightening force, ensuring the reliability of the seal and greatly reducing operational risks and labor intensity.

[0062] Those skilled in the art can connect all electrical components and their compatible power supplies in this case via wires, and should select appropriate controllers according to actual conditions to meet control requirements. The specific connection and control sequence, and the sequential operation order between each electrical component to complete the electrical connection, are well-known technologies in the field, and will not be described further regarding electrical control.

[0063] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0064] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the technical solution of this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this patent application.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this patent application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0067] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pre-tightening device for a self-tightening sealing structure with internal pressure at the top manhole of a vertical container, comprising a spherical end cap and a manhole connector, wherein the manhole connector is disposed on the spherical end cap, characterized in that, The manhole connector is provided with a lower ear plate assembly, a manhole cover plate assembly, and a pre-tightening power mechanism. The lower ear plate assembly includes a first ear plate and a second ear plate, both of which are fixedly installed on the outer wall of the manhole connector. The manhole cover plate assembly includes a manhole cover plate and a connecting assembly. The manhole cover plate is set at the opening of the manhole connector through the connecting assembly, and the side of the manhole cover plate assembly facing the manhole connector has a sealing structure. The pre-tightening power mechanism includes an electric hand chain hoist. The fixed end of the electric hand chain hoist is hinged to the lower ear plate assembly, and the output end of the electric hand chain hoist is hinged to the other end of the connecting assembly.

2. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 1, characterized in that, The manhole connector is provided with a restraining ring and a threaded hole. The manhole cover is provided with a double-ended stud. The bottom end of the double-ended stud is connected to the threaded hole on the manhole cover, and the top end of the double-ended stud penetrates the threaded hole on the restraining ring and is fixed by a nut.

3. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 2, characterized in that, The spherical end cap is provided with a support frame, and an electric hand chain hoist is provided at the center of the support frame. The output end of the electric hand chain hoist is connected to the center of the manhole cover through a lifting chain.

4. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 3, characterized in that, The restraining ring has a through hole at its center, through which the lifting chain passes, and the bottom end of the lifting chain is connected to the center of the manhole cover by a screw.

5. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 4, characterized in that, The connecting assembly includes a strip-shaped connecting rod, the top end of which is hinged to the bottom end of the lifting chain via a pin, and the bottom end of which is hinged to a lifting lug on the manhole cover via a pin.

6. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 1, characterized in that, The sealing structure includes a sealing groove and an O-ring rubber gasket. The sealing groove is provided on the end face of the manhole cover facing the manhole pipe, and the O-ring rubber gasket is embedded in the sealing groove.

7. The pre-tightening device for the self-tightening sealing structure of the manhole at the top of a vertical container as described in claim 1, characterized in that, Both the first ear plate and the second ear plate are made of two thick steel plates, and both the first ear plate and the second ear plate are welded to the lower part of the outer wall of the manhole pipe to form a fork-shaped structure.

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