A vertical high-temperature submersible pump bell jar seal structure

Abstract

The present application relates to the technical fields of vertical high-temperature submersible pump, in particular to a bell seal structure of vertical high-temperature submersible pump, comprising a pump shaft, an isolation cylinder, an enclosure seat, a packing gland assembly and a bell; the pump shaft penetrates the isolation cylinder and the packing gland assembly from bottom to top; a fit gap is formed between the isolation cylinder and the pump shaft; the enclosure seat is sleeved on the outside of the isolation cylinder, and the two form a containing cavity for containing molten salt of sealing medium; the packing gland assembly is fixedly connected with the enclosure seat, and the pump shaft is rotatably connected with the packing gland assembly; the bottom end of the bell is immersed in the molten salt of sealing medium, so that the containing cavity forms an outer cavity and an inner cavity, and the outer cavity and the inner cavity are communicated below the liquid level of the molten salt of sealing medium and isolated above the liquid level of the molten salt of sealing medium. The present application cooperates with a telescopic elastic sealing cylinder, the circumferential sealing and axial telescoping are borne by the elastic sealing cylinder, the spacing between the first sealing gasket and the second sealing gasket is adjusted and the compression sealing is realized.

Description

Technical Field

[0001] This invention relates to the field of vertical high-temperature submersible pump technology, specifically to a bell-shaped sealing structure for a vertical high-temperature submersible pump. Background Technology

[0002] Vertical high-temperature submersible pumps are widely used in applications involving the transport of high-temperature media. Their pump shafts typically need to rotate continuously under complex conditions such as high temperature, sealing media, and start-stop switching. Because there is a natural clearance where the pump shaft exits the pump body, improper sealing design can easily lead to media leakage, gas escape, and insufficient sealing reliability, thus affecting the safe operation and service life of the equipment.

[0003] In existing technologies, such as the bell-type sealing structure for a vertical high-temperature submersible pump disclosed in Chinese patent CN205714921U, components such as a bell, packing, and packing gland are arranged on the outside of the pump shaft. An adjusting mechanism drives the bell to press downwards along the pump shaft axis, causing the bell to press tightly against the graphite gasket, thus forming a static seal during shutdown and purging. During operation, the seal is achieved through the packing and sealing medium. Therefore, the sealing process of this type of solution relies on the axial displacement of components such as the bell or packing gland along the pump shaft, and the sealing effect is achieved through axial compression.

[0004] However, in actual operation, the packing gland assembly is more suitable for achieving continuous sealing only when the pump shaft is rotating, without needing to slide back and forth along the pump shaft axially. If axial displacement is still used to achieve sealing, it can easily lead to problems such as accelerated packing wear, unstable compression, and fluctuations in sealing performance. Summary of the Invention

[0005] The purpose of this invention is to provide a bell-shaped sealing structure for a vertical high-temperature submersible pump to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a bell-type sealing structure for a vertical high-temperature submersible pump, comprising a pump shaft, an isolation cylinder, a retaining seat, a packing gland assembly, and a bell;

[0007] The pump shaft passes through the isolation cylinder and the packing gland assembly from bottom to top;

[0008] A clearance is formed between the isolation sleeve and the pump shaft;

[0009] The enclosure seat is fitted onto the outside of the isolation cylinder, and the two work together to form a receiving cavity for containing the sealing medium molten salt;

[0010] The packing gland assembly is fixedly connected to the enclosure seat, and the pump shaft is rotatably and sealingly connected to the packing gland assembly;

[0011] The bottom of the bell jar is immersed in the molten salt of the sealing medium, so that the receiving cavity forms an outer cavity and an inner cavity. The outer cavity and the inner cavity are connected below the surface of the molten salt of the sealing medium and isolated above the surface of the molten salt of the sealing medium.

[0012] The top of the bell jar is located above the liquid surface of the sealing medium molten salt, and an elastic sealing cylinder is provided between it and the packing gland assembly;

[0013] The upper and lower ends of the elastic sealing cylinder are respectively sealed to the packing gland assembly and the bell jar, so that the top of the elastic sealing cylinder is isolated from the external environment through the packing gland assembly, and the bottom of the elastic sealing cylinder is connected to the inner cavity.

[0014] A second sealing gasket is fixedly installed at the top of the isolation cylinder, and the second sealing gasket is located above the liquid surface of the sealing medium molten salt;

[0015] The bell jar is connected to a first sealing gasket;

[0016] The first and second sealing gaskets are sequentially fitted around the pump shaft from top to bottom, and a connecting gap is formed between them to connect the fitting clearance and the inner cavity.

[0017] The elastic sealing cylinder can elastically elongate along its own axis under the action of the pushing mechanism, so that the first sealing gasket is pressed tightly onto the second sealing gasket to cut off the connecting gap.

[0018] Preferably, the interior of the elastic sealing cylinder is provided with an elastic connector, and the first sealing gasket is connected to the bell jar through the elastic connector.

[0019] Preferably, the bottom end of the elastic connector is fixedly connected to the bell jar, and the top end is fixedly connected to the connecting cylinder via a connecting cover. The first sealing gasket is fixedly connected to the bottom end of the connecting cylinder.

[0020] Preferably, the elastic sealing cylinder is a spiral metal bellows.

[0021] Preferably, the packing gland assembly is fixedly mounted on the enclosure seat by a first support frame;

[0022] The first support frame has a protrusion fixedly connected to its side. The protrusion includes a guide slope and a locking bottom surface.

[0023] A support rod is fixedly connected to the side of the bell jar, and the support rod extends horizontally to the top of the protrusion.

[0024] The pushing mechanism pushes the receiving rod downward, causing the elastic sealing cylinder to elastically extend along its own axis. As the receiving rod passes through the guide slope, it causes the elastic sealing cylinder to twist at a preset angle. Before the top surface of the receiving rod is flush with the bottom surface of the locking position, the first sealing gasket and the second sealing gasket make contact to achieve a seal. When the top surface of the receiving rod is flush with the bottom surface of the locking position, the elastic sealing cylinder returns from the twisted state to the non-twisted state under the action of the torsional restoring force, and causes the first sealing gasket and the second sealing gasket to rotate relative to each other.

[0025] Preferably, the first and second sealing gaskets make contact to achieve a seal before the receiving rod contacts the guide ramp.

[0026] Preferably, the actuating mechanism includes a guide sleeve, a guide rod, a horizontal push rod, an inclined push rod, and a telescopic drive component;

[0027] The telescopic drive component is fixedly installed on the top of the first support frame;

[0028] The guide sleeve is fixedly installed on the side of the first support frame, the guide rod slides vertically through the guide sleeve, and the top of the guide rod is connected to the telescopic drive component;

[0029] The horizontal push rod is fixed to the bottom end of the guide rod, and the inclined push rod is fixed to the horizontal push rod, forming a predetermined angle with the horizontal push rod;

[0030] The top surface of the push rod contacts the top surface of the receiving rod.

[0031] Preferably, the bottom of the first sealing gasket has a second conical surface, the top surface of the second sealing gasket has a first conical surface, and the first and second conical surfaces are matched.

[0032] Preferably, the enclosure includes a support plate and an outer cylinder, a heat insulation layer, a heating layer and an inner cylinder arranged sequentially from the outside to the inside;

[0033] The bottoms of the outer cylinder, insulation layer, heating layer, and inner cylinder are respectively fixedly connected to the support plate;

[0034] The bottom of the isolation cylinder penetrates the support plate;

[0035] The receiving cavity is located inside the inner cylinder.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] In this invention, the packing gland assembly is fixedly connected to a fixedly installed enclosure seat, thereby maintaining the packing gland assembly in a stable position relative to the pump shaft in the axial direction and preventing relative slippage along the pump shaft axially during sealing operations. Simultaneously, a retractable elastic sealing cylinder is used, which undertakes circumferential sealing and axial expansion / contraction, allowing adjustment of the gap between the first and second sealing gaskets and achieving a tight seal. Thus, on the one hand, the sealing gap adjustment is ensured, and on the other hand, axial slippage between the packing and the pump shaft is prevented, reducing axial friction and wear, and improving sealing stability and service life. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 This is a partial cross-sectional view of the front structure of the present invention;

[0040] Figure 3 This is a partial cross-sectional view of the present invention;

[0041] Figure 4 This is a three-dimensional structural schematic diagram showing a partial cross-section of the present invention;

[0042] Figure 5 This is a cross-sectional structural schematic diagram of the bell jar and elastic connector of the present invention;

[0043] Figure 6 This is a cross-sectional three-dimensional structural diagram of the second sealing gasket of the present invention;

[0044] Figure 7 This is a cross-sectional three-dimensional structural diagram of the first sealing gasket of the present invention;

[0045] Figure 8 This is a schematic diagram of the bell jar, elastic sealing cylinder, and pushing mechanism of the present invention;

[0046] Figure 9 This is a front view schematic diagram of the bell jar, elastic sealing cylinder, and pushing mechanism of the present invention;

[0047] Figure 10 This is a schematic diagram of the structure of the actuating mechanism of the present invention;

[0048] Figure 11 This is a schematic diagram of the structure of the actuator of the present invention from another perspective;

[0049] Figure 12 This is a partial structural schematic diagram of the actuating mechanism of the present invention;

[0050] Figure 13 This is a side view of the first support frame and the receiving rod of the present invention.

[0051] In the diagram: 1. Pump shaft; 2. Receiving cavity; 3. Support plate; 4. Outer cylinder; 5. Insulation layer; 6. Heating layer; 7. Inner cylinder; 8. Isolation cylinder; 9. Packing gland assembly; 10. Bell jar; 11. Elastic sealing cylinder; 12. First sealing gasket; 13. Second sealing gasket; 14. Elastic connector; 15. Connecting cover; 16. Connecting cylinder; 17. First mounting base; 18. Second mounting base; 19. First support frame; 20. Mounting frame; 21. Telescopic drive component; 22. First conical surface; 23. Second conical surface; 24. Second support frame; 25. Receiving rod; 26. Guide sleeve; 27. Guide rod; 28. Flat push rod; 29. ​​Angled push rod; 30. Protrusion; 31. Guide slope; 32. Locking bottom surface. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Please see Figures 1-13 The present invention provides a technical solution:

[0054] A bell-type sealing structure for a vertical high-temperature submersible pump includes a pump shaft 1, an isolation cylinder 8, a retaining seat, a packing gland assembly 9, and a bell 10; the pump shaft 1 passes through the isolation cylinder 8 and the packing gland assembly 9 sequentially from bottom to top.

[0055] Pump shaft 1 is the drive shaft used to transmit power in a high-temperature submersible pump.

[0056] The isolation cylinder 8 is cylindrical and is coaxially sleeved on the outside of the pump shaft 1, forming a fitting clearance between the isolation cylinder 8 and the pump shaft 1.

[0057] The enclosure seat is fitted on the outside of the isolation cylinder 8, and the two work together to form a receiving cavity 2 for containing the sealing medium molten salt.

[0058] Specifically, the enclosure includes a support plate 3 and, from the outside in, an outer cylinder 4, a heat insulation layer 5, a heating layer 6, and an inner cylinder 7 arranged sequentially. The bottoms of the outer cylinder 4, the heat insulation layer 5, the heating layer 6, and the inner cylinder 7 are fixedly connected to the support plate 3. The bottom end of the isolation cylinder 8 penetrates through the support plate 3. The receiving cavity 2 is located inside the inner cylinder 7. The heating layer 6 is used to heat the sealing medium molten salt, and the heat insulation layer 5 is used to reduce the rate of heat loss.

[0059] The packing gland assembly 9 is fixedly connected to the enclosure seat, and the pump shaft 1 is rotatably sealed to the packing gland assembly 9. The packing gland assembly 9 mainly relies on its internally designed sealing packing to achieve a sealed connection with the pump shaft 1, and the pump shaft 1 can rotate relative to the packing gland assembly 9.

[0060] The bottom end of the bell jar 10 is immersed in the molten salt sealing medium, so that the receiving cavity 2 forms an outer cavity and an inner cavity. The outer cavity and the inner cavity are connected below the surface of the molten salt sealing medium and isolated above the surface of the molten salt sealing medium; specifically, in conjunction with Figure 2 and Figure 3 Sufficient gap is left between the bottom of the bell jar 10 and the support plate 3 so that the outer cavity and the inner cavity are connected below the surface of the sealing medium molten salt liquid.

[0061] In this technical solution, the top of the bell jar 10 is located above the liquid surface of the sealing medium molten salt, and an elastic sealing cylinder 11 is provided between it and the packing gland assembly 9. The elastic sealing cylinder 11 has the ability to expand and contract axially and to seal circumferentially. While it expands and contracts along its own axis, it can ensure its circumferential sealing performance. Together with the packing gland assembly 9, it can achieve a sealed connection between the inner cavity and the external environment, preventing air or impurities in the external environment from entering the fitting gap and the interior of the inner cavity.

[0062] The upper and lower ends of the elastic sealing cylinder 11 are respectively sealed to the packing gland assembly 9 and the bell jar 10. For example, in this embodiment, the upper and lower ends of the elastic sealing cylinder 11 can be sealed to the packing gland assembly 9 and the bell jar 10 by welding, so that the top end of the elastic sealing cylinder 11 is isolated from the external environment through the packing gland assembly 9, and the bottom end of the elastic sealing cylinder 11 is connected to the inner cavity, so that air or impurities in the external environment cannot enter the interior of the elastic sealing cylinder 11.

[0063] In this embodiment, a second sealing gasket 13 is fixedly provided on the top of the isolation cylinder 8, and the second sealing gasket 13 is located above the liquid surface of the sealing medium molten salt; specifically, a second mounting base 18 is welded and fixed on the top of the isolation cylinder 8, and the second sealing gasket 13 is installed in the annular groove opened on the top surface of the second mounting base 18.

[0064] A first sealing gasket 12 is connected to the bell jar 10; specifically, the first sealing gasket 12 is fixedly installed on the first mounting base 17, and then the first mounting base 17 is connected to the bell jar 10. The specific connection method is described in detail below.

[0065] In this embodiment, the first sealing gasket 12 and the second sealing gasket 13 are sequentially sleeved around the pump shaft 1 from top to bottom, and a connecting gap is formed between them to connect the mating clearance and the inner cavity; specifically, in such a way... Figure 2 , Figure 3In the indicated state, the first sealing gasket 12 and the second sealing gasket 13 form an open communication gap, allowing communication between the mating clearance and the inner cavity. Furthermore, in this state, the pump shaft 1 is rotating, and the vertical high-temperature submersible pump is in operation.

[0066] The first sealing gasket 12 and the second sealing gasket 13 can be graphite gaskets.

[0067] When nitrogen purging is required, the elastic sealing cylinder 11 can elastically extend along its own axis under the action of the pushing mechanism, so that the first sealing gasket 12 is pressed against the second sealing gasket 13 to cut off the connecting gap. At this time, the sealing connection between the first sealing gasket 12 and the second sealing gasket 13 can prevent nitrogen from entering the inner cavity and ensure that the sealing medium molten salt will not overflow due to nitrogen purging.

[0068] In this technical solution, the packing gland assembly 9 is fixedly connected to the fixedly installed enclosure seat, thereby keeping the packing gland assembly 9 in a stable position relative to the pump shaft 1 in the axial direction and preventing relative slippage of the packing gland assembly 9 along the pump shaft 1 during sealing operations. Simultaneously, in conjunction with the retractable elastic sealing cylinder 11, the elastic sealing cylinder 11 undertakes circumferential sealing and axial expansion, allowing adjustment of the gap between the first sealing gasket 12 and the second sealing gasket 13 and achieving a tight seal. Thus, on the one hand, the sealing gap adjustment is ensured, and on the other hand, axial slippage between the packing and the pump shaft 1 is prevented, reducing axial friction and wear, which is beneficial to improving sealing stability and service life.

[0069] In this technical solution, an elastic connector 14 is provided inside the elastic sealing cylinder 11. Specifically, in this embodiment, the elastic connector 14 is a metal bellows. The first sealing gasket 12 is connected to the bell jar 10 through the elastic connector 14. Thus, an elastic compression seal can be achieved between the first sealing gasket 12 and the second sealing gasket 13, so that the first sealing gasket 12 and the second sealing gasket 13 form a continuous and uniform surface contact seal, thereby compensating for manufacturing errors, assembly deviations, and dimensional changes caused by thermal expansion and contraction, and improving the initial sealing reliability and long-term sealing stability.

[0070] Furthermore, in this technical solution, such as Figures 2-4 As shown, the bottom end of the elastic connector 14 is fixedly connected to the bell jar 10, for example, by welding. The top end of the elastic connector 14 is fixedly connected to the connecting cylinder 16 via the connecting cover 15, which can also be fixedly connected by welding.

[0071] The first sealing gasket 12 is fixedly connected to the bottom end of the connecting cylinder 16. Specifically, the first mounting base 17 for installing the first sealing gasket 12 is welded and fixed to the bottom end of the connecting cylinder 16.

[0072] The elastic connector 14 is kept in a stretched state under the support of the second sealing gasket 13 and applies axial clamping force to the first sealing gasket 12, which can make the first sealing gasket 12 and the second sealing gasket 13 form a stable compression seal; at the same time, when the elastic connector 14 is stretched axially, its elastic force acts basically along its own axis, thereby improving the directional stability of the clamping action.

[0073] In this embodiment, the elastic sealing cylinder 11 is a spiral metal bellows. The spiral metal bellows can be stretched in a limited axial direction and can also be twisted within a small angle range. For example, in this embodiment, the bottom end of the spiral metal bellows can be twisted relative to the top end within an angle range of 1-3° without causing damage to the spiral metal bellows itself.

[0074] In this technical solution, the packing gland assembly 9 is fixedly installed on the enclosure seat by a first support frame 19. Specifically, in this embodiment, the bottom end of the first support frame 19 can be fixed to the top of the inner cylinder 7 by welding; the top end of the first support frame 19 can be installed on the packing gland assembly 9 by bolts. In this embodiment, two first support frames 19 are provided and are evenly distributed around the circumference of the packing gland assembly 9.

[0075] The first support frame 19 is fixedly connected to a protrusion 30 on its side. In this embodiment, the cross-sectional shape of the protrusion 30 is a right triangle. The protrusion 30 includes a guide slope 31 and a locking bottom surface 32.

[0076] A receiving rod 25 is fixedly connected to the side of the bell jar 10. Specifically, in this embodiment, a second support frame 24 is welded and fixed to the side of the bell jar 10, and the receiving rod 25 is welded and fixed to the top of the second support frame 24. Furthermore, the receiving rod 25 extends horizontally to directly above the protrusion 30.

[0077] The pushing mechanism pushes the receiving rod 25 downward, causing the elastic sealing cylinder 11 to elastically extend along its own axis, ultimately causing the first sealing gasket 12 and the second sealing gasket 13 to be squeezed and sealed together.

[0078] As the receiving rod 25 passes through the guide slope 31, the elastic sealing cylinder 11 also moves downwards by stretching. Therefore, the direction of its rebound force is consistent with its own axial direction. Based on this, when the receiving rod 25 slides past the guide slope 31, it can cause the bottom end of the elastic sealing cylinder 11 to twist at a preset angle, for example, the bottom end of the elastic sealing cylinder 11 twists 1° relative to its top end. During the twisting process, the elastic sealing cylinder 11 will always maintain axial extension. During the twisting process, the top center and bottom center of the elastic sealing cylinder 11 can still be arranged around the same central axis, or in other words, basically maintain a coaxial setting. Similarly, during the process of returning from a torsional state to a non-torsional state, the top and bottom centers of the elastic sealing cylinder 11 can generally still be arranged around the same central axis, or in other words, remain basically coaxial. Therefore, when the top surface of the receiving rod 25 is flush with the bottom surface 32 of the locking position, the elastic sealing cylinder 11 returns from a torsional state to a non-torsional state under the action of torsional restoring force. That is, the bottom end of the elastic sealing cylinder 11 will rotate, thereby driving the first sealing gasket 12 and the second sealing gasket 13 to rotate relative to each other. Of course, this is based on the following condition: before the top surface of the receiving rod 25 is flush with the bottom surface 32 of the locking position, the first sealing gasket 12 and the second sealing gasket 13 complete contact to achieve sealing. When the first sealing gasket 12 and the second sealing gasket 13 rotate in one direction, the contact surfaces of the two can gradually complete alignment and running-in in the same direction, promoting the uniform wear of local high points and forming a continuous and stable contact surface, thereby improving the initial contact state, reducing local off-center load and stress concentration on the sealing surface, and improving the uniformity and stability of the sealing contact.

[0079] Furthermore, in this embodiment, the first sealing gasket 12 and the second sealing gasket 13 make contact to achieve a seal before the receiving rod 25 contacts the guide slope 31. Structurally, this means that the downward stroke of the receiving rod 25 as it moves downward and contacts the guide slope 31 is greater than the distance between the first sealing gasket 12 and the second sealing gasket 13. Its beneficial effects are as follows: the first sealing gasket 12 and the second sealing gasket 13 have already made contact before the elastic sealing cylinder 11 is twisted. Then, the twisting of the elastic sealing cylinder 11 forms the first relative rotation between the first sealing gasket 12 and the second sealing gasket 13. The recovery process after the elastic sealing cylinder 11 is twisted forms the second relative rotation between the first sealing gasket 12 and the second sealing gasket 13. The two relative rotations are in opposite directions, that is, a reciprocating relative rotation is completed. This allows the contact surfaces of the first sealing gasket 12 and the second sealing gasket 13 to complete alignment, running-in and uniform pressing in opposite directions in sequence. This helps to correct the uneven pressure areas, reduce the risk of contact misalignment and displacement, and improve the uniformity of the fit and sealing stability between the first sealing gasket 12 and the second sealing gasket 13, thereby enhancing the reliability and continuity of the sealing effect.

[0080] In some embodiments, a second conical surface 23 is formed at the bottom of the first sealing gasket 12, and a first conical surface 22 is formed on the top surface of the second sealing gasket 13, and the first conical surface 22 and the second conical surface 23 are matched.

[0081] In this technical solution, the pushing mechanism includes a guide sleeve 26, a guide rod 27, a horizontal push rod 28, an inclined push rod 29, and a telescopic drive component 21; wherein, the guide sleeve 26 is used to limit the movement direction of the guide rod 27, so that the guide rod 27 can only move vertically.

[0082] The top of the first support frame 19 is fixed to the mounting frame 20 by bolts or welding, and the telescopic drive component 21 is installed on the mounting frame 20 by bolts.

[0083] The telescopic drive component 21 is fixedly installed on the top of the first support frame 19; in this embodiment, the telescopic drive component 21 can be selected from one of an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder.

[0084] The guide sleeve 26 is fixedly installed on the side of the first support frame 19, and the guide rod 27 slides vertically through the guide sleeve 26, and the top end of the guide rod 27 is connected to the telescopic drive member 21; for example, the top end of the guide rod 27 and the output shaft of the telescopic drive member 21 can be connected by a thread.

[0085] The horizontal push rod 28 is fixed to the bottom end of the guide rod 27, and the inclined push rod 29 is fixed to the horizontal push rod 28, forming a predetermined angle with the horizontal push rod 28; the size of this predetermined angle is not limited and can be adjusted adaptively according to the actual situation. For example, in this embodiment, the predetermined angle can be 50°. The horizontal push rod 28 contacts the top surface of the receiving rod 25.

[0086] The basic working principle of the pushing mechanism is as follows: When the bell jar 10 needs to be moved downward, the telescopic drive component 21 is activated, pushing the guide rod 27 and the flat push rod 28 downward, thereby pushing the receiving rod 25 downward so that the bell jar 10 moves downward; after the receiving rod 25 is engaged below the bottom surface 32 of the locking position, the first sealing gasket 12 and the second sealing gasket 13 make contact to achieve a seal; after the nitrogen purging is completed, when the first sealing gasket 12 and the second sealing gasket 13 need to be separated again, the telescopic drive component 21 can be used to drive the inclined push rod 29 upward. At this time, under the action of the inclined push rod 29, the receiving rod 25 will gradually move away from below the bottom surface 32 of the locking position. When it is completely moved away, the receiving rod 25 and the bell jar 10 fixed to it will return to the position under the action of the elastic sealing cylinder 11. Figure 3 The state shown indicates that the first sealing gasket 12 and the second sealing gasket 13 are separated.

[0087] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bell-shaped sealing structure for a vertical high-temperature submersible pump, characterized in that, Includes pump shaft (1), isolation cylinder (8), enclosure seat, packing gland assembly (9) and bell jar (10); The pump shaft (1) passes through the isolation cylinder (8) and the packing gland assembly (9) from bottom to top. A fitting clearance is formed between the isolation cylinder (8) and the pump shaft (1); The enclosure seat is fitted on the outside of the isolation cylinder (8), and the two work together to form a receiving cavity (2) for containing the sealing medium molten salt. The packing gland assembly (9) is fixedly connected to the enclosure seat, and the pump shaft (1) is rotatably and sealingly connected to the packing gland assembly (9); The bottom of the bell jar (10) is immersed in the molten salt of the sealing medium so that the receiving cavity (2) forms an outer cavity and an inner cavity. The outer cavity and the inner cavity are connected below the molten salt of the sealing medium and isolated above the molten salt of the sealing medium. The top of the bell jar (10) is located above the liquid surface of the sealing medium molten salt, and an elastic sealing cylinder (11) is provided between it and the packing gland assembly (9). The upper and lower ends of the elastic sealing cylinder (11) are respectively sealed to the packing gland assembly (9) and the bell jar (10), so that the top end of the elastic sealing cylinder (11) is isolated from the external environment through the packing gland assembly (9), and the bottom end of the elastic sealing cylinder (11) is connected to the inner cavity. A second sealing gasket (13) is fixedly installed on the top of the isolation cylinder (8), and the second sealing gasket (13) is located above the liquid surface of the sealing medium molten salt; A first sealing gasket (12) is connected to the bell jar (10); The first sealing gasket (12) and the second sealing gasket (13) are sequentially fitted around the pump shaft (1) from top to bottom, and a connecting gap is formed between them to connect the fitting gap and the inner cavity; The elastic sealing cylinder (11) can elastically elongate along its own axis under the action of the pushing mechanism, so that the first sealing gasket (12) is pressed against the second sealing gasket (13) to cut off the connecting gap.

2. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 1, characterized in that, The elastic sealing cylinder (11) is provided with an elastic connector (14) inside, and the first sealing gasket (12) is connected to the bell jar (10) through the elastic connector (14).

3. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 2, characterized in that, The bottom end of the elastic connector (14) is fixedly connected to the bell jar (10), and the top end is fixedly connected to the connecting cylinder (16) through the connecting cover (15). The first sealing gasket (12) is fixedly connected to the bottom end of the connecting cylinder (16).

4. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 2, characterized in that, The elastic sealing cylinder (11) is a spiral metal bellows.

5. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 4, characterized in that, The packing gland assembly (9) is fixedly installed on the enclosure seat via the first support frame (19); The first support frame (19) has a protrusion (30) fixedly connected to its side. The protrusion (30) includes a guide slope (31) and a locking bottom surface (32). A support rod (25) is fixedly connected to the side of the bell jar (10), and the support rod (25) extends horizontally to the top of the protrusion (30); The pushing mechanism pushes the receiving rod (25) down, causing the elastic sealing cylinder (11) to elastically extend along its own axis. As the receiving rod (25) passes through the guide slope (31), it causes the elastic sealing cylinder (11) to twist at a preset angle. Before the top surface of the receiving rod (25) is flush with the bottom surface of the locking position (32), the first sealing gasket (12) and the second sealing gasket (13) make contact to achieve sealing. When the top surface of the receiving rod (25) is flush with the bottom surface of the locking position (32), the elastic sealing cylinder (11) returns from the twisted state to the non-twisted state under the action of the torsional restoring force, and causes the first sealing gasket (12) and the second sealing gasket (13) to rotate relative to each other.

6. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 5, characterized in that, Before the receiving rod (25) contacts the guide ramp (31), the first sealing gasket (12) and the second sealing gasket (13) make contact to achieve a seal.

7. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 5, characterized in that, The actuation mechanism includes a guide sleeve (26), a guide rod (27), a horizontal push rod (28), an inclined push rod (29), and a telescopic drive component (21). The telescopic drive component (21) is fixedly installed on the top of the first support frame (19); The guide sleeve (26) is fixedly installed on the side of the first support frame (19), and the guide rod (27) slides vertically through the guide sleeve (26), and the top end of the guide rod (27) is connected to the telescopic drive component (21); The flat push rod (28) is fixed to the bottom end of the guide rod (27), and the inclined push rod (29) is fixed to the flat push rod (28) and forms a predetermined angle with the flat push rod (28); The push rod (28) contacts the top surface of the receiving rod (25).

8. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 1, characterized in that, The bottom of the first sealing gasket (12) has a second conical surface (23), and the top surface of the second sealing gasket (13) has a first conical surface (22), and the first conical surface (22) and the second conical surface (23) are matched.

9. The bell-shaped sealing structure for a vertical high-temperature submersible pump according to claim 1, characterized in that, The enclosure includes a support plate (3) and an outer cylinder (4), a heat insulation layer (5), a heating layer (6), and an inner cylinder (7) arranged sequentially from the outside to the inside. The bottoms of the outer cylinder (4), the insulation layer (5), the heating layer (6), and the inner cylinder (7) are fixedly connected to the support plate (3); The bottom end of the isolation cylinder (8) passes through the support plate (3); The receiving cavity (2) is located inside the inner cylinder (7).

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