Shaft end sealing structure suitable for slurry evaporator and slurry evaporator

Abstract

The utility model discloses a shaft end sealing structure suitable for a slurry evaporator and the slurry evaporator, and the shaft end sealing structure comprises a first packing sealing assembly, a depressurization replacement assembly, a second packing sealing assembly, a third sealing assembly and a fourth sealing assembly which are sequentially arranged on a rotating shaft of the slurry evaporator in an abutting mode from inside to outside. The first packing sealing assembly, the pressure reduction replacement assembly, the second packing sealing assembly and the third sealing assembly define a first sealing cavity, a pressure reduction replacement cavity, a second sealing cavity and a third sealing cavity with the outer surface of the slurry evaporator rotating shaft correspondingly, and the first sealing cavity and the second sealing cavity are filled with muddy packing. The depressurization replacement cavity is filled with a purging medium, and the third sealing cavity is filled with a pressure medium. According to the utility model, the leaked gas-phase medium is treated in a centralized manner in a depressurization replacement manner, so that the gas-phase medium is prevented from being directly exposed in the atmosphere, and meanwhile, the amount of gas entering the next section of sealing structure can be reduced, so that the service life of the whole sealing structure is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon production, in particular to a shaft end sealing structure suitable for a slurry evaporator and the slurry evaporator. Background Art

[0002] The main equipment in the cold hydrogenation slurry treatment process in the polysilicon industry is the intermittent rake dryer. Once the material inside the slurry evaporator leaks out, it will harm the human body and there is a risk of combustion and explosion, which will cause serious environmental pollution. Therefore, when the slurry evaporator is in operation, the slurry evaporator needs to be sealed to prevent the material inside the slurry evaporator from leaking. Currently, the sealing structure of the slurry treatment rake dryer in the industry has always been flawed. Due to the special nature of polysilicon high-boiling materials, the traditional method of pressure packing seal plus mechanical seal is used. However, there are common problems such as material leakage and corrosion of the shaft sleeve and bearings. This leads to a shortened service life of the slurry evaporator and frequent and difficult replacement and maintenance.

[0003] Utility model patent publication number CN218454962U discloses a dynamic sealing structure for slurry evaporation. This structure achieves dynamic sealing for the slurry evaporator by combining a packing seal, a gas seal, and a mechanical seal. This sealing structure reduces wear on the rotating shaft and prevents material leakage over time. However, after use, it was found that the sealing structure had a short service life and high maintenance costs. Summary of the Invention

[0004] To address the problems and shortcomings of the aforementioned prior art, the present invention proposes a shaft-end sealing structure and slurry evaporator suitable for a slurry evaporator. This structure forms a multi-stage sealing structure on the slurry evaporator's rotating shaft, combining a two-stage packing seal at the front end, a pressure medium seal in the middle section, and a mechanical seal or packing seal at the end. A pressure-reducing replacement assembly is provided between the two-stage packing seals. This seal extends the service life of the entire structure and reduces wear on the equipment's rotating shaft, preventing material leakage over time. This extends the continuous operating time of the slurry evaporator, saves labor and maintenance costs, avoids the risk of pipeline blockage due to maintenance, and significantly improves system stability.

[0005] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present utility model is as follows:

[0006] On the one hand, the utility model proposes a shaft end sealing structure suitable for a slurry evaporator, the shaft end sealing structure includes a first packing sealing assembly, a pressure reduction replacement assembly, a second packing sealing assembly, a third sealing assembly and a fourth sealing assembly which are sequentially abutted and arranged on the rotating shaft of the slurry evaporator from the inside to the outside, the first packing sealing assembly, the pressure reduction replacement assembly, the second packing sealing assembly and the third sealing assembly are respectively enclosed with the outer surface of the rotating shaft of the slurry evaporator to form a first sealing cavity, a pressure reduction replacement cavity, a second sealing cavity and a third sealing cavity, the first sealing cavity and the second sealing cavity are filled with mud-like fillers, the pressure reduction replacement cavity is filled with a purge medium, and the third sealing cavity is filled with a pressure medium.

[0007] Preferably, the pressure-reducing replacement assembly includes a mounting sleeve sleeved on the slurry evaporator shaft, a pressure-reducing replacement chamber is formed between the inner wall of the mounting sleeve and the outer surface of the slurry evaporator shaft, and a replacement inlet and a replacement outlet are provided on the mounting sleeve.

[0008] Preferably, the first packing seal assembly, the second packing seal assembly and the third seal assembly are respectively provided with a first packing injection port, a second packing injection port and a pressure medium injection port.

[0009] Preferably, the first packing sealing assembly includes a first packing sealing cylinder sleeved on the slurry evaporator shaft, a first sealing cavity is formed between the inner wall of the first packing sealing cylinder and the outer surface of the slurry evaporator shaft, and the first packing sealing cylinder is provided with a first packing injection port.

[0010] Preferably, the second packing sealing assembly includes a second packing sealing tube sleeved on the slurry evaporator shaft, a second sealing cavity is formed between the inner wall of the second packing sealing tube and the outer surface of the slurry evaporator shaft, and the second packing sealing tube is provided with a second packing injection port.

[0011] Preferably, the third sealing assembly includes a third sealing cylinder, a third sealing cavity is formed between the inner wall of the third sealing cylinder and the outer surface of the slurry evaporator shaft, and the third sealing cylinder is provided with a pressure medium injection port.

[0012] Preferably, the fourth sealing assembly is a mechanical sealing assembly, including an end cover mounted on the slurry evaporator shaft, a stationary ring component fixed on the end cover, and a dynamic ring component abutting the stationary ring component, the end cover is connected to the tail of the third sealing assembly, the static ring component includes a static ring and a static ring pressure plate, the static ring pressure plate is connected to the end cover, the static ring is arranged between the end cover and the static ring pressure plate, the dynamic ring component includes a dynamic ring seat, a dynamic ring push plate, a dynamic ring, a spring and a fixed adjusting ring, the dynamic ring seat is arranged on the slurry evaporator shaft, the dynamic ring push plate is mounted on the dynamic ring seat, the spring abuts between the dynamic ring push plate and the dynamic ring seat, the dynamic ring abuts between the dynamic ring push plate and the static ring, the fixed adjusting ring is fixedly connected to the slurry evaporator shaft, a threaded hole is provided on the fixed adjusting ring, an adjusting screw is provided in the threaded hole, and the end of the adjusting screw contacts the dynamic ring seat.

[0013] Preferably, the fourth sealing assembly is a packing sealing assembly, comprising a packing and a packing gland sleeved on the slurry evaporator shaft, the surface of the packing being sleeved with a packing sleeve, one end of the packing gland being connected to the packing sleeve, and the other end being inserted into the gap between the tail of the packing sleeve and the outer surface of the slurry evaporator shaft and pressing against the packing in the packing sleeve.

[0014] Preferably, elastic sealing rings are respectively provided between the first packing sealing assembly, the second packing sealing assembly, the fourth sealing assembly and the outer surface of the slurry evaporator shaft, and the elastic sealing rings are step seals.

[0015] Based on the same inventive concept, the present invention further provides a slurry evaporator on the other hand, which includes the above-mentioned shaft end sealing structure, and the shaft end sealing structure is arranged on the rotating shaft of the slurry evaporator.

[0016] Beneficial effects of the utility model:

[0017] (1) The utility model forms a multi-stage sealing structure on the rotating shaft of the slurry evaporator in sequence by combining the two-stage packing seal at the front end, the pressure medium seal in the middle section, and the mechanical seal or packing seal at the end, and a pressure reduction replacement component is added between the two sections of the packing seal structure. The pressure reduction replacement component purges and replaces the small amount of gaseous medium leaked from the first section of the sealing structure, and the replaced gaseous medium is centrally processed to prevent it from being directly exposed to the atmosphere and polluting the environment. At the same time, the pressure reduction replacement method can greatly reduce the amount of gas entering the next section of the packing seal structure, thereby extending the service life of the next section of the packing seal structure. Therefore, the service life of the entire sealing structure is further extended. Based on the above sealing structure, the utility model greatly extends the service life of the sealing structure and reduces maintenance costs.

[0018] (2) The utility model's combined multi-stage sealing structure of mud filler + pressure reduction replacement + mud filler + air seal + mechanical seal / packing seal effectively improves the mechanical efficiency of the slurry evaporator and reduces the wear on the shaft. In addition, since the packing gland can maintain long-term no leakage, it is more conducive to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The foregoing and following detailed description of the present invention will become more clear when read in conjunction with the following drawings, in which:

[0020] Figure 1 This is a structural diagram of Example 1 of the utility model;

[0021] Figure 2 This is a structural diagram of Example 2 of the present utility model.

[0022] In the picture:

[0023] 1. First packing seal assembly; 2. Second packing seal assembly; 3. Third seal assembly; 4. Mechanical seal assembly; 5. Packing seal assembly; 6. Slurry evaporator shaft; 7. Pressure reduction replacement assembly; 8. Elastic sealing ring; 11. First packing seal cylinder; 21. Second packing seal cylinder; 31. Third seal cylinder; 41. End cover; 42. Stationary ring; 43. Stationary ring pressure plate; 44. Dynamic ring seat; 45. Dynamic ring push plate; 46. Dynamic ring; 47. Spring; 48. Fixed adjustment ring; 49. Adjusting screw; 51. Packing; 52. Packing gland; 53. Packing sleeve; 71. Mounting sleeve; 100. First sealing chamber; 200. Second sealing chamber; 300. Third sealing chamber; 700. Pressure reduction replacement chamber. DETAILED DESCRIPTION

[0024] In order to help those skilled in the art better understand the technical solutions of the present invention, the following will further illustrate the technical solutions for achieving the purpose of the present invention through several specific embodiments. It should be noted that the technical solutions claimed for protection by the present invention include but are not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Example 1

[0026] This embodiment discloses a shaft end sealing structure suitable for a slurry evaporator. Figure 1As shown, the shaft end sealing structure includes a first packing sealing component 1, a second packing sealing component 2, a third sealing component 3 and a fourth sealing component which are sequentially abutted against the slurry evaporator shaft 6 from the inside to the outside along the length direction of the slurry evaporator shaft 6. The first packing sealing component 1, the second packing sealing component 2 and the third sealing component 3 are respectively enclosed with the outer surface of the slurry evaporator shaft 6 to form a first sealing cavity 100, a second sealing cavity 200 and a third sealing cavity 300. The first sealing cavity 100 and the second sealing cavity 200 are filled with mud-like fillers, and the third sealing cavity 300 is filled with pressure medium.

[0027] In the embodiment described in this example, the sludge filler in the first and second sealed cavities is a mixture of carbon fiber, high-purity graphite, polytetrafluoroethylene, and an organic sealant. The sludge filler is heat-resistant from -18°C to 200°C, has a maximum pressure of 0.7 MPa, and a maximum linear speed of 8 m / s. It is highly corrosion-resistant and suitable for media with a pH range of 4-13. Media contact tests have shown that the sludge filler does not react with high-boiling or chlorosilanes. This filler is in a clay-like state, exhibiting a low coefficient of friction and minimal molecular attraction between the mixture. During the operation of the slurry evaporator's shaft, the fibers in the packing will be entangled on the shaft and rotate with the shaft to form a "rotating layer". This "rotating layer" protects the shaft or sleeve, avoids sleeve wear, and reduces power consumption. As the diameter of the "rotating layer" gradually increases, the shaft's ability to entangle the fibers will gradually weaken. The fibers will no longer be entangled with the shaft and will remain relatively stationary with the inner wall of the sealed chamber, forming a "shear layer" in the chamber. At this time, the friction shear area of ​​the relative rotational motion exists in the middle of the packing rather than between the packing and the shaft.

[0028] It should be noted that the mud filler itself does not belong to the invention and innovation of the present invention, but is a prior art, and therefore will not be described in detail.

[0029] In the embodiment described in this example, "from inside to outside" refers to the direction from the slurry evaporator housing to the end of the slurry evaporator shaft. It is understood that the first packing seal assembly 1, the second packing seal assembly 2, the third seal assembly 3, and the fourth seal assembly are all disposed within the bearing seat of the slurry evaporator shaft 6, and the end of the first packing seal assembly 1 is fixedly connected to the slurry evaporator housing via bolts, while the first packing seal assembly 1, the second packing seal assembly 2, the third seal assembly 3, and the fourth seal assembly are connected sequentially at their ends via bolts.

[0030] In the implementation method described in this embodiment, a receiving groove is provided on the casing of the slurry evaporator for accommodating the end of the first packing seal assembly 1. The groove structure better ensures the concentricity requirements between the sealing structure and the evaporator shaft 6, is more conducive to assembly, improves assembly accuracy, and thus better ensures the sealing performance of the dynamic seal.

[0031] In the implementation described in this embodiment, it can be understood that the first packing sealing assembly 1, the second packing sealing assembly 2, the third sealing assembly 3 and the fourth sealing assembly are provided with sealing gaskets at the connection positions of two adjacent sealing assemblies to prevent gas leakage from the connection points of the sealing assemblies.

[0032] For further information, please refer to the appendix of the manual. Figure 1 and Figure 2 As shown, optionally, the first packing sealing assembly 1 includes a first packing sealing cylinder mounted on the slurry evaporator shaft 6, and two first connecting flanges are provided at both ends of the first packing sealing cylinder 11. The circumferential edge of the first connecting flange is provided with an elastic sealing ring 8, and the outer surface of the slurry evaporator shaft 6 contacts the elastic sealing ring 8, and the two form a rotating seal fit; the first connecting flange at the end is fixedly connected to the casing of the slurry evaporator by bolts, and there is a gap between the inner wall of the sealing cylinder and the outer surface of the slurry evaporator shaft 6, and the gap forms a first sealing cavity 100, and the first packing sealing cylinder 11 is also provided with a first packing injection port connected to the first sealing cavity 100.

[0033] Optionally, the second packing seal assembly 2 includes a second packing seal tube 21 sleeved on the slurry evaporator shaft 6. The structure of the second packing seal tube 21 is similar to that of the first packing seal tube 11. Similarly, two second connecting flanges are provided at both ends. The circumferential edges of the connecting flanges are provided with elastic sealing rings 8. The outer surface of the slurry evaporator shaft 6 contacts the elastic sealing ring 8, and the two form a rotating seal. Furthermore, the second connecting flange at the end is connected to the first connecting flange at the tail end of the first packing seal tube by bolts. A gap is provided between the inner wall of the second packing seal tube 21 and the outer surface of the slurry evaporator shaft 6, forming a second sealed cavity 200. The second packing seal tube 21 is provided with a second packing injection port connected to the second sealed cavity 200.

[0034] During operation, the slurry evaporator uses the two aforementioned filler inlets to replenish filler into the two sealed cavities without shutting down the machine, thereby ensuring the overall sealing effectiveness of the sealing structure. Furthermore, an elastic sealing ring 8, mounted on the connecting flange, compensates for the manufacturing gap between the rotating shaft and the sealing cylinder, effectively preventing filler from being squeezed out of the cavity and creating a good internal seal. To enhance the sealing effectiveness of the elastic sealing ring, the ring 8 is a shaft-mounted seal.

[0035] It should be noted that, please refer to the attached manual Figure 2 As shown, in order to simplify the structure, the first packing sealing cylinder 11 and the second packing sealing cylinder 21 can be combined into one sealing cylinder, and connecting flanges are respectively provided at both ends of the sealing cylinder. The two flanges are respectively connected to the casing of the slurry evaporator and the third sealing cylinder 31. A convex ring is provided inside the sealing cylinder, and the convex ring separates the sealing cavity formed between the inner wall of the sealing cylinder and the outer surface of the slurry evaporator shaft 6 into a first sealing cavity 100 and a second sealing cavity 200. An elastic sealing ring is provided on the convex ring, and the outer surface of the slurry evaporator shaft 6 contacts the elastic sealing ring 8, and the two form a rotating seal.

[0036] Optionally, the third sealing assembly 3 includes a third sealing cylinder 31, the two ends of which are respectively connected to the second connecting flange at the tail of the second packing sealing cylinder 21 and the end of the fourth sealing assembly. The gap between the inner wall of the third sealing cylinder 31 and the outer surface of the slurry evaporator shaft 6 forms a third sealing cavity 300, and the third sealing cylinder 31 is provided with a pressure medium injection port connected to the third sealing cavity 300. After the external pressure medium enters the third sealing cavity 300 through the pressure medium injection port, it will squeeze the elastic sealing ring 8. After the elastic sealing ring 8 is compressed, it can seal the gap between the packing sealing cylinder and the slurry evaporator shaft 6. In some embodiments, the pressure medium can be an inert gas such as nitrogen. In addition, through the above-mentioned pressure medium injection port, it is also possible to continuously replenish the pressure medium into the third sealing cavity without stopping the machine, thereby ensuring the overall sealing effect of the sealing structure.

[0037] Due to the material characteristics inside the rake dryer, in order to prevent the material from leaking due to incomplete injection into the packing sealing cavity, which may cause safety hazards such as combustion, an air-sealing structure is added behind the muddy soft packing. The sealing cavity of the air-sealing structure is filled with sealed inert gas. The pressure of the inert gas in the sealing cavity is greater than the pressure in the dryer barrel. Even if a leak occurs, it will be sealed so that the internal material gas cannot leak out and cause safety hazards.

[0038] Example 2

[0039] This embodiment discloses a shaft end sealing structure suitable for a slurry evaporator. Figure 2As shown, on the basis of Example 1, a pressure-reducing replacement assembly 7 for purging leaked gas is further provided between the first packing seal assembly 1 and the second packing seal assembly 2. Specifically, the pressure-reducing replacement assembly 7 includes a mounting sleeve 71 sleeved on the slurry evaporator shaft 6. The mounting sleeve 71 abuts between the first packing seal tube 11 and the second packing seal tube 21, and its two ends are connected to the first connecting flange and the second connecting flange respectively by bolts. A pressure-reducing replacement chamber 700 is formed between the inner wall of the mounting sleeve 71 and the outer surface of the slurry evaporator shaft 6. A replacement inlet and a replacement outlet connected to the pressure-reducing replacement chamber 700 are provided on the mounting sleeve 71. Inert gas such as nitrogen enters the pressure-reducing replacement chamber 700 through the replacement inlet, dilutes the gas leaked from the slurry evaporator shaft 6, and gradually replaces it through the replacement outlet, thereby reducing the concentration of the leaked gas in the chamber and preventing high-concentration leaked gas from gradually flowing to the next-level sealing structure, greatly extending the service life of the entire sealing structure. Compared with the existing sealing structure, the service life of the sealing structure of the utility model is extended by dozens of times, and the maintenance cost is reduced by more than ten times.

[0040] Example 3

[0041] This embodiment discloses a shaft end sealing structure suitable for a slurry evaporator. Figure 1 or Figure 2 As shown, based on the above-mentioned embodiment 1 or embodiment 2, the fourth sealing assembly is a mechanical sealing assembly 4, which includes an end cover 41 sleeved on the slurry evaporator shaft 6, a stationary ring component fixed on the end cover 41, and a dynamic ring component abutting the stationary ring component. The end cover 41 is connected to the tail of the third sealing cylinder 31, and the stationary ring component includes a stationary ring 42 and a stationary ring pressure plate 43. The stationary ring pressure plate 43 is connected to the end cover 41, and the stationary ring 42 is arranged between the end cover 41 and the stationary ring pressure plate 43; the dynamic ring component includes a dynamic ring seat 44 , a moving ring push plate 45, a moving ring 46, a spring 47 and a fixed adjusting ring 48, the moving ring seat 44 is arranged on the slurry evaporator shaft 6, the moving ring push plate 45 is sleeved on the moving ring seat 44, the spring 47 is abutted between the moving ring push plate 45 and the moving ring seat 44, the moving ring 46 is abutted between the moving ring push plate 45 and the static ring 42, the fixed adjusting ring 48 is fixedly connected to the slurry evaporator shaft 6, a threaded hole is provided on the fixed adjusting ring 48, an adjusting screw 49 is provided in the threaded hole, and the end of the adjusting screw 49 is in contact with the moving ring seat 44.

[0042] Example 4

[0043] This embodiment discloses a shaft end sealing structure suitable for a slurry evaporator. Figure 1 or Figure 2As shown, on the basis of the above-mentioned embodiment 1 or embodiment 2, the fourth sealing assembly is a packing sealing assembly 5, which includes a packing 51, a packing gland 52 and a packing sleeve 53. The packing 51 is inserted into the packing cavity of the packing sleeve 53 and then sleeved on the slurry evaporator shaft 6. The packing 51 is located at the end of the packing sleeve 53, and the end of the packing sleeve 53 is fixedly connected to the tail of the third sealing tube 31 by bolts. The packing gland 52 is sleeved on the slurry evaporator shaft 6, one end of which is fixedly connected to the tail of the packing sleeve 53 by bolts, and the other end is inserted into the gap between the tail of the packing sleeve 53 and the outer surface of the slurry evaporator shaft 6 and presses against the packing 51 in the packing sleeve 53, that is, the packing 51 presses between the packing sleeve 53 and the packing end cover 52.

[0044] Example 5

[0045] This embodiment discloses a slurry evaporator, which includes a slurry evaporator rotating shaft 6 . The slurry evaporator rotating shaft 6 is provided with the shaft end sealing structure described in any of the above embodiments.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as limiting the scope of protection of the present invention.

[0047] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention falls within the scope of protection of the present invention.

Claims

1. The shaft end sealing structure is applicable to the slurry evaporator, characterized in that: The shaft end sealing structure comprises a first packing seal assembly (1), a pressure reduction replacement assembly (7), a second packing seal assembly (2), a third seal assembly (3) and a fourth seal assembly which are abutted against and arranged on the slurry evaporator shaft (6) in sequence from the inside to the outside. The first packing seal assembly (1), the pressure reduction replacement assembly (7), the second packing seal assembly (2) and the third seal assembly (3) are respectively enclosed with the outer surface of the slurry evaporator shaft (6) to form a first sealing cavity (100), a pressure reduction replacement cavity (700), a second sealing cavity (200) and a third sealing cavity (300). The first sealing cavity (100) and the second sealing cavity (200) are filled with muddy packing, the pressure reduction replacement cavity (700) is filled with a purge medium, and the third sealing cavity (300) is filled with a pressure medium.

2. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The pressure reduction displacement assembly (7) comprises a mounting sleeve (71) sleeved on the slurry evaporator shaft (6), a pressure reduction displacement chamber (700) being formed between the inner wall of the mounting sleeve (71) and the outer surface of the slurry evaporator shaft (6), and a displacement inlet and a displacement outlet being provided on the mounting sleeve (71).

3. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The first packing seal assembly (1), the second packing seal assembly (2) and the third seal assembly (3) are respectively provided with a first packing injection port, a second packing injection port and a pressure medium injection port.

4. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The first packing seal assembly (1) comprises a first packing seal cylinder (11) sleeved on the slurry evaporator shaft (6), a first sealing cavity (100) being formed between the inner wall of the first packing seal cylinder (11) and the outer surface of the slurry evaporator shaft (6), and the first packing seal cylinder (11) is provided with a first packing injection port.

5. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The second packing seal assembly (2) comprises a second packing seal cylinder (21) sleeved on the slurry evaporator shaft (6), a second sealing cavity (200) being formed between the inner wall of the second packing seal cylinder (21) and the outer surface of the slurry evaporator shaft (6), and a second packing injection port being provided in the second packing seal cylinder (21).

6. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The third sealing assembly (3) comprises a third sealing cylinder (31), a third sealing cavity (300) is formed between the inner wall of the third sealing cylinder (31) and the outer surface of the slurry evaporator shaft (6), and the third sealing cylinder (31) is provided with a pressure medium injection port.

7. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The fourth sealing assembly is a mechanical sealing assembly (4), comprising an end cover (41) sleeved on the rotating shaft (6) of the slurry evaporator, a stationary ring component fixed on the end cover (41), and a dynamic ring component abutting against the stationary ring component, the end cover (41) being connected to the rear end of the third sealing assembly (3), the stationary ring component comprising a stationary ring (42) and a stationary ring pressure plate (43), the stationary ring pressure plate (43) being connected to the end cover (41), the stationary ring (42) being arranged between the end cover (41) and the stationary ring pressure plate (43), the dynamic ring component comprising a dynamic ring seat (44), a dynamic ring push plate (45), a dynamic ring (46), a spring (47), and a plurality of other components. 7) and a fixed adjustment ring (48), the moving ring seat (44) is arranged on the rotating shaft (6) of the slurry evaporator, the moving ring push plate (45) is sleeved on the moving ring seat (44), the spring (47) is abutted between the moving ring push plate (45) and the moving ring seat (44), the moving ring (46) is abutted between the moving ring push plate (45) and the stationary ring (42), the fixed adjustment ring (48) is fixedly connected to the rotating shaft (6) of the slurry evaporator, a threaded hole is arranged on the fixed adjustment ring (48), an adjusting screw (49) is arranged in the threaded hole, and the end of the adjusting screw (49) is in contact with the moving ring seat (44).

8. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: The fourth sealing assembly is a packing sealing assembly (5), comprising a packing (51) and a packing gland (52) sleeved on the slurry evaporator shaft (6); a packing sleeve (53) is sleeved on the surface of the packing (51); one end of the packing gland (52) is connected to the packing sleeve (53); the other end is inserted into a gap between the rear end of the packing sleeve (53) and the outer surface of the slurry evaporator shaft (6) and presses against the packing (51) in the packing sleeve (53).

9. The shaft end sealing structure suitable for a slurry evaporator according to claim 1, characterized in that: Elastic sealing rings (8) are respectively arranged between the first packing sealing assembly (1), the second packing sealing assembly (2), the fourth sealing assembly and the outer surface of the slurry evaporator shaft (6), and the elastic sealing rings (8) are step seals.

10. A slurry evaporator, characterized in that: It comprises the shaft end sealing structure as described in any one of claims 1 to 9, wherein the shaft end sealing structure is arranged on the rotating shaft of the slurry evaporator.

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