Transmission shaft sealing device and equipment for radiochemical equipment

Abstract

The transmission shaft sealing device comprises a static ring, an abutting assembly and a movable ring which are sequentially arranged in the axial direction of a transmission shaft, the static ring is arranged on the periphery of the transmission shaft in a sleeving mode, the inner hole wall of the static ring makes contact with the outer circumferential wall of the transmission shaft to form movable sealing, and the abutting assembly is an elastic cylindrical piece which can stretch out and draw back in the axial direction of the transmission shaft. One end of the movable ring is connected to the static ring, the other end of the movable ring abuts against the end face, facing the static ring, of the movable ring, the movable ring is connected to the transmission shaft in a sleeved mode, and a flow guide mechanism is arranged on the end face, deviating from the static ring, of the movable ring and drives gas to flow in the process that the movable ring synchronously rotates along with the transmission shaft. And an air film covering the outer surface of the gap between the moving ring and the abutting assembly is formed. The sealing device is good in sealing effect, a medium is effectively prevented from passing through a gap, and the service life is long. The invention further provides radioactive chemical material treatment equipment.

Description

Technical Field

[0001] This invention specifically relates to a transmission shaft sealing device and equipment for radiochemical equipment. Background Technology

[0002] Currently, most chemical operations in radiochemical (i.e., radioactive chemical) plants are carried out under high-radioactive conditions. Due to the extremely high levels of radioactivity, it is necessary to effectively shield radioactive materials while meeting the requirements of the operational procedures. Therefore, the processing equipment is usually located in a shielded area, for example, designed as a structure that penetrates through the floor slab to provide radiation protection through the floor slab.

[0003] In rotating machinery, the rotating shaft (drive shaft) plays a crucial role in transmitting power and motion. However, the gap between the rotating shaft and the internal cavity of the processing equipment is highly susceptible to media leakage. When used to process radioactive materials, this not only wastes resources and pollutes the environment but can also cause equipment malfunctions and endanger production safety. Given this leakage hazard, and to facilitate maintenance and replacement of the transmission system, the power component of the transmission system must be located outside the radioactive shielding area where the processing equipment is situated. A shielding block, acting as the wall of the shielding area, separates the radioactive area from the transmission system. The drive shaft then passes through the shielding block and connects to relevant components of the processing equipment. Therefore, to prevent the leakage of radioactive aerosols and ensure the safety of the external environment, high requirements are placed on the through-wall sealing of the transmission system's shaft system. However, the drive shaft, as the power input point of the processing equipment, rotates at high speed during operation, making it impossible to achieve a static contact seal with its adjacent parts. This easily leads to the leakage of radioactive materials through gaps at these points.

[0004] Among commonly used sealing structures, packing seals, while simple in structure, wear out quickly, have a short lifespan, and require frequent packing replacements. Mechanical seals, while offering excellent sealing performance, are complex in structure, require high installation precision, are difficult to maintain, and are very expensive. Some labyrinth seals and other materials are not resistant to aging in radioactive environments, resulting in a short service life. Furthermore, they can only provide a seal when the equipment is running, leaving a risk of leakage when the equipment is shut down. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the aforementioned shortcomings in the prior art by providing a transmission shaft sealing device for radiochemical equipment. This device has good sealing performance, effectively prevents the medium from passing through the gap, and has a long service life. This invention also provides a radioactive chemical material processing device.

[0006] This invention provides a transmission shaft sealing device for radiochemical equipment, which is connected to a shielding block in the shielding area of ​​the radiochemical equipment and is used to seal the gap where the transmission shaft passes through the shielding block. It includes a stationary ring, an abutment component, and a rotating ring arranged sequentially along the axial direction of the transmission shaft. The stationary ring is sleeved on the outer periphery of the transmission shaft, and the inner wall of the stationary ring contacts the outer peripheral wall of the transmission shaft to form a dynamic seal. The abutment component is an elastic cylindrical component that can extend and retract along the axial direction of the transmission shaft. One end is connected to the stationary ring, and the other end abuts against the end face of the rotating ring facing the stationary ring. The rotating ring is sleeved on the transmission shaft, and a flow guiding mechanism is provided on the end face of the rotating ring away from the stationary ring. The flow guiding mechanism drives the gas flow during the synchronous rotation of the rotating ring with the transmission shaft to form a gas film covering the outer surface of the gap between the rotating ring and the abutment component.

[0007] Furthermore, the end face of the moving ring that is away from the stationary ring is radially outward relative to the radially inward guide surface of the stationary ring, so that the drop of the guide surface along the axial direction of the transmission shaft acts as a guide mechanism to drive the gas flow.

[0008] Furthermore, the end face of the moving ring away from the stationary ring is provided with grooves. The direction of the grooves is arranged with a set deflection angle relative to the radial direction of the moving ring. Multiple grooves are provided, and each groove is evenly distributed around the drive shaft axially, so that the grooves combined with the guide surface serve as a guide mechanism to drive the gas flow.

[0009] Furthermore, the inner wall of the stationary ring and the outer peripheral wall of the drive shaft are in mating contact through a labyrinth seal joint. The stationary ring is provided with an air hole, one end of which extends into the labyrinth seal joint, and the other end is used to communicate with an external air supply device so that the pressure inside the labyrinth seal joint is maintained at a set pressure by supplying air into the labyrinth seal joint. The set pressure is higher than the pressure in the shielded area.

[0010] Furthermore, the abutment assembly includes a bellows and an abutment ring. The bellows is an elastic cylindrical member capable of stretching and contracting along the drive shaft axially. One end of the bellows is connected to the stationary ring, and the other end is connected to the abutment ring, so that under elastic action, the abutment ring abuts against the end face of the moving ring facing the stationary ring.

[0011] Furthermore, the transmission shaft sealing device for radiochemical equipment also includes a connecting seat, which has a sleeve-shaped structure and is sleeved on the outer periphery of the transmission shaft. The outer peripheral wall of the connecting seat is detachably connected to the shielding block. An annular gap is provided between the inner wall and the transmission shaft. The stationary ring, the abutment component, and the moving ring are all disposed within the annular gap. The stationary ring is fixedly connected to the connecting seat.

[0012] Furthermore, the connecting seat is provided with a gasket and a pressure ring. The gasket is connected to the surface of the connecting seat away from the shielding area. The pressure ring is embedded in the inner wall of the connecting seat and is fitted with a gap on the outer periphery of the abutment component and the moving ring, with its two ends abutting the gasket and the stationary ring respectively.

[0013] Furthermore, a positioning groove is provided axially on the inner wall of the connecting seat, the positioning groove passes through one end of the connecting seat away from the shielding area, and a pin is provided on the stationary ring, the pin being embedded in the positioning groove to achieve circumferential positioning of the stationary ring.

[0014] Furthermore, the connecting seat has a radially inwardly folded baffle at one end facing the shielding area, and a groove is formed on the surface of the baffle away from the shielding area. The surface of the stationary ring facing the shielding area has a protrusion, which is embedded in the groove.

[0015] Furthermore, the transmission shaft sealing device for radiochemical equipment also includes a connecting flange, which is connected to the surface of the shielding block facing the shielding area. The connecting seat has a radially outwardly folded positioning part at one end away from the shielding area. The positioning part of the connecting seat is detachably connected to the surface of the shielding block facing out of the shielding area. The connecting seat itself passes through the shielding block and is detachably connected to the connecting flange.

[0016] The present invention also provides a radioactive chemical material processing device, comprising a device body, a power unit, a drive shaft, and the aforementioned drive shaft sealing device for radioactive chemical equipment. The device body is located within a shielded area and is used to process radioactive materials. The power unit is located outside the shielded area and is connected to the device body via the drive shaft that penetrates the shielding block of the shielded area, and is used to provide power to the device body. The drive shaft sealing device for radioactive chemical equipment is connected to the shielding block and is used to seal the gap where the drive shaft penetrates the shielding block.

[0017] The transmission shaft sealing device for radiochemical equipment of the present invention employs a dynamic seal formed by a stationary ring and the outer peripheral wall of the transmission shaft, first constructing a basic sealing barrier to initially prevent radioactive materials from leaking through gaps. The flow guiding mechanism on the rotating ring, rotating synchronously with the transmission shaft, drives airflow to form an air film. This film not only fills the gap between the rotating ring and adjacent stationary components, preventing the leakage of radioactive aerosols, but also significantly reduces direct friction on the sealing surface due to the non-contact nature of the air film, thus significantly extending the lifespan of the sealing device. Simultaneously, its structural complexity is far lower than that of mechanical seals, reducing installation and subsequent maintenance costs, and balancing sealing reliability and practicality. Furthermore, the axial expansion and contraction capability of the contact component ensures that it always fits tightly against the relevant sealing surfaces of the rotating ring, achieving a seal between the stationary and rotating rings. This elastic contact offsets vibrations of the transmission shaft, thermal expansion and contraction, or assembly deviations during equipment operation, preventing media leakage from gaps caused by vibration after shutdown. Therefore, the device can achieve effective sealing whether the equipment is running or stopped. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention;

[0019] Figure 2 This is a cross-sectional schematic diagram of the moving ring of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention;

[0020] Figure 3 This is a top view schematic diagram of the moving ring of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram showing the connection between the stationary ring and the abutment assembly of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention;

[0022] Figure 5 This is a cross-sectional schematic diagram of the stationary ring of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention;

[0023] Figure 6 This is a top view schematic diagram of the stationary ring of the transmission shaft sealing device for radiochemical equipment in Embodiment 1 of the present invention.

[0024] In the diagram: 1. Stationary ring; 11. Labyrinth seal joint; 12. Vent; 13. Raised strip; 14. Graphite ring; 2. Abutment assembly; 21. Bellows; 22. Abutment ring; 3. Moving ring; 31. Groove; 4. Drive shaft; 5. Shielding block; 6. Connecting seat; 61. Gasket; 62. Pressure ring; 63. Positioning groove; 64. Side flange; 641. Groove; 65. Positioning part; 66. Through hole; 7. Pin; 8. Connecting flange; 81. O-ring; 9. Fastener. Detailed Implementation

[0025] The technical solutions of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without creative effort are within the scope of the invention.

[0026] In the description of this invention, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience and simplification of 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. Therefore, they should not be construed as limitations on this invention.

[0027] In the description of this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Example 1

[0030] like Figure 1 and Figure 4 As shown, the transmission shaft sealing device for radiochemical equipment in this embodiment can be used in the field of radiochemical equipment transmission technology. It can be said to provide a more reasonable, feasible, safer and more convenient hybrid sealing structure for transmission shafts. The sealing device is connected to the shielding block 5 in the shielding area where the radiochemical equipment is located, and is used to seal the gap where the drive shaft 4 passes through the shielding block 5. It includes a stationary ring 1, an abutment component 2, and a rotating ring 3 arranged sequentially along the axial direction of the drive shaft 4. The stationary ring 1 is fitted around the outer circumference of the drive shaft 4, and the inner wall of the stationary ring 1 contacts the outer circumferential wall of the drive shaft 4 to form a dynamic seal. The abutment component 2 is an elastic cylindrical component capable of extending and retracting along the axial direction of the drive shaft 4. One end is connected to the stationary ring 1, and the other end abuts against the end face of the rotating ring 3 facing the stationary ring 1. The rotating ring 3 is fitted onto the drive shaft 4. The rotating ring 3 has a flow guiding mechanism on its end face away from the stationary ring 1. During the synchronous rotation of the rotating ring 3 with the drive shaft 4, the flow guiding mechanism drives the gas flow, forming a (flowing) gas film (which can also be called the sealing end face of the rotating ring 3) covering the outer surface, outer periphery, or outer surface of the gap between the rotating ring 3 and the abutment component 2. The airflow direction is as follows: Figure 1 The direction is indicated by the middle arrow. This embodiment is attached. Figure 1 The text only indicates the location of shielding block 5; its specific structure can be set according to the wall conditions of the shielding area.

[0031] The transmission shaft sealing device for radiochemical equipment in this embodiment employs a dynamic seal formed by the stationary ring 1 and the outer peripheral wall of the transmission shaft 4, initially constructing a basic sealing barrier to prevent radioactive material leakage through gaps. The flow guiding mechanism on the rotating ring 3, rotating synchronously with the transmission shaft, drives airflow to form an air film. This film fills the gap between the rotating ring 3 and adjacent stationary components, preventing the leakage of radioactive aerosols. Furthermore, the non-contact nature of the air film significantly reduces direct friction on the sealing surfaces, substantially extending the lifespan of the sealing device. Simultaneously, its structural complexity is far lower than that of mechanical seals, reducing installation and subsequent maintenance costs, thus balancing sealing reliability and practicality. In addition, the axial expansion and contraction capability of the abutment component 2 ensures it always tightly fits the relevant sealing surfaces of the rotating ring 3, achieving a seal between the stationary ring 1 and the rotating ring 3. This elastic abutment counteracts vibrations, thermal expansion and contraction, or assembly deviations caused by the transmission shaft 4 during equipment operation, preventing media leakage from gaps caused by vibration after shutdown. This ensures effective sealing whether the equipment is running or stopped.

[0032] In this embodiment, as Figure 2 and Figure 3 As shown, the end face of the moving ring 3 facing away from the stationary ring 1 is radially outward relative to the radially inward guide surface closer to the stationary ring 1, so that the height difference of the guide surface along the axial direction of the drive shaft 4 acts as a guide mechanism to drive the gas flow. That is, the viscous force of the gas molecules on the surface of the guide surface causes the gas molecules in this layer to rotate synchronously with the moving ring 3. Combined with the axial height difference of the guide surface itself, directional gas flow can be achieved. Specifically, when the moving ring 3 rotates at high speed with the drive shaft 4, the radial height difference of the guide surface guides and pushes the surrounding gas, causing the gas to flow naturally towards the sealing end face of the moving ring, forming a stable gas film. This design forms a directional sealing gas film through a simple structure combined with the operation of the transmission components. The gas film is generated along with the movement, realizing a sealing "structure" accompanying the movement process, further improving sealing reliability and effectively blocking the leakage path of radioactive materials. In this embodiment, this guide surface with axial height difference can be a continuous or discontinuous slope, curved surface, stepped surface, or various combinations thereof.

[0033] In this embodiment, the end face of the rotating ring 3 facing away from the stationary ring 1 is provided with grooves 31. The grooves 31 are arranged with a set deflection angle relative to the radial direction of the rotating ring 3, and there are multiple grooves 31. Each groove 31 is evenly distributed axially around the drive shaft 4 so that the grooves 31, together with the guide surface, act as a guide mechanism to drive the gas flow. That is, through synergistic effect, the stability and sealing performance of the gas film are greatly enhanced. The set deflection angle of the grooves 31 relative to the radial direction of the rotating ring 3 allows the grooves 31 to produce a pumping effect on the gas when the rotating ring 3 rotates. After the gas enters the grooves 31, it is pushed by the inclined groove wall to form a directional flow. Combined with the axial drop of the guide surface, the gas is doubly driven to converge towards the sealing end face of the rotating ring. Compared with a single guide surface, the gas film formation speed is faster and the pressure is more stable. The multiple grooves 31 evenly distributed around the drive shaft 4 can ensure that the gas is evenly distributed on the end face of the rotating ring 3, avoiding gas film breakage caused by poor local gas flow, achieving full coverage of the sealing end face, and completely blocking the leakage path. In this embodiment, the groove 31 can be an arc-shaped groove, oblique groove, spiral groove, or other structure opened on the flow guide surface of the moving ring 3, or it can be a groove-shaped structure formed by a protruding ridge set on the flow guide surface of the moving ring 3.

[0034] In this embodiment, the drive shaft 4 has a stepped shaft structure. The stationary ring 1 is fitted around the outer circumference of the large-diameter shaft section of the drive shaft 4, and the rotating ring 3 is fitted around and connected to the small-diameter shaft section of the drive shaft 4, abutting against the step between the large-diameter and small-diameter shaft sections. The stepped structure of the drive shaft 4 itself provides a natural and precise axial positioning for the key sealing element. The design of the rotating ring 3 abutting against the shaft shoulder fundamentally prevents axial movement during operation, thereby ensuring the stability of the dynamic sealing gap.

[0035] In this embodiment, as Figure 5 As shown, the inner wall of the stationary ring 1 and the outer peripheral wall of the drive shaft 4 form a mating contact through a labyrinth seal joint 11. The stationary ring 1 has an air hole 12, one end of which extends into the labyrinth seal joint 11, and the other end is used to connect with an external air supply device. By supplying air to the labyrinth seal joint 11, the pressure inside the labyrinth seal joint 11 is maintained at a set pressure, which is higher than the pressure within the shielded area. Maintaining a positive pressure relative to the shielded area within the labyrinth seal joint 11 prevents the medium within the shielded area from passing through it. The air supply creates an air curtain effect, generating positive pressure within the labyrinth seal joint 11 to counteract the leakage force of the medium. Therefore, the medium inside and outside the shielded area cannot communicate, preventing leakage within the shielded area. Furthermore, the non-contact structure experiences minimal wear and has a longer service life compared to contact seals. This design also has adaptability to operating conditions, allowing for flexible adjustment of the air supply pressure according to pressure changes within the shielded area, ensuring stable sealing performance.

[0036] In this embodiment, grooves are uniformly distributed along the axial direction on the inner wall of the stationary ring 1. Alternatively, a conventional labyrinth seal surface can be used to form a labyrinth seal structure after contacting the drive shaft 4.

[0037] In this embodiment, the abutment component 2 includes a bellows 21 and an abutment ring 22. The bellows 21 is an elastic cylindrical component capable of axial expansion and contraction along the drive shaft 4. One end of the bellows 21 is connected to the stationary ring 1, and the other end is connected to the abutment ring 22. The abutment ring 22 can be connected by an inlay method, hence it can also be called an inlay ring. Under elastic action, the abutment ring 22 abuts against the end face of the moving ring 3 facing the stationary ring 1. The elastic cylindrical structure of the bellows 21 has excellent axial expansion and contraction capabilities. Even when the drive shaft 4 experiences axial displacement due to vibration or temperature changes, or when there are slight assembly deviations, the abutment ring 22 is pushed by its own elastic force to always tightly abut against the end face of the moving ring 3. Furthermore, as a closed cylinder, it ensures a tight seal and prevents leakage. The abutment ring 22 increases the contact area with the moving ring 3, allowing the abutment pressure to be evenly distributed on the end face of the moving ring 3, preventing excessive local stress from causing deformation of the moving ring 3 or wear of the sealing surface, thus extending the service life of the moving ring 3.

[0038] In this embodiment, the transmission shaft sealing device for radiochemical equipment also includes a connecting seat 6. The connecting seat 6 has a sleeve-like structure and is fitted around the outer periphery of the transmission shaft 4. The outer peripheral wall of the connecting seat 6 is detachably connected to the shielding block 5. An annular gap is provided between the inner wall and the transmission shaft 4. The stationary ring 1, the abutment component 2, and the rotating ring 3 are all disposed within the annular gap. The stationary ring 1 is fixedly connected to the connecting seat 6. This structure allows the connecting seat 6, the stationary ring 1, the abutment component 2, and the rotating ring 3 to form a complete and independent functional unit that can be disassembled and installed as a whole. While achieving sealing under high-speed rotation of the transmission shaft 4, maintenance only requires disassembly of this unit, making maintenance convenient and easy to disassemble. It also greatly simplifies the on-site installation and maintenance process in a radioactive environment, reduces installation errors, significantly shortens the exposure time of maintenance personnel in hazardous environments, and improves operational safety and efficiency.

[0039] In this embodiment, the connecting seat 6 is provided with a gasket 61 and a pressure ring 62. The gasket 61 is connected to the surface of the connecting seat 6 away from the shielding area, and the pressure ring 62 is embedded in the inner wall of the connecting seat 6 and is fitted with a gap around the outer periphery of the abutment component 2 and the moving ring 3, with its two ends abutting against the gasket 61 and the stationary ring 1, respectively. The pressure ring 62 uses the gasket 61 on the connecting seat 6 as a connection reference, and the downward pressure applied by it can firmly fix the stationary ring 1 in the annular gap, preventing the stationary ring 1 from being displaced due to vibration and impact during equipment operation. This structural design allows for more precise positioning and tighter connection of each sealing component, reducing the risk of seal failure caused by component displacement. The gasket 61 has a one-piece annular structure and is connected to the surface of the connecting seat 6 facing the outer side of the shielding area, and can be embedded in the countersunk hole on this surface.

[0040] In this embodiment, a graphite ring 14 is provided at the contact surface between the stationary ring 1 and the connecting seat 6, and a graphite ring 14 is provided at the contact surface between the pressure ring 62 and the stationary ring 1, so as to achieve further gap sealing.

[0041] In this embodiment, a positioning groove 63 is provided axially on the inner wall of the connecting seat 6. The positioning groove 63 penetrates the end of the connecting seat 6 away from the shielding area. A pin 7 is provided on the stationary ring 1, and the pin 7 is embedded in the positioning groove 63 to achieve circumferential positioning of the stationary ring 1. Through a simple pin-groove mating structure, the circumferential positioning problem of the stationary sealing element is cleverly solved. This structure can effectively resist vibration interference, prevent the stationary ring 1 from rotating, and ensure that its internal precision sealing joint always maintains the best fit with the shaft, thereby maintaining the optimal and stable sealing performance.

[0042] In this embodiment, the connecting seat 6 also has a through hole 66 extending from the outer peripheral wall to the inner hole wall. The specific location corresponds to the position of the air hole 12 on the stationary ring 1 after the pin 7 is embedded in the positioning groove 63. This is used to connect an external air supply device to supply air to the labyrinth seal joint 11 through the air hole 12. The through hole 66 and the air hole 12 together form a backflush air inlet for air supply. In this embodiment, as... Figure 6 As shown, a concave annular groove can be provided on the stationary ring 1 at the position corresponding to the air hole 12. Multiple air holes 12 can be provided and evenly distributed along the circumference, so that the compressed air drawn from the through hole 66 can be evenly supplied to all positions around the labyrinth sealing joint 11.

[0043] In this embodiment, the connecting seat 6 has a radially inwardly folded-in flange 64 at the end facing the shielding area. A groove 641 is formed on the surface of the flange 64 facing away from the shielding area. A protrusion 13 is formed on the surface of the stationary ring 1 facing the shielding area, and the protrusion 13 is embedded in the groove 641. The fitting design of the groove 641 and the protrusion 13 achieves precise axial and radial dual positioning of the critical sealing ring. This not only enhances the overall structural rigidity and prevents component displacement, but the tight fit itself may also form an additional static sealing surface, further reducing the risk of leakage from the assembly joint surface.

[0044] In this embodiment, the transmission shaft sealing device for radiochemical equipment also includes a connecting flange 8, which is connected to the surface of the shielding block 5 facing the shielding area. A connecting seat 6 has a radially outwardly folded positioning part 65 at its end away from the shielding area. The positioning part 65 of the connecting seat 6 is detachably connected to the surface of the shielding block 5 facing outward from the shielding area. The connecting seat 6 itself penetrates the shielding block 5 and is detachably connected to the connecting flange 8. Specifically, the connecting seat 6 is connected to the connecting flange 8 through the outer surface of the flange 64. The contact surface is sealed by an O-ring 81 and fastened with an internal hexagonal screw fastener 9. The connecting flange 8 and the positioning part 65 are equivalent to clamping and connecting from both sides of the shielding wall (i.e., the shielding block 5), providing extremely high connection stability. This design allows the sealing module to withstand greater axial force and vibration, ensuring operational stability under complex working conditions. At the same time, the split structure still facilitates quick assembly and disassembly of the part located outside the shielding wall as a whole, greatly simplifying later maintenance.

[0045] In general, this embodiment provides a sealing structure for a drive shaft in a chemical treatment device, improving safety during operation and maintenance through the sealing structure. The device includes a moving ring 3, a gasket 61 (also referred to as the bearing gasket of the drive shaft 4), a pressure ring 62, a graphite ring 14, a pin 7, a stationary ring 1, a connecting seat 6, a connecting flange 8, an O-ring 81, a hexagon socket head cap screw fastener 9, a backflush port, an abutment ring 22, and a bellows 21. The stationary ring 1 and the abutment assembly 2 can also be collectively referred to as the stationary ring assembly, where the stationary ring 1 serves as the sealing base within the stationary ring assembly.

[0046] The connecting seat 6 is connected to the connecting flange 8 by internal hexagonal screws, and an O-ring 81 is provided on the contact surface between the connecting seat 6 and the connecting flange 8. The connecting flange 8 is installed and fixed to the shielding block 5 and other equipment components through bolt holes. Sealing material can be provided on the contact surface between the stationary ring 1 and the connecting seat 6, and between the stationary ring 1 and the pressure ring 62.

[0047] This sealing device can be installed on a horizontal shielding wall such as a floor slab. Below the shielding wall is a shielding room. A moving ring 3 is installed on the stationary ring 1. The upper surface of the moving ring 3 is provided with geometric structures such as spiral grooves, steps, and inclined surfaces. By utilizing fluid dynamic pressure or countercurrent pumping effect, an air film with a certain thickness and rigidity is formed on the sealing end face.

[0048] This embodiment combines the rotating ring 3 and the stationary ring 1 to achieve sealing under high-speed rotation of the drive shaft. Maintenance is convenient, requiring only the disassembly of the stationary ring assembly and its connected components. Furthermore, the bellows 21 expands and contracts to compress the sealing material, sealing the gap between the rotating and stationary ring assemblies. Sealing is automatically achieved through the sealing structure as the drive shaft starts and stops. Taking advantage of the low operating pressure, this embodiment introduces an air-blowing auxiliary scheme based on the labyrinth seal. Back-blowing air enters the labyrinth seal ring and flows in both vertical and horizontal directions, creating an air curtain effect that generates positive pressure within the labyrinth channel. This counteracts the leakage force of the medium, further reducing leakage and thus achieving a seal between the drive shaft and the labyrinth seal ring.

[0049] Example 2

[0050] The radioactive chemical material processing equipment of this embodiment includes a main body, a power unit, a drive shaft 4, and a drive shaft sealing device for radiochemical equipment as described in Embodiment 1. The main body is located within the shielded area and is used to process radioactive materials. The power unit is located outside the shielded area and is connected to the main body via the drive shaft 4 that penetrates the shielding block 5 of the shielded area, and is used to provide power to the main body. The drive shaft sealing device for radiochemical equipment is connected to the shielding block 5 and is used to seal the gap where the drive shaft 4 penetrates the shielding block 5.

[0051] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A sealing device for a transmission shaft in a chemical processing equipment, characterized in that: A shielding block (5) connected to the shielding area where the radiochemical equipment is located is used to seal the gap where the drive shaft (4) passes through the shielding block (5); it includes a stationary ring (1), an abutment assembly (2), and a moving ring (3) arranged sequentially along the axial direction of the drive shaft (4). The stationary ring (1) is sleeved on the outer circumference of the drive shaft (4), and the inner wall of the stationary ring (1) contacts the outer circumferential wall of the drive shaft (4) to form a dynamic seal. The abutment component (2) is an elastic cylindrical member capable of axial extension and retraction along the transmission shaft (4), with one end connected to the stationary ring (1) and the other end abutting against the end face of the moving ring (3) facing the stationary ring (1). The moving ring (3) is sleeved and connected to the transmission shaft (4). The moving ring (3) has a flow guiding mechanism on the end face away from the stationary ring (1). The flow guiding mechanism drives the gas flow during the synchronous rotation of the moving ring (3) with the transmission shaft (4) to form an air film covering the outer surface of the gap between the moving ring (3) and the contact component (2).

2. The transmission shaft sealing device for radiochemical equipment according to claim 1, characterized in that: The end face of the moving ring (3) facing away from the stationary ring (1) is radially outward relative to the radially inward side of the guide surface of the stationary ring (1), so that the drop of the guide surface along the axial direction of the transmission shaft (4) serves as a guide mechanism to drive the gas flow.

3. The transmission shaft sealing device for radiochemical equipment according to claim 2, characterized in that: The moving ring (3) has a groove (31) on its end face away from the stationary ring (1). The grooves (31) are arranged with a set deflection angle relative to the radial direction of the moving ring (3), and there are multiple grooves (31). Each groove (31) is evenly distributed around the drive shaft (4) axially so that the grooves (31) combined with the guide surface can act as a guide mechanism to drive the gas flow.

4. The transmission shaft sealing device for radiochemical equipment according to claim 1, characterized in that: The inner wall of the stationary ring (1) and the outer peripheral wall of the drive shaft (4) form a mating contact through a labyrinth seal joint (11). The stationary ring (1) is provided with an air hole (12). One end of the air hole (12) extends into the labyrinth sealing joint (11), and the other end is used to communicate with an external air supply device so that the pressure inside the labyrinth sealing joint (11) is maintained at a set pressure by supplying air into the labyrinth sealing joint (11). The set pressure is higher than the pressure in the shielding area.

5. The transmission shaft sealing device for radiochemical equipment according to claim 1, characterized in that: The abutment assembly (2) includes a bellows (21) and an abutment ring (22). The bellows (21) is an elastic cylindrical part that can extend and retract axially along the drive shaft (4). One end of the bellows (21) is connected to the stationary ring (1), and the other end is connected to the abutment ring (22) so that under the elastic action, the abutment ring (22) abuts against the end face of the moving ring (3) facing the stationary ring (1).

6. The transmission shaft sealing device for radiochemical equipment according to any one of claims 1 to 5, characterized in that: It also includes a connecting seat (6), which has a sleeve-like structure and is sleeved on the outer periphery of the drive shaft (4). The outer peripheral wall of the connecting seat (6) is detachably connected to the shielding block (5), and an annular gap is provided between the inner wall and the drive shaft (4). The stationary ring (1), the abutment component (2), and the moving ring (3) are all disposed within the annular gap, and the stationary ring (1) is fixedly connected to the connecting seat (6).

7. The transmission shaft sealing device for radiochemical equipment according to claim 6, characterized in that: The connecting seat (6) is provided with a gasket (61) and a pressure ring (62). The gasket (61) is connected to the surface of the connector (6) away from the shielding area. The pressure ring (62) is embedded in the inner wall of the connecting seat (6) and is fitted with a gap on the outer periphery of the abutment component (2) and the moving ring (3), with its two ends abutting against the gasket (61) and the stationary ring (1) respectively.

8. The transmission shaft sealing device for radiochemical equipment according to claim 6, characterized in that: A positioning groove (63) is provided axially on the inner wall of the connecting seat (6), and the positioning groove (63) passes through the end of the connecting seat (6) away from the shielding area. The stationary ring (1) is provided with a pin (7), which is embedded in the positioning groove (63) to achieve circumferential positioning of the stationary ring (1).

9. The transmission shaft sealing device for radiochemical equipment according to claim 6, characterized in that: The connecting seat (6) has a radially inwardly folded baffle (64) at one end facing the shielding area. The baffle (64) has a groove (641) on the surface facing away from the shielding area. The static ring (1) has a raised strip (13) on one end surface facing the shielding area, and the raised strip (13) is embedded in the groove (641).

10. The transmission shaft sealing device for radiochemical equipment according to claim 6, characterized in that: It also includes a connecting flange (8), which is connected to the surface of the shielding block (5) facing the shielding area. The connecting seat (6) has a radially outwardly folded positioning part (65) at one end away from the shielding area. The positioning part (65) of the connecting seat (6) is detachably connected to the surface of the shielding block (5) facing outward from the shielding area. The connecting seat (6) itself passes through the shielding block (5) and is detachably connected to the connecting flange (8).

11. A radioactive chemical material processing device, characterized in that: Includes the equipment body, power unit, drive shaft (4), and drive shaft sealing device for radiochemical equipment as described in any one of claims 1 to 10. The device body is located within the shielded area and is used to process radioactive materials; The power unit is located outside the shielded area and is connected to the equipment body through the drive shaft (4) that passes through the shielded block (5) of the shielded area, and is used to provide power to the equipment body; The transmission shaft sealing device of the radiochemical equipment is connected to the shielding block (5) to seal the gap where the transmission shaft (4) passes through the shielding block (5).

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