Radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function

Abstract

The utility model discloses a kind of radioactive waste cement solidification stirring mechanisms with ultrasonic self-cleaning function, including stirring paddle and the stirring drive transmission assembly of driving stirring paddle stirring, stirring paddle includes paddle shaft and the paddle blade of being fixed on paddle shaft, the upper end of paddle shaft is rigidly connected with vibration transmission shaft, paddle shaft and vibration transmission shaft are all solid shaft;Vibration transmission shaft is transmission connection with the output end of stirring drive transmission assembly and its upper end portion is fixed with ultrasonic transducer, ultrasonic transducer is realized in rotating state under the continuous power supply of slip ring component, the high-frequency vibration of ultrasonic transducer is transmitted to the paddle shaft and paddle blade of stirring paddle by vibration transmission shaft, and the self-cleaning of stirring paddle is realized by cavitation effect generated by ultrasonic vibration;The stirring mechanism provided by the utility model can not only realize the global efficient self-cleaning of stirring paddle, but also greatly reduce processing difficulty and failure rate by optimizing paddle shaft to solid structure, improve overall rigidity and service life of equipment.

Description

Technical Field

[0001] This utility model relates to the field of radioactive waste treatment, specifically to a radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function. Background Technology

[0002] The safe disposal of radioactive waste is a crucial aspect of the nuclear industry. Cement solidification is widely used for treating low- and intermediate-level radioactive waste due to its mature technology, low cost, and good long-term stability. In this process, the mixing mechanism is one of the core pieces of equipment, its function being to thoroughly and uniformly mix the radioactive waste with the cementitious substrate, ensuring the homogeneity and containment of the solidified body.

[0003] Currently, radioactive waste cement solidification mixing mechanisms generally employ a combination of mechanical transmission and mechanical vibration to achieve the self-cleaning function of the mixing blades. A typical approach involves placing an eccentric block on the mixing shaft, which is driven to rotate at high speed to generate mechanical vibration. This vibration is transmitted to the mixing blades, aiming to use the vibration to peel away cement slurry and radioactive contaminants adhering to the blades and shaft, reducing residue.

[0004] However, this mechanical vibration self-cleaning scheme based on eccentric block rotation has obvious limitations:

[0005] 1. Uneven distribution of vibration energy and poor root cleaning effect: The vibration is mainly generated by the high-speed rotation of the eccentric block, and its energy is mainly concentrated in the area near the eccentric block (such as the lower middle or end of the impeller). As the vibration is transmitted to the root of the impeller (i.e., near the drive end), the energy will significantly decrease. This results in weak vibration amplitude in the root area of ​​the impeller, which cannot effectively achieve the self-cleaning function, becoming a key area for radioactive contaminant residue and posing a risk of radioactive spread.

[0006] 2. Complex structure, difficult processing and maintenance: In order to transmit the vibration generated by the eccentric block to the entire stirring shaft, existing solutions usually require the stirring shaft to be designed as a complex hollow structure so that a transmission component can be installed inside the shaft to drive the eccentric block. This hollow shaft design not only increases the difficulty of processing and manufacturing (especially precision welding processes), but also reduces the stiffness and strength of the shaft, and increases maintenance costs and failure risks.

[0007] 3. Requires an additional drive source, resulting in high cost: Driving the eccentric block to rotate typically requires an additional vibration motor or transmission mechanism. This not only increases the overall weight, complexity, and manufacturing cost of the equipment, but also introduces additional energy consumption and potential points of failure.

[0008] 4. Limited overall cleaning effect: Due to the loss and uneven distribution of vibration energy during transmission, the entire stirring paddle (especially the root) is unable to generate sufficiently strong and uniform vibration, and cannot make full use of efficient cleaning mechanisms such as cavitation effect. The overall self-cleaning effect is difficult to meet the strict requirements for low residue in radioactive waste treatment.

[0009] Therefore, existing radioactive waste cement solidification mixing mechanisms have significant shortcomings in self-cleaning, particularly regarding the issue of residue at the base of the mixing blade and overall cleaning efficiency. There is an urgent need to develop a new self-cleaning solution that can overcome these deficiencies, achieving efficient, uniform, and reliable self-cleaning of the mixing blade (especially at its base), reducing the risk of radioactive contaminant residue, while simultaneously simplifying the structure and reducing costs. Utility Model Content

[0010] The purpose of this invention is to provide a radioactive waste cement solidification and mixing mechanism with ultrasonic self-cleaning function.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function includes a mixing paddle and a mixing drive transmission assembly that drives the mixing paddle to rotate around its axis to achieve the mixing function. The mixing paddle includes a paddle shaft and blades fixed on the paddle shaft. A vibration transmission shaft is rigidly connected to the upper end of the paddle shaft. Both the paddle shaft and the vibration transmission shaft are solid shafts. The vibration transmission shaft is driven to the output end of the mixing drive transmission assembly, and an ultrasonic transducer is fixed to its upper end. The ultrasonic transducer is continuously powered in the rotating state through a slip ring assembly. The high-frequency vibration of the ultrasonic transducer is transmitted to the paddle shaft and blades of the mixing paddle through the vibration transmission shaft, and the self-cleaning of the mixing paddle is achieved through the cavitation effect.

[0013] Furthermore, the stirring drive transmission assembly includes a transmission box, a stirring drive assembly disposed outside the transmission box, and a gear transmission assembly disposed inside the transmission box, wherein the output end of the stirring drive assembly is connected to the input end of the gear transmission assembly.

[0014] Furthermore, the slip ring assembly includes a slip ring rotor end, a slip ring stator end, and a slip ring fixing frame. The slip ring stator end is fixedly connected to the transmission box through the slip ring fixing frame and connected to the ultrasonic generator through a wire. The slip ring rotor end is connected to the ultrasonic transducer through a wire and rotates synchronously with the vibration transmission shaft, so that the ultrasonic transducer is continuously powered while the stirring paddle is rotating.

[0015] Furthermore, the stirring drive assembly includes a motor and a reducer, with the output end of the motor connected to the input end of the reducer, and the output end of the reducer connected to the input end of the gear transmission assembly.

[0016] Furthermore, the rigid connection between the propeller shaft and the vibration transmission shaft is achieved through a flange structure, the flange structure including...

[0017] Transmission flanges are used to transmit torque and withstand high-frequency vibrations;

[0018] Quick-release flange, used to enable quick disassembly and replacement of the agitator;

[0019] The transmission flange is secured to the vibration transmission shaft by radial locking bolts, and the quick-release flange is pressed and secured to the propeller shaft by a plurality of circumferentially distributed high-strength bolts.

[0020] Furthermore, the stirring paddle includes a first stirring paddle and a second stirring paddle. The first stirring paddle includes a first paddle shaft, and a first vibration transmission shaft is rigidly connected to the upper end of the first paddle shaft. The second stirring paddle includes a second paddle shaft, and a second vibration transmission shaft is rigidly connected to the upper end of the second paddle shaft. The gear transmission assembly includes a driving gear, a first driven gear that directly meshes with the driving gear, and a second driven gear that meshes with the first driven gear. The driving gear is driven and connected to the output end of the reducer. The first vibration transmission shaft passes through the transmission box and is driven and connected to the first driven gear. The second vibration transmission shaft passes through the transmission box and is driven and connected to the second driven gear.

[0021] Furthermore, the vibration transmission shaft is provided with a sealing structure at each point where it passes through the transmission box.

[0022] Furthermore, the stirring paddle is a double-helix stirring paddle.

[0023] Furthermore, the ultrasonic transducer operates at a frequency of 20–130 kHz and has a vibration amplitude of 5–100 μm.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] 1. High-efficiency self-cleaning across the entire area: The ultrasonic transducer directly drives the vibration transmission shaft to generate high-frequency vibration, so that the vibration energy is evenly transmitted along the solid shaft to the root of the impeller and the entire area of ​​the impeller blade. This overcomes the energy attenuation problem of the traditional eccentric block mechanical vibration scheme, and achieves cavitation cleaning of the impeller (especially the root) without dead corners, significantly reducing the risk of radioactive contaminant residue.

[0026] 2. Simplified structure and improved reliability: The use of an ultrasonic transducer to replace the eccentric block mechanism eliminates the need for the vibration motor, hollow shaft and internal transmission components in the traditional solution, making the propeller shaft a solid structure, which greatly reduces the difficulty of processing (avoiding precision welding) and the failure rate, and improves the overall rigidity and service life of the equipment.

[0027] 3. Reduced cost and energy consumption: The use of ultrasonic transducers instead of traditional mechanical vibration motors reduces the need for two vibration motors. The ultrasonic transducers are powered only through slip ring assemblies, reducing equipment purchase costs and energy consumption, while simplifying electrical wiring.

[0028] 4. Integrated mixing and cleaning functions: The vibration transmission shaft simultaneously undertakes the dual functions of power transmission (driving the mixing paddle to rotate) and vibration transmission (self-cleaning). It achieves real-time ultrasonic cleaning under mixing conditions through dynamic power supply via slip ring, eliminating the need to stop the machine for cleaning and improving the continuity of operation.

[0029] 5. Directional enhancement of cavitation effect: The high-frequency vibration (20-130kHz) of the ultrasonic transducer creates a continuous cavitation effect on the surface of the stirring paddle, which specifically cleans the adhering radioactive cement mixture, greatly improving the cleaning efficiency compared to mechanical vibration. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the radioactive waste cement solidification and mixing mechanism with ultrasonic self-cleaning function in Example 1.

[0031] Figure 2 This is a side view of the radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function in Example 1.

[0032] Figure 3 for Figure 2 AA sectional view.

[0033] In the diagram: 11-Motor; 12-Gear reducer;

[0034] 21-Transmission box; 22-Driving gear; 23-First driven gear; 24-Second driven gear;

[0035] 31 - First vibration transmission shaft; 32 - Second vibration transmission shaft;

[0036] 41-Ultrasonic transducer; 42-Slip ring stator end; 43-Slip ring rotor end; 44-Slip ring mounting bracket;

[0037] 51-First agitator; 511-First impeller shaft; 512-First impeller blade; 52-Second agitator; 521-Second impeller shaft; 522-Second impeller blade;

[0038] 61-Transmission flange; 62-Quick-release flange;

[0039] 71-Sealed structure. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to specific implementation methods and embodiments. It should be understood that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-substantial improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] Example 1

[0048] See Figures 1-3 This embodiment provides a radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function, including...

[0049] The stirring drive transmission assembly includes a transmission housing 21, a stirring drive assembly disposed outside the transmission housing 21, and a gear transmission assembly disposed inside the transmission housing 21. The stirring drive assembly includes a motor 11 and a reducer 12, with the output end of the motor 11 connected to the input end of the reducer 12. The gear transmission assembly includes a driving gear 22, a first driven gear 23 directly meshing with the driving gear 22, and a second driven gear 24 meshing with the first driven gear 23. The driving gear 22 is drivenly connected to the output end of the reducer 12.

[0050] The stirring paddle includes a first stirring paddle 51 and a second stirring paddle 52, both of which are double-helix stirring paddles. The first stirring paddle 51 includes a first paddle shaft 511 and a first blade 512 fixed on the first paddle shaft 511, with a first vibration transmission shaft 31 rigidly connected to the upper end of the first paddle shaft 511. The second stirring paddle 52 includes a second paddle shaft 521 and a second blade 522 fixed on the second paddle shaft 521, with a second vibration transmission shaft 32 rigidly connected to the upper end of the second paddle shaft 521. The first paddle shaft 511, the first vibration transmission shaft 31, the second paddle shaft 521, and the second vibration transmission shaft 32 are all solid shafts. The first vibration transmission shaft 31 passes through the upper and lower bottom surfaces of the transmission box 21 and is driven by a first driven gear 23 inside the transmission box 21. The second vibration transmission shaft 31... The guide shaft 32 passes through the upper and lower bottom surfaces of the transmission box 21 and is driven and connected to the second driven gear 24 inside the transmission box 21. Ultrasonic transducers are fixed at the top of both the first and second vibration transmission shafts. Taking the ultrasonic transducer 41 fixed at the top of the second vibration transmission shaft 32 as an example, the ultrasonic transducer 41 is continuously powered in the rotating state through the slip ring assembly. The slip ring assembly includes a slip ring stator end 42, a slip ring rotor end 43 and a slip ring fixing frame 44. The slip ring stator end 42 is fixedly connected to the transmission box 21 through the slip ring fixing frame 44 and connected to the ultrasonic generator (not shown in the figure) through a wire. The slip ring rotor end 43 is connected to the ultrasonic transducer 41 through a wire and rotates synchronously with the second vibration transmission shaft 32 so that the ultrasonic transducer 41 is continuously powered in the rotating state of the second stirring paddle 52.

[0051] In this embodiment, the rigid connection between the first propeller shaft 511 and the first vibration transmission shaft 31, and the rigid connection between the second propeller shaft 521 and the second vibration transmission shaft 32, are achieved through a flange structure. Taking the flange structure connecting the second propeller shaft 521 and the second vibration transmission shaft 32 as an example, the flange structure includes a transmission flange 61 for transmitting torque and withstanding high-frequency vibration, and a quick-release flange 62 for realizing the quick disassembly and replacement of the agitator. The transmission flange 61 locks the quick-release flange 62 to the second vibration transmission shaft 32 with radial locking bolts. The locking direction of the radial locking bolts is perpendicular to the axis of the second vibration transmission shaft 32, and the number of bolts is ≥4. The quick-release flange 62 is pressed and fixed to the second propeller shaft 521 by a plurality of circumferentially distributed high-strength bolts.

[0052] In this embodiment, both the first and second vibration transmission shafts have sealing structures at the points where they pass through the transmission box 21.

[0053] In a preferred embodiment of this invention, the ultrasonic transducer can be configured to operate over a wide frequency range (20–130 kHz), and its vibration amplitude can be flexibly adjusted (5–100 μm). By dynamically modulating the output frequency through the ultrasonic generator, the transducer excites a continuous and stable cavitation effect on the surface of the stirring paddle, which can effectively remove residual radioactive contaminants.

[0054] For radioactive mixtures with different characteristics, ultrasonic transducers with specific frequency response characteristics can be selected for adaptation. Especially for contaminants with specific radioactive properties, selecting an ultrasonic operating frequency adapted to their physical characteristics can significantly improve cleaning efficiency (e.g., for contaminants with alpha radioactivity, an ultrasonic transducer with an operating frequency of 40–45 kHz can be selected). Typical applications include, but are not limited to, targeted treatment schemes for specific types of radioactive contaminants.

[0055] The high-frequency vibration of the ultrasonic transducer creates a continuous cavitation effect on the surface of the agitator, which can decompose radioactive materials remaining on the surface of the agitator. The ultrasonic frequency can be tuned by an ultrasonic generator. For specific radioactive materials, an ultrasonic transducer with a matching ultrasonic frequency can be selected to specifically decompose the adhering radioactive cement mixture. For example, for alpha-radioactive pollutants, an ultrasonic transducer with a matching ultrasonic frequency of 40 to 45 kHz can be selected to better decompose the residual alpha-radioactive pollutants.

[0056] The working process of the above-mentioned radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function is as follows:

[0057] 1. The steel drum is transferred to the mixing station via a transfer mechanism, and the mixing mechanism is lowered to the mixing position;

[0058] 2. Start the motor 11. The motor 11 drives the drive gear 22 to rotate through the reducer 12. The first driven gear 23 and the second driven gear 24 mesh in series to realize the forward and reverse rotation of the first stirring paddle 51 and the second stirring paddle 52 (both are double helical stirring paddles), so as to realize the forced convection mixing of cement and radioactive waste in the steel drum and achieve uniform mixing for cement solidification. At the same time, the first stirring paddle 51 and the second stirring paddle 52 revolve around the output shaft of the reducer 12, so that the stirring mechanism covers the entire steel drum when the cement solidifies.

[0059] 3. After the cement in the steel drum has solidified and been mixed, turn on the ultrasonic generator. The high-frequency current is transmitted from the stator end 42 of the slip ring to the mover end 43 of the slip ring to the ultrasonic transducer 41. The ultrasonic transducer 41 converts the electrical energy into high-frequency vibration of 20-130kHz, which is transmitted to the stirring paddle below through the vibration transmission shaft. The high-frequency vibration causes microbubbles to burst (cavitation) on the surface of the paddle blades, generating local high-pressure shock waves (≥50MPa), which peel off and decompose the residual cement-radioactive mixture, thus achieving self-cleaning of the stirring paddle.

[0060] Furthermore, it should be understood that after reading the above teachings of this utility model, those skilled in the art can make various alterations or modifications to this utility model, and these equivalent forms also fall within the scope defined by the claims of this application.

Claims

1. A radioactive waste cement solidification mixing mechanism with ultrasonic self-cleaning function, characterized in that, The device includes a stirring paddle and a stirring drive transmission assembly that drives the stirring paddle to rotate around its axis to achieve a stirring function. The stirring paddle includes a paddle shaft and blades fixed on the paddle shaft. A vibration transmission shaft is rigidly connected to the upper end of the paddle shaft. Both the paddle shaft and the vibration transmission shaft are solid shafts. The vibration transmission shaft is driven to the output end of the stirring drive transmission assembly, and an ultrasonic transducer is fixed to its upper end. The ultrasonic transducer is continuously powered in the rotating state through a slip ring assembly. The high-frequency vibration of the ultrasonic transducer is transmitted to the paddle shaft and blades of the stirring paddle through the vibration transmission shaft, and the stirring paddle achieves self-cleaning through cavitation effect.

2. The stirring mechanism of claim 1, wherein The stirring drive transmission assembly includes a transmission box, a stirring drive assembly disposed outside the transmission box, and a gear transmission assembly disposed inside the transmission box. The output end of the stirring drive assembly is connected to the input end of the gear transmission assembly.

3. The stirring mechanism of claim 2, wherein, The slip ring assembly includes a slip ring rotor end, a slip ring stator end, and a slip ring fixing frame. The slip ring stator end is fixedly connected to the transmission box through the slip ring fixing frame and connected to the ultrasonic generator through a wire. The slip ring rotor end is connected to the ultrasonic transducer through a wire and rotates synchronously with the vibration transmission shaft so that the ultrasonic transducer is continuously powered while the stirring paddle is rotating.

4. The stirring mechanism of claim 2, wherein The stirring drive assembly includes a motor and a reducer. The output end of the motor is connected to the input end of the reducer, and the output end of the reducer is connected to the input end of the gear transmission assembly.

5. The stirring mechanism according to claim 1, characterized in that, The rigid connection between the propeller shaft and the vibration transmission shaft is achieved through a flange structure, which includes... Transmission flanges are used to transmit torque and withstand high-frequency vibrations; Quick-release flange, used to enable quick disassembly and replacement of the agitator; The transmission flange is secured to the vibration transmission shaft by radial locking bolts, and the quick-release flange is pressed and secured to the propeller shaft by a plurality of circumferentially distributed high-strength bolts.

6. The stirring mechanism of claim 4, wherein The stirring paddle includes a first stirring paddle and a second stirring paddle. The first stirring paddle includes a first paddle shaft, and a first vibration transmission shaft is rigidly connected to the upper end of the first paddle shaft. The second stirring paddle includes a second paddle shaft, and a second vibration transmission shaft is rigidly connected to the upper end of the second paddle shaft. The gear transmission assembly includes a driving gear, a first driven gear that directly meshes with the driving gear, and a second driven gear that meshes with the first driven gear. The driving gear is driven and connected to the output end of the reducer. The first vibration transmission shaft passes through the transmission box and is driven and connected to the first driven gear. The second vibration transmission shaft passes through the transmission box and is driven and connected to the second driven gear.

7. The stirring mechanism of claim 2, wherein The vibration transmission shaft is equipped with a sealing structure at each point where it passes through the transmission box.

8. The stirring mechanism of claim 1, wherein The agitator is a double-helix agitator.

9. The stirring mechanism of claim 1, wherein The ultrasonic transducer operates at a frequency of 20–130 kHz and has a vibration amplitude of 5–100 μm.

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