A radioactive immersed waste resin drying device and drying method

Abstract

The present invention discloses a radioactive waterlogged waste resin drying device and a drying method. The drying device includes a conical vacuum tank, a water drainage module, a heating module, a steam condensation module, a terahertz drying detection module, and a non-condensable gas compression and return module. The non-condensable gas compression and return module is connected to the steam condensation module, and the non-condensable gas separated by the steam condensation module is introduced into the conical vacuum tank through the compressed gas inlet of the conical vacuum tank, so as to improve the drying efficiency of radioactive resin waste liquid and realize gas purging. The drying device provided by the present invention, which can monitor the water content in real time based on terahertz spectroscopy, can quickly dry radioactive waterlogged waste resin by combining ultrasonic wave and non-condensable gas return technology, and has the characteristics of high efficiency, energy saving, safety, precision and strong sustainability, thus solving the defects of the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field related to the treatment of radioactive immersion waste resin of nuclear waste. More specifically, it particularly relates to a drying detection and drying device for nuclear waste. Background Art

[0002] The resin used in nuclear power plants is mainly ion exchange resin, whose main function is to purify water quality, especially to remove impurity ions in water, such as radionuclides, corrosive ions (such as sodium ions, chloride ions), etc. This is crucial for ensuring the safe operation of the reactor and preventing equipment corrosion. After use, the waste resin becomes a radioactive hazardous waste due to adsorbing a large amount of radioactive substances. The immersion waste resin in nuclear power plants is commonly treated by solidification, that is, mixing the radioactive waste resin with a solidifying agent such as cement to reduce the leakage risk; however, the disadvantage is that the solidified volume is large, taking up a lot of land for long-term storage, and there is a potential risk of radioactive substance migration, and the treatment cost is also relatively high.

[0003] By treating the immersion waste resin through the drying compression volume reduction technology, the disadvantages of the solidification technology can be effectively overcome. The volume reduction ratio of the immersion waste resin after drying and compression can reach more than 3, which can significantly reduce the volume of radioactive waste resin in nuclear power plants, reduce transportation and disposal costs, and enhance the safety and sustainability of nuclear power plant operation. However, the drying compression volume reduction process may cause the release of radioactive substances and volatile organic compounds during the treatment process, posing potential health and safety risks to operators and the surrounding environment. Therefore, the fundamental problem to be solved lies in how to ensure the safety of the treatment process while achieving effective volume reduction of the waste resin, maximize the control and prevention of the leakage of radioactive substances and harmful gases, protect the health of operators, and reduce the potential impact on the surrounding environment. At the same time, it is necessary to consider the economy and feasibility of the process to achieve the overall optimization of waste resin treatment. The technical solution disclosed in Patent No. 201210180190.0 has many operation steps and a complex process, requires professional personnel to operate, is not suitable for large-scale industrial application, and the treatment efficiency may be low. In the technical solution disclosed in Patent No. 201611049945.8, problems such as the need for additional treatment of nitrogen pollution in the nitrogen purging system, undetected moisture drying, and insufficient water drainage process may affect the drying effect and safety. Patent No. 202011180222.8 uses a water filtering part to preliminarily dehydrate the waste resin to increase the water drainage efficiency. Essentially, it uses gravity dehydration and cannot remove the capillary water between resin particles. Therefore, the water drainage effect is still limited.

[0004] Based on the limitations and deficiencies of the existing technology, there is an urgent need to develop a drying detection and drying device for nuclear waste to achieve efficient, real-time, and accurate control of the drying process, reduce energy consumption while ensuring the volume reduction quality, reduce the costs of waste treatment and disposal, thereby improving the overall treatment efficiency and promoting the sustainable development of radioactive waste management. Summary of the Invention

[0005] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a drying device and a drying method for radioactive water-soaked waste resin that reduce costs and increase efficiency.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] The present invention first provides a drying device for radioactive water-soaked waste resin, including:

[0008] A conical vacuum tank, including a feed inlet, a discharge outlet, an exhaust gas outlet and a compressed gas inlet, and the conical vacuum tank is used to store waste resin liquid during vacuum drying;

[0009] A water drainage module, including a negative pressure pumping unit for removing free water and an ultrasonic dehydration unit for removing capillary water; the negative pressure pumping unit is connected to the upper end of the discharge outlet of the conical vacuum tank, and the ultrasonic dehydration unit is arranged inside the conical vacuum tank; the water drainage module is used to drain the water in the resin liquid waste to reduce the influence of water on the drying process;

[0010] A heating module, arranged on the conical vacuum tank, and the heating module is used to provide heat to promote the evaporation of water in the resin liquid waste;

[0011] A steam condensation module, connected to the exhaust gas outlet of the conical vacuum tank, and is used to liquefy the exhaust gas generated by the heating module to eliminate the radioactive pollution of the exhaust gas;

[0012] A terahertz drying detection module, arranged outside the conical vacuum tank, and is used to monitor the moisture content during the drying process of the resin liquid waste;

[0013] A non-condensable gas compression and return module, connected to the steam condensation module, and introduces the non-condensable gas separated by the steam condensation module into the conical vacuum tank through the compressed gas inlet of the conical vacuum tank to improve the drying efficiency of the radioactive resin liquid waste and realize gas purging.

[0014] The present invention also provides a drying method for radioactive water-soaked waste resin, including:

[0015] The first step: tank washing and vacuum pumping treatment;

[0016] Step 2: Feeding and draining: The soaked waste resin enters the interior of the conical vacuum tank through the feed port of the conical vacuum tank. At the same time, the pneumatic diaphragm pump and the ultrasonic transducer are started. The pneumatic diaphragm pump generates negative pressure through the reciprocating motion of the diaphragm, thereby sucking in and discharging the liquid. The ultrasonic transducer utilizes the cavitation effect caused by the propagation of ultrasonic waves in the liquid. When ultrasonic waves pass through the liquid, periodic high-pressure and low-pressure regions are formed, resulting in the formation of tiny bubbles in the liquid. As the bubbles continuously grow and collapse, a huge amount of energy is released, thereby breaking the capillary water between the resin particles.

[0017] Step 3: Vacuum drying and terahertz real-time detection: Start the variable-speed motor to drive the double-screw rod to work through the magnetic coupling, stir the waste resin, start the hot oil machine to heat the oil in the interlayer of the conical vacuum tank, and at the same time start the terahertz drying detection module to detect the drying degree of water. And the terahertz drying detection module adjusts the heating degree of the hot oil machine according to the water distribution in the resin.

[0018] Step 4: Steam condensation and non-condensable gas compression and recycling: During the drying process, the steam enters the steam condensation module for condensation, and the non-condensable gas enters the non-condensable gas compression and recycling module for recovery and compression utilization. In the later stage of drying, the compressed non-condensable gas enters the annular gas spray tray to provide an air flow pulse for Step 3 to strengthen the heat transfer between the waste resin particles.

[0019] In Step 3, the method of terahertz real-time detection is as follows:

[0020] S1. Use terahertz to excite the waste resin to be measured, obtain its spectral data in different drying states, analyze the changes in its absorption peaks and characteristic values, and establish a relationship model between the drying degree of the waste resin and the corresponding terahertz spectral characteristics.

[0021] S2. Load the waste resin sample to be processed into a closed vacuum drying device, execute the drying process according to the established drying procedure, and maintain the stable operation of the drying device.

[0022] S3. Provide a terahertz drying detection module. The terahertz drying detection module utilizes the penetrability of terahertz waves and the characteristics of being sensitive to water molecules, and obtains the spectral data of the sample by measuring the absorption and scattering characteristics of the sample in the terahertz frequency band, thereby real-time monitoring the water content in the substance.

[0023] As a preferred process, in Step S2, the drying procedure includes the following steps:

[0024] A1. Conduct precise temperature control to ensure that it is maintained within a suitable range that can effectively evaporate water without damaging the resin properties.

[0025] A2, adjust the steam condensation rate to match the heat input to prevent the drying efficiency from being affected by too fast or too slow condensation;

[0026] A3, debug the stirring rate to facilitate the uniform distribution of heat and prevent local overheating or caking;

[0027] A4, recycle and regulate the non-condensable steam, reasonably adjust the gas flow rate of the recycled non-condensable steam to ensure the pressure stability in the system, and promote the continuous volatilization of moisture, so as to achieve a better drying effect in the later stage of drying;

[0028] A5, termination of the drying time. The drying time should be set according to the actual drying state to ensure that the required drying degree is achieved within a safe and effective time frame, so as to achieve the optimal drying state of the resin.

[0029] As a preferred process, in step S3, the collected spectral data is stored in a database, and then the spectral data is processed to extract the changes in spectral characteristics during the drying process, and the dynamic change of the moisture content is deduced based on the relationship model between the drying degree of waste resin and the corresponding terahertz spectral characteristics pre-established in step S1.

[0030] As a preferred process, in step S3, according to the obtained terahertz drying detection results, the drying process parameters are dynamically adjusted, including but not limited to controlling the temperature, steam condensation rate, stirring rate, non-condensable steam return gas flow rate and drying time, to optimize the drying efficiency and effect, so as to effectively reduce the moisture residue in the waste resin and ensure the safety and environmental protection of the drying process.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] The drying device of the present invention integrates a water drainage module, a heating module, a steam condensation module, a non-condensable gas compression and return module and a terahertz drying detection module, realizing efficient drying and real-time monitoring. The combination of negative pressure pumping and ultrasonic dehydration makes the removal of free water and capillary water more thorough, improving the drying efficiency. The application of terahertz technology can not only monitor the moisture content in real time, but also dynamically evaluate the drying process to ensure the safety and effectiveness of waste resin treatment. The design of the non-condensable gas compression and return module effectively reduces the radioactive pollution of waste gas and ensures the environmental protection and safety of the operation process. In addition, the annular gas spraying disc generates a gas swirl pulse to excite a cyclone, and then forms a strong cyclone flow. This cyclone can not only quickly increase the gas flow speed, but also effectively dry the resin particles. The overall design improves the automation degree and batch processing capacity of radioactive waste treatment, reduces the operation risk, and has good environmental protection effects and economic benefits.

[0033] Other advantages, objects, and features of the drying device for nuclear waste according to the present invention will be partially reflected in the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of the drying device of the present invention;

[0035] Figure 2 It is a schematic diagram of the working principle of the drying device of the present invention;

[0036] Figure 3 It is a schematic diagram of the structure of the negative pressure water pumping unit of the present invention;

[0037] Figure 4 It is a schematic diagram of the structure of the ultrasonic dehydration unit of the present invention;

[0038] Figure 5 It is a schematic diagram of the structure of the non-condensable gas compression and return module of the present invention;

[0039] Figure 6 It is a schematic diagram of the structure of the conical vacuum tank of the present invention;

[0040] Figure 7 It is a schematic diagram of the structure of the steam condensation module of the present invention;

[0041] Figure 8 is Figure 1 the A-A sectional view of;

[0042] Figure 9 It is a schematic diagram of the structure of the annular gas spraying disc;

[0043] Figure 10 It is a schematic diagram of the detection process of the terahertz drying detection module of the present invention;

[0044] Figure 11 It is a schematic diagram of the process of the drying process of the present invention;

[0045] In the figure: 1. Conical vacuum tank; 11. Magnetic coupler; 12. Feed inlet; 13. Integrated filter; 14. Variable-speed motor; 15. Double-screw rod; 16. Discharge outlet; 2. Drainage module; 21. Negative-pressure water pumping unit; 211. Stainless steel filter mesh; 212. Pneumatic diaphragm pump; 213. Liquid accumulation tank; 214. Negative-pressure water pumping solenoid valve; 22. Ultrasonic dehydration unit; 221. Ultrasonic transducer; 222. Ultrasonic generator; 223. Horn; 224. Vibration rod; 3. Heating module; 4. Steam condensation module; 41. Primary condenser; 411. Wall pipe; 412. Condensing pipe; 42. Primary gas-liquid separator; 43. Secondary condenser; 44. Secondary gas-liquid separator; 45. Vacuum pump; 46. Low-pressure gas storage tank; 47. Compressed air valve; 48. Liquid storage tank; 49. Water level sight glass; 5. Terahertz drying detection module; 51. Terahertz emitter; 52. Detector; 53. Control unit; 54. Data processing unit; 6. Non-condensable gas compression and return module; 61. Compression pump; 62. Compressed gas high-pressure tank; 63. Annular gas spray disc; 631. Annular disc; 632. Airflow nozzle; 64. Air inlet valve. Detailed implementation manners

[0046] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0048] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0049] Figures 1 to 11The structural diagram of a drying device for nuclear waste and the flowchart of a drying method according to an embodiment of the present invention are shown and will be described separately below. It should be noted that these and other subsequent figures are only examples, not drawn under the condition of equal proportion, and should not be used to limit the actual scope of protection required by the present invention.

[0050] This embodiment provides a radioactive waterlogged waste resin drying device. As Figure 1 and Figure 2 shown, the drying device includes a conical vacuum tank 1 for storing waste resin waste liquid during vacuum drying, a water drainage module 2 for discharging the water in the resin waste liquid to reduce the influence of water on the drying process, a heating module 3 for providing heat to promote the evaporation of water in the resin waste liquid, a steam condensation module 4 for liquefying water vapor to eliminate radioactive pollution of exhaust gas, a terahertz drying detection module 5 for real-time monitoring of the drying process of the resin waste liquid, and a non-condensable gas compression and return module 6 for improving the drying efficiency of radioactive resin waste liquid and realizing gas purging.

[0051] Please refer to Figure 2 , the heating module 3 provides a stable heat source for the hot oil in the conical vacuum tank 1 through hot oil heating technology. Hot oil heating is an efficient heat transfer method. After the hot oil is heated to the required temperature in the heating module 3, it is circulated through the pipeline system to the heating jacket in the conical vacuum tank 1. This process ensures uniform temperature distribution in the conical vacuum tank 1 and avoids thermal damage to the resin material caused by excessive temperature difference.

[0052] The water drainage module 2 includes a negative pressure pumping unit 21 for removing free water and an ultrasonic dehydration unit 22 for removing capillary water.

[0053] Please refer to Figure 3, the negative pressure pumping unit 21 includes a stainless-steel filter screen 211, a pneumatic diaphragm pump 212 connected to the inside of the conical vacuum tank 1 through a pipeline, and a liquid accumulation tank 213 for storing free water. In the specific implementation control of the negative pressure pumping unit 21, first, an 80-mesh stainless-steel filter screen 211 needs to be installed on the conical vacuum tank 1 to ensure that the free water entering the negative pressure pumping unit 21 from the conical vacuum tank 1 does not contain large particles and impurities, thus protecting the normal operation of subsequent equipment, especially the pneumatic diaphragm pump 212. Secondly, the type selection of the pneumatic diaphragm pump 212 considers its pumping flow rate and head to meet the needs of actual applications. The control of the pneumatic diaphragm pump 212 can adopt an automated method, using a differential pressure sensor to monitor the negative pressure in the conical vacuum tank 1. When the set negative pressure threshold is reached, the pneumatic diaphragm pump 212 will automatically stop to avoid over-pumping. The design of the liquid accumulation tank 213 should consider the storage safety of free water, and its capacity should be large enough to cope with possible water volume changes. The liquid accumulation tank 213 is equipped with a liquid level sensor for real-time monitoring of the liquid level. When the liquid level reaches the high limit, the water is discharged or transferred to other storage devices through a control valve for subsequent water treatment. A PLC (programmable logic controller) is introduced. The PLC can receive the data input by the sensors and make decisions based on these data. For example, when the accumulated water volume is too large, the control system can issue an alarm to prompt the operator for maintenance or manual intervention. At the same time, the negative pressure pumping unit 21 also includes a negative pressure pumping solenoid valve 214 located between the stainless-steel filter screen 211 and the pneumatic diaphragm pump 212. The negative pressure pumping solenoid valve 214 can automatically open when the system needs to pump water, allowing the filtered water to enter the pneumatic diaphragm pump 212 to ensure the normal operation of the pneumatic diaphragm pump 212. When the set negative pressure threshold is reached or the liquid level is too high, the negative pressure pumping solenoid valve 214 will automatically close to prevent water from flowing into the pneumatic diaphragm pump 212, preventing over-pumping and equipment damage. It should be noted that although the negative pressure pumping unit 21 can remove most of the free water, there is still some free water existing in the form of capillaries between the resin particles.

[0054] Please refer to Figure 4, the ultrasonic dehydration unit 22 utilizes the cavitation effect of ultrasonic waves in liquids to break and discharge the capillary water between resin particles, thereby improving the water drainage effect. Specifically, capillary water is the moisture present in a porous medium due to capillary action. This moisture does not rely on gravity and can resist external negative pressure suction, existing in liquid form through the tiny pores in the medium. In the dehydration and drying of resins, excessive capillary water can affect the efficiency of subsequent processes, leading to problems during the resin treatment process. Ultrasonic dehydration breaks and discharges the capillary water between resin particles by utilizing the cavitation effect generated by ultrasonic waves in liquids. Ultrasonic waves are mechanical waves with a frequency higher than the human audible range. When these mechanical waves propagate into a liquid, they cause instantaneous pressure changes. These changes generate tiny bubbles in the liquid, and these bubbles rapidly expand and contract under the action of the pressure change, forming a cavitation phenomenon. The rapid rupture of cavitation bubbles releases a huge amount of energy, which can not only disrupt the continuity of the liquid but also help peel the capillary water between resin particles from the particle surface. Under the action of ultrasonic waves, the resin particles are vibrated and impacted, effectively reducing the water tension between the particles and making the capillary water originally trapped between the particles easier to be discharged. In addition, ultrasonic waves can promote the circulation of the liquid and the transfer of kinetic energy, enhancing the fluidity of the water. In this way, not only is the dehydration efficiency improved, but the processing time is reduced, the energy consumption is lowered, providing more ideal pre-drying conditions for the subsequent treatment of resins.

[0055] The terahertz drying detection module 5 includes a terahertz emitter 51, a detector 52, a control unit 53, and a data processing unit 54; the terahertz emitter 51 generates terahertz waves with a frequency range between 0.1 and 10 THz. When the sample is irradiated with the terahertz waves, some of the energy in the waves is absorbed or scattered by the sample, and the remaining part is received by the detector; the detector 52 converts the received terahertz signal into an electrical signal, and this electrical signal contains information about the internal structure and moisture content of the sample; the control unit 53 is responsible for coordinating the synchronous operation of the terahertz emitter and the detector to ensure the efficient operation of the entire system; the data processing unit 54 analyzes and processes the signals from the detector 52, compares the differences between the incident and transmitted waves, and evaluates the drying degree of the sample. Specifically, the implementation process of the terahertz drying detection module 5 is mainly reflected in the acquisition, analysis of the terahertz waveform, and evaluation of the drying degree. First, the terahertz emitter 51 generates terahertz waves with a frequency range between 0.1 and 10 THz, and these waves irradiate the sample to be measured with a certain penetration power. During the irradiation process, the moisture and other components inside the sample will absorb and scatter the terahertz waves to different degrees, resulting in waveform differences between the incident wave and the transmitted wave. These reactions are due to the change in the electromagnetic characteristics of the sample caused by the presence of moisture. Then, the detector 52 is responsible for receiving the remaining terahertz signals that are not absorbed or scattered by the sample and converting them into electrical signals. During this process, the information contained in the electrical signals can reveal the internal structural characteristics and moisture content of the sample. For example, when the moisture content of the sample is high, the absorption of terahertz waves will be significantly enhanced, resulting in a decrease in the amplitude of the transmitted signal; on the contrary, when the drying degree of the sample increases, the amplitude of the transmitted signal will relatively increase. Subsequently, under the coordination of the control unit 53, the data processing unit 54 begins to deeply analyze the signals obtained by the detector 52. Here, the data processing unit 54 extracts characteristic parameters, such as the amplitude, frequency distribution, and phase information of the waveform, by comparing the waveforms of the incident wave and the transmitted wave. These parameters not only reflect the microscopic structure of the sample but also provide intuitive information related to the moisture content. The literature (Bu Zhengyan. Research on the Detection Method of Crop Leaf Moisture Based on Terahertz Imaging Technology [D]. Jiangnan University, 2018) adopts a transmission detection method, uses a terahertz imaging detection system to measure the terahertz spectra of the whole leaves of two crops, soybean and pepper, respectively, extracts the characteristic parameters under different imaging modes, uses the PCA method to reduce the dimensionality of the frequency-domain spectral data, selects the moisture-sensitive bands, and combines the correlation analysis method for analysis, and respectively establishes the moisture content prediction models of soybean and pepper leaf samples through MLR. The method of extracting the characteristic parameters under different imaging modes and using the PCA method to reduce the dimensionality of the frequency-domain spectral data in this literature is also applicable to the data processing of the moisture content of radioactive immersed waste resin.

[0056] Please refer to Figure 5, the non-condensable gas compression and return module 6 includes a compression pump 61 for compressing non-condensable gas, a compressed gas high-pressure tank 62 connected to the outlet end of the compression pump 61, an annular gas injection disk 63 for generating gas swirl pulses, and an air intake valve 64 for controlling the opening and closing of the annular air flow; one end of the annular gas injection disk 63 communicates with the inner cavity surface of the conical vacuum tank 1, and the other end is first connected to the air intake valve 64 and then communicates with the compressed gas high-pressure tank 62. Specifically, as a specific implementation manner, the main function of the compression pump 61 is to effectively compress the non-condensable gas and transport the compressed gas to the compressed gas high-pressure tank 62 through its outlet end. In the compressed gas high-pressure tank 62, the gas is stored and maintained at a relatively high pressure state for subsequent use. The structure of the annular gas injection disk 63 allows the gas to form swirl pulses in the disk. Using the principle of gas dynamics, the formation of the gas swirl is similar to the beating of the heart. In this process, the non-condensable gas enters the inner cavity of the conical vacuum tank 1 through one end of the disk. In this area, the formation of the gas swirl can generate significant kinetic energy and momentum, promoting heat exchange and mass transfer between the gas and solid particles. Please refer to Figure 6 , the annular gas injection disk 63 excites the gas swirl to rotate by generating gas swirl pulses, and then forms a strong gas swirl flow. This gas swirl can not only quickly increase the air flow speed but also effectively dry the resin particles. When the air flow rotates, due to the action of centrifugal force, the gas swirl can quickly take away the moisture in the resin particles, achieving efficient drying. In addition, through the control of the air intake valve 64, the opening and closing of the air flow can be flexibly adjusted to meet the requirements under different working conditions, improving the stability and adaptability of the system. On the other hand, the purging of the inner part of the empty conical vacuum tank 1 is also one of the important applications of the non-condensable gas compression and return. For the purging of the inner part of the empty conical vacuum tank 1, applying the non-condensable gas compression and return technology can effectively remove the residual gas and pollutants in the tank of the conical vacuum tank 1, ensuring the safety and reliability of subsequent operations. Of course, when the pressure inside the compressed gas high-pressure tank 62 is too high, part of the gas can be transferred to other storage tanks.

[0057] Please refer to Figure 6 , as a preferred embodiment, a magnetic coupler 11, a feed inlet 12, and an integrated filter 13 for preventing fine waste resin particles from entering the steam condensation module 4 are installed on the upper surface of the conical vacuum tank 1; one end of the magnetic coupler 11 is installed with a variable-speed motor 14 capable of regulating the rotation speed, and the working end of the variable-speed motor 14 is arranged inside the magnetic coupler 11. At the working end of the variable-speed motor 14, the other end of the magnetic coupler 11 is installed with a double-screw rod 15 in the inner cavity of the conical vacuum tank 1. The driving end of the double-screw rod 15 is magnetically coupled to the driving end of the variable-speed motor 14 through the magnetic coupler 11; a discharge port 16 is provided at the lower end of the conical vacuum tank 1.

[0058] As a preferred embodiment, the ultrasonic dehydration unit 22 includes an ultrasonic transducer 221 mounted on the housing of the magnetic coupler 11 for converting high-frequency current into mechanical vibration. One end of the ultrasonic transducer 221 is mounted with an ultrasonic generator 222 for generating high-frequency current, and the other end of the ultrasonic transducer 221 is mounted with a horn 223 for amplifying the ultrasonic amplitude. The other end of the horn 223 is mounted with a vibration rod 224 for increasing the ultrasonic amplitude range.

[0059] Please refer to Figure 7 , as a preferred embodiment, the steam condensation module 4 includes a primary condenser 41, a primary gas-liquid separator 42, a secondary condenser 43 for secondary condensation of steam, a secondary gas-liquid separator 44, a vacuum pump 45 for pumping air and evacuating, and a low-pressure gas storage tank 46 for temporarily storing non-condensable gases, which are connected in sequence. A liquid storage tank 48 is provided at the bottom of the primary condenser 41, and the liquid storage tank 48 is also connected to the primary gas-liquid separator 42, the secondary condenser 43, and the secondary gas-liquid separator 44. Specifically, the main function of the primary condenser 41 is to cool the incoming steam to a temperature close to the condensation temperature through a cooling medium, thereby achieving the preliminary condensation of the steam. A liquid storage tank 48 is provided at the bottom of the primary condenser 41 for collecting the condensed liquid substances. The primary gas-liquid separator 42 is connected after the primary condenser 41 and is mainly used for separating the liquid and the uncondensed gas. Through the action of gravity and centrifugal force, the device can effectively separate the condensate from the gas, achieving a good separation of the gas phase and the liquid phase in terms of physical properties. Then, the steam that fails to condense in the primary condenser 41 in time enters the secondary condenser 43, where the steam is further cooled and condensed again. Immediately following is the secondary gas-liquid separator 44, which is responsible for separating the liquid and the non-condensable gas from the gas-liquid mixture discharged from the secondary condenser 43 again. The vacuum pump 45 is responsible for pumping out the air and other gases in the conical vacuum tank 1 to achieve the required vacuum state. Vacuum evaporation utilizes the vacuum environment to lower the boiling point of the liquid, thereby achieving an efficient evaporation process. In a specific implementation, the inside of the conical vacuum tank 1 is first evacuated by the vacuum pump 45, and then the liquid to be evaporated is heated, causing it to rapidly turn into steam under low pressure and then be condensed and collected. The low-pressure gas storage tank 46 is responsible for temporarily storing non-condensable gases for subsequent treatment or recycling.

[0060] The low-pressure gas storage tank 46 is connected to the compression pump 61 through a pressure control valve 47, and the outlet end of the compression pump 61 is connected to the compressed gas high-pressure tank 62 to ensure the smooth progress of the gas flow process from low pressure to high pressure. Specifically, when the compression pump 61 is operating, it sucks in the low-pressure gas from the low-pressure gas storage tank 46 and compresses it into high-pressure gas through the conversion of mechanical energy and then flows into the compressed gas high-pressure tank 62.

[0061] In terms of installation, to ensure the safety and airtightness of the system, strict sealing measures are taken during installation to avoid the risk of gas leakage. For the tank body, lead sealing can be used for radiation protection. To monitor and observe the liquid level status in real time, a liquid level gauge and a sight glass are installed on the tank body. The liquid level gauge can accurately measure the height of the liquid in the tank through sensors and instruments, and output an electrical signal to the control system, thereby realizing automatic monitoring and alarm. The sight glass provides a direct visual channel, enabling operators to conveniently observe the status of the liquid in the tank. Through these two devices, abnormal liquid levels can be detected in a timely manner, preventing accidents such as overlimit and overflow, and improving operation safety and process efficiency.

[0062] The drying method of radioactive immersed waste resin of the present invention comprises the following steps:

[0063] The first step: tank washing and vacuum pumping. The empty conical vacuum tank 1 is pre-treated by introducing non-condensable gas for preliminary purging to reduce the concentration of residual gas in the tank. Subsequently, the annular gas spray disc 63 is started, and the generated gas pulses form strong turbulence in the tank, which can entrain the residual gas and pollutants into the flow, further enhancing the cleaning effect. After tank washing, the air inlet valve 64 is closed and the vacuum pump 45 is started to gradually evacuate the gas inside the conical vacuum tank 1. The gas is preliminarily filtered through the integrated filter 13 to remove possible particles and impurities, and then enters the low-pressure gas storage tank 46 through the steam condensation module 4. As the vacuum pump 45 continues to operate, the gas pressure inside the conical vacuum tank 1 gradually decreases, and finally reaches an ideal vacuum state of about 0.1 - 10 mbar.

[0064] The second step: feeding and water drainage. The immersed waste resin enters the inside of the conical vacuum tank 1 through the feed port 12 of the conical vacuum tank 1, and at the same time, the pneumatic diaphragm pump 212 and the ultrasonic transducer 221 are started. The pneumatic diaphragm pump 212 generates negative pressure through the reciprocating motion of the diaphragm, thereby sucking and discharging the liquid. The core of ultrasonic dehydration is to utilize the cavitation effect caused by the propagation of ultrasonic waves in the liquid. When ultrasonic waves pass through the liquid, periodic high-pressure and low-pressure regions are formed, resulting in the formation of tiny bubbles in the liquid. As the bubbles continuously grow and collapse, a huge amount of energy is released, thereby breaking the capillary water between the resin particles. The entire dehydration process is a dynamic cycle. When the pneumatic diaphragm pump 212 pumps the water out to the liquid accumulation bucket, the vibration of the ultrasonic waves still continues to play a role, ensuring that the moisture in the resin particles can be discharged at a relatively fast speed until the water is completely pumped out, and then the dehydration process stops. Through the collaborative work of the pneumatic diaphragm pump 212 and ultrasonic waves, seamless connection from rough dehydration to fine dehydration is achieved. After dehydration is completed, the pneumatic diaphragm pump 212 and the ultrasonic transducer 221 are closed.

[0065] Step 3: Vacuum drying and terahertz real-time detection. Start the variable-speed motor 14 to drive the double-screw rod 15 to work through the magnetic coupling 11, stir the waste resin, start the hot oil machine to heat the oil in the interlayer of the conical vacuum tank 1, and at the same time start the terahertz drying detection module 5 to detect the drying degree of water. The terahertz drying detection module 5 can adjust the heating degree of the hot oil machine according to the water distribution in the resin. The terahertz drying detection module 5 does not have to be set for real-time detection and can be set to detect once every interval of not less than 5 minutes.

[0066] As Figure 10 shown, the drying detection method based on terahertz spectroscopy provided by the present invention includes:

[0067] S1. Use terahertz to excite the waste resin to be tested, obtain its spectral data in different drying states, analyze the changes in its absorption peaks and characteristic values, and establish a relationship model between the drying degree of the waste resin and the corresponding terahertz spectral characteristics;

[0068] S2. Load the waste resin sample to be processed into a closed vacuum drying device, perform the drying process according to the established drying procedure, and maintain the stable operation of the drying device;

[0069] S3. Provide a terahertz drying detection module. The terahertz drying detection module utilizes the penetrability of terahertz waves and the characteristics of being sensitive to water molecules, and obtains the spectral data of the sample by measuring the absorption and scattering characteristics of the sample in the terahertz frequency band, so as to monitor the water content in the substance in real time.

[0070] Specifically, the relationship model between the drying degree of the waste resin and the corresponding terahertz spectral characteristics is obtained through the following steps: First, a series of waste resin samples with different drying degrees need to be prepared to ensure that each sample is consistent in thickness and shape for easy comparison and analysis of terahertz spectra. Place the samples in a terahertz spectrometer respectively to obtain the terahertz spectral data in each drying state. Next, process the obtained spectral data, focusing on the changes in absorption peaks and characteristic values. Through spectral analysis techniques, extract the characteristic values such as the position, intensity, and width of the absorption peaks in each drying state, where these characteristic values can reflect the relationship between the water content and the drying degree of the waste resin. Then, use statistical analysis methods to correlate the extracted spectral characteristic values with the corresponding drying degrees to establish a relationship model. The accuracy and reliability of the model can be evaluated through cross-validation, so as to ensure the adaptability and generalization of the model to different samples. Finally, using the established relationship model, a rapid evaluation of waste resin samples with unknown drying degrees can be achieved.

[0071] As a preferred embodiment, as Figure 11 shown, in step S2, the drying procedure includes the following steps:

[0072] A1. Precisely control the temperature to ensure it is maintained within a suitable range that can effectively evaporate moisture without damaging the resin properties. In process step A1, to achieve precise control of the hot oil heating temperature, a high-precision temperature sensor is used to continuously monitor the hot oil temperature to ensure the accuracy and immediacy of the data. Next, the power output of the heater is adjusted through negative feedback to maintain the temperature within the set range. Special attention should be paid to the resin properties to determine a suitable temperature range, usually between 80°C and 120°C, which can effectively evaporate moisture without damaging the resin.

[0073] A2. Adjust the steam condensation rate to match the heat input to prevent the drying efficiency from being affected by too fast or too slow condensation. In process step A2, to adjust the steam condensation rate to match the heat input, first, an accurate assessment of the system's heat load is required, which can be achieved by monitoring the steam temperature, steam flow rate, and condensate temperature. Then, using an automated control system, the cooling water flow rate of the condenser is adjusted in real-time to precisely control the steam condensation rate. Specifically, a fuzzy control algorithm is used to precisely adjust the steam condensation rate. Specifically, the steam temperature (ST), steam flow rate (SF), and condensate temperature (CT) are used as the input variables of the fuzzy controller, and the cooling water flow rate of the condenser (CWF) is used as the output variable. Among them, the fuzzy subsets of the steam temperature ST are defined as {low temperature L, medium temperature M, high temperature H}; the fuzzy subsets of the steam flow rate SF are defined as {small flow rate S, medium flow rate M, large flow rate B}; the subsets of the condensate temperature CT are defined as {low temperature L, medium temperature M, high temperature H}. The fuzzy subsets of the output variable cooling water flow rate CWF are defined as {very small VS, small S, medium M, large B, very large VB}. The specific domain ranges of the input and output quantities should be designed according to the actual scenario. The triangular membership function is used to fuzzify the input and output variables. Based on expert experience, a fuzzy rule base is constructed, including 27 rules in the form of "IF ST is H AND SF is B AND CT is H THEN CWF is VB". The Mamdani inference method is used for fuzzy inference, and the centroid method is used for defuzzification to obtain the precise control quantity of the cooling water flow rate. By continuously collecting the system operation parameters, based on the above fuzzy control algorithm, the cooling water flow rate is adaptively adjusted to achieve the dynamic matching of the steam condensation rate and the heat input, and improve the drying efficiency of the system.

[0074] A3. Adjust the stirring rate for uniform heat distribution and prevent local overheating or caking. In step A3, first set the initial rate of the stirring equipment, and then gradually adjust the stirring rate by monitoring the temperature and material state in real time. Visual monitoring equipment can be used to promptly detect local overheating or caking. According to the monitoring data, increase or decrease the stirring rate in a timely manner to ensure uniform distribution of the material and effective heat conduction. Specifically, the dynamic optimization adjustment of the stirring rate can be achieved through the following algorithm: First, set the initial stirring rate , which can be preset according to the type of material, initial temperature, and equipment parameters. Subsequently, introduce a real-time monitoring module, including an array of temperature sensors and visual monitoring equipment, which are respectively used to capture the overall temperature distribution of the material and the local agglomeration state. Measure the temperature T of the waste resin agglomerate using the temperature sensors, and evaluate the caking degree function D in combination with the visual monitoring feedback. Then, adjust the stirring rate through the prior adjustment function .

[0075] A4. Re-introduction and regulation of non-condensable steam. Reasonably adjust the gas flow rate of the re-introduced non-condensable steam to ensure pressure stability in the system and promote continuous water evaporation, thereby achieving a better drying effect. In step A4, establish an accurate gas flow rate control system. By installing a flow meter and a temperature sensor, monitor the gas flow rate and temperature in real time to ensure data accuracy. Secondly, set an appropriate target gas flow rate according to the characteristics of the wet waste resin particles to optimize the water evaporation efficiency, and combine with a control algorithm to adjust the opening of the steam re-introduction valve to form a swirling atmosphere, realizing continuous and efficient evaporation of the wet waste resin particles. Specifically, first, set the initial valve opening M0, which can be preset according to the type of waste resin, water content, and equipment parameters. Subsequently, introduce a terahertz drying detection module to capture the water content of the waste resin and measure the water content Q of the waste resin agglomerate. Adjust the opening of the steam re-introduction valve through the prior adjustment function ΔM = f(T, Q).

[0076] A5. Termination of the drying time. The drying time should be set according to the actual drying state to ensure the required drying degree within a safe and effective time frame, thereby achieving the optimal drying state of the resin. In step A5, first preset the drying time according to the material characteristics and environmental conditions, and then by analyzing the reflection and transmission characteristics of terahertz waves, the water content and drying state of the material can be obtained in real time. Set a drying threshold, and when the water content drops to a predetermined level, automatically terminate the drying process to avoid over-drying.

[0077] As a preferred embodiment, in step S3, the collected spectral data is stored in a database, and then the spectral data is processed to extract the changes in spectral characteristics during the drying process, and the dynamic change of moisture content is derived based on the relationship model between the drying degree of waste resin and the corresponding terahertz spectral characteristics pre-established in step S1. Specifically, during the implementation of the control process, first, an efficient data storage system is established, and the collected spectral data is uploaded to the database through a real-time acquisition system. This system should have high-performance processing capabilities to ensure that a large amount of spectral data can be quickly recorded and archived. Next, for the stored data, the spectral characteristics are processed using the written algorithm, and the key features in the signal, such as absorption peaks and scattering patterns, are extracted through data analysis tools. Then, based on the relationship model between the drying degree of waste resin and terahertz spectral characteristics established in step S1, regression analysis is performed on the extracted spectral characteristics through machine learning or statistical methods to derive the dynamic change of moisture content.

[0078] As a preferred embodiment, in step S3, according to the obtained terahertz drying detection results, the drying process parameters are dynamically adjusted, including but not limited to controlling temperature, steam condensation rate, stirring rate, non-condensable gas recirculation rate, and drying time, to optimize the drying efficiency and effect, thereby effectively reducing the moisture residue in the waste resin and ensuring the safety and environmental protection of the drying process.

[0079] Fourth step: Steam condensation and non-condensable gas compression and recirculation. During the drying process, the steam enters the steam condensation module 4 for condensation, while the non-condensable gas enters the non-condensable gas compression and recirculation module 6 for recovery and compression utilization. In the later stage of drying, the compressed non-condensable gas enters the annular gas spray disc 63 to provide an air flow pulse for the third step, strengthening the heat transfer between waste resin particles. Subsequently, the non-condensable gas will enter the non-condensable gas compression and recirculation module 6 again for recycling, leaving more radionuclides on the resin particles and avoiding excessive volume increase pollution caused by treating the non-condensable gas once it is generated. The water from steam condensation is stored in the liquid storage tank 48, while the non-condensable gas is stored as compressed gas, and when the critical point is reached, they will be diverted and transferred.

[0080] Fifth step: Discharging and barreling. Start the non-condensable gas compression and recirculation module 6 to introduce gas into the conical vacuum tank 1, so that the pressure inside the conical vacuum tank 1 is the same as the outside, connect the radiation-proof stainless steel barrel to the discharge port 16 below the conical vacuum tank 1, and complete the discharging.

[0081] Compared with the technical features of Patent No. 201611049945.8, the drying device of the present invention integrates negative pressure pumping and ultrasonic dehydration technologies on the basis of the prior art, significantly improving the removal efficiency of free moisture in waste resin waste liquid. In addition, the device adopts terahertz drying detection technology, which can realize real-time monitoring of the drying process. This technology can accurately detect the moisture content inside the material, ensure that the moisture removal during the drying process reaches the expected effect, thereby improving the drying accuracy and avoiding subsequent processing problems caused by insufficient or excessive drying. Patent No. 201611049945.8 increases the nuclear pollution source by using nitrogen purging and water washing processes, while in this patent, the non-condensable gas compression and return module 6 returns the compressed non-condensable gas back to the conical vacuum tank 1, which can form a strong swirling effect, improving the mixing uniformity and heat transfer efficiency of the gas in the drying medium. This swirl significantly enhances the gas fluidity in the later stage of drying and improves the energy exchange efficiency of the material to be dried. It can be seen that due to the reduction of gas emissions and nuclear pollution sources, the device reduces the impact on the environment and enhances the environmental protection of industrial production.

[0082] The above description of the present invention with reference to the accompanying drawings is exemplary. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A radioactive water-soaked waste resin drying device, characterized in that: include: A conical vacuum tank, including a feed port, a discharge port, a waste gas outlet and a compressed gas inlet, the conical vacuum tank is used to store waste resin and waste liquid during vacuum drying; The drainage module includes a negative pressure pumping unit for removing free water and an ultrasonic dehydration unit for removing capillary water; the negative pressure pumping unit is connected to the upper end of the discharge port of the conical vacuum tank, and the ultrasonic dehydration unit is arranged in the conical vacuum tank; the drainage module is used to discharge the water in the resin waste liquid to reduce the influence of the water on the drying process; A heating module is arranged on the conical vacuum tank, and is used to provide heat to promote the evaporation of water in the resin waste liquid; A steam condensation module, connected to the exhaust gas outlet of the conical vacuum tank, is used to liquefy the exhaust gas generated by the heating module to eliminate radioactive contamination of the exhaust gas; The terahertz drying detection module is arranged outside the conical vacuum tank and is used to monitor the moisture content of the resin waste liquid during the drying process; The non-condensable gas compression and return module is connected to the steam condensation module, and the non-condensable gas separated by the steam condensation module is introduced into the conical vacuum tank through the compressed gas inlet of the conical vacuum tank, so as to improve the drying efficiency of the radioactive resin waste liquid and realize gas purging; The non-condensable gas compression and re-entry module includes a compression pump, a compressed gas high-pressure tank, an annular gas spray disc and an air induction valve; the compression pump is used to compress the non-condensable gas; the compressed gas high-pressure tank is connected to the outlet end flange of the compression pump; the air induction valve is used to control the opening and closing of the annular airflow; one end of the annular gas spray disc is connected to the inner cavity surface of the conical vacuum tank, and the other end is first connected to the air induction valve and then to the compressed gas high-pressure tank, and the annular gas spray disc is used to generate gas swirl pulses.

2. The radioactive water-soaked waste resin drying device according to claim 1, characterized in that: The negative pressure pumping unit includes a stainless steel filter, a pneumatic diaphragm pump and a liquid accumulation tank. The stainless steel filter is arranged at the upper end of the discharge port of the conical vacuum tank. The pneumatic diaphragm pump is connected to the inside of the conical vacuum tank through the stainless steel filter.

3. The radioactive water-soaked waste resin drying device according to claim 2, characterized in that: The terahertz drying detection module includes a terahertz transmitter, a detector and a data processing unit; the terahertz transmitter generates terahertz waves with a frequency range of 0.1 to 10 THz; the detector receives the remaining terahertz waves passing through the radioactive water-soaked waste resin; the data processing unit processes the signal from the detector to obtain the degree of dryness of the radioactive water-soaked waste resin.

4. The radioactive water-soaked waste resin drying device according to claim 3, characterized in that: A magnetic coupler is installed on the upper surface of the conical vacuum tank, a variable speed motor capable of adjusting the rotation speed is installed at one end of the magnetic coupler, and the working end of the variable speed motor is arranged in the magnetic coupler, and a double helix rod located in the inner cavity of the conical vacuum tank is installed at the other end of the magnetic coupler, and the transmission end of the double helix rod and the transmission end of the variable speed motor are magnetically coupled and connected through the magnetic coupler.

5. The radioactive water-soaked waste resin drying device according to claim 4, characterized in that: The ultrasonic dehydration unit includes an ultrasonic transducer mounted on the housing of the magnetic coupler and used for converting high-frequency current into mechanical vibration.

6. The radioactive water-soaked waste resin drying device according to claim 5, characterized in that: An ultrasonic generator for generating high-frequency current is installed at one end of the ultrasonic transducer, a horn for amplifying ultrasonic amplitude is installed at the other end of the ultrasonic transducer, and a vibrating rod for increasing the ultrasonic amplitude range is installed at the other end of the horn.

7. The radioactive water-soaked waste resin drying device according to claim 1, characterized in that: The steam condensation module includes a primary condenser, a primary gas-liquid separator, a secondary condenser for secondary condensation of steam, a secondary gas-liquid separator, a vacuum pump for evacuating air and a low-pressure gas storage tank for temporarily storing non-condensable gas, which are connected in sequence; a liquid storage tank is provided at the bottom of the primary condenser, and the liquid storage tank is also connected to the primary gas-liquid separator, the secondary condenser and the secondary gas-liquid separator.

8. A method for drying radioactive waterlogged waste resin based on the radioactive waterlogged waste resin drying device according to claim 6 or 7, characterized in that: include: Step 1: Wash the tank and vacuum it; Step 2: Loading and draining: The soaked waste resin enters the conical vacuum tank through the feed port, and the pneumatic diaphragm pump and ultrasonic transducer are started at the same time; the pneumatic diaphragm pump generates negative pressure through the reciprocating motion of the diaphragm, thereby sucking in and discharging the liquid; the ultrasonic transducer uses the cavitation effect caused by the propagation of ultrasonic waves in the liquid. When ultrasonic waves pass through the liquid, periodic high-pressure and low-pressure areas are formed, resulting in the formation of tiny bubbles in the liquid. As the bubbles continue to grow and collapse, huge energy is released, thereby breaking the capillary water between the resin particles; Step 3: Vacuum drying and terahertz real-time detection: Start the variable speed motor to drive the double screw rod to work through the magnetic coupler to stir the waste resin, start the hot oil machine to heat the oil in the interlayer of the conical vacuum tank, and start the terahertz drying detection module to detect the degree of dryness of water. The terahertz drying detection module regulates the heating degree of the hot oil machine according to the distribution of water in the resin; Step 4: Steam condensation and non-condensable gas compression and return: During the drying process, steam enters the steam condensation module for condensation, while non-condensable gas enters the non-condensable gas compression and return module for recovery and compression. In the later stage of drying, the compressed non-condensable gas enters the annular gas spray disk to provide airflow pulses for the third step and enhance the heat transfer between the waste resin particles.

9. The method for drying radioactive water-soaked waste resin according to claim 8, characterized in that: In the third step, the method of terahertz real-time detection is: S1. Using terahertz to stimulate the waste resin to be tested, obtaining its spectral data under different drying conditions, analyzing the changes in its absorption peaks and characteristic values, and establishing a relationship model between the drying degree of the waste resin and the corresponding terahertz spectral characteristics; S2. Place the waste resin sample to be processed into a closed vacuum drying device, perform the drying process according to the established drying process, and maintain the drying device to work smoothly; S3. Provide a terahertz drying detection module, which utilizes the penetrability of terahertz waves and its sensitivity to water molecules, and obtains spectral data of the sample by measuring the absorption and scattering characteristics of the sample in the terahertz frequency band, thereby monitoring the moisture content in the material in real time.

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