Radioactive organic waste liquid rectification device and rectification method

Abstract

The invention discloses a radioactive organic waste liquid rectification device and rectification method, and belongs to the technical field of radioactive waste treatment. Comprising a waste liquid storage tank, a feed liquid delivery pump, short-range molecular distillation equipment, a TBP storage tank, a kerosene storage tank, a first cold trap, a second cold trap, a first-stage filter, a second-stage filter, a heating circulator, a low-temperature circulator, a first cold trap residual liquid collecting tank, a second cold trap residual liquid collecting tank and a vacuum pump, according to the invention, thermal separation of the medium-low radioactive organic waste liquid TBP / OK, low reaction temperature of short-path molecular rectification equipment and rectification of heat-sensitive and high-boiling-point liquid such as the TBP / OK organic waste liquid can be realized under low pressure, the device has the advantages of simple structure, reduced process control points, low energy consumption, high treatment efficiency and safety in operation, radioactive substances after rectification are mainly concentrated in concentrated TBP / OK, and the production cost is reduced. And the nuclear waste treatment cost can be greatly saved, and great economic benefits are achieved.

Description

Technical Field

[0001] The invention relates to a radioactive organic waste liquid distillation device and a distillation method, belonging to the technical field of radioactive waste treatment. Background Art

[0002] The Purex process is commonly used in spent fuel reprocessing to extract uranium and plutonium from components. Tributyl phosphate is used as the extractant and kerosene as the diluent. When a solvent is used for a long time in the Purex process and the extraction performance deteriorates to the point where it cannot meet the extraction rate of uranium and plutonium and the purification requirements of fission products, this part of the solvent becomes a waste organic solvent.

[0003] During the extraction process of nuclear fuel reprocessing, TBP-OK solvent produces a variety of degradation products due to radiolysis and hydrolysis, which harms the extraction process. Usually, the waste TBP is further regenerated and recycled. After several cycles of organic solvents, some degradation products cannot be removed by washing and further treatment methods are required. For example, the Karlsruhe Intermediate Plant in Germany stipulates that when the concentration of dodecanoic acid and dodecyl butyl phosphate reaches 5*10 -5 mol / L or more, the solvent needs to be replaced. The more mature process in the post-processing plant now is to use the distillation tower process to treat these waste solvents. Countries such as Germany and France have conducted corresponding research on it and applied it to engineering practice. For example, the Hague plant in France and the six plants in Japan both use distillation towers to further treat the waste solvents. The waste solvent is first evaporated and dehydrated in the dehydration evaporator under reduced pressure (about 5*103Pa), and the solvent dehydration rate reaches 1g / L. The main evaporator adopts parallel flow operation, and the main evaporator can evaporate more than 95% of the solvent, and the amount of residue obtained is less than 5%, and the residue is sent for incineration.

[0004] At present, the distillation tower is used in the reprocessing of spent fuel and the front stage of nuclear fuel cycle at home and abroad, which generally includes large equipment such as feed tank, preheater, flash vaporizer, TBP distillation tower, kerosene distillation tower, condenser cooler, TBP cooler, kerosene heavy fraction cooler, vacuum pump, etc. The distillation tower has the characteristics of large equipment, complex maintenance, low separation efficiency, and requires multiple people to control. The distillation process used in the reprocessing is

[0005] Patent application document CN113571223A discloses a method and device for treating radioactive organic extractants. The device is a fixed two-stage distillation device with a complex structure. It is only suitable for treating a large amount of radioactive waste liquid generated by the production line. For treating a small amount of radioactive waste liquid, the construction cost of the device is too high. CN115116643A discloses a method for treating radioactive TBP / OK organic waste liquid. The method only recovers partially degraded phosphoric acid and butanol in the organic waste liquid, but cannot extract TBP from the organic waste liquid. In addition, in order to achieve the purpose described in the patent, it is necessary to build an organic waste liquid pyrolysis and pyrolysis gas filtration and treatment device. Summary of the invention

[0006] Aiming at the treatment of medium- and low-level radioactive TBP / OK organic waste liquid generated in spent fuel treatment, the present invention proposes a radioactive organic waste liquid distillation device and a distillation method, which can reduce the amount of organic waste liquid that needs to be treated by separating and purifying TBP / OK.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A radioactive organic waste liquid distillation device, comprising a waste liquid storage tank, a liquid delivery pump, a short-range molecular distillation device, a TBP storage tank, a kerosene storage tank, a first cold trap, a second cold trap, a first-stage filter, a second-stage filter, a heating circulator, a low-temperature circulator, a first cold trap residual liquid collection tank, a second cold trap residual liquid collection tank and a vacuum pump;

[0009] The waste liquid outlet of the waste liquid storage tank is connected to the waste liquid inlet of the short-range molecular distillation device through an infusion pipeline and a liquid delivery pump; the heating medium inlet of the short-range molecular distillation device is connected to the heating medium outlet of the heating circulator, and the heating medium outlet of the short-range molecular distillation device is connected to the heating medium inlet of the heating circulator;

[0010] The TBP outlet of the short-range molecular distillation device is connected to the inlet of the TBP storage tank;

[0011] The kerosene outlet of the short-range molecular distillation device is connected to the inlet of the kerosene storage tank;

[0012] The vacuum port of the short-range molecular distillation device is provided with a vacuum pipeline, and the vacuum pipeline is provided with a first cold trap, a second cold trap, a vacuum gauge, a first-stage filter, a second-stage filter and a vacuum pump in sequence from front to back;

[0013] The cooling medium outlet of the low temperature circulator is connected to the cooling medium inlet of the short-range molecular distillation device and the cooling medium inlet of the first cold trap; the cooling medium inlet of the low temperature circulator is connected to the cooling medium outlet of the short-range molecular distillation device and the cooling medium outlet of the second cold trap; the cooling medium outlet of the first cold trap is connected to the cooling medium inlet of the second cold trap;

[0014] The bottoms of the first cold trap and the second cold trap are both provided with medium outlets communicated with the vacuum pipeline, and are respectively connected to the medium inlets of the second cold trap residual liquid collection tank and the first cold trap residual liquid collection tank.

[0015] In an optional embodiment of the present invention, radiation detection systems and video monitoring systems are installed in the areas where the TBP storage tanks and kerosene storage tanks are located.

[0016] In an optional embodiment of the present invention, a 60-200 mesh filter screen is provided in the waste liquid storage tank, and the filter screen is located between the feed port and the discharge port of the waste liquid storage tank.

[0017] In an optional embodiment of the present invention, the liquid delivery pump is an explosion-proof variable frequency gear pump.

[0018] In an optional embodiment of the present invention, the TBP outlet of the short-range molecular distillation device and the inlet of the TBP storage tank, as well as the kerosene outlet of the short-range molecular distillation device and the inlet of the kerosene storage tank are connected by pipelines with peep windows and vacuum valves.

[0019] In an optional embodiment of the present invention, the vacuum pump is a screw-type explosion-proof vacuum pump.

[0020] In an optional embodiment of the present invention, the heating temperature range of the heating circulator is 50°C to 180°C.

[0021] In an optional embodiment of the present invention, the refrigeration temperature range of the low temperature circulator is -55°C to room temperature.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention can realize the thermal separation of medium and low-level organic waste liquid TBP / OK under low pressure. Compared with the existing TBP / OK distillation extraction technology, the distillation reaction temperature adopted by the present invention is lower, which is very suitable for the distillation of heat-sensitive and high-boiling-point liquids such as TBP / OK organic waste liquid.

[0024] Compared with the extraction process system of chemical plants, the present invention simplifies the large-scale process equipment that originally required a multi-stage distillation tower device to separate TBP from kerosene into a single small short-range molecular distillation device to achieve distillation concentration, separation and recovery functions. The equipment is simple, easy to move, small footprint, reduced process control points, system pressure does not exceed 5kpa, safety is improved, and operation is simple. The device integrates a radiation detection system and a video monitoring system to facilitate analysis of the equipment operation status.

[0025] The present invention can purify TBP in a TBP / OK organic solvent with a TBP purity of 20% to more than 80%, and realize the separation of TBP and kerosene, wherein the TBP content in the kerosene is less than 0.2%, and the separated kerosene can be recycled and reused. Under the same separation requirements, the scheme provided by the present invention can save about 90% of the energy consumption of the TBP / OK extraction process system compared with the existing process technology under the condition of achieving the same separation effect, and the one-time separation does not require multi-stage distillation, and the operation is safe, the degree of automation is high, and the operation can be moved, which simplifies the spent fuel post-processing distillation process, can greatly save the cost of nuclear waste treatment and disposal, and has great economic benefits.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the embodiments of the present invention are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a process control diagram of the system of the present invention;

[0029] Figure 2 It is a longitudinal front view structural schematic diagram of the system of the present invention;

[0030] Figure 3 It is a schematic diagram of the top view of the structure of the system of the present invention;

[0031] In the figure: 1-waste liquid storage tank, 2-liquid delivery pump, 3-short-range molecular distillation equipment, 4-TBP storage tank, 5-kerosene storage tank, 6-first cold trap, 7-second cold trap, 8-first stage filter, 9-second stage filter, 10-heating circulator, 11-low temperature circulator, 12-first cold trap residual liquid collection tank; 13-second cold trap residual liquid collection tank; 14-vacuum pump; 15-radiation detection system; 16-video monitoring system. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0033] Example 1

[0034] Please refer to Figure 1 , Figure 2 and Figure 3 The present embodiment provides a radioactive organic waste liquid distillation device, including a waste liquid storage tank 1, a liquid delivery pump 2, a short-range molecular distillation device 3, a TBP storage tank 4, a kerosene storage tank 5, a first cold trap 6, a second cold trap 7, a first-stage filter 8, a second-stage filter 9, a heating circulator 10, a low-temperature circulator 11, a first cold trap residual liquid collection tank 12, a second cold trap residual liquid collection tank 13, a vacuum pump 14, a radiation detection system 15 and a video monitoring system 16.

[0035] The waste liquid storage tank 1 is a waste liquid raw water tank made of stainless steel with a storage capacity of 30L. It is equipped with a filter screen and a heating tank inside to filter impurities in the waste liquid and continue to preheat the waste liquid. The heating temperature range is 30-60°C to ensure the fluidity of the organic waste liquid. A vacuum valve and a liquid delivery pump 2 are provided on the outlet side of the waste liquid storage tank 1. The liquid delivery pump 2 uses a 0.2kw variable frequency drive motor. The flow rate at the pump outlet is set to 16.2L / h. Through the outlet pipeline at the bottom of the waste liquid storage tank 1 and the liquid delivery pump 2, the short-range molecular distillation equipment 3 is stably supplied.

[0036] In this embodiment, the evaporation area of ​​the selected short-range molecular distillation device 3 is 0.3m 2 The rotor speed is controlled at 250r / min, and the heat exchange area of ​​the built-in condenser is 0.55m 2 , the condensing medium uses low-temperature alcohol, and the low-temperature circulator 11 provides a refrigeration source. The interior of the evaporation chamber of the short-range molecular distillation equipment 3 is provided with a heat source by the heating circulator 10, and the heating medium uses thermal oil, and a circulating heating method is adopted. The TBP discharge pipeline at the lower part of the left side wall of the shell of the short-range molecular distillation equipment 3 is connected to the TBP storage tank 4, and the kerosene discharge pipeline in the middle of the bottom of the short-range molecular distillation equipment 3 is connected to the kerosene storage tank 5. Open the vacuum valve on the pipeline, and observe the outflow of the two separated liquids of TBP and kerosene through the peep window on the pipeline. The air outlet on the right side wall of the short-range molecular distillation equipment 3 is connected to the vacuum pipeline.

[0037] After separation, the TBP liquid flows into the TBP storage tank 4 through the pipeline through the short-range molecular distillation device 3, and the kerosene liquid flows into the kerosene storage tank 5 through the pipeline. The storage tank capacity is 15 L. The TBP storage tank 4 is located obliquely below the short-range molecular distillation device 3, and the kerosene storage tank 5 is located directly below the short-range molecular distillation device 3.

[0038] The short-range molecular distillation device 3 is vacuumed through a 4KW vacuum pump 14 via a vacuum line to make the interior of the short-range molecular distillation device 3 reach a vacuum condition. The vacuum line is provided with a first cold trap 6 and a second cold trap 7, and the heat exchange area of ​​the two cold traps is set to 0.55m 2 The first cold trap 6 is used as the primary cooling device for the exhaust gas, and the second cold trap 7 is used as the gas cooling device at the outlet of the first cold trap 6. The -15°C low-temperature alcohol coolant is used as the cooling medium to cool and collect a small amount of light medium that cannot be collected by the built-in condenser of the short-range molecular distillation device 3. Observe the vacuum gauge set on the vacuum line, and adjust the valve set on the vacuum line as needed to make the internal vacuum degree of the short-range molecular distillation device 3 meet the requirements.

[0039] Vacuum valves are provided at the cooling medium outlets of the first cold trap and the second cold trap. The lower parts of the first cold trap 6 and the second cold trap 7 are connected to the second cold trap residual liquid collecting tank 13 and the first cold trap residual liquid collecting tank 12, respectively. The vacuum valves between the first cold trap 6 and the second cold trap residual liquid collecting tank 13, and between the second cold trap 7 and the first cold trap residual liquid collecting tank 12 are opened to receive a small amount of condensed light medium that cannot be collected by the short-range molecular distillation device 3. The second cold trap residual liquid collecting tank 13 and the first cold trap residual liquid collecting tank 12 are located directly below the first cold trap 6 and the second cold trap 7, respectively.

[0040] After condensation, the exhaust gas in the short-range molecular distillation device 3 is filtered through the first filter 8 arranged in the vacuum pipeline, and then filtered through the second filter 9. After the test is up to standard, it can be discharged. The first filter 8 is used as a primary filter to filter particulate impurities and a small amount of oil droplets in the gas, and the second filter 9 is used to remove radioactive substances in the gas so that the gas meets the discharge requirements.

[0041] The organic waste liquid was treated with TBP / OK organic waste solvent containing 67% components, and 4.23 kg of waste liquid was taken for test verification.

[0042] The connecting pipelines are made of 316L stainless steel, and other pipelines are made of 304 stainless steel.

[0043] The heating power of the thermal oil heater of the heating circulator 10 is 10KW, which is used to provide a heat source for the short-range molecular distillation device 3, with a temperature control of 150°C, a flow rate of 35L / min, and a head of 2.5bar.

[0044] The refrigeration unit of the low-temperature circulator 11 provides cooling medium (high-purity alcohol) for the first cold trap 6, the second cold trap 7 and the built-in condenser of the short-range molecular distillation equipment 3. The temperature is controlled at -20°C, the heat dissipation method is forced air cooling, the circulation volume is 35L / min, and the head is 1.5bar.

[0045] The distillation method of the radioactive organic waste liquid distillation device described in this embodiment includes:

[0046] Feed flow control: Start the liquid feed pump 2. A vacuum valve is provided on the outlet side of the waste liquid storage tank 1. Open the vacuum valve and control the liquid feed pump 2 through frequency conversion regulation. In the waste liquid storage tank 1, the waste liquid is filtered out of particulate impurities by the filter screen, and the waste liquid storage tank 1 is preheated by the heating tank to improve the fluidity of the waste liquid and the evaporation rate after entering the molecular distillation.

[0047] Film-forming mode and speed control of the short-range molecular distillation equipment 3: The short-range molecular distillation equipment 3 adopts a scraping film evaporation process. The short-range molecular film-forming mode and speed control control control the scraping film motor speed at 100-450r / min, so that the feed liquid is continuously and evenly distributed on the heating surface of the short-range molecular distillation equipment 3. The scraper of the short-range molecular distillation equipment 3 scrapes the waste liquid into an extremely thin, turbulent liquid film.

[0048] Temperature control: The heating temperature of the short-range molecular distillation device 3 is controlled by adjusting the temperature, flow rate and pressure of the heating medium, and the condensation temperature is controlled by adjusting the temperature, flow rate and pressure of the cooling medium. The distillation temperature is based on the organic waste liquid just being able to maintain thermal stability; the temperature difference between the hot and cold sides in the short-range molecular distillation device 3 is maintained at 130°C.

[0049] Vacuum degree control: The vacuum degree in the short-range molecular distillation equipment 3 is controlled by adjusting the opening of the exhaust valve on the vacuum exhaust pipeline, and the vacuum degree is set to 5000 Pa.

[0050] Exhaust gas purification control: A small amount of light molecules are contained in the exhaust gas by vacuum extraction. By controlling the temperature of the cooling medium in the first cold trap 6 and the second cold trap 7, the exhaust gas is collected by two-stage condensation. The gas after the two-stage condensation passes through the first-stage filter and the second-stage filter for radioactive nuclide purification and treatment, and finally the exhaust gas is discharged.

[0051] Radiation detection control: TBP storage tank 4 and kerosene storage tank 5 are each provided with a gamma radiation detection system 15. When the components in the waste liquid change, the gamma radiation field will also change, which is used to detect the stability of the discharge of the device.

[0052] Video monitoring control: The system operation stability is observed through the video monitoring system 16.

[0053] Example 2

[0054] Please refer to Figure 1 , Figure 2 and Figure 3 The present embodiment provides a radioactive organic waste liquid distillation device, including a waste liquid storage tank 1, a liquid delivery pump 2, a short-range molecular distillation device 3, a TBP storage tank 4, a kerosene storage tank 5, a first cold trap 6, a second cold trap 7, a first-stage filter 8, a second-stage filter 9, a heating circulator 10, a low-temperature circulator 11, a first cold trap residual liquid collection tank 12, a second cold trap residual liquid collection tank 13, a vacuum pump 14, a radiation detection system 15 and a video monitoring system 16.

[0055] The waste liquid storage tank 1 is a waste liquid raw water tank made of stainless steel with a storage capacity of 30L. It is equipped with a filter screen and a heating tank inside to filter impurities in the waste liquid and continue to preheat the waste liquid. The heating temperature range is 30-60°C to ensure the fluidity of the organic waste liquid. A vacuum valve and a liquid delivery pump 2 are provided on the outlet side of the waste liquid storage tank 1. The liquid delivery pump 2 uses a 0.2kw variable frequency drive motor. The flow rate at the pump outlet is set to 22L / h. Through the outlet pipeline at the bottom of the waste liquid storage tank 1 and the liquid delivery pump 2, the short-range molecular distillation equipment 3 is stably supplied.

[0056] In this embodiment, the evaporation area of ​​the selected short-range molecular distillation device 3 is 0.3m 2 The rotor speed is controlled at 300r / min, and the heat exchange area of ​​the built-in condenser is 0.55m 2 , the condensing medium uses low-temperature alcohol, and the low-temperature circulator 11 provides a refrigeration source. The interior of the evaporation chamber of the short-range molecular distillation equipment 3 is provided with a heat source by the heating circulator 10, and the heating medium uses thermal oil, and a circulating heating method is adopted. The TBP discharge pipeline at the lower part of the left side wall of the shell of the short-range molecular distillation equipment 3 is connected to the TBP storage tank 4, and the kerosene discharge pipeline in the middle of the bottom of the short-range molecular distillation equipment 3 is connected to the kerosene storage tank 5. Open the vacuum valve on the pipeline, and observe the outflow of the two separated liquids of TBP and kerosene through the peep window on the pipeline. The air outlet on the right side wall of the short-range molecular distillation equipment 3 is connected to the vacuum pipeline.

[0057] After separation, the TBP liquid flows into the TBP storage tank 4 through the pipeline through the short-range molecular distillation device 3, and the kerosene liquid flows into the kerosene storage tank 5 through the pipeline. The storage tank capacity is 15 L. The TBP storage tank 4 is located obliquely below the short-range molecular distillation device 3, and the kerosene storage tank 5 is located directly below the short-range molecular distillation device 3.

[0058] The short-range molecular distillation device 3 is vacuumed through a 4KW vacuum pump 14 via a vacuum line to make the interior of the short-range molecular distillation device 3 reach a vacuum condition. The vacuum line is provided with a first cold trap 6 and a second cold trap 7, and the heat exchange area of ​​the two cold traps is set to 0.55m 2The first cold trap 6 is used as the primary cooling device for the exhaust gas, and the second cold trap 7 is used as the gas cooling device at the outlet of the first cold trap 6. It uses -15℃ low-temperature liquid nitrogen coolant as the cooling medium to cool and collect a small amount of light medium that cannot be collected by the built-in condenser of the short-range molecular distillation device 3. Observe the vacuum gauge set on the vacuum line, and adjust the valve set on the vacuum line as needed to make the internal vacuum degree of the short-range molecular distillation device 3 meet the requirements.

[0059] Vacuum valves are provided at the cooling medium outlets of the first cold trap and the second cold trap. The lower parts of the first cold trap 6 and the second cold trap 7 are connected to the second cold trap residual liquid collecting tank 13 and the first cold trap residual liquid collecting tank 12, respectively. The vacuum valves between the first cold trap 6 and the second cold trap residual liquid collecting tank 13, and between the second cold trap 7 and the first cold trap residual liquid collecting tank 12 are opened to receive a small amount of condensed light medium that cannot be collected by the short-range molecular distillation device 3. The second cold trap residual liquid collecting tank 13 and the first cold trap residual liquid collecting tank 12 are located directly below the first cold trap 6 and the second cold trap 7, respectively.

[0060] After condensation, the exhaust gas in the short-range molecular distillation device 3 is filtered through the first filter 8 arranged in the vacuum pipeline, and then filtered through the second filter 9. After the test is up to standard, it can be discharged. The first filter 8 is used as a primary filter to filter particulate impurities and a small amount of oil droplets in the gas, and the second filter 9 is used to remove radioactive substances in the gas so that the gas meets the discharge requirements.

[0061] The organic waste liquid was treated with TBP / OK organic waste solvent containing 33.4% components, and 5.09 kg of waste liquid was taken for test verification.

[0062] The connecting pipelines are made of 316L stainless steel, and other pipelines are made of 304 stainless steel.

[0063] The heating power of the thermal oil heater of the heating circulator 10 is 10KW, which is used to provide a heat source for the short-range molecular distillation device 3, with a temperature control of 110°C, a flow rate of 35L / min, and a head of 2.5bar.

[0064] The refrigeration unit of the low temperature circulator 11 provides cooling medium for the first cold trap 6, the second cold trap 7 and the built-in condenser of the short-range molecular distillation device 3. The temperature is controlled at -10°C, the heat dissipation method is forced air cooling, the circulation volume is 35L / min, and the head is 1.5bar.

[0065] The distillation method of the radioactive organic waste liquid distillation device described in this embodiment includes:

[0066] Feed flow control: Start the liquid feed pump 2. A vacuum valve is provided on the outlet side of the waste liquid storage tank 1. Open the vacuum valve and control the liquid feed pump 2 through frequency conversion regulation. In the waste liquid storage tank 1, the waste liquid is filtered out of particulate impurities by the filter screen, and the waste liquid storage tank 1 is preheated by the heating tank to improve the fluidity of the waste liquid and the evaporation rate after entering the molecular distillation.

[0067] Film-forming mode and speed control of the short-range molecular distillation equipment 3: The short-range molecular distillation equipment 3 adopts a scraping film evaporation process. The short-range molecular film-forming mode and speed control control control the scraping film motor speed at 100-450r / min, so that the feed liquid is continuously and evenly distributed on the heating surface of the short-range molecular distillation equipment 3. The scraper of the short-range molecular distillation equipment 3 scrapes the waste liquid into an extremely thin, turbulent liquid film.

[0068] Temperature control: The heating temperature of the short-range molecular distillation device 3 is controlled by adjusting the temperature, flow rate and pressure of the heating medium, and the condensation temperature is controlled by adjusting the temperature, flow rate and pressure of the cooling medium. The distillation temperature is based on the organic waste liquid just being able to maintain thermal stability; the temperature difference between the hot and cold sides in the short-range molecular distillation device 3 is maintained at 100°C.

[0069] Vacuum degree control: The vacuum degree in the short-range molecular distillation equipment 3 is controlled by adjusting the opening of the exhaust valve on the vacuum exhaust pipeline, and the vacuum degree is set to 1700 Pa.

[0070] Exhaust gas purification control: A small amount of light molecules are contained in the exhaust gas by vacuum extraction. By controlling the temperature of the cooling medium in the first cold trap 6 and the second cold trap 7, the exhaust gas is collected by two-stage condensation. The gas after the two-stage condensation passes through the first-stage filter and the second-stage filter for radioactive nuclide purification and treatment, and finally the exhaust gas is discharged.

[0071] Radiation detection control: TBP storage tank 4 and kerosene storage tank 5 are each provided with a gamma radiation detection system 15. When the components in the waste liquid change, the gamma radiation field will also change, which is used to detect the stability of the discharge of the device.

[0072] Video monitoring control: The system operation stability is observed through the video monitoring system 16.

[0073] The following is a comparison of the test results of Example 1 and Example 2:

[0074] Comparison of experimental results

[0075]

[0076] The test results show that for TBP / OK waste liquid with different component ratios, TBP and kerosene can be further separated and purified. The TBP content after concentration can reach more than 80%, and the TBP content in kerosene is less than 0.15%. The TBP / OK distillation rate can reach 35L / h.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radioactive organic waste liquid distillation device, characterized in that: It includes a waste liquid storage tank, a liquid delivery pump, a short-range molecular distillation device, a TBP storage tank, a kerosene storage tank, a first cold trap, a second cold trap, a first-stage filter, a second-stage filter, a heating circulator, a low-temperature circulator, a first cold trap residual liquid collection tank, a second cold trap residual liquid collection tank and a vacuum pump; The waste liquid outlet of the waste liquid storage tank is connected to the waste liquid inlet of the short-range molecular distillation device through an infusion pipeline and a liquid delivery pump; the heating medium inlet of the short-range molecular distillation device is connected to the heating medium outlet of the heating circulator, and the heating medium outlet of the short-range molecular distillation device is connected to the heating medium inlet of the heating circulator; The TBP outlet of the short-range molecular distillation device is connected to the inlet of the TBP storage tank; The kerosene outlet of the short-range molecular distillation device is connected to the inlet of the kerosene storage tank; The vacuum port of the short-range molecular distillation device is provided with a vacuum pipeline, and the vacuum pipeline is provided with a first cold trap, a second cold trap, a vacuum gauge, a first-stage filter, a second-stage filter and a vacuum pump in sequence from front to back; The cooling medium outlet of the low temperature circulator is connected to the cooling medium inlet of the short-range molecular distillation device and the cooling medium inlet of the first cold trap; the cooling medium inlet of the low temperature circulator is connected to the cooling medium outlet of the short-range molecular distillation device and the cooling medium outlet of the second cold trap; the cooling medium outlet of the first cold trap is connected to the cooling medium inlet of the second cold trap; The bottoms of the first cold trap and the second cold trap are both provided with medium outlets communicated with the vacuum pipeline and are respectively connected to the medium inlets of the second cold trap residual liquid collecting tank and the first cold trap residual liquid collecting tank.

2. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: Radiation detection systems and video monitoring systems are installed in the areas where the TBP storage tanks and kerosene storage tanks are located.

3. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: A 60-200 mesh filter screen is arranged in the waste liquid storage tank, and the filter screen is located between the feed port and the discharge port of the waste liquid storage tank.

4. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: The liquid delivery pump is an explosion-proof variable frequency gear pump.

5. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: The TBP outlet of the short-range molecular distillation device and the inlet of the TBP storage tank, as well as the kerosene outlet of the short-range molecular distillation device and the inlet of the kerosene storage tank are connected via pipelines with peep windows and vacuum valves.

6. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: The vacuum pump is a screw-type explosion-proof vacuum pump.

7. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: The heating temperature range of the heating circulator is 50°C to 180°C.

8. The radioactive organic waste liquid distillation device according to claim 1, characterized in that: The refrigeration temperature range of the low temperature circulator is -55°C to room temperature.

9. A distillation method, characterized in that: The distillation method adopts the radioactive organic waste liquid distillation device described in any one of claims 1 to 7 to carry out distillation treatment on the radioactive organic waste liquid.

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