Radioactive waste molten flue gas purification and recovery system and method

Abstract

This invention discloses a system and method for purifying and recycling radioactive waste molten flue gas. The system comprises a ceramic filtration purification unit, a flue gas cooling unit, a high-efficiency filtration unit, a pressurized storage unit, a repurification unit, and a carrier gas storage tank connected in sequence. The ceramic filtration purification unit captures dust in the flue gas; the flue gas cooling unit cools the flue gas; the high-efficiency filtration unit filters the cooled flue gas; the pressurized storage unit receives and stores the flue gas output from the high-efficiency filtration unit; the repurification unit performs deep purification of the flue gas and sends it to the carrier gas storage tank; the carrier gas storage tank sends the purified flue gas into a plasma torch for reuse. This invention, through the coordinated connection of the ceramic filtration purification unit, flue gas cooling unit, high-efficiency filtration unit, pressurized storage unit, and repurification unit, achieves thorough purification of radioactive flue gas while minimizing waste, thereby realizing the recycling of the flue gas.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment technology, and in particular to a system and method for purifying and recycling radioactive waste molten flue gas. Background Technology

[0002] Nuclear energy is a globally recognized green energy source. Developing nuclear energy can reduce the use of fossil fuels and decrease carbon and pollutant emissions. However, nuclear power plants generate radioactive waste during operation. Currently, nuclear power plants and nuclear-containing facilities typically use technologies such as cement solidification, cement fixation, and supercompression to handle radioactive waste generated during operation and decommissioning. However, these technologies have relatively limited volume reduction effects on radioactive waste and may even lead to volume increase. High-temperature melting technology, on the other hand, can achieve maximum volume reduction of waste and is widely used in the field of hazardous waste treatment, including in the nuclear power sector, and is particularly suitable for the treatment of non-combustible radioactive waste.

[0003] Plasma high-temperature melting technology is a novel technology that has emerged in recent years. The plasma torch generates ultra-high temperatures and highly reactive plasma, making it a research hotspot both domestically and internationally. However, plasma high-temperature melting flue gas is characterized by small volume and high pollutant concentration. The flue gas contains a large amount of radioactive nuclides, acidic gases, and particulate dust, requiring purification to meet emission standards before discharge. Current flue gas purification technologies have the following problems: First, wet processes are used to remove acidic gases from the flue gas, employing alkaline spraying to adsorb HCl, NOx, SO2, and other acidic gases through chemical reactions. While this process has high acid gas removal efficiency, the use of alkaline spraying generates secondary radioactive waste liquid, failing to meet the principle of waste minimization. Second, during system operation, radioactive gases are purified through the flue gas system and then released into the atmosphere. However, if the flue gas system fails, there is a risk of radioactive material leakage and personnel exposure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a system and method for purifying and recycling radioactive waste molten flue gas based on the principle of minimizing waste.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to provide a radioactive waste melting flue gas purification and recycling system, including a ceramic filter purification unit, a flue gas cooling unit, a high-efficiency filter unit, a pressurized storage unit, a re-purification unit and a carrier gas storage tank.

[0006] The ceramic filtration and purification unit is connected to the flue gas outlet of the plasma melting furnace through a first flue gas duct, receives the flue gas discharged from the plasma melting furnace and captures the dust in the flue gas; the first flue gas duct is provided with an air inlet for introducing gas to mix and cool the flue gas in the first flue gas duct.

[0007] The flue gas cooling unit is connected to the ceramic filtration and purification unit to cool and reduce the temperature of the flue gas output from the ceramic filtration and purification unit; the high-efficiency filtration unit filters the cooled flue gas to remove acidic gases, radioactive nuclides, heavy metals and dust; the pressurized storage unit receives and stores the flue gas output from the high-efficiency filtration unit.

[0008] The re-purification unit performs deep purification treatment on the flue gas output from the pressurized storage unit, and transports the flue gas to the carrier gas storage tank through the second flue gas pipeline.

[0009] The carrier gas storage tank is used to connect to the plasma torch of the plasma melting furnace and to send the purified flue gas into the plasma torch for reuse.

[0010] Preferably, the radioactive waste melting flue gas purification and recycling system further includes a gas supply pipeline;

[0011] The gas delivery pipeline connects the inlet of the carrier gas storage tank and the first flue gas pipeline, and sends part of the flue gas stored in the carrier gas storage tank as a mixing gas into the first flue gas pipeline to mix and cool the flue gas.

[0012] Preferably, the inlet side of the ceramic filter purification unit is also provided with a dosing port for injecting quicklime and / or an ammonia source; quicklime is injected into the flue gas through the dosing port for dry pre-acidification; ammonia is injected into the flue gas through the dosing port so that it reacts with nitrogen oxides in the flue gas and decomposes into N2 and H2O.

[0013] Preferably, the ceramic filtration and purification unit includes a ceramic filter cartridge;

[0014] The ceramic filter cartridge is equipped with an SCR catalyst to denitrify the flue gas entering it.

[0015] Preferably, the high-efficiency filtration unit includes a high-efficiency filter;

[0016] The high-efficiency filter is provided with an alkaline packing layer, an activated carbon adsorption layer, a high-efficiency filtration layer, and an iodine adsorption layer.

[0017] Preferably, the pressurized storage unit includes a compressor connected to the high-efficiency filtration unit and a flue gas storage tank connected between the compressor and the re-purification unit;

[0018] The compressor pressurizes the flue gas output from the high-efficiency filtration unit and delivers it to the flue gas storage tank.

[0019] Preferably, the re-purification unit includes a dry desulfurizer, a dry denitrifier, and a CO catalytic oxidizer connected in sequence.

[0020] Preferably, the radioactive waste melting flue gas purification and recycling system further includes a chimney connected to the repurification unit; the repurification unit outputs the purified flue gas to the carrier gas storage tank and / or the chimney.

[0021] Preferably, the radioactive waste melting flue gas purification and recycling system further includes a fourth flue gas duct, which is connected between the outlet side of the pressurized storage unit and the second flue gas duct.

[0022] The present invention also provides a method for purifying and recycling radioactive waste molten flue gas, employing the radioactive waste molten flue gas purification and recycling system described in any of the above-mentioned embodiments, the method comprising the following steps:

[0023] S1. The plasma melting furnace discharges the flue gas into the first flue gas duct. The flue gas is mixed and cooled in the first flue gas duct, and the flue gas temperature drops from 1100℃~1400℃ to 300℃~400℃.

[0024] S2. After the flue gas is cooled, it enters the ceramic filtration and purification unit, which captures the dust in the flue gas and then sends it to the flue gas cooling unit after purification.

[0025] S3. The flue gas cooling unit cools the flue gas to 100℃~120℃ and then sends it to the high-efficiency filtration unit;

[0026] S4. The high-efficiency filtration unit filters the cooled flue gas to remove acidic gases, radioactive nuclides, heavy metals and dust from the flue gas, and then transports it to the pressurized storage unit.

[0027] S5. The pressurized storage unit receives and stores the flue gas output from the high-efficiency filter unit.

[0028] S6. The pressurized storage unit discharges the stored flue gas to the re-purification unit in multiple intermittent stages. After desulfurization, denitrification and CO removal treatment in the re-purification unit, the gas is then transported to the carrier gas storage tank.

[0029] After being connected to the plasma torch of the plasma melting furnace, the carrier gas storage tank sends part or all of its stored flue gas into the plasma torch for reuse.

[0030] Preferably, in step S2, before the flue gas enters the ceramic filter purification unit, quicklime is injected into the flue gas to perform dry pre-acidification of the flue gas, removing 40% to 50% of the acidic gases in the flue gas.

[0031] Preferably, in step S2, the ceramic filter purification unit is equipped with an SCR catalyst to denitrify the flue gas entering it, with a denitrification efficiency of 90% or higher.

[0032] Preferably, in step S4, the high-efficiency filtration unit is provided with an alkaline packing layer, an iodine adsorption layer, a high-efficiency filtration layer and an activated carbon adsorption layer, which respectively remove acidic gases, radioactive nuclides, heavy metals and dust from the flue gas.

[0033] Among them, the alkaline packing layer has a removal rate of >85% for acidic gases, the iodine adsorption layer has a removal rate of ≥99.99% for radioactive nuclides, the high-efficiency filter layer has a removal rate of ≥60% for heavy metals, and the activated carbon adsorption layer has a removal rate of ≥99% for dust.

[0034] Preferably, in step S6, the re-purification unit includes a dry desulfurizer, a dry denitrifier, and a CO catalytic oxidizer connected in sequence, with a SOx removal efficiency ≥98%, a NOx removal efficiency ≥70%, and a CO removal efficiency ≥99%.

[0035] Preferably, the carrier gas storage tank is also connected to the first flue gas pipeline through a gas supply pipeline, so that a portion of the stored flue gas is used as a mixing gas and sent into the first flue gas pipeline to mix and cool the flue gas.

[0036] The beneficial effects of this invention are as follows: by connecting and coordinating the ceramic filtration and purification unit, the flue gas cooling unit, the high-efficiency filtration unit, the pressurized storage unit, and the re-purification unit, the radioactive flue gas is fully purified based on the principle of minimizing waste, so as to realize the recycling of the flue gas; after purification, the flue gas can be used as the working carrier gas of the plasma torch, reducing the carrier gas usage requirement and reducing the emission of flue gas, while enabling the radioactive flue gas to achieve closed-loop circulation in the system, reducing the risk of radioactive material leakage. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0038] Figure 1 This is a connection block diagram of a radioactive waste melting flue gas purification and recycling system according to an embodiment of the present invention;

[0039] Figure 2 yes Figure 1 The diagram shows the structure of the system on the transport vehicle. Detailed Implementation

[0040] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0041] The radioactive waste melting flue gas purification and recycling system of the present invention is used to purify the flue gas discharged from the plasma melting furnace for processing radioactive waste, remove acidic gases, radionuclides, etc. from the flue gas, and can return the treated flue gas to the plasma melting furnace as the working carrier gas of the plasma torch of the plasma melting furnace for reuse.

[0042] like Figure 1 As shown, an embodiment of the radioactive waste melting flue gas purification and recycling system of the present invention includes a ceramic filtration purification unit 10, a flue gas cooling unit 20, a high-efficiency filtration unit 30, a pressurized storage unit 40, a re-purification unit 50 and a carrier gas storage tank 60 connected in sequence, and also includes a first flue gas pipe 71 and a second flue gas pipe 72, etc.

[0043] The ceramic filtration and purification unit 10 is connected to the flue gas outlet of the plasma melting furnace 100 via a first flue gas duct 71, receiving the flue gas discharged from the plasma melting furnace 100 and capturing dust in the flue gas. The flue gas cooling unit 20 is connected to the ceramic filtration and purification unit 10, cooling the flue gas output from the ceramic filtration and purification unit 10. The high-efficiency filtration unit 30 filters the cooled flue gas, removing acidic gases, radioactive nuclides, heavy metals, and dust. The pressurized storage unit 40 receives and stores the flue gas output from the high-efficiency filtration unit 30. The re-purification unit 50 performs deep purification on the flue gas output from the pressurized storage unit 40, and transports the flue gas to the carrier gas storage tank 60 via a second flue gas duct 72. The carrier gas storage tank 60 is connected to the plasma torch 110 of the plasma melting furnace 100, and is used to send the purified flue gas into the plasma torch 110 for reuse as the working carrier gas of the plasma torch 110.

[0044] Specifically, the first flue gas duct 71 is connected between the flue gas outlet of the plasma melting furnace 100 and the inlet of the ceramic filter purification unit 10, and is used to transport flue gas from the flue gas outlet of the plasma melting furnace 100 to the ceramic filter purification unit 10.

[0045] The flue gas temperature output from the plasma melting furnace 100 is approximately 1100℃ to 1400℃, therefore it needs to be cooled before being sent into the ceramic filter purification unit 10. Preferably, a mixed-air cooling method is used to cool the flue gas. For this purpose, an air inlet is provided on the first flue gas duct 71 to introduce gas for mixed-air cooling of the flue gas in the first flue gas duct 71. The gas used for mixed-air cooling is preferably the same as the working carrier gas of the plasma moment 110. After mixed-air cooling, the flue gas temperature is reduced to 300℃ to 400℃. The cooled flue gas then enters the ceramic filter purification unit 10.

[0046] The ceramic filtration and purification unit 10 further includes a ceramic filter cartridge. Flue gas enters the ceramic filter cartridge, where dust is captured, achieving dust removal efficiency of 98% or higher. Furthermore, an SCR catalyst can be installed in the ceramic filter cartridge to perform denitrification treatment on the flue gas, achieving a denitrification efficiency of 90% or higher.

[0047] Furthermore, before entering the ceramic filter purification unit 10, the flue gas can undergo dry pre-acidification, which can reduce the acidification burden on subsequent units. Alternatively, a dosing port can be provided on the inlet side of the ceramic filter purification unit 10 (e.g., on the first flue gas duct 71). Quicklime is injected into the flue gas through the dosing port to perform dry pre-acidification, i.e., to initially remove acidic gases from the flue gas. Dry pre-acidification can remove acidic gases such as HCl, SO2, and HF from the flue gas, with a removal rate of 40%–50%. The dust generated after the quicklime is injected is also captured by the ceramic filter cartridge.

[0048] Furthermore, before entering the ceramic filter purification unit 10, ammonia can be sprayed into the flue gas through the dosing port, such as ammonia water or urea, to react with the nitrogen oxides in the flue gas and decompose them into N2 and H2O.

[0049] The dosing ports for quicklime and ammonia can be installed on the inlet side of the ceramic filter purification unit 10 (for example, on the first flue gas duct 71), and are distributed at intervals according to the flue gas flow direction.

[0050] After being treated by the ceramic filter purification unit 10, the temperature of the flue gas is 300℃~350℃. To meet the operating temperature requirements of the high-efficiency filter unit 30, the flue gas is further cooled before being sent into the high-efficiency filter unit 30. For this purpose, a flue gas cooling unit 20 is connected between the outlet of the ceramic filter purification unit 10 and the inlet of the high-efficiency filter unit 30 via a ventilation pipe. After being cooled by the flue gas cooling unit 20, the temperature of the flue gas is 100℃~120℃.

[0051] Alternatively, the flue gas cooling unit 20 can be a shell-and-tube heat exchanger.

[0052] The high-efficiency filter unit 30 further includes a high-efficiency filter. The high-efficiency filter contains an alkaline packing layer, an activated carbon adsorption layer, a high-efficiency filter layer, and an iodine adsorption layer, which can be arranged in upper and lower layers. The inlet of the high-efficiency filter is located at its top, and the outlet is located at its bottom or lower end. Thus, the flue gas entering the high-efficiency filter passes through the alkaline packing layer, activated carbon adsorption layer, high-efficiency filter layer, and iodine adsorption layer sequentially from top to bottom, and finally exits from the outlet of the high-efficiency filter.

[0053] The system comprises several layers: an alkaline packing layer for adsorbing acidic gases from the flue gas, achieving a removal rate of 85% or higher; an activated carbon adsorption layer for adsorbing dust particles, particularly small-diameter dust particles from the ceramic filter purification unit 10, achieving a dust removal rate of ≥99%; a high-efficiency filter layer for adsorbing heavy metals from the flue gas, achieving a heavy metal removal rate of ≥60%; and an iodine adsorption layer for adsorbing radionuclides from the flue gas, achieving a radionuclide removal rate of ≥99.99%.

[0054] The pressurized storage unit 40 can temporarily store and accumulate flue gas, and it is connected between the high-efficiency filter unit 30 and the re-purification unit 50 through a ventilation pipe. The pressurized storage unit 40 may further include a compressor 41 and a flue gas storage tank 42. The compressor 41 is connected between the high-efficiency filter unit 30 and the flue gas storage tank 42, pressurizing the flue gas output from the high-efficiency filter unit 30 and delivering it into the flue gas storage tank 42.

[0055] The re-purification unit 50, connected downstream of the flue gas storage tank 42, is used for deep purification of the flue gas. Specifically, the re-purification unit 50 may include a dry desulfurizer 51, a dry denitrification unit 52, and a CO catalytic oxidizer 53 connected in sequence. The dry desulfurizer 51 removes sulfides, such as SOx, from the flue gas, with a SOx removal efficiency ≥98%. The dry denitrification unit 52 removes nitrogen oxides, such as NOx, from the flue gas, with a NOx removal efficiency ≥70%. The CO catalytic oxidizer 53 removes CO from the flue gas, with a CO removal efficiency ≥99%.

[0056] The carrier gas storage tank 60 is connected to the outlet of the re-purification unit 50 via the second flue gas pipe 72, receiving and storing the deeply purified flue gas output by the re-purification unit 50. This carrier gas storage tank 60 can also serve as the working carrier gas storage tank 60 of the plasma melting furnace 100, connected to the plasma torch 110 of the plasma melting furnace 100 via the third flue gas pipe 73, transporting the purified flue gas therein to the plasma torch 110 of the plasma melting furnace 100 as the working carrier gas of the plasma torch 110.

[0057] Furthermore, the radioactive waste melting flue gas purification and recycling system of the present invention may also include a gas supply pipe 74. The gas supply pipe 74 is connected between the inlet of the carrier gas storage tank 60 and the first flue gas pipe 71, and a portion of the flue gas stored in the carrier gas storage tank 60 is used as mixing gas and sent into the first flue gas pipe 71 to mix and cool the flue gas. Combined with the connection between the carrier gas storage tank 60 and the plasma melting furnace 100, the purified flue gas has multiple reuse functions.

[0058] The radioactive waste melting flue gas purification and recovery system of the present invention may further include a fourth flue gas duct 75. The fourth flue gas duct 75 is connected between the outlet side of the pressurized storage unit 40 and the second flue gas duct 72. When the radionuclides, acid gases, nitrogen oxides, etc. in the flue gas stored in the pressurized storage unit 40 meet the emission or reuse requirements and no further deep purification is required, the flue gas stored in the pressurized storage unit 40 can enter the carrier gas storage tank 60 through the fourth flue gas duct 75 and the second flue gas duct 72, and then be output from the carrier gas storage tank 60 to the gas delivery duct 74 and / or the third flue gas duct 73.

[0059] Furthermore, the radioactive waste melting flue gas purification and recovery system of the present invention may also include a chimney 80. The chimney 80 is connected to the outlet of the re-purification unit 50, so that the re-purification unit 50 can also output its purified flue gas to the chimney 80 for direct discharge.

[0060] The radioactive waste melting flue gas purification and recovery system of the present invention allows the purified flue gas to be directly discharged through the chimney 80 when it is not needed as the working carrier gas of the plasma torch 110. Alternatively, after the purified flue gas is sent to the plasma torch 110 as its working carrier gas and for mixing and cooling, excess flue gas can be directly discharged through the chimney 80.

[0061] In addition, the radioactive waste molten flue gas purification and recycling system of the present invention is convenient to transport as a whole, such as by means of transport vehicles, so as to realize the transfer and use between multiple radioactive waste generation sources.

[0062] Further, refer to Figure 2 The radioactive waste melting flue gas purification and recovery system of the present invention may further include a plasma melting furnace 100 and a transport vehicle 200. The plasma melting furnace 100, ceramic filtration purification unit 10, flue gas cooling unit 20, high-efficiency filtration unit 30, pressurized storage unit 40, re-purification unit 50, carrier gas storage tank 60, chimney 80, and pipelines connecting the various units are loaded on the transport vehicle 200 to form a mobile flue gas purification and recovery system. The transport vehicle 200 enables the transfer and melting of waste from multiple radioactive waste sources.

[0063] The radioactive waste molten flue gas purification and recovery system of the present invention is used for the purification and recovery of radioactive waste molten flue gas. Reference is made to this system. Figure 1 The method for purifying and recycling radioactive waste molten flue gas, implemented through the system of the present invention, may include the following steps:

[0064] S1. The plasma melting furnace 100 discharges the flue gas into the first flue gas duct 71. The flue gas is mixed and cooled in the first flue gas duct 71, so that the temperature of the flue gas drops from 1100℃~1400℃ to 300℃~400℃.

[0065] S2. After the flue gas is cooled, it enters the ceramic filter purification unit 10. The ceramic filter purification unit 10 captures the dust in the flue gas, with a dust removal efficiency of 98% or higher. After purification, it is sent to the flue gas cooling unit 20.

[0066] Before entering the ceramic filter purification unit 10, quicklime is injected into the flue gas through the dosing port set on the first flue gas pipe 71 to perform dry pre-acidification of the flue gas, removing 40% to 50% of the acidic gases in the flue gas, including HCl, SO2, HF, etc.

[0067] In addition, the ceramic filter purification unit 10 may be equipped with an SCR catalyst to denitrify the flue gas entering it, with a denitrification efficiency of 90% or more.

[0068] Dust containing radioactive nuclides in the flue gas is discharged through the ash discharge hole at the bottom of the ceramic filter cartridge.

[0069] S3, the flue gas cooling unit 20 cools the flue gas to 100℃~120℃ and then sends it to the high-efficiency filter unit 30.

[0070] S4. The high-efficiency filtration unit 30 filters the cooled flue gas to remove acidic gases, radioactive nuclides, heavy metals and dust, and then transports it to the pressurized storage unit 40.

[0071] The high-efficiency filter unit 30 is equipped with an alkaline packing layer, an iodine adsorption layer, a high-efficiency filter layer, and an activated carbon adsorption layer, which respectively remove acidic gases, radioactive nuclides, heavy metals, and dust from the flue gas.

[0072] The alkaline packing layer has a removal rate of >85% for acidic gases, the iodine adsorption layer has a removal rate of ≥99.99% for radioactive nuclides, the high-efficiency filter layer has a removal rate of ≥60% for heavy metals, and the activated carbon adsorption layer has a removal rate of ≥99% for dust.

[0073] S5. The pressurized storage unit 40 receives and stores the flue gas output from the high-efficiency filter unit 30.

[0074] The pressurized storage unit 40 may further include a compressor 41 and a flue gas storage tank 42. The compressor 41 is connected between the high-efficiency filter unit 30 and the flue gas storage tank 42, pressurizing the flue gas output from the high-efficiency filter unit 30 and delivering it into the flue gas storage tank 42.

[0075] S6. The pressurized storage unit 40 discharges the stored flue gas to the re-purification unit 50 in multiple intermittent stages. After desulfurization, denitrification and CO removal treatment in the re-purification unit 50, the gas is transported to the carrier gas storage tank 60.

[0076] The flue gas stored in the pressurized storage unit 40 mainly exits from the flue gas storage tank 42 and enters the re-purification unit 50. The re-purification unit 50 performs deep purification treatment on the flue gas. The re-purification unit 50 includes a dry desulfurizer 51, a dry denitrification unit 52, and a CO catalytic oxidizer 53 connected in sequence; the dry desulfurizer 51 is used to remove sulfides, such as SOx, from the flue gas, with a SOx removal efficiency of ≥98%; the dry denitrification unit 52 is used to remove nitrogen oxides, such as NOx, from the flue gas, with a NOx removal efficiency of ≥70%; the CO catalytic oxidizer 53 is used to remove CO from the flue gas, with a CO removal efficiency of ≥99%.

[0077] The carrier gas storage tank 60 is connected between the re-purification unit 50 and the plasma torch 110 of the plasma melting furnace 100 via the second flue gas pipe 72. When the plasma melting furnace 100 is operating, the carrier gas storage tank 60 can send part or all of its stored flue gas into the plasma torch 110 through the third flue gas pipe 73 to be reused as the working carrier gas of the plasma torch 110, thereby reducing the amount of working carrier gas required by the plasma torch 110.

[0078] The carrier gas storage tank 60 is also connected to the first flue gas pipeline 71 through the gas supply pipeline 74, and a portion of the stored flue gas is sent into the first flue gas pipeline 71 as a mixing gas to mix and cool the flue gas.

[0079] The carrier gas storage tank 60 can reduce the emission of flue gas by sending the purified flue gas to the plasma torch 110 and / or the first flue gas duct 71, while enabling the radioactive flue gas to achieve closed-loop circulation in the system and reducing the risk of radioactive material leakage.

[0080] Understandably, the radioactive waste melting flue gas purification and recycling system of the present invention achieves the purification and recycling of radioactive flue gas based on the principle of minimizing waste. More than 99.99% of the radionuclides in the flue gas are removed. When there is no need to provide working carrier gas for the plasma torch 110, the purified flue gas can be directly discharged through the chimney 80.

[0081] The radioactive waste molten flue gas purification and recovery system of the present invention is suitable for use in the transfer between multiple radioactive waste generation sources. When applied to different radioactive waste generation sources, such as... Figure 2 As shown, after being loaded onto the radioactive waste source by the transport vehicle 200 and reaching the target source, the entire system does not need to be transferred off the transport vehicle 200. Instead, it forms a mobile flue gas purification and recovery system with the transport vehicle 200, directly melting the radioactive waste and purifying and recovering the flue gas generated during the process. It is convenient to use, saving equipment investment and floor space for each radioactive waste generating unit, and reducing the amount of secondary waste generated by the decommissioning of the device, thus meeting the principle of waste minimization.

[0082] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A radioactive waste melting off-gas cleaning and recycling system, characterized by, The system comprises a ceramic filter purification unit, a flue gas cooling unit, a high-efficiency filter unit, a pressurized storage unit, a re-purification unit and a carrier gas storage tank. The ceramic filter purification unit is connected with a flue gas outlet of the plasma melting furnace through a first flue gas pipeline, receives flue gas discharged from the plasma melting furnace and captures dust in the flue gas; the first flue gas pipeline is provided with an air inlet for introducing gas to mix and cool the flue gas in the first flue gas pipeline. The flue gas cooling unit is connected with the ceramic filter purification unit and cools the flue gas output by the ceramic filter purification unit; the high-efficiency filter unit filters the cooled flue gas to remove acid gas, radioactive nuclides, heavy metals and dust in the flue gas; the pressurized storage unit receives the flue gas output by the high-efficiency filter unit and stores the flue gas. The re-purification unit deeply purifies the flue gas output by the pressurized storage unit and delivers the flue gas to the carrier gas storage tank through a second flue gas pipeline. The carrier gas storage tank is used to connect a plasma torch of the plasma melting furnace and deliver the purified flue gas to the plasma torch for reuse.

2. The radioactive waste melt off-gas cleanup and recycling system in accordance with claim 1 wherein, The radioactive waste melting flue gas purification recycling system further comprises a gas delivery pipeline; The gas delivery pipeline is connected between the carrier gas storage tank and the air inlet of the first flue gas pipeline, and delivers part of the flue gas stored in the carrier gas storage tank as mixing gas to the first flue gas pipeline to mix and cool the flue gas.

3. The radioactive waste melting off-gas cleaning recycling system according to claim 1, characterized in that, The inlet side of the ceramic filter purification unit is further provided with a dosing port for spraying lime and / or ammonia source; The lime is sprayed into the flue gas through the dosing port to perform dry pre-acid removal; ammonia is sprayed into the flue gas through the dosing port to react with nitrogen oxides in the flue gas to decompose into N2 and H2O.

4. The radioactive waste melting off-gas cleaning and recycling system according to any one of claims 1 to 3, characterized in that, The ceramic filter purification unit comprises a ceramic filter cartridge; The ceramic filter cartridge is provided with an SCR catalyst to perform denitration treatment on the flue gas entering the cartridge.

5. The radioactive waste melting off-gas cleaning and recycling system according to any one of claims 1 to 3, characterized in that, The high-efficiency filter unit comprises a high-efficiency filter; The high-efficiency filter is provided with an alkaline filler layer, an activated carbon adsorption layer, a high-efficiency filter layer and an iodine adsorption layer.

6. The radioactive waste melting off-gas cleaning recycling system according to any one of claims 1 to 3, characterized in that, The pressurized storage unit comprises a compressor connected with the high-efficiency filter unit and a flue gas storage tank connected between the compressor and the re-purification unit; The compressor pressurizes the flue gas output by the high-efficiency filter unit and delivers the flue gas into the flue gas storage tank.

7. The radioactive waste melting off-gas cleaning recycling system according to any one of claims 1 to 3, characterized in that, The re-purification unit comprises a dry desulfurizer, a dry denitration device and a CO catalytic oxidizer connected in sequence.

8. The radioactive waste melt off-gas cleanup and recovery system according to any one of claims 1 to 3, characterized in that, The radioactive waste melting flue gas purification recycling system further comprises a chimney connected with the re-purification unit; the re-purification unit outputs the purified flue gas to the carrier gas storage tank and / or the chimney; and / or The radioactive waste melting flue gas purification recycling system further comprises a fourth flue gas pipeline connected between the outlet side of the pressurized storage unit and the second flue gas pipeline.

9. A method for purifying and recycling a radioactive waste melt vapor, characterized by, The radioactive waste melting flue gas purification recycling system adopts the radioactive waste melting flue gas purification recycling method comprising the following steps: S1, the plasma melting furnace discharges flue gas into a first flue gas pipeline, the flue gas is mixed and cooled in the first flue gas pipeline, and the flue gas temperature is reduced from 1100-1400℃ to 300-400℃; S2, after the flue gas is cooled, it enters a ceramic filtration and purification unit, the ceramic filtration and purification unit captures dust in the flue gas, and after purification, it is sent to a flue gas cooling unit; S3, the flue gas cooling unit cools the flue gas to 100-120℃, and then sends it to a high-efficiency filtration unit; S4, the high-efficiency filtration unit filters the cooled flue gas, removes acid gases, radioactive nuclides, heavy metals and dust in the flue gas, and then sends it to a pressurized storage unit; S5, the pressurized storage unit receives the flue gas output by the high-efficiency filtration unit and stores it; S6, the pressurized storage unit discharges the stored flue gas to a re-purification unit in multiple times and intermittently, removes SOx, NOx and CO through the re-purification unit, and then sends it to a carrier gas storage tank; The carrier gas storage tank connects the plasma torch of the plasma melting furnace, and sends part or all of the stored flue gas to the plasma torch for reuse.

10. The radioactive waste melt, off-gas clean-up, and recycling method, as claimed in claim 9 wherein, In step S2, lime milk is sprayed into the flue gas before it enters the ceramic filtration and purification unit, dry pre-acid removal is performed on the flue gas, and 40-50% of the acid gases in the flue gas are removed.

11. The radioactive waste melt, off-gas clean-up, and recycling method, as claimed in claim 9 wherein, In step S2, the ceramic filtration and purification unit is provided with an SCR catalyst, which removes NOx in the flue gas entering the unit, and the denitration efficiency is 90% or more.

12. The radioactive waste melt, off-gas clean-up, and recycling method, as claimed in claim 9 wherein, In step S4, the high-efficiency filtration unit is provided with an alkaline filler layer, an iodine adsorption layer, a high-efficiency filtration layer and an activated carbon adsorption layer, which respectively remove acid gases, radioactive nuclides, heavy metals and dust in the flue gas; Among them, the removal rate of acid gases by the alkaline filler layer is > 85%, the removal rate of radioactive nuclides by the iodine adsorption layer is ≥ 99.99%, the removal rate of heavy metals by the high-efficiency filtration layer is ≥ 60%, and the removal rate of dust by the activated carbon adsorption layer is ≥ 99%.

13. The radioactive waste melt, off-gas clean-up, and recycling method, as claimed in claim 9 wherein, In step S6, the re-purification unit includes a dry desulfurizer, a dry denitration device and a CO catalytic oxidation device connected in sequence, the removal efficiency of SOx is ≥ 98%, the removal efficiency of NOx is ≥ 70%, and the removal efficiency of CO is ≥ 99%.

14. The method of claim 9 to 13, wherein the method is characterized by, The carrier gas storage tank is also connected to the first flue gas pipeline through a gas supply pipeline, and part of the stored flue gas is sent into the first flue gas pipeline as a mixed air gas to cool and mix the flue gas.

Images