A device and method for removing the pyrolytic carbon layer on the outer layer of coated particles of spent fuel in a drum

Abstract

The present invention discloses a device for removing the outer pyrolytic carbon layer of spent fuel coated particles in a drum type, which relates to the field of nuclear fuel. The device includes: a drum module, a conveyor belt module, a vibrating screening module, a console and a collection box; the vibrating screening module is installed directly above the conveyor belt module, and the two together pass through the drum module. A collection box is installed at the tail end of the conveyor belt module, and the console is located beside the conveyor belt module. The console is electrically connected to the drum module and the vibrating screening module to control their rotation speed or vibration frequency; the vibrating screening module includes: a screening box, and there is an air film formed by high-pressure gas on the inner surface of the screening box, so that the coated particles will not collide with the screening box after entering the screening box; a method for the above device is also disclosed, and the method includes: putting the coated particles into the drum through the feed pipe, the coated particles are lifted by the drum and fall into the screening box with an air film inside, collide with each other to remove the outer pyrolytic carbon layer, and then are sent into the collection box by the conveyor belt.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear fuel, and more particularly, to a device and method for removing the outer pyrolytic carbon layer of drum-type spent fuel coated particles. Background Art

[0002] The coated fuel particles of high-temperature gas-cooled reactor spent fuel adopt a five-layer structure. The first and third layers are high-density pyrolytic carbon layers, the second layer is a silicon carbide layer, the fourth layer is a loose pyrolytic carbon layer, and the center is a nuclear fuel UO2 core. The removal of the coating layer of the spent fuel coated particles is applied at the front end of spent fuel reprocessing, and the outer pyrolytic carbon is the first coating layer to be removed. When removing the outer pyrolytic carbon, it is necessary to prevent the damage of the silicon carbide layer. Otherwise, once the silicon carbide layer is damaged, it is easy to cause the leakage of the inner pyrolytic carbon and the fuel core, resulting in unnecessary pollution.

[0003] Currently, the traditional device for removing the outer pyrolytic carbon is a fluidized bed combustion device, which uses the fluidized bed combustion method for removal. It can remove both the outer pyrolytic carbon and the graphite matrix simultaneously, but it has the problems of high power consumption, generation of CO2, containing radioactive elements, and the need for tail gas treatment, resulting in relatively high treatment costs. At the same time, during the operation and operation of the fluidized bed combustion device, its professional technology is relatively high. Therefore, in the optimization of control means, professional technical personnel are required for operation and guidance. In addition, general mechanical removal methods are likely to damage the silicon carbide layer while removing the outer pyrolytic carbon, and it is not easy to control. Summary of the Invention

[0004] The purpose of the present invention is to propose a device and method for removing the outer pyrolytic carbon layer of drum-type spent fuel coated particles, which realizes the removal of the outer pyrolytic carbon by the mutual collision of the same coated particles.

[0005] The technical solution of the present invention is: to provide a device for removing the outer pyrolytic carbon layer of drum-type spent fuel coated particles, which includes: a drum module, a conveyor belt module, a vibration screening module, a console, and a collection box;

[0006] The vibration screening module is installed directly above the conveyor belt module, and the two together pass through the drum module. The collection box is installed at the end of the conveyor belt module, and the console is located beside the conveyor belt module. The console is electrically connected to the drum module and the vibration screening module to control their rotation speed or vibration frequency;

[0007] The vibration screening module includes: a screening box, and there is an air film formed by high-pressure gas on the inner surface of the screening box, so that the coated particles will not collide with the screening box after entering the screening box.

[0008] In any of the above technical solutions, further, the drum module includes: a drum, a support roller, a front end cover, a rear end cover, an end cover support, a feed pipe, and a vision sensor;

[0009] The supporting roller is placed flat on the ground. The supporting roller and the drum are coaxially installed. The front end cover and the rear end cover are respectively sleeved on the front and rear of the drum. The end cover supports are installed at the bottoms of the front end cover and the rear end cover, and the end cover supports are placed on the ground.

[0010] There are rectangular holes with the same size in the centers of the front end cover and the rear end cover. The conveyor belt module and the vibrating screening module are inserted into the two rectangular holes together. There is also a feed hole below the rectangular hole of the front end cover, and the feed pipe is inserted into the feed hole. The visual sensor is installed inside the rear end cover, and the visual sensor is electrically connected to the console.

[0011] In any of the above technical solutions, further, the conveyor belt module includes: a conveyor belt frame, a conveyor belt, and a conveyor belt motor.

[0012] The four feet of the conveyor belt frame are placed on the ground, and the middle section of the conveyor belt frame passes through the rectangular holes of the front end cover and the rear end cover. The conveyor belt is installed on the upper surface of the middle section of the conveyor belt frame. The conveyor belt motor is placed on one side of the conveyor belt frame, and the conveyor belt motor is electrically connected to the conveyor belt.

[0013] In any of the above technical solutions, further, the vibrating screening module further includes: rollers, a screening frame, a vibrating screening motor, and an eccentric wheel.

[0014] The screening frame is welded above the conveyor belt frame. Four rollers are installed at the four corners of the screening box, and the four rollers are installed on two tracks of the screening frame. The vibrating screening motor is placed on one side of the screening frame, and the eccentric wheel is connected to both the screening box and the vibrating screening motor at the same time. The vibrating screening motor is also electrically connected to the console.

[0015] In any of the above technical solutions, further, the length of the screening box is greater than the axial length of the drum, and the length of the screening frame is greater than the length of the screening box.

[0016] In any of the above technical solutions, further, the inside of the screening box includes: screening holes, high-pressure air inlet holes, high-pressure air inlet pipes, high-pressure air pipelines, high-pressure air outlet holes, and air pressure sensors.

[0017] The top and bottom of the screening box are uncovered, and there is a screening layer inside. Screening holes are regularly distributed on the surface of the screening layer. High-pressure air pipelines are distributed around each screening hole, and high-pressure air outlet holes are regularly distributed on the high-pressure air pipelines.

[0018] A high-pressure air inlet pipe extends from a corner of the screening layer. The high-pressure air inlet pipe communicates with the high-pressure air pipeline, the high-pressure air inlet pipe communicates with the high-pressure air inlet hole located on the side of the screening box, and the outside of the high-pressure air inlet hole is connected to a high-pressure gas cylinder. The air pressure sensor is arranged at the end of the high-pressure air pipeline, the air pressure sensor is electrically connected to the console, and the console is electrically connected to the output valve of the high-pressure gas cylinder.

[0019] In any of the above technical solutions, further, the size of the screening holes is between that of the coated particles and that of the coated particles with the outer pyrolytic carbon removed.

[0020] A method for removing the outer pyrolytic carbon layer of the coated particles of spent fuel in a drum type for any of the above devices is provided, and the method includes:

[0021] S1. Set the rotation speed of the drum and the working frequency of the vibrating screening motor on the console. After the work is stable, put the coated particles into the drum through the feed pipe. The coated particles are lifted by the drum and fall into the screening box.

[0022] S2. The coated particles in the screening box collide with the coated particles just entering the screening box in the screening box, and the outer pyrolytic carbon falls off. The coated particles with the outer pyrolytic carbon completely fallen off and the pyrolytic carbon waste fall onto the conveyor belt through the screening holes.

[0023] S3. The conveyor belt sends the fallen pyrolytic carbon waste and coated particles into the collection box together, and then separates and processes them on other production lines.

[0024] In any of the above technical solutions, further, since the specific gravity of silicon carbide is greater than that of pyrolytic carbon, under the action of high-pressure gas suspension, the part of the coated particle where silicon carbide is exposed will face downward, and the pyrolytic carbon part will continue to be hit and collided by the falling coated particles above.

[0025] The beneficial effects of the present invention are:

[0026] The technical solution in the present invention uses the drum to lift the coated particles to make them collide with each other, and removes the outer pyrolytic carbon. Compared with the current other methods for removing the outer pyrolytic carbon, this method is simple and easy to implement.

[0027] In the preferred implementation manner of the present invention, the design of the screening box in the present invention makes a gas film wrap the inner wall, so as to ensure that the entering wrapped particles do not contact the screening box, ensure that only the outer pyrolytic carbon is removed, and the silicon carbide layer will not be damaged. Description of the Drawings

[0028] The above and additional advantages of the present invention will become obvious and easy to understand when combined with the description of the embodiments in conjunction with the following drawings, wherein:

[0029] Figure 1 is a side view of a drum type device for removing the outer pyrolytic carbon layer of the coated particles of spent fuel according to an embodiment of the present invention;

[0030] Figure 2 is a front view of a drum type device for removing the outer pyrolytic carbon layer of the coated particles of spent fuel according to an embodiment of the present invention;

[0031] Figure 3It is a top view of a device for removing the outer pyrolytic carbon layer of spent fuel coated particles according to an embodiment of the present invention;

[0032] Figure 4 It is along the Figure 3 sectional view taken along the dashed line of a device for removing the outer pyrolytic carbon layer of spent fuel coated particles according to an embodiment of the present invention;

[0033] Figure 5 It is a side view of the screening box of a device for removing the outer pyrolytic carbon layer of spent fuel coated particles according to an embodiment of the present invention;

[0034] Figure 6 It is a top view of the screening box of a device for removing the outer pyrolytic carbon layer of spent fuel coated particles according to an embodiment of the present invention.

[0035] Wherein, 10 - drum module, 11 - drum, 12 - support roller, 13 - front end cover, 14 - rear end cover, 15 - end cover support, 16 - feed pipe, 17 - vision sensor, 20 - conveyor belt module, 21 - conveyor belt frame, 22 - conveyor belt, 23 - conveyor belt motor, 30 - vibrating screening module, 31 - screening box, 311 - screening holes, 312 - high - pressure air inlet holes, 313 - high - pressure air inlet pipe, 314 - high - pressure air pipeline, 315 - high - pressure air outlet holes, 316 - air pressure sensor, 32 - roller, 33 - screening frame, 34 - vibrating screening motor, 35 - eccentric wheel, 40 - control console, 50 - collection box. Detailed implementation manners

[0036] In order to more clearly understand the above - mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0037] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0038] As Figure 1 and Figure 2 shown, this embodiment provides a device for removing the outer pyrolytic carbon layer of spent fuel coated particles, including: a drum module 10, a conveyor belt module 20, a vibrating screening module 30, a control console 40 and a collection box 50.

[0039] The vibration screening module 30 is installed directly above the conveyor belt module 20, and the two together pass through the drum module 10. A collection box 50 is installed at the end of the conveyor belt module 20. The control console 40 is located beside the conveyor belt module 20, and the control console 40 is electrically connected to the drum module 10 and the vibration screening module 30 to control their rotation speeds or vibration frequencies.

[0040] Specifically, as Figure 1 and Figure 4 shown, the drum module 10 includes: a drum 11, a support roller 12, a front end cover 13, a rear end cover 14, an end cover support 15, a feed pipe 16, and a vision sensor 17.

[0041] The support roller 12 is placed flat on the ground and installed coaxially with the drum 11; the front end cover 13 and the rear end cover 14 are respectively sleeved on the front and rear of the drum 11, and the end cover support 15 is installed at the bottoms of the front end cover 13 and the rear end cover 14. The end cover support 15 is placed on the ground, and the front end cover 13, the rear end cover 14, and the end cover support 15 do not rotate with the drum 11; there are rectangular holes of the same size in the centers of the front end cover 13 and the rear end cover 14, and the conveyor belt module 20 and the vibration screening module 30 together pass through the rectangular holes of both; there is also a feed hole below the rectangular hole of the front end cover 13. The inlet of the feed pipe 16 faces upward, and the outlet is inserted into the feed hole of the front end cover 13; the vision sensor 17 is installed on the rear end cover 14 and faces the inside of the drum 11. The vision sensor 17 is electrically connected to the control console 40, and the vision sensor 17 is used to detect the situation of the coated particles inside the drum 11.

[0042] The coated particles are put into the drum 11 from the inlet of the feed pipe 16, and after falling, they are lifted up due to the rotation of the drum 11 and fall on the vibration screening module 30. The coated particles that pass through the screening fall onto the conveyor belt module 20 and finally into the collection box 50.

[0043] As Figure 2 and Figure 3 shown, the conveyor belt module 20 includes: a conveyor belt frame 21, a conveyor belt 22, and a conveyor belt motor 23.

[0044] The four feet of the conveyor belt frame 21 are placed on the ground, and the middle section of the conveyor belt frame 21 passes through the rectangular holes in the centers of the front end cover 13 and the rear end cover 14; the conveyor belt 22 is located on the upper surface of the middle section of the conveyor belt frame 21; the conveyor belt motor 23 is placed on one side of the conveyor belt frame 21, and the conveyor belt motor 23 is electrically connected to the conveyor belt 22 to drive the conveyor belt 22 to work.

[0045] The vibration screening module 30 includes: a screening box 31, rollers 32, a screening frame 33, a vibration screening motor 34, and an eccentric wheel 35.

[0046] The screening frame 33 is welded above the conveyor belt frame 21. Four rollers 32 are installed at the four corners of the screening box 31, and the four rollers 32 are mounted on two tracks of the screening frame 33. The vibrating screening motor 34 is placed on one side of the screening frame 33. The vibrating screening motor 34 is connected to the eccentric wheel 35, and the eccentric wheel 35 is also connected to the screening box 31. The vibrating screening motor 34 drives the eccentric wheel 35 to make the screening box 31 reciprocate on the two tracks of the screening frame 33 at a certain frequency and amplitude.

[0047] Specifically, the length of the screening box 31 is greater than the axial length of the drum 11, the length of the screening frame 33 is greater than the length of the screening box 31, and the two sides of the screening box 31 will not enter the rectangular holes at the centers of the front end cover 13 and the rear end cover 14 during the reciprocating movement. The vibrating screening motor 34 is also electrically connected to the control console 40, and the control console 40 controls the working frequency of the vibrating screening motor 34.

[0048] As Figure 5 and Figure 6 shown, the interior of the screening box 31 includes: screening holes 311, high-pressure air inlet holes 312, high-pressure air inlet pipes 313, high-pressure air pipes 314, high-pressure air outlet holes 315, and air pressure sensors 316.

[0049] The top and bottom of the screening box 31 are uncovered, and there is a screening layer inside. Screening holes 311 are regularly distributed on the surface of the screening layer. High-pressure air pipes 314 are distributed around each screening hole 311, and high-pressure air outlet holes 315 are regularly distributed on the high-pressure air pipes 314. A high-pressure air inlet pipe 313 extends from a corner of the screening layer. The high-pressure air inlet pipe 313 communicates with the high-pressure air pipe 314, and the high-pressure air inlet pipe 313 communicates with the high-pressure air inlet hole 312 on the side of the screening box 31. The outside of the high-pressure air inlet hole 312 is connected to a high-pressure gas cylinder. The air pressure sensor 316 is arranged at the end of the high-pressure air pipe 314. The air pressure sensor 316 is electrically connected to the control console 40, and the air pressure sensor 316 transmits the detected air pressure data to the control console 40, and the control console 40 controls the output valve of the high-pressure gas cylinder.

[0050] Specifically, the size of the screening holes 311 is between the coated particles and the coated particles with the outer pyrolytic carbon removed. There is an air film formed by the continuous jetting of the high-pressure air outlet holes 315 around the screening holes 311, ensuring that the coated particles do not touch the screening box 31, thereby ensuring that the silicon carbide layer of the coated particles is not damaged.

[0051] This embodiment also provides a method for removing the outer pyrolytic carbon layer of the spent fuel coated particles of the drum type. This method is used for the above device, and this method includes:

[0052] S1. Set the rotational speed of the drum 11 and the operating frequency of the vibrating screening motor 34 on the console 40. After the operation stabilizes, feed the coated particles into the drum 11 through the feed pipe 16. The coated particles are lifted by the drum 11 and fall into the screening box 31.

[0053] S2. The coated particles in the screening box 31 collide with the coated particles that have just entered the screening box 31 inside the screening box 31, causing the outer pyrolytic carbon to fall off. The coated particles with the outer pyrolytic carbon completely fallen off and the pyrolytic carbon waste fall onto the conveyor belt 22 through the screening holes 311.

[0054] S3. The conveyor belt 22 sends the fallen pyrolytic carbon waste and coated particles into the collection box 50 together, and then separates and processes them on other production lines.

[0055] Specifically, since the specific gravity of silicon carbide is greater than that of pyrolytic carbon, under the action of high-pressure gas suspension, the part of the coated particle exposing silicon carbide will face downward, and the pyrolytic carbon part will continue to be hit and collided by the falling coated particles above.

[0056] In summary, the present invention proposes a device for removing the outer pyrolytic carbon layer of spent fuel coated particles in a drum type, including: a drum module 10, a conveyor belt module 20, a vibrating screening module 30, a console 40, and a collection box 50.

[0057] The vibrating screening module 30 is installed directly above the conveyor belt module 20, and the two together pass through the drum module 10. The tail end of the conveyor belt module 20 is installed with the collection box 50. The console 40 is located beside the conveyor belt module 20, and the console 40 is electrically connected to the drum module 10 and the vibrating screening module 30 to control their rotational speed or vibration frequency;

[0058] Among them, the vibrating screening module 30 includes: a screening box 31. There is an air film formed by high-pressure gas on the inner surface of the screening box 31, so that the coated particles will not collide with the screening box 31 after entering the screening box 31.

[0059] The present invention also proposes a method for removing the outer pyrolytic carbon layer of spent fuel coated particles in a drum type. This method is applied to the above device. This method includes: starting up. After the drum 11 and the vibrating screening motor 34 operate stably, feed the coated particles into the drum 11 through the feed pipe 16. The coated particles are lifted by the drum 11 and fall into the screening box 31 with an air film inside. The newly fallen coated particles hit the coated particles already inside the screening box 31 to remove the outer pyrolytic carbon, and then fall onto the conveyor belt 22 and are sent into the collection box 50 by the conveyor belt 22.

[0060] In the present invention, terms such as "mounted", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, "connected" may be a fixed connection, a detachable connection, or an integral connection; "joined" may be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The shapes of the various components in the drawings are all schematic, and there is no exclusion of a certain difference from their actual shapes. The drawings are only used to illustrate the principles of the present invention and are not intended to limit the present invention.

[0062] Although the present invention has been disclosed in detail with reference to the drawings, it should be understood that these descriptions are merely exemplary and are not used to limit the application of the present invention. The protection scope of the present invention is defined by the appended claims and may include various modifications, adaptations, and equivalent solutions made to the invention without departing from the protection scope and spirit of the present invention.

Claims

1. A device for removing the outer pyrolytic carbon layer of coated particles of spent fuel in a drum type, characterized in that, The device includes: a drum module (10), a conveyor belt module (20), a vibration screening module (30), a console (40), and a collection box (50); The vibration screening module (30) is installed directly above the conveyor belt module (20), and the two together pass through the drum module (10). The collection box (50) is installed at the end of the conveyor belt module (20). The console (40) is located beside the conveyor belt module (20), and the console (40) is electrically connected to the drum module (10) and the vibration screening module (30) to control their rotation speeds or vibration frequencies; The vibration screening module (30) includes: a screening box (31). There is an air film formed by high-pressure gas on the inner surface of the screening box (31), so that the coated particles will not collide with the screening box (31) after entering the screening box (31); The length of the screening box (31) is greater than the axial length of the drum (11), and the length of the screening frame (33) is greater than the length of the screening box (31). The interior of the screening box (31) includes: screening holes (311), high-pressure air inlet holes (312), high-pressure air inlet pipes (313), high-pressure air pipelines (314), high-pressure air outlet holes (315), and a pressure sensor (316); The top and bottom of the screening box (31) are uncovered, and there is a screening layer inside. The screening holes (311) are regularly distributed on the surface of the screening layer. The high-pressure air pipelines (314) are distributed around each screening hole (311), and the high-pressure air outlet holes (315) are regularly distributed on the high-pressure air pipelines (314); One corner of the screening layer extends out the high-pressure air inlet pipe (313). The high-pressure air inlet pipe (313) communicates with the high-pressure air pipeline (314). The high-pressure air inlet pipe (313) communicates with the high-pressure air inlet hole (312) located on the side of the screening box (31). The outside of the high-pressure air inlet hole (312) is connected to a high-pressure gas cylinder. The pressure sensor (316) is arranged at the end of the high-pressure air pipeline (314). The pressure sensor (316) is electrically connected to the console (40), and the console (40) is electrically connected to the output valve of the high-pressure gas cylinder.

2. The device for removing the outer pyrolytic carbon layer of the coated particles of spent fuel in a drum type as described in claim 1, wherein The drum module (10) includes: a drum (11), support rollers (12), a front end cover (13), a rear end cover (14), end cover supports (15), a feed pipe (16), and a vision sensor (17); The support rollers (12) are placed flat on the ground. The support rollers (12) and the drum (11) are coaxially installed. The front end cover (13) and the rear end cover (14) are respectively sleeved on the front and rear of the drum (11). The end cover supports (15) are installed at the bottoms of the front end cover (13) and the rear end cover (14), and the end cover supports (15) are placed on the ground; The front end cover (13) and the rear end cover (14) have rectangular holes of the same size at their centers. The conveyor belt module (20) and the vibrating screening module (30) are together located in the two rectangular holes. There is also a feed hole below the rectangular hole of the front end cover (13), and the feed pipe (16) is inserted into the feed hole. The vision sensor (17) is installed inside the rear end cover (14), and the vision sensor (17) is electrically connected to the console (40).

3. The apparatus for removing the pyrolytic carbon layer on the outer layer of the spent fuel coated particle of the drum type according to claim 2, wherein The conveyor belt module (20) includes: a conveyor belt frame (21), a conveyor belt (22), and a conveyor belt motor (23). The four feet of the conveyor belt frame (21) are placed on the ground, and the middle section of the conveyor belt frame (21) passes through the rectangular holes of the front end cover (13) and the rear end cover (14). The conveyor belt (22) is installed on the upper surface of the middle section of the conveyor belt frame (21). The conveyor belt motor (23) is placed on one side of the conveyor belt frame (21), and the conveyor belt motor (23) is electrically connected to the conveyor belt (22).

4. The device for removing the outer pyrolytic carbon layer of the spent fuel coated particle as described in claim 3, wherein The vibrating screening module (30) further includes: rollers (32), a screening frame (33), a vibrating screening motor (34), and an eccentric wheel (35). The screening frame (33) is welded above the conveyor belt frame (21). Four rollers (32) are installed at the four corners of the screening box (31), and the four rollers (32) are installed on two tracks of the screening frame (33). The vibrating screening motor (34) is placed on one side of the screening frame (33), and the eccentric wheel (35) is connected to both the screening box (31) and the vibrating screening motor (34) at the same time. The vibrating screening motor (34) is also electrically connected to the console (40).

5. The apparatus for removing the outer pyrolytic carbon layer of the coated particles of spent fuel in a drum type as claimed in claim 4, wherein, The size of the screening holes (311) is between that of the coated particles and that of the coated particles with the outer layer of pyrolytic carbon removed.

6. A method for removing the pyrolytic carbon layer on the outer layer of the spent fuel coated particles of the drum type for the device according to any one of claims 1 to 5, characterized in that, The method includes: S1. Set the rotation speed of the drum and the operating frequency of the vibrating screening motor on the console. After the operation is stable, put the coated particles into the drum through the feed pipe. The coated particles are lifted by the drum and fall into the screening box. S2. The coated particles in the screening box collide with the coated particles just entering the screening box inside the screening box, causing the outer layer of pyrolytic carbon to fall off. The coated particles with the outer layer of pyrolytic carbon completely fallen off and the pyrolytic carbon waste fall onto the conveyor belt through the screening holes. S3. The conveyor belt sends the fallen pyrolytic carbon waste and coated particles into the collection box together, and then they are separated and processed on other production lines.

7. The method for removing the outer pyrolytic carbon layer of the coated particles of spent fuel in a drum type as claimed in claim 6, wherein, Since the specific gravity of silicon carbide is greater than that of pyrolytic carbon, under the action of high-pressure gas suspension, the part of the coated particle exposing silicon carbide will face downward, and the pyrolytic carbon part will continue to be above and be hit by the falling coated particles and collide.

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