Magnetic powder sealing device for nuclear spent fuel reprocessing plant and method for injecting magnetic powder

Abstract

The application discloses a kind of nuclear spent fuel reprocessing equipment magnetic powder sealing device and method, including shell, first pole shoe, second pole shoe, magnetic component and magnetic conducting component, two end surfaces of magnetic conducting component in the axial direction of inner cavity form sealing gap between first pole shoe and second pole shoe respectively.When injecting magnetic powder into sealing gap, make the axial direction of inner cavity parallel with the direction of gravity, and inner cavity opening is upward.Assemble, first pole shoe is assembled in the inner cavity of shell first, the pole tooth of first pole shoe is upward, magnetic powder is injected to the pole tooth of first pole shoe, then magnetic component and magnetic conducting component are assembled in inner cavity, and magnetic powder is injected above magnetic conducting component.After second pole shoe and end cover are assembled in the inner cavity of shell, magnetic powder is uniformly distributed by rotating magnetic conducting component driven by rotating shaft.In the process of assembling, magnetic component is not magnetized or weakly magnetized, finally, magnetic component is energized or magnetized, so that the uniformity of magnetic powder injection and the sealing performance of device can be improved.

Description

Technical Field

[0001] This invention belongs to the field of magnetic powder sealing technology, specifically relating to a magnetic powder sealing device and magnetic powder injection method for a nuclear spent fuel reprocessing equipment. Background Technology

[0002] Spent nuclear fuel is irradiated and used nuclear fuel, typically produced by nuclear reactors in nuclear power plants. It is highly radioactive and toxic, and rich in non-renewable and rare strategic resources such as uranium and plutonium. Sealing its reprocessing equipment is a recognized world-class challenge. A leak not only damages the spent nuclear fuel reprocessing equipment, directly affecting the efficiency of nuclear waste treatment, but also leads to the leakage of radioactive materials during the reprocessing process. These materials include radioactive isotopes such as uranium, plutonium, strontium, and iodine. If leaked into the environment, they would cause irreparable and severe consequences for workers, public health, and the surrounding ecosystem.

[0003] Magnetic powder seals are widely used in various nuclear equipment in the nuclear energy field due to their advantages such as resistance to extreme high and low temperatures, strong pressure resistance, simple structure, high reliability, no pollution, long service life, and the ability to meet sealing requirements in specific environments through surface modification. However, due to the small sealing gap, the responsiveness of magnetic powder as a superparamagnetic material to magnetic fields, and the poor fluidity of magnetic powder as a solid compared to a liquid, when adding magnetic powder to a magnetic powder seal device, the powder will typically adhere to wherever it is injected. The magnetic powder seal structure and injection method in related technologies cannot guarantee that the added magnetic powder can be uniformly adsorbed on the pole teeth to effectively fill the sealing gap. Therefore, a small amount of leakage may occur, failing to achieve zero leakage of the sealed medium, and may even lead to a significant reduction in the pressure resistance of the magnetic powder seal device or complete loss of sealing effect. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a magnetic powder sealing device for nuclear spent fuel reprocessing equipment that improves the uniformity of magnetic powder distribution and sealing performance.

[0006] An embodiment of the present invention provides a magnetic powder injection method.

[0007] The magnetic powder sealing device of the spent nuclear fuel reprocessing equipment according to an embodiment of the present invention includes:

[0008] A housing having an internal cavity, one end of which is used for connection to a spent nuclear fuel reprocessing facility;

[0009] A rotating shaft is disposed in the inner cavity, and the rotating shaft and the inner cavity are arranged coaxially;

[0010] The magnetic powder sealing assembly comprises a first pole shoe, a second pole shoe, a magnetic component and a magnetic conducting component, the first pole shoe and the second pole shoe are arranged along the axial direction of the inner cavity and connected to the inner wall of the shell, a first chamber and a second chamber are formed between the first pole shoe and the second pole shoe, the magnetic component is arranged in the first chamber and two magnetic poles of the magnetic component abut against the first pole shoe and the second pole shoe respectively, the magnetic conducting component is connected to the rotating shaft, and part of the magnetic conducting component is located in the second chamber, so that two end faces of the magnetic conducting component in the axial direction of the inner cavity form a sealing gap with the first pole shoe and the second pole shoe respectively, and the sealing gap is used for filling magnetic powder.

[0011] An end cover is located at one end of the shell away from the nuclear spent fuel reprocessing equipment and is fixedly connected with the shell.

[0012] The magnetic powder sealing device of the nuclear spent fuel reprocessing equipment of the embodiment of the present application is convenient for uniformly injecting magnetic powder during assembly, improves the uniformity of the distribution of the magnetic powder, makes the sealing performance of the magnetic powder sealing structure better, and avoids causing irreparable harm due to leakage of dangerous substances such as nuclear spent fuel.

[0013] In some embodiments, the number of the magnetic powder sealing assemblies is at least two groups.

[0014] In some embodiments, the shell comprises a plurality of segmented shells, the plurality of segmented shells are sequentially connected along the axial direction of the inner cavity, and two adjacent segmented shells are coaxially arranged and fixedly connected, and at least one magnetic powder sealing assembly is arranged between each segmented shell and the rotating shaft.

[0015] In some embodiments, a separation component is arranged between two adjacent groups of the magnetic powder sealing assemblies, and the separation component comprises a magnetic separation ring and / or a gasket.

[0016] In some embodiments, the end cover is positioned with the shell through a shoulder, the end cover abuts against the adjacent magnetic powder sealing assembly, one end of the shell away from the end cover is positioned with the nuclear spent fuel reprocessing equipment through a shoulder, and one end of the shell away from the end cover has a first positioning portion for abutting positioning with the adjacent magnetic powder sealing assembly.

[0017] In some embodiments, the magnetic component is a permanent magnet or an electromagnet.

[0018] In some embodiments, the magnetic component is a permanent magnet or an electromagnet.

[0019] And / or, the first pole shoe and the second pole shoe are provided with a second positioning part, which is used for positioning the magnetic component arranged in the first chamber;

[0020] And / or, the first pole shoe and the second pole shoe have a plurality of pole teeth arranged along the radial direction of the inner cavity, and the magnetic conducting component has a positioning mark corresponding to the pole teeth in the corresponding first pole shoe and / or second pole shoe on the end face in the axial direction of the inner cavity.

[0021] The magnetic powder injection method of the embodiment of the present application is used for injecting magnetic powder into the sealing gap of the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment in any of the above embodiments, and the magnetic powder injection method comprises:

[0022] S1, the shell and the rotating shaft in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment are installed on the nuclear spent fuel reprocessing equipment, and the inner cavity of the shell is open at one end away from the nuclear spent fuel reprocessing equipment, and the opening is directed upward in the direction of gravity;

[0023] S2, the first pole shoe in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment is assembled in the inner cavity of the shell, and magnetic powder is injected into the space above the pole teeth of the first pole shoe to form a plurality of magnetic powder O-rings;

[0024] S3, the magnetic component and the magnetic conducting component in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment are assembled in the inner cavity of the shell, the magnetic component has no magnetism or the magnetic field strength of the magnetic component is less than a first threshold value, and magnetic powder is injected into the position above the magnetic conducting component corresponding to the pole teeth in the second pole shoe to form a plurality of magnetic powder O-rings;

[0025] S4, the second pole shoe in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment is assembled in the inner cavity of the shell;

[0026] S5, the end cover is connected to the shell;

[0027] S6, the rotating shaft is driven to rotate to drive the magnetic conducting component to rotate relative to the first pole shoe and the second pole shoe;

[0028] S7, the magnetic component is energized or magnetized to make the magnetic field strength of the magnetic component reach a second threshold value, wherein the second threshold value is greater than the first threshold value.

[0029] In some embodiments, the number of magnetic powder sealing assemblies in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment is a plurality;

[0030] Before step S5, the following steps are further included:

[0031] Placing the isolation component into the inner cavity of the shell for isolating the assembled second pole shoe from the magnetic powder sealing assembly located above it, repeating steps S2 to S4 to complete the assembly of the next magnetic powder sealing assembly and the injection of the magnetic powder;

[0032] Repeating the previous step until the assembly of all magnetic powder sealing assemblies and the injection of the magnetic powder are completed.

[0033] In some embodiments, the width of the magnetic powder O-ring is 0.2mm to 0.4mm, and the height of the magnetic powder O-ring is 0.1mm to 0.2mm.

[0034] In some embodiments, in step S6, the rotation speed of the rotating shaft is 0.05r / s to 1r / s, and the rotating shaft rotates 1 to 5 rounds. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a schematic diagram of a magnetic powder sealing device of a spent nuclear fuel reprocessing equipment according to an embodiment of the present application.

[0036] Figure 2 is a schematic diagram of a magnetic powder sealing device of a spent nuclear fuel reprocessing equipment according to another embodiment of the present application.

[0037] Figure 3 is a schematic diagram of a magnetic powder sealing device of a spent nuclear fuel reprocessing equipment according to yet another embodiment of the present application.

[0038] Figure 4 is a schematic diagram of a spent nuclear fuel reprocessing equipment according to an embodiment of the present application in a state of injecting magnetic powder on a first pole shoe.

[0039] Figure 5 is Figure 4 a schematic diagram in A-A direction.

[0040] Figure 6 is a flowchart of a magnetic powder injection method according to an embodiment of the present application.

[0041] REFERENCE NUMERALS:

[0042] 1, shell; 11, segmented shell; 12, stop; 13, first positioning part;

[0043] 2, rotating shaft;

[0044] 31, first pole shoe; 32, second pole shoe; 33, magnetic component; 34, magnetic conducting component; 35, sealing member; 36, first chamber; 37, second chamber; 38, second positioning part; 39, pole tooth;

[0045] 4, end cover;

[0046] 51, magnetic isolation ring; 52, gasket;

[0047] 6. Magnetic powder;

[0048] 7. Nuclear spent fuel reprocessing equipment. DETAILED DESCRIPTION

[0049] Embodiments of the present application are described below in detail with reference to the accompanying drawings. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be construed as limiting the present application.

[0050] As Figures 1 to 3 shown in the drawings, the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment of the embodiments of the present application comprises a shell 1, a rotating shaft 2, a magnetic powder sealing assembly and an end cover 4. The magnetic powder sealing device of the nuclear spent fuel reprocessing equipment of the embodiments of the present application can be applied to the reprocessing equipment of nuclear spent fuel, and is used for sealing substances with high risk level to avoid leakage.

[0051] The shell 1 has an inner cavity, and one end of the shell 1 is used for connecting with the nuclear spent fuel reprocessing equipment 7. The rotating shaft 2 is arranged in the inner cavity, and the rotating shaft 2 and the inner cavity are coaxially arranged. The rotating shaft 2 partially extends out of the outer shell of the nuclear spent fuel reprocessing equipment 7. The shell 1 and the magnetic powder sealing assembly of the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment are used for sealing the part of the nuclear spent fuel reprocessing equipment 7, and the part is sealed without affecting the normal operation of the rotating shaft 2, so that the part does not leak.

[0052] The magnetic powder sealing assembly comprises a first pole shoe 31, a second pole shoe 32, a magnetic component 33 and a magnetic conducting component 34. The first pole shoe 31 and the second pole shoe 32 are arranged along the axial direction of the inner cavity and are connected to the inner wall of the shell 1. After the first pole shoe 31 and the second pole shoe 32 are assembled on the shell 1, the first pole shoe 31 and the second pole shoe 32 are fixed relative to the shell 1, and the first pole shoe 31 and the second pole shoe 32 are sealed from each other, for example, by arranging a sealing ring, an oil seal structure or the like to realize the sealing between the first pole shoe 31 and the shell 1 and the sealing between the second pole shoe 32 and the shell 1. The first pole shoe 31 and the second pole shoe 32 form a first chamber 36 and a second chamber 37 therebetween. The magnetic component 33 is arranged in the first chamber 36, and two magnetic poles of the magnetic component 33 abut against the first pole shoe 31 and the second pole shoe 32, respectively. The magnetic conducting component 34 is connected to the rotating shaft 2, and a part of the magnetic conducting component 34 is located in the second chamber 37, so that two end faces of the magnetic conducting component 34 in the axial direction of the inner cavity form sealing gaps with the first pole shoe 31 and the second pole shoe 32, respectively. The sealing gaps are used for filling magnetic powder. The magnetic component 33 can form a magnetic field at the sealing gaps through the first pole shoe 31 and the second pole shoe 32, so that the magnetic powder is stably gathered at the sealing gaps to form multiple sealing rings. The end cover 4 is located at the end of the shell 1 away from the nuclear spent fuel reprocessing equipment 7 and is fixedly connected to the shell 1, and is used for ensuring the structural stability of the magnetic powder sealing assembly and preventing the magnetic powder sealing assembly from being disturbed by the external environment.

[0053] The magnetic component 33 is a permanent magnet or an electromagnet. Figure 1 The diagram shows the structure of the magnetic component 33, which is an electromagnet. Figure 2 The diagram shows the structure of the magnetic component 33, which is a permanent magnet.

[0054] This invention, through its structural design of the magnetic powder sealing assembly, enables the first pole shoe 31, the magnetic conductive component 34, and the second pole shoe 32 to be sequentially assembled into the inner cavity along its axial direction. When the axial direction of the inner cavity is parallel to the vertical direction, magnetic powder can be injected into the horizontal end face of the pole shoe or the magnetic conductive component 34. During the injection of magnetic powder, the magnetic component 33 can be made unmagnetized or weakly magnetized first to avoid the situation where the magnetic powder is attracted wherever it is injected. This facilitates a more uniform formation of the annular sealing structure during the injection of magnetic powder. After assembly, the magnetic component 33 is energized or magnetized. For example, when the magnetic component 33 is an electromagnet, it is not energized at this time, and energization is performed after the injection of magnetic powder is completed. Or, for example, when the magnetic component 33 is a permanent magnet, it is not magnetized, and magnetization is performed after the injection of magnetic powder is completed.

[0055] Specifically, the first pole piece 31 is first placed in, and magnetic powder is injected into the horizontal end face of the first pole piece 31. Then, the magnetic conductive component 34 and the magnetic component 33 are assembled. Magnetic powder is then injected into the horizontal end face of the magnetic conductive component 34. Finally, the second pole piece 32 is assembled into the inner cavity. This allows magnetic powder to be injected even when the magnetic component 33 is not magnetic or has a weak magnetic field, and ensures that the injection position of the magnetic powder is accurate and the injection amount and distribution of the magnetic powder are uniform.

[0056] The magnetic powder sealing device of the spent nuclear fuel reprocessing equipment in the embodiments of the present invention facilitates the uniform injection of magnetic powder during assembly and improves the uniformity of magnetic powder distribution, thereby making the sealing performance of the magnetic powder sealing structure better and avoiding irreparable damage caused by leakage of hazardous substances such as spent nuclear fuel.

[0057] like Figure 1 and Figure 2 As shown, in some embodiments, the structure of the magnetic powder sealing device of the spent nuclear fuel reprocessing equipment is the same as that of the previous embodiment. The difference is that there are at least two sets of magnetic powder sealing assemblies, and an isolation component is provided between adjacent sets of magnetic powder sealing assemblies. The isolation component includes a magnetic isolation ring 51 and / or a gasket 52. For example, a magnetic isolation ring 51 is provided between the pole shoes in adjacent sets of magnetic powder sealing assemblies, and a gasket 52 is provided between the magnetic conductive components 34 in adjacent sets of magnetic powder sealing assemblies. This ensures that the two magnetic powder sealing assemblies are relatively independent and do not affect each other, and improves the structural stability of the assembly.

[0058] During assembly, multiple magnetic powder sealing components can be assembled sequentially.

[0059] As Figures 1 to 3 shown in the drawings, the following detailed description of some other specific embodiments of the application.

[0060] A magnetic powder sealing device of a nuclear spent fuel reprocessing equipment, comprising a shell 1, a rotating shaft 2, a magnetic powder sealing assembly and an end cover 4. The magnetic powder sealing device of the nuclear spent fuel reprocessing equipment of the embodiment of the application can be applied to the reprocessing equipment of nuclear spent fuel, and is used for sealing substances with high risk level to avoid leakage.

[0061] As Figure 3 shown, the shell 1 comprises a plurality of segmented housings 11, which are connected in sequence along the axis direction of the inner cavity, and the adjacent two segmented housings 11 are coaxially arranged and fixedly connected. At least one magnetic powder sealing assembly is arranged between each segmented housing 11 and the rotating shaft 2. For example, the shell 1 comprises two segmented housings 11, and each segmented housing 11 is provided with a group of magnetic powder sealing assemblies.

[0062] The plurality of segmented housings 11 are internally hollow and configured as the inner cavity of the shell 1. One end of the shell 1 is used for connecting with the nuclear spent fuel reprocessing equipment 7. The rotating shaft 2 is arranged in the inner cavity, and the rotating shaft 2 and the inner cavity are coaxially arranged. The rotating shaft 2 is arranged in the nuclear spent fuel reprocessing equipment 7, and a part of the rotating shaft 2 extends out of the shell of the nuclear spent fuel reprocessing equipment 7. The part of the nuclear spent fuel reprocessing equipment 7 is sealed by the shell 1 and the magnetic powder sealing assembly of the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment, so that the part is not affected in normal operation of the rotating shaft 2 and does not leak.

[0063] The end cover 4 is located at the end of the shell 1 away from the nuclear spent fuel reprocessing equipment 7 and is fixedly connected with the shell 1, so as to ensure the structural stability of the magnetic powder sealing assembly and avoid interference from the external environment. Specifically, after the magnetic powder sealing assembly is assembled in the shell 1, the end cover 4 is connected with the end of the shell 1 away from the nuclear spent fuel reprocessing equipment 7. The end cover 4 is positioned with the shell 1 through the stop 12, and the end cover 4 abuts against the pole shoe in the adjacent magnetic powder sealing assembly, so as to ensure the fixation of the magnetic powder sealing assembly and avoid the movement of the magnetic powder sealing assembly. The end of the shell 1 away from the end cover 4 is positioned with the nuclear spent fuel reprocessing equipment 7 through the stop 12. The end of the shell 1 away from the end cover 4 has a first positioning portion 13, which is used for abutting against and positioning the adjacent magnetic powder sealing assembly. The first positioning portion 13 can be a stepped limiting end face arranged on the wall surface of the inner cavity of the shell 1. When the pole shoe closest to the limiting end face is assembled into the inner cavity, the pole shoe can abut against the limiting end face to achieve positioning.

[0064] The number of the magnetic powder sealing assemblies is multiple, each of which comprises a first pole shoe 31, a second pole shoe 32, a magnetic component 33 and a magnetic conducting component 34, as shown in the figure, a magnetic shielding ring 51 is arranged between the first pole shoe 31 of an upper magnetic powder sealing assembly and the second pole shoe 32 of a lower magnetic powder sealing assembly in the up-down direction, and a gasket 52 is arranged between the magnetic conducting component 34 of the upper magnetic powder sealing assembly and the magnetic conducting component 34 of the lower magnetic powder sealing assembly, so as to realize isolation of adjacent magnetic powder sealing assemblies and guarantee stability of the structure after assembly. The first pole shoe 31 and the second pole shoe 32 are arranged along the axis direction of the inner cavity and connected to the inner wall of the shell 1, after assembly of the first pole shoe 31 and the second pole shoe 32 to the shell 1, the first pole shoe 31 and the second pole shoe 32 are relatively fixed and sealed with the shell 1, for example, a sealing element 35 is arranged between the first pole shoe 31 and the inner wall of the shell 1, between the second pole shoe 32 and the inner wall of the shell 1, and between the magnetic conducting component 34 and the outer wall of the rotating shaft 2; the sealing element 35 can be a sealing ring, an oil seal structure or the like to realize sealing between the first pole shoe 31 and the shell 1, and sealing between the second pole shoe 32 and the shell 1. The first chamber 36 and the second chamber 37 are formed between the first pole shoe 31 and the second pole shoe 32, the magnetic component 33 is arranged in the first chamber 36, and two magnetic poles of the magnetic component 33 respectively abut against the first pole shoe 31 and the second pole shoe 32, specifically, a second positioning portion 38 is arranged on the first pole shoe 31 and the second pole shoe 32, the second positioning portion 38 can be a sink groove or a sink table arranged on the first pole shoe 31 and the second pole shoe 32, and the second positioning portion 38 is used for positioning the magnetic component 33 arranged in the first chamber 36, so as to guarantee that the magnetic component 33 does not shake.

[0065] The magnetic conducting component 34 can be a magnetic conducting sleeve, the magnetic conducting component 34 is connected to the rotating shaft 2, the magnetic conducting component 34 can be connected to the rotating shaft 2 through a thread, a key groove or the like, and a sealing ring can also be arranged between the magnetic conducting component 34 and the rotating shaft 2, so as to guarantee that the contact surface of the magnetic conducting component 34 and the rotating shaft 2 does not leak, and part of the magnetic conducting component 34 is located in the second chamber 37, so that two end surfaces of the magnetic conducting component 34 in the axis direction of the inner cavity respectively form sealing gaps with the first pole shoe 31 and the second pole shoe 32, and the sealing gaps are used for filling the magnetic powder.

[0066] The magnetic component 33 can form a magnetic field at the sealing gap through the first pole shoe 31 and the second pole shoe 32, so that the magnetic powder is stably gathered here to form multiple sealing rings.

[0067] Further, the first pole shoe 31 and the second pole shoe 32 have a plurality of pole teeth 39 arranged along the radial direction of the inner cavity, the magnetic field strength at the pole teeth 39 is much stronger than the magnetic field strength at the tooth slots on both sides of the pole teeth 39, the magnetic powder has a response characteristic to the magnetic field, and the magnetic powder will be firmly adsorbed in the sealing gap at the pole teeth 39, effectively filling the sealing gap, forming a magnetic powder "O" type sealing ring, and ensuring zero leakage of the magnetic powder seal. The magnetic conductive component 34 has a positioning mark corresponding to the pole teeth 39 in the corresponding first pole shoe 31 and / or second pole shoe 32 on the end face in the axial direction of the inner cavity.

[0068] The embodiment of the present application can make the first pole shoe 31, the magnetic conductive component 34, and the second pole shoe 32 be sequentially assembled into the inner cavity along the axial direction of the inner cavity through the structural design of the magnetic powder sealing assembly. When the axial direction of the inner cavity is parallel to the vertical direction, the magnetic powder can be injected onto the horizontal end face of the pole shoe or the magnetic conductive component 34. In the process of injecting the magnetic powder, the magnetic component 33 can be made non-magnetic or weakly magnetic, so as to avoid the situation that the injected magnetic powder is adsorbed to the position where it is injected, facilitate the formation of a ring-shaped sealing structure more uniformly when the magnetic powder is injected, and then the magnetic component 33 is powered or magnetized after the assembly is completed. Specifically, the first pole shoe 31 is placed first, the magnetic powder is injected on the horizontal end face of the first pole shoe 31, then the magnetic conductive component 34 and the magnetic component 33 are assembled, the magnetic powder is injected on the horizontal end face of the magnetic conductive component 34, at this time, the injection position of the magnetic powder can be determined according to the positioning mark, so as to ensure that the injection position of the magnetic powder corresponds to the pole teeth 39 of the second pole shoe 32, and finally the second pole shoe 32 is assembled into the inner cavity. In this way, the injection of the magnetic powder can be performed when the magnetic component 33 is non-magnetic or weakly magnetic, the injection position of the magnetic powder is ensured to be accurate, and the injection amount and distribution of the magnetic powder are uniform. After the magnetic component 33 is powered or magnetized, the magnetic powder is firmly adsorbed at the pole teeth 39 by the magnetic field, and the distribution of the magnetic powder is ensured to be uniform.

[0069] The magnetic powder sealing device of the nuclear spent fuel reprocessing equipment of the embodiment of the present application facilitates uniform injection of the magnetic powder during assembly and improves the uniformity of the distribution of the magnetic powder, so that the sealing performance of the magnetic powder sealing structure is better, and the irreversible harm caused by leakage of dangerous substances such as nuclear spent fuel is avoided.

[0070] As shown in Figures 4 to 6 The magnetic powder injection method of the embodiment of the present application is used for injecting the magnetic powder into the sealing gap of the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment in any one of the above embodiments, and the magnetic powder injection method comprises the following steps.

[0071] S1, install the shell 1 and the rotating shaft 2 in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment on the nuclear spent fuel reprocessing equipment 7, and open the end of the inner cavity of the shell 1 away from the nuclear spent fuel reprocessing equipment 7 to the upper side of the gravity direction. The up-down direction in the figure is the gravity direction, and the shell 1 is positioned with the nuclear spent fuel reprocessing equipment 7 through the stop 12 and is fixedly connected through the connecting members such as bolts.

[0072] S2, assemble the first pole shoe 31 in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment in the inner cavity of the shell 1, and inject magnetic powder into the space above the pole teeth 39 of the first pole shoe 31 to form a plurality of magnetic powder O-rings. As shown in Figure 4 and Figure 5 Generally, a plurality of pole teeth 39 concentrically distributed along the radial direction of the rotating shaft 2 are arranged on the first pole shoe 31, and an appropriate amount of magnetic powder is uniformly injected into the space above each row of pole teeth 39 to form a plurality of magnetic powder O-rings, the width of the magnetic powder O-ring is 0.2mm to 0.4mm, for example, the width of the magnetic powder O-ring is 0.3mm, and the height of the magnetic powder O-ring is 0.1mm to 0.2mm.

[0073] S3, assemble the magnetic component 33 and the magnetic conducting component 34 in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment in the inner cavity of the shell 1, the magnetic component 33 is non-magnetic or the magnetic field strength of the magnetic component 33 is less than the first threshold value, and the magnetic field strength of the magnetic component 33 needs to be non-magnetic or weak magnetic, which will not cause the magnetic powder to be directly adsorbed on the pole teeth 39 when the magnetic powder is injected, and the magnetic powder is injected into the position corresponding to the pole teeth 39 in the second pole shoe 32 above the magnetic conducting component 34 to form a plurality of magnetic powder O-rings. The magnetic component 33 is positioned corresponding to the second positioning part 38 (a sink groove or a sink table arranged on the first pole shoe 31) on the first pole shoe 31, and when the magnetic conducting component 34 has a positioning mark, the injection of the magnetic powder can be carried out according to the positioning mark, so as to ensure that the injection position corresponds to the position of the pole teeth 39 on the second pole shoe 32, the width of the magnetic powder O-ring is 0.2mm to 0.4mm, for example, the width of the magnetic powder O-ring is 0.3mm, and the height of the magnetic powder O-ring is 0.1mm to 0.2mm.

[0074] S4, assemble the second pole shoe 32 in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment in the inner cavity of the shell 1. In steps S2 and S3, the injection height of the magnetic powder O-ring can be slightly higher than the height of the sealing gap, so that after the assembly is completed, the magnetic powder O-ring can be extruded to a certain extent, thereby improving the compactness of the magnetic powder.

[0075] S5, connect the end cover 4 to the shell 1, and position the end cover 4 and the shell 1 through the stop 12 and fix them through connecting members such as bolts, and the end cover 4 can also abut against the second pole shoe 32, so as to ensure that the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment will not move.

[0076] S6, the rotation shaft 2 is driven to rotate to drive the magnetic component 34 to rotate relative to the first pole shoe 31 and the second pole shoe 32. The rotation speed of the rotation shaft 2 is 0.05r / s to 1r / s, and the rotation shaft 2 rotates 1 to 5 rounds. The rotation is used to make the magnetic powder in each magnetic powder O-shaped ring more evenly distributed, and to ensure that no leakage occurs.

[0077] S7, the magnetic component 33 is energized or magnetized to make the magnetic field strength of the magnetic component 33 reach a second threshold value, wherein the second threshold value is greater than the first threshold value. The second threshold value is much greater than the first threshold value, and when the magnetic field strength reaches the second threshold value, the magnetic powder can be stably adsorbed at the pole tooth 39 to form a seal. For example, when the magnetic component 33 is an electromagnet, the magnetic field strength can be controlled by energizing. In steps S3 to S6, the electromagnet is not energized, and in step S7, the electromagnet is energized. For another example, when the magnetic component 33 is a permanent magnet, in steps S3 to S6, the permanent magnet is not magnetized or only has weak magnetism, and in step S7, the permanent magnet is magnetized.

[0078] In some embodiments, the number of magnetic powder sealing assemblies in the magnetic powder sealing device of the nuclear spent fuel reprocessing equipment is multiple; the magnetic powder injection method of the present embodiment is basically the same as that of the previous embodiment, and the difference is that before the operation of step S5 is performed, the following steps are included:

[0079] The isolation component (magnetic isolation ring 51) is placed in the inner cavity of the shell 1, which is used to isolate the assembled second pole shoe 32 from the magnetic powder sealing assembly located above it, and the steps S2 to S4 are repeated to complete the assembly of the next magnetic powder sealing assembly and the injection of the magnetic powder. At this time, the assembly of the second magnetic powder sealing assembly is completed.

[0080] When the number of magnetic powder sealing assemblies is more than three, the above step can be repeated until the assembly of all magnetic powder sealing assemblies and the injection of the magnetic powder are completed.

[0081] In some embodiments, the magnetic powder injection method of the present embodiment is basically the same as the magnetic powder injection method in the above embodiments, except that when the shell 1 comprises a plurality of segmented shells 11 and the number of magnetic powder sealing assemblies is multiple, the plurality of segmented shells 11 can be sequentially connected in step S1, and then assembled on the spent nuclear fuel reprocessing equipment 7. If the first positioning part 13 (the stepped limiting end surface) is arranged in each segmented shell 11, the segmented shell 11 closest to the spent nuclear fuel reprocessing equipment 7 needs to be installed on the spent nuclear fuel reprocessing equipment 7 in step S1, and the operations of S2 to S4 are performed to complete the installation of the magnetic powder sealing assembly corresponding to the segmented shell 11. Then the next segmented shell 11 is installed, and the operations of S2 to S4 are performed, and the installation of the plurality of segmented shells 11 and the magnetic powder sealing assemblies corresponding thereto is sequentially performed, and finally the operations of steps S5 to S7 are performed.

[0082] In the embodiment of the present application, the magnetic field strength generated by the magnetic component as a magnetic source during the magnetic powder injection process is 0 or very small, and the adsorption force of the magnetic powder is almost 0. The technical problem that the magnetic powder is adsorbed where it is injected during the magnetic powder injection due to the response characteristics of the magnetic powder as a superparamagnetic substance to the magnetic field is solved, and the uniformity of the magnetic powder injection is ensured.

[0083] In the embodiment of the present application, the magnetic powder injection process is synchronized with the installation and assembly process of the device. When the magnetic powder is injected above the first pole shoe or the magnetic conducting part, there is enough space above the first pole shoe and the magnetic conducting part for the injection of the magnetic powder, and the position and state of the magnetic powder after injection can be clearly observed, which facilitates timely adjustment of the magnetic powder. The technical problem that the magnetic powder is difficult to be effectively injected due to the small sealing gap is solved, and the accuracy of the magnetic powder injection is ensured.

[0084] After the installation of the magnetic powder sealing assembly is completed, the driving shaft is driven to rotate, which drives the magnetic conducting part (magnetic conducting sleeve) to rotate synchronously. For example, the driving shaft and the magnetic conducting part are slowly rotated at a speed of 0.05-1 r / s for 1 to 5 turns by relying on the tooling, which can drive the magnetic powder to move circumferentially, solve the technical problem that the magnetic powder is difficult to be uniformly injected due to the poor flowability of the magnetic powder as a solid compared to a liquid, and facilitate the formation of a more uniform O-ring of the magnetic powder.

[0085] In the embodiment of the present application, the magnetic component can be an electromagnet or a permanent magnet. After the magnetic powder sealing assembly is assembled and rotates through the rotating shaft, the magnetic powder is more uniformly distributed. Then, after a strong current is passed through the electromagnet or the permanent magnet is magnetized, the magnetic component, the pole shoe and the magnetic conducting component form a magnetic circuit. Since the gap (generally 0.1-0.2mm) between the pole teeth and the magnetic conducting component is much smaller than the gap between the tooth slots on both sides of the pole teeth and the magnetic sleeve, the magnetic field strength at the pole teeth is much stronger than the magnetic field strength at the tooth slots on both sides of the pole teeth. The magnetic powder has a response characteristic to the magnetic field, and the magnetic powder will be firmly attracted to the sealing gap at the pole teeth. The height of the magnetic powder injection is consistent with the size of the sealing gap, which avoids the waste of the magnetic powder and effectively fills the sealing gap to form a magnetic powder "O" type sealing ring, thereby ensuring zero leakage of the magnetic powder sealing.

[0086] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0087] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0088] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0089] In the present application, unless specifically stated and limited otherwise, a first feature "on" or "under" a second feature can be directly in contact with the second feature, or indirectly in contact with the second feature through an intermediate medium. Also, a first feature "over", "above" and "on top of" a second feature can be directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can be directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0090] In the present application, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material or characteristic is included in at least one embodiment or example of the present application. Exemplary representations of the above terms in the present specification are not necessarily directed to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0091] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A magnetic powder injection method, characterized in that, For injecting magnetic powder into the sealing gap of a magnetic powder sealing device in a spent nuclear fuel reprocessing facility, the magnetic powder sealing device of the spent nuclear fuel reprocessing facility comprising: A housing having an internal cavity, one end of which is used for connection to a spent nuclear fuel reprocessing facility; A rotating shaft is disposed in the inner cavity, and the rotating shaft and the inner cavity are arranged coaxially; A magnetic powder sealing assembly includes a first pole shoe, a second pole shoe, a magnetic component, and a magnetically conductive component. The first pole shoe and the second pole shoe are arranged along the axial direction of the inner cavity and connected to the inner wall of the housing. A first chamber and a second chamber are formed between the first pole shoe and the second pole shoe. The magnetic component is disposed in the first chamber and its two magnetic poles abut against the first pole shoe and the second pole shoe, respectively. The magnetically conductive component is connected to the rotating shaft, and a portion of the magnetically conductive component is located in the second chamber, so that the two end faces of the magnetically conductive component in the axial direction of the inner cavity form the sealing gap between the first pole shoe and the second pole shoe, respectively. The sealing gap is used to fill magnetic powder. An end cap, located at the end of the housing furthest from the spent nuclear fuel reprocessing facility and fixedly connected to the housing; The magnetic powder injection method includes: S1. Install the housing and rotating shaft of the magnetic powder sealing device of the spent nuclear fuel reprocessing equipment onto the spent nuclear fuel reprocessing equipment, with the opening of the inner cavity of the housing away from the spent nuclear fuel reprocessing equipment facing upward in the direction of gravity. S2. Assemble the first pole shoe of the magnetic powder sealing device of the spent nuclear fuel reprocessing equipment into the inner cavity of the shell, and inject magnetic powder into the space above the pole teeth of the first pole shoe to form multiple magnetic powder O-rings. S3. Assemble the magnetic component and the magnetic conductive component in the magnetic powder sealing device of the spent nuclear fuel reprocessing equipment into the inner cavity of the shell. The magnetic component is non-magnetic or the magnetic field strength of the magnetic component is less than the first threshold. Inject magnetic powder at the position above the magnetic conductive component corresponding to the pole teeth in the second pole shoe to form multiple magnetic powder O-rings. S4. Assemble the second pole shoe in the magnetic powder sealing device of the spent nuclear fuel reprocessing equipment into the inner cavity of the housing; S5. Connect the end cap to the housing; S6. Drive the rotating shaft to rotate, so as to drive the magnetic conductive component to rotate relative to the first pole shoe and the second pole shoe; S7. The magnetic component is energized or magnetized to make the magnetic field strength of the magnetic component reach a second threshold, wherein the second threshold is greater than the first threshold.

2. The magnetic powder injection method according to claim 1, characterized in that, The number of magnetic powder sealing assemblies is at least two sets.

3. The magnetic powder injection method according to claim 2, characterized in that, The housing includes multiple segmented outer shells, which are sequentially connected along the axial direction of the inner cavity. Two adjacent segmented outer shells are arranged coaxially and fixedly connected. At least one magnetic powder sealing assembly is provided between each segmented outer shell and the rotating shaft.

4. The magnetic powder injection method according to claim 2, characterized in that, An isolation component is provided between two adjacent sets of the magnetic powder sealing assemblies, the isolation component including a magnetic shielding ring and / or a gasket.

5. The magnetic powder injection method according to claim 1, characterized in that, The end cap is positioned to the housing via a stop, and the end cap abuts against the adjacent magnetic powder sealing assembly; the end of the housing away from the end cap is positioned to the spent nuclear fuel reprocessing equipment via a stop, and the end of the housing away from the end cap has a first positioning part, which is used to abut against and position itself against the adjacent magnetic powder sealing assembly.

6. The magnetic particle injection method according to any one of claims 1 to 5, characterized in that, The magnetic component is a permanent magnet or an electromagnet; And / or, it also includes a sealing element, wherein the sealing element is provided between the first pole shoe and the inner wall of the housing, between the second pole shoe and the inner wall of the housing, and between the magnetic conductive component and the outer wall of the rotating shaft; And / or, the first pole shoe and the second pole shoe are provided with a second positioning part, which is used to position the magnetic component arranged in the first room; And / or, the first pole shoe and the second pole shoe have a plurality of pole teeth arranged radially along the inner cavity, and the magnetically conductive component has a positioning mark on its end face in the axial direction of the inner cavity that corresponds to the pole teeth in the corresponding first pole shoe and / or second pole shoe.

7. The magnetic powder injection method according to claim 1, characterized in that, The magnetic powder sealing device of the nuclear spent fuel reprocessing equipment has multiple magnetic powder sealing components. Before step S5, the following steps are also included: Place the isolation component into the inner cavity of the housing to isolate the assembled second pole shoe from the magnetic powder sealing assembly located above it. Repeat steps S2 to S4 to complete the assembly of the next magnetic powder sealing assembly and the injection of magnetic powder. Repeat the previous step until all magnetic powder sealing components are assembled and magnetic powder is injected.

8. The magnetic powder injection method according to claim 1, characterized in that, The width of the magnetic powder O-ring is 0.2 mm to 0.4 mm, and the height of the magnetic powder O-ring is 0.1 mm to 0.2 mm.

9. The magnetic powder injection method according to claim 1, characterized in that, In step S6, the rotational speed of the shaft is 0.05 r / s to 1 r / s, and the shaft rotates 1 to 5 revolutions.

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