Crushing apparatus for polycrystal silicon and crushing method for polycrystal silicon

Abstract

To improve a yield of polycrystal silicon having a desired particle size, and sufficiently reduce a generation amount of fine powder of the polycrystal silicon.SOLUTION: A crushing apparatus (1) for polycrystal silicon (S) includes a driving part (30) for sandwiching the polycrystal silicon (S) between a first member (10) and a second member (20), and thereby crushing the polycrystal silicon (S), wherein the driving part (30) drives at least one of the first member (10) and the second member (20) so that a shortest interval (D1) between the first member (10) and the second member (20) is 17 mm or more and 30 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and a method for crushing polycrystalline silicon. [Background technology]

[0002] Patent Document 1 discloses a method for crushing polycrystalline silicon using a jaw crusher that has a fixed blade and a movable blade and that can adjust the minimum gap between the fixed blade and the movable blade to 2 to 16 mm. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-047594 A Summary of the Invention [Problem to be solved by the invention]

[0004] The shortest gap between the fixed blade and the movable blade disclosed in Patent Document 1 generates a large amount of polycrystalline silicon fine powder, which causes a problem in that the yield of polycrystalline silicon with the desired particle size cannot be sufficiently high.

[0005] An object of one aspect of the present invention is to improve the yield of polycrystalline silicon having a desired particle size while sufficiently reducing the amount of fine powder of polycrystalline silicon generated. [Means for solving the problem]

[0006] In order to solve the above problems, a polycrystalline silicon crushing device according to one embodiment of the present invention includes a first member, a second member arranged to face the first member, and a drive unit that drives at least one of the first member and the second member to crush the polycrystalline silicon by sandwiching the polycrystalline silicon between the first member and the second member, and the drive unit drives at least one of the first member and the second member so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less.

[0007] Moreover, a method for crushing polycrystalline silicon according to one embodiment of the present invention includes a feeding step of feeding polycrystalline silicon between a first member and a second member arranged opposite the first member, and a driving step of driving at least one of the first member and the second member to crush the polycrystalline silicon by sandwiching the polycrystalline silicon fed by the feeding step between the first member and the second member, wherein in the driving step, at least one of the first member and the second member is driven so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less. Effect of the Invention

[0008] According to one aspect of the present invention, it is possible to improve the yield of polycrystalline silicon having a desired particle size and to sufficiently reduce the amount of fine powder of polycrystalline silicon generated. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a polycrystalline silicon crushing device according to one embodiment of the present invention. [Diagram 2] 2 is a diagram for explaining a first sensor provided in the crushing device shown in FIG. 1. FIG. [Diagram 3] FIG. 2 is a diagram for explaining the shortest distance between a first member and a second member in the crushing device shown in FIG. [Figure 4]2 is a diagram for explaining a housing provided below a first member and a second member included in the crushing device shown in FIG. 1. FIG. [Diagram 5] 1. FIG. 4 is a schematic diagram showing an example of the configuration of a crushing device as a second modified example of the crushing device shown in FIG. [Figure 6] 1 is a graph showing the fine powder generation rate and yield according to Example 1 of the present invention. [Figure 7] 11 is a graph showing the relationship between the filling rate and the ratio according to Example 2 of the present invention. [Figure 8] 10 is a graph showing the relationship between the fine powder generation rate and the yield in Example 3 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Polycrystalline silicon crushing device] Fig. 1 is a schematic diagram showing an example of the configuration of a crushing device 1 for polycrystalline silicon S according to an embodiment of the present invention. Fig. 2 is a diagram for explaining a first sensor 50 provided in the crushing device 1 shown in Fig. 1. In Fig. 2, the driving unit 30, the control unit 60, the plate receiving unit 70, and the toggle plate T1 are omitted. The following description will explain the crushing device 1, but also includes an explanation of a method for crushing polycrystalline silicon S.

[0011] The crushing device 1 is a device for crushing polycrystalline silicon S, and is called a jaw crusher. As shown in Fig. 1, the crushing device 1 includes a first member 10, a second member 20, a driving unit 30, a conveying unit 40, a first sensor 50, a control unit 60, a plate receiving unit 70, and a toggle plate T1.

[0012] (First member and second member) The first member 10 is fixed at a predetermined position, and is fixed to a frame (not shown) provided in the crushing device 1. The first member 10 has fixed teeth 10a. The first member 10 and the second member 20 are used to crush the polycrystalline silicon S. The second member 20 is fixed to the driving unit 30, and is disposed so as to face the first member 10. The second member 20 has movable teeth 20a.

[0013] (Drive unit) The driving unit 30 drives the second member 20, and crushes the polycrystalline silicon S by sandwiching the polycrystalline silicon S input by the transport unit 40 between the first member 10 and the second member 20. The driving unit 30 has a rotating shaft 31, and the second member 20 is fixed to the rotating shaft 31. The driving unit 30 has a motor (not shown), and rotates the rotating shaft 31 with the motor to move the second member 20 with the rotating shaft 31 as a reference. In this way, the driving unit 30 drives the second member 20 so that the distance between the first member 10 and the second member 20 is changed.

[0014] The driving unit 30 drives the second member 20 so that the shortest distance D1 between the first member 10 and the second member 20 is 17 mm or more and 30 mm or less. Specifically, the shortest distance D1 is the distance when the first member 10 and the second member 20 are closest to each other. In other words, in the driving unit 30, the range in which the rotating shaft 31 can rotate is limited so that the shortest distance D1 is 17 mm or more and 30 mm or less.

[0015] In this manner, the driving unit 30 drives the second member 20 so that the shortest distance D1 between the first member 10 and the second member 20 is 17 mm or more and 30 mm or less. This makes it possible to improve the yield of polycrystalline silicon S having a particle size of more than 8 mm and 50 mm or less, and to reduce the amount of fine powder of polycrystalline silicon S having a particle size of 8 mm or less that is generated.

[0016] Such an effect also contributes to the achievement of, for example, Goal 12 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "ensuring sustainable consumption and production patterns." Details of the effect of improving the yield of polycrystalline silicon S and the effect of reducing the amount of fine powder of polycrystalline silicon S will be described in Example 1 below.

[0017] Furthermore, as described above, when the first member 10 and the second member 20 are in the closest state, the shortest distance D1 between the first member 10 and the second member 20 is 17 mm or more and 30 mm or less. This makes it possible to further improve the yield of polycrystalline silicon S having a particle size of more than 8 mm and not more than 50 mm, and to further reduce the amount of fine powder of polycrystalline silicon S having a particle size of 8 mm or less that is generated.

[0018] 3 is a diagram for explaining the shortest distance D1 between the first member 10 and the second member 20 in the crushing device 1 shown in FIG. 3 is a diagram showing the fixed teeth 10a of the first member 10 and the movable teeth 20a of the second member 20 as viewed from above. As shown in FIG. 3, the fixed teeth 10a and the movable teeth 20a each have a plurality of crests M1 and a plurality of valleys V1 formed alternately. The shortest distance D1 is the distance between the apex of the crest M1 of one of the fixed teeth 10a and the movable teeth 20a and the lowest position of the valley V1 facing the crest M1 of the other of the fixed teeth 10a and the movable teeth 20a.

[0019] (Transportation section) The transport unit 40 transports the polycrystalline silicon S, thereby feeding the polycrystalline silicon S from above between the first member 10 and the second member 20. The process in which the transport unit 40 feeds the polycrystalline silicon S is an example of a feeding process. The polycrystalline silicon S fed from the transport unit 40 enters between the fixed teeth 10a and the movable teeth 20a, is crushed by the fixed teeth 10a and the movable teeth 20a, and falls downward from the gap between the fixed teeth 10a and the movable teeth 20a.

[0020] The conveying unit 40 may include, for example, a vibrating feeder (not shown) that conveys the polycrystalline silicon S by vibrating. The polycrystalline silicon S is conveyed in a conveying direction F1 by the vibration of the vibrating feeder. The conveying direction F1 is a direction from the conveying unit 40 toward the driving unit 30. The vibration of the vibrating feeder is controlled by the control unit 60.

[0021] The vibrating feeder vibrates in an obliquely upward direction relative to the conveying direction F1. Specifically, the vibration direction of the vibrating feeder is between the conveying direction F1 and a vertically upward direction perpendicular to the horizontal plane. The vibrating feeder is, for example, a vibrating feeder that vibrates using a vibrator, or an electromagnetic feeder that vibrates using an electromagnet.

[0022] By using the vibrating feeder as the conveying unit 40 that conveys the polycrystalline silicon S, it is easy to control the discharge of the polycrystalline silicon S to the outside of the conveying unit 40. In addition, since the vibrating feeder vibrates, a plurality of polycrystalline silicon S spreads in the horizontal direction on the conveying unit 40, the amount of polycrystalline silicon S input between the first member 10 and the second member 20 can be made as constant as possible.

[0023] (First sensor) 2, the first sensor 50 is provided above the first member 10 and the second member 20. The first sensor 50 detects a distance D2 between the first sensor 50 and the polycrystalline silicon S sandwiched between the first member 10 and the second member 20. The first sensor 50 is, for example, a laser sensor having a light emitting unit (not shown) that emits laser light L1 downward, and a light receiving unit (not shown) that receives light L2 that is the laser light L1 reflected by the polycrystalline silicon S.

[0024] Specifically, the first sensor 50 may be, for example, a laser sensor that detects the distance D2 based on the period from when the light-emitting unit emits the laser light L1 to when the light-receiving unit receives the light L2. The first sensor 50 may also be a triangulation type laser sensor.

[0025] (Control unit) The control unit 60 controls the driving of the driving unit 30 and the transportation of the transport unit 40. The control unit 60 controls the driving of the transport unit 40 based on the detection result of the distance D2 by the first sensor 50. There is a negative correlation between the distance D2 detected by the first sensor 50 and the filling rate of the polycrystalline silicon S.

[0026] Specifically, the shorter the distance D2, the higher the filling rate of the polycrystalline silicon S, and the longer the distance D2, the lower the filling rate of the polycrystalline silicon S. The filling rate of the polycrystalline silicon S is the ratio of the volume of the portion filled with the polycrystalline silicon S to the volume of the space SP1 between the fixed teeth 10a and the movable teeth 20a.

[0027] The control unit 60 determines whether the distance D2 detected by the first sensor 50 is equal to or greater than a predetermined value. When the control unit 60 determines that the distance D2 detected by the first sensor 50 is equal to or greater than the predetermined value, the control unit 60 continues driving the conveying unit 40, that is, continues vibrating the vibrating feeder.

[0028] On the other hand, when the control unit 60 determines that the distance D2 detected by the first sensor 50 is less than the predetermined value, it stops driving the conveying unit 40, that is, stops the vibration of the vibrating feeder. The control unit 60 controls the driving of the conveying unit 40 based on the detection result of the first sensor 50, thereby enabling the filling rate of the polycrystalline silicon S to be accurately controlled.

[0029] Furthermore, the control unit 60 continues driving the drive unit 30 while controlling the driving of the transport unit 40. As a result, while the transport of the transport unit 40 is stopped, the polycrystalline silicon S is crushed by the first member 10 and the second member 20 and falls downward from the gap between the first member 10 and the second member 20, thereby decreasing the filling rate of the polycrystalline silicon S. When the distance D2 becomes equal to or greater than the predetermined value after the control unit 60 stops driving the transport unit 40, the control unit 60 resumes driving the transport unit 40.

[0030] In this manner, the control unit 60 controls the driving of the transport unit 40 based on the detection result of the first sensor 50 that detects the distance D2 between the polycrystalline silicon S sandwiched between the first member 10 and the second member 20 and the first sensor 50. This makes it possible to precisely control the amount of polycrystalline silicon S sandwiched between the first member 10 and the second member 20.

[0031] Therefore, it is possible to control the amount of polycrystalline silicon S sandwiched between the first member 10 and the second member 20 so as to improve the yield of polycrystalline silicon S of a desired size and reduce the amount of fine powder of polycrystalline silicon S generated. Details of the effect of improving the yield of polycrystalline silicon S and reducing the amount of fine powder of polycrystalline silicon S generated will be described in Example 2 below.

[0032] (Plate receiving part and toggle plate) A toggle plate T1 is connected to the lower part of the second member 20 on the opposite side to the movable teeth 20a. The toggle plate T1 connects the lower part of the second member 20 and the plate receiving part 70 so as to be relatively movable. The crushing device 1 is a single toggle type device equipped with one toggle plate T1. The plate receiving part 70 is fixed to the above-mentioned frame.

[0033] (Housing) Fig. 4 is a diagram for explaining a housing 80 provided below the first member 10 and the second member 20 included in the crushing device 1 shown in Fig. 1. In Fig. 4, the driving unit 30, the transport unit 40, the first sensor 50, the control unit 60, the plate receiving unit 70, and the toggle plate T1 are omitted. As shown in Fig. 4, the crushing device 1 may further include housings 80 and 81, a detector 82, and a second sensor 83.

[0034] The housing 80 is provided below the first member 10 and the second member 20, and forms a space SP2 in which polycrystalline silicon S crushed by the first member 10 and the second member 20 accumulates. In the space SP2, polycrystalline silicon S that falls downward from a gap between the first member 10 and the second member 20 accumulates. The housing 80 is made of, for example, resin, and is formed in a box shape that is open at the top.

[0035] In this way, the polycrystalline silicon S crushed by the first member 10 and the second member 20 is deposited in the space SP2 formed by the housing 80, and therefore, among the polycrystalline silicon S deposited in the housing 80, there is polycrystalline silicon S that does not come into contact with the housing 80. Therefore, it is possible to reduce the contact of the polycrystalline silicon S with other members, and to reduce surface contamination of the polycrystalline silicon S.

[0036] Furthermore, by accumulating polycrystalline silicon S in the housing 80, in a state in which polycrystalline silicon S has accumulated in the housing 80, the polycrystalline silicon S that falls downward from the first member 10 and the second member 20 collides with the polycrystalline silicon S already accumulated in the housing 80, and does not collide with the bottom surface 80a of the housing 80. Therefore, it is possible to reduce the contact of the polycrystalline silicon S with the housing 80, and to reduce the contamination of the surface of the polycrystalline silicon S with the resin.

[0037] The housing 81 is connected to the side of the housing 80, and the inside of the housing 81 communicates with the inside of the housing 80. That is, the space SP3 formed by the housing 81 communicates with the space SP2 formed by the housing 80. The polycrystalline silicon S that flows from the space SP2 into the space SP3 enters the space SP3. The housing 81 is made of, for example, resin, and is formed in a box shape with an open bottom. The polycrystalline silicon S that falls from below the housing 81 is placed on the detector 82. The housing 81 extends downward beyond the bottom surface 80a of the housing 80.

[0038] (Second sensor) The second sensor 83 is provided inside the housing 80 and detects whether the polycrystalline silicon S deposited inside the housing 80 has reached a predetermined height H1 from the bottom surface 80a of the housing 80. The second sensor 83 may be the same sensor as the first sensor 50. The light-emitting unit of the second sensor 83 emits, for example, laser light in the horizontal direction, and the light-receiving unit of the second sensor 83 receives light that is the laser light emitted from the light-emitting unit and reflected by the polycrystalline silicon S. When the light-receiving unit receives the light, the second sensor 83 detects that the polycrystalline silicon S has reached the predetermined height H1.

[0039] When the second sensor 83 detects that the polycrystalline silicon S accumulated inside the housing 80 has reached a predetermined height H1, the control unit 60 stops driving the transport unit 40. This prevents the polycrystalline silicon S from continuing to accumulate inside the housing 80, and prevents the polycrystalline silicon S from clogging the inside of the housing 80. In addition, it is possible to prevent a part of the polycrystalline silicon S from being exposed to the outside of the housing 80, and to prevent the polycrystalline silicon S from contacting members outside the housing 80. Therefore, it is possible to reduce surface contamination of the polycrystalline silicon S.

[0040] Specifically, it is possible to prevent the polycrystalline silicon S from continuing to accumulate inside the housing 80, thereby reducing the possibility of hanging occurring inside the housing 80. In addition, it is possible to prevent a part of the polycrystalline silicon S from being exposed to the outside of the housing 80, thereby preventing the polycrystalline silicon S from contacting the first member 10 or the second member 20.

[0041] (Detector) The detector 82 is, for example, a metal detector that detects the presence of an object containing metal. The detector 82 detects the polycrystalline silicon S that has fallen from below the housing 81 and that is placed on the detector 82. The detector 82 also functions as a placement table on which the polycrystalline silicon S can be placed.

[0042] The detector 82 may be capable of supplying the polycrystalline silicon S from a first position to a second position and moving between the first position and the second position. The first position is a position where the polycrystalline silicon S dropping from below the housing 81 can be placed. The second position is a position away from the first position, for example, a position to which the polycrystalline silicon S is supplied.

[0043] The movement of the detector 82 may be controlled by the control unit 60. The detector 82 places the polycrystalline silicon S that has fallen from below the housing 81 at the first position, and supplies the polycrystalline silicon S to the second position. Furthermore, the polycrystalline silicon S may be removed from the detector 82 at the second position. When the polycrystalline silicon S is removed, the detector 82 returns from the second position to the first position.

[0044] [Variation 1] The driving unit 30 may drive at least one of the first member 10 and the second member 20. In this case, the driving unit 30 crushes the polycrystalline silicon S by sandwiching the polycrystalline silicon S between the first member 10 and the second member 20. The driving unit 30 drives at least one of the first member 10 and the second member 20 so that the shortest distance D1 is 17 mm or more and 30 mm or less. The process in which the driving unit 30 drives at least one of the first member 10 and the second member 20 is an example of a driving process.

[0045] For example, the driving unit 30 may drive only the first member 10 out of the first member 10 and the second member 20. In this case, the first member 10 is fixed to the driving unit 30, and the second member 20 is fixed to the above-mentioned frame.

[0046] Furthermore, the driving unit 30 may drive both the first member 10 and the second member 20. In this case, the first member 10 is fixed to a rotation shaft other than the rotation shaft 31 shown in Fig. 1, and the second member 20 is fixed to the rotation shaft 31. The driving unit 30 has the other rotation shaft, rotates the other rotation shaft by a motor (not shown), and moves the first member 10 based on the other rotation shaft.

[0047] [Modification 2] Fig. 5 is a schematic diagram showing an example of the configuration of a crushing device 1D as a second modification of the crushing device 1 shown in Fig. 1. As shown in Fig. 5, the crushing device 1D includes a first member 10D, a second member 20D, a driving unit 30D, a plate receiving unit 70D, toggle plates T2, T3, and a support unit TS. The crushing device 1D further includes a conveying unit 40, a first sensor 50, and a control unit 60 shown in Fig. 1. The crushing device 1D may further include housings 80, 81, a detector 82, and a second sensor 83 shown in Fig. 4.

[0048] The first member 10D is the same as the first member 10, the second member 20D is the same as the second member 20, and the driving unit 30D is the same as the driving unit 30. A toggle plate T2 is connected to the lower part of the second member 20D. The toggle plate T2 connects the lower part of the second member 20D and the support part TS so that they can move relative to each other. The support part TS is fixed to a frame provided in the crushing device 1D.

[0049] The toggle plate T3 connects the plate receiving portion 70D and the support portion TS so as to be movable relative to each other. The plate receiving portion 70D is fixed to the above-mentioned frame provided in the crushing device 1D. The crushing device 1D is a double toggle type device provided with two toggle plates T2 and T3. The crushing device 1 can reduce the amount of fine powder of the polycrystalline silicon S generated compared to the crushing device 1D, but the crushing device 1D may also be included in the technical scope of the present invention.

[0050] Example 1 Fig. 6 is a graph showing the fine powder generation rate and the yield in Example 1 of the present invention. In Example 1, in the crushing device 1 shown in Fig. 1, the shortest distance D1 between the first member 10 and the second member 20 was changed to crush the polycrystalline silicon S.

[0051] 6, the horizontal axis indicates the shortest distance D1 [mm], and the vertical axis indicates the fine powder generation rate [%]. The fine powder generation rate is the ratio of the amount of fine powder of polycrystalline silicon S having a particle size of 8 mm or less generated to the amount of polycrystalline silicon S input between the first member 10 and the second member 20.

[0052] 6, the horizontal axis indicates the shortest distance D1 [mm], and the vertical axis indicates the yield [%]. The yield is the ratio of the amount of polycrystalline silicon S having a particle size of 50 mm or less to the amount of polycrystalline silicon S input between the first member 10 and the second member 20.

[0053] The present inventors conducted extensive research into the shortest distance D1 with respect to the results shown in the graphs denoted by reference numerals 601 and 602 in Fig. 6. As a result, the present inventors found a numerical range RA of the shortest distance D1 that maximizes the yield of polycrystalline silicon S having an optimal particle size while minimizing the fine powder generation rate. Here, the optimal particle size is a size that is greater than 8 mm and equal to or less than 50 mm. The numerical range RA is equal to or greater than 17 mm and equal to or less than 30 mm.

[0054] Example 2 Fig. 7 is a graph showing the relationship between the filling rate and the ratio according to Example 2 of the present invention. In Example 2, the filling rate of the polycrystalline silicon S described above was changed in the crushing device 1 shown in Fig. 1 to crush the polycrystalline silicon S. In the graph shown in Fig. 7, the horizontal axis indicates the filling rate [%], and the vertical axis indicates the ratio [%] of the amount of specific polycrystalline silicon S to the amount of polycrystalline silicon S introduced between the first member 10 and the second member 20.

[0055] 7, graph G1 shows the ratio of the amount of fine powder of polycrystalline silicon S having a particle size of 8 mm or less to the amount of charged polycrystalline silicon S. Graph G2 shows the ratio of the amount of polycrystalline silicon S having a particle size of 50 mm or less to the amount of charged polycrystalline silicon S. Graph G3 shows the ratio of the amount of polycrystalline silicon S having a particle size larger than 50 mm to the amount of charged polycrystalline silicon S.

[0056] 7, as the filling rate increases, the proportion of the amount of polycrystalline silicon S having a particle size of 50 mm or less increases, while the proportion of the amount of fine powder of polycrystalline silicon S having a particle size of 8 mm or less increases. Therefore, if the filling rate increases too much, multiple polycrystalline silicon S collide with each other, causing cracks and being crushed into smaller pieces than necessary.

[0057] 7, in order to reduce the amount of fine powder generated while increasing the amount of polycrystalline silicon S having a particle size of 50 mm or less, it is preferable to control the filling rate. Therefore, as described above, it is preferable that the control unit 60 controls the driving of the conveying unit 40 based on the detection result of the distance D2 by the first sensor 50.

[0058] Example 3 Fig. 8 is a graph showing the relationship between the fine powder generation rate and the yield rate according to Example 3 of the present invention. In Example 3, polycrystalline silicon S was crushed in each of the single toggle type crushing device 1 shown in Fig. 1 and the double toggle type crushing device 1D shown in Fig. 5. In the graph shown in Fig. 8, the horizontal axis indicates the fine powder generation rate [%], and the vertical axis indicates the yield rate [%]. The definitions of the fine powder generation rate and the yield rate in Fig. 8 are the same as those defined in Example 1.

[0059] In the graph shown in Fig. 8, graph G4 shows the yield when crushing polycrystalline silicon S using the crusher 1, and graph G5 shows the yield when crushing polycrystalline silicon S using the crusher 1D. As shown in Fig. 8, when the crusher 1 was used, the yield tended to be higher and the fine powder generation rate lower than when the crusher 1D was used. Therefore, the crusher 1 can improve the yield of polycrystalline silicon S and reduce the amount of fine powder generated compared to the crusher 1D.

[0060] [Software implementation example] The functions of the crushing device 1, 1D (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and a program for causing a computer to function as a control block (control unit 60) of the device.

[0061] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program to realize each function described in each of the above embodiments.

[0062] The program may be non-transitory and may be recorded in one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be provided to the device via any wired or wireless transmission medium.

[0063] In addition, some or all of the functions of each of the control blocks can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of each of the control blocks can be realized by, for example, a quantum computer.

[0064] 〔summary〕 A polycrystalline silicon crushing device according to a first aspect of the present invention includes a first member, a second member arranged to face the first member, and a drive unit that drives at least one of the first member and the second member to crush the polycrystalline silicon by sandwiching the polycrystalline silicon between the first member and the second member, and the drive unit drives at least one of the first member and the second member so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less.

[0065] The driving unit drives at least one of the first member and the second member so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less, thereby improving the yield of polycrystalline silicon having a particle size of more than 8 mm and 50 mm or less, and reducing the amount of polycrystalline silicon fine powder having a particle size of 8 mm or less that is generated.

[0066] The polycrystalline silicon crushing device of aspect 2 of the present invention may be the same as in aspect 1, and further include a conveying unit that conveys the polycrystalline silicon from above between the first member and the second member, a first sensor provided above the first member and the second member that detects the distance between the polycrystalline silicon sandwiched between the first member and the second member and the first sensor, and a control unit that controls the driving of the conveying unit based on the detection result of the distance by the first sensor.

[0067] The control unit controls the driving of the transport unit based on the detection result of the first sensor that detects the distance between the polycrystalline silicon sandwiched between the first and second members and the first sensor. This makes it possible to precisely control the amount of polycrystalline silicon sandwiched between the first and second members. Therefore, it is possible to control the amount of polycrystalline silicon sandwiched between the first and second members so as to improve the yield of polycrystalline silicon of a desired size and reduce the amount of polycrystalline silicon fine powder generated.

[0068] The polycrystalline silicon crushing device according to aspect 3 of the present invention may be configured as in aspect 1 or 2, further comprising a housing provided below the first member and the second member and forming a space in which the polycrystalline silicon crushed by the first member and the second member is deposited.

[0069] Since the polycrystalline silicon crushed by the first and second members is deposited in the space formed by the housing, some of the polycrystalline silicon deposited in the housing does not come into contact with the housing. This reduces the contact of the polycrystalline silicon with other members, thereby reducing surface contamination of the polycrystalline silicon.

[0070] The polycrystalline silicon crushing device of aspect 4 of the present invention, in any of aspects 1 to 3, may further include a conveying unit that conveys the polycrystalline silicon from above between the first member and the second member, a second sensor provided inside the housing that detects whether the polycrystalline silicon accumulated inside the housing has reached a predetermined height from a bottom surface of the housing, and a control unit that stops driving the conveying unit when the second sensor detects that the polycrystalline silicon accumulated inside the housing has reached the predetermined height.

[0071] The control unit stops driving the conveying unit when the second sensor detects that the polycrystalline silicon accumulated inside the housing has reached a predetermined height. This makes it possible to prevent polycrystalline silicon from continuing to accumulate inside the housing and to prevent the inside of the housing from being clogged with polycrystalline silicon. It also makes it possible to prevent a part of the polycrystalline silicon from being exposed outside the housing and to prevent the polycrystalline silicon from coming into contact with members outside the housing. This makes it possible to reduce surface contamination of the polycrystalline silicon.

[0072] In the polycrystalline silicon crushing device according to a fifth aspect of the present invention, in any one of the first to fourth aspects, the shortest distance may be a distance between the first member and the second member when they are closest to each other.

[0073] When the first member and the second member are closest to each other, the shortest distance between them is 17 mm or more and 30 mm or less. This makes it possible to further improve the yield of polycrystalline silicon having a particle size of more than 8 mm and 50 mm or less, and to further reduce the amount of fine powder of polycrystalline silicon having a particle size of 8 mm or less that is generated.

[0074] A method for crushing polycrystalline silicon according to a sixth aspect of the present invention includes a feeding step of feeding polycrystalline silicon between a first member and a second member arranged opposite the first member, and a driving step of driving at least one of the first member and the second member to crush the polycrystalline silicon by sandwiching the polycrystalline silicon fed by the feeding step between the first member and the second member, wherein in the driving step, at least one of the first member and the second member is driven so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less.

[0075] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Configurations obtained by appropriately combining multiple technical means disclosed in the embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0076] 1. 1D crushing device 10, 10D First member 20, 20D Second member 30, 30D Drive unit 40 Conveyor 50 First Sensor 60 Control section 80 Case 80a Bottom 83 Second Sensor D1 Shortest interval D2 distance F1 Conveying direction S Polycrystalline silicon SP2 space

Claims

1. A first member; A second member disposed so as to face the first member; a drive unit that drives at least one of the first member and the second member to crush the polycrystalline silicon by sandwiching the polycrystalline silicon between the first member and the second member, The polycrystalline silicon crushing device, characterized in that the driving unit drives at least one of the first member and the second member so that the shortest distance between the first member and the second member is 17 mm or more and 30 mm or less.

2. a transfer unit that transfers the polycrystalline silicon from above between the first member and the second member; a first sensor provided above the first member and the second member, the first sensor detecting a distance between the polycrystalline silicon sandwiched between the first member and the second member and the first sensor; 2. The polycrystalline silicon crushing device according to claim 1, further comprising: a control unit that controls driving of the transport unit based on a detection result of the distance by the first sensor.

3. 2. The polycrystalline silicon crushing device according to claim 1, further comprising a housing provided below the first member and the second member and forming a space in which the polycrystalline silicon crushed by the first member and the second member is accumulated.

4. a transfer unit that transfers the polycrystalline silicon from above between the first member and the second member; a second sensor provided inside the housing, the second sensor detecting whether the polycrystalline silicon deposited inside the housing has reached a predetermined height from a bottom surface of the housing; The polycrystalline silicon crushing device according to claim 3, further comprising a control unit that stops driving the transport unit when the second sensor detects that the polycrystalline silicon accumulated inside the housing has reached the predetermined height.

5. 2. The apparatus for crushing polycrystalline silicon according to claim 1, wherein the shortest distance is a distance between the first member and the second member when they are closest to each other.

6. a step of introducing polycrystalline silicon between a first member and a second member disposed so as to face the first member; a driving step of driving at least one of the first member and the second member to crush the polycrystalline silicon introduced in the introduction step by sandwiching the polycrystalline silicon between the first member and the second member, a driving step of driving at least one of the first member and the second member so that a shortest distance between the first member and the second member is 17 mm or more and 30 mm or less.

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