Fine powder removal device, fine powder removal method, and silicon raw material filling method

Abstract

To provide a fine powder removal device that can properly remove fine powder from inside a charging tube. [Solution] A fine powder removal device for removing fine powder from a charge tube filled with silicon raw material, which has an opening at the lower end that can be opened and closed, comprises a suction nozzle for sucking up the fine powder and a nozzle moving unit for moving the suction nozzle between the inside and outside of the charge tube.

Description

Technical Field

[0001] The present invention relates to a fine powder removing device, a fine powder removing method, and a method for filling a silicon raw material.

Background Art

[0002] Conventionally, when filling a silicon raw material into a charge tube whose lower end opening can be opened and closed, a method for removing fine powder generated during filling is known (see, for example, Patent Document 1). In the method described in Patent Document 1, a raw material charge assist tool is inserted into the opening on the upper end side of the charge tube. An inlet of a vacuum mechanism is set above the raw material charge assist tool. During the filling of the silicon raw material, fine powder of the silicon raw material that rises is sucked through the inlet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method described in Patent Document 1, there is a possibility that fine powder in the charge tube cannot be sucked from the inlet. The fine powder remaining in the charge tube may diffuse into the chamber and adhere to the members in the chamber when charging the silicon raw material from the charge tube into the crucible of the silicon single crystal manufacturing apparatus. The fine powder of the silicon raw material has a property of being difficult to dissolve. Therefore, there is a possibility that the fine powder adhering to the members in the chamber may fall during the growth of the silicon single crystal, causing dislocation and twin defects in the silicon single crystal.

[0005] An object of the present invention is to provide a fine powder removing device, a fine powder removing method, and a method for filling a silicon raw material that can appropriately remove fine powder in a charge tube.

Means for Solving the Problems

[0006] The present invention relates to a fine powder removal device that removes fine powder from a charge tube filled with silicon raw material, the lower end of which is configured to open and close, and comprises a suction nozzle for sucking up the fine powder and a nozzle moving unit for moving the suction nozzle between the inside and outside of the charge tube.

[0007] The present invention relates to a method for removing fine particles from a charge tube filled with silicon raw material, the lower end of which is configured to open and close, and the method comprises a nozzle moving step of moving a suction nozzle into the charge tube and an internal suction step of using the suction nozzle to suction the fine particles from the charge tube.

[0008] The present invention relates to a method for filling a silicon raw material, comprising filling a charge tube having an opening at its lower end that can be opened and closed with the silicon raw material, and comprising: a nozzle moving step of moving a suction nozzle into the charge tube; a filling step of filling the charge tube with the silicon raw material; and an internal suction step of using the suction nozzle to suction fine powder from inside the charge tube. [Brief explanation of the drawing]

[0009] [Figure 1] These are schematic diagrams showing the charge tube and fine powder removal device according to the first and second embodiments. [Figure 2] Block diagram showing the control device for the fine powder removal apparatus according to the first and second embodiments. [Figure 3] This is a flowchart showing the filling process for silicon raw materials according to the first and second embodiments. [Figure 4] This is a flowchart showing the cleaning process according to the first and second embodiments. [Figure 5] This is a schematic diagram showing the cleaning process according to the first and second embodiments. [Figure 6] This is a flowchart showing the filling process according to the first and second embodiments. [Figure 7]This is a flowchart showing the filling process according to the first embodiment. [Figure 8] This is a schematic diagram showing the filling process according to the first embodiment, and it shows the state before the volume of the silicon raw material is leveled. [Figure 9] This is a schematic diagram showing the filling process according to the first embodiment, and it shows the state after the volume of the silicon raw material has been leveled. [Figure 10] This is a flowchart showing the filling process according to the second embodiment. [Modes for carrying out the invention]

[0010] [First Embodiment] <Configuration of the charge tube> A first embodiment of the present invention will be described. The charge tube 9 shown in Figure 1 is used when charging silicon raw material R (see, for example, Figure 8) into the crucible of a silicon single crystal manufacturing apparatus. The charge tube 9 comprises a charge tube body 91, a flange member 92, and an opening / closing member 93.

[0011] The charge tube body 91 is formed in a cylindrical shape from quartz.

[0012] The flange member 92 is made of metal. The flange member 92 includes a flange body 921 fixed to the upper end opening 91A of the charge pipe body 91. The flange body 921 is formed in an annular plate shape with an outer diameter larger than the outer diameter of the charge pipe body 91. The flange body 921 is provided with a support piece 922 extending toward the radial center of the flange body 921. A circular through hole 923 is provided at the tip of the support piece 922. The central axis of the through hole 923 is coaxial with the central axis of the charge pipe body 91.

[0013] The opening / closing member 93 comprises a shaft 931 and a bottom cover 932. The shaft 931 is formed of metal. The shaft 931 is inserted through the through-hole 923 of the flange member 92. The upper end of the shaft 931 is attached to one end of a wire that moves up and down above the crucible. The shaft 931 is covered by a guide tube (not shown) formed in a cylindrical shape of quartz so that the silicon raw material R and the shaft 931 do not come into direct contact. The bottom cover 932 is formed of quartz. The bottom cover 932 is fixed to the lower end of the shaft 931. The bottom cover 932 is formed in a conical shape with the diameter of the bottom surface being not less than the inner diameter of the charge tube body 91.

[0014] <Configuration of the filling system> The fine powder removing device 1 shown in FIG. 1 constitutes a filling system for filling the silicon raw material R into the charge tube 9. The fine powder removing device 1 removes fine powder in the charge tube 9. The fine powder to be removed includes fine powder of silicon and fine powder generated due to breakage or damage of the charge tube body 91 or the bottom cover 932. The fine powder removing device 1 includes an inclination adjusting part 2, a rotating part 3, a blowing part 4, an inner suction part 5, a nozzle moving part 6, an outer suction part 7, and a weighing scale 8. In some cases, each component of the fine powder removing device 1 will be described based on the XYZ coordinate system shown in FIG. 1. The X-axis direction and the Y-axis direction are parallel to the horizontal plane, and the Z-axis direction is parallel to the vertical direction.

[0015] The inclination adjusting part 2 adjusts the inclination of the charge tube 9 with respect to the Z-axis direction. The inclination adjusting part 2 includes a base part 21, a pair of frame parts 22, a rotating shaft body 23, a support body 24, and a tilting motor 25.

[0016] The base part 21 is formed, for example, in a plate shape. The pair of frame parts 22 are provided on the upper surface of the base part 21 so as to be arranged apart in the X-axis direction. Each frame part 22 includes a vertical part 221 extending in the +Z direction (upward) and a horizontal extension part 222 extending in the +Y direction from the upper end of the vertical part 221.

[0017] The rotating shaft 23 is provided so as to bridge the tip ends of a pair of horizontal extensions 222. The rotating shaft 23 is provided so as to be rotatable around its central axis. The support 24 supports the charge tube 9. The support 24 comprises a bottom wall portion 241 facing the lower end of the charge tube 9 and a side wall portion 242 facing the side surface of the charge tube body 91. The bottom wall portion 241 and the side wall portion 242 are formed, for example, in a plate shape and are configured in an L-shape when viewed from the +X direction. The vertical center of the side wall portion 242 on the -Y direction side is fixed to the rotating shaft body 23.

[0018] The tilting motor 25 is fixed, for example, to the horizontal extension 222 on the -X direction side. The rotation axis of the tilting motor 25 is fixed to the -X direction end of the rotation axis body 23. The tilting motor 25 is controlled by a control device 100, which will be described later. With this configuration, when the tilting motor 25 is driven, the rotating shaft 23 rotates, and as the rotating shaft 23 rotates, the tilt of the charge tube 9 supported by the support body 24 with respect to the Z-axis direction is adjusted.

[0019] The tilt adjustment unit 2 does not necessarily have to include a tilt motor 25, or it may further include a tilt motor fixed to the +X direction end of the rotating shaft 23. If the tilt adjustment unit 2 does not include a tilt motor 25, it is preferable that the tilt adjustment unit 2 includes a posture maintenance mechanism that maintains the tilt of the support body 24 in a predetermined state.

[0020] The rotating part 3 rotates the charge tube 9 around its central axis. The rotating part 3 comprises a turntable 31, a housing cylinder 32, a holding part 33, and a rotation guide part 34.

[0021] The turntable 31 rotates around a rotation axis parallel to the Z-axis direction, controlled by the control device 100. The charge tube 9 is placed on the upper surface of the turntable 31 so that the bottom cover 932 is in contact with it. Preferably, the upper surface of the turntable 31 is processed to suppress slippage of the charge tube 9, or a member is provided to suppress slippage, so that the charge tube 9 rotates together with the turntable 31. The housing cylinder 32 is formed in a cylindrical shape with an inner diameter larger than the outer diameter of the charge tube body 91. The housing cylinder 32 is fixed to the upper surface of the turntable 31 such that its central axis coincides with the rotation axis of the turntable 31.

[0022] The retaining portion 33 holds the charging tube 9. The retaining portion 33 comprises a lid portion 331 and a guide projection portion 332. The lid portion 331 is formed in a disc shape and is fixed to the housing cylinder portion 32 so as to close the upper end of the housing cylinder portion 32. A fitting hole 331A into which the charge tube 9 is fitted is provided in the center of the lid portion 331. It is preferable that the inner circumferential surface of the fitting hole 331A is processed to suppress slippage of the charge tube 9, or that a member that suppresses slippage is provided, so that the charge tube 9 rotates together with the holding portion 33 which is fixed to the turntable 31 via the housing cylinder portion 32. The guide projection 332 is formed in a cylindrical shape that extends in the -Z direction from the entire outer edge of the lid portion 331.

[0023] The rotating section 3 may be configured to hold charge tubes 9 that have different lengths in the axial direction of their central axis. For example, a detachable plate-like member may be prepared on the upper surface of the turntable 31, and the plate-like member may be placed on the upper surface of the turntable 31 to match the length of the charge tubes 9. Furthermore, the rotating part 3 may be configured to hold charge tubes 9 with different outer diameters. For example, multiple holding parts 33 with different diameters of fitting holes 331A may be provided, or the holding parts 33 may be provided with a function to change the diameter of the fitting holes 331A.

[0024] The rotating guide portion 34 is fixed to the side wall portion 242 of the support 24 on the +Y direction side. The rotating guide portion 34 is provided with a guide groove 341 into which a part of the guide projection 332 is inserted. The shape of the guide groove 341 when viewed from the +Z direction side is arc-shaped. With this configuration, as the charge tube 9 rotates in conjunction with the rotation of the turntable 31, the rotation of the guide projection 332 is guided by the guide groove 341, thereby stabilizing the rotation of the charge tube 9.

[0025] The discharge unit 4 blows gas A into the charge pipe 9. The discharge unit 4 comprises a discharge nozzle fixing part 41, a holding part 42, a piping housing part 43, first to tenth discharge nozzles 44A to 44J, a gas supply part 45, and first to tenth discharge valves 46A to 46J (see Figure 2). Note that when describing the first to tenth discharge nozzles 44A to 44J collectively, or when describing them without distinction, they may be referred to as discharge nozzles 44. When describing the first to tenth discharge valves 46A to 46J collectively, or when describing them without distinction, they may be referred to as discharge valves 46. The number of discharge nozzles 44 is not particularly limited; it may be nine or fewer, or eleven or more.

[0026] The discharge nozzle fixing portion 41 is formed in a cylindrical shape with one end closed. The axial length of the discharge nozzle fixing portion 41 is longer than the axial length of the charge pipe body 91. The retained portion 42 is formed in a cylindrical shape, with one end connected to the other end of the discharge nozzle fixing portion 41. The retained portion 42 is provided to extend in a direction perpendicular to the axial direction of the discharge nozzle fixing portion 41. The retained portion 42 is held by the nozzle moving portion 6 so that the discharge nozzle fixing portion 41 can be inserted into the charge pipe 9. The pipe housing section 43 is formed in a cylindrical shape, and one end of it is connected to the other end of the holding section 42. Note that the pipe housing section 43 is not required.

[0027] The discharge nozzles 44 are provided on the side surface of the discharge nozzle fixing portion 41, aligned in the axial direction of the discharge nozzle fixing portion 41. The discharge nozzles 44 are arranged in the following order from one end of the discharge nozzle fixing portion 41, that is, the end on which the held portion 42 is not connected: the first discharge nozzle 44A, the second discharge nozzle 44B, the third discharge nozzle 44C, the fourth discharge nozzle 44D, the fifth discharge nozzle 44E, the sixth discharge nozzle 44F, the seventh discharge nozzle 44G, the eighth discharge nozzle 44H, the ninth discharge nozzle 44I, and the tenth discharge nozzle 44J. At least one of the first to tenth discharge nozzles 44A to 44J may be positioned such that its circumferential position on the discharge nozzle fixing portion 41 is different from that of the other discharge nozzles 44.

[0028] The gas supply unit 45 is connected to the first to tenth discharge nozzles 44A to 44J via ten pipes (not shown). These ten pipes are located within the discharge nozzle fixing unit 41, the holding unit 42, and the pipe housing unit 43. The gas supply unit 45 is controlled by the control device 100. The discharge valves 46 are positioned such that the Nth discharge valve is located in the piping connected to the Nth (N is 1 to 10) discharge nozzle. The first to tenth discharge valves 46A to 46J are individually controlled by the control device 100. With this configuration, when the gas supply unit 45 is driven while any of the first to tenth discharge valves 46A to 46J is open, gas A is discharged only from the discharge nozzle 44 corresponding to the opened discharge valve 46, causing fine powder to be stirred up.

[0029] The materials of the discharge nozzle fixing part 41 and the discharge nozzle 44 may be the same or different, but from the viewpoint of preventing fine powder generated by damage or scratches to these parts from mixing into the silicon raw material R, it is preferable that they be quartz or a high-purity resin.

[0030] The inner suction section 5 sucks up fine powder from inside the charge tube 9. The inner suction section 5 comprises a suction nozzle 51, a holding section 52, a pipe 53, and an inner negative pressure generating section 54.

[0031] The suction nozzle 51 is formed in a cylindrical shape with one end closed. The axial length of the suction nozzle 51 is longer than the axial length of the charge tube body 91 of the charge tube 9. Multiple suction holes 511 are provided on the side surface of the suction nozzle 51, arranged in the axial direction. From the same viewpoint as the discharge nozzle fixing part 41, the material of the suction nozzle 51 is preferably quartz or a high-purity resin. The shape of the suction holes 511 is not particularly limited and may be circular, polygonal, or a slit extending in the axial direction. The suction holes 511 may also be provided at different circumferential positions on the suction nozzle 51.

[0032] The held portion 52 is formed in a cylindrical shape, with one end connected to the other end of the suction nozzle 51. The held portion 52 is positioned to extend in a direction perpendicular to the axial direction of the suction nozzle 51. The held portion 52 is held by the nozzle moving portion 6 so that the suction nozzle 51 can be inserted into the charging tube 9.

[0033] One end of the pipe 53 is connected to the other end of the held portion 52. The internal negative pressure generating unit 54 is connected to the other end of the piping 53. The internal negative pressure generating unit 54 is controlled by the control device 100. With this configuration, when the internal negative pressure generating unit 54 is activated, fine powder inside the charge tube 9 is sucked in through each suction port 511. In Figure 1 and other figures, the arrows pointing to each suction port 511 indicate that each suction port 511 is in the process of suction.

[0034] The nozzle moving unit 6 moves the discharge nozzle 44 and the suction nozzle 51 between the inside and outside of the charge pipe 9. The nozzle moving unit 6 comprises a moving and holding unit 61, a moving drive unit 62, and a moving guide unit 63.

[0035] The movable holding part 61 holds the respective held parts 42 and 52 such that the central axes of the discharge nozzle fixing part 41 and the suction nozzle 51 are parallel to the central axis of the charge pipe body 91. The movable holding part 61 has a nut part 611 and a guide hole 612 that pass through the movable holding part 61.

[0036] The mobile drive unit 62 comprises a mobile motor 621, a bearing 622, and a screw shaft 623. The mobile motor 621 is mounted on the side wall 242 such that its motor shaft is parallel to the central axis of the charge tube body 91 and extends away from the charge tube body 91. The mobile motor 621 is controlled by the control device 100. The bearing 622 is located above the moving motor 621 in the side wall portion 242. The screw shaft 623 is connected at one end to the motor shaft and supported at the other end by a bearing 622. The screw shaft 623, together with the nut portion 611, constitutes a ball screw mechanism and is screwed into the nut portion 611.

[0037] The movable guide section 63 includes a guide rod 631 inserted through a guide hole 612 of the movable holding section 61, a lower support section 632 that supports the lower end of the guide rod 631, and an upper support section 633 that supports the upper end of the guide rod 631. The lower support portion 632 and the upper support portion 633 are provided on the side wall portion 242 and support the guide rod 631 so that its central axis is parallel to the central axis of the charge pipe body 91.

[0038] With this configuration, when the moving motor 621 is driven, the moving and holding unit 61 moves while maintaining its straight-line movement by the moving guide unit 63, and as the moving and holding unit 61 moves, the positions of the discharge nozzle 44 and the suction nozzle 51 relative to the charge pipe 9 are adjusted.

[0039] The external suction unit 7 sucks up fine powder near the upper end opening 91A of the charge pipe body 91 on the outside of the charge pipe 9. The external suction unit 7 comprises an external suction body 71, piping 72, and an external negative pressure generating unit 73.

[0040] The external suction body 71 is positioned outside the charge tube 9 when viewed from the +Z direction and is designed to suck up fine powder near the upper end opening 91A. One end of the piping 72 is connected to the external suction body 71. The external negative pressure generating unit 73 is connected to the other end of the piping 72. The external negative pressure generating unit 73 is controlled by the control device 100. With this configuration, when the external negative pressure generating unit 73 is driven, fine powder is sucked in from the external suction body 71. In Figure 1 and other figures, the arrow pointing to the external suction body 71 indicates that the external suction body 71 is in the suction state.

[0041] A tilt adjustment unit 2 is mounted on the weighing scale 8. The weighing scale 8 outputs the weight measurement result to the control device 100.

[0042] The fine powder removal device 1 further comprises a control device 100 shown in Figure 2. The control device 100 includes an input unit 110, a storage unit 120, and a control unit 130.

[0043] The input unit 110 is configured, for example, as a touch panel or physical buttons, and outputs a signal corresponding to the input operation to the control unit 130. The memory unit 120 stores various information necessary for controlling the fine powder removal device 1 so that it can be read by the control unit 130.

[0044] The control unit 130 is equipped with a CPU, and by executing a program stored in the memory unit 120, the CPU functions as a tilt control unit 131, a bulk height estimation unit 132, an insertion position calculation unit 133, a movement control unit 134, a blow-out control unit 135, an internal suction control unit 136, an external suction control unit 137, and a rotation control unit 138.

[0045] The tilt control unit 131 controls the tilt motor 25 to adjust the tilt of the charge tube 9. For example, the tilt control unit 131 adjusts the tilt of the charge tube 9 between an upright state where the central axis of the charge tube 9 is parallel to the Z-axis direction and an inclined state where the central axis of the charge tube 9 is inclined with respect to the Z-axis direction. The angle of the central axis of the charge tube 9 with respect to the Z-axis direction in the inclined state is not particularly limited, but is preferably 30° or more and 60° or less.

[0046] The bulk height estimation unit 132 estimates the bulk height of the silicon raw material R when a predetermined amount of silicon raw material R is filled into the charge tube 9. Details of the method for estimating the bulk height will be described later.

[0047] The insertion position calculation unit 133 calculates the insertion positions of the discharge nozzle 44 and the suction nozzle 51 during cleaning. The insertion positions during cleaning are positions where the discharge nozzle 44 and the suction nozzle 51 do not come into contact with the charge tube 9 when cleaning to remove fine powder from the charge tube 9 that is not filled with silicon raw material R. The insertion position calculation unit 133 calculates the insertion positions of the discharge nozzle 44 and suction nozzle 51 during filling based on the bulk height estimated by the bulk height estimation unit 132. The insertion positions during filling are positions where the discharge nozzle 44 and suction nozzle 51 do not come into contact with the silicon raw material R and the charge pipe 9 during and after filling of the silicon raw material R. Details on how to calculate the insertion position during cleaning and the insertion position during filling will be described later.

[0048] The movement control unit 134 controls the movement motor 621 to move the blow nozzle 44 and the suction nozzle 51 to the insertion position during cleaning or the insertion position during filling.

[0049] The discharge control unit 135 controls the discharge state of gas A at the discharge nozzle 44. Specifically, the discharge control unit 135 selects the discharge nozzles 44 as either driven discharge nozzles 44 that discharge gas A, or non-driven discharge nozzles 44 that do not discharge gas A. Details of the method for selecting driven or non-driven discharge nozzles 44 will be described later. The discharge control unit 135 opens the discharge valve 46 corresponding to the discharge nozzle 44 to be driven and closes the discharge valve 46 corresponding to the discharge nozzle 44 that is not driven. The discharge control unit 135 controls the gas supply unit 45 to discharge gas A from the discharge nozzle 44 to be driven.

[0050] The internal suction control unit 136 controls the internal negative pressure generation unit 54 to suck up the fine powder inside the charge tube 9 with the suction nozzle 51.

[0051] The external suction control unit 137 controls the external negative pressure generating unit 73 to use the external suction body 71 to suck up fine powder near the upper end opening 91A outside the charge tube 9.

[0052] The rotation control unit 138 controls the turntable 31 to rotate the charge tube 9 by the angle set for cleaning or the angle set for filling. The angle set for cleaning and the angle set for filling may be the same or different. The angle set for cleaning and the angle set for filling are not particularly limited, but are preferably between 45° and 120°.

[0053] The filling system further includes a raw material feeder 200 (see Figure 8). The raw material feeder 200 fills the charge tube 9 with a specified amount of silicon raw material R in one or multiple stages.

[0054] <Filling process for silicon raw materials> This section describes the filling process for silicon raw material R. As shown in Figure 3, the filling process for silicon raw material R comprises a cleaning process S1 using a fine powder removal method and a filling process S2 using a silicon raw material R filling method.

[0055] In cleaning process S1, when an operator or conveying device holds the charge tube 9, which is not filled with silicon raw material R, in the housing cylinder portion 32 and holding portion 33 of the rotating unit 3, the tilt control unit 131 controls the tilt motor 25 to make the charge tube 9 stand upright, as shown in Figures 4 and 5 (step S11). Note that if the charge tube 9 is already in an upright position while being held in the rotating unit 3 by the operator or conveying device, the process in step S11 is unnecessary.

[0056] The insertion position calculation unit 133 calculates the insertion position during cleaning (step S12). In step S12, the insertion position calculation unit 133 acquires the shape of the charge pipe 9, for example, input by an operator using the input unit 110. The shape of the charge pipe 9 includes the shape of the charge pipe body 91 and the opening / closing member 93. Based on the shape of the charge pipe 9, the insertion position calculation unit 133 calculates a position where the discharge nozzle 44 and suction nozzle 51 do not contact the charge pipe 9, and where the distance from the lower end of the discharge nozzle 44 and suction nozzle 51 to the bottom cover 932 is greater than or equal to a first lower limit and less than or equal to a first upper limit, as the insertion position during cleaning. From the viewpoint of cleaning the entire inside of the charge pipe 9, it is preferable that the distance to the bottom cover 932 is as short as possible at the insertion position during cleaning.

[0057] The discharge control unit 135 selects the discharge nozzles 44 to be driven and the discharge nozzles 44 not to be driven based on the insertion position during cleaning (step S13). In step S13, the discharge control unit 135 calculates the distance from the discharge nozzle 44 located at the insertion position during cleaning to the upper end of the flange member 92, i.e., the upper end of the charge pipe 9, based on the shape of the charge pipe 9 and its insertion position during cleaning. The discharge control unit 135 selects the discharge nozzle 44 located inside the charge pipe body 91 and whose distance from the upper end of the charge pipe 9 is greater than or equal to the first threshold distance T1 as the discharge nozzle 44 to be driven, and selects the other discharge nozzles 44 as the discharge nozzles 44 not to be driven. The first threshold distance T1 is the distance at which fine powder stirred up by gas A from the discharge nozzle 44 to be driven, located at the uppermost position inside the charge pipe 9, does not scatter outside the charge pipe 9, and is set to, for example, 100 mm or more and 150 mm or less. In the first embodiment, as shown in Figure 5, the distance L10 from the 10th discharge nozzle 44J located at the top of the charge pipe 9 to the top end of the charge pipe 9 is less than the first threshold distance T1, and the distance L9 from the 9th discharge nozzle 44I, the second from the top, to the top end of the charge pipe 9 is greater than or equal to the first threshold distance T1. Therefore, the 1st to 9th discharge nozzles 44A to 44I are selected as the discharge nozzles 44 to be driven.

[0058] The movement control unit 134 controls the movement motor 621 to lower the blowing nozzle 44 and the suction nozzle 51 from the standby position above the charging pipe 9 to the insertion position for cleaning (step S14: nozzle movement process).

[0059] The internal suction control unit 136 drives the internal negative pressure generation unit 54 to start suction from the suction nozzle 51, as shown by the solid arrow in Figure 5 (Step S15: Internal suction process).

[0060] The discharge control unit 135 controls the opening and closing state of the discharge valve 46 and then drives the gas supply unit 45 to start the discharge of gas A from only the discharge nozzle 44 to be driven, as shown by the solid arrows in Figure 5 (Step S16: Discharge process). In the first embodiment, in step S16, the discharge control unit 135 starts discharging gas A from the first to ninth discharge nozzles 44A to 44I. The fine powder inside the charge pipe 9 is stirred up by the discharged gas A and sucked up by the suction nozzle 51.

[0061] The rotation control unit 138 controls the turntable 31 to rotate the charge tube 9 by the set angle during cleaning (step S17). With the above steps completed, cleaning process S1 is finished.

[0062] In the filling process S2, while suction by the suction nozzle 51 and blowing of gas A by the driven blow nozzle 44 are continuing, the tilt control unit 131 controls the tilt motor 25 to tilt the charge tube 9, as shown in Figures 6 and 8 (Step S21: tilting process).

[0063] The external suction control unit 137 drives the external negative pressure generating unit 73 to start suction by the external suction body 71 near the upper end opening 91A outside the charge pipe 9, as shown by the solid arrows in Figure 8 (Step S22: External suction step).

[0064] The bulk estimation unit 132 obtains the planned amount of silicon raw material R to be filled next time (step S23). In the first embodiment, a predetermined amount of silicon raw material R is filled at least once by the raw material feeder 200 shown in Figure 8. In step S23, the bulk estimation unit 132 obtains the planned amount of silicon raw material R to be filled from the control device of the raw material feeder 200. The filling of the silicon raw material R may be done manually by an operator. When the filling of the silicon raw material R is done by a raw material feeder 200 or manually, the bulk height estimation unit 132 may obtain the planned filling amount entered by the operator using the input unit 110.

[0065] The bulk height estimation unit 132 estimates the bulk height of the silicon raw material R when the amount of silicon raw material R to be filled, as obtained in step S23, is filled into the charge tube 9 (step S24: bulk height estimation step). In step S24, the bulk height estimation unit 132 estimates the bulk height based on the shape and inclination angle of the charge tube 9, the amount of silicon raw material R already filled, and the planned filling amount. Furthermore, if the amount of silicon raw material R is obtained by weight, the bulk can be estimated by converting the weight to volume.

[0066] The insertion position calculation unit 133 calculates the insertion position during filling (step S25). In step S25, the insertion position calculation unit 133 calculates the insertion position during filling based on the height of the volume estimated in step S24, such that the blowing nozzle 44 and the suction nozzle 51 do not come into contact with the charge tube 9, and the distance from the lower ends of the blowing nozzle 44 and the suction nozzle 51 to the height of the volume is greater than or equal to a second lower limit and less than or equal to a second upper limit. From the viewpoint of stirring up and sucking up the fine powder throughout the charge tube 9, it is preferable that the distance to the height of the volume is as short as possible at the insertion position during filling. Furthermore, at least one of the second lower limit and the second upper limit may be the same as or different from the first lower limit or first upper limit used to calculate the insertion position during cleaning.

[0067] The discharge control unit 135 selects the discharge nozzles 44 to be driven and the discharge nozzles 44 not to be driven based on the insertion position during filling (step S26). In step S26, the discharge control unit 135 calculates the distance from the discharge nozzle 44 located at the insertion position during filling to the upper end of the charge pipe 9, based on the shape of the charge pipe 9 and its insertion position during filling. The discharge control unit 135 selects the discharge nozzle 44 located inside the charge pipe 9 and whose distance from the upper end of the charge pipe 9 is greater than or equal to the second threshold distance T2 as the discharge nozzle 44 to be driven, and selects the other discharge nozzles 44 as the discharge nozzles 44 not to be driven. The second threshold distance T2 is the distance at which fine powder stirred up by gas A from the discharge nozzle 44 located at the uppermost position inside the charge pipe 9 does not scatter outside the charge pipe 9, and is set, for example, to 100 mm or more and 150 mm or less. In the first embodiment, as shown in Figure 8, the distance L8 from the eighth discharge nozzle 44H located at the top of the charge pipe 9 to the top end of the charge pipe 9 is less than the second threshold distance T2, and the distance L7 from the seventh discharge nozzle 44G, the second from the top, to the top end of the charge pipe 9 is greater than or equal to the second threshold distance T2. Therefore, the first to seventh discharge nozzles 44A to 44G are selected as the discharge nozzles 44 to be driven. The second threshold distance T2 may be the same distance as the first threshold distance T1, or it may be a different distance.

[0068] The discharge control unit 135 controls the opening and closing state of the discharge valve 46 to start the discharge of gas A from only the discharge nozzle 44 to be driven, as shown by the solid arrow in Figure 8 (Step S27: Discharge process). In the first embodiment, in step S27, the discharge control unit 135 stops the discharge of gas A from the 8th and 9th discharge nozzles 44H and 44I so that gas A is discharged only from the 1st to 7th discharge nozzles 44A to 44G, from a state in which gas A is being discharged from the 1st to 9th discharge nozzles 44A to 44I.

[0069] The movement control unit 134 controls the movement motor 621 to raise the blowing nozzle 44 and the suction nozzle 51 from the insertion position during cleaning to the insertion position during filling (step S28).

[0070] As shown in Figures 7 and 8, the raw material feeder 200 fills the charge pipe 9 with the planned amount of silicon raw material R (step S29: filling process). The fine powder generated by the filling of the silicon raw material R is stirred up by the blown-out gas A and sucked up by the suction nozzle 51. Note that in Figures 8 and 9, the silicon raw material R is shown as an ellipsoid for convenience, but in reality it is not a perfect ellipsoid, but rather a granular raw material formed by crushing polycrystalline silicon raw material rods. Also, as mentioned above, the filling of the planned amount may be done manually.

[0071] The rotation control unit 138 determines whether or not the filling of the planned amount of silicon raw material R has been completed (step S30: filling completion determination step). In step S30, the rotation control unit 138 determines that filling is not complete if the measurement result of the weighing scale 8 continues to change, and determines that filling is complete when the measurement result stops changing.

[0072] If the rotation control unit 138 determines NO in step S30, it performs the process of step S30 after a predetermined time has elapsed. If the rotation control unit 138 determines YES in step S30, it waits for a set time (step S31). During filling of the silicon raw material R, fine particles adhering to the silicon raw material R and fine particles that enter the charge tube 9 together with the silicon raw material R are stirred up by the gas A from the blow nozzle 44 and sucked up by the suction nozzle 51. Even after the filling of the silicon raw material R is completed, the stirring up and sucking up of fine particles continues for a while. The set time is set to the time it is estimated that all the fine particles in the charge tube 9 have been sucked up by the suction nozzle 51. If the set time is too short, fine particles may remain in the charge tube 9, and if it is too long, the filling efficiency will be poor, so it is set, for example, between 5 seconds and 120 seconds.

[0073] The rotation control unit 138 determines whether or not to perform additional filling after the set waiting time has ended (step S32). If the rotation control unit 138 determines YES in step S32, that is, if it determines that the specified amount of silicon raw material R has not been filled, it controls the turntable 31 to rotate the charge tube 9 by the angle set during filling, thereby leveling the volume of silicon raw material R from the state shown by the solid line in Figure 8 to the state shown by the solid line in Figure 9 (step S33: leveling process). Once step S33 is completed, as shown in Figure 6, the bulk estimation unit 132 obtains the planned amount of silicon raw material R to be filled next time (step S23).

[0074] If the rotation control unit 138 determines NO in step S32, that is, if it determines that the specified amount of silicon raw material R has been filled, the tilt control unit 131 controls the tilt motor 25 to make the charge tube 9 stand upright, as shown in Figure 7 (step S34).

[0075] The discharge control unit 135 stops the gas supply unit 45 and stops the discharge of gas A from the discharge nozzle 44 to be driven (step S35). The internal suction control unit 136 stops the internal negative pressure generation unit 54 and stops suction from the suction nozzle 51 (step S36). The external suction control unit 137 stops the external negative pressure generation unit 73 and stops suction from the external suction body 71 (step S37). The movement control unit 134 controls the movement motor 621 to raise the discharge nozzle 44 and the suction nozzle 51 from the insertion position during filling to the standby position (step S38).

[0076] <Effects of the First Embodiment> The fine powder removal device 1 includes a suction nozzle 51 for sucking up fine powder, and a nozzle moving unit 6 for moving the suction nozzle 51 between the inside and outside of the charge tube 9. Therefore, in the cleaning process S1 and the filling process S2, after moving the suction nozzle 51 into the inside of the charging tube 9, suction is performed using the suction nozzle 51 to properly remove fine powder from inside the charging tube 9.

[0077] The fine powder removal device 1 further includes a blowing nozzle 44 that blows out gas A. The nozzle moving unit 6 moves the blowing nozzle 44 between the inside and outside of the charge pipe 9. Therefore, in the cleaning process S1 and the filling process S2, after moving the blow nozzle 44 into the inside of the charge tube 9, gas A is blown out from the blow nozzle 44, forcibly stirring up the fine powder adhering to the charge tube 9 and the silicon raw material R, and the stirred-up fine powder can be sucked up by the suction nozzle 51. Thus, a larger amount of fine powder can be removed efficiently.

[0078] The fine powder removal device 1 includes a tilt adjustment unit 2 that tilts the charging tube 9 and a rotating unit 3 that rotates the charging tube 9. Therefore, in the filling process S2, the process of filling the inclined charging tube 9 with silicon raw material R and the process of rotating the charging tube 9 by a set angle during filling to level the volume of silicon raw material R can be carried out until a specified amount of silicon raw material R is filled. Thus, silicon raw material R can be filled more efficiently by a simple method of just rotating the charging tube 9. During the cleaning process S1 and the filling process S2, the charging tube 9 can be rotated while gas A is being blown out from the blowing nozzle 44 and while suction is being drawn in from the suction nozzle 51, allowing for more efficient removal of fine powder.

[0079] The fine powder removal device 1 waits for a set time after the planned amount of silicon raw material R has been filled, and then levels the volume of the silicon raw material R. Therefore, any remaining fine powder after filling can be removed during the set waiting time, and the volume of the silicon raw material R can be leveled. This leveling process prevents the remaining fine powder from getting into the gaps between the silicon raw material R.

[0080] The fine powder removal device 1 estimates the volume of the silicon raw material R when the planned amount of silicon raw material R is filled, before filling the device with the planned amount of silicon raw material R. Based on this estimation, it moves the suction nozzle 51 and the blowing nozzle 44 to the insertion position during filling. Therefore, contact between the silicon raw material R and the suction nozzle 51 or blow nozzle 44 can be suppressed during and after filling of the silicon raw material R, thereby suppressing the generation of fine silicon powder due to such contact. Furthermore, since the insertion position during filling is calculated based on the height of the material estimated based on the planned filling amount, contact between the silicon raw material R and the suction nozzle 51 or blow nozzle 44 can be reliably suppressed.

[0081] The fine powder removal device 1 selects, from among the discharge nozzles 44 located at the insertion position during filling, the discharge nozzle 44 located inside the charge pipe 9 as the discharge nozzle 44 to be driven for discharging gas A, and the discharge nozzle 44 located outside the charge pipe 9 as the discharge nozzle 44 that does not discharge gas A. In this way, by not blowing out gas A from the discharge nozzle 44 located outside the charge tube 9, it is possible to suppress the intake of fine powder from outside the charge tube 9 into the charge tube 9.

[0082] The fine powder removal device 1 selects, from among the discharge nozzles 44 located at the insertion position during filling, the discharge nozzle 44 located inside the charge pipe 9 and whose distance from the upper end of the charge pipe 9 is 2 or more than the second threshold distance T2 as the discharge nozzle 44 to be driven, and selects the other discharge nozzles 44 as the discharge nozzles 44 not to be driven. In this way, even if the discharge nozzle 44 is located inside the charge tube 9, by not discharging gas A from the discharge nozzle 44 whose distance from the upper end of the charge tube 9 is less than the second threshold distance T2, it is possible to suppress the scattering of fine powder inside the charge tube 9 outside the charge tube 9.

[0083] The fine powder removal device 1 is provided on the outside of the charge tube 9 and further includes an external suction body 71 that sucks up fine powder near the upper end of the charge tube 9. Therefore, fine particles moving from the inside to the outside of the charge tube 9, and fine particles moving from the outside to the inside of the charge tube 9, can be removed.

[0084] [Second Embodiment] A second embodiment of the present invention will now be described. Furthermore, components identical to those in the first embodiment will be given the same names and reference numerals, and their descriptions will be simplified or omitted.

[0085] <Configuration of the filling system> As shown in Figures 1 and 2, the fine powder removal device 1A constituting the filling system has the same configuration as the fine powder removal device 1 of the first embodiment, except that the configuration of the control device 100A differs from that of the control device 100. The control device 100A has the same configuration as the control device 100 of the first embodiment, except that the tilt control unit 131A and the rotation control unit 138A are different from the tilt control unit 131 or the rotation control unit 138. The tilt control unit 131A adjusts the tilt of the charge tube 9 at a different timing than the tilt control unit 131 in the first embodiment. The rotation control unit 138A differs from the rotation control unit 138 of the first embodiment in that it rotates the charge tube 9 by a set angle during cleaning, but does not rotate it by a set angle during filling.

[0086] <Filling process for silicon raw materials> This section describes the filling process for silicon raw material R. As shown in Figure 3, the filling process of the silicon raw material R differs from the filling process S2 of the first embodiment in that the filling process S3 using the silicon raw material R filling method is different. In filling process S3, the control device 100A performs the processes of steps S21 to S29 of filling process S2, as shown in Figures 6 and 10.

[0087] When the filling process of silicon raw material R in step S29 is performed, the tilt control unit 131A determines whether or not the filling of the planned amount of silicon raw material R has been completed (step S41). The determination criteria in step S41 are the same as the determination criteria in step S30 of the first embodiment.

[0088] If the tilt control unit 131A determines NO in step S41, it performs the process of step S41 after a predetermined time has elapsed. If the tilt control unit 131A determines YES in step S41, it waits for a set time (step S42). The waiting time in step S42 is the same as, for example, the waiting time in step S31 of the first embodiment.

[0089] When the set waiting time is over, the tilt control unit 131A controls the tilt motor 25 to bring the charge tube 9 to an upright position, thereby leveling the volume of the silicon raw material R (step S43).

[0090] The tilt control unit 131A determines whether or not to perform additional filling (step S44). If the tilt control unit 131A determines YES in step S44, it controls the tilt motor 25 to tilt the charge tube 9 (step S45). Once step S45 is completed, as shown in Figure 6, the bulk estimation unit 132 obtains the planned amount of silicon raw material R to be filled next time (step S23).

[0091] If the tilt control unit 131A determines NO in step S44, the control device 100A performs the processing in steps S35 to S38.

[0092] <Effects of the second embodiment> According to the second embodiment, in addition to the same effects as the first embodiment, the following effects can be achieved. In the filling process S3, the fine powder removal device 1A performs the following steps: filling the inclined charge tube 9 with silicon raw material R, and then raising the charge tube 9 to an upright position to level the volume of silicon raw material R, until a specified amount of silicon raw material R is filled. Therefore, the silicon raw material R can be filled more efficiently by simply adjusting the tilt of the charging tube 9.

[0093] [Differentiation] The fine powder removal device 1,1A does not necessarily have to include at least one of the blowing section 4 and the outer suction section 7. The fine powder removal device 1 does not necessarily have to include at least the tilt adjustment unit 2 of the tilt adjustment unit 2 and the rotating unit 3. Even if the fine powder removal device 1 has a rotating unit 3 but does not have a tilt adjustment unit 2, the volume of the silicon raw material R can be leveled by filling the charge tube 9 with the planned amount of silicon raw material R in an upright position and then rotating the charge tube 9 by the angle set at the time of filling. The fine powder removal device 1A does not need to be equipped with a tilt adjustment unit 2.

[0094] The fine powder removal device 1,1A does not need to have a function to estimate the bulk height of the silicon raw material R and calculate the insertion position during filling based on the estimation result. In this case, for each filling of the planned amount of silicon raw material R, the suction nozzle 51 and the blow nozzle 44 may be moved to a predetermined position regardless of the planned amount, or they may not be moved. In such configurations, the suction nozzle 51 and the blow nozzle 44 may come into contact with the silicon raw material R, potentially generating fine particles of the silicon raw material R, but these generated fine particles can be appropriately removed by the suction nozzle 51 inside the charge tube 9.

[0095] After the planned amount of silicon raw material R has been filled, a process to level the volume of the silicon raw material R may be performed immediately.

[0096] Gas A may be blown out from all discharge nozzles 44 regardless of whether they are located inside the charge pipe 9, or gas A may be blown out from all discharge nozzles 44 located inside the charge pipe 9 regardless of their distance from the upper end of the charge pipe 9.

[0097] A ball screw mechanism comprising a nut portion 611 and a screw shaft 623 was used to move the suction nozzle 51 and the discharge nozzle 44, but an electro-pneumatic actuator or a cylinder mechanism may also be used. Alternatively, instead of the discharge nozzle 44, a slit may be provided in the discharge nozzle fixing part 41, and the discharge nozzle fixing part 41 with the slit may function as the discharge nozzle. The determination of whether or not the planned amount of silicon raw material R has been filled was made based on the measurement results of the weighing scale 8, but it may also be made based on the imaging results of the imaging unit that images the charging tube 9. During the filling of the planned amount of silicon raw material R, the change in the bulk height of the silicon raw material R may be estimated based on the measurement results of the weighing scale 8 and the imaging results of the imaging unit, and based on the change in bulk height, the suction nozzle 51 and the blowing nozzle 44 may be raised continuously or intermittently so as not to come into contact with the silicon raw material R. The processes performed by control devices 100 and 100A may also be performed by an operator. [Explanation of symbols]

[0098] 1,1A...Fine powder removal device, 2...Tilt adjustment unit, 3...Rotation unit, 6...Nozzle movement unit, 9...Charging pipe, 44...Blow-out nozzle, 51...Suction nozzle, 71...Outer suction unit, 132...Bulk height estimation unit, 135...Blow-out control unit, A...Gas, S14...Nozzle movement process, S15...Inner suction process, S16,S27...Blow-out process, S21...Tilt process, S22...Outer suction process, S24...Bulk height estimation process, S29...Filling process, S30,S41...Filling completion determination process, S33,S43...Leveling process.

Claims

1. A fine powder removal device having a lower opening that can be opened and closed, for removing fine powder from a charge tube filled with silicon raw material, A suction nozzle for aspirating the aforementioned fine powder, A fine powder removal device comprising a nozzle moving unit for moving the suction nozzle between the inside and outside of the charging tube.

2. In the fine powder removal device according to claim 1, It is further equipped with a nozzle that blows out gas, The nozzle moving section is a fine powder removal device that moves the blowing nozzle between the inside and outside of the charge pipe.

3. In the fine powder removal device according to claim 1, A fine powder removal device further comprising a tilt adjustment unit for adjusting the inclination of the charge tube with respect to the vertical direction.

4. In the fine powder removal device according to claim 3, A fine powder removal device further comprising a rotating part for rotating the charge tube around its central axis.

5. In the fine powder removal device according to claim 1, The device further includes a bulk estimation unit that estimates the bulk height of the silicon raw material when a predetermined amount of the silicon raw material is filled into the charge tube, before filling the charge tube with the predetermined amount of the silicon raw material. The nozzle moving unit is a fine powder removal device that, based on the estimated height of the bulk, moves the suction nozzle to a filling insertion position that does not come into contact with the silicon raw material during and after filling of a predetermined amount of silicon raw material.

6. In the fine powder removal device according to claim 2, The device further includes a bulk estimation unit that estimates the bulk height of the silicon raw material when a predetermined amount of the silicon raw material is filled into the charge tube, before filling the charge tube with the predetermined amount of the silicon raw material. The nozzle moving unit is a fine powder removal device that, based on the estimated height of the bulk, moves the suction nozzle and the blowing nozzle to a filling insertion position that does not come into contact with the predetermined amount of silicon raw material during and after filling.

7. In the fine powder removal device according to claim 6, A plurality of the discharge nozzles are arranged so as to be aligned in the central axis direction of the charge pipe, The system further comprises a blowing control unit that controls the plurality of blowing nozzles, The blowing control unit is a fine powder removal device that, when the plurality of blowing nozzles move to the insertion position during filling, blows out the gas from the blowing nozzles located inside the charging pipe, and does not blow out the gas from the blowing nozzles located outside the charging pipe.

8. In the fine powder removal device according to claim 1, A fine powder removal device further comprising an external suction body for sucking up the fine powder near the upper end of the charge tube on the outside of the charge tube.

9. A method for removing fine powder from a charge tube filled with silicon raw material, wherein the lower end opening is configured to be openable and closable, A nozzle movement step of moving the suction nozzle into the charging tube, A method for removing fine powder, comprising an internal suction step of sucking the fine powder from inside the charge tube with the suction nozzle.

10. In the fine powder removal method described in claim 9, The process further includes a blowing step in which gas is blown from the blowing nozzle into the charging tube after the nozzle movement step has been performed, thereby causing the fine powder to become airborne. The nozzle movement step is a method for removing fine powder, which involves moving the discharge nozzle into the charge pipe.

11. A method for filling a silicon raw material into a charge tube whose lower end opening is configured to be openable and closable, A nozzle movement step of moving the suction nozzle into the charging tube, A filling step of filling the charge tube with the silicon raw material, A method for filling a silicon raw material, comprising an internal suction step of using the suction nozzle to suction fine powder from inside the charging tube.

12. In the method for filling silicon raw materials according to claim 11, The process further includes a blowing step in which gas is blown into the charge tube from a blowing nozzle, thereby causing the fine powder to become airborne. The nozzle movement step is a method for filling a silicon raw material, wherein the nozzle movement step is moved into the charge pipe before the blowing step is performed.

13. In the method for filling silicon raw materials according to claim 11, The charging pipe is tilted from a state in which its central axis is parallel to the vertical direction, The filling step involves filling the charge tube, which is inclined with respect to the vertical direction, with a predetermined amount of the silicon raw material. A method for filling a silicon raw material, comprising: a leveling step of leveling the volume of the silicon raw material by rotating the charge tube around the central axis of the charge tube; and repeating this until a specified amount of the silicon raw material is filled into the charge tube.

14. In the method for filling silicon raw materials according to claim 11, The charging pipe is tilted from a state in which its central axis is parallel to the vertical direction, The filling step involves filling the charge tube, which is inclined with respect to the vertical direction, with a predetermined amount of the silicon raw material. A method for filling a silicon raw material, comprising: a leveling step of leveling the volume of the silicon raw material by returning the charge tube to a state in which the central axis is parallel to the vertical direction, and repeating this until a specified amount of the silicon raw material is filled into the charge tube.

15. In the method for filling silicon raw materials according to claim 13 or claim 14, The process further includes a filling completion determination step for determining whether or not the filling of a predetermined amount of silicon raw material in the filling step has been completed, The method for filling a silicon raw material, wherein the leveling step is performed after a set time has elapsed since it has been determined that the filling of a predetermined amount of silicon raw material has been completed, and the volume of the silicon raw material is leveled.

16. In the method for filling silicon raw materials according to claim 11, The process further includes a bulk estimation step of estimating the bulk height of the silicon raw material when a predetermined amount of the silicon raw material is filled into the charge tube, before filling the charge tube with a predetermined amount of the silicon raw material. A method for filling a silicon raw material, wherein the nozzle movement step involves moving the suction nozzle to a filling insertion position that does not come into contact with the silicon raw material, based on the estimated height of the volume.

17. In the method for filling silicon raw materials according to claim 12, The process further includes a bulk estimation step of estimating the bulk height of the silicon raw material when a predetermined amount of the silicon raw material is filled into the charge tube, before filling the charge tube with a predetermined amount of the silicon raw material. The nozzle movement step is a method for filling a silicone raw material, wherein, based on the estimation result of the bulk height, the suction nozzle and the blowing nozzle are moved to a filling insertion position where they do not come into contact with the silicone raw material.

18. In the method for filling silicon raw materials according to claim 17, The blowing step is a method for filling a silicon raw material, wherein when a plurality of blowing nozzles arranged in line along the central axis of the charge tube move to the insertion position during filling, the gas is blown out from the blowing nozzles located inside the charge tube, and the gas is not blown out from the blowing nozzles located outside the charge tube.

19. In the method for filling silicon raw materials according to claim 18, The blowing step is a method for filling a silicon raw material, wherein when the plurality of blowing nozzles move to the insertion position during filling, the gas is blown out from the blowing nozzles located at a distance greater than or equal to a threshold distance from the upper end of the charge tube within the charge tube, and the gas is not blown out from the blowing nozzles located at a distance less than the threshold distance.

20. In the method for filling silicon raw materials according to claim 18, A method for filling a silicon raw material, further comprising an external suction step of using an external suction body provided on the outside of the charge tube to suction the fine powder near the upper end of the charge tube.

Images