Silica powder filtering system

Abstract

The utility model provides a silicon powder filtering system and relates to the technical field of polycrystalline silicon. The device comprises a precision filter, a feeding pipeline, a discharging pipeline and a pollution discharge pipeline are respectively communicated with the side part, the top and the bottom of the precision filter, the discharging pipeline is communicated with a backwashing pipeline, and the bottom of the precision filter is communicated with a bubbling pipeline. According to the utility model, silicon powder attached to the surface of the filter element can be thoroughly washed away.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon, in particular to a silicon powder filtering system. Background Art

[0002] Polycrystalline silicon is a form of elemental silicon. When molten silicon solidifies under supercooled conditions, silicon atoms arrange themselves into numerous nuclei in a diamond lattice. These nuclei grow into grains with varying crystal orientations, which then combine to form polycrystalline silicon. Polycrystalline silicon exhibits semiconductor properties and is an extremely important and high-quality semiconductor material.

[0003] The amorphous silicon powder produced during polysilicon production must be filtered through a silicon powder filter. After a certain filtration cycle, filter cake forms on the filter element, necessitating the filter to be removed from the system for backwashing. During backwashing, the filter typically only has one large zone. Due to its large size, backwashing often results in incomplete backwashing. Furthermore, microsilica adheres to the filter element surface and is difficult to remove, resulting in poor backwashing effectiveness and a short filter operating cycle. Utility Model Content

[0004] The purpose of the utility model is to develop a silicon powder filtering system which can completely wash away the silicon powder attached to the surface of the filter element.

[0005] The utility model is achieved through the following technical solutions:

[0006] A silicon powder filtration system, comprising:

[0007] precision filters;

[0008] The feed pipeline, the discharge pipeline and the sewage pipeline are connected to the side, the top and the bottom of the precision filter respectively;

[0009] Among them, the discharge pipeline is connected to a backwash pipeline, and the bottom of the precision filter is connected to a bubbling pipeline.

[0010] Optionally, the top of the precision filter is connected to a delivery pipe, the delivery pipe is connected to a connecting pipe, and valves are provided on the discharge pipeline and the backwash pipeline and are respectively connected to the connecting pipe.

[0011] Optionally, the backwash pipeline is connected to an air inlet pipe, and a valve is provided on the air inlet pipe.

[0012] Optionally, the discharge pipeline includes a discharge main pipe, which is connected to a connecting pipe. In the direction away from the connecting pipe, the discharge main pipe is sequentially connected to a vent pipe and a discharge pipe, and both the vent pipe and the discharge pipe are provided with valves.

[0013] Optionally, a material reverse arch pipe is connected to the main discharge pipe on the side of the discharge pipe away from the vent pipe, and a valve is provided on the material reverse arch pipe.

[0014] Optionally, a plurality of filter elements are provided in the middle of the precision filter, a partition is provided on the upper part of the precision filter, and a plurality of filter elements are provided at the bottom of the partition.

[0015] Optionally, two crossed and connected baffles are provided in the precision filter above the partition, and the two baffles cross to divide the space above the partition into four discharge cavities. The precision filter is provided with four delivery pipes respectively connected to the four discharge cavities, and the four delivery pipes are connected to the connecting pipe.

[0016] Optionally, the internal cross-section of the precision filter is circular, the two baffles are vertically arranged, and the two baffles are arranged along the radial direction of the cross-section of the precision filter. The two baffles evenly divide the upper space of the partition into four discharge cavities.

[0017] The beneficial effects of the utility model are:

[0018] The utility model is provided with a bubbling pipeline, and nitrogen is bubbled into the precision filter before backwashing, so that the silicon powder on the surface of the filter element falls off or loosens, and the silicon powder is prevented from being tightly adhered to the surface of the filter element and being difficult to be washed away by the backwashing liquid. The baffle is used to separate the four discharge chambers to realize the partitioning of the interior of the precision filter. When backwashing is performed, each discharge chamber, that is, each partition, is independently input with backwashing liquid by a delivery pipe, so that the backwashing effect of the filter element in each partition is improved and the flushing is thorough, the silicon powder on the surface of the filter element is completely washed away, and the operation cycle of the precision filter is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 This is the PID diagram of the present utility model;

[0021] Figure 2 This is the internal structure diagram of the precision filter;

[0022] Figure 3 This is the top structure diagram of the precision filter.

[0023] Figure numerals: 1, precision filter; 101, partition; 102, filter element; 103, baffle; 2, feed pipeline; 3, sewage pipeline; 4, bubbling pipeline; 5, conveying pipe; 6, connecting pipe; 7, backwash pipeline; 8, air inlet pipe; 9, discharge main pipe; 10, vent pipe; 11, discharge pipe; 12, material anti-arch pipe. DETAILED DESCRIPTION

[0024] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] like Figures 1-3 As shown, the utility model discloses a silicon powder filtration system, comprising a precision filter 1, wherein the side of the precision filter 1 is connected to a feed pipeline 2, and the bottom is connected to a sewage pipeline 3.

[0028] The precision filter 1 has a circular internal cross-section, with multiple filter elements 102 located in the middle. A partition 101 is located above the precision filter 1, with multiple filter elements 102 located at the bottom of the partition 101. Two intersecting and connected baffles 103 are located within the precision filter 1 above the partition 101. The two baffles 103 are vertically arranged and radially arranged along the cross-section of the precision filter 1. The two baffles 103 intersect to evenly divide the space above the partition 101 into four discharge chambers.

[0029] Each discharge cavity is connected with a delivery pipe 5, and the four delivery pipes 5 are connected with a connecting pipe 6. One end of the connecting pipe 6 is connected with a backwash pipeline 7, and the other end of the connecting pipe 6 is connected with a discharge pipeline.

[0030] A valve is provided on the backwash line 7, which is closed during discharging and opened during backwashing. The backwash line 7 can transport backwash liquid to the connecting pipe 6. The backwash line 7 is also connected to an air inlet pipe 8, which is provided with a valve. The air inlet pipe 8 can input nitrogen into the backwash line 7.

[0031] The discharge pipeline includes a discharge main pipe 9, which is connected to the connecting pipe 6. In the direction away from the connecting pipe 6, the discharge main pipe 9 is sequentially connected to a vent pipe 10, a discharge pipe 11 and a material reverse arch pipe 12. Valves are provided on the vent pipe 10, the discharge pipe 11 and the material reverse arch pipe 12.

[0032] The bottom of the precision filter 1 is connected to a bubbling line 4, which transports 0.6 MPaG nitrogen to the bottom of the precision filter 1.

[0033] When filtering silicon powder, the material enters the precision filter 1 from the feed pipeline 2, and the amorphous silicon powder in the material is filtered on the filter element 102. After filtering, the material passes through the partition 101 from the inside of the filter element 102 and enters the corresponding discharge cavity. The materials in the four discharge cavities are then transported into the connecting pipe 6 through four conveying pipes 5 and collected, and finally enter the discharge pipeline from the connecting pipe 6.

[0034] During backwashing, the valve of the feed line 2 is closed, the valves of the vent pipe 10 and the discharge pipe 11 in the discharge pipeline are closed, the valve of the material back-arch pipe 12 is opened, and the bubbling line 4 inputs nitrogen into the precision filter 1 for bubbling. The nitrogen can disturb the silicon powder on the surface of the filter element 102, causing it to fall off or loosen. During the bubbling process, the internal pressure of the precision filter 1 increases, and the nitrogen and part of the material are discharged from the material back-arch pipe 12. After the bubbling is completed, the valve of the material back-arch pipe 12 is closed, and then the valve of the backwashing line 7 is opened. The backwashing liquid passes through the connecting pipe 6 and then enters the four conveying pipes 5. During this process, the air inlet pipe 8 inputs nitrogen into the backwashing line 7, and the backwashing liquid enters the filter element 102 downward from the four discharge chambers, and the silicon powder on the surface of the filter element 102 is washed away by reverse flow. The silicon powder is then discharged from the sewage line 3, thereby realizing backwashing of the filter element 102.

[0035] The utility model is provided with a bubbling pipeline 4, and nitrogen is bubbled into the precision filter 1 before backwashing, so that the silicon powder on the surface of the filter element 102 falls off or loosens, and avoids the silicon powder from being tightly adhered to the surface of the filter element 102, which makes it difficult to be washed away by the backwashing liquid. The baffle 103 is used to divide the four discharge chambers to realize the partitioning of the interior of the precision filter 1. When backwashing is performed, each discharge chamber, that is, each partition, is separately input with backwashing liquid by the delivery pipe 5, so that the backwashing effect of the filter element 102 in each partition is improved and the flushing is thorough, the silicon powder on the surface of the filter element 102 is completely washed away, and the operation cycle of the precision filter 1 is improved.

[0036] The above embodiments are only preferred embodiments of the present invention and are not limitations on the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A silicon powder filtration system, characterized in that: include: precision filters; The feed pipeline, the discharge pipeline and the sewage pipeline are connected to the side, the top and the bottom of the precision filter respectively; Among them, the discharge pipeline is connected to a backwash pipeline, and the bottom of the precision filter is connected to a bubbling pipeline.

2. The silicon powder filtration system according to claim 1, characterized in that: The top of the precision filter is connected to a delivery pipe, the delivery pipe is connected to a connecting pipe, and valves are provided on the discharge pipeline and the backwash pipeline and are respectively connected to the connecting pipe.

3. The silicon powder filtration system according to claim 2, characterized in that: The backwash pipeline is connected to an air inlet pipe, and a valve is provided on the air inlet pipe.

4. The silicon powder filtration system according to claim 2, characterized in that: The discharge pipeline includes a discharge main pipe, which is connected to a connecting pipe. In the direction away from the connecting pipe, the discharge main pipe is sequentially connected to a vent pipe and a discharge pipe, and both the vent pipe and the discharge pipe are provided with valves.

5. The silicon powder filtration system according to claim 4, characterized in that: The discharge main pipe on the side of the discharge pipe away from the vent pipe is connected with a material reverse arch pipe, and the material reverse arch pipe is provided with a valve.

6. The silicon powder filtration system according to claim 2, characterized in that: A plurality of filter elements are provided in the middle of the precision filter, a partition is provided on the upper portion of the precision filter, and a plurality of filter elements are provided at the bottom of the partition.

7. The silicon powder filtration system according to claim 6, characterized in that: Two crossed and connected baffles are provided in the precision filter above the partition, and the two baffles cross to divide the space above the partition into four discharge cavities. Four conveying pipes are provided on the precision filter, which are respectively connected to the four discharge cavities, and the four conveying pipes are connected to the connecting pipe.

8. The silicon powder filtration system according to claim 7, characterized in that: The internal cross-section of the precision filter is circular, the two baffles are vertically arranged, and the two baffles are arranged along the radial direction of the cross-section of the precision filter. The two baffles evenly divide the upper space of the partition into four discharge cavities.

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