Purification device for electronic grade polycrystalline silicon isostatic pressing graphite

Abstract

The utility model relates to the technical field of isostatic pressing graphite piece purification, in particular to a purification device for electronic grade polycrystalline silicon isostatic pressing graphite, which comprises a box body, a rotating ball and a gas distributor, a gas inlet is formed in one end, close to the bottom, of the side of the box; a temperature measuring opening is formed in one side of the gas inlet and in the middle of the box body; a vacuum hole is formed in one end, close to the top, of the side surface of the box body; wherein the rotating ball is arranged in the middle upper part of the box body; and the gas distributor is positioned in the middle lower part of the box body. According to the device disclosed by the utility model, metal oxides in graphite are removed by adopting a hydrogen chloride roasting method, full contact of a gas phase and a solid phase is ensured by virtue of a porous structure and a rotatable characteristic of the spheroids, the metal oxides in the graphite can be removed, and the purity of the graphite required by electronic-grade polycrystalline silicon is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of isostatic graphite piece purification, in particular to a purification device for electronic grade polysilicon isostatic graphite. Background Art

[0002] Currently, the most commonly used method for producing electronic-grade polysilicon is the modified Siemens method, which uses hydrogen chloride and industrial silicon powder to synthesize trichlorosilane at a certain temperature, and then separates and purifies the trichlorosilane. The purified trichlorosilane undergoes a chemical vapor deposition reaction in a reduction furnace to generate polysilicon that is deposited on the silicon core in the reduction furnace; the silicon core in the reduction furnace is generally placed on a graphite chuck.

[0003] The graphite chucks for electronic-grade polysilicon are generally made of isostatically pressed graphite parts. They use high-purity graphite materials and undergo precision machining and special treatment. However, the graphite parts will be contaminated during the processing and manufacturing process. During the polysilicon production process, the graphite parts are in direct contact with the polysilicon products. The impurities in the graphite parts enter the polysilicon products, thereby affecting the purity of the polysilicon products. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a purification device for electronic grade polysilicon and other static graphite, which effectively solves the problems in the background technology.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a purification device for electronic grade polysilicon isostatic graphite, including a box body, a rotating ball and a gas distributor, the box body is cylindrical; a gas inlet is provided at one end of the side of the box body near the bottom; a temperature measuring port is provided on one side of the gas inlet and in the middle of the box body; a vacuum hole is provided at one end of the side of the box body near the top, and a gas discharge port is provided at the top of the box body; wherein the rotating ball is arranged inside the middle and upper part of the box body; and the gas distributor is located inside the middle and lower part of the box body.

[0006] Furthermore, a plurality of through holes are evenly distributed on the upper surface of the gas distributor.

[0007] Furthermore, a rotation axis is provided at the center of the rotating ball and extends to the outside of the box.

[0008] Furthermore, the rotating ball is composed of an upper hemisphere and a lower hemisphere adsorbed together by a magnetic attraction device, and pores communicating with the interior are evenly distributed on the surface of the rotating ball.

[0009] Furthermore, a circle of magnets is respectively provided on the contact surface of the upper hemisphere and the contact surface of the lower hemisphere.

[0010] Furthermore, both the upper hemisphere and the lower hemisphere are provided with air windows.

[0011] Furthermore, a plurality of bases are arranged in parallel inside the lower hemisphere.

[0012] Furthermore, the base is an arched hollow structure, and a plurality of small air holes are arranged on its surface.

[0013] Furthermore, a support rod is arranged directly above the base.

[0014] The utility model adopts a hydrogen chloride roasting method to remove metal oxides in graphite, ensures sufficient contact between gas and solid phases through the porous structure and rotatable characteristics of the spherical body, can remove metal oxides in graphite, and ensure the purity of graphite required for electronic grade polysilicon. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of the structure of a purification device for electronic-grade polysilicon isostatic graphite in an embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of a rotating ball in an embodiment of the utility model;

[0018] Figure 3 It is a cross-sectional view of a rotating ball in an embodiment of the utility model.

[0019] Figure numerals: 1. box body; 2. rotating ball; 21. rotating axis; 22. upper hemisphere; 23. lower hemisphere; 24. air hole; 25. air window; 26. base; 261. small air hole; 27. support rod; 3. gas distributor; 31. through hole; 4. gas inlet hole; 5. temperature measuring port; 6. vacuum hole; 7. gas exhaust port; 8. graphite part. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0023] like Figures 1 to 3 The purification device for electronic-grade polysilicon isostatic graphite shown includes a housing 1, a rotating ball 2 and a gas distributor 3. The housing 1 is cylindrical; a gas inlet 4 is provided on the side of the housing 1 near the bottom end; a temperature measuring port 5 is provided on one side of the gas inlet 4 and in the middle of the housing 1; a vacuum hole 6 is provided on the side of the housing 1 near the top end, and a gas exhaust port 7 is provided on the top of the housing 1; wherein the rotating ball 2 is arranged inside the middle and upper part of the housing 1; and the gas distributor 3 is located inside the middle and lower part of the housing 1.

[0024] The implementation principle of the utility model is that after high-temperature heating, impurities in graphite can be decomposed into simple oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, etc. under the action of a reducing agent. These oxides have high melting and boiling points; while their chlorides or metal complexes formed with other trivalent metal chlorides have low melting and boiling points. The oxides in the graphite are converted into chlorides through a chlorination roasting method, and the gasification and escape of the chlorides improves the purity of the graphite.

[0025] The specific implementation process of the utility model is that hydrogen chloride enters the device from the gas inlet 4, and the gas escapes into the purification device through the gas distributor 3. The upper part of the device is equipped with a rotating ball 2, and the rotating ball 2 is a mesh structure. The entering hydrogen chloride contacts the graphite piece 8 placed in the rotating ball 2 through the mesh structure, so that the hydrogen chloride reacts with the oxide in the graphite, converts the oxide into chloride, and removes the impurity components in the graphite piece through high-temperature escape.

[0026] The graphite support is placed in the rotating ball 2 and snap-connected with the rotating ball 2. The rotation speed of the rotating shaft 21 is adjusted through the temperature measuring port 5. The temperature is heated to above 800 degrees and kept warm for 60 minutes. At the same time, hydrogen chloride is introduced at a flow rate of 150 L / h. The hydrogen chloride fully contacts the graphite piece 8 through the pores 24 of the rotating ball 2. After the reaction lasts for ten minutes, the rotating ball 2 is rotated through the rotating shaft 21 to ensure that the graphite is fully contacted with the hydrogen chloride and remove the surface impurities of the graphite.

[0027] In order to distribute the gas more evenly inside the box 1, a plurality of through holes 31 are evenly distributed on the upper surface of the gas distributor 3. A rotating shaft 21 is arranged at the center of the rotating ball 2 and extends to the outside of the box 1. By rotating, the graphite piece 8 is ensured to be in full contact with the hydrogen chloride gas.

[0028] In a preferred embodiment of the utility model, the rotating ball 2 is composed of an upper hemisphere 22 and a lower hemisphere 23 adsorbed together by a magnetic attraction device, so that the connection between the upper and lower hemispheres is more stable and easy to disassemble. The surface of the rotating ball 2 is evenly distributed with air holes 24 that are connected to the inside, ensuring that the gas can enter the interior of the rotating ball 2 and contact the graphite member 8. The contact surfaces of the upper hemisphere 22 and the lower hemisphere 23 are each provided with a circle of magnets, which is convenient for adsorbing the upper hemisphere 22 and the lower hemisphere 23 together. The upper hemisphere 22 and the lower hemisphere 23 are both provided with air windows to ensure that the gas inside and outside are connected. A plurality of bases 26 are arranged in parallel inside the lower hemisphere 23. The base 26 is an arched hollow structure, and a plurality of small air holes 261 are arranged on its surface, so that the gas can enter the upper part through the small air holes 261 to contact and react with the graphite member 8. A support rod 27 is arranged directly above the base 26 to support and fix the graphite member 8 to ensure that the graphite member 8 does not shake when the rotating ball 2 rotates, thereby affecting the reaction process.

[0029] Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the description are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A purification device for electronic grade polysilicon isostatic graphite, comprising a housing (1), a rotating ball (2) and a gas distributor (3), characterized in that: The box body (1) is cylindrical; a gas inlet (4) is provided on the side of the box body (1) near the bottom; a temperature measuring port (5) is provided on one side of the gas inlet (4) and in the middle of the box body (1); a vacuum hole (6) is provided on the side of the box body (1) near the top, and a gas exhaust port (7) is provided on the top of the box body (1); wherein the rotating ball (2) is arranged inside the middle and upper part of the box body (1); and the gas distributor (3) is located inside the middle and lower part of the box body (1).

2. The purification device for electronic grade polysilicon isostatic graphite according to claim 1, characterized in that: A plurality of through holes (31) are evenly distributed on the upper surface of the gas distributor (3).

3. The purification device for electronic grade polysilicon isostatic graphite according to claim 1, characterized in that: A rotating shaft (21) is arranged at the center of the rotating ball (2) and extends to the outside of the box body (1).

4. The purification device for electronic grade polysilicon isostatic graphite according to claim 1, characterized in that: The rotating ball (2) is composed of an upper hemisphere (22) and a lower hemisphere (23) adsorbed together by a magnetic attraction device, and air holes (24) communicating with the interior are evenly distributed on the surface of the rotating ball (2).

5. The purification device for electronic grade polysilicon isostatic graphite according to claim 4, characterized in that: A circle of magnets is respectively arranged on the contact surfaces of the upper hemisphere (22) and the lower hemisphere (23).

6. The purification device for electronic grade polysilicon isostatic graphite according to claim 4, characterized in that: The upper hemisphere (22) and the lower hemisphere (23) are both provided with air windows.

7. The purification device for electronic grade polysilicon isostatic graphite according to claim 4, characterized in that: A plurality of bases (26) are arranged in parallel inside the lower hemisphere (23).

8. The purification device for electronic grade polysilicon isostatic graphite according to claim 7, characterized in that: The base (26) is an arched hollow structure, and a plurality of small air holes (261) are arranged on its surface.

9. The purification device for electronic grade polysilicon isostatic graphite according to claim 8, characterized in that: A support rod (27) is arranged directly above the base (26).

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