Silicon material cleaning apparatus and method of use

Abstract

The present application relates to the technical field of polysilicon production, and particularly relates to a silicon material cleaning device and a use method, which comprises a cylinder, a CDI module and a circulation pipe, the CDI module is arranged in a containing space of the cylinder, so that the containing space is formed with a concentrated brine chamber at both ends and a dilute brine chamber in the middle, the silicon material is arranged in a cleaning area, the circulation pipe is arranged at both sides of the cylinder, one end of the circulation pipe is communicated with the cleaning area, and the other end of the circulation pipe is communicated with a cation-anion resin mixing area, which is used for quickly introducing the cleaning water in the cleaning area into the cation-anion resin mixing area, the CDI module and the circulation pipe are combined, so that the ions adhered to the silicon material can quickly pass through the anion exchange membrane and the cation exchange membrane and are enriched in the concentrated brine chamber, the water in the cleaning area is always kept in a low ion concentration state, the circulation pipe drives the cleaning water in the cleaning area and the cation-anion resin mixing area to circulate, the continuous water supply is not needed, the amount of ultrapure water is reduced, the production cost of the silicon material is reduced, the output of the acidic wastewater is reduced, and the wastewater treatment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of polysilicon production technology, specifically to a silicon material cleaning device and its usage method. Background Technology

[0002] Polycrystalline silicon is one of the main raw materials for semiconductors, and high-purity polycrystalline silicon has a silvery-gray metallic luster. However, during the production process, raw materials and equipment can contaminate it, especially with the introduction of oxygen, which can form silicon oxide, causing it to lose its metallic luster. Silicon oxide can cause "silicon jump" during single crystal pulling and "melting breakage zones" during zone melting. Therefore, acid etching is required in the post-processing of polycrystalline silicon. However, after acid etching, acid radicals adhere to the silicon material, necessitating rinsing with ultrapure water.

[0003] However, the ultrapure water rinsing method mentioned above consumes a large amount of water, which leads to very high and persistently high polysilicon production costs, and also generates acidic wastewater that needs to be treated before it can be discharged.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a silicon material cleaning device and a method of use, thereby effectively solving the problems pointed out in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A silicon material cleaning apparatus, comprising:

[0008] The cylindrical body has a receiving space inside;

[0009] The CDI module is located within the containment space and includes vertically spaced anion exchange membranes, cation exchange membranes, and positive and negative electrodes at both ends. When the positive and negative electrodes are energized, the containment space forms a concentrated brine chamber at both ends and a dilute brine chamber in the middle. The bottom of the dilute brine chamber is provided with an anion and cation resin mixing area, and the top is a cleaning area, in which silicon material is placed.

[0010] The bottom of the cylinder is equipped with an air inlet pipe for introducing high-purity inert gas. When the cylinder is filled with gas, its density is low and its volume expands, forcing the cleaning water in the cleaning zone to rise.

[0011] A circulation pipe is provided on both sides of the outer surface of the cylinder. One end of the circulation pipe is connected to the upper layer of the cleaning zone, and the other end is connected to the lower layer of the anion and cation resin mixing zone. Under the action of the high-purity inert gas, the cleaning water of the cleaning zone is quickly introduced into the anion and cation resin mixing zone through the circulation pipe, forming a cleaning water circulation between the cleaning zone and the anion and cation resin mixing zone, thereby accelerating the frequency of ultrapure water renewal in the cleaning zone.

[0012] Furthermore, a partition is provided at the bottom of the cylinder near the CDI module, and a porous area is provided in the middle of the partition, which corresponds to the anion and cation resin mixing area.

[0013] Furthermore, a cleaning basket is detachably installed in the cleaning area, and the bottom and sides of the cleaning basket are provided with several through holes.

[0014] Furthermore, the top end of the air intake pipe is flush with the bottom of the cylinder.

[0015] Furthermore, the top end of the air intake pipe is disposed through the anion and cation resin mixing zone.

[0016] Furthermore, the top end of the air intake pipe is provided with a nozzle, and the upper half of the nozzle is provided with several air outlet holes.

[0017] Furthermore, the high-purity inert gas is either nitrogen or argon.

[0018] Furthermore, a concentrated brine discharge port is provided on the side of the cylinder near the concentrated brine chamber.

[0019] Furthermore, a cap is provided on the top of the cylinder, and the cap is detachably connected to the cylinder.

[0020] The present invention also includes a method of using the silicon cleaning apparatus as described above, characterized in that it includes:

[0021] Place the silicon material in the cleaning area;

[0022] High-purity inert gas is introduced through the intake pipe;

[0023] The positive and negative terminals are energized.

[0024] The water in the cleaning area is tested regularly to determine whether it meets the standards for ultrapure water. If it does, the cleaning of the silicon material is complete; otherwise, the cleaning process continues.

[0025] Regular analysis of water samples in the concentrated saline chamber allows for timely removal of the concentrated saline solution.

[0026] The technical solution of this invention can achieve the following technical effects:

[0027] The combination of the CDI module and the circulating tube allows ions adhering to the silicon material to pass quickly through the anion exchange membrane and cation exchange membrane, and be enriched in the concentrated brine chamber, thus maintaining the water in the cleaning zone at a low ion concentration. The circulating tube drives the circulation of cleaning water in the cleaning zone and the anion and cation resin mixing zone, eliminating the need for continuous water supply, reducing the amount of ultrapure water used, lowering the cost of polysilicon production, and simultaneously reducing the production of acidic wastewater, thus lowering wastewater treatment costs.

[0028] During the silicon cleaning process, the silicon material is placed above the anion and cation resin mixing zone. The silicon material comes into contact with the cleaning water, and the acid, alkali, and salt ions adhering to its surface dissolve in the high-purity water. Another function of introducing high-purity inert gas is to promote water flow disturbance, causing the silicon material to change from a static to a dynamic state, so that the water and silicon material can fully contact each other. Moreover, the bubbles gradually grow larger as they rise, and they will burst when they hit the silicon material, pushing the silicon material outward and forming a vacuum area. The upper layer of silicon material naturally falls down to fill the voids, promoting the "flow" of silicon material and ensuring full contact between the water and silicon material, which helps to improve cleaning efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a front view of the silicon cleaning device;

[0031] Figure 2 A top view of the silicon cleaning device without the end caps;

[0032] Figure 3 A schematic diagram showing the locations of the CDI module, cleaning basket, and partition;

[0033] Figure 4 This is a schematic diagram of the partition structure;

[0034] Figure 5 This is a schematic diagram of the silicon cleaning device in Example 1;

[0035] Figure 6 This is a schematic diagram of the silicon material cleaning device in Example 2.

[0036] Reference numerals: 1. Cylinder; 11. Containing space; 111. Cleaning zone; 12. Air inlet pipe; 121. Nozzle; 13. Concentrated brine outlet; 14. Control valve; 15. End cap; 16. Exhaust pipe; 2. CDI module; 21. Anion exchange membrane; 22. Cation exchange membrane; 23. Positive electrode; 24. Negative electrode; 25. Concentrated brine chamber; 26. Dilute brine chamber; 27. Anion and cation resin mixing zone; 3. Circulation pipe; 4. Baffle plate; 41. Porous zone; 5. Cleaning basket. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] Example 1:

[0040] like Figures 1 to 5 As shown: A silicon material cleaning device, comprising:

[0041] Cylinder 1, with an internal receiving space 11;

[0042] CDI module 2 is located in the containing space 11 and includes anion exchange membrane 21 and cation exchange membrane 22 arranged vertically at intervals, and positive electrode 23 and negative electrode 24 at both ends. After the positive electrode 23 and negative electrode 24 are energized, the containing space 11 forms a concentrated brine chamber 25 at both ends and a dilute brine chamber 26 in the middle. The bottom of the dilute brine chamber 26 is provided with anion and cation resin mixing area 27, and the top is a cleaning area 111. Silicon material is placed in the cleaning area 111.

[0043] The bottom of the cylinder 1 is equipped with an air inlet pipe 12 for introducing high-purity inert gas. When the cylinder is filled with gas, the density is low and the volume expands, which forces the cleaning water in the cleaning zone 111 to rise. At the same time, the water and gas continuously disturb the silicon material, making the silicon material "flow" continuously, which can fully clean the silicon material.

[0044] The circulation pipe 3 is located on both sides of the outer surface of the cylinder 1. One end of the circulation pipe 3 is connected to the upper layer of the cleaning zone 111, and the other end is connected to the lower layer of the anion and cation resin mixing zone 27. Under the action of high-purity inert gas, the cleaning water of the cleaning zone 111 is quickly introduced into the anion and cation resin mixing zone 27 through the circulation pipe 3, forming a circulation flow of cleaning water between the cleaning zone 111 and the anion and cation resin mixing zone 27, thereby accelerating the frequency of ultrapure water renewal in the cleaning zone.

[0045] By configuring the cylinder 1, CDI module 2, and circulating pipe 3, during the cleaning of silicon material, the silicon material is placed in the cleaning zone 111, and high-purity inert gas is introduced through the air inlet pipe 12. When water is filled with gas, its density is low and its volume expands, forcing the cleaning water in the cleaning zone 111 to rise. The cleaning water in the circulating pipe 3 flows downward in a regular circulation, ensuring good mixing between the cleaning water in the cleaning zone 111 and the cleaning water in the anion and cation resin mixing zone 27. This facilitates the rapid diffusion of ions to the anion and cation resin mixing zone 27. Simultaneously, the positive electrode 23 and the negative electrode 24 are connected to a power source, and the silicon material adheres to... Under the influence of the current, the attached ions are enriched in the concentrated brine chambers 25 on both sides. The combination of CDI module 2 and circulating pipe 3 allows the ions adhering to the silicon material to pass quickly through the anion exchange membrane 21 and cation exchange membrane 22 and be enriched in the concentrated brine chamber 25, keeping the water in the cleaning zone 111 at a low ion concentration. The circulating pipe 3 drives the circulation of cleaning water in the cleaning zone 111 and the anion and cation resin mixing zone 27, eliminating the need for continuous water supply, reducing the amount of ultrapure water used, reducing the production cost of polysilicon, and reducing the output of acidic wastewater, thus reducing wastewater treatment costs.

[0046] During the silicon cleaning process, the silicon material is placed above the anion and cation resin mixing zone 27. The silicon material comes into contact with the cleaning water, and the acid, alkali, and salt ions adhering to the surface dissolve in the high-purity water. Another function of introducing high-purity inert gas is to promote water flow disturbance, so that the silicon material accumulation state changes from static to dynamic, allowing the water and silicon material to fully contact each other. Moreover, the bubbles gradually grow larger as they rise, and they will burst when they hit the silicon material, pushing the silicon material outward. At the same time, a vacuum area is formed, and the upper layer of silicon material naturally falls to fill the void, promoting the "flow" of silicon material and allowing the water and silicon material to fully contact each other, which helps to improve the cleaning efficiency.

[0047] Since the area above the anion and cation resin mixing zone 27 is left empty as the cleaning zone 111, the ion mass transfer process between the upper and lower water layers will be weakened. When the water is filled with gas, the density is low and the volume expands. Therefore, the circulation pipe 3 is added to quickly introduce the upper cleaning water into the lower anion and cation resin mixing zone 27, ensuring the mass transfer rate, which helps to improve the ion removal rate and increase the cleaning efficiency.

[0048] In the later stages of cleaning, the resistivity of the water in cleaning zone 111 is measured. If it reaches the standard of ultrapure water, it indicates that the cleaning of the silicon material has been completed.

[0049] As a preferred embodiment, a partition 4 is provided inside the cylinder 1 near the bottom of the CDI module 2. A porous region 41 is provided in the middle of the partition 4, corresponding to the anion and cation resin mixing region 27. Specifically, this facilitates the flow of high-purity inert gas through and into the anion and cation resin mixing region 27 of the CDI module 2, thereby promoting internal and external circulation, promoting the diffusion of cleaning water between the upper and lower layers, ensuring that all parts of the cleaning device can fully participate in the cleaning process, thus improving the efficiency of silicon cleaning. In addition, the partition 4 also serves to support the CDI module 2, preventing deformation or warping of the CDI module 2 during use, and helping to maintain the overall structural stability of the cleaning device.

[0050] In this embodiment, a cleaning basket 5 is detachably installed in the cleaning zone 111, and the cleaning basket 5 has several through holes on its bottom and sides. Specifically, during cleaning, the silicon material is placed in the cleaning basket 5, and ultrapure water flows in and out from the bottom and sides of the cleaning basket 5, effectively removing ions from the surface of the silicon material and improving the cleaning effect.

[0051] The top end of the air intake pipe 12 is flush with the bottom of the cylinder 1. For example... Figure 5 As shown, high-purity inert gas enters the bottom of cylinder 1 through inlet pipe 12. The gas first accumulates between the bottom of cylinder 1 and partition 4. After reaching a certain concentration, it passes through the anion and cation resin mixing zone 27 along the porous area 41 in the middle of partition 4, which enhances the deep desalination effect and achieves continuous removal of ions from the aqueous solution to produce pure water or high-purity water. At the same time, after the gas and liquid are mixed, due to the existence of the flow rate, the density of the cleaning water in the anion and cation resin mixing zone 27 at the bottom of cylinder 1 is low, which forces the liquid level of the cleaning water in cleaning zone 111 to rise. The cleaning water flows back to the anion and cation resin mixing zone 27 from the circulation pipes 3 on both sides, so that the cleaning water in cleaning zone 111 and the anion and cation resin mixing zone 27 circulates, which continuously and thoroughly cleans the silicon material. While the circulating cleaning water continuously rinses the silicon material, the circulating cleaning water continuously removes ions from the cleaning water to produce pure water or high-purity water, reducing the amount of high-purity water used and reducing costs.

[0052] As a preferred embodiment of the above, the high-purity inert gas is either nitrogen or argon. On the one hand, during the cleaning process, the gas will not chemically react with the silicon material or other cleaning media, avoiding the introduction of external impurities or affecting the purity of the silicon material. On the other hand, both nitrogen and argon can provide a protective atmosphere, preventing the silicon material from being contaminated by the air during the cleaning process, which is crucial for maintaining the high purity of the silicon material and preventing oxidation. Furthermore, using nitrogen or argon as the cleaning medium allows for precise control of the cleaning process; adjusting the gas flow rate and other parameters can meet different cleaning needs, making the device suitable for various silicon materials and cleaning scenarios.

[0053] In this embodiment, a concentrated brine discharge port 13 is provided on the side of the cylinder 1 near the concentrated brine chamber 25. Specifically, both the concentrated brine discharge port 13 and the air inlet pipe 12 are equipped with control valves 14. The control valve 14 of the concentrated brine discharge port 13 controls the opening and closing of the concentrated brine discharge port 13, which helps to effectively treat waste liquid and ensure the smooth progress of the cleaning process. The control valve 14 of the air inlet pipe 12 can be used to adjust the flow rate of gas in the air inlet pipe 12. By adjusting the opening degree of the control valve 14, the inflow rate of gas can be controlled to meet the needs of the system or equipment.

[0054] The cylinder 1 has a cap 15 on top, which is detachably connected to the cylinder 1. Specifically, the detachable connection can be a threaded connection, a snap-fit ​​connection, etc. In use, the detachable connection design of the cap 15 allows the operator to quickly open the cap 15 for easy removal or placement of silicon material; the detachable connection of the cap 15 also makes the interior of the cleaning device easily accessible, facilitating maintenance and cleaning.

[0055] As a preferred embodiment of the above, an exhaust pipe 16 is provided above the end cap 15. Specifically, by timely venting the gas inside the cylinder 1, pressure changes in the system can be prevented, ensuring the stable operation of the cleaning process. The presence of the exhaust pipe 16 helps maintain the stability of the cleaning system. The design of the exhaust pipe 16 also helps improve operational safety. By venting, the pressure accumulated in the system can be reduced, the fluctuation of the cleaning water can be slowed down, and the risk of accidental overflow can be reduced, thereby ensuring the safety of the operators.

[0056] Example 2:

[0057] like Figure 6 As shown, unlike Example 1, the top end of the air inlet pipe 12 passes through the anion and cation resin mixing zone 27. Specifically, in this design, a certain gap is maintained between the bottom of the cleaning basket 5 and the anion and cation resin mixing zone 27. The top end of the air inlet pipe 12 passes through the anion and cation resin mixing zone 27, and the air outlet of the air inlet pipe 12 is located at the bottom of the cleaning basket 5. This ensures that the jet kinetic energy of the gas entering the cleaning water in the cleaning zone 111 is reduced, and the density of the cleaning water is decreased. This increases the circulation power between the cleaning zone 111 and the anion and cation resin mixing zone 27, thereby increasing the cleaning efficiency of the silicon material.

[0058] As a preferred embodiment, the top end of the air inlet pipe 12 is provided with a nozzle 121, and the upper half of the nozzle 121 is provided with several air outlets. Specifically, the nozzle 121 can be spherical as shown in the figure, or it can be a nozzle 121 of other shapes. It has a certain spray speed to drive the cleaning water flow and raise the liquid level. The upper half of the spherical shape is provided with several air outlets, which can make the inert gas blow upward or obliquely upward evenly, which helps to form a uniform gas flow field at the bottom of the cylinder 1, thereby achieving uniform cleaning of the silicon material. The uniform gas spray can ensure that the cleaning water is uniformly agitated and impacted, improving the cleaning effect.

[0059] The present invention also includes a method of using the silicon cleaning apparatus as described above, characterized in that it includes:

[0060] Place the silicon material in cleaning area 111;

[0061] High-purity inert gas is introduced through the intake pipe 12;

[0062] Power on positive terminal 23 and negative terminal 24;

[0063] The water in cleaning zone 111 is tested regularly to determine whether it meets the standards for ultrapure water. If it does, the silicon cleaning is complete; otherwise, the cleaning process continues. Specifically, the water in cleaning zone 111 can be tested for resistivity, total dissolved solids (TDS), dissolved oxygen, etc., at least one of the above methods can be used to determine whether it meets the standards for ultrapure water.

[0064] Regular analysis of water samples in the concentrated saline chamber 25 allows for timely removal of the concentrated saline solution.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A silicon material cleaning device, characterized in that, include: The cylindrical body has a receiving space inside; The CDI module is located within the containment space and includes vertically spaced anion exchange membranes, cation exchange membranes, and positive and negative electrodes at both ends. When the positive and negative electrodes are energized, the containment space forms a concentrated brine chamber at both ends and a dilute brine chamber in the middle. The bottom of the dilute brine chamber is provided with an anion and cation resin mixing area, and the top is a cleaning area, in which silicon material is placed. The cylinder body is provided with a partition near the bottom of the CDI module, and the partition has a porous area in the middle, which corresponds to the anion and cation resin mixing area; The bottom of the cylinder is equipped with an air inlet pipe for introducing high-purity inert gas. When filled with gas, the density is low and the volume expands, forcing the cleaning water in the cleaning zone to rise. After the high-purity inert gas is introduced, rising bubbles are generated, and the bubbles gradually grow larger during the rising process. When they come into contact with the silicon material, they will burst, pushing the silicon material outward and forming a vacuum area. The upper layer of silicon material falls naturally to fill the void, promoting the flow of silicon material and allowing the water to fully contact the silicon material. A circulation pipe is provided on both sides of the outer surface of the cylinder. One end of the circulation pipe is connected to the upper layer of the cleaning zone, and the other end is connected to the lower layer of the anion and cation resin mixing zone. Under the action of the high-purity inert gas, the cleaning water in the circulation pipe flows downward in a regular circulation flow. This is used to quickly introduce the cleaning water of the cleaning zone into the anion and cation resin mixing zone through the circulation pipe, forming a cleaning water circulation flow between the cleaning zone and the anion and cation resin mixing zone, thereby accelerating the frequency of ultrapure water renewal in the cleaning zone.

2. The silicon material cleaning apparatus according to claim 1, characterized in that, A detachable cleaning basket is provided in the cleaning area, and the bottom and sides of the cleaning basket are provided with several through holes.

3. The silicon material cleaning apparatus according to claim 1, characterized in that, The top of the air intake pipe is flush with the bottom of the cylinder.

4. The silicon material cleaning apparatus according to claim 1, characterized in that, The top end of the air intake pipe is positioned to pass through the anion and cation resin mixing zone.

5. The silicon material cleaning apparatus according to claim 4, characterized in that, The top of the air intake pipe is provided with a nozzle, and the upper half of the nozzle is provided with several air outlet holes.

6. The silicon material cleaning apparatus according to claim 1, characterized in that, The high-purity inert gas is either nitrogen or argon.

7. The silicon material cleaning apparatus according to claim 1, characterized in that, A concentrated brine discharge port is provided on the side of the cylinder near the concentrated brine chamber.

8. The silicon material cleaning apparatus according to claim 1, characterized in that, The cylinder is provided with a cap on top, and the cap is detachably connected to the cylinder.

9. A method of using the silicon material cleaning apparatus as described in claim 1, characterized in that, include: Place the silicon material in the cleaning area; High-purity inert gas is introduced through the intake pipe; The positive and negative terminals are energized. The water in the cleaning area is tested regularly to determine whether it meets the standards for ultrapure water. If it does, the cleaning of the silicon material is complete; otherwise, the cleaning process continues. Regular analysis of water samples in the concentrated saline chamber allows for timely removal of the concentrated saline solution.

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