An adsorption tower for polysilicon production

Abstract

This utility model relates to the field of polycrystalline silicon production technology, and in particular to an adsorption tower for polycrystalline silicon production. The tower includes a main body with several baffles dividing its interior into chambers for holding corresponding adsorbents. Each chamber is connected to an inlet pipe, an outlet pipe, and a first nitrogen purging pipe. Valves are installed on the inlet pipe, outlet pipe, and the first nitrogen purging pipe. Several outlet pipes correspond one-to-one with each chamber. The baffles are inclined downwards towards the outlet pipe, with their lowest point extending into the opening area of ​​the outlet pipe. The first nitrogen purging pipe is connected to a nitrogen source and is used to blow nitrogen into the surface of the baffles in the corresponding chambers to complete the unloading and purging of the adsorbent. This adsorption tower effectively solves the problems of incomplete unloading and inconvenient adsorbent loading.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline silicon production technology, and in particular to an adsorption tower for polycrystalline silicon production. Background Technology

[0002] The main production processes for polycrystalline silicon include chemical vapor deposition (CVD) and the Siemens process. In these processes, adsorption towers are typically used for gas purification to remove impurities and improve product purity. Adsorption towers remove trace amounts of moisture, oxygen, and other impurities from the raw material gas through physical or chemical adsorption, which is crucial for ensuring the high purity of the final product.

[0003] In existing technologies, because a single adsorption tower contains multiple adsorbents, during adsorption loading, a crane is used to lift the bulk bags of adsorbent to the top of the tower. Then, the bottom of the bags is opened, and the adsorbent is filled layer by layer from bottom to top, starting from the top of the tower. The adsorbent is loaded in bulk. When replacement is needed, operators must enter the tower to retrieve it. During this loading process, it is impossible to determine if there is any flow deviation, and the operators are working at a high position at the top of the tower, posing a significant risk. During replacement, the limited space leads to extremely high safety risks.

[0004] In the prior art, a Chinese utility model patent document with publication number CN220276635U and publication date of January 2, 2024 has been proposed. The technical solution disclosed in the patent document is as follows: an adsorption tower, the adsorption tower comprising: a tower body, wherein five layers of adsorption devices are arranged sequentially from bottom to top in the tower body, and adjacent adsorption devices are separated by a wire mesh.

[0005] Although the above technical solution uses wire mesh to separate the adsorption devices, during filling, the material must still be fed from the top of the adsorption tower, layer by layer, with the added step of installing the wire mesh. Replacement also requires operators to enter the adsorption tower and replace the material layer by layer.

[0006] In the prior art, a Chinese utility model patent document with publication number CN209549097U and publication date of October 29, 2019 has also been proposed. The technical solution disclosed in this patent document is as follows: an adsorption tower structure for a hydrogen production device, including an adsorption tower, a vacuum device and a discharge device, wherein the adsorption tower is filled with adsorbent; wherein, a discharge port communicating with the interior of the adsorption tower is provided on the outer wall of the adsorption tower, and the discharge device is used to communicate with the discharge port so that the adsorbent after desorption is discharged through the discharge port to the discharge device for collection.

[0007] Although the above technical solution includes a discharge device and requires nitrogen purging, this technology is applied to hydrogen production in coal chemical industry, which releases toxic and flammable gases. Therefore, the nitrogen purging is only for safety reasons and is used in conjunction with the vacuum device. In actual use, it is still necessary to feed the adsorbent from the top of the adsorption tower to achieve layer-by-layer filling. Although a discharge device is provided, the horizontal arrangement of the separator creates a dead zone between the separator and the discharge port, leading to incomplete discharge during automatic unloading. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention proposes an adsorption tower for polycrystalline silicon production, which effectively solves the problems of incomplete unloading and inconvenient adsorbent filling.

[0009] This utility model is achieved by adopting the following technical solution:

[0010] An adsorption tower for polycrystalline silicon production includes an adsorption tower body. The adsorption tower body has several baffles that divide its interior into several chambers for placing corresponding adsorbents. Each chamber is connected to a feed pipe, a discharge pipe, and a first nitrogen purging pipe. Valves are provided on the feed pipe, discharge pipe, and the first nitrogen purging pipe. There are several discharge pipes, each corresponding to one of the chambers. The baffles are inclined downwards towards the discharge pipe, and the lowest point of the baffle extends into the opening area of ​​the discharge pipe. The first nitrogen purging pipe is connected to a nitrogen source and is used to blow nitrogen into the surface of the baffle in the corresponding chamber to complete the unloading and purging operation of the adsorbent.

[0011] It also includes an adsorbent feeding tank connected to the feed pipe.

[0012] A second nitrogen purging pipe is also provided between the adsorbent feeding tank and the nitrogen source, and a second valve is provided on the second nitrogen purging pipe.

[0013] The feed pipe is connected to the bottom of the adsorbent feeding tank, and the second nitrogen purging pipe is connected to the top of the adsorbent feeding tank.

[0014] It also includes an access pipe corresponding to each chamber. One end of the access pipe is connected to the adsorption tower body and communicates with the corresponding chamber, and the other end is connected to the feed pipe and the first nitrogen purging pipe, respectively.

[0015] A third valve is also provided on the access pipe.

[0016] The access pipe is connected to the top of the corresponding chamber, and the access pipe at one end near the chamber is inclined downward toward the partition.

[0017] The number of feed pipes and first nitrogen purging pipes is the same as the number of access pipes; the end of the access pipe away from the chamber is provided with two branches, including a first branch and a second branch; the first branch is connected to the corresponding feed pipe, and the second branch is connected to the corresponding first nitrogen purging pipe.

[0018] It also includes a feeding main pipe, and the number of the adsorbent feeding tank, nitrogen source, feed pipe and first nitrogen purging pipe are all one; the access pipe of each chamber is connected to the feeding main pipe, and the other end of the feeding main pipe is connected to the feed pipe and the first nitrogen purging pipe through two branches respectively.

[0019] It also includes a main discharge pipe, and several discharge pipes are connected to the main discharge pipe.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] 1. This utility model, through the cooperative structure of the partition and the discharge pipe, can effectively eliminate dead corners in the unloading process and significantly improve the automatic unloading effect. Furthermore, a first nitrogen purging pipe is provided, utilizing nitrogen to apply positive pressure for unloading. By charging with nitrogen, not only can an auxiliary force be applied to the unloading process, further enhancing unloading efficiency, but also ensuring more thorough unloading.

[0022] In addition, each chamber is connected to a feed pipe, which can realize automatic feeding and unloading operations without removing the partitions, thereby improving operational safety and automation.

[0023] 2. The adsorbent feeding tank allows for centralized storage of the adsorbent, better ensuring its quality and preventing contamination from the external environment. Because the tank can store a certain amount of adsorbent, adsorbent replacement is smoother, ensuring continuous and stable operation of the adsorption tower and reducing downtime.

[0024] 3. The second nitrogen purge pipe allows nitrogen to be injected into the adsorbent feeding tank, creating a positive pressure environment. The adsorbent in the tank can then be pneumatically transported to the corresponding chamber. After the adsorbent transport is complete, nitrogen continues to be introduced through the second nitrogen purge pipe to purge any remaining adsorbent to the corresponding chamber.

[0025] 4. By adjusting the positions of the feed pipe and the second nitrogen purging pipe, the combined effect of gravity and pneumatic force can be fully utilized, resulting in a more thorough purging process.

[0026] 5. By setting up the access pipe, nitrogen and adsorbent can share a single pipe to enter the corresponding chamber, which simplifies the structure of the adsorption tower. The overall design of the adsorption tower is more compact, which is conducive to optimizing the layout in a limited space and reducing maintenance costs.

[0027] 6. A second valve is also installed on the inlet pipe, which can further isolate the passage between the adsorption tower and the inlet pipe during the operation of the adsorption tower, prevent gas or adsorbent leakage, and improve the overall sealing performance of the adsorption tower.

[0028] 7. By setting the position and angle of the inlet pipe, dead zones in the adsorbent or gas flow process can be reduced, and the nitrogen flow can act more concentratedly on the baffle, resulting in a better nitrogen purging effect.

[0029] 8. The number of feed pipes and first nitrogen purging pipes is the same as the number of inlet pipes, which are all several. They are highly independent, and when a problem occurs in a certain pipe or component, it can be quickly located and repaired without affecting the operation of the other pipes.

[0030] 9. By setting up a main feed pipe, all chambers share one adsorbent feed tank, one nitrogen source, one feed pipe, and one nitrogen purging pipe; this integrates the feed and nitrogen purging paths of multiple chambers, greatly simplifies the system structure, reduces the number of failure points, and improves operational stability.

[0031] 10. The installation of a main discharge pipe facilitates centralized collection or subsequent processing. Attached Figure Description

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, wherein:

[0033] Figure 1 This is a schematic diagram of the structure of this utility model;

[0034] Marked in the image:

[0035] 1. Adsorption tower body; 2. Baffle plate; 3. Chamber; 4. Feed pipe; 5. Discharge pipe; 6. First nitrogen purge pipe; 7. Valve; 8. Adsorbent feeding tank; 9. Second nitrogen purge pipe; 10. Inlet pipe; 11. Third valve; 12. Feed main pipe; 13. Discharge main pipe; 14. Second valve. Detailed Implementation

[0036] Example 1

[0037] In a preferred embodiment of this utility model, the present utility model includes an adsorption tower for polycrystalline silicon production, comprising an adsorption tower body 1, wherein both the bottom inlet and the top outlet of the adsorption tower body 1 are equipped with shut-off valves. The adsorption tower body 1 is provided with several partitions 2, dividing the internal space of the adsorption tower body 1 into several chambers 3 for placing corresponding adsorbents. The partitions 2 are conventional technology in the art and will not be described in detail in this embodiment.

[0038] Each chamber 3 is connected to an inlet pipe 4, an outlet pipe 5, and a first nitrogen purging pipe 6. Specifically, each chamber 3 can be equipped with one inlet pipe 4, one outlet pipe 5, and one first nitrogen purging pipe 6. Each inlet pipe 4, outlet pipe 5, and first nitrogen purging pipe 6 is equipped with a valve 7. The partition 2 is inclined downwards towards the outlet pipe 5, and the lowest point of the partition 2 extends into the opening area of ​​the outlet pipe 5. The first nitrogen purging pipe 6 is connected to a nitrogen source and is used to blow nitrogen into the surface of the partition 2 in the corresponding chamber 3 to pressurize the adsorption tower. The adsorbent on the partition 2 enters the outlet pipe 5 and is discharged, completing the unloading of the adsorbent. The blowing of nitrogen can apply an auxiliary force to the unloading process, enhance the unloading efficiency, and also complete the purging operation of the adsorbent, making the unloading more thorough.

[0039] The other end of the feed pipe 4 can be connected to an automatic feeding device, etc. The automatic feeding device is conventional technology in this field and will not be described in detail in this embodiment. By cooperating with an existing automatic feeding device, the feed pipe 4 can achieve automatic feeding of the adsorbent through pneumatic conveying.

[0040] Example 2

[0041] In a preferred embodiment of this utility model, the present utility model includes an adsorption tower for polycrystalline silicon production, comprising an adsorption tower body 1, wherein the bottom inlet and top outlet of the adsorption tower body 1 are equipped with shut-off valves. The adsorption tower body 1 is provided with several partitions 2, dividing the interior of the adsorption tower body 1 into several chambers 3 for placing corresponding adsorbents. Each chamber 3 is connected to a feed pipe 4, a discharge pipe 5, and a first nitrogen purge pipe 6. The number of feed pipes 4, discharge pipes 5, and first nitrogen purge pipes 6 is the same as the number of chambers 3. Each feed pipe 4, discharge pipe 5, and first nitrogen purge pipe 6 is equipped with a valve 7.

[0042] The partition 2 is inclined downward toward the discharge pipe 5, and the lowest point of the partition 2 extends into the opening area of ​​the discharge pipe 5. The first nitrogen purging pipe 6 is connected to a nitrogen source and is used to blow nitrogen into the surface of the partition 2 in the corresponding chamber 3 to complete the unloading and purging operation of the adsorbent.

[0043] The other end of each feed pipe 4 is connected to an adsorbent loading tank 8. Therefore, the number of adsorbent loading tanks 8 is the same as the number of feed pipes 4, each used to store the corresponding adsorbent. Each adsorbent loading tank 8 is also connected to a nitrogen source via a second nitrogen purge pipe 9, which is equipped with a second valve 14. By pressurizing with nitrogen, the adsorbent in the adsorbent loading tank 8 can be directly blown into the corresponding chamber 3 through the feed pipe 4.

[0044] Example 3

[0045] In another preferred embodiment of this utility model, the utility model includes an adsorption tower for polycrystalline silicon production, comprising an adsorption tower body 1, wherein the bottom inlet and top outlet of the adsorption tower body 1 are equipped with shut-off valves. The adsorption tower body 1 is provided with several baffles 2, dividing the interior of the adsorption tower body 1 into several chambers 3 for placing corresponding adsorbents. The adsorption tower also includes several inlet pipes 10 and several outlet pipes 5, each corresponding to one of the chambers 3. The outlet pipes 5 are connected to the adsorption tower body 1 and communicate with the corresponding chamber 3. The baffles 2 are inclined downwards towards the outlet pipes 5, and the lowest point of the baffles 2 extends into the opening area of ​​the outlet pipes 5.

[0046] Each chamber 3 is connected to a feed pipe 4 and a first nitrogen purge pipe 6. Specifically, the number of feed pipes 4 and first nitrogen purge pipes 6 is the same as the number of inlet pipes 10, such that the feed pipes 4 and first nitrogen purge pipes 6 are connected to the corresponding chamber 3 through inlet pipes 10. More specifically, one end of the inlet pipe 10 is connected to the adsorption tower body 1 and communicates with the corresponding chamber 3, and the other end has two branches, including a first branch and a second branch. The first branch is connected to the corresponding feed pipe 4, and the second branch is connected to the corresponding first nitrogen purge pipe 6.

[0047] Valves 7 are provided on the feed pipe 4, the discharge pipe 5, and the first nitrogen purging pipe 6. The feed pipe 4 is used to deliver the adsorbent to the corresponding chamber 3, and the discharge pipe 5 is used to discharge the adsorbent from the corresponding chamber 3. The other end of the first nitrogen purging pipe 6 is connected to a nitrogen source and is used to blow nitrogen into the surface of the partition 2 in the corresponding chamber 3 to complete the unloading and purging operation of the adsorbent.

[0048] Example 4

[0049] As the preferred embodiment of this utility model, please refer to the appendix to the specification. Figure 1 This utility model includes an adsorption tower for polycrystalline silicon production, comprising an adsorption tower body 1, a nitrogen source, and an adsorbent feeding tank 8. The adsorption tower body 1 is equipped with shut-off valves at both the bottom inlet and the top outlet. The adsorption tower body 1 contains several baffles 2. Each baffle 2 has through holes to allow gas to pass through, but must prevent excessive fall of the upper adsorbent. The baffles 2 divide the interior of the adsorption tower body 1 into several chambers 3 for holding corresponding adsorbents. In this embodiment, the number of baffles 2 and the number of chambers 3 can both be four.

[0050] Each chamber 3 is equipped with an inlet pipe 10 and an outlet pipe 5. One end of the inlet pipe 10 and the outlet pipe 5 are connected to the adsorption tower body 1 and communicate with the corresponding chamber 3. The partition 2 is inclined downward toward the outlet pipe 5, and the lowest point of the partition 2 extends into the opening area of ​​the outlet pipe 5. Preferably, the outlet pipe 5 is also inclined downward. The other ends of the four outlet pipes 5 are connected to the main discharge pipe 13, and the other end of the main discharge pipe 13 is used to connect to a collection device or processing equipment for collecting and bagging the adsorbents.

[0051] Each chamber 3 is connected to a feed pipe 4 and a first nitrogen purging pipe 6. Specifically, in this embodiment, there is one feed pipe 4 and one first nitrogen purging pipe 6. The other ends of the four inlet pipes 10 are connected to the main feed pipe 12. The other end of the main feed pipe 12 is connected to the feed pipe 4 and the first nitrogen purging pipe 6 through two branches. The other end of the feed pipe 4 is connected to the bottom of the adsorbent loading tank 8. The other end of the first nitrogen purging pipe 6 is connected to a nitrogen source and is used to blow nitrogen into the surface of the partition 2 in the corresponding chamber 3 to complete the unloading and purging operation of the adsorbent. Since nitrogen enters the chamber 3 through the inlet pipes 10 during nitrogen purging, the inlet pipes 10 can be connected to the top of the corresponding chamber 3, and the inlet pipe 10 at the end near the chamber 3 is inclined downward toward the partition 2, so that the high-speed airflow hits the partition 2, thereby achieving a good purging effect.

[0052] Furthermore, in order to achieve the delivery of the adsorbent, a second nitrogen purging pipe 9 is provided between the adsorbent feeding tank 8 and the nitrogen source, and the second nitrogen purging pipe 9 is connected to the top of the adsorbent feeding tank 8.

[0053] Furthermore, to ensure the independence of loading, purging, and unloading operations, valves 7 are provided on the feed pipe 4, discharge pipe 5, and first nitrogen purging pipe 6. A second valve 14 is provided on the second nitrogen purging pipe 9. A third valve 11 is also provided on the inlet pipe 10.

[0054] When it is necessary to load material into a specific chamber 3 of the adsorption tower, adsorbent is placed into the adsorbent loading tank 8. Valve 7 on the first nitrogen purge pipe 6 is closed, and valve 7 on the feed pipe 4 and the third valve 11 on the corresponding access pipe 10 of that chamber 3 are opened. Simultaneously, the second valve 14 is opened to inject nitrogen into the adsorbent loading tank 8, creating positive pressure. Under pneumatic conveying, the adsorbent in the adsorbent loading tank 8 enters the main feed pipe 12 through the feed pipe 4 and is then transported to each chamber 3 through the corresponding access pipe 10. Once a chamber 3 is filled, the third valve 11 on the corresponding access pipe 10 is closed. The above steps are repeated to continue feeding material into other chambers 3 until feeding is complete.

[0055] When unloading is required, close the shut-off valve, close valve 7 on the feed pipe 4, and open valve 7 on the first nitrogen purge pipe 6 and the third valve 11 on the inlet pipe 10 corresponding to the chamber 3. Purge the adsorption tower with nitrogen to maintain a certain pressure. Then, open valve 7 on the outlet pipe 5 corresponding to the chamber 3. The adsorbent on the baffle 2 enters the outlet pipe 5 under gravity and pneumatic force, and is then transported to the collection device or treatment equipment via the main discharge pipe 13. Maintain the pressure of the adsorption tower throughout the unloading process. Finally, the first nitrogen purge pipe 6 can purge any remaining adsorbent in the chamber 3. Repeat the above steps to complete the unloading of other chambers 3 sequentially until all chambers 3 are unloaded.

[0056] In this embodiment, there are no restrictions on the packing and unloading sequence of each chamber 3, and they can be selected according to the actual situation.

[0057] In summary, any other corresponding modifications made by those skilled in the art based on the technical solution and concept of this utility model without creative mental effort after reading this utility model document are all within the scope of protection of this utility model.

Claims

1. An adsorption tower for polysilicon production, comprising an adsorption tower body (1), wherein a plurality of partitions (2) are arranged in the adsorption tower body (1) to divide the interior of the adsorption tower body (1) into a plurality of chambers (3) for placing corresponding adsorbents; characterized in that: Each chamber (3) is respectively connected with a feed pipe (4), a discharge pipe (5) and a first nitrogen purge pipe (6); valves (7) are provided on the feed pipe (4), the discharge pipe (5) and the first nitrogen purge pipe (6); the number of the discharge pipes (5) is several, corresponding to each chamber (3) one by one; the partition plate (2) is inclined downward in the direction of the discharge pipe (5), and the lowest point of the partition plate (2) extends into the opening area of the discharge pipe (5); the first nitrogen purge pipe (6) is connected with a nitrogen source and is used to blow nitrogen onto the surface of the partition plate (2) in the corresponding chamber (3) to complete the discharging and purging operations of the adsorbent.

2. The adsorption column for polysilicon production according to claim 1, wherein: It further includes an adsorbent feeding tank (8) connected to the feed pipe (4).

3. The adsorption column for polysilicon production according to claim 2, wherein: A second nitrogen purge pipe (9) is further provided between the adsorbent feeding tank (8) and the nitrogen source, and a second valve (14) is provided on the second nitrogen purge pipe (9).

4. The adsorption tower for polysilicon production according to claim 3, wherein: The feed pipe (4) is connected to the bottom of the adsorbent feeding tank (8), and the second nitrogen purge pipe (9) is connected to the top of the adsorbent feeding tank (8).

5. An adsorption tower for polysilicon production according to claim 3, characterized in that: It further includes access pipes (10) corresponding to each chamber (3) one by one. One end of the access pipe (10) is connected to the adsorption tower body (1) and is communicated with the corresponding chamber (3), and the other end is respectively communicated with the feed pipe (4) and the first nitrogen purge pipe (6).

6. The adsorption tower for polysilicon production according to claim 5, wherein: A third valve (11) is further provided on the access pipe (10).

7. The adsorption tower for polysilicon production according to claim 6, wherein: The access pipe (10) is communicated with the top of the corresponding chamber (3), and the access pipe (10) at the end close to the chamber (3) is inclined downward in the direction of the partition plate (2).

8. An adsorption tower for polysilicon production according to claim 5 or 7, characterized in that: The number of the feed pipes (4) and the first nitrogen purge pipes (6) is the same as that of the access pipes (10); one end of the access pipe (10) away from the chamber (3) has two branches, including a first branch and a second branch; the first branch is connected to the corresponding feed pipe (4), and the second branch is connected to the corresponding first nitrogen purge pipe (6).

9. An adsorption tower for polysilicon production according to claim 5 or 7, characterized in that: It further includes a feeding main pipe (12). The number of the adsorbent feeding tanks (8), the nitrogen sources, the feed pipes (4) and the first nitrogen purge pipes (6) is one respectively; the access pipes (10) of each chamber (3) are respectively communicated with the feeding main pipe (12), and the other end of the feeding main pipe (12) is communicated with the feed pipe (4) and the first nitrogen purge pipe (6) through two branches respectively.

10. An adsorption tower for polysilicon production according to claim 9, characterized in that: It further includes a discharging main pipe (13), and several discharge pipes (5) are respectively connected to the discharging main pipe (13).

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