Automatic fine powder cutting device for cold hydrogenation fluidized bed
By designing an automatic fine powder removal device for the cold hydrogenated fluidized bed, the problem of unreactive fine silicon powder being brought into the rear system was solved, efficient fine powder recovery and improved equipment stability were achieved, and production costs were reduced.
Patent Information
- Application Number
- CN202423194592.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-12-24
AI Technical Summary
In the existing polysilicon production process, unreactive fine silicon powder in the cold hydrogenation fluidized bed is easily carried into the post-processing system by the gas phase, resulting in blockage and scaling of post-system equipment and increased production costs.
A cold hydrogenation fluidized bed fine powder automatic removal device is designed, which includes a fluidized bed, a cyclone separator and a fine powder collection tank. A differential pressure gauge and a valve are used to control the removal and collection of fine powder. Non-reactive fine silicon powder is directly introduced into the fine powder collection tank through a pipeline, and nitrogen purge is used to recover chlorosilane gas and hydrogen to obtain dry fine silicon powder.
It achieves efficient removal and recovery of non-reactive fine silicon powder, reduces the production load of the subsequent system, reduces equipment wear and production costs, simplifies the operating process, and reduces fixed asset investment.
Smart Images
Figure CN223381575U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of polysilicon, and in particular relates to a cold hydrogenated fluidized bed fine powder automatic cutting device. Background Art
[0002] Currently, the main polysilicon production processes in China and abroad are the modified Siemens process and the silane fluidized bed process. Both of these production processes rely on the cold hydrogenation process to produce trichlorosilane, and the fluidized bed is the core component of the cold hydrogenation process. Therefore, an efficient and reliable cold hydrogenation fluidized bed is crucial for polysilicon production. Domestic polysilicon manufacturers often use cyclone separators to prevent silicon powder in the fluidized bed from being entrained into the gas phase and into post-processing. Therefore, for the unreactive fine silicon powder in the fluidized bed, the cyclone separator is often used to destroy the separation effect to remove the unreactive fine silicon powder.
[0003] However, the above-mentioned method of destroying the separation effect of the cyclone separator has the following disadvantages: (1) The unreactive fine silicon powder is carried into the post-processing system along with the post-reaction gas phase, which can cause blockage and scaling of the post-processing heat exchanger, wear of equipment and pipelines, and shorten the operating cycle of the entire cold hydrogenation system. (2) The unreactive fine silicon powder carried into the post-processing system needs to be separated, which increases the production cost of the device. Summary of the Invention
[0004] Purpose of the utility model: The technical problem to be solved by the utility model is to address the deficiencies of the existing technology and provide a device that can directly remove non-reactive fine powder in the dilute phase section of a cold hydrogenation fluidized bed, so as to improve the conversion efficiency and operation stability of the fluidized bed.
[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0006] A cold hydrogenation fluidized bed fine powder automatic cutting device comprises a fluidized bed, a cyclone separator and a fine powder collection tank; the cyclone separator is a group, respectively arranged in the dilute phase section inside the fluidized bed; the fluidized bed is respectively provided with three pressure gauges at the top, middle and bottom, a pressure differential gauge 1 is connected between the top and middle pressure gauges, and a pressure differential gauge 2 is connected between the middle and bottom pressure gauges; the top of the fluidized bed is connected to the fine powder collection tank through the fluidized bed top extraction pipe; the middle of the fluidized bed is connected to the fine powder collection tank through the fluidized bed middle extraction pipe.
[0007] Furthermore, a second pressure gauge is provided on the top of the fluidized bed, and a first pressure gauge is provided on the top of the fine powder collection tank.
[0008] Furthermore, a fine powder collecting tank emptying pipe is provided on the top of the fine powder collecting tank, and the fine powder collecting tank emptying pipe is connected to an external tail gas recovery device.
[0009] Furthermore, a fine powder collecting tank discharge pipe is provided at the bottom of the fine powder collecting tank, and the fine powder collecting tank discharge pipe is connected to the collecting device below.
[0010] Furthermore, the cold hydrogenation fluidized bed fine powder automatic cutting device also includes a nitrogen storage device, which is connected to the fine powder collection tank through a first nitrogen purge pipe, and nitrogen is purged into the fine powder collection tank through the first nitrogen purge pipe.
[0011] Furthermore, the nitrogen storage device is connected to the discharge pipe of the fine powder collection tank through a second nitrogen purge pipe, and nitrogen is purged into the discharge pipe of the fine powder collection tank through the second nitrogen purge pipe.
[0012] Furthermore, a first valve is provided on the production pipeline at the top of the fluidized bed; and a second valve is provided on the production pipeline in the middle of the fluidized bed.
[0013] Furthermore, a third valve is provided on the emptying pipe of the fine powder collection tank.
[0014] Furthermore, the fine powder collecting tank is provided with a level meter.
[0015] Furthermore, the cyclone separator is connected to a subsequent system through a cyclone separator discharge pipe. Beneficial effects
[0016] (1) This device removes the unreactive fine silicon powder from the fluidized bed directly without passing through a cyclone separator or post-system facilities, and recycles the removed silicon powder from the fluidized bed. This reduces the excessive production load on the post-system caused by the removal of unreactive fine silicon powder. By utilizing the fluid properties of solids in a fluidized state, the unreactive fine silicon powder in the fluidized bed is passed through a pipeline into a fine powder collection tank. Finally, the chlorosilane gas and hydrogen in the fine powder collection tank are exhausted to obtain dry fine silicon powder, which can be recycled.
[0017] (2) This device can remove the fine powder generated in the cold hydrogenation fluidized bed, separate it, and recycle it. Compared with other fine powder separation devices, this device is simpler and has a smaller fixed asset investment. It can be automatically controlled by a DCS system, requiring only the setting of process parameters, which greatly reduces the workload of operators. This device removes fine silicon powder in the high-temperature section of the fluidized bed, significantly reducing production costs compared to the post-system condensation separation method. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.
[0019] Figure 1 It is a structural diagram of the device of the utility model.
[0020] Wherein, each reference numeral represents:
[0021] 1- fluidized bed; 2- cyclone separator; 3- fine powder collection tank; 4- collection device;
[0022] 101 - Fluidized bed top extraction pipeline; 102 - Fluidized bed middle extraction pipeline; 103 - Fine powder collection tank emptying pipeline; 104 - Fine powder collection tank discharge pipeline; 105 - First nitrogen purge pipeline; 106 - Second nitrogen purge pipeline; 107 - Cyclone separator discharge pipeline;
[0023] 201 - first valve; 202 - second valve; 203 - third valve; 204 - fourth valve. DETAILED DESCRIPTION
[0024] The present invention can be better understood according to the following embodiments.
[0025] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for the understanding and reading of those familiar with this technology. They are not used to limit the conditions for the implementation of the utility model and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the utility model without affecting the efficacy and purpose of the utility model. At the same time, terms such as "upper", "lower", "front", "back", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the utility model. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the utility model without substantially changing the technical content.
[0026] The utility model discloses an automatic fine powder removal device for a cold hydrogenated fluidized bed, comprising a fluidized bed 1, a cyclone separator 2 and a fine powder collection tank 3; the cyclone separator 2 is a group and is respectively arranged in the dilute phase section inside the fluidized bed 1; the fluidized bed 1 is respectively provided with three pressure gauges at the top, middle and bottom, a differential pressure gauge 1 is connected between the top and middle pressure gauges, and a differential pressure gauge 2 is connected between the middle and bottom pressure gauges; the top of the fluidized bed 1 is connected to the fine powder collection tank 3 through a fluidized bed top extraction pipe 101; the middle of the fluidized bed 1 is connected to the fine powder collection tank 3 through a fluidized bed middle extraction pipe 102.
[0027] Wherein, a second pressure gauge is provided on the top of the fluidized bed 1, and a first pressure gauge is provided on the top of the fine powder collecting tank 3.
[0028] A fine powder collecting tank emptying pipe 103 is provided on the top of the fine powder collecting tank 3 , and is connected to an external tail gas recovery device through the fine powder collecting tank emptying pipe 103 .
[0029] A fine powder collecting tank discharge pipe 104 is provided at the bottom of the fine powder collecting tank 3 , and the fine powder collecting tank discharge pipe 104 is connected to the collecting device 4 below.
[0030] The cold hydrogenation fluidized bed fine powder automatic cutting device also includes a nitrogen storage device, which is connected to the fine powder collection tank 3 through a first nitrogen purge pipe 105, and purges nitrogen into the fine powder collection tank 3 through the first nitrogen purge pipe 105.
[0031] The nitrogen storage device is connected to the fine powder collection tank discharge pipe 104 through the second nitrogen purge pipe 106 , and nitrogen is purged into the fine powder collection tank discharge pipe 104 through the second nitrogen purge pipe 106 .
[0032] A first valve 201 is provided on the production pipe 101 at the top of the fluidized bed; a second valve 202 is provided on the production pipe 102 in the middle of the fluidized bed.
[0033] A third valve 203 is provided on the fine powder collection tank emptying pipe 103 .
[0034] A level meter is provided on the fine powder collecting tank 3 for monitoring the fine powder level in the fine powder collecting tank.
[0035] The cyclone separator 2 is connected to a subsequent system via a cyclone separator discharge pipe 107 .
[0036] This device utilizes the properties of solids in a fluidized state, allowing the unreactive fine silicon powder in the fluidized bed to be passed through a pipeline into a fine powder collection tank. Finally, the chlorosilane gas and hydrogen in the fine powder collection tank are exhausted to obtain dry fine silicon powder for recycling. The specific process flow is as follows:
[0037] S1. Install a differential pressure gauge 1 in the dilute phase section of the fluidized bed, and measure the fine powder content in the fluidized bed by the value displayed on the differential pressure gauge 1;
[0038] S2. When the pressure differential gauge 1 in the dilute phase section of the fluidized bed reaches the set value, the first valve 201 is opened, and the mixed gas carrying fine silicon powder enters the fine powder collection tank 3 through the production pipeline 101 at the top of the fluidized bed. When the values of pressure gauge 1 and pressure gauge 2 are the same, the first valve 201 is closed.
[0039] S3, after the fine powder collection tank 3 is left standing for a period of time, the third valve 203 is opened, and the chlorosilane gas and hydrogen in the tank are discharged to the tail gas recovery device through the fine powder collection tank exhaust pipe; 103.
[0040] S4. Repeat steps S2 and S3 until the value of the pressure differential gauge 1 reaches the process requirement or the level gauge of the fine powder collection tank 3 reaches the maximum value required by the process indicator.
[0041] S5. Open the fourth valve 204 to introduce nitrogen into the fine powder collection tank 3 through the first nitrogen purge pipe 105 for displacement, and displace the chlorosilane gas and hydrogen in the tank out of the fine powder collection tank 3 through the fine powder collection tank emptying pipe 103.
[0042] S6. The fine silicon powder collected is discharged into the collecting device 4 through the fine powder collecting tank discharge pipe 104 at the bottom of the fine powder collecting tank 3 for recycling.
[0043] S7. When the pressure differential gauge 2 reaches the process requirement, the second valve 202 is opened, and the mixed gas carrying fine silicon powder enters the fine powder collection tank 3 through the production pipeline 102 in the middle of the fluidized bed. When the values of the pressure gauge 1 and the pressure gauge 2 are the same, the second valve 202 is closed.
[0044] S8. After the fine powder collecting tank 3 is left to stand for a period of time, the third valve 203 is opened to discharge the chlorosilane gas and hydrogen in the tank to the tail gas recovery device through the fine powder collecting tank emptying pipe 103.
[0045] S9. Repeat steps S7 and S8 until the value of the pressure differential gauge 1 reaches the process requirement or the level gauge of the fine powder collection tank 3 reaches the maximum value required by the process indicator.
[0046] S10: Same as step 5.
[0047] This utility model provides a concept and method for an automatic fine powder removal device for a cold hydrogenation fluidized bed. There are many methods and approaches to implement this technical solution. The above is only a preferred embodiment of the utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the utility model, and such improvements and modifications should also be considered within the scope of protection of the utility model. Any components not specified in this embodiment can be implemented using existing technologies.
Claims
1. A cold hydrogenation fluidized bed fine powder automatic cutting device, characterized in that: The invention comprises a fluidized bed (1), a cyclone separator (2) and a fine powder collecting tank (3); the cyclone separator (2) is a group and is respectively arranged in the dilute phase section inside the fluidized bed (1); the fluidized bed (1) is provided with three pressure gauges at the top, middle and bottom, respectively, a differential pressure gauge 1 is connected between the top and middle pressure gauges, and a differential pressure gauge 2 is connected between the middle and bottom pressure gauges; the top of the fluidized bed (1) is connected to the fine powder collecting tank (3) through a fluidized bed top extraction pipe (101); the middle of the fluidized bed (1) is connected to the fine powder collecting tank (3) through a fluidized bed middle extraction pipe (102).
2. The cold hydrogenation fluidized bed fine powder automatic cutting device according to claim 1, characterized in that: A second pressure gauge is provided on the top of the fluidized bed (1), and a first pressure gauge is provided on the top of the fine powder collecting tank (3).
3. The automatic fine powder cutting device for cold hydrogenated fluidized bed according to claim 1, characterized in that: A fine powder collection tank emptying pipe (103) is provided on the top of the fine powder collection tank (3), and is connected to an external tail gas recovery device through the fine powder collection tank emptying pipe (103).
4. The cold hydrogenation fluidized bed fine powder automatic cutting device according to claim 1, characterized in that: A fine powder collecting tank discharge pipe (104) is provided at the bottom of the fine powder collecting tank (3), and is connected to the collecting device (4) below via the fine powder collecting tank discharge pipe (104).
5. The automatic fine powder cutting device for cold hydrogenation fluidized bed according to claim 4, characterized in that: It also includes a nitrogen storage device, which is connected to the fine powder collection tank (3) through a first nitrogen purge pipe (105) and purges nitrogen into the fine powder collection tank (3) through the first nitrogen purge pipe (105).
6. The cold hydrogenation fluidized bed fine powder automatic cutting device according to claim 5, characterized in that: The nitrogen storage device is connected to the fine powder collection tank discharge pipe (104) via a second nitrogen purge pipe (106), and nitrogen is purged into the fine powder collection tank discharge pipe (104) via the second nitrogen purge pipe (106).
7. The automatic fine powder cutting device for cold hydrogenated fluidized bed according to claim 1, characterized in that: A first valve (201) is provided on the extraction pipe (101) at the top of the fluidized bed; and a second valve (202) is provided on the extraction pipe (102) in the middle of the fluidized bed.
8. The automatic fine powder removal device for a cold hydrogenated fluidized bed according to claim 3, characterized in that: A third valve (203) is provided on the fine powder collection tank emptying pipe (103).
9. The cold hydrogenation fluidized bed fine powder automatic cutting device according to claim 1, characterized in that: The fine powder collecting tank (3) is provided with a material level meter.
10. The cold hydrogenation fluidized bed fine powder automatic cutting device according to claim 1, characterized in that: The cyclone separator (2) is connected to a subsequent system via a cyclone separator discharge pipe (107).