Polycrystalline silicon cold hydrogenation device

Abstract

The utility model discloses a polycrystalline silicon cold hydrogenation device which comprises a Venturi dust remover, a settling tank, a dust removal tower and a quench tower, the front end of the venturi dust remover is connected with the fluidized bed for discharging, and the rear end of the venturi dust remover is connected to the settling tank; the top of the settling tank is connected to the dust removal tower through a gas phase pipe, and the bottom of the settling tank is connected to a slag slurry treatment system through a slag discharge pipeline; the tower top of the dust removal tower is connected to the quench tower through a gas phase pipe, and the tower kettle of the dust removal tower is connected to a slag slurry treatment system through a slag discharge pipeline. The filler type rectifying tower is additionally arranged in front of the quench tower for dust removal, so that the solid content of a tower kettle of the quench tower can be effectively reduced, the pressure difference of a filter at an inlet of a tower kettle pump is reduced, the wear rate of silicon powder to a pipeline is reduced, and the parking risk caused by related faults of the tower kettle pump of the quench tower is reduced, so that the operation stability of the system is improved.

Description

Technical Field

[0001] The utility model belongs to the field of polysilicon production, and in particular relates to a polysilicon cold hydrogenation device. Background Art

[0002] At present, in the cold hydrogenation device of polysilicon, the function of the quenching tower is to remove dust and cool the materials. After the materials entering the quenching tower are dedusted by the Venturi device, they still contain a small amount of silicon powder, resulting in a solid content of about 0.2% in the quenching tower kettle. This part of the material is pressurized by the kettle pump as a spray for the quenching tower and the Venturi device, but due to the high solid content, the operation of the kettle pump is unstable, the pump impeller and volute wear quickly, the service life is short, and frequent maintenance affects the smooth operation of the entire cold hydrogenation system. Therefore, the current process must be changed to ensure that the materials at the inlet of the kettle pump are clean and the pump can operate stably for a long period of time. Utility Model Content

[0003] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a cold hydrogenation device for polysilicon in view of the deficiencies in the prior art, to reduce the solid content of materials in the quench tower and kettle in the polysilicon production process, to protect the quench tower reflux pump, to reduce the risk of system shutdown, and to ensure long-term operation of the system.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0005] A polysilicon cold hydrogenation device comprises a venturi dust collector, a settling tank, a dust removal tower and a quenching tower; the front end of the venturi dust collector is connected to the fluidized bed discharge, and the rear end of the venturi dust collector is connected to the settling tank; the top of the settling tank is connected to the dust removal tower through a gas phase pipe, and the bottom of the settling tank is connected to a slag slurry treatment system through a slag discharge pipeline; the top of the dust removal tower is connected to the quenching tower through a gas phase pipe, and the bottom of the dust removal tower is connected to the slurry treatment system through a slag discharge pipeline to discharge liquid materials and solids.

[0006] Furthermore, the dust removal tower adopts a packed distillation tower, and the top of the settling tank is connected to the material feed port at the bottom of the packed distillation tower through a gas phase pipe, and enters the tower through a distributor.

[0007] Specifically, the dust removal tower is connected to the lower part of the quenching tower through a gas phase outlet pipe at the top of the tower, and the gas generated by the dust removal tower is sent to the quenching tower for condensation.

[0008] Furthermore, the top of the quenching tower is connected to a reflux tank through a gas phase pipe for separation; a part of the discharge from the reflux tank is returned to the quenching tower through a reflux pipe, and the other part is sent to a post-processing system through a pipeline.

[0009] Furthermore, a reflux pump is provided on the reflux pipeline between the reflux tank and the quenching tower.

[0010] Furthermore, a discharge pipeline is provided at the bottom of the kettle of the quenching tower, and the discharge pipeline is reconnected to the upper part of the quenching tower for spraying.

[0011] Furthermore, a tower bottom pump for pressurization is arranged on the discharge pipeline.

[0012] Furthermore, the discharge pipeline is located at the rear end of the tower kettle pump, and is also provided with a first branch pipe, which is connected to the top spray port and the middle spray port of the dust removal tower, and is sprayed through a distributor.

[0013] Furthermore, the discharge pipeline is located at the rear end of the tower kettle pump, and is also provided with a second branch pipe, and the second branch pipe is connected to the Venturi dust collector for spraying.

[0014] Furthermore, the rear end of the second branch pipe is respectively connected to the feed end and the discharge end of the Venturi dust collector through two parallel branch pipes.

[0015] Beneficial effects:

[0016] This device aims to solve the problem of unstable system operation caused by excessively high solid content in the kettle of the quenching tower in the polysilicon cold hydrogenation production process. By adding a packed distillation tower in front of the quenching tower for dust removal, the solid content in the kettle of the quenching tower can be effectively reduced, the pressure difference of the inlet filter of the kettle pump can be reduced, the wear rate of silicon powder on the pipeline can be reduced, and the risk of shutdown caused by malfunctions related to the kettle pump of the quenching tower can be reduced, thereby improving the operation stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0018] Figure 1 It is a schematic diagram of the overall structure of the device.

[0019] Figure 2 It is a structural schematic diagram of the dust removal tower of this device.

[0020] Wherein, each reference numeral represents:

[0021] 10-Venturi dust collector; 20-settling tank; 30-dust removal tower; 301-material feed port; 302-distributor; 303-slag discharge pipeline; 304-middle spray port; 305-tower top gas phase outlet pipe; 306-top spray port; 40-quenching tower; 50-reflux tank; 60-reflux pump; 70-tower kettle pump;

[0022] S1- fluidized bed; S2- slurry treatment system; S3- post-treatment system. DETAILED DESCRIPTION

[0023] The present invention can be better understood according to the following embodiments.

[0024] The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "front", "back", "middle" and so on 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. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0025] like Figure 1 As shown, the polysilicon cold hydrogenation device includes a venturi dust collector 10, a settling tank 20, a dust removal tower 30 and a quenching tower 40; the front end of the venturi dust collector 10 is connected to the fluidized bed S1 discharge, and the rear end of the venturi dust collector 10 is connected to the settling tank 20; the top of the settling tank 20 is connected to the dust removal tower 30 through a gas phase pipe, and the bottom of the settling tank 20 is connected to the slurry treatment system S2 through a slag discharge pipeline; the top of the dust removal tower 30 is connected to the quenching tower 40 through a gas phase pipe, and the bottom of the dust removal tower 30 is connected to the slurry treatment system S2 through a slag discharge pipeline 303 to discharge liquid materials and solids.

[0026] The dust removal tower 30 is a packed distillation tower, and the top of the settling tank 20 is connected to the material feed port 301 at the bottom of the packed distillation tower through a gas phase pipe, and enters the tower through a distributor.

[0027] The dust removal tower 30 is connected to the lower part of the quenching tower 40 through the tower top gas phase outlet pipe 305, and the gas generated by the dust removal tower 30 is sent into the quenching tower 40 for condensation.

[0028] The top of the quench tower 40 is connected to the reflux tank 50 through a gas phase pipe for separation; a part of the discharge from the reflux tank 50 is returned to the quench tower 40 through a reflux pipeline, and the other part is sent to the post-processing system S3 through a pipeline.

[0029] A reflux pump 60 is provided on the reflux pipeline between the reflux tank 50 and the quench tower 40 .

[0030] A discharge pipeline is provided at the bottom of the kettle of the quench tower 40 , and the discharge pipeline is reconnected to the upper part of the quench tower 40 for spraying.

[0031] A tower bottom pump 70 for pressurization is provided on the discharge pipeline.

[0032] The discharge pipeline is located at the rear end of the tower bottom pump 70, and is also provided with a first branch pipe and a second branch pipe. The first branch pipe is connected to the top spray port 306 and the middle spray port 304 of the dust removal tower 30, and sprays through the distributor 302. The second branch pipe is connected to the venturi dust collector 10 for spraying.

[0033] The rear end of the second branch pipe is respectively connected to the feed end and the discharge end of the Venturi dust collector 10 through two parallel branch pipes.

[0034] The specific process flow of the device is as follows: silicon powder and silicon tetrachloride react in the fluidized bed S1 to generate trichlorosilane, and then the material enters the venturi dust collector 10 for dust removal, and the separated particles settle and accumulate at the bottom of the settling tank 20, and then are discharged to the slurry treatment system S2 through the slag discharge pipeline for treatment. However, since the venturi dust collector 10 is only suitable for dust removal of large particles, and there are fine silicon powders with smaller particles in this system, the venturi dust collector 10 cannot completely remove the silicon powder in the material, and the gas discharged from the upper part of the settling tank 20 contains a small amount of silicon powder. If this part of the material directly enters the quenching tower 40, the silicon powder in the tower bottom will cause certain wear on the tower bottom pump 70, making it difficult for the tower bottom pump 70 of the quenching tower 40 to be used for a long period of time, resulting in abnormal operation.

[0035] In order to solve this problem, the device adds a dust removal tower 30 in front of the quench tower 40, and the dust removal tower 30 combines the functions of distillation and dust removal. The 145°C gaseous material after dust removal by the Venturi dust collector 10 enters the lower part of the dust removal tower 30. In the dust removal tower 30, the chlorosilane in the tower bottom material, as a light component, is heated and vaporized and rises to contact the liquid reflux at the top of the tower on the surface of the packing to exchange heat and materials, thereby separating the chlorosilane and silicon powder. Since the melting point of silicon powder is higher than 1000°C, it cannot be vaporized in this system, so it will be eluted and remain in the tower bottom. The clean gaseous chlorosilane enters the quench tower 40 from the top of the tower for cooling. The material containing silicon powder in the dust removal tower bottom is discharged to the slag slurry treatment system S2 through the slag discharge pipeline for treatment.

[0036] In the quench tower 40, the top material is condensed and enters the reflux tank 50. A portion of the material in the reflux tank 50 is returned to the upper part of the quench tower 40 through the reflux pump 60 for spraying, and the other portion is sent to the post-processing system S3 through a pipeline for further separation. The bottom material of the quench tower 40 is pressurized by the bottom pump 70 and used as spray for the venturi dust collector 10, the quench tower 40 and the dust removal tower 30.

[0037] This device can effectively reduce the solid content of the quench tower kettle, reduce the pressure difference of the inlet filter of the kettle pump, reduce the wear rate of silicon powder on the pipeline, and reduce the shutdown risk caused by quench tower kettle pump-related failures, thereby improving the operating stability of the system.

[0038] The utility model provides a concept and method of a polysilicon cold hydrogenation device. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A polysilicon cold hydrogenation device, characterized in that: The invention comprises a venturi dust collector (10), a settling tank (20), a dust removal tower (30) and a quenching tower (40); the front end of the venturi dust collector (10) is connected to the discharge of the fluidized bed (S1), and the rear end of the venturi dust collector (10) is connected to the settling tank (20); the top of the settling tank (20) is connected to the dust removal tower (30) through a gas phase pipe, and the bottom of the settling tank (20) is connected to a slurry treatment system (S2) through a slag discharge pipeline; the top of the dust removal tower (30) is connected to the quenching tower (40) through a gas phase pipe, and the bottom of the dust removal tower (30) is connected to the slurry treatment system (S2) through a slag discharge pipeline (303).

2. The polysilicon cold hydrogenation device according to claim 1, characterized in that: The dust removal tower (30) is a packed distillation tower, and the top of the settling tank (20) is connected to the material feed port (301) at the bottom of the packed distillation tower through a gas phase pipe, and enters the tower through a distributor.

3. The polysilicon cold hydrogenation device according to claim 1, characterized in that: The dust removal tower (30) is connected to the lower part of the quenching tower (40) via a gas phase outlet pipe (305) at the top of the tower.

4. The polysilicon cold hydrogenation device according to claim 1, characterized in that: The top of the quenching tower (40) is connected to the reflux tank (50) through a gas phase pipe for separation; part of the discharge from the reflux tank (50) is returned to the quenching tower (40) through a reflux pipeline, and the other part is sent to a post-processing system (S3) through a pipeline.

5. The polysilicon cold hydrogenation device according to claim 4, characterized in that: A reflux pump (60) is provided on the reflux pipeline between the reflux tank (50) and the quenching tower (40).

6. The polysilicon cold hydrogenation device according to claim 1, characterized in that: A discharge pipeline is provided at the bottom of the kettle of the quenching tower (40), and the discharge pipeline is reconnected to the upper part of the quenching tower (40) for spraying.

7. The polysilicon cold hydrogenation device according to claim 6, characterized in that: The discharge pipeline is provided with a tower bottom pump (70) for increasing pressure.

8. The polysilicon cold hydrogenation device according to claim 6, characterized in that: The discharge pipeline is located at the rear end of the tower bottom pump (70) and is also provided with a first branch pipe, which is connected to the top spray port (306) and the middle spray port (304) of the dust removal tower (30) and is sprayed through the distributor (302).

9. The polysilicon cold hydrogenation device according to claim 7, characterized in that: The discharge pipeline is located at the rear end of the tower bottom pump (70), and is also provided with a second branch pipe, which is connected to the Venturi dust collector (10) for spraying.

10. The polysilicon cold hydrogenation device according to claim 9, characterized in that: The rear end of the second branch pipe is respectively connected to the feed end and the discharge end of the Venturi dust collector (10) through two parallel branch pipes.

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