Anti-disproportionation reaction rectification transformation device for polycrystalline silicon production

Abstract

The utility model discloses an anti-disproportionation reaction rectification transformation device used in polycrystalline silicon production, which comprises a mixer, a heater, an anti-disproportionation fixed bed reactor and a reaction rectification tower, the mixer receives dichlorosilane and liquid silicon tetrachloride and mixes the dichlorosilane and the liquid silicon tetrachloride to form a mixture, the mixer is connected with the heater, the heater heats the mixture, and the reaction rectification tower is connected with the anti-disproportionation fixed bed reactor. The method comprises the following steps of: heating a mixture, conveying the heated mixture to an anti-disproportionation fixed bed reactor, respectively connecting the anti-disproportionation fixed bed reactor with a heater and a reaction rectifying tower, carrying out anti-disproportionation reaction on the mixture in the anti-disproportionation fixed bed reactor under the action of a catalyst, connecting a tower body of the reaction rectifying tower to a mixer, and extracting trichlorosilane from the tower top of the reaction rectifying tower, silicon tetrachloride which does not participate in the anti-disproportionation reaction in the anti-disproportionation reaction is extracted from the tower body of the reactive distillation tower and is conveyed to the mixer to serve as a raw material again, and impurities generated in the reaction are discharged from the tower kettle of the reactive distillation tower. According to the device provided by the utility model, the safety and operability of the anti-disproportionation reaction are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of polysilicon production, and in particular relates to an anti-disproportionation reaction distillation transformation device used in polysilicon production. Background Art

[0002] In the production of polysilicon, the deproportionation system is an important part of distillation. Its main function is to consume the reduction and hydrogenation by-product dichlorosilane. Dichlorosilane contains non-metallic impurities such as B and P. Since the catalyst used in the deproportionation has a certain adsorption function, the surface of the catalyst will be covered with impurities such as B and P after running for a period of time, making it impossible for chlorosilane to effectively contact the catalyst and reduce the reaction efficiency. If dichlorosilane is not converted, it will be enriched in the system. After enrichment, the distillation reduction system and the hydrogenation system cannot operate normally, and finally the system cannot operate and shut down. Since the deproportionation system generally uses a reaction distillation tower, the conversion rate of the reaction distillation tower continues to drop to 60% after two years of operation. It is usually necessary to replace the deproportionation tower with a qualified one, clean out the catalyst in the reaction distillation tower, and reinstall a new catalyst. However, the deproportionation catalyst is flammable and explosive, and the risk of personnel operation is very high. In addition, the operability of replacing the reaction distillation catalyst is poor, and there are serious safety hazards.

[0003] To this end, the present application proposes an anti-disproportionation reaction distillation modification device for use in polysilicon production to solve the above-mentioned problems. Utility Model Content

[0004] In order to solve the above problems existing in the prior art, the utility model is implemented through the following technical solutions:

[0005] The utility model provides a device for transforming anti-disproportionation reaction distillation in polysilicon production, comprising a mixer, a heater, an anti-disproportionation fixed bed reactor and a reaction distillation tower, wherein the mixer can receive liquid dichlorosilane and liquid silicon tetrachloride, mix the liquid dichlorosilane and the liquid silicon tetrachloride to form a mixture of dichlorosilane and silicon tetrachloride, the mixer is connected to the heater, the heater can heat the mixture to a preset temperature, and transmit the heated mixture to the anti-disproportionation fixed bed reactor, the input end of the anti-disproportionation fixed bed reactor The heater is connected, and the output end of the anti-disproportionation fixed-bed reactor is connected to the reaction distillation tower. The mixture undergoes an anti-disproportionation reaction in the anti-disproportionation fixed-bed reactor under the action of a catalyst to generate trichlorosilane. The tower body of the reaction distillation tower is connected to the mixer. The top of the reaction distillation tower extracts trichlorosilane for distillation. The tower body of the reaction distillation tower extracts silicon tetrachloride that does not participate in the anti-disproportionation reaction, and transmits the silicon tetrachloride that does not participate in the anti-disproportionation reaction to the mixer as a raw material for the anti-disproportionation reaction. The bottom of the reaction distillation tower discharges impurities generated in the reaction.

[0006] In one embodiment of the utility model, the tower body of the reaction distillation tower is connected to the mixer via a pumping pipeline, and the pumping pipeline is provided with a silicon tetrachloride delivery pump, and the silicon tetrachloride delivery pump pumps the silicon tetrachloride that does not participate in the anti-disproportionation reaction to the mixer.

[0007] In one embodiment of the utility model, a temperature sensor is further included. The temperature sensor can collect the real-time temperature of the heater. When the real-time temperature is collected, the heater can be controlled to perform temperature compensation according to the real-time temperature.

[0008] In one embodiment of the utility model, a micro control unit is further included, and the micro control unit is respectively connected to the heater and the temperature sensor. When the micro control unit obtains the real-time temperature collected by the temperature sensor, the micro control unit controls the heater to perform temperature compensation according to the real-time temperature.

[0009] In one embodiment of the utility model, the bottom of the reaction distillation tower is connected to a cold hydrogenation slag slurry flash tank, and the impurities enter the cold hydrogenation slag slurry flash tank for cold hydrogenation.

[0010] In one embodiment of the present invention, the mass ratio of the liquid dichlorosilane to the liquid silicon tetrachloride is 1:5.

[0011] In one embodiment of the present invention, when the heated mixture is transferred to the anti-disproportionation fixed bed reactor, the reaction temperature of the anti-disproportionation fixed bed reactor is 65°C.

[0012] In one embodiment of the utility model, when the mixture undergoes an anti-disproportionation reaction in the anti-disproportionation fixed bed reactor under the action of a catalyst, and all the materials after the reaction are transferred to the reaction distillation tower, the reaction temperature of the reaction distillation tower is 70°C and the reaction pressure is 80kpa.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] The anti-disproportionation reaction distillation modification device for polysilicon production provided by the utility model transfers the reaction process to the anti-disproportionation fixed bed reactor, uses bulk catalyst in the anti-disproportionation fixed bed reactor, uses the fixed bed to carry out the anti-disproportionation reaction, uses the reaction distillation tower as a separation tower, enters the next process after obtaining the target product, and the excess reactants are circulated into the mixer to participate in the reaction. Since the catalyst in the anti-disproportionation fixed bed reactor can be updated in time according to demand, the conversion rate can be increased to 99%, thereby improving the conversion efficiency. And the anti-disproportionation reaction distillation modification device provided by the utility model does not need to replace the original reaction distillation tower device, by adding an anti-disproportionation fixed bed reactor, a mixer and a heater in front of the reaction distillation tower device, changing the operation mode of the reaction distillation, and does not need to clean the anti-disproportionation catalyst to be replaced in the original reaction distillation tower, avoiding the personnel operation risk caused by cleaning the catalyst out of the anti-disproportionation distillation tower in conventional operation, and only needs to be put into the equipment once, which can ensure long-term operation and increase safety and operability.

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an anti-disproportionation reaction distillation modification device used in polysilicon production provided by an embodiment of the utility model.

[0017] Description of reference numerals:

[0018] 10-mixer; 20-heater; 30-anti-disproportionation fixed bed reactor; 40-silicon tetrachloride delivery pump; 50-reactive distillation tower. DETAILED DESCRIPTION

[0019] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the present invention, the scheme according to the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0020] The above and other technical contents, features and effects of the utility model are clearly presented in the following detailed description of the specific implementation mode in conjunction with the accompanying drawings. Through the description of the specific implementation mode, the technical means and effects adopted by the utility model to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation, and are not used to limit the technical solution of the utility model.

[0021] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the article or device including the elements.

[0022] See also Figure 1 , Figure 1 It is a structural schematic diagram of an anti-disproportionation reaction distillation modification device for polysilicon production provided by an embodiment of the utility model. The direction indicated by the arrow in the figure is the material flow direction. The anti-disproportionation reaction distillation modification device for polysilicon production includes a mixer 10, a heater 20, an anti-disproportionation fixed bed reactor 30 and a reaction distillation tower 50.

[0023] Specifically, the mixer 10 can receive liquid dichlorosilane and liquid silicon tetrachloride, mix the liquid dichlorosilane and liquid silicon tetrachloride to form a mixture of dichlorosilane and silicon tetrachloride, the mixer 10 is connected to the heater 20, the heater 20 can heat the mixture to a preset temperature, and transmit the heated mixture to the anti-disproportionation fixed bed reactor 30, the input end of the anti-disproportionation fixed bed reactor 30 is connected to the heater 20, the output end of the anti-disproportionation fixed bed reactor 30 is connected to the reaction distillation tower 50, and the mixture Under the action of the catalyst, an anti-disproportionation reaction occurs in the anti-disproportionation fixed bed reactor 30 to generate trichlorosilane. The tower body of the reaction distillation tower 50 is connected to the mixer 10. The trichlorosilane is extracted from the top of the reaction distillation tower 50 for distillation. The tower body of the reaction distillation tower 50 extracts silicon tetrachloride that does not participate in the anti-disproportionation reaction, and the silicon tetrachloride that does not participate in the anti-disproportionation reaction is transferred to the mixer 10 and used as a raw material for the anti-disproportionation reaction again, thereby improving the utilization rate of the raw materials. The bottom of the reaction distillation tower 50 discharges impurities generated in the reaction.

[0024] Furthermore, the tower body of the reaction distillation tower 50 is connected to the mixer 10 via a pumping pipeline, and the pumping pipeline is provided with a silicon tetrachloride delivery pump 40 , and the silicon tetrachloride delivery pump 40 pumps silicon tetrachloride that has not participated in the anti-disproportionation reaction to the mixer 10 .

[0025] Furthermore, a temperature sensor is included, and the temperature sensor can collect the real-time temperature of the heater 20. When the real-time temperature is collected, the heater 20 can be controlled to perform temperature compensation according to the real-time temperature.

[0026] Further, the anti-disproportionation reaction distillation modification device also includes a microcontroller unit (MCU), which is respectively connected to the heater and the temperature sensor. When the microcontroller obtains the real-time temperature collected by the temperature sensor, the microcontroller controls the heater to perform temperature compensation according to the real-time temperature. In this embodiment, the MCU and the temperature sensor are not shown in the figure. The MCU performs temperature compensation on the heater according to the real-time temperature collected by the temperature sensor, which can more accurately control the temperature required before the anti-disproportionation reaction, thereby improving the anti-disproportionation reaction efficiency.

[0027] Furthermore, the bottom of the reaction distillation tower 50 is connected to a cold hydrogenation slag slurry flash tank, and impurities enter the cold hydrogenation slag slurry flash tank for cold hydrogenation, thereby avoiding environmental pollution caused by impurities generated in the anti-disproportionation reaction.

[0028] Furthermore, the mass ratio of liquid dichlorosilane to liquid silicon tetrachloride is 1:5.

[0029] Further, silicon tetrachloride and dichlorosilane undergo an anti-disproportionation reaction in an anti-disproportionation fixed bed reactor under the action of a catalyst, and after the reaction is completed, the mass ratio of silicon tetrachloride to trichlorosilane is 2:3. Specifically, in the anti-disproportionation reaction, silicon tetrachloride is in excess, and after the anti-disproportionation reaction is completed, the mass ratio of silicon tetrachloride to trichlorosilane is 2:3.

[0030] Preferably, when the heated mixture is transferred to the anti-disproportionation fixed bed reactor 30, the reaction temperature of the anti-disproportionation fixed bed reactor 30 is 65°C.

[0031] Preferably, when the mixture of dichlorosilane and silicon tetrachloride undergoes a disproportionation reaction in a fixed-bed reactor under the action of a catalyst, and all the materials after the reaction are transferred to the reaction distillation tower, the reaction temperature of the reaction distillation tower 50 is 70° C. and the reaction pressure is 80 kPa. In this embodiment, all the materials after the reaction include trichlorosilane, silicon tetrachloride that does not participate in the disproportionation reaction, and impurities generated in the reaction.

[0032] The following is a description of the working process of the anti-disproportionation reaction distillation modification device provided in this embodiment:

[0033] S10, mixing silicon dihydrogen dichloride and silicon tetrachloride in a mixer in advance in polysilicon production;

[0034] Specifically, the dichlorosilane and silicon tetrachloride are both in liquid form, and the liquid dichlorosilane and silicon tetrachloride are mixed to form a mixture of dichlorosilane and silicon tetrachloride. This embodiment uses liquid raw materials for mixing to avoid the high standard requirements of gaseous raw materials on pipelines, and the problem of large amounts of raw material leakage and pollution caused by pipeline leakage.

[0035] S20, the mixture of dichlorosilane and silicon tetrachloride enters the heater for heating, and the heater is heated to a preset temperature based on real-time temperature control of the temperature sensor;

[0036] The anti-disproportionation reaction distillation modification device provided in this embodiment can more accurately control the reaction temperature and perform temperature compensation through the temperature sensor.

[0037] S30, the heated mixture is passed into an anti-disproportionation fixed bed for anti-disproportionation reaction;

[0038] The anti-disproportionation reaction distillation modification device provided in this embodiment moves the reaction section of the reaction distillation to the anti-disproportionation fixed-bed reactor outside the distillation tower. Even if the catalyst fails in the later stage, it is only necessary to discharge the catalyst in the fixed bed into the water, thus avoiding the operating risks of personnel caused by cleaning the catalyst in the reaction distillation tower, ensuring the safety of the reaction and improving the reaction efficiency.

[0039] S40, the product after the reaction is separated into components through the original reaction distillation tower, and the raw materials that have not participated in the reaction are transferred to the mixer to re-participate in the anti-disproportionation reaction.

[0040] Specifically, the product after the reaction can enter the original reaction distillation tower from the original anti-disproportionation side line circulation point for conventional component separation.

[0041] The anti-disproportionation reaction distillation modification device for polysilicon production provided in this embodiment transfers the reaction process to the anti-disproportionation fixed bed reactor, uses bulk catalyst in the anti-disproportionation fixed bed reactor, uses the fixed bed for anti-disproportionation reaction, uses the reaction distillation tower as a separation tower, and enters the next process after obtaining the target product. The excess reactants are circulated into the mixer to participate in the reaction. Since the catalyst in the anti-disproportionation fixed bed reactor can be updated in time according to demand, the conversion rate can be increased to 99%, thereby improving the conversion efficiency. And the anti-disproportionation reaction distillation modification device provided by the utility model does not need to replace the original reaction distillation tower device. By adding an anti-disproportionation fixed bed reactor, a mixer and a heater in front of the reaction distillation tower device, the operation mode of the reaction distillation is changed, and the anti-disproportionation catalyst to be replaced in the original reaction distillation tower does not need to be cleaned, avoiding the risk of personnel operation caused by cleaning the catalyst from the anti-disproportionation distillation tower in conventional operation. After only one-time investment in the equipment, long-term operation can be guaranteed, which increases safety and operability.

[0042] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A device for transforming anti-disproportionation reaction and distillation in polysilicon production, characterized in that: It includes a mixer, a heater, an anti-disproportionation fixed bed reactor and a reactive distillation tower, wherein: The mixer can receive liquid dichlorosilane and liquid silicon tetrachloride, mix the liquid dichlorosilane and the liquid silicon tetrachloride to form a mixture of dichlorosilane and silicon tetrachloride, the mixer is connected to the heater, the heater can heat the mixture to a preset temperature, and transmit the heated mixture to the anti-disproportionation fixed bed reactor, the input end of the anti-disproportionation fixed bed reactor is connected to the heater, the output end of the anti-disproportionation fixed bed reactor is connected to the reaction distillation tower, the mixture undergoes an anti-disproportionation reaction in the anti-disproportionation fixed bed reactor under the action of a catalyst to generate trichlorosilane, the tower body of the reaction distillation tower is connected to the mixer, the top of the reaction distillation tower extracts trichlorosilane for distillation, the tower body of the reaction distillation tower extracts silicon tetrachloride that does not participate in the anti-disproportionation reaction in the anti-disproportionation reaction, and transmits the silicon tetrachloride that does not participate in the anti-disproportionation reaction to the mixer as a raw material for the anti-disproportionation reaction, and the bottom of the reaction distillation tower discharges impurities generated in the reaction.

2. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: The tower body of the reaction distillation tower is connected to the mixer via a pumping pipeline, and the pumping pipeline is provided with a silicon tetrachloride delivery pump, and the silicon tetrachloride delivery pump pumps the silicon tetrachloride that does not participate in the anti-disproportionation reaction to the mixer.

3. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: It also includes a temperature sensor, which can collect the real-time temperature of the heater. When the real-time temperature is collected, the heater can be controlled to perform temperature compensation according to the real-time temperature.

4. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 3, characterized in that: It also includes a micro control unit, which is connected to the heater and the temperature sensor respectively. When the micro control unit obtains the real-time temperature collected by the temperature sensor, the micro control unit controls the heater to perform temperature compensation according to the real-time temperature.

5. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: The bottom of the reaction distillation tower is connected to a cold hydrogenation slag slurry flash tank, and the impurities enter the cold hydrogenation slag slurry flash tank for cold hydrogenation.

6. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: The mass ratio of the liquid dichlorosilane to the liquid silicon tetrachloride is 1:

5.

7. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: When the heated mixture is transferred to the anti-disproportionation fixed bed reactor, the reaction temperature of the anti-disproportionation fixed bed reactor is 65°C.

8. The anti-disproportionation reaction distillation transformation device for polysilicon production according to claim 1, characterized in that: When the mixture undergoes an anti-disproportionation reaction in the anti-disproportionation fixed bed reactor under the action of the catalyst, and all the materials after the reaction are transferred to the reaction distillation tower, the reaction temperature of the reaction distillation tower is 70° C. and the reaction pressure is 80 kPa.

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