Ultraviolet cracking reaction kettle and device system for byproduct chlorosilane high-boiling residue in polycrystalline silicon production

Abstract

The utility model provides an ultraviolet light cracking reaction kettle and a device system for a byproduct chlorosilane high-boiling residue in polycrystalline silicon production. The ultraviolet light cracking reaction kettle comprises a kettle body and components in the kettle, the kettle internal component comprises a stirring device, an ultraviolet light source assembly and a hydrogen chloride gas distributor which are arranged in the kettle body; the axial directions of the stirring device and the ultraviolet light source assembly are parallel to the axial direction of the kettle body; the hydrogen chloride gas distributor comprises a gas inlet pipe; one end of the gas inlet pipe is arranged outside the kettle body, and the other end of the gas inlet pipe is arranged in the kettle body and communicated with the annular gas distribution pipe; at least one gas distribution hole is formed in the bottom of the annular gas distribution pipe in the circumferential direction in an obliquely downward manner. The ultraviolet light cracking reaction kettle provided by the utility model adopts ultraviolet light to crack chlorosilane high-boiling residue liquid, the reaction condition is mild, the process flow is simple, solid particulate matters are prevented from being accumulated and coked, and the ultraviolet light cracking reaction kettle can stably run for a long time.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical industry, in particular to an ultraviolet light cracking reactor and a device system for producing high-boiling chlorosilane as a by-product in polysilicon production. Background Art

[0002] Currently, the modified Siemens process is the mainstream process for polysilicon production worldwide. However, a small amount of high-boiling products are produced during the production of chlorosilane and polysilicon. These high-boiling products mainly include metal chlorides, solid particles and chlorosilane oligomers. The general formula of chlorosilane oligomers is Si n Cl 2n+2-m H m (n≥2, m≤2n+2, n, m∈N). In the Siemens polysilicon production process, these by-products have no direct use value. If not properly utilized, they will not only waste resources but also cause serious environmental problems.

[0003] For example, CN105347349A discloses a process for preparing chloromonosilane by gas-phase catalytic conversion of chlorodisilane. However, this process has high energy consumption, long reaction time, and can cause solid particles in high-boiling substances to accumulate and coke on the inner wall of the reactor.

[0004] Currently, the industry generally uses organic amines as catalysts to convert high-boiling products into monosilicon compounds through cracking reactions, thereby achieving resource recovery. However, because high-boiling chlorosilane products contain metal chlorides such as aluminum trichloride, they tend to crystallize and encapsulate silicon powder when the temperature drops, gradually forming scale and causing pipeline blockage. In addition, heavy metal impurities easily complex with the catalyst functional groups within the cracking reactor, leading to catalyst poisoning.

[0005] To address these issues, CN108658082A provides a process for cracking high-boiling products in polysilicon production, cracking chlorosilane oligomers in the presence of a catalyst to produce a chlorosilane mixture. CN113149017A provides a complexing agent for removing aluminum from high-boiling products in polysilicon and its application method, removing aluminum while maintaining catalyst activity. CN115849384A provides a cracking treatment method for high-boiling products in polysilicon, using distillation to efficiently remove aluminum chloride, an impurity that can easily degrade the organic amine catalyst. However, these methods are lengthy, energy-intensive, and ineffective, making it difficult to effectively avoid poisoning the organic amine catalyst.

[0006] Therefore, how to break through the technical limitations of the existing gas-phase catalytic method and organic amine catalyst liquid-phase cracking method for treating high-boiling chlorosilanes and develop a high-boiling chlorosilane treatment device and system with a simple process, low energy consumption, and long-term stable operation is a technical problem that needs to be solved in this field. Utility Model Content

[0007] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an ultraviolet light cracking reactor and device system for producing high-boiling chlorosilane by-products in polysilicon production. The utility model uses ultraviolet light to crack the high-boiling chlorosilane liquid. Compared with the gas-phase catalytic cracking method, it can effectively reduce the energy consumption of the system and avoid the problems of solid particulate accumulation and coking. Compared with the organic amine catalytic method, it can avoid the problem of catalyst poisoning, shorten the process flow, and can operate stably for a long time.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In a first aspect, the utility model provides an ultraviolet light cracking reactor for producing high-boiling chlorosilane as a by-product in polysilicon production, the ultraviolet light cracking reactor comprising a reactor body and reactor internal components;

[0010] The internal components of the kettle include a stirring device, an ultraviolet light source assembly and a hydrogen chloride gas distributor arranged in the kettle body;

[0011] The axial directions of the stirring device and the ultraviolet light source assembly are parallel to the axial direction of the kettle body;

[0012] The hydrogen chloride gas distributor includes an air inlet pipe;

[0013] One end of the air inlet pipe is arranged outside the kettle body, and the other end is arranged inside the kettle body and communicated with the annular air distribution pipe;

[0014] The bottom of the annular air distribution pipe is provided with at least one air distribution hole obliquely downward in the circumferential direction.

[0015] Based on the above technical solution, the utility model provides an ultraviolet light source assembly and a hydrogen chloride gas distributor, so that ultraviolet light can be used as an initiator for the cracking reaction of high-boiling chlorosilanes, thereby initiating a cracking chain reaction. The high-boiling liquid is cracked by ultraviolet light under mild reaction conditions. Compared with gas-phase catalytic cracking, the system energy consumption can be reduced, the accumulation and coking of solid particles can be avoided, and the use of organic amine catalysts can be avoided, thereby avoiding the problem of catalyst poisoning. The annular gas distribution pipe and the stirring device of the hydrogen chloride gas distributor are provided, which facilitates the shearing and crushing of the gas by the stirring device, so that the hydrogen chloride gas is dispersed in the liquid, thereby improving the mass transfer coefficient between the gas and the liquid, and also facilitating the improvement of the heat transfer coefficient between the reactants and the jacket, thereby ensuring the timely and rapid removal of the cracking heat.

[0016] As a preferred technical solution of the present invention, the kettle body includes a kettle body side wall, an upper head and a lower head;

[0017] The top of the side wall of the kettle body is connected to the upper head, and the bottom of the side wall of the kettle body is connected to the lower head;

[0018] A jacket is provided on the outer side of the side wall of the kettle body and the lower head;

[0019] The side wall of the kettle body is provided with a high-boiling liquid inlet, and the high-boiling liquid inlet is provided through the jacket;

[0020] The bottom of the lower head is provided with a liquid outlet, and the liquid outlet is provided through the jacket;

[0021] The upper head is provided with a gas outlet;

[0022] The gas inlet pipe of the hydrogen chloride gas distributor passes through the lower head and the jacket and is located on one side of the bottom of the lower head.

[0023] Based on the above technical solution, the present invention enhances heat transfer efficiency by providing a jacket, allowing cooling or heating media to flow through the jacket, thereby controlling the temperature within the reactor. Furthermore, a gas outlet is provided in the upper head to facilitate the discharge of unreacted hydrogen chloride gas.

[0024] As a preferred technical solution of the present invention, the stirring device includes a stirring paddle, a stirring shaft and a motor;

[0025] The motor is arranged outside the kettle body and above the upper head;

[0026] The output end of the motor is connected to the top of the stirring shaft, and the other end of the stirring shaft is arranged in the kettle body and connected to the stirring paddle.

[0027] Based on the above technical solution, the present invention incorporates a stirring device that facilitates the dispersion of hydrogen chloride gas in the liquid, improving the mass transfer coefficient between the gas and the liquid. It also facilitates the heat transfer coefficient between the reactants and the jacket, ensuring the timely and rapid removal of the heat of cracking. The sealing and drive methods of the stirring device in the present invention can employ conventional methods in the art, such as packing seals and gear drives.

[0028] As a preferred technical solution of the present invention, the number of stirring devices in the kettle body is at least 1, for example, it can be 1, 2 or 3, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable; the stirring paddle includes at least 1 layer, for example, it can be 1 layer, 2 layers or 3 layers, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0029] Based on the above technical solution, the stirring device in the present invention can be provided singly or in combination, which can promote uniform mixing of gas and liquid in the reactor and improve the reaction effect. In the present invention, the form of the stirring paddle is not particularly limited, and for example, it can be any of a disc turbine type, an open turbine type, or a propeller type.

[0030] As a preferred technical solution of the present invention, the ultraviolet light source assembly includes an ultraviolet linear lamp and a quartz sleeve arranged on the outside of the ultraviolet linear lamp, a cooling water channel is provided in the quartz sleeve, and a cooling water inlet and a cooling water outlet are provided on the upper part of the quartz sleeve, and the cooling water inlet and the cooling water outlet are respectively connected to the cooling water channel.

[0031] Based on the above technical solution, the present invention utilizes a quartz sleeve to protect the UV linear lamp. The upper portion of the quartz sleeve is provided with a cooling water inlet and outlet. The cooling water reduces the temperature of the UV linear lamp, thereby extending the lamp's service life. In the present invention, the top of the UV linear lamp is typically connected to an actinic control device, a programmable logic controller (PLC) that controls the wavelength and intensity of the UV light source.

[0032] As a preferred technical solution of the present invention, the number of ultraviolet light source components in the kettle body is at least 1, for example, it can be 1, 2 or 3, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0033] Based on the above technical solution, the present invention can further ensure that there is no ultraviolet light irradiation dead zone in the reactor by providing at least one ultraviolet light source assembly.

[0034] As a preferred technical solution of the present invention, the surface roughness Ra of the inner wall of the kettle body and the surface roughness Ra of the components inside the kettle are each independently less than 0.25μm, for example, they can be 0.24μm, 0.23μm, 0.22μm, 0.21μm, 0.2μm, 0.19μm, 0.18μm, 0.16μm or 0.15μm, but are not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0035] Based on the above technical solution, the present invention controls the surface roughness of the internal components and the inner wall of the kettle to be less than 0.25 μm, and further preferably less than 0.2 μm, which is beneficial to reducing the diffuse reflection of ultraviolet light and enhancing the intensity of ultraviolet light.

[0036] As a preferred technical solution of the present invention, the air distribution holes are arranged at equal intervals on the annular air distribution pipe.

[0037] Based on the above technical solution, the utility model can further promote uniform mixing of gas and liquid by arranging the air distribution holes at equal intervals on the annular air distribution pipe.

[0038] In a second aspect, the present invention provides an ultraviolet cracking device system for producing high-boiling-point chlorosilane as a by-product of polysilicon production, the ultraviolet cracking device system comprising the ultraviolet cracking reactor for producing high-boiling-point chlorosilane as a by-product of polysilicon production as described in the first aspect of the present invention.

[0039] Based on the above technical solution, in the utility model, ultraviolet light is used as an initiator for the cracking reaction of high-boiling chlorosilanes, thereby initiating a cracking chain reaction. Ultraviolet light is used to crack the high-boiling liquid, and the reaction conditions are mild. Compared with gas-phase catalytic cracking, it can reduce system energy consumption, avoid the accumulation and coking of solid particles, and avoid the use of organic amine catalysts, which can avoid the problem of catalyst poisoning.

[0040] As a preferred technical solution of the present utility model, the ultraviolet cracking device system further includes a filtering device, a heat exchange device, a distillation tower, a first condensing device and a second condensing device;

[0041] Along the flow direction of the high-boiling chlorosilane product, the liquid phase outlet of the filtering device, the cold source inlet of the heat exchange device, the cold source outlet of the heat exchange device and the high-boiling liquid inlet of the ultraviolet cracking reactor are connected in sequence, the liquid outlet of the ultraviolet cracking reactor is connected to the feed inlet of the distillation tower, the bottom material outlet of the distillation tower is connected to the first condensing device, the condensed material outlet of the first condensing device is respectively connected to the bottom material reflux port and the bottom material output pipeline of the distillation tower, the top material outlet of the distillation tower is connected to the second condensing device, and the condensed material outlet of the second condensing device is respectively connected to the top material reflux port and the top material output pipeline of the distillation tower.

[0042] Based on the above technical solution, the device system provided by the utility model removes solid impurities such as silicon powder contained in high-boiling chlorosilane products through a filtration device, thereby reducing the attenuation of ultraviolet light by solid particles; the high-boiling products are heated by a heat exchange device and then passed into an ultraviolet cracking reactor for reaction. The reacted materials flow to a distillation tower and are cooled by a first condensing device and a second condensing device, respectively. A portion of the condensed materials is refluxed and a portion is output, resulting in monosilicon chlorosilane and non-condensable gas at the top of the tower. In the filtration device provided by the utility model, pressure gauges can also be installed before and after the filtration device to monitor the pressure difference before and after filtration, facilitating timely clearing of blockages in the filtration device.

[0043] In the present invention, the filtering device, heat exchange device and condensing device can all be conventional devices in the field. The filtering device can be, for example, a filter, the heat exchange device can be, for example, a heat exchanger, and the first condensing device and the second condensing device can be, for example, a condenser.

[0044] The operation process of the ultraviolet cracking reactor and ultraviolet cracking device system provided by the utility model for cracking high-boiling chlorosilanes is as follows:

[0045] The collected mixed liquid containing high-boiling chlorosilane products is sent to a filtration device for filtration to remove solid impurities such as silicon powder contained in the mixed liquid and reduce the attenuation of ultraviolet light by solid particles. The mixed liquid containing high-boiling chlorosilane products is a silicon tetrachloride mixed liquid collected from the distillation section and containing high-boiling products such as Si2Cl6, Si2HCl5, Si2H2Cl4, and the mass percentage of the high-boiling products is 2-10%;

[0046] Then, the filtered mixed liquid is sent to the heat exchange device and heated to 80-100°C;

[0047] Next, the heated mixed liquid is fed into the ultraviolet cracking reactor through the high-boiling liquid inlet, the stirring device is turned on, hydrogen chloride gas is introduced through the gas distribution holes of the annular gas distribution pipe of the hydrogen chloride gas distributor, the ultraviolet light source assembly is turned on to irradiate the reactor with ultraviolet light, and a quartz sleeve is used to cool the ultraviolet linear lamp. The ultraviolet light uses UVA with a wavelength of 340-400nm. After the reaction is carried out at 80-100°C and a pressure of 0.5-1MPa for 1-2 hours, the introduction of hydrogen chloride gas is stopped, the ultraviolet light source assembly is turned off, and the reaction product is allowed to flow to the distillation tower through the liquid outlet;

[0048] Afterwards, distillation separation is carried out in a distillation tower, the top product enters the second condensing device, and the product in the bottom of the tower enters the first condensing device, and then refluxes and outputs respectively, and monochlorosilane and non-condensable gas are obtained at the top of the tower.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] (1) The ultraviolet light cracking reactor provided by the utility model utilizes ultraviolet light as an initiator for the cracking reaction of high-boiling chlorosilanes, thereby initiating a cracking chain reaction. The reaction conditions are mild. Compared with gas-phase catalytic cracking, it can reduce system energy consumption, avoid accumulation of solid particles and coking, and ensure stable operation of the equipment. At the same time, it avoids the use of organic amine catalysts, can avoid the problem of catalyst poisoning, shorten the process flow, reduce the reaction temperature and energy consumption, and can make the cracking rate of high-boiling chlorosilanes reach more than 95%, and the yield of monochlorosilane reach more than 90%.

[0051] (2) The ultraviolet light cracking reactor provided by the present invention is provided with a stirring device and an annular gas distribution pipe, and the annular gas distribution pipe is provided with gas distribution holes. The stirring device can be used to shear and crush the gas, which is beneficial to the dispersion of hydrogen chloride gas in the liquid and improves the mass transfer coefficient between the gas and the liquid. At the same time, it is beneficial to improve the heat transfer coefficient between the reactor and the jacket, ensuring the timely and rapid removal of the cracking heat.

[0052] (3) The ultraviolet light cracking reactor provided by the utility model can reduce the diffuse reflection of ultraviolet light and enhance the intensity of ultraviolet light by controlling the surface roughness of the inner wall of the reactor and the internal components of the reactor, thereby further improving the cracking effect of high-boiling substances.

[0053] (4) The ultraviolet cracking device system provided by the utility model is equipped with a filtering device, a heat exchange device, an ultraviolet cracking reactor, a distillation tower, a first condensing device and a second condensing device. It can first filter the high-boiling chlorosilanes and intercept the particulate matter such as silicon powder contained therein to prevent them from entering the cracking reactor, thereby reducing the attenuation of ultraviolet light by solid particles. The device system has a simple structure and a low investment cost, which is conducive to industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic structural diagram of the ultraviolet light cracking reactor provided in Example 1 of the present utility model;

[0055] Figure 2 This is a schematic diagram of the structure of the ultraviolet light cracking device system provided in Example 1 of the present utility model;

[0056] Figure 3 A top view of the hydrogen chloride gas distributor provided in Example 1 of the present utility model;

[0057] In the figure: 1-UV light cracking reactor; 2-filtration device; 3-heat exchange device; 4-distillation tower; 5-first condensing device; 6-second condensing device;

[0058] 101-jacket; 102-high-boiling liquid inlet; 103-liquid outlet; 104-gas outlet; 105-hydrogen chloride gas distributor; 106-stirring paddle; 107-stirring shaft; 108-motor; 109-ultraviolet linear lamp; 110-quartz sleeve; 111-air inlet pipe; 112-annular air distribution pipe; 113-air distribution holes; 114-cooling water inlet; 115-cooling water outlet. DETAILED DESCRIPTION

[0059] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0060] The following is a further detailed description of the present invention. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0061] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0062] It should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0063] Those skilled in the art should understand that the present invention must include necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not constitute the main innovation of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements or specific limitations on this.

[0064] Example 1

[0065] This embodiment provides a UV-light cracking reactor for producing high-boiling chlorosilane as a by-product of polysilicon production. Figure 1 As shown, the ultraviolet light cracking reactor includes a reactor body and internal components. The internal components include a stirring device, an ultraviolet light source assembly, and a hydrogen chloride gas distributor 105 arranged in the reactor body. The surface roughness Ra of the internal components and the inner wall surface roughness Ra of the reactor body are both 0.2 μm.

[0066] The kettle body includes a kettle side wall, an upper head and a lower head. The top of the kettle side wall is connected to the upper head, and the bottom of the kettle side wall is connected to the lower head. A jacket 101 is provided on the outside of the kettle side wall and the lower head. The kettle side wall is provided with a high-boiling liquid inlet 102, and the high-boiling liquid inlet 102 is provided through the jacket 101. The bottom of the lower head is provided with a liquid outlet 103, and the liquid outlet 103 is provided through the jacket 101. The upper head is provided with a gas outlet 104. The gas inlet pipe 111 of the hydrogen chloride gas distributor 105 passes through the lower head and the jacket 101 and is located on the bottom side of the lower head.

[0067] The axial direction of the stirring device is parallel to the axial direction of the kettle body. The stirring device includes a stirring paddle 106, a stirring shaft 107 and a motor 108. The motor 108 is arranged outside the kettle body and above the upper head. The output end of the motor 108 is connected to the top of the stirring shaft 107. The other end of the stirring shaft 107 is arranged in the kettle body and connected to the stirring paddle 106. The number of stirring devices in the kettle body is one, and the stirring paddle 106 is two-layered, with a disc turbine structure.

[0068] like Figure 3 As shown, the hydrogen chloride gas distributor 105 includes an air inlet pipe 111, one end of which is arranged outside the kettle body, and the other end is arranged inside the kettle body and communicates with an annular air distribution pipe 112. The bottom of the annular air distribution pipe 112 is provided with 10 air distribution holes 113 circumferentially and obliquely downwardly. The air distribution holes 113 are evenly spaced on the annular air distribution pipe 112.

[0069] The axial direction of the ultraviolet light source assembly is parallel to the axial direction of the kettle body. The ultraviolet light source assembly includes an ultraviolet linear lamp 109 and a quartz sleeve 110 arranged on the outside of the ultraviolet linear lamp 109. A cooling water channel is provided in the quartz sleeve 110. A cooling water inlet 114 and a cooling water outlet 115 are provided on the upper part of the quartz sleeve 110. The cooling water inlet 114 and the cooling water outlet 115 are respectively connected to the cooling water channel. There are two ultraviolet light source assemblies in the kettle body to ensure that there is no ultraviolet light irradiation dead zone in the kettle.

[0070] This embodiment also provides an ultraviolet cracking device system for producing polysilicon with high-boiling chlorosilane as a by-product using the above-mentioned ultraviolet cracking reactor. Figure 2 As shown, the ultraviolet cracking device system further includes a filtering device 2, a heat exchange device 3, a distillation tower 4, a first condensing device 5 and a second condensing device 6;

[0071] Along the flow direction of the high-boiling chlorosilane product, the liquid phase outlet of the filtering device 2, the cold source inlet of the heat exchange device 3, the cold source outlet of the heat exchange device 3 and the high-boiling liquid inlet 102 of the ultraviolet cracking reactor 1 are connected in sequence, the liquid outlet 103 of the ultraviolet cracking reactor 1 is connected to the feed port of the distillation tower 4, the bottom material outlet of the distillation tower 4 is connected to the first condensing device 5, the condensed material outlet of the first condensing device 5 is respectively connected to the bottom material reflux port and the bottom material output pipeline of the distillation tower 4, the top material outlet of the distillation tower 4 is connected to the second condensing device 6, and the condensed material outlet of the second condensing device 6 is respectively connected to the top material reflux port and the top material output pipeline of the distillation tower 4.

[0072] The operation process of the UV cracking reactor and UV cracking device system provided in the above embodiment for cracking high-boiling chlorosilanes is as follows:

[0073] The collected mixed liquid containing high-boiling chlorosilane products is sent to the filter device 2 for filtration to remove solid impurities such as silicon powder contained in the mixed liquid and reduce the attenuation of ultraviolet light by solid particles. The mixed liquid containing high-boiling chlorosilane products is a silicon tetrachloride mixed liquid containing high-boiling products such as Si2Cl6, Si2HCl5, Si2H2Cl4, etc. collected from the distillation section, and the mass percentage of the high-boiling products is 5%;

[0074] Then, the filtered mixed liquid is sent to the heat exchange device 3 and heated to 90°C;

[0075] Next, the heated mixed liquid is fed into the ultraviolet cracking reactor 1 through the high-boiling liquid inlet 102. The stirring device is turned on, and hydrogen chloride gas is introduced through the gas distribution holes 113 of the annular gas distribution pipe 112 of the hydrogen chloride gas distributor 105. The ultraviolet light source assembly is turned on to irradiate the reactor with ultraviolet light. At the same time, the quartz sleeve 110 cools the ultraviolet linear lamp 109. The ultraviolet light uses UVA with a wavelength of 340-400nm. After the reaction is carried out at 90°C and a pressure of 0.6 MPa for 1.5 hours, the introduction of hydrogen chloride gas is stopped, the ultraviolet light source assembly is turned off, and the reaction product flows through the liquid outlet 103 to the distillation tower 4.

[0076] Taking Si2Cl6 as an example, the bond energy of Cl3Si-SiCl3 is 85kcal / mol, which requires 3.71eV of energy. Ultraviolet light of 340-400nm can cause the high-boiling chlorosilane to undergo a cracking reaction. The reaction process and principle in the reactor are as follows:

[0077] Si2HCl5+e - →SiClH + +SiCl4+2e - ;

[0078]

[0079] SiCl2+HCl→SiHCl3;

[0080] Afterwards, distillation separation is carried out in the distillation tower 4, the top product enters the second condensing device 6, and the product in the bottom enters the first condensing device 5, and then refluxes and outputs respectively, and monochlorosilane and non-condensable gas are obtained at the top of the tower.

[0081] The use of the ultraviolet cracking reactor and ultraviolet cracking device system provided in this embodiment can achieve a cracking rate of high-boiling chlorosilane products of more than 95%, and a yield of monochlorosilane of more than 90%.

[0082] In summary, the ultraviolet light cracking reactor and device system for producing high-boiling chlorosilane by-products in polysilicon production provided by the utility model uses ultraviolet light to crack the high-boiling chlorosilane liquid. Compared with the gas-phase catalytic cracking method, it can effectively reduce the energy consumption of the system and avoid the problems of solid particulate accumulation and coking. Compared with the organic amine catalysis method, it can avoid the problem of catalyst poisoning, shorten the process flow, and can operate stably for a long time.

[0083] The applicant declares that the above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Technicians in the relevant technical field should understand that any changes or substitutions that can be easily thought of by technicians in the relevant technical field within the technical scope disclosed in the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. An ultraviolet light cracking reactor for high-boiling chlorosilane by-products in polysilicon production, characterized in that: The ultraviolet light cracking reactor comprises a reactor body and internal components; The internal components of the kettle include a stirring device, an ultraviolet light source assembly and a hydrogen chloride gas distributor arranged in the kettle body; The axial directions of the stirring device and the ultraviolet light source assembly are parallel to the axial direction of the kettle body; The hydrogen chloride gas distributor includes an air inlet pipe; One end of the air inlet pipe is arranged outside the kettle body, and the other end is arranged inside the kettle body and communicated with the annular air distribution pipe; The bottom of the annular air distribution pipe is provided with at least one air distribution hole obliquely downward in the circumferential direction.

2. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 1, characterized in that: The kettle body includes a kettle body side wall, an upper head and a lower head; The top of the side wall of the kettle body is connected to the upper head, and the bottom of the side wall of the kettle body is connected to the lower head; A jacket is provided on the outer side of the side wall of the kettle body and the lower head; The side wall of the kettle body is provided with a high-boiling liquid inlet, and the high-boiling liquid inlet is provided through the jacket; The bottom of the lower head is provided with a liquid outlet, and the liquid outlet is provided through the jacket; The upper head is provided with a gas outlet; The gas inlet pipe of the hydrogen chloride gas distributor passes through the lower head and the jacket and is located on one side of the bottom of the lower head.

3. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 2, characterized in that: The stirring device includes a stirring paddle, a stirring shaft and a motor; The motor is arranged outside the kettle body and above the upper head; The output end of the motor is connected to the top of the stirring shaft, and the other end of the stirring shaft is arranged in the kettle body and connected to the stirring paddle.

4. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 3, characterized in that: The number of stirring devices in the kettle body is at least 1; The stirring blade includes at least one layer.

5. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 1, characterized in that: The ultraviolet light source assembly includes an ultraviolet linear lamp and a quartz sleeve arranged outside the ultraviolet linear lamp, a cooling water channel is provided in the quartz sleeve, and a cooling water inlet and a cooling water outlet are provided on the upper part of the quartz sleeve, and the cooling water inlet and the cooling water outlet are respectively connected to the cooling water channel.

6. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 1, characterized in that: The number of the ultraviolet light source assembly in the kettle body is at least one.

7. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 1, characterized in that: The surface roughness Ra of the inner wall of the kettle body and the surface roughness Ra of the components inside the kettle are each independently less than 0.25 μm.

8. The ultraviolet light cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production according to claim 1, characterized in that: The air distribution holes are arranged at equal intervals on the annular air distribution pipe.

9. An ultraviolet cracking device system for high-boiling chlorosilane by-products in polysilicon production, characterized in that: The ultraviolet cracking device system includes the ultraviolet cracking reactor for producing high-boiling chlorosilane by-products in polysilicon production as described in any one of claims 1 to 8.

10. The ultraviolet light cracking device system for high-boiling chlorosilane by-products in polysilicon production according to claim 9, characterized in that: The ultraviolet cracking device system also includes a filtering device, a heat exchange device, a distillation tower, a first condensing device and a second condensing device; Along the flow direction of the high-boiling chlorosilane product, the liquid phase outlet of the filtering device, the cold source inlet of the heat exchange device, the cold source outlet of the heat exchange device and the high-boiling liquid inlet of the ultraviolet cracking reactor are connected in sequence, the liquid outlet of the ultraviolet cracking reactor is connected to the feed inlet of the distillation tower, the bottom material outlet of the distillation tower is connected to the first condensing device, the condensed material outlet of the first condensing device is respectively connected to the bottom material reflux port and the bottom material output pipeline of the distillation tower, the top material outlet of the distillation tower is connected to the second condensing device, and the condensed material outlet of the second condensing device is respectively connected to the top material reflux port and the top material output pipeline of the distillation tower.

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