An integrated multi-stage spouted fluidized bed apparatus for producing high purity granular silicon
The jet-driven fluidized bed device, designed with multi-layer reaction chambers and heat exchangers, solves the problems of silicon deposition and high energy consumption in fluidized bed reactors, achieving efficient and uniform granular silicon production, increasing production capacity and reducing energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG QUHUA FLUOR CHEM CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-06-19
AI Technical Summary
When producing granular silicon, fluidized bed reactors can cause silicon to deposit on the reactor walls, reducing heat transfer efficiency. Heat in the upper part of the reactor cannot be effectively utilized, leading to increased energy consumption. Furthermore, it is difficult to control production capacity and product shape. These problems become more pronounced after expanding production capacity.
Design a multi-stage reaction chamber fluidized bed device, combining a heat exchanger and a gas distributor, to achieve the stepwise deposition of granular silicon by controlling the intake of raw material gas and setting an auxiliary gas inlet, and using the heat of the non-deposition zone to heat the auxiliary gas to avoid silicon deposition, thereby improving production capacity and product uniformity.
This achieves uniformity in the size of granular silicon, reduces energy consumption, avoids silicon deposition, increases production capacity, reduces equipment investment, and improves production efficiency and economic benefits.
Smart Images
Figure CN224371407U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of high-purity granular silicon production technology, specifically to an integrated multi-stage jet fluidized bed device for producing high-purity granular silicon. Background Technology
[0002] Granular silicon, a core raw material for semiconductors and photovoltaic devices, is currently produced using common technologies including the modified Siemens process, metallurgical methods, and fluidized bed processes. Among these, the modified Siemens process, due to its mature technology, is the dominant method globally for producing granular silicon. Its core process involves the chemical vapor deposition reaction of trichlorosilane and hydrogen on the surface of a silicon core at high temperatures, gradually generating rod-shaped silicon. However, this process requires periodic furnace shutdowns to harvest the silicon rods. This intermittent operation leads to frequent reactor start-ups and shutdowns, resulting in wasted thermal energy and limited production capacity. Furthermore, unreacted byproducts such as chlorosilanes and hydrogen chloride in the exhaust gas require complex recovery systems, further increasing energy consumption and costs.
[0003] Compared to the Siemens process, the fluidized bed process exhibits significant technological advantages. For example, it employs a continuous production mode, using fluidization technology to continuously deposit silicon-containing gases (such as silanes and chlorosilanes) on the surface of suspended seed crystal particles. This allows for the online growth and collection of particulate silicon without interrupting the reaction, effectively avoiding the heat loss problems of intermittent operation and improving unit capacity efficiency. Furthermore, the fluidized bed reactor enables highly efficient silicon deposition, and combined with the efficient heat transfer characteristics of the gas-solid two-phase system, it significantly reduces energy consumption.
[0004] Patent CN201390803Y employs a sieveless reactor, designing the carrier gas inlet to reduce the static and semi-static zones of powdered silicon, preventing sieve plate clogging, and simultaneously controlling the reaction section and reaction gas outlet temperature to address silicon deposition issues at the reaction gas nozzles. However, during the pyrolysis of silane gas within the reactor, the generated silicon easily deposits on the reactor's inner wall. This hinders heat transfer, making it difficult for silane to reach its pyrolysis temperature, reducing reaction efficiency, decreasing effective deposition on seed crystals, and consequently impacting production efficiency. After scaling up the fluidized bed reactor, silicon deposition intensifies, leading to production shutdowns for maintenance due to silicon deposition on the inner wall, severely affecting normal production.
[0005] Patent CN222358466U features an auxiliary gas inlet at the bottom periphery of the reactor body, forming an air curtain to isolate the raw material gas and seed crystals from the reactor wall, preventing silicon deposition. It also rationally designs the positions of the raw material gas inlet and the particulate silicon outlet to prevent particulate silicon from clogging the raw material gas inlet. However, this design results in high energy consumption, and the excess heat cannot be effectively utilized. Energy saving is also a key concern in these patents.
[0006] In summary, fluidized bed reactors often encounter the following problems during operation: silicon deposition on the reactor walls reduces heat transfer efficiency, hinders heat transfer, and results in insufficient reaction heat; heat in the non-deposition zone at the top of the reactor cannot be effectively utilized, increasing energy consumption and exacerbating the economic burden of production; and the size and shape of the product are also difficult to control. Especially after capacity expansion, silicon deposition, heat utilization, and control of granular silicon size and shape become mutually restrictive and difficult to achieve simultaneously, severely limiting production efficiency and economic benefits, which is a problem that urgently needs to be solved. Utility Model Content
[0007] This invention provides an integrated multi-stage spray fluidized bed device for producing high-purity granular silicon. By setting up multi-stage reaction chambers in the reactor and controlling the intake of raw material gas (silicon source gas), the granular silicon can be deposited step by step to achieve uniform size.
[0008] The specific technical solution is as follows:
[0009] An integrated multi-stage spouted fluidized bed device for producing high-purity granular silicon includes a reactor with two or more (e.g., three) reaction chambers arranged longitudinally inside the reactor. Gas distributors are arranged between adjacent reaction chambers, and a gas distributor is also arranged below the bottom reaction chamber. Each gas distributor is connected to a discharge pipe and a silicon source gas feed branch pipe. The discharge pipe connected to the bottom gas distributor is used to discharge the granular silicon product from the reactor. The discharge pipes connected to the other gas distributors are used to discharge the granular silicon product to the reaction chamber below. Each silicon source gas feed branch pipe is equipped with a regulating valve for controlling the silicon source gas flow rate.
[0010] A seed inlet is provided on the side of the reactor corresponding to the uppermost reaction chamber.
[0011] The reactor is located below the gas distributor at the bottom, where the gas inlet and auxiliary carrier gas inlet are located.
[0012] Preferably, the reactor is located above the uppermost reaction chamber with an exhaust gas outlet.
[0013] Preferably, a heat exchanger is installed above the uppermost reaction chamber of the reactor. The heat exchanger has a flow channel and is connected to a cold gas inlet pipe and a gas outlet pipe. The gas outlet pipe is connected to an auxiliary carrier gas inlet.
[0014] The reactor is equipped with an auxiliary gas inlet, which is used at least for ventilation to blow the fine powder that has passed through the heat exchanger upward back to the reaction chamber.
[0015] The heat exchanger is connected to a cold gas inlet pipe to introduce cold auxiliary gas into the heat exchanger to absorb heat from the non-deposition zone. The gas then converges with the auxiliary carrier gas inlet through the gas outlet pipe and enters the reactor. The heat exchanger and its related structural design effectively utilize the temperature of the non-deposition zone to heat the auxiliary carrier gas, reducing silicon deposition and energy waste, and achieving efficient and continuous production of high-purity granular silicon with uniform morphology and size. The heat exchanger, in conjunction with the auxiliary gas inlet, effectively gathers fine silicon powder and other microparticles in the reactor to the deposition zone for reuse, increasing production capacity while avoiding silicon deposition. The auxiliary gas inlet can be located above the heat exchanger. Preferably, for better backflushing of microparticles, the auxiliary gas inlet extends through a pipeline above the heat exchanger's flow channel. Further, the pipeline can be divided into multiple branches, each corresponding to a flow channel of the heat exchanger. More preferably, each branch is equipped with a gas flow regulating valve to control the airflow of the corresponding branch; when no airflow is needed, the airflow is zero. In some preferred embodiments, the heat exchanger is connected to the gas outlet pipe via a heat exchange outlet pipe.
[0016] Preferably, the cross-sectional diameter of the heat exchanger's flow channel is between 1 and 100 cm. When the cross-sectional diameter of the flow channel is less than 1 cm, the resistance to gas flow within the flow channel increases, potentially leading to localized blockages and affecting the uniformity of gas distribution within the reactor. Conversely, when the cross-sectional diameter of the flow channel is greater than 100 cm, the gas flow state within the flow channel is difficult to control precisely, easily resulting in uneven gas distribution, making the reaction process unstable and affecting the quality of high-purity granular silicon. Preferably, the channel length of the heat exchanger's flow channel is between 1 and 50 cm, aiming to ensure sufficient heat exchange of gas or material within the flow channel while guaranteeing efficient material transport. By controlling the cross-sectional diameter and channel length of the flow channel within the above ranges, smooth flow of gas and material within the reactor can be ensured, providing favorable conditions for the production of high-purity granular silicon.
[0017] Preferably, the flow channel of the heat exchanger is an inclined hole and / or a straight channel with a downward convergence tendency at the lower end, tilted at a 10-60 degree angle relative to the vertical direction. When using an inclined hole at a 10-60 degree angle, the gas will generate a certain tangential velocity as it passes through the inclined hole, causing the gas to rotate during the flow guidance process, further enhancing the uniform distribution of the gas. If the tilt angle is less than 10 degrees, the tangential velocity is too small, and the mixing effect is not obvious. In practical applications, the appropriate flow channel form can be selected according to the specific structure and process requirements of the reactor to achieve the best flow guidance effect.
[0018] During reactor operation, the heat exchanger must withstand harsh conditions such as high temperature, high pressure, high-speed airflow, and scouring and corrosion from the reactants. Preferably, the heat exchanger is made of one or more combinations of metal silicides, tungsten, tungsten alloys, niobium, niobium alloys, tantalum, and tantalum alloys.
[0019] Preferably, the height of each reaction chamber is 5–15 m. When the reaction chamber height is less than 5 m, the reactants cannot complete the full reaction and deposition within the chamber, resulting in a reduced yield of high-purity granular silicon. Conversely, when the reaction chamber height is greater than 15 m, it increases the overall height and volume of the reactor, increasing manufacturing costs and potentially leading to uneven distribution of parameters such as temperature and pressure within the chamber, affecting the stability and controllability of the reaction. Controlling the reaction chamber height within the range of 5–15 m ensures sufficient reaction while maintaining equipment economy, reaction stability, and energy efficiency.
[0020] The installation of a gas distributor plays a crucial role in ensuring the uniform distribution of gas within the reaction chamber and the normal progress of the reaction.
[0021] Preferably, the discharge pipe is connected to the center of the cross-section of the corresponding gas distributor.
[0022] Preferably, all discharge pipes are located on the same vertical line. This arrangement helps ensure smooth flow of reactants between adjacent reaction chambers. When the discharge pipes are aligned vertically, the reactants can fall naturally under gravity, reducing resistance and the risk of blockage during discharge. A consistent vertical discharge pipe arrangement ensures a more stable flow and distribution of reactants as they enter the next reaction chamber, which is beneficial for maintaining the stability and uniformity of the reaction within the chamber.
[0023] Preferably, for any gas distributor, two or more nozzles are evenly distributed around the center of its cross-section. These nozzles are connected to corresponding silicon source gas feed branches, enabling large-scale production of granular silicon and effectively reducing equipment investment. The use of two or more nozzles in each reaction chamber ensures a more uniform distribution of the raw material gas within the chamber, improving reaction efficiency. Multiple nozzles allow for the injection of raw material gas into the reaction chamber from different locations, effectively increasing production capacity.
[0024] In the production process of high-purity granular silicon, the nozzle needs to withstand the scouring and abrasion of the high-speed flowing raw material gas, and may also be subjected to the high temperature and corrosion generated during the reaction. Preferably, the nozzle surface is coated with a high-hardness coating, and the high-hardness coating is made of one or more combinations of silicon carbide, silicon nitride, boron nitride, and titanium nitride.
[0025] Preferably, heating devices are provided on the sides of each reaction chamber corresponding to its middle section. The heating devices are placed in the middle section of each reaction chamber because this location is typically the area where the reaction is most vigorous and requires a large amount of heat input. In the middle section of the reaction chamber, the concentration and reactivity of the reactants are high, requiring sufficient heat to sustain the reaction. The heating devices may include one or more combinations of resistance heaters, induction heaters, and microwave heaters. The heating devices can be located inside and / or outside the reactor. When the heating device is located inside the reactor, it can directly heat the reactants, reducing heat loss during heat transfer and improving heating efficiency. Placing the heating device outside the reactor offers advantages in terms of ease of installation, maintenance, and replacement. External heating devices avoid direct contact with the reactants, reducing the risk of contamination, and also facilitate monitoring and adjustment of the heating device. In practical applications, the appropriate location for the heating device needs to be selected based on a comprehensive consideration of the specific structure of the reactor, the properties of the reactants, and the requirements of the production process.
[0026] Compared with the prior art, the advantages of this utility model are as follows:
[0027] 1. The multi-layer reaction chamber design enables the gradual deposition of silicon seed crystals, resulting in uniform product size. By setting up multiple reaction chambers in the reactor and controlling the intake of raw material gas, the stepwise deposition of granular silicon can be achieved, resulting in uniform size.
[0028] 2. Low energy consumption: Through the design of the heat exchanger, the heat in the non-deposition zone of the reactor is effectively utilized to heat the auxiliary carrier gas, reducing energy waste.
[0029] 3. Effectively avoids silicon deposition. By installing a heat exchanger inside the reactor, fine silicon powder and other micro-powders can be effectively collected in the deposition zone of the reactor for reuse, increasing production capacity while avoiding silicon deposition.
[0030] 4. High production capacity and low investment: By setting two or more nozzles in the reactor, large-scale production of granular silicon can be achieved, effectively reducing equipment investment. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of an integrated multi-stage jet fluidized bed device for producing high-purity granular silicon in a specific embodiment.
[0032] Figure 2 This is a top view of the heat exchanger, cold gas inlet pipe, and heat exchange outlet pipe of the integrated multi-stage jet fluidized bed device for producing high-purity granular silicon in a specific embodiment.
[0033] Figure 3This is a schematic diagram of the heat exchanger, cold gas inlet pipe, and heat exchange outlet pipe of the integrated multi-stage jet fluidized bed device for producing high-purity granular silicon in a specific embodiment.
[0034] Figure 4 This is a top view of the gas distributor in an integrated multi-stage jet fluidized bed device for producing high-purity granular silicon, as described in a specific embodiment. Detailed Implementation
[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.
[0036] See Figures 1 to 4An integrated multi-stage fluidized bed reactor for producing high-purity granular silicon includes a reactor 1 with three longitudinally arranged reaction chambers, each with a height of 5-15 m. Heating devices 15 are installed on the sides of each reaction chamber corresponding to its middle section. The heating devices 15 include one or more combinations of resistance heaters, induction heaters, and microwave heaters. The heating devices 15 are located inside the reactor 1. Gas distributors 8 are installed between adjacent reaction chambers, and another gas distributor 8 is installed below the lowest reaction chamber. Each gas distributor 8 is connected to a discharge pipe 9. The discharge pipe 9 connected to the lowest gas distributor 8 also serves as a material discharge pipe 10, used at least to discharge the granular silicon product from the reactor 1. The discharge pipes 9 connected to the remaining gas distributors 8 are used at least to discharge the granular silicon product to the reaction chamber below. The discharge pipes 9 are connected to the center of the cross-section of the corresponding gas distributor 8, and all discharge pipes 9 are located on the same vertical line. For any gas distributor 8, two nozzles 7 are evenly distributed around the center of its cross-section. The surface of each nozzle 7 is coated with a high-hardness coating, the material of which is one or a combination of silicon carbide, silicon nitride, boron nitride, and titanium nitride. Each of the two nozzles 7 on each gas distributor 8 is connected to a silicon source gas feed branch pipe. Each silicon source gas feed branch pipe is equipped with at least one regulating valve 14 for controlling the silicon source gas flow rate, and each silicon source gas feed branch pipe is connected to the silicon source gas feed main pipe 13. A seed inlet 4 is provided on the side of the reactor 1 corresponding to the uppermost reaction chamber. Below the lowermost gas distributor 8, the reactor 1 has a gas inlet 11 and an auxiliary carrier gas inlet 12. A heat exchanger 5 is installed above the uppermost reaction chamber in reactor 1. Heat exchanger 5 has a flow channel and is connected to a cold gas inlet pipe 5-1. It is also connected to a gas outlet pipe 16 via a heat exchange outlet pipe 5-2. During operation, cold gas can be introduced into the cold gas inlet pipe 5-1, and after passing through heat exchanger 5, the cold gas flows out from the heat exchange outlet pipe 5-2 and into the gas outlet pipe 16. The gas outlet pipe 16 is connected to an auxiliary carrier gas inlet 12. The cross-sectional diameter of the flow channel in heat exchanger 5 is 1–100 cm, and the channel length is 1–50 cm. The flow channel in heat exchanger 5 is an oblique orifice and / or a straight channel inclined at 10–60 degrees relative to the vertical direction with a converging tendency at the lower end. The material of heat exchanger 5 is one or more combinations of metal silicides, tungsten, tungsten alloys, niobium, niobium alloys, tantalum, and tantalum alloys. Reactor 1, located above heat exchanger 5, is equipped with an exhaust gas outlet 2, a backup exhaust gas outlet 6 (exhaust gas can be discharged through the backup exhaust gas outlet 6 if necessary), and an auxiliary gas inlet 3. The auxiliary gas inlet 3 is used at least for ventilation to blow the fine powder passing upward through heat exchanger 5 back to the reaction chamber. Furthermore, the auxiliary gas inlet 3 extends above the flow channel of heat exchanger 5 via a pipeline, and the pipeline is divided into multiple branches, each corresponding to a flow channel of heat exchanger 5. Each branch is equipped with a gas flow regulating valve to control the ventilation volume of the corresponding branch.
[0037] Here is an example of producing high-purity granular silicon using the integrated multi-stage spouted fluidized bed device described above:
[0038] Reactor 1 is preheated to 800-1200°C. Hydrogen and N2 are then introduced into the lower section of reactor 1 through gas inlet 11 and auxiliary carrier gas inlet 12, respectively. These gases are introduced into the reaction chambers of each layer through gas distributors 8. Subsequently, trichlorosilane feed gas enters the silicon source gas feed main pipe 13, then flows through the silicon source gas feed branch pipes and nozzles 7 into the reaction chambers of each layer. Next, granular silicon seeds preheated to 1000-1100°C are added to reactor 1 through seed inlet 4. At this time, the granular silicon seeds are agitated and kept suspended by the reaction gas and auxiliary carrier gas. Heating device 15 maintains the temperature of the granular silicon seeds at 1000-1100°C. At this temperature, hydrogen reduces trichlorosilane, and the generated elemental silicon continuously deposits on the granular silicon seeds. As the reaction proceeds, granular silicon particles first deposit and grow in the uppermost fluidized bed reaction chamber. Due to gravity, they fall through the uppermost discharge pipe 9 to the middle fluidized bed reaction chamber for further deposition. Then, due to gravity, they fall through the middle discharge pipe 9 to the lowermost fluidized bed reaction chamber for further deposition. Once they reach the set process size, they are discharged from the bottom material discharge pipe 10. Finally, the bottom material discharge pipe 10 is filled with inert gas to prevent oxidation of the high-temperature product. The waste gas generated during the reaction is discharged through waste gas outlet 2 (or, if necessary, through backup waste gas outlet 6). After a period of reaction, the temperature in the non-deposition zone of reactor 1 rises. At this time, N2 enters the heat exchanger 5 through the cold gas inlet pipe 5-1 to absorb heat from the non-deposition zone. It then enters the auxiliary carrier gas inlet 12 through the heat exchange outlet pipe 5-2 and the gas outlet pipe 16, finally entering reactor 1, achieving the purpose of heat recovery and utilization.
[0039] Furthermore, it should be understood that after reading the above description of this utility model, those skilled in the art can make various alterations or modifications to this utility model, and these equivalent forms also fall within the scope defined by the appended claims.
Claims
1. An integrated multi-stage spouted fluidized bed device for producing high-purity granular silicon, characterized in that, The reactor includes a reactor with two or more reaction chambers arranged longitudinally inside. Gas distributors are installed between adjacent reaction chambers, and a gas distributor is also installed below the bottom reaction chamber. Each gas distributor is connected to a discharge pipe and a silicon source gas inlet branch pipe. The discharge pipe connected to the bottom gas distributor is used to discharge granular silicon finished product from the reactor. The discharge pipes connected to the other gas distributors are used to discharge granular silicon product to the reaction chamber below. Each silicon source gas inlet branch pipe is equipped with a regulating valve for controlling the silicon source gas flow rate. A seed inlet is provided on the side of the reactor corresponding to the uppermost reaction chamber. The reactor is located below the gas distributor at the bottom, where the gas inlet and auxiliary carrier gas inlet are located.
2. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, The reactor has an exhaust gas outlet located above the uppermost reaction chamber.
3. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, A heat exchanger is installed above the uppermost reaction chamber of the reactor. The heat exchanger has a flow channel and is connected to a cold gas inlet pipe and a gas outlet pipe. The gas outlet pipe is connected to an auxiliary carrier gas inlet. The reactor is equipped with an auxiliary gas inlet, which is used at least for ventilation to blow the fine powder that has passed through the heat exchanger upward back to the reaction chamber.
4. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The auxiliary gas inlet is located above the heat exchanger.
5. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The auxiliary gas inlet extends through a pipeline to the top of the heat exchanger's flow channel.
6. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 5, characterized in that, The pipeline is divided into multiple branches, each of which corresponds one-to-one with the flow channel of the heat exchanger.
7. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 6, characterized in that, Each branch is equipped with a gas flow regulating valve, which is used to control the ventilation volume of the corresponding branch.
8. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The heat exchanger is connected to the gas outlet pipe via the heat exchange outlet pipe.
9. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The cross-sectional diameter of the heat exchanger's flow channel is between 1 and 100 cm.
10. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The length of the flow channel in the heat exchanger ranges from 1 to 50 cm.
11. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The heat exchanger's flow channel is an inclined hole and / or a straight channel that is inclined at 10 to 60 degrees relative to the vertical direction and tends to converge at the lower end.
12. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 3, characterized in that, The heat exchanger is made of one or more of the following materials: metal silicide, tungsten, tungsten alloy, niobium, niobium alloy, tantalum, and tantalum alloy.
13. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, The height of each reaction chamber is 5-15 m.
14. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, The discharge pipe is connected to the center of the cross-section of the corresponding gas distributor.
15. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, All discharge pipes are located on the same vertical line.
16. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, For any gas distributor, two or more nozzles are evenly distributed around the center of the gas distributor's cross-section, and the nozzles are connected to the corresponding silicon source gas feed branch pipes.
17. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 16, characterized in that, The nozzle surface is coated with a high-hardness coating, the high-hardness coating being made of one or more combinations of silicon carbide, silicon nitride, boron nitride, and titanium nitride.
18. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 1, characterized in that, Heating devices are provided on the sides of each reaction chamber corresponding to the middle section of the reactor.
19. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 18, characterized in that, The heating device includes one or more combinations of resistance heaters, induction heaters, and microwave heaters.
20. The integrated multi-stage spouted fluidized bed apparatus for producing high-purity granular silicon according to claim 18, characterized in that, The heating device is located inside and / or outside the reactor.