Apparatus and method for producing trichlorosilane

Abstract

The application provides a device and a method for preparing trichlorosilane, and the device comprises a trichlorosilane synthesis system, a dry dust removal system, a wet dust removal system, a heavy component removal and purification system and a slag slurry treatment system; the trichlorosilane synthesis system comprises a trichlorosilane reactor; the dry dust removal system comprises a cyclone separator; the wet dust removal system comprises a spray tower, a reboiler, a heat exchanger and a first condenser; and the heavy component removal and purification system comprises a heavy component removal tower and a carbon adsorption tower. The device combines the pneumatic conveying of silicon powder in the entire polysilicon industry, and combines the energy-saving technology of condensing mixed gas as the liquid phase of spray washing by using the heat exchanger, the energy-saving means of bidirectional extraction of trichlorosilane and tetrachlorosilane components, and the technology of slag slurry concentration and recovery, so that the effective resource integration of the entire system is achieved, the technical effects of low energy consumption and cyclic reuse are fully realized, and a high-purity trichlorosilane production system which can run independently and self-compensate is created.

Description

Technical Field

[0001] This invention relates to the field of trichlorosilane preparation technology, and specifically to an apparatus and method for preparing trichlorosilane. Background Technology

[0002] Currently, the industry commonly uses cold hydrogenation fluidized bed technology to produce trichlorosilane. This involves using hydrogen, silicon powder, and silicon tetrachloride in a fluidized bed to supplement heat and produce chlorosilanes. The chemical reaction equation for the cold hydrogenation process is as follows: 3SiCl4 + 2H2 + Si = 4SiHCl3. When using the cold hydrogenation method, trichlorosilane accounts for only about 25% of the chlorosilane.

[0003] Besides the cold hydrogenation method for producing trichlorosilane, another method involves producing chlorosilane in a fluidized bed using silicon powder and hydrogen chloride, followed by exothermic, constant-temperature production at 350°C. This method can achieve a trichlorosilane content of over 80%, significantly improving efficiency compared to cold hydrogenation. However, chlorosilanes contain impurities such as silicon powder, silicon tetrachloride, and high-boiling-point substances. The key technical challenge for this method lies in further removing these impurities to produce refined, high-purity trichlorosilane. Summary of the Invention

[0004] In view of this, the present invention provides an apparatus and method for preparing trichlorosilane, the apparatus being able to prepare high-purity trichlorosilane while achieving the goal of reducing energy consumption.

[0005] To address the technical problems mentioned in the background section, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an apparatus for preparing trichlorosilane, comprising:

[0007] Trichlorosilane synthesis system, dry dust removal system, wet dust removal system, heavy weight removal and purification system, and slurry treatment system;

[0008] The trichlorosilane synthesis system includes a trichlorosilane reactor; the dry dust removal system includes a cyclone separator; the wet dust removal system includes a scrubbing tower, a reboiler, a heat exchanger, and a first condenser. The scrubbing tower includes a tower body and a tower plate. The sidewalls of the scrubbing tower body are respectively provided with a first inlet and a second inlet. The top of the scrubbing tower body is provided with a first outlet, and the bottom of the scrubbing tower body is provided with a second outlet. The first condenser is provided with a chlorosilane inlet and a chlorosilane outlet. The heavy metal removal and purification system includes a heavy metal removal tower and a carbon adsorption tower. The sidewalls of the heavy metal removal tower are provided with a heavy metal removal tower inlet, and the opposite side of the heavy metal removal tower inlet is provided with a heavy metal removal tower side outlet. The top of the heavy metal removal tower is provided with a trichlorosilane outlet, and the bottom of the heavy metal removal tower is provided with a waste gas outlet.

[0009] The outlet at the top of the trichlorosilane reactor is connected to the inlet of the cyclone separator; the outlet of the cyclone separator is connected to the inlet of the side wall of the trichlorosilane reactor and the first inlet of the scrubbing tower; the second outlet of the scrubbing tower is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the slurry treatment system; the first outlet of the scrubbing tower is connected to the inlet of the heat exchanger, and the outlet of the heat exchanger is connected to the second inlet of the scrubbing tower; the first outlet of the scrubbing tower is also connected to the chlorosilane inlet of the first condenser; the chlorosilane outlet of the first condenser is connected to the inlet of the heavy silane removal tower; the trichlorosilane outlet of the heavy silane removal tower is connected to the inlet of the carbon adsorption tower; and the exhaust gas outlet of the heavy silane removal tower is connected to the slurry treatment system.

[0010] Furthermore, the device also includes: a silicon powder feeding system and a hydrogen chloride raw material pipeline; the silicon powder feeding system includes: a silicon powder feeding tank and a hydrogen chloride gas conveying pipeline, the outlet of the hydrogen chloride gas conveying pipeline being connected to the interior of the silicon powder feeding tank, and the outlet of the silicon powder feeding tank being connected to the interior of the trichlorosilane reactor; the outlet of the hydrogen chloride raw material pipeline being connected to the interior of the trichlorosilane reactor.

[0011] Furthermore, the silicon powder in the silicon powder feeding tank is silicon powder with a particle size of 40-325 mesh.

[0012] Furthermore, the slurry treatment system includes a thickening tower, the outlet of which is connected to the inlet of the deweighting tower.

[0013] Furthermore, the dry dust removal system also includes a primary bag filter and a secondary bag filter; the inlet of the primary bag filter is connected to the outlet of the cyclone separator, and the outlet of the primary bag filter is connected to the first inlet of the scrubbing tower and the inlet of the secondary bag filter, respectively.

[0014] Furthermore, the de-heavy purification system includes a trichlorosilane product storage tank and a tetrachlorosilane product storage tank; the outlet of the carbon adsorption tower is connected to the interior of the trichlorosilane product storage tank; and the side outlet of the de-heavy tower is connected to the interior of the tetrachlorosilane product storage tank.

[0015] Furthermore, the trichlorosilane reactor is a fluidized bed.

[0016] Furthermore, the wet dust removal system includes at least two scrubbing towers connected in series; and / or the heavy metal removal and purification system includes at least two carbon adsorption towers connected in series.

[0017] Furthermore, the device also includes a hydrogen recovery system; the first condenser is also provided with a gas outlet, which is connected to the hydrogen recovery system.

[0018] Secondly, the present invention provides a method for preparing trichlorosilane, the method utilizing the apparatus described above.

[0019] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0020] This invention provides an apparatus for preparing trichlorosilane, comprising: a trichlorosilane synthesis system, a dry dust removal system, a wet dust removal system, a heavy removal and purification system, and a slurry treatment system;

[0021] The trichlorosilane synthesis system includes a trichlorosilane reactor; the dry dust removal system includes a cyclone separator; the wet dust removal system includes a scrubbing tower, a reboiler, a heat exchanger, and a first condenser. The scrubbing tower includes a tower body and a tower plate. The sidewalls of the scrubbing tower body are respectively provided with a first inlet and a second inlet. The top of the scrubbing tower body is provided with a first outlet, and the bottom of the scrubbing tower body is provided with a second outlet. The first condenser is provided with a chlorosilane inlet and a chlorosilane outlet. The heavy metal removal and purification system includes a heavy metal removal tower and a carbon adsorption tower. The sidewalls of the heavy metal removal tower are provided with a heavy metal removal tower inlet, and the opposite side of the heavy metal removal tower inlet is provided with a heavy metal removal tower side intake. The top of the heavy metal removal tower is provided with a trichlorosilane outlet, and the bottom of the heavy metal removal tower is provided with a waste gas outlet.

[0022] This invention combines the pneumatic conveying method for silicon powder production found throughout the polysilicon industry with energy-saving technologies such as using heat exchanger condensate mixed gas as the rinsing liquid phase, bidirectional extraction of trichlorosilane and tetrachlorosilane components, and slurry concentration and recovery. This achieves effective resource integration across the entire system, fully realizing low energy consumption and recycling, creating a self-operating, self-compensating high-purity trichlorosilane production technology. This invention recovers approximately 98% of the silicon powder, overcoming the current problem of unusable silicon powder resources in the traditional trichlorosilane industry. It also solves the problems of low-quality chlorosilanes and low automation, producing not only crude chlorosilanes but also purified silicon tetrachloride and high-boiling-point compounds. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the assembly of the apparatus for preparing trichlorosilane in this invention.

[0024] Figure label:

[0025] 1. Silicon powder feeding system; 2. Trichlorosilane synthesis system; 3. Dry dust removal system; 4. Wet dust removal system; 5. Heavy dust removal and purification system; 6. Slurry treatment system; 7. Hydrogen recovery system; 8. Hydrogen chloride raw material pipeline.

[0026] 11. Silicon powder silo, 12. Silicon powder feeding tank, 13. Hydrogen chloride gas conveying pipeline, 14. Silicon powder buffer tank, 15. Silicon powder filter, 16. Nitrogen venting tank;

[0027] 21. Trichlorosilane reactor; 22. Condensate pipe; 23. Steam pipe;

[0028] Cyclone separator 31, primary bag filter 32, secondary bag filter 33, silica powder bag 34, first waste gas tank 35;

[0029] 41. Scrubber tower; 42. First condenser;

[0030] 51. De-weighting tower; 52. Carbon adsorption tower; 53. Trichlorosilane product storage tank; 54. Tetrachlorosilane product storage tank;

[0031] 61. Settling tank; 62. Dryer; 63. Condensation recovery device; 64. Concentration tower; 65. Second condenser; 66. Hydrolysis device; 67. Second waste gas tank; 68. High boiling tank.

[0032] Hydrogen chloride buffer tank 81. Detailed Implementation

[0033] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the present invention.

[0034] The following is in conjunction with the appendix Figure 1 The apparatus for preparing trichlorosilane in this invention will be further explained.

[0035] In a first aspect, the present invention provides an apparatus for preparing trichlorosilane, comprising:

[0036] The system comprises a trichlorosilane synthesis system 2, a dry dust removal system 3, a wet dust removal system 4, a heavy metal removal and purification system 5, and a slurry treatment system 6; wherein, the trichlorosilane synthesis system 2 includes a trichlorosilane reactor 21; the dry dust removal system 3 includes a cyclone separator 31; the wet dust removal system 4 includes a scrubbing tower 41, a reboiler, a heat exchanger, and a first condenser 42, the scrubbing tower 41 including a scrubbing tower body and scrubbing tower plates, and the sidewalls of the scrubbing tower body are respectively provided with a first inlet and a second inlet. The scrubbing tower has a first outlet at its top and a second outlet at its bottom. The first condenser 42 has a chlorosilane inlet and a chlorosilane outlet. The heavy removal and purification system 5 includes a heavy removal tower 51 and a carbon adsorption tower 52. The side wall of the heavy removal tower 51 has a heavy removal tower inlet, and the opposite side of the heavy removal tower inlet has a heavy removal tower side sampling port. The top of the heavy removal tower 51 has a trichlorosilane outlet, and the bottom of the heavy removal tower 51 has a waste gas outlet.

[0037] The outlet at the top of the trichlorosilane reactor 21 is connected to the inlet of the cyclone separator 31; the outlet of the cyclone separator 31 is connected to the inlet of the side wall of the trichlorosilane reactor 21 and the first inlet of the scrubbing tower 41; the second outlet of the scrubbing tower 41 is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the slurry treatment system 6; the first outlet of the scrubbing tower 41 is connected to the inlet of the heat exchanger, and the outlet of the heat exchanger is connected to the second inlet of the scrubbing tower 41; the first outlet of the scrubbing tower 41 is also connected to the chlorosilane inlet of the first condenser 42; the chlorosilane outlet of the first condenser 42 is connected to the inlet of the heavy removal tower; the trichlorosilane outlet of the heavy removal tower 51 is connected to the inlet of the carbon adsorption tower 52; and the exhaust gas outlet of the heavy removal tower 51 is connected to the slurry treatment system 6.

[0038] In the apparatus provided in this invention, each system performs the following functions:

[0039] (1) Trichlorosilane synthesis system 2: In the trichlorosilane synthesis system 2, raw material silicon powder and hydrogen chloride are boiled in the trichlorosilane reactor 21 and reacted at 350°C to generate chlorosilane. The chlorosilane exists in the form of a mixed gas, and the mixed gas contains unreacted silicon powder;

[0040] (2) Dry dust removal system 3: To remove the silicon powder mixed in, the device is equipped with a dry dust removal system 3. Specifically, the mixture of gas and silicon powder enters the cyclone separator 31 from the outlet at the top of the trichlorosilane reactor 21. The cyclone separator 31 can separate the silicon powder in the gas mixture. At the same time, large particles of silicon powder (generally 20-160 mesh) are separated into the slag container by centrifugal inertia. After separation, they return to the trichlorosilane reactor 21 to participate in the reaction. The gas mixture after being dusted by the dry dust removal system 3 then enters the downstream wet dust removal system 4.

[0041] (3) Wet dust removal system 4: In addition to trichlorosilane, the mixed gas also contains tetrachlorosilane, metal chlorides, trace amounts of fine silica powder, high boiling point, and hydrogen, among other impurities. The wet dust removal system 4 mainly removes metal chlorides and trace amounts of fine silica powder. Specifically, the mixed gas enters the scrubbing tower 41 and is dusted through a bubbling vapor-liquid exchange process. When the mixed gas passes through the liquid layer of the tower plate, the fine silica dust and metal chlorides carried in the mixed gas are washed to the bottom of the tower bottom with the liquid phase and enter the reboiler from the second outlet of the scrubbing tower 41. The reboiler sends the metal chlorides and fine silica powder to the slurry treatment system 6 by a slurry concentration method. At the same time, the mixed gas washed by the liquid phase enters the heat exchanger from the first outlet at the top of the scrubbing tower 41. The heat exchanger condenses the mixed gas and sends it back into the scrubbing tower 41. The condensed mixed gas serves as the liquid phase in the scrubbing tower 41 and is used to scrub the mixed gas continuously entering the scrubbing tower 41. The liquid phase in the scrubbing tower 41 also includes silicon tetrachloride liquid added during pre-start-up, but the main liquid phase is the condensed mixed gas. The scrubbed mixed gas exits from the first outlet of the scrubbing tower 41 and enters the first condenser 42. The condensed crude chlorosilane then enters the de-heavy purification system 5 from the chlorosilane outlet of the first condenser 42.

[0042] (4) De-lamination and purification system 5: The de-lamination and purification system 5 separates tetrachlorosilane and high-boiling-point substances from the crude chlorosilane product. Specifically, the crude chlorosilane product after wet dust removal enters the de-lamination and purification system 5 for component separation and impurity removal. The key control point of this operation is that the crude chlorosilane product enters the de-lamination tower 51, and the different components are separated based on their different boiling points under gas partial pressure. In the de-lamination tower 51, trichlorosilane is collected from the top, silicon tetrachloride is collected from the middle and lower parts, and metallic hydrogen chloride and high-boiling-point substances are concentrated in the bottom of the tower to ensure the purity of the components throughout the separation process. The degravity purification process is carried out at a constant pressure of 0.2 MPa. To ensure that the purity of the trichlorosilane extracted from the top reaches 99.9%, the trichlorosilane is then adsorbed by a carbon adsorption tower 52 to effectively remove B and P impurities from the trichlorosilane, resulting in high-purity trichlorosilane for use in polysilicon production. The silicon tetrachloride trichlorosilane content from the side extraction port is below 1%, which is used in the cold hydrogenation workshop for the production of chlorosilanes. The waste gas extracted from the tower bottom is sent to the slurry treatment system 6.

[0043] According to some embodiments of the present invention, the device further includes: a silicon powder feeding system 1; the silicon powder feeding system 1 includes: a silicon powder feeding tank 12 and a hydrogen chloride gas conveying pipeline 13, the outlet of the hydrogen chloride gas conveying pipeline 13 being connected to the interior of the silicon powder feeding tank 12, and the outlet of the silicon powder feeding tank 12 being connected to the interior of the trichlorosilane reactor 21.

[0044] Preferably, the silicon powder feeding system 1 further includes a silicon powder silo 11, a silicon powder buffer tank 14, a silicon powder filter 15, and a nitrogen venting tank 16; the outlet of the silicon powder silo 11 is connected to the hydrogen chloride gas conveying pipeline 13, the top of the silicon powder feeding tank 12 is provided with a silicon powder return port, the silicon powder return port is connected to the inlet of the silicon powder filter 15, and the outlet of the silicon powder filter 15 is connected to the nitrogen venting tank 16.

[0045] In the silicon powder feeding system 1 provided in this invention, during the feeding process, nitrogen gas is used to transport silicon powder from the silicon powder silo 11 to the silicon powder feeding tank 12. To remove impurities such as dust from the silicon powder, the silicon powder entering the silicon powder feeding tank 12 is filtered again in the silicon powder filter 15. At the same time, the nitrogen gas used to blow the silicon powder enters the nitrogen vent tank 16. The silicon powder in the silicon powder feeding tank 12 enters the silicon powder buffer tank 14 under gravity. During this process, hydrogen chloride gas is blown through the hydrogen chloride gas delivery pipeline 13, using hydrogen chloride gas as a medium to push the silicon powder into the trichlorosilane synthesis system 2.

[0046] According to some embodiments of the present invention, the apparatus further includes: a hydrogen chloride raw material pipeline 8; the outlet of the hydrogen chloride raw material pipeline 8 is connected to the interior of the trichlorosilane reactor 21. Preferably, a hydrogen chloride buffer tank 81 is also provided between the hydrogen chloride raw material pipeline 8 and the trichlorosilane reactor 21. The raw materials for preparing trichlorosilane in the present invention are silicon powder and hydrogen chloride gas, wherein the raw material silicon powder is added to the trichlorosilane reactor 21 through the silicon powder feeding system 1 described above, and the raw material hydrogen chloride is by-product hydrogen chloride from the chlor-alkali production process and hydrogen chloride from the hydrochloric acid desorption process. The hydrogen chloride from these two sources is dried and dehydrated before being used as the raw material hydrogen chloride in the present invention.

[0047] According to some embodiments of the present invention, the trichlorosilane reactor 21 uses condensate for cooling. The shell of the trichlorosilane reactor 21 is connected to a condensate pipe 22 and a steam pipe 23, respectively. The condensate enters the trichlorosilane reactor 21 from the condensate pipe 22, and the condensate is heated into steam and then discharged from the steam pipe 23.

[0048] According to some embodiments of the present invention, the dry dust removal system 3 further includes: a primary bag filter 32 and a secondary bag filter 33; the inlet of the primary bag filter 32 is connected to the outlet of the cyclone separator 31, and the outlet of the primary bag filter 32 is connected to the first inlet of the scrubbing tower 41 and the inlet of the secondary bag filter 33, respectively.

[0049] According to some embodiments of the present invention, the silicon powder in the silicon powder feeding tank 12 is silicon powder with a particle size of 40-325 mesh. After the silicon powder in the mixed gas is processed by the cyclone separator 31, 98% of the silicon powder can be separated. The remaining approximately 2% of fine silicon powder enters the primary bag filter 32 and the secondary bag filter 33. The secondary bag filter 33 has a higher filtration accuracy than the primary bag filter 32. Silicon dust that cannot be separated at around 10 micrometers is separated by the primary bag filter 32. The separated mixture enters the wet dust removal system 4. This portion of extremely fine silicon dust is not recovered and is directly discharged into the silicon powder bag 34. Currently, the silicon powder used in this industry has common particle sizes of 40-160 mesh, 20-160 mesh, 20-200 mesh, and 40-120 mesh. The 40-325 mesh silicon powder used in this invention is the scrap material of these industry-standard silicon powders. By setting up the dry dust removal system 3, this invention expands the range of usable silicon powder particle sizes, thereby making full use of the scrap material of industry-standard silicon powder, reducing production costs and waste.

[0050] According to some embodiments of the present invention, the slurry treatment system 6 includes a thickening tower 64, the outlet of which is connected to the inlet of the de-heavyweight tower 51. The waste gas entering the slurry treatment system 6 from the bottom of the scrubbing tower 41 and the bottom of the de-heavyweight tower 51, as described above, enters the thickening tower 64, is concentrated, and then recycled back to the de-heavyweight tower 51, effectively realizing the product recycling process. Simultaneously, the remaining high-boiling-point substances are sent to a high-boiling-point cracking unit for use. The entire recycling process is carried out in a regenerative manner.

[0051] Preferably, see Appendix Figure 1 The slurry treatment system 6 also includes: a settling tank 61, a dryer 62, a condensation recovery device 63, a second condenser 65, a hydrolysis device 66, a second waste gas tank 67, and a high-boiling-point tank 68. The waste gas entering the slurry treatment system 6 from the bottom of the scrubbing tower 41 and the bottom of the de-weighing tower 51 undergoes separate treatments such as settling, drying, condensation, evaporation concentration, and hydrolysis. The waste gas then enters the second waste gas tank 67. The mixed gas from the top outlet of the concentration tower 64 re-enters the de-weighing tower 51. The high-boiling-point substances collected from the bottom of the concentration tower 64 enter the high-boiling-point tank 68 and are sent to the high-boiling-point cracking device for use. The high-boiling-point substances are thus effectively utilized and recovered.

[0052] According to some embodiments of the present invention, the heavy metal removal and purification system 5 includes a trichlorosilane product storage tank 53 and a tetrachlorosilane product storage tank 54; the outlet of the carbon adsorption tower 52 is connected to the interior of the trichlorosilane product storage tank 53; the side intake of the heavy metal removal tower 51 is connected to the interior of the tetrachlorosilane product storage tank 54. Trichlorosilane is collected from the top of the heavy metal removal tower 51, and silicon tetrachloride is collected from the middle and lower parts. The trichlorosilane collected from the top of the heavy metal removal tower 51 enters the trichlorosilane product storage tank 53 after passing through the carbon adsorption tower 52. The silicon tetrachloride collected from the middle and lower parts of the heavy metal removal tower 51 enters the middle and lower side silicon tetrachloride collection tank.

[0053] According to some embodiments of the present invention, the trichlorosilane reactor 21 is a fluidized bed.

[0054] According to some embodiments of the present invention, the wet dust removal system 4 includes at least two scrubbing towers 41 connected in series; and / or the heavy metal removal and purification system 5 includes at least two carbon adsorption towers 52 connected in series. In this invention, to ensure the effect of impurity removal, multiple scrubbing towers 41 and multiple carbon adsorption towers 52 can be connected in series.

[0055] According to some embodiments of the present invention, the device further includes: a hydrogen recovery system 7; the first condenser 42 is also provided with a gas outlet, which is connected to the hydrogen recovery system 7.

[0056] In summary, the advantages of the trichlorosilane preparation apparatus of this invention are as follows: it combines the pneumatic conveying method for silicon powder in the entire polysilicon industry, energy-saving technology using heat exchanger condensate mixed gas as the liquid phase for scrubbing, energy-saving means for bidirectional extraction of trichlorosilane and tetrachlorosilane components, and slurry concentration and recovery technology, achieving effective resource integration of the entire system and fully realizing the technical effects of low energy consumption and recycling. This creates a self-operating, self-compensating high-purity trichlorosilane production technology. This invention recovers approximately 98% of the silicon powder, overcoming the current problem of unusable silicon powder resources in the traditional trichlorosilane industry. It also fully utilizes the scraps from commonly used silicon powder in the industry as raw materials, reducing production costs and waste. It solves the problems of low-quality chlorosilanes and low automation, producing not only crude chlorosilanes but also purified silicon tetrachloride and high-boiling-point substances. Furthermore, the trichlorosilane prepared using the apparatus of this invention meets current industry standards for external sales, with a BP content below 150 ppb.

[0057] Secondly, the present invention provides a method for preparing trichlorosilane, the method utilizing the apparatus described above.

[0058] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0059] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An apparatus for preparing trichlorosilane, characterized in that, include: Trichlorosilane synthesis system, dry dust removal system, wet dust removal system, heavy weight removal and purification system, and slurry treatment system; The trichlorosilane synthesis system includes a trichlorosilane reactor; the dry dust removal system includes a cyclone separator; the wet dust removal system includes a scrubbing tower, a reboiler, a heat exchanger, and a first condenser. The scrubbing tower includes a tower body and a tower plate. The sidewalls of the scrubbing tower body are respectively provided with a first inlet and a second inlet. The top of the scrubbing tower body is provided with a first outlet, and the bottom of the scrubbing tower body is provided with a second outlet. The first condenser is provided with a chlorosilane inlet and a chlorosilane outlet. The heavy metal removal and purification system includes a heavy metal removal tower and a carbon adsorption tower. The sidewalls of the heavy metal removal tower are provided with a heavy metal removal tower inlet, and the opposite side of the heavy metal removal tower inlet is provided with a heavy metal removal tower side outlet. The top of the heavy metal removal tower is provided with a trichlorosilane outlet, and the bottom of the heavy metal removal tower is provided with a waste gas outlet. The outlet at the top of the trichlorosilane reactor is connected to the inlet of the cyclone separator; the outlet of the cyclone separator is connected to the inlet of the side wall of the trichlorosilane reactor and the first inlet of the scrubbing tower; the second outlet of the scrubbing tower is connected to the inlet of the reboiler, and the outlet of the reboiler is connected to the slurry treatment system; the first outlet of the scrubbing tower is connected to the inlet of the heat exchanger, and the outlet of the heat exchanger is connected to the second inlet of the scrubbing tower; the first outlet of the scrubbing tower is also connected to the chlorosilane inlet of the first condenser; the chlorosilane outlet of the first condenser is connected to the inlet of the heavy silane removal tower; the trichlorosilane outlet of the heavy silane removal tower is connected to the inlet of the carbon adsorption tower; and the exhaust gas outlet of the heavy silane removal tower is connected to the slurry treatment system.

2. The apparatus according to claim 1, characterized in that, The device also includes: Silicon powder feeding system and hydrogen chloride raw material pipeline; The silicon powder feeding system includes: a silicon powder feeding tank and a hydrogen chloride gas conveying pipeline. The outlet of the hydrogen chloride gas conveying pipeline is connected to the interior of the silicon powder feeding tank, and the outlet of the silicon powder feeding tank is connected to the interior of the trichlorosilane reactor. The outlet of the hydrogen chloride raw material pipeline is connected to the interior of the trichlorosilane reactor.

3. The apparatus according to claim 2, characterized in that, The silicon powder in the silicon powder feeding tank has a particle size of 40-325 mesh.

4. The apparatus according to claim 1, characterized in that, The slurry treatment system includes a thickening tower, the outlet of which is connected to the inlet of the de-weighting tower.

5. The apparatus according to claim 1, characterized in that, The dry dust removal system also includes: Primary bag filter and secondary bag filter; The inlet of the primary bag filter is connected to the outlet of the cyclone separator, and the outlet of the primary bag filter is connected to the first inlet of the scrubbing tower and the inlet of the secondary bag filter.

6. The apparatus according to claim 1, characterized in that, The degravity removal and purification system includes a trichlorosilane product storage tank and a tetrachlorosilane product storage tank. The outlet of the carbon adsorption tower is connected to the interior of the trichlorosilane product storage tank; The side port of the deweight removal tower is connected to the interior of the tetrachlorosilane product storage tank.

7. The apparatus according to claim 1, characterized in that, The trichlorosilane reactor is a fluidized bed.

8. The apparatus according to claim 1, characterized in that, The wet dust removal system includes at least two scrubbing towers connected in series; and / or The degravity removal and purification system includes at least two carbon adsorption towers connected in series.

9. The apparatus according to claim 1, characterized in that, The device also includes: Hydrogen recovery system; The first condenser is also provided with a gas outlet, which is connected to the hydrogen recovery system.

10. A method for preparing trichlorosilane, characterized in that, The method utilizes the apparatus according to any one of claims 1 to 9.

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