Energy-saving efficient chlorosilane separation system

Abstract

The utility model discloses an energy-saving high-efficiency chlorosilane separation system, which belongs to the technical field of polycrystalline silicon production and is characterized in that dichlorosilane and silicon tetrachloride are discharged in a first rectifying tower, heat of a first tower kettle produced liquid is recycled through a preheater, and heat of a first tower top produced liquid is recycled through a second reboiler; heavy impurities in trichlorosilane are removed in the second rectifying tower, light impurities in trichlorosilane are removed in the third rectifying tower, and heat of third tower top produced liquid is recycled through a fourth reboiler; heavy impurities of trichlorosilane in the fourth rectifying tower are further removed, and pure trichlorosilane is discharged through a trichlorosilane extraction pipe. According to the device, chlorosilane can be efficiently separated to obtain pure trichlorosilane, heat can be effectively recovered, and energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the polycrystalline silicon production technical field, concretely relates to an energy -conserving high -efficient chlorosilane separation system. BACKGROUND

[0002] Trichlorosilane rectification is one of the core technologies of polycrystalline silicon production process, and the degree of trichlorosilane purification directly affects the purity of the final product polycrystalline silicon, and the purity of polycrystalline silicon affects the power generation effect of downstream solar cells. The raw materials of polycrystalline silicon production, such as silicon powder, hydrogen, hydrogen chloride and intermediate products produced in each process in chemical reaction, contain phosphorus, boron and metal impurities that affect the quality of polycrystalline silicon.

[0003] Most of the existing electronic grade polycrystalline silicon production adopts improved Siemens method, and adopts a five-stage or six-stage rectification tower series rectification system to separate hydrogenation liquid raw materials. Because of the existence of impurities, part of the chlorosilane raw materials cannot be completely recycled. It is usually impossible to meet the needs of electronic grade polycrystalline silicon production, and there are problems such as high energy consumption and low material utilization.

[0004] Most of the polycrystalline silicon production enterprises currently adopt multi-tower rectification for rectification and purification, usually adopting a 5-stage rectification process, and the process is as follows: coarse separation tower → light removal tower → heavy removal tower → light removal tower → heavy removal tower. The problems of this process are as follows: ① The multi-stage rectification equipment investment is large; ② The separation effect of each rectification tower is not good, which easily causes large tower cutting, low product recovery rate, high energy consumption, and also easily causes unqualified products; ③ The material is high, and the recycling rate is low; ④ The product quality is unstable due to the influence of raw material impurities.

[0005] The Chinese patent with publication number CN116534864A and publication date 2023-08-04 discloses a chlorosilane rectification and impurity removal process and system in polycrystalline silicon production. The raw material chlorosilane passes through the raw material adsorption tower to remove part of the impurities; the impurity-removed raw material chlorosilane enters the coarse separation tower, the dichlorodihydrogen silicon and light impurities are cut off from the top of the tower, the silicon tetrachloride and heavy impurities are cut off from the tower kettle, the trichlorosilane is taken out from the middle side line of the tower and enters the light removal tower, the light impurities are cut off from the upper tower top of the light removal tower, and the material taken out from the lower tower kettle of the light removal tower enters the heavy removal tower; the heavy impurities are cut off from the lower tower kettle of the heavy removal tower, and the qualified trichlorosilane product is taken out from the upper tower top of the heavy removal tower; after all the cut-off impurities are recycled, they are sent into the post-reversion separation tower for component separation, the separated dichlorodihydrogen silicon and silicon tetrachloride are mixed and sent into the reversion reactor for reversion reaction to generate trichlorosilane, and the generated trichlorosilane, unreacted dichlorodihydrogen silicon and silicon tetrachloride re-enter the post-reversion separation tower for component separation; the trichlorosilane is separated from the side line of the post-reversion separation tower and returned for rectification and impurity removal. The patent has the shortcomings of not fully utilizing heat and high energy consumption. UTILITY MODEL CONTENTS

[0006] To address the aforementioned technical problems, this invention provides an energy-efficient and high-performance chlorosilane separation system. In a first distillation column, dichlorosilane and silicon tetrachloride are discharged. The heat from the bottom liquid of the first column is recovered and reused via a preheater, and the heat from the top liquid of the first column is recovered and reused via a second reboiler. In a second distillation column, heavy impurities in trichlorosilane are removed. In a third distillation column, light impurities in trichlorosilane are removed. The heat from the top liquid of the third column is recovered and reused via a fourth reboiler. In a fourth distillation column, heavy impurities in trichlorosilane are further removed, and the pure trichlorosilane is discharged through a trichlorosilane outlet pipe. This invention can efficiently separate chlorosilanes to obtain pure trichlorosilane and can effectively recover heat, reducing energy consumption.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] An energy-efficient and high-performance chlorosilane separation system includes a first distillation column, which is equipped with a first feed pipe, a first top outlet pipe, a side outlet pipe, and a first bottom outlet pipe. A first preheater is installed on the first feed pipe. The first top outlet pipe is connected to a second reboiler and a first separation tank. The first separation tank is equipped with a first reflux pipe and a dichlorosilane outlet pipe. The first reflux pipe is connected to the first distillation column. The first bottom outlet pipe is connected to a silicon tetrachloride outlet pipe via the first preheater. The side outlet pipe is connected to a second distillation column. The second distillation column is equipped with a second top outlet pipe and a second bottom outlet pipe. The second top outlet pipe is connected to a second separation tank. The second separation tank is equipped with... The system is equipped with a second reflux pipe and a second feed pipe. The second reflux pipe is connected to a second distillation column, and the second feed pipe is connected to a third distillation column. The third distillation column is equipped with a third top outlet pipe and a third bottom outlet pipe. The third top outlet pipe is connected to a fourth reboiler and a third separator. The third separator is equipped with a third reflux pipe and a waste discharge pipe. The third reflux pipe is connected to the third distillation column, and the third bottom outlet pipe is connected to a fourth distillation column. The fourth distillation column is equipped with a fourth top outlet pipe and a fourth bottom outlet pipe. The fourth top outlet pipe is connected to a fourth separator. The fourth separator is equipped with a fourth reflux pipe and a trichlorosilane outlet pipe. The fourth reflux pipe is connected to the fourth distillation column.

[0009] Preferably, the first distillation column is provided with a first pressure control unit, which includes a first pressure sensor provided on the first distillation column, a first exhaust pipe provided on the first separation tank, and a first pressure regulating valve provided on the first exhaust pipe.

[0010] Preferably, the second distillation column is provided with a second pressure control unit, which includes a second pressure sensor provided on the second distillation column, a second exhaust pipe provided on the second separation tank, and a second pressure regulating valve provided on the second exhaust pipe.

[0011] Preferably, the third distillation column is provided with a third pressure control unit, which includes a third pressure sensor installed on the third distillation column, a third exhaust pipe installed on the third separation tank, and a third pressure regulating valve installed on the third exhaust pipe.

[0012] Preferably, the fourth distillation column is provided with a fourth pressure control unit, which includes a fourth pressure sensor provided on the fourth distillation column, a fourth exhaust pipe provided on the fourth separation tank, and a fourth pressure regulating valve provided on the fourth exhaust pipe.

[0013] Preferably, the first distillation column is provided with a first temperature control unit, which includes a first temperature sensor provided on the first distillation column, a first steam pipe provided on the first reboiler, and a first steam regulating valve on the first steam pipe.

[0014] Preferably, the third distillation column is provided with a third temperature control unit, which includes a third temperature sensor provided on the third distillation column, a third steam pipe provided on the third reboiler, and a third steam regulating valve on the third steam pipe.

[0015] Preferably, the first distillation column is provided with a first liquid level control unit, which includes a first liquid level sensor provided on the first distillation column and a first reboiler discharge valve provided on the reboiler discharge pipe of the first column.

[0016] Preferably, the second distillation column is provided with a second liquid level control unit, which includes a second liquid level sensor provided on the second distillation column and a second column bottom discharge valve provided on the second column bottom discharge pipe.

[0017] Preferably, the fourth distillation column is provided with a fourth liquid level control unit, which includes a fourth liquid level sensor installed on the fourth distillation column and a fourth column bottom discharge valve installed on the bottom discharge pipe of the fourth column.

[0018] The beneficial effects of this technical solution are as follows:

[0019] I. This utility model provides an energy-saving and efficient chlorosilane separation system. Chlorosilane feedstock enters a first distillation column through a first feed pipe for initial distillation separation. Silicon tetrachloride is discharged from the first distillation column through a bottom outlet pipe. The silicon tetrachloride collected from the bottom of the column is used as a heat source for a preheater to preheat the chlorosilane feedstock. Dichlorosilane is discharged from the first distillation column through a top outlet pipe. The dichlorosilane collected from the top of the column is used as a heat source for a second reboiler, and then flows into a first separation tank for gas-liquid separation. Part of the dichlorosilane is returned to the first distillation column through a first reflux pipe, and part of the dichlorosilane is discharged through a dichlorosilane outlet pipe. Trichlorosilane flows into a second distillation column through a side outlet pipe. A second distillation separation is performed in the second distillation column. The heavy liquid is discharged from the second distillation column through a bottom outlet pipe, and the top of the second distillation column is... The liquid flows into the second separation tank for gas-liquid separation. Part of the liquid from the top of the second column flows back to the second rectification column through the second reflux pipe, and part flows into the third rectification column. A third rectification separation occurs in the third rectification column, and the light impurity is discharged from the top pipe of the third column. This light impurity serves as a heat source for the fourth reboiler and then flows into the third separation tank for gas-liquid separation. Part of the light impurity flows back to the third rectification column through the third reflux pipe, and part is discharged through the discharge pipe. The liquid from the bottom of the third column flows into the fourth rectification column for a fourth rectification separation. The second heavy impurity is discharged through the bottom pipe of the fourth column and flows into the fourth separation tank through the top pipe of the fourth column. A portion of the pure trichlorosilane flows back to the fourth rectification column through the fourth reflux pipe, and a portion of the pure trichlorosilane flows out through the trichlorosilane discharge pipe. This invention can efficiently separate chlorosilanes to obtain pure trichlorosilane and can effectively recover heat, reducing energy consumption.

[0020] II. The present invention provides an energy-saving and efficient chlorosilane separation system, wherein the setting of a first pressure control unit, a second pressure control unit, a third pressure control unit and a fourth pressure control unit effectively controls the pressure in the first distillation column, the second distillation column, the third distillation column and the fourth distillation column.

[0021] III. The energy-saving and efficient chlorosilane separation system provided by this utility model has a first temperature control unit and a third temperature control unit, which effectively control the amount of steam entering, ensuring the normal operation of distillation separation and avoiding steam waste.

[0022] IV. The present invention provides an energy-saving and efficient chlorosilane separation system, wherein the setting of a first liquid level control unit, a second liquid level control unit and a fourth liquid level control unit effectively controls the liquid level in the first distillation column, the second distillation column and the fourth distillation column. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] Wherein: 100, First distillation column; 111, First feed pipe; 112, First column top outlet pipe; 113, Side outlet pipe; 114, First column bottom outlet pipe; 115, First preheater; 120, First separator; 121, First reflux pipe; 122, Dichlorosilane outlet pipe; 130, First pressure control unit; 131, First pressure sensor; 132, First exhaust pipe; 133, First pressure regulating valve; 140, First temperature control unit; 141, First temperature sensor; 142, First... 143. Steam pipe; 150. First steam regulating valve; 151. First liquid level control unit; 152. First liquid level sensor; 153. First column bottom discharge valve; 200. Second distillation column; 211. Second column top outlet pipe; 212. Second column bottom outlet pipe; 220. Second reboiler; 230. Second separator; 231. Second reflux pipe; 232. Second feed pipe; 240. Second pressure control unit; 241. Second pressure sensor; 242. Second exhaust pipe; 243. Second pressure regulating valve; 25 0. Second liquid level control unit; 251. Second liquid level sensor; 252. Second column bottom discharge valve; 300. Third distillation column; 311. Third column top outlet pipe; 312. Third column bottom outlet pipe; 320. Third separator; 321. Third reflux pipe; 322. Impurity discharge pipe; 330. Third pressure control unit; 331. Third pressure sensor; 332. Third exhaust pipe; 333. Third pressure regulating valve; 340. Third temperature control unit; 341. Third temperature sensor; 342. Third... Steam pipe; 343, Third steam regulating valve; 400, Fourth distillation column; 411, Fourth column top outlet pipe; 412, Fourth column bottom outlet pipe; 420, Fourth separator; 421, Fourth reflux pipe; 422, Trichlorosilane outlet pipe; 430, Fourth reboiler; 440, Fourth pressure control unit; 441, Fourth pressure sensor; 442, Fourth exhaust pipe; 443, Fourth pressure regulating valve; 450, Fourth liquid level control unit; 451, Fourth liquid level sensor; 452, Fourth column bottom outlet valve. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0026] Example 1

[0027] like Figure 1As shown, an energy-efficient chlorosilane separation system includes a first distillation column 100. The first distillation column 100 is equipped with a first feed pipe 111, a first top outlet pipe 112, a side outlet pipe 113, and a first bottom outlet pipe 114. A first preheater 115 is installed on the first feed pipe 111. The first top outlet pipe 112 is connected to a second reboiler 220 and a first separation tank 120. The first separation tank 120 is equipped with a first reflux pipe 121 and a second... A silicon chloride outlet pipe 122 is provided; the first reflux pipe 121 is connected to the first distillation column 100; the first column bottom outlet pipe 114 is connected to the silicon tetrachloride outlet pipe via the first preheater 115; the side outlet pipe 113 is connected to the second distillation column 200; the second distillation column 200 is provided with a second column top outlet pipe 211 and a second column bottom outlet pipe 212; the second column top outlet pipe 211 is connected to the second separation tank 230; the second separation tank 230 is provided with a second... A second reflux pipe 231 and a second feed pipe 232 are connected. The second reflux pipe 231 is connected to the second distillation column 200, and the second feed pipe 232 is connected to the third distillation column 300. The third distillation column 300 is equipped with a third top outlet pipe 311 and a third bottom outlet pipe 312. The third top outlet pipe 311 is connected to the fourth reboiler 430 and the third separator 320. The third separator 320 is equipped with a third reflux pipe 321 and a waste discharge pipe 322. The third reflux pipe 321 is connected to the third distillation column 300, and the third column bottom outlet pipe 312 is connected to the fourth distillation column 400. The fourth distillation column 400 is provided with a fourth column top outlet pipe 411 and a fourth column bottom outlet pipe 412. The fourth column top outlet pipe 411 is connected to the fourth separation tank 420. The fourth separation tank 420 is provided with a fourth reflux pipe 421 and a trichlorosilane outlet pipe 422. The fourth reflux pipe 421 is connected to the fourth distillation column 400.

[0028] Example 2

[0029] The difference between this embodiment and Embodiment 1 is that a first pressure control unit 130 is provided on the first distillation column 100. The first pressure control unit 130 includes a first pressure sensor 131 installed on the first distillation column 100, a first exhaust pipe 132 installed on the first separation tank 120, and a first pressure regulating valve 133 installed on the first exhaust pipe 132. The pressure detected at the first pressure sensor 131 is transmitted to the DCS controller. The DCS controller controls the first pressure regulating valve 133 according to the preset pressure value of the first distillation column 100. If the pressure detected at the first pressure sensor 131 is greater than the preset value, the valve opening of the first pressure regulating valve 133 is increased (until fully open); if the pressure detected at the first pressure sensor 131 is less than the preset value, the valve opening of the first pressure regulating valve 133 is decreased (until fully closed), thus ensuring the pressure inside the first distillation column 100 is stable.

[0030] The second distillation column 200 is equipped with a second pressure control unit 240, which includes a second pressure sensor 241 on the second distillation column 200, a second exhaust pipe 242 on the second separation tank 230, and a second pressure regulating valve 243 on the second exhaust pipe 242. The pressure detected by the second pressure sensor 241 is transmitted to the DCS controller. The DCS controller controls the second pressure regulating valve 243 according to the preset pressure value of the second distillation column 200. If the pressure detected by the second pressure sensor 241 is greater than the preset value, the valve opening of the second pressure regulating valve 243 is increased (until it is fully open); if the pressure detected by the second pressure sensor 241 is less than the preset value, the valve opening of the second pressure regulating valve 243 is decreased (until it is fully closed), thus ensuring the pressure inside the second distillation column 200 is stable.

[0031] The third distillation column 300 is equipped with a third pressure control unit 330, which includes a third pressure sensor 331 on the third distillation column 300, a third exhaust pipe 332 on the third separation tank 320, and a third pressure regulating valve 333 on the third exhaust pipe 332. The pressure detected by the third pressure sensor 331 is transmitted to the DCS controller. The DCS controller controls the third pressure regulating valve 333 according to the preset pressure value of the third distillation column 300. If the pressure detected by the third pressure sensor 331 is greater than the preset value, the valve opening of the third pressure regulating valve 333 is increased (until it is fully open); if the pressure detected by the third pressure sensor 331 is less than the preset value, the valve opening of the third pressure regulating valve 333 is decreased (until it is fully closed), thus ensuring the pressure stability within the third distillation column 300.

[0032] The fourth distillation column 400 is equipped with a fourth pressure control unit 440, which includes a fourth pressure sensor 441 mounted on the fourth distillation column 400, a fourth exhaust pipe 442 mounted on the fourth separation tank 420, and a fourth pressure regulating valve 443 mounted on the fourth exhaust pipe 442. The pressure detected by the fourth pressure sensor 441 is transmitted to the DCS controller. The DCS controller controls the fourth pressure regulating valve 443 according to a preset pressure value of the fourth distillation column 400. If the pressure detected by the fourth pressure sensor 441 is greater than the preset value, the valve opening of the fourth pressure regulating valve 443 is increased (until fully open); if the pressure detected by the fourth pressure sensor 441 is less than the preset value, the valve opening of the fourth pressure regulating valve 443 is decreased (until fully closed), thus ensuring pressure stability within the fourth distillation column 400.

[0033] The first distillation column 100 is equipped with a first temperature control unit 140, which includes a first temperature sensor 141 on the first distillation column 100, a first steam pipe 142 on the first reboiler, and a first steam regulating valve 143 on the first steam pipe 142. The temperature detected by the first temperature sensor 141 is transmitted to the DCS controller. The DCS controller controls the first steam regulating valve 143 according to the preset temperature value of the first distillation column 100. If the temperature detected by the first temperature sensor 141 is greater than the preset value, the valve opening of the first steam regulating valve 143 is reduced (until it is fully closed); if the temperature detected by the first temperature sensor 141 is less than the preset value, the valve opening of the first steam regulating valve 143 is increased (until it is fully open), thus ensuring temperature stability within the first distillation column 100.

[0034] The third distillation column 300 is equipped with a third temperature control unit 340, which includes a third temperature sensor 341 mounted on the third distillation column 300, a third steam pipe 342 mounted on the third reboiler, and a third steam regulating valve 343 mounted on the third steam pipe 342. The temperature detected by the third temperature sensor 341 is transmitted to the DCS controller. The DCS controller controls the third steam regulating valve 343 according to the preset temperature value of the third distillation column 300. If the temperature detected by the third temperature sensor 341 is greater than the preset value, the valve opening of the third steam regulating valve 343 is reduced (until it is fully closed); if the temperature detected by the third temperature sensor 341 is less than the preset value, the valve opening of the third steam regulating valve 343 is increased (until it is fully open), thus ensuring temperature stability within the third distillation column 300.

[0035] The first distillation column 100 is equipped with a first liquid level control unit 150, which includes a first liquid level sensor 151 mounted on the first distillation column 100 and a first reboiler discharge valve 152 mounted on the first reboiler outlet pipe 114. The liquid level detected by the first liquid level sensor 151 is transmitted to the DCS controller. The DCS controller controls the first reboiler discharge valve 152 according to the preset liquid level value of the first distillation column 100. If the liquid level detected by the first liquid level sensor 151 is greater than the preset value, the valve opening of the first reboiler discharge valve 152 is increased (until fully open); if the liquid level detected by the first liquid level sensor 151 is less than the preset value, the valve opening of the first reboiler discharge valve 152 is decreased (until fully closed), thus ensuring the stability of the liquid level in the first distillation column 100.

[0036] The second distillation column 200 is equipped with a second liquid level control unit 250, which includes a second liquid level sensor 251 mounted on the second distillation column 200 and a second column bottom discharge valve 252 mounted on the second column bottom outlet pipe 212. The liquid level detected by the second liquid level sensor 251 is transmitted to the DCS controller. The DCS controller controls the second column bottom discharge valve 252 according to the preset liquid level value of the second distillation column 200. If the liquid level detected by the second liquid level sensor 251 is greater than the preset value, the valve opening of the second column bottom discharge valve 252 is increased (until it is fully open); if the liquid level detected by the second liquid level sensor 251 is less than the preset value, the valve opening of the second column bottom discharge valve 252 is decreased (until it is fully closed), thus ensuring the stability of the liquid level in the second distillation column 200.

[0037] The fourth distillation column 400 is equipped with a fourth liquid level control unit 450, which includes a fourth liquid level sensor 451 installed on the fourth distillation column 400 and a fourth column reboiler discharge valve 452 installed on the fourth column reboiler outlet pipe 412. The liquid level detected by the fourth liquid level sensor 451 is transmitted to the DCS controller. The DCS controller controls the fourth column reboiler discharge valve 452 according to the preset liquid level value of the fourth distillation column 400. If the liquid level detected by the fourth liquid level sensor 451 is greater than the preset value, the valve opening of the fourth column reboiler discharge valve 452 is increased (until it is fully open); if the liquid level detected by the fourth liquid level sensor 451 is less than the preset value, the valve opening of the fourth column reboiler discharge valve 452 is decreased (until it is fully closed), thus ensuring the stability of the liquid level in the fourth distillation column 400.

[0038] The beneficial effects of this technical solution are as follows:

[0039] I. This utility model provides an energy-saving and efficient chlorosilane separation system. The chlorosilane feedstock enters the first distillation column 100 through the first feed pipe 111 for the first distillation separation. Silicon tetrachloride is discharged from the first distillation column 100 through the first column bottom outlet pipe 114. The silicon tetrachloride collected from the bottom of the column is used as a heat source for the preheater to preheat the chlorosilane feedstock. Dichlorosilane is discharged from the first distillation column 100 through the first column top outlet pipe 112. The dichlorosilane collected from the top of the column is used as a second reboiler. The heat source of the device 220 then flows into the first separator 120 for gas-liquid separation. Part of the dichlorosilane is discharged back to the first distillation column 100 through the first reflux pipe 121, and part of the dichlorosilane is discharged through the dichlorosilane outlet pipe 122. Trichlorosilane flows into the second distillation column 200 through the side outlet pipe 113. In the second distillation column 200, a second distillation separation is performed. The heavy liquid is discharged from the second distillation column 200 through the second column bottom outlet pipe 212, and the liquid collected from the top of the second column flows into the first distillation column 100. In the second separator 230, gas-liquid separation takes place. Part of the liquid collected from the top of the second column flows back to the second rectification column 200 through the second reflux pipe 231, while another part flows into the third rectification column 300. In the third rectification column 300, a third rectification separation takes place. Light impurities are discharged through the third column top pipe 311. These light impurities serve as a heat source for the fourth reboiler 430 and subsequently flow into the third separator 320 for further gas-liquid separation. A portion of the light impurities flows back to the third separation column through the third reflux pipe 321. In distillation column 300, a portion of the light impurities are discharged through discharge pipe 322. The bottom product of the third column flows into the fourth distillation column 400, where a fourth distillation separation is performed. The second heavy impurities are discharged through bottom product pipe 412 and flow into the fourth separation tank 420 through top product pipe 411. A portion of the pure trichlorosilane flows back to the fourth distillation column 400 through the fourth reflux pipe 421, and a portion of the pure trichlorosilane flows out through the trichlorosilane product pipe 422. This invention can efficiently separate chlorosilanes to obtain pure trichlorosilane and can effectively recover heat, reducing energy consumption.

[0040] II. The present invention provides an energy-saving and efficient chlorosilane separation system, wherein the first pressure control unit 130, the second pressure control unit 240, the third pressure control unit 330 and the fourth pressure control unit 440 are set up to effectively control the pressure in the first distillation column 100, the second distillation column 200, the third distillation column 300 and the fourth distillation column 400.

[0041] III. The energy-saving and efficient chlorosilane separation system provided by this utility model, with the setting of the first temperature control unit 140 and the third temperature control unit 340, effectively controls the amount of steam entering, which can not only ensure the normal operation of distillation separation, but also avoid the waste of steam.

[0042] IV. The present invention provides an energy-saving and efficient chlorosilane separation system, wherein the first liquid level control unit 150, the second liquid level control unit 250 and the fourth liquid level control unit 450 are set to effectively control the liquid level in the first distillation column 100, the second distillation column 200 and the fourth distillation column 400.

[0043] Example 3

[0044] This embodiment uses an energy-saving and efficient chlorosilane separation system as described in Example 2, wherein the first pressure sensor 131 is controlled at 600-700 kPa; the first temperature sensor 141 is controlled at 103-111°C; the first liquid level sensor 151 is controlled at 50-80%; the second pressure sensor 241 is controlled at 100-200 kPa; the second liquid level sensor 251 is controlled at 50-80%; the third pressure sensor 331 is controlled at 350-450 kPa; the third temperature sensor 341 is controlled at 82-93°C; the fourth pressure sensor 441 is controlled at 50-150 kPa; and the fourth liquid level sensor 451 is controlled at 50-80%.

[0045] The first distillation column 100 is a partitioned column; a first reboiler is installed on the first distillation column 100, and a third reboiler is installed on the third distillation column 300. Both the first and third reboilers are equipped with condensate traps.

[0046] Control valves are installed on the following pipes: the first reboiler outlet pipe 114, the first reflux pipe 121, the dichlorosilane outlet pipe 122, the second reboiler outlet pipe 212, the second reflux pipe 231, the second feed pipe 232, the third reboiler outlet pipe 312, the third reflux pipe 321, the waste discharge pipe 322, the fourth reboiler outlet pipe 412, the fourth reflux pipe 421, and the trichlorosilane outlet pipe 422.

[0047] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An energy-efficient and high-performance chlorosilane separation system, characterized in that: The system includes a first distillation column (100), which is equipped with a first feed pipe (111), a first top outlet pipe (112), a side outlet pipe (113), and a first bottom outlet pipe (114). A first preheater (115) is installed on the first feed pipe (111). The first top outlet pipe (112) is connected to a second reboiler (220) and a first separator (120). The first separator (120) is equipped with a first reflux pipe (121) and a dichlorosilane outlet pipe (122). The first reflux pipe (121) is connected to the first distillation column (100), the first column bottom outlet pipe (114) is connected to the silicon tetrachloride outlet pipe through the first preheater (115), and the side outlet pipe (113) is connected to the second distillation column (200); the second distillation column (200) is provided with a second column top outlet pipe (211) and a second column bottom outlet pipe (212), the second column top outlet pipe (211) is connected to the second separator (230), and the second separator (230) is provided with a second reflux pipe (231) and the first column bottom outlet pipe (114). The second feed pipe (232) is connected to the second distillation column (200), and the second reflux pipe (231) is connected to the third distillation column (300). The third distillation column (300) is equipped with a third top outlet pipe (311) and a third bottom outlet pipe (312). The third top outlet pipe (311) is connected to the fourth reboiler (430) and the third separator (320). The third separator (320) is equipped with a third reflux pipe (321) and a waste discharge pipe (322). The flow pipe (321) is connected to the third distillation column (300), and the bottom outlet pipe (312) of the third column is connected to the fourth distillation column (400). The fourth distillation column (400) is provided with a fourth top outlet pipe (411) and a fourth bottom outlet pipe (412). The fourth top outlet pipe (411) is connected to the fourth separation tank (420). The fourth separation tank (420) is provided with a fourth reflux pipe (421) and a trichlorosilane outlet pipe (422). The fourth reflux pipe (421) is connected to the fourth distillation column (400).

2. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The first distillation column (100) is provided with a first pressure control unit (130), which includes a first pressure sensor (131) provided on the first distillation column (100), a first exhaust pipe (132) provided on the first separation tank (120), and a first pressure regulating valve (133) provided on the first exhaust pipe (132).

3. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The second distillation column (200) is provided with a second pressure control unit (240), which includes a second pressure sensor (241) provided on the second distillation column (200), a second exhaust pipe (242) provided on the second separation tank (230), and a second pressure regulating valve (243) provided on the second exhaust pipe (242).

4. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The third distillation column (300) is provided with a third pressure control unit (330), which includes a third pressure sensor (331) provided on the third distillation column (300), a third exhaust pipe (332) provided on the third separation tank (320), and a third pressure regulating valve (333) provided on the third exhaust pipe (332).

5. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The fourth distillation column (400) is provided with a fourth pressure control unit (440), which includes a fourth pressure sensor (441) provided on the fourth distillation column (400), a fourth exhaust pipe (442) provided on the fourth separation tank (420), and a fourth pressure regulating valve (443) provided on the fourth exhaust pipe (442).

6. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The first distillation column (100) is provided with a first temperature control unit (140), which includes a first temperature sensor (141) provided on the first distillation column (100), a first steam pipe (142) provided on the first reboiler, and a first steam regulating valve (143) on the first steam pipe (142).

7. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The third distillation column (300) is provided with a third temperature control unit (340), which includes a third temperature sensor (341) provided on the third distillation column (300), a third steam pipe (342) provided on the third reboiler, and a third steam regulating valve (343) on the third steam pipe (342).

8. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The first distillation column (100) is provided with a first liquid level control unit (150), which includes a first liquid level sensor (151) provided on the first distillation column (100) and a first reboiler discharge valve (152) provided on the first reboiler discharge pipe (114).

9. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The second distillation column (200) is provided with a second liquid level control unit (250), which includes a second liquid level sensor (251) provided on the second distillation column (200) and a second column bottom discharge valve (252) provided on the second column bottom discharge pipe (212).

10. The energy-saving and high-efficiency chlorosilane separation system according to claim 1, characterized in that: The fourth distillation column (400) is provided with a fourth liquid level control unit (450), which includes a fourth liquid level sensor (451) provided on the fourth distillation column (400) and a fourth column bottom discharge valve (452) provided on the fourth column bottom discharge pipe (412).

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