Chlorosilane regeneration system

Abstract

The utility model discloses a chlorosilane regeneration system which comprises a reactor used for containing silicon waste materials; the reactor is supplied with hydrogen chloride gas, and the hydrogen chloride gas reacts with the silicon waste to obtain a mixed gas of chlorosilane gas, hydrogen and hydrogen chloride gas; the cooling device is connected with the reactor; the cooling device is used for cooling the mixed gas; the condensation cooling device is connected with the cooling device; the condensation cooling device is used for condensing and cooling the mixed gas into a gas-liquid two-phase fluid, wherein the liquid phase is chlorosilane gas in the mixed gas; the gas-liquid separation device is connected with the condensation cooling device; the gas-liquid separation device is used for separating the liquid-phase chlorosilane from the gas-phase fluid and the liquid-phase fluid; the rectification device is connected with the gas-liquid separation device; and the rectification device is used for rectifying and purifying the liquid-phase chlorosilane.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of chlorosilane regeneration, specifically relates to a chlorosilane regeneration system. BACKGROUND

[0002] The phenomenon of a large amount of silicon adhering to the bearing part occurs in the production process of granular silicon, thereby seriously affecting the use performance of the bearing part; the production process of granular silicon is accompanied by the generation of silicon blocks that cannot be used or have low added value.

[0003] In the prior art, the bearing part with a large amount of silicon adhering thereto is usually directly discarded, which is not conducive to cost reduction.

[0004] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the utility model and should not be regarded as an acknowledgment or any form of suggestion that this information forms prior art that is publicly known. SUMMARY

[0005] The utility model relates to the technical field of chlorosilane regeneration, specifically relates to a chlorosilane regeneration system.

[0006] In order to solve the above technical problems, the utility model discloses a chlorosilane regeneration system, which comprises:

[0007] A reactor is used for containing silicon waste; the reactor is supplied with hydrogen chloride gas, the hydrogen chloride gas reacts with the silicon waste, and chlorosilane gas, hydrogen gas and hydrogen chloride gas mixed gas are obtained;

[0008] A cooling device is connected with the reactor; the cooling device is used for cooling the mixed gas;

[0009] A condensing device is connected with the cooling device; the condensing device is used for condensing the mixed gas into gas-liquid two-phase fluid, wherein the liquid phase is chlorosilane gas in the mixed gas;

[0010] A gas-liquid separation device is connected with the condensing device; the gas-liquid separation device is used for separating the liquid phase chlorosilane from the gas-liquid two-phase fluid;

[0011] And a rectifying device is connected with the gas-liquid separation device; the rectifying device is used for rectifying and purifying the liquid phase chlorosilane.

[0012] Further, the system further comprises a filtering device, the filtering device is arranged on the pipeline connecting the condensing device and the gas-liquid separation device; the filtering device is used for removing the particulate solid impurities entrained in the mixed gas.

[0013] Further, the system further comprises a preheating device for preheating the hydrogen chloride gas, and an outlet of the preheating device is connected with the side inlet of the reactor.

[0014] Specifically, the preheating device is a gas-gas heat exchanger, which comprises a low-temperature gas passage and a high-temperature gas passage, and an inlet of the low-temperature gas passage is connected with an external hydrogen chloride gas source. An outlet of the low-temperature gas passage is connected with the side inlet of the reactor as an outlet of the preheating device. An inlet of the high-temperature gas passage is connected with the top outlet of the reactor, and an outlet of the high-temperature gas passage is connected with an inlet of the cooling device.

[0015] Specifically, the mixed gas from the reactor enters the high-temperature gas passage of the gas-gas heat exchanger, and then enters the cooling device. The hydrogen chloride gas enters the low-temperature gas passage of the gas-gas heat exchanger, exchanges heat with the mixed gas in the high-temperature gas passage, and then enters the reactor.

[0016] Specifically, the reactor is provided with two or more reactors. Inlets of the two or more reactors are connected in parallel with the outlet of the low-temperature gas passage of the gas-gas heat exchanger, and outlets of the two or more reactors are connected in parallel with the inlet of the high-temperature gas passage of the gas-gas heat exchanger.

[0017] Specifically, the cooling device is a circulating water heat exchanger, which is used for cooling the mixed gas by circulating water.

[0018] Specifically, the reactor is a reactor provided with an electric heater, which is used for providing heat required for the reaction of the hydrogen chloride gas and the silicon waste.

[0019] Specifically, the system comprises a delivery pump, which is installed on a pipeline connecting the rectification device and the gas-liquid separation device.

[0020] Further, the system further comprises a waste gas treatment device, and a top tail gas outlet of the gas-liquid separation device is connected with the waste gas treatment device.

[0021] Beneficial effects:

[0022] 1. The chlorosilane regeneration system of the present application can remove the attached silicon on the bearing part in the production of granular silicon, thereby prolonging the service life of the bearing part.

[0023] 2. The present application can reduce the waste of waste silicon blocks by filling the waste silicon blocks and other silicon materials in the reactor to react with hydrogen chloride gas, and then cooling, removing impurities, condensing and separating, and rectifying and purifying to obtain liquid phase chlorosilane. The liquid phase chlorosilane after rectification and purification can be used for the production of granular silicon.

[0024] 3. The recovered chlorosilane can supplement the chlorosilane lost in the production system to a certain extent, and is used for producing granular silicon.

[0025] 4. One embodiment of the present application uses the waste heat of the mixed gas generated by the reaction to heat the hydrogen chloride gas to be supplied to the reactor through a gas-gas heat exchanger, while preliminarily reducing the temperature of the mixed gas. By recycling the waste heat of the mixed gas generated by the reaction, the energy utilization rate is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or other aspects of the present application will become more apparent by describing in detail the preferred embodiments thereof with reference to the attached drawings in which:

[0027] Figure 1 The structure diagram of the chlorosilane regeneration system provided for one embodiment of the present application is shown.

[0028] The reference signs are as follows: 10, gas-gas heat exchanger; 11, hydrogen chloride gas source; 20, cooling device; 30, reactor; 31, side gas inlet; 32, top gas outlet; 40, filtering device; 50, condensing cooling device; 60, gas-liquid separation device; 70, rectification device; 80, conveying pump; 90, waste gas treatment device. DETAILED DESCRIPTION

[0029] In the production process of granular silicon, a large amount of silicon is attached to the carrier, thereby seriously affecting the performance of the carrier. In addition, in the production process of granular silicon, silicon blocks that cannot be used or have low added value are also generated. In the present application, the silicon attached to the carrier in the production process of granular silicon and the silicon blocks that cannot be used or have low added value generated in the production process of granular silicon are collectively referred to as silicon waste.

[0030] The present application provides a chlorosilane regeneration system, which is shown in Figure 1 The system comprises a reactor 30, a cooling device 20, a condensing cooling device 50, a gas-liquid separation device 60, and a rectification device 70.

[0031] The reactor 30 is used to accommodate the silicon waste. The reactor 30 is supplied with hydrogen chloride gas, and the hydrogen chloride gas reacts with the silicon waste to obtain chlorosilane gas, hydrogen gas, and hydrogen chloride gas mixed gas.

[0032] The cooling device 20 is connected with the reactor 30. The cooling device 20 is used to cool and reduce the temperature of the mixed gas.

[0033] The condensing cooling device 50 is connected with the cooling cooling device 20. The condensing cooling device 50 is used for condensing and cooling the mixed gas into a gas-liquid two-phase fluid, wherein the liquid phase is chlorosilane gas in the mixed gas.

[0034] The gas-liquid separation device 60 is connected with the condensing cooling device 50. The gas-liquid separation device 60 is used for separating the liquid phase chlorosilane from the gas-liquid two-phase fluid.

[0035] The rectifying device 70 is connected with the gas-liquid separation device 60. The rectifying device 70 is used for rectifying and purifying the liquid phase chlorosilane.

[0036] The working principle of the utility model is as follows: the particle silicon production process is put into the reactor 30, and the hydrogen chloride gas is introduced into the reactor 30. The reactor 30 is heated by the electric heater, so that the hydrogen chloride gas reacts with the silicon waste, and the chlorosilane gas, hydrogen and hydrogen chloride gas mixture are obtained, and the chemical reaction formula is 3Si+10HCl=SiCl4+2SiHCl3+4H2. The mixed gas is cooled by the cooling cooling device 20, and then flows into the condensing cooling device 50. The condensing cooling device 50 condenses and cools the mixed gas into a gas-liquid two-phase fluid, wherein the liquid phase is chlorosilane gas in the mixed gas. The gas-liquid two-phase fluid flows into the gas-liquid separation device 60, and the gas-liquid separation device 60 separates the liquid phase chlorosilane from the gas-liquid two-phase fluid. The liquid phase chlorosilane is sent to the rectifying device 70, and the rectifying device 70 rectifies and purifies the liquid phase chlorosilane.

[0037] In some embodiments, referring to Figure 1 The side of the rectifying device 70 is connected with the chlorosilane conveying pipeline 71, and the rectified chlorosilane is conveyed to the particle silicon production device by the chlorosilane conveying pipeline 71 to participate in production again, so that the low-value-added silicon is collected, and the cost is effectively reduced.

[0038] Specifically, the condensing cooling device 50 adopts a pipeline heat exchanger.

[0039] Specifically, the rectifying device 70 is a rectifying tower.

[0040] Specifically, referring to Figure 1 The reactor 30 is provided with a side gas inlet 31 for introducing hydrogen chloride gas into the reactor 30 and a top gas outlet 32 for discharging the mixed gas generated by reaction.

[0041] In some embodiments, referring to Figure 1 The system further comprises a filtering device 40 arranged on the pipeline connecting the condensing cooling device 50 and the gas-liquid separation device 60. The filtering device 40 is used for removing the particulate solid impurities entrained in the mixed gas.

[0042] In some embodiments, the system further comprises a preheating device for preheating the hydrogen chloride gas, and the gas outlet of the preheating device is connected to the side gas inlet 31 of the reactor 30.

[0043] Specifically, referring to Figure 1 , the preheating device is a gas-gas heat exchanger 10, which comprises a low-temperature gas passage and a high-temperature gas passage. The gas inlet of the low-temperature gas passage is used to connect to the external hydrogen chloride gas source 11. The gas outlet of the low-temperature gas passage, as the gas outlet of the preheating device, is connected to the side gas inlet 31 of the reactor 30. The gas inlet of the high-temperature gas passage is connected to the top gas outlet 32 of the reactor 30, and the gas outlet of the high-temperature gas passage is connected to the gas inlet of the cooling device 20.

[0044] In this application, the gas-gas heat exchanger 10 is arranged to heat the hydrogen chloride gas to be supplied to the reactor by using the waste heat of the mixed gas generated by the reaction, while preliminarily reducing the temperature of the mixed gas. By recycling the waste heat of the mixed gas generated by the reaction, the energy utilization rate is improved.

[0045] Specifically, the mixed gas from the reactor 30 enters the high-temperature gas passage of the gas-gas heat exchanger 10, and then enters the condensing cooling device 50 through the high-temperature gas passage. The hydrogen chloride gas enters the low-temperature gas passage of the gas-gas heat exchanger 10 and is heated by exchanging heat with the mixed gas in the high-temperature gas passage, and then enters the reactor 30.

[0046] Specifically, referring to Figure 1 , the reactor 30 is provided with two or more. The gas inlets of the two or more reactors 30 are connected in parallel to the gas outlet of the low-temperature gas passage in the gas-gas heat exchanger 10, and the gas outlets of the two or more reactors 30 are connected in parallel to the gas inlet of the high-temperature gas passage in the gas-gas heat exchanger 10.

[0047] Specifically, the cooling device 20 is a circulating water heat exchanger, which is used to cool the mixed gas by using circulating water. The circulating water is more environmentally friendly than other heat exchange media.

[0048] Specifically, the reactor 30 is a reactor with an electric heater, which is used to provide the heat required for the reaction of hydrogen chloride gas and silicon waste.

[0049] Specifically, referring to Figure 1 , the system comprises a delivery pump 80 installed on the pipeline connecting the rectification device 70 and the gas-liquid separation device 60. Specifically, when the liquid level of the liquid phase in the gas-liquid separation device 60 reaches a certain level, the delivery pump 80 is started to send the chlorosilane in the liquid phase into the rectification device 70 from the side.

[0050] In some embodiments, the system further comprises a waste gas treatment device, and the top tail gas outlet of the gas-liquid separation device 60 is connected with the waste gas treatment device.

[0051] The utility model provides a kind of chlorosilane regeneration system's train of thought and method, the method and approach of specifically realizing this technical scheme are many, above-mentioned is only the preferred embodiment of the utility model, it should be pointed out, for the ordinary skilled person in the art, without departing from the principle of the utility model, still can make several improvements and refinements, these improvements and refinements also should be regarded as the protection range of the utility model.The components not specified in the embodiment can be implemented using existing technology.

Claims

1. A chlorosilane regeneration system characterized by, The application relates to a device for producing chlorosilane from silicon waste. The device comprises: a reactor (30) for containing silicon waste; the reactor (30) is supplied with hydrogen chloride gas, which reacts with the silicon waste to obtain a mixed gas of chlorosilane gas, hydrogen and hydrogen chloride gas; a cooling device (20) connected to the reactor (30); the cooling device (20) is used for cooling the mixed gas; a condensing device (50) connected to the cooling device (20); the condensing device (50) is used for condensing the mixed gas into a gas-liquid two-phase fluid, wherein the liquid phase is the chlorosilane gas in the mixed gas; a gas-liquid separation device (60) connected to the condensing device (50); the gas-liquid separation device (60) is used for separating the liquid phase chlorosilane from the gas-liquid two-phase fluid; and 2. The chlorosilane regeneration system of claim 1, wherein, a rectifying device (70) connected to the gas-liquid separation device (60); the rectifying device (70) is used for rectifying and purifying the liquid phase chlorosilane.

3. The chlorosilane regeneration system of claim 1, wherein, The device further comprises a filtering device (40) arranged on a pipeline connecting the condensing device (50) and the gas-liquid separation device (60); the filtering device (40) is used for removing particulate solid impurities entrained in the mixed gas.

4. The chlorosilane regeneration system of claim 3, wherein, The device further comprises a preheating device for preheating hydrogen chloride gas; the gas outlet of the preheating device is connected to the side gas inlet of the reactor (30).

5. The chlorosilane regeneration system of claim 4, wherein, The preheating device is a gas-gas heat exchanger (10); the gas-gas heat exchanger (10) comprises a low-temperature gas passage and a high-temperature gas passage; the gas inlet of the low-temperature gas passage is used for being connected to an external hydrogen chloride gas source (11); the gas outlet of the low-temperature gas passage serves as the gas outlet of the preheating device and is connected to the side gas inlet (31) of the reactor (30); the gas inlet of the high-temperature gas passage is connected to the top gas outlet (32) of the reactor (30); and the gas outlet of the high-temperature gas passage is connected to the gas inlet of the cooling device (20).

6. The chlorosilane regeneration system of claim 4, wherein, The mixed gas from the reactor (30) enters the high-temperature gas passage of the gas-gas heat exchanger (10) and then enters the condensing device (50) through the high-temperature gas passage; the hydrogen chloride gas enters the low-temperature gas passage of the gas-gas heat exchanger (10) and is heated by exchanging heat with the mixed gas in the high-temperature gas passage and then enters the reactor (30).

7. The chlorosilane regeneration system of claim 1, wherein, The reactor (30) is provided with two or more reactors; the gas inlets of the two or more reactors are connected in parallel to the gas outlet of the low-temperature gas passage in the gas-gas heat exchanger (10); and the gas outlets of the two or more reactors are connected in parallel to the gas inlet of the high-temperature gas passage in the gas-gas heat exchanger (10).

8. The chlorosilane regeneration system of claim 1, wherein, The cooling device (20) is a circulating water heat exchanger; the circulating water heat exchanger is used for cooling the mixed gas by using circulating water. The reactor (30) is a reactor provided with an electric heater; the electric heater is used for providing heat required for the reaction of the hydrogen chloride gas and the silicon waste.

9. The chlorosilane regeneration system of claim 1, wherein, A delivery pump (80) is included, which is installed on a pipeline connecting the rectification device (70) and the gas-liquid separation device (60).

10. The chlorosilane regeneration system of claim 1, wherein, An exhaust gas treatment device (90) is also included, and a top tail gas outlet of the gas-liquid separation device (60) is connected with the exhaust gas treatment device (90).

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