Particle silicon cold hydrogenation waste heat byproduct steam utilization system

Abstract

The utility model discloses a particle silicon cold hydrogenation waste heat byproduct steam utilization system which comprises a heat recovery heat exchanger which is configured to be capable of utilizing mixed gas containing hydrogen and chlorosilane to heat and vaporize condensate to obtain condensate steam, liquid-phase chlorosilane and gas-phase hydrogen; the heat recovery heat exchanger comprises a mixed gas inlet, a condensate inlet, a liquid outlet, an uncondensed gas outlet and a condensate steam outlet, the mixed gas inlet is used for receiving the mixed gas containing the hydrogen and the chlorosilane, the condensate inlet is used for receiving the condensate, the liquid outlet is used for allowing the liquid-phase chlorosilane to flow out, and the uncondensed gas outlet is used for allowing the liquid-phase chlorosilane to flow out. The uncondensed gas outlet is used for allowing the gas-phase hydrogen to flow out, and the condensate steam outlet is used for allowing the condensate steam to flow out to steam using equipment; the condensate storage device is used for storing condensate; and the condensate conveying pump is connected with the condensate storage device and the condensate inlet of the heat recovery heat exchanger.

Description

Technical Field

[0001] The utility model relates to the technical field of granular silicon cold hydrogenation, and in particular to a system for utilizing waste heat byproduct steam from granular silicon cold hydrogenation. Background Art

[0002] In the cold hydrogenation process, liquid chlorosilane containing silicon powder impurities is sent to the stripping tower, and the high-temperature hydrogen at the bottom of the stripping tower is used for mass transfer and heat exchange of the liquid chlorosilane containing silicon powder. The gaseous chlorosilane and hydrogen diffuse from the liquid chlorosilane. The high-temperature gaseous chlorosilane and hydrogen are cooled in sections by refrigerants such as Freon, ethylene glycol or circulating water, so that the chlorosilane and hydrogen are separated. The residual heat of the high-temperature gaseous chlorosilane is not used during the cooling process of the high-temperature gaseous chlorosilane to the liquid phase.

[0003] The above process consumes a large amount of refrigerant to separate the high-temperature hydrogen and chlorosilane gases, and the heat of the high-temperature chlorosilane and hydrogen is not utilized.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the utility model, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in this field. Utility Model Content

[0005] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a system for utilizing the waste heat by-product steam from the cold hydrogenation of granular silicon in view of the deficiencies in the prior art, which can separate the chlorosilane and hydrogen in a mixed gas containing hydrogen and chlorosilane, and can utilize the waste heat released during the separation.

[0006] In order to solve the above technical problems, the utility model discloses a system for utilizing waste heat by-product steam from cold hydrogenation of granular silicon, the system comprising:

[0007] A heat recovery heat exchanger is configured to heat the vaporized condensate with a mixed gas containing hydrogen and chlorosilane to obtain condensate steam, liquid chlorosilane and gaseous hydrogen. The heat recovery heat exchanger comprises a mixed gas inlet, a condensate inlet, a liquid outlet, an uncondensed gas outlet and a condensate steam outlet, wherein the mixed gas inlet is used to receive the mixed gas containing hydrogen and chlorosilane, the condensate inlet is used to receive the condensate, the liquid outlet is used to allow the liquid chlorosilane to flow out, the uncondensed gas outlet is used to allow the gaseous hydrogen to flow out, and the condensate steam outlet is used to allow the condensate steam to flow out to a steam-using device;

[0008] A condensate storage device, used for storing condensate;

[0009] and a condensate delivery pump, connecting the condensate storage device and the condensate inlet of the heat recovery heat exchanger, for pressurizing and delivering the condensate in the condensate storage device to the condensate inlet of the heat recovery heat exchanger.

[0010] In one embodiment, the device comprises a steam pipeline, and the condensate steam outlet is connected to the steam using equipment through the steam pipeline.

[0011] In one embodiment, the steam-using equipment is a silicon powder silo.

[0012] In one embodiment, the device includes a stripping tower, which is used to receive high-temperature hydrogen from a high-temperature hydrogen supply device and liquid chlorosilane containing impurities from a previous system, generate the purified mixed gas containing hydrogen and chlorosilane, and discharge the impurities. The stripping tower includes a first inlet, a second inlet, a first outlet, and a second outlet, the first inlet is used to receive high-temperature hydrogen, the second inlet is used to receive the liquid chlorosilane containing impurities, the first outlet is used to supply the mixed gas containing hydrogen and chlorosilane to flow out, and the second outlet is used to supply the impurities to be discharged. The first outlet of the stripping tower is connected to the mixed gas inlet of the heat recovery heat exchanger.

[0013] In one embodiment, the high-temperature hydrogen supply device includes a hydrogen supply device and a hydrogen heater, the outlet of the hydrogen supply device is connected to the inlet of the hydrogen heater, and the outlet of the hydrogen heater is connected to the first inlet of the stripping tower for providing the high-temperature hydrogen to the stripping tower.

[0014] In one embodiment, the device comprises a miscellaneous material processing device, which is connected to the second outlet of the stripping tower and is used to process the miscellaneous materials discharged from the stripping tower.

[0015] In one embodiment, the device comprises a stripping tower reflux tank and a stripping tower reflux pump, wherein the stripping tower reflux tank comprises a liquid-phase chlorosilane inlet and a liquid-phase chlorosilane outlet, wherein the liquid-phase chlorosilane inlet of the stripping tower reflux tank is connected to the liquid outlet of the heat recovery heat exchanger, and is used to receive and store the liquid-phase chlorosilane from the liquid outlet of the heat recovery heat exchanger. The inlet of the stripping tower reflux pump is connected to the liquid-phase chlorosilane outlet of the stripping tower reflux tank, and the outlet of the stripping tower reflux pump is connected to the top reflux port of the stripping tower, and is used to provide the liquid-phase chlorosilane in the stripping tower reflux tank to the top of the stripping tower.

[0016] In one embodiment, the device comprises a hydrogen pipeline and a hydrogen-using device, wherein the hydrogen pipeline connects the uncondensed gas outlet of the heat recovery heat exchanger and the hydrogen-using device.

[0017] In one embodiment, the device further includes a first temperature sensor, which is disposed at the outlet of the hydrogen heater and is used to detect the temperature of the high-temperature hydrogen after being heated by the hydrogen heater.

[0018] In one embodiment, the device further comprises a second temperature sensor and a third temperature sensor, wherein the second temperature sensor is arranged at the condensate steam outlet of the heat recovery heat exchanger, and the third temperature sensor is arranged at the first outlet of the stripping tower to measure the temperature of the mixed gas containing hydrogen and chlorosilane discharged from the stripping tower.

[0019] Beneficial effects:

[0020] The utility model uses a heat recovery heat exchanger to exchange heat between the high-temperature mixed gas containing hydrogen and chlorosilane separated at the top of the stripping tower and the condensate. Compared with the prior art that uses a refrigerant for heat exchange, the utility model uses the condensate, which can achieve the function of separating hydrogen and chlorosilane, save the cost of using the refrigerant, and can recover the waste heat and by-product steam for heating the silicon powder silo or entering the steam pipeline for heating other equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, and the above and / or other advantages of the present invention will become more clear.

[0022] Figure 1 A schematic structural diagram of a system for utilizing waste heat by-product steam from cold hydrogenation of granular silicon provided in one embodiment of the utility model.

[0023] The description of the accompanying drawings is:

[0024] 1. Hydrogen electric heater; 2. Stripping tower; 21. First inlet; 22. Second inlet; 23. First outlet; 24. Second outlet; 25. Top reflux port; 3. Heat exchanger; 31. Mixed gas inlet; 32. Condensate inlet; 33. Liquid outlet; 34. Uncondensed gas outlet; 35. Condensate steam outlet; 4. Stripping tower reflux pump; 5. Condensate delivery pump; 6. Condensate storage tank; 7. Stripping tower reflux tank; 71. Liquid chlorosilane inlet; 72. Liquid chlorosilane outlet; 8. Silicon powder silo; 9. Front system; 10. Hydrogen supply device; 11. Steam pipeline; 12. Hydrogen pipeline; 13. Miscellaneous material processing device. T1. First temperature sensor; T2. Second temperature sensor; T3. Third temperature sensor. DETAILED DESCRIPTION

[0025] See now Figure 1 The utility model provides a system for utilizing waste heat by-product steam from cold hydrogenation of granular silicon. The system includes a heat recovery heat exchanger 3, a condensate storage device 6 and a condensate delivery pump 5.

[0026] The heat recovery heat exchanger 3 is configured to heat the vaporized condensate with the mixed gas containing hydrogen and chlorosilane to obtain condensate steam, liquid chlorosilane and gaseous hydrogen. The heat recovery heat exchanger 3 includes a mixed gas inlet 31, a condensate inlet 32, a liquid outlet 33, an uncondensed gas outlet 34 and a condensate steam outlet 35. The mixed gas inlet 31 is used to receive the mixed gas containing hydrogen and chlorosilane, the condensate inlet 32 ​​is used to receive the condensate, the liquid outlet 33 is used to supply the liquid chlorosilane to flow out, the uncondensed gas outlet 34 is used to supply the gaseous hydrogen to flow out, and the condensate steam outlet 35 is used to supply the condensate steam to flow out to the steam using equipment.

[0027] The condensate storage device 6 is used to store the condensate.

[0028] The condensate delivery pump connects the condensate storage device and the condensate inlet of the heat recovery heat exchanger, and is used for pressurizing and delivering the condensate in the condensate storage device to the condensate inlet of the heat recovery heat exchanger.

[0029] In one embodiment, now see Figure 1 The device includes a steam pipeline 11, and the condensate steam outlet 35 is connected to the steam using equipment through the steam pipeline 11.

[0030] In one embodiment, the steam-using device is a silicon powder silo.

[0031] In one embodiment, now see Figure 1 The device includes a stripping tower 2, which is used to receive high-temperature hydrogen from a high-temperature hydrogen supply device and liquid chlorosilane containing impurities from a front system 9, generate a purified mixed gas containing hydrogen and chlorosilane and discharge the impurities; the stripping tower 2 includes a first inlet 21, a second inlet 22, a first outlet 23 and a second outlet 24, the first inlet 21 is used to receive high-temperature hydrogen, the second inlet 22 is used to receive liquid chlorosilane containing impurities, the first outlet 23 is used to supply the mixed gas containing hydrogen and chlorosilane to flow out, and the second outlet 24 is used to discharge the impurities; the first outlet 23 of the stripping tower 2 is connected to the mixed gas inlet 31 of the heat recovery heat exchanger 3.

[0032] In one embodiment, now see Figure 1 The high-temperature hydrogen supply device includes a hydrogen supply device 10 and a hydrogen heater 1. The outlet of the hydrogen supply device 10 is connected to the inlet of the hydrogen heater 1. The outlet of the hydrogen heater 1 is connected to the first inlet 21 of the stripping tower 2 for providing high-temperature hydrogen to the stripping tower 2.

[0033] In one embodiment, now see Figure 1 The device also includes a first temperature sensor T1, which is arranged at the outlet of the hydrogen heater 1 and is used to detect the temperature of the high-temperature hydrogen heated by the hydrogen heater 1.

[0034] In one embodiment, now see Figure 1 The device includes a miscellaneous material processing device 13, which is connected to the second outlet 24 of the stripping tower 2 and is used to process the miscellaneous materials discharged from the stripping tower 2.

[0035] In one embodiment, now see Figure 1 The device includes a stripping tower reflux tank 7 and a stripping tower reflux pump 4. The stripping tower reflux tank 7 includes a liquid-phase chlorosilane inlet 71 and a liquid-phase chlorosilane outlet 72. The liquid-phase chlorosilane inlet 71 of the stripping tower reflux tank 7 is connected to the liquid outlet 33 of the heat recovery heat exchanger 3, and is used to receive and store liquid-phase chlorosilane from the heat recovery heat exchanger 3; the inlet of the stripping tower reflux pump 4 is connected to the liquid-phase chlorosilane outlet 72 of the stripping tower reflux tank 7, and the outlet of the stripping tower reflux pump 4 is connected to the top reflux port 25 of the stripping tower 2, and is used to provide the liquid-phase chlorosilane in the stripping tower reflux tank 7 to the top of the stripping tower 2 for washing and cooling.

[0036] In one embodiment, now see Figure 1 The device includes a hydrogen pipeline 12 and a hydrogen-using device. The hydrogen pipeline 12 connects the uncondensed gas outlet 34 of the heat recovery heat exchanger 3 and the hydrogen-using device.

[0037] In one embodiment, now see Figure 1 The device includes a second temperature sensor T2 and a third temperature sensor T3. The second temperature sensor T2 is arranged at the condensate steam outlet 35 of the heat recovery heat exchanger 3 to measure the temperature of the gas phase hydrogen. The third temperature sensor T3 is arranged at the first outlet 23 of the stripping tower 2 to measure the temperature of the mixed gas containing hydrogen and chlorosilane discharged from the stripping tower 2.

[0038] Below, refer to Figure 1 , the working process of the granular silicon cold hydrogenation waste heat by-product steam utilization system of the utility model is explained.

[0039] The front system 9 produces liquid chlorosilane containing impurities such as silicon powder. The hydrogen supplied by the hydrogen supply device 10 is heated by the hydrogen heater 1 to form high-temperature hydrogen. The stripping tower 2 receives the high-temperature hydrogen from the high-temperature hydrogen supply device and the liquid chlorosilane containing impurities from the front system 9, produces a purified mixed gas containing hydrogen and chlorosilane, and discharges the impurities regularly. The impurity processing device 13 processes the impurities discharged from the stripping tower 2.

[0040] The mixed gas containing hydrogen and chlorosilane diffuses out from the top of the stripping tower 2 and enters the tube side of the heat recovery heat exchanger 3. The condensate delivery pump 5 pressurizes and delivers the condensate in the condensate storage device 6 to the heat recovery heat exchanger 3. The heat recovery heat exchanger 3 uses the mixed gas containing hydrogen and chlorosilane to heat and vaporize the condensate to obtain condensate vapor, liquid chlorosilane and gaseous hydrogen.

[0041] The stripping tower reflux tank 7 receives and stores the liquid chlorosilane from the liquid outlet 33 of the heat recovery heat exchanger 3. The stripping tower reflux pump 4 provides the liquid chlorosilane in the stripping tower reflux tank 7 to the top of the stripping tower 2 for washing and cooling.

[0042] The gaseous hydrogen flows out from the uncondensed gas outlet 34 of the heat recovery heat exchanger 3 to the hydrogen pipeline 12 for use by hydrogen-using equipment.

[0043] The condensate steam flows out from the condensate steam outlet 35 of the heat recovery heat exchanger 3 to the steam pipeline 11 to be used for heating the steam-using equipment.

[0044] The utility model provides a system for utilizing the waste heat and byproduct steam of granular silicon cold hydrogenation. There are many methods and ways to implement the technical solution. The above is only the preferred implementation of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the protection scope of the utility model. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon, characterized in that: include: The heat recovery heat exchanger (3) is configured to heat the vaporized condensate using a mixed gas containing hydrogen and chlorosilane to obtain condensate steam, liquid chlorosilane and gaseous hydrogen; the heat recovery heat exchanger (3) comprises a mixed gas inlet (31), a condensate inlet (32), a liquid outlet (33), an uncondensed gas outlet (34) and a condensate steam outlet (35); the mixed gas inlet (31) is used to receive the mixed gas containing hydrogen and chlorosilane, the condensate inlet (32) is used to receive the condensate, the liquid outlet (33) is used to allow the liquid chlorosilane to flow out, the uncondensed gas outlet (34) is used to allow the gaseous hydrogen to flow out, and the condensate steam outlet (35) is used to allow the condensate steam to flow out to a steam-using device; A condensate storage device (6), used for storing the condensate; and a condensate delivery pump (5), which connects the condensate storage device (6) and the condensate inlet (32) of the heat recovery heat exchanger (3), and is used to pressurize and deliver the condensate in the condensate storage device (6) to the condensate inlet (32) of the heat recovery heat exchanger (3).

2. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 1, characterized in that: It comprises a steam pipeline (11), and the condensate steam outlet (35) is connected to the steam using equipment through the steam pipeline (11).

3. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 2, characterized in that: The steam using equipment is a silicon powder silo.

4. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 1, characterized in that: The invention comprises a stripping tower (2), wherein the stripping tower (2) is used to receive high-temperature hydrogen from a high-temperature hydrogen supply device and liquid-phase chlorosilane containing impurities from a front system (9), generate a purified mixed gas containing hydrogen and chlorosilane, and discharge the impurities; the stripping tower (2) comprises a first inlet (21), a second inlet (22), a first outlet (23), and a second outlet (24), wherein the first inlet (21) is used to receive high-temperature hydrogen, the second inlet (22) is used to receive the liquid-phase chlorosilane containing impurities, the first outlet (23) is used to supply the mixed gas containing hydrogen and chlorosilane to flow out, and the second outlet (24) is used to supply the impurities to be discharged; the first outlet (23) of the stripping tower (2) is connected to the mixed gas inlet (31) of the heat recovery heat exchanger (3).

5. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 4, characterized in that: The high-temperature hydrogen supply device comprises a hydrogen supply device (10) and a hydrogen heater (1), wherein the outlet of the hydrogen supply device (10) is connected to the inlet of the hydrogen heater (1), and the outlet of the hydrogen heater (1) is connected to the first inlet (21) of the stripping tower (2), so as to provide the high-temperature hydrogen to the stripping tower (2).

6. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 5, characterized in that: It also includes a first temperature sensor (T1), which is arranged at the outlet of the hydrogen heater (1).

7. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 4, characterized in that: It comprises a miscellaneous material processing device (13), which is connected to the second outlet (24) of the stripping tower (2) and is used to process the miscellaneous materials discharged from the stripping tower (2).

8. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 4, characterized in that: The invention comprises a stripping tower reflux tank (7) and a stripping tower reflux pump (4), wherein the stripping tower reflux tank (7) comprises a liquid-phase chlorosilane inlet (71) and a liquid-phase chlorosilane outlet (72), wherein the liquid-phase chlorosilane inlet (71) of the stripping tower reflux tank (7) is connected to a liquid outlet (33) of the heat recovery heat exchanger (3), and is used for receiving and storing the liquid-phase chlorosilane from the heat recovery heat exchanger (3); the inlet of the stripping tower reflux pump (4) is connected to the liquid-phase chlorosilane outlet (72) of the stripping tower reflux tank (7), and the outlet of the stripping tower reflux pump (4) is connected to a top reflux port (25) of the stripping tower (2).

9. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 1, characterized in that: It comprises a hydrogen pipeline (12) and a hydrogen-using device, wherein the hydrogen pipeline (12) connects the uncondensed gas outlet (34) of the heat recovery heat exchanger (3) and the hydrogen-using device.

10. The system for utilizing waste heat and by-product steam from cold hydrogenation of granular silicon according to claim 4, characterized in that: It comprises a second temperature sensor (T2) and a third temperature sensor (T3), wherein the second temperature sensor (T2) is arranged at the condensate steam outlet (35) of the heat recovery heat exchanger (3); and the third temperature sensor (T3) is arranged at the first outlet (23) of the stripping tower (2).

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