Cold hydrogenation product treatment system and polycrystalline silicon production system
The cold hydrogenation product processing system, which incorporates a dual coarse separation tower design and waste heat cascade recovery, solves the problem of high equipment load in polysilicon production, achieves efficient separation and waste heat recovery, and reduces failure rate and production costs.
Patent Information
- Application Number
- CN202423243672.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-12-27
AI Technical Summary
In existing polysilicon production systems, the coarse grading tower equipment has a high load, resulting in high production costs and a high failure rate, making it difficult to meet the needs of large-scale production.
The cold hydrogenation product processing system adopts a dual coarse separation tower design and a waste heat cascade recovery system. Through the coupling of the first and second coarse separation towers, combined with washing and dust removal, condensation, distillation and vaporization devices, it achieves efficient separation and waste heat recovery.
It reduced the system load, improved the operating efficiency and energy utilization of the equipment, reduced the failure rate, and reduced the load and cost of slurry treatment.
Smart Images
Figure CN223668677U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of polysilicon production, in particular to a cold hydrogenation product processing system and a polysilicon production system. BACKGROUND
[0002] The improved Siemens method is a widely used method for preparing high-purity polysilicon, and the cold hydrogenation process is one of the key steps. In the cold hydrogenation fluidized bed reactor, a specific proportion of silicon tetrachloride, hydrogen and silicon powder react under the action of a catalyst under the required pressure and temperature conditions to generate trichlorosilane. The mixed gas discharged from the reactor is subjected to washing, quenching, wet dust removal cooling, condensation and other steps, and the unreacted hydrogen and silicon tetrachloride are returned to the reactor through a recovery device to participate in the reaction again and be recycled. Since the silicon powder contains a small amount of metal impurities, the product produced by the reactor will contain a small amount of metal chlorides, catalysts and silicon powder impurities. After these impurities are concentrated by wet dust removal, they are sent to a slag slurry recovery device for treatment.
[0003] In the prior art, when the cold hydrogenation product is separated, the reaction product is used as raw material to enter the rough separation tower, the rough separation tower separates the silicon tetrachloride in the material from the tower kettle, the non-condensable gas is discharged from the top of the tower, and the trichlorosilane and dichlorosilane are taken out from the top of the tower to enter the subsequent rectification. The unreacted silicon powder is discharged to the slag slurry treatment process for treatment. Generally, the rough separation tower is a single separation tower. As the production scale of the polysilicon plant becomes larger and larger, the production capacity of a single production line also becomes higher and higher, and the equipment of the rough separation tower also becomes larger and larger, which also causes the load of the designed system to become larger and larger. Not only the production cost is high, but also the equipment failure is increased. CONTENT OF THE UTILITY MODEL
[0004] The cold hydrogenation product processing system and the polysilicon production system provided by the embodiments of the present application can reduce the system load, realize higher efficiency and lower failure rate with smaller equipment and facilities.
[0005] The embodiments of the present application are implemented as follows:
[0006] In a first aspect, the present application provides a cold hydrogenation product processing system, comprising: a washing and dust removal system and a separation system, the washing and dust removal system is used for receiving cold hydrogenation products and removing impurities from the cold hydrogenation products;
[0007] The separation system comprises a first rough separation tower, a second rough separation tower, a first rough separation tower reboiler, a second rough separation tower reboiler, a rectification device, a condensation device and a vaporization device; the gas outlet of the washing and dust removal system is communicated with the first rough separation tower reboiler, the first rough separation tower reboiler is communicated with the condensation device, the gas outlet of the condensation device is communicated with the first rough separation tower and the second rough separation tower, the first rough separation tower is communicated with the rectification device; the second rough separation tower is communicated with the second rough separation tower reboiler, the second rough separation tower reboiler is communicated with the rectification device; the discharge outlets of the first rough separation tower and the second rough separation tower are both communicated with the vaporization device.
[0008] In a possible implementation, the outlet of the second rough separation tower reboiler is communicated with the side inlet of the second rough separation tower.
[0009] In a possible implementation, the first rough separation tower reboiler and the second rough separation tower reboiler are arranged in parallel and used for providing heat for the first rough separation tower.
[0010] In a possible implementation, the washing and dust removal system is communicated with a slurry device for supplying the washed silicon tetrachloride into the slurry device.
[0011] In a possible implementation, a hydrogen supply pipeline and a silicon tetrachloride supply pipeline communicated with the vaporization device are further included, the hydrogen supply pipeline and the silicon tetrachloride supply pipeline are respectively used for supplying hydrogen and silicon tetrachloride into the vaporization device.
[0012] In a possible implementation, the top of the first rough separation tower is directly communicated with the rectification device through a tapping pipeline.
[0013] In a possible implementation, the first rough separation tower is directly communicated with the rectification device through a tapping pipeline.
[0014] In a possible implementation, a trichlorosilane synthesis furnace is further included, the cyclone separator has a first powder outlet, the first powder outlet is communicated with an inlet of the trichlorosilane synthesis furnace, so that the silicon powder separated by the cyclone separator can enter the trichlorosilane synthesis furnace to react with HCL.
[0015] In a possible implementation, the cyclone separator further has a second powder outlet, the second powder outlet is communicated with the cold hydrogenation reactor to supply the silicon powder to the cold hydrogenation reactor.
[0016] In a possible implementation, a synthesis gas treatment device is further included, an outlet of the trichlorosilane synthesis furnace is communicated with the synthesis gas treatment device.
[0017] The application has at least the following beneficial effects:
[0018] The cold hydrogenation product treatment system of the application passes the gas phase after washing and dust removal of the cold hydrogenation product into the first rough separation tower reboiler for heat exchange, and the gas phase after waste heat recovery is passed into the condensing device for condensation, and then the material is divided into two paths from the condensing device and enters the first rough separation tower and the second rough separation tower. The first rough separation tower and the second rough separation tower can separate silicon tetrachloride, the light component separated by the first rough separation tower is passed into the rectifying device for rectification treatment, and the light component separated by the second rough separation tower is first passed through the second rough separation tower reboiler coupled with waste heat utilization and then passed into the rectifying device for rectification treatment. The silicon tetrachloride separated by the first rough separation tower and the second rough separation tower is passed into the vaporization device for vaporization, and can be used for preparation of the cold hydrogenation product. The cold hydrogenation product treatment system of the application can reduce system load, realize higher efficiency and lower failure rate with smaller equipment and facilities through the coupled design of the first rough separation tower and the second rough separation tower and the stepwise recovery and utilization of waste heat. In addition, the energy utilization rate is also improved through heat coupling utilization. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.
[0020] Figure 1 A schematic diagram of a polysilicon production system of the application.
[0021] Icon: 10 - cold hydrogenation product treatment system; 11 - washing and dust removal system; 12 - separation system; 121 - first rough separation column; 122 - second rough separation column; 123 - first rough separation column reboiler; 124 - second rough separation column reboiler; 126 - condensing device; 127 - vaporizing device; 20 - polysilicon production system; 30 - cold hydrogenation reaction system; 31 - cold hydrogenation reactor; 32 - cyclone separator; 33 - heat exchange device; 34 - trichlorosilane synthesis furnace. DETAILED DESCRIPTION
[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.
[0023] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.
[0024] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.
[0025] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "provided", "connected" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. EMBODIMENT
[0026] The present embodiment provides a cold hydrogenation product treatment system 10 and a polysilicon production system 20, please refer to Figure 1The polysilicon production system 20 comprises a cold hydrogenation reaction system 30 and the cold hydrogenation product processing system 10 of the present embodiment, and the cold hydrogenation product processing system 10 comprises a washing and dedusting system 11 and a separation system 12, the washing and dedusting system 11 is used for receiving the cold hydrogenation product and washing the cold hydrogenation product to remove impurities.
[0027] The cold hydrogenation reaction system 30 comprises a cold hydrogenation reactor 31, a cyclone separator 32 and a heat exchange device 33. The cold hydrogenation reactor 31 is used for introducing hydrogen, silicon tetrachloride mixed gas and silicon powder, and the discharge port of the cold hydrogenation reactor 31 is communicated with the inlet of the cyclone separator 32.
[0028] The gas outlet of the cyclone separator 32 is communicated with the heat exchange device 33 to introduce the gas phase separated by the cyclone separator 32 into the heat exchange device 33, the heat exchange device 33 is used for preheating hydrogen and silicon tetrachloride mixed gas, and the outlet of the heat exchange device 33 is communicated with the cold hydrogenation reactor 31 to introduce the preheated hydrogen and silicon tetrachloride mixed gas into the cold hydrogenation reactor 31.
[0029] The gas outlet of the heat exchange device 33 is communicated with the washing and dedusting system 11 to introduce the cooled gas phase into the washing and dedusting system 11 to remove impurities. The outlet of the vaporization device 127 of the cold hydrogenation product processing system 10 is communicated with the inlet of the heat exchange device 33.
[0030] The working principle of the cold hydrogenation reaction system 30 of the present application is as follows: the silicon powder and the vaporized and preheated hydrogen and silicon tetrachloride are introduced into the cold hydrogenation reactor 31 to react; the mixture after the reaction is introduced into the cyclone separator 32 to separate the solid and the gas; the gas phase separated from the cyclone separator 32 is introduced into the heat exchange device 33 to utilize the waste heat and preheat the silicon tetrachloride vaporized by the vaporization device 127. The heat exchange device 33 recovers the waste heat of the gas phase and then introduces the gas phase into the washing and dedusting system 11 to further remove impurities.
[0031] Further, the cold hydrogenation reaction system 30 further comprises a trichlorosilane synthesis furnace 34 and a synthesis gas processing device, the cyclone separator 32 has a first powder outlet and a second powder outlet, the first powder outlet is communicated with the inlet of the trichlorosilane synthesis furnace 34, so that the silicon powder separated by the cyclone separator 32 can enter the trichlorosilane synthesis furnace 34 to react with HCL; the outlet of the trichlorosilane synthesis furnace 34 is communicated with the synthesis gas processing device. The second powder outlet is communicated with the cold hydrogenation reactor 31 to supply the silicon powder into the cold hydrogenation reactor 31.
[0032] The cyclone separator 32 can divide the separated solid-phase silicon powder into two paths, one of which is introduced into the cold hydrogenation reactor 31 for reuse, and the other of which is introduced into the trichlorosilane synthesis furnace 34 to react with HCL to generate synthesis gas, which is introduced into a synthesis gas treatment device for treatment, and the treated trichlorosilane is utilized. Through the recycling of silicon powder, the production cost is further reduced, and the slurry treatment load and cost are reduced.
[0033] The separation system 12 includes a first rough separation tower 121, a second rough separation tower 122, a first rough separation tower reboiler 123, a second rough separation tower reboiler 124, a rectification device, a condensation device 126, and a vaporization device 127; the gas outlet of the washing and dust removal system 11 is in communication with the first rough separation tower reboiler 123, the first rough separation tower reboiler 123 is in communication with the condensation device 126, the gas outlet of the condensation device 126 is in communication with the first rough separation tower 121 and the second rough separation tower 122, and the first rough separation tower 121 is in communication with the rectification device. Exemplarily, the top of the first rough separation tower 121 is directly in communication with the rectification device through a production pipeline.
[0034] The second rough separation tower 122 is in communication with the second rough separation tower reboiler 124, and the second rough separation tower reboiler 124 is in communication with the rectification device; the discharge outlets of the first rough separation tower 121 and the second rough separation tower 122 are both in communication with the vaporization device 127.
[0035] The working principle of the cold hydrogenation product treatment system 10 of the present application is as follows:
[0036] The washing and dust removal system 11 introduces the gas phase after washing the cold hydrogenation product into the first rough separation tower reboiler 123 for heat exchange, and the gas phase after waste heat recovery is introduced into the condensation device 126 for condensation, and then the material is divided into two paths from the condensation device 126 and introduced into the first rough separation tower 121 and the second rough separation tower 122, respectively. Exemplarily, the washing and dust removal system 11 is in communication with the slurry device to supply the washed silicon tetrachloride into the slurry device. The washing and dust removal system 11 supplies the washed heavy component silicon tetrachloride into the slurry device, and the light component is introduced into the first rough separation tower reboiler 123 for heat exchange.
[0037] The first rough separation tower 121 and the second rough separation tower 122 can separate silicon tetrachloride, the light component separated by the first rough separation tower 121 enters a rectification device for rectification treatment, and the light component separated by the second rough separation tower 122 enters the rectification device for rectification treatment after coupling with waste heat of the second rough separation tower reboiler 124. In addition, the silicon tetrachloride separated by the first rough separation tower 121 and the second rough separation tower 122 enters a vaporization device 127 for vaporization, and can be used for preparation of cold hydrogenated products. Exemplarily, the first rough separation tower reboiler 123 and the second rough separation tower reboiler 124 are arranged in parallel and used for providing heat for the first rough separation tower 121. Exemplarily, in use, the second rough separation tower 122 is heated and separated by using 10 kg of steam, the pressure and temperature in the second rough separation tower 122 are higher than those in the first rough separation tower 121, and the heat used by the first rough separation tower 121 is obtained by coupling and using the waste heat at the top of the second rough separation tower 122 and the waste heat of the gas phase after washing and dust removal.
[0038] Optionally, the outlet of the second rough separation tower reboiler 124 is in communication with the side inlet of the second rough separation tower 122. The light component separated by the second rough separation tower 122 can enter the second rough separation tower 122 for separation after waste heat utilization by the second rough separation tower reboiler 124, so that a better separation effect can be achieved.
[0039] Further, the system further comprises a hydrogen supply pipeline and a silicon tetrachloride supply pipeline in communication with the vaporization device 127, and the hydrogen supply pipeline and the silicon tetrachloride supply pipeline are respectively used for supplying hydrogen and silicon tetrachloride to the vaporization device 127. The silicon tetrachloride separated by the first rough separation tower 121 and the second rough separation tower 122 enters the vaporization device 127, and is vaporized after hydrogen and additional silicon tetrachloride are supplied, and is preheated in the heat exchange device 33 after vaporization.
[0040] The cold hydrogenated product treatment system 10 and the polysilicon production system 20 of the present application can reduce system load, realize higher efficiency and lower failure rate by using smaller equipment and facilities through coupling design of the first rough separation tower 121 and the second rough separation tower 122 and stepwise recycling of waste heat, and can improve energy utilization rate through heat coupling utilization. In addition, production cost can be further reduced and slurry treatment load and cost can be reduced through recycling of silicon powder.
[0041] The above merely illustrates the preferred embodiments of the present application and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A cold hydrogenation product handling system characterized by, The system comprises: a washing and dust removal system for receiving and washing the cold hydrogenated product to remove impurities; the separation system comprises a first rough separation column, a second rough separation column, a first rough separation column reboiler, a second rough separation column reboiler, a rectification device, a condensation device and a vaporization device; the gas outlet of the washing and dust removal system is in communication with the first rough separation column reboiler, the first rough separation column reboiler is in communication with the condensation device, the gas outlet of the condensation device is in communication with the first rough separation column and the second rough separation column, the first rough separation column is in communication with the rectification device; the second rough separation column is in communication with the second rough separation column reboiler, the second rough separation column reboiler is in communication with the rectification device; the material outlets of the first rough separation column and the second rough separation column are both in communication with the vaporization device.
2. The cold hydrogenation product handling system of claim 1, wherein, The outlet of the second rough separation column reboiler is in communication with the side inlet of the second rough separation column.
3. The cold hydrogenation product handling system of claim 1, wherein, The first rough separation column reboiler and the second rough separation column reboiler are arranged in parallel and are used to provide heat for the first rough separation column.
4. The cold hydrogenation product handling system of claim 1, wherein, The washing and dust removal system is in communication with a slurry device for supplying the washed silicon tetrachloride into the slurry device.
5. The cold hydrogenation product handling system of any one of claims 1 to 4, wherein, It also comprises a hydrogen supply pipeline and a silicon tetrachloride supply pipeline in communication with the vaporization device, which are respectively used to supply hydrogen and silicon tetrachloride into the vaporization device.
6. The cold hydrogenation product handling system of any one of claims 1 to 4, wherein, The top of the first rough separation column is directly in communication with the rectification device through a production pipeline.
7. A polycrystalline silicon production system, characterized in that, It comprises a cold hydrogenation reaction system and the cold hydrogenated product processing system of any one of claims 1-6; the cold hydrogenation reaction system comprises a cold hydrogenation reactor, a cyclone separator and a heat exchange device, the cold hydrogenation reactor is used to pass in hydrogen, silicon tetrachloride mixed gas and silicon powder, the material outlet of the cold hydrogenation reactor is in communication with the inlet of the cyclone separator; the gas outlet of the cyclone separator is in communication with the heat exchange device to pass the gas phase separated by the cyclone separator into the heat exchange device, the heat exchange device is used to preheat hydrogen and silicon tetrachloride mixed gas, the outlet of the heat exchange device is in communication with the cold hydrogenation reactor to pass the preheated hydrogen and silicon tetrachloride mixed gas into the cold hydrogenation reactor; the gas outlet of the heat exchange device is in communication with the washing and dust removal system to pass the cooled gas phase into the washing and dust removal system to remove impurities; the outlet of the vaporization device is in communication with the inlet of the heat exchange device.
8. The polysilicon production system of claim 7, wherein It also comprises a trichlorosilane synthesis furnace, the cyclone separator has a first powder outlet, the first powder outlet is in communication with the inlet of the trichlorosilane synthesis furnace, so that the silicon powder separated by the cyclone separator can enter the trichlorosilane synthesis furnace to react with HCL.
9. The polysilicon production system of claim 8, wherein The cyclone separator also has a second powder outlet, which is in communication with the cold hydrogenation reactor to supply silicon powder into the cold hydrogenation reactor.
10. The polysilicon production system of claim 9, wherein It also comprises a synthesis gas treatment device, the outlet of the trichlorosilane synthesis furnace is in communication with the synthesis gas treatment device.