Washing tower and polycrystalline silicon preparation system

Abstract

The utility model provides a washing tower and a polycrystalline silicon preparation system, relates to the technical field of polycrystalline silicon production, and is used for solving the problem that the tail gas washing effect is poor. The washing tower comprises a shell, the shell is provided with a washing cavity, and the inner diameter size of the bottom of the washing cavity is larger than the inner diameter size of the top of the washing cavity; an air inlet and a liquid outlet which are communicated with the washing cavity are formed in the side wall, close to the bottom, of the shell, the air inlet is configured to be communicated with an air outlet of the reduction furnace, and an exhaust port is formed in the top of the shell; the spraying assembly comprises a spraying piece and a circulating pipeline, the spraying piece is provided with a spraying opening, the spraying piece is arranged at the position, close to the top, of the washing cavity, and the spraying opening faces the bottom of the washing cavity; the first end of the circulation pipeline is communicated with the liquid outlet, and the second end of the circulation pipeline is communicated with the spraying opening. The washing tower and the polycrystalline silicon preparation system provided by the utility model have the advantages of good washing effect and high impurity separation efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polysilicon production, and particularly relates to a washing tower and a polysilicon preparation system. BACKGROUND

[0002] The polysilicon reduction preparation process refers to a process of producing rod-shaped polysilicon by sending trichlorosilane and hydrogen gas mixed at a certain proportion into a reduction furnace to generate a reduction reaction.

[0003] The production process of the reduction furnace is intermittent operation, and the reduction furnace needs to be periodically opened to unload the polysilicon rod and install the silicon core. Before the reduction furnace stops deposition and is opened, nitrogen gas needs to be used to replace the gas in the reduction furnace for multiple times, and the nitrogen tail gas containing silicon powder obtained by replacement enters the washing tower, and water is used for spray washing in the washing tower. In the prior art, the washing liquid is usually extracted from the bottom of the washing tower, and a circulating pump is used to spray the washing liquid into the top of the washing tower for spray washing. However, the conventional washing tower has poor washing effect of the tail gas.

[0004] Therefore, improving the washing effect of the tail gas is a problem to be solved at present. CONTENT OF THE UTILITY MODEL

[0005] The present application provides a washing tower and a polysilicon preparation system, which have good washing effect and high impurity separation efficiency.

[0006] In a first aspect, the present application provides a washing tower suitable for a polysilicon preparation system, and the polysilicon preparation system comprises a reduction furnace and the washing tower, and the washing tower comprises:

[0007] A shell having a washing cavity, the inner diameter size of the bottom of the washing cavity is greater than the inner diameter size of the top of the washing cavity, the side wall of the shell close to the bottom has a gas inlet and a liquid outlet communicated with the washing cavity, the gas inlet is configured to be communicated with the gas outlet of the reduction furnace, and the top of the shell has a gas outlet;

[0008] A spray assembly comprising a spray piece and a circulating pipeline, the spray piece has a spray port, the spray piece is arranged at a position close to the top of the washing cavity, and the spray port is arranged to face the bottom of the washing cavity; the first end of the circulating pipeline is communicated with the liquid outlet, and the second end of the circulating pipeline is communicated with the spray port.

[0009] The washing tower as described above, the shell comprises a first connecting section and a second connecting section connected in sequence, the second connecting section is arranged above the first connecting section, the inner diameter size of the second connecting section is smaller than the inner diameter size of the first connecting section, and the gas inlet and the liquid outlet are arranged on the first connecting section;

[0010] The end of the first connecting section away from the second connecting section is further provided with a solid-gas separation part, and the inner diameter size of the solid-gas separation part gradually decreases in the direction from the top to the bottom of the washing cavity.

[0011] The scrubbing tower as claimed in any one of the preceding claims, further comprising a third connecting section, the third connecting section being arranged between the first connecting section and the second connecting section, and the third connecting section having an included angle with the horizontal plane.

[0012] The scrubbing tower as claimed in any one of the preceding claims, the included angle being 45°-60°.

[0013] The scrubbing tower as claimed in any one of the preceding claims, the first connecting section having an inner diameter size being 1.5-2 times of an inner diameter size of the second connecting section.

[0014] The scrubbing tower as claimed in any one of the preceding claims, the third connecting section having a flow guide portion on an inner wall surface thereof, the flow guide portion being configured to guide the gas entering the scrubbing cavity to the bottom of the scrubbing cavity.

[0015] The scrubbing tower as claimed in any one of the preceding claims, the flow guide portion comprising one of a flow guide protrusion and a flow guide inclined surface.

[0016] The scrubbing tower as claimed in any one of the preceding claims, further comprising a flow guide plate, the flow guide plate being detachably arranged on the inner wall surface of the third connecting section, and the flow guide portion being arranged on the flow guide plate.

[0017] The scrubbing tower as claimed in any one of the preceding claims, the shell further comprising a slag discharge port, an on-off valve and a liquid level meter; and / or,

[0018] The slag discharge port is arranged at the bottom of the first connecting section, and the slag discharge port is configured to discharge the solid particles deposited in the scrubbing cavity; and / or,

[0019] The liquid level meter is arranged in the scrubbing cavity, and the liquid level meter is configured to detect the liquid level in the scrubbing cavity, and the on-off valve is electrically connected with the liquid level meter, so that the on-off valve is opened or closed according to the detection result of the liquid level meter.

[0020] In a second aspect, the application provides a polysilicon preparation system, comprising a reduction furnace and the scrubbing tower as claimed in any one of the preceding claims, and the gas inlet of the scrubbing tower being in communication with the gas outlet of the reduction furnace.

[0021] The application provides a washing tower and a polysilicon preparation system, which are characterized in that: an air inlet and a liquid outlet are arranged at the bottom of a shell, the air inlet is communicated with an exhaust port of a reduction furnace, and nitrogen gas tail gas containing silicon powder obtained through replacement is transported into the washing tower; a spraying part is arranged in the shell, the spraying port of the spraying part and the liquid outlet of the shell are communicated with a circulating pipeline, so that the tower kettle liquid at the bottom of the washing cavity can be pumped to the top of the washing cavity and sprayed downward, thereby washing the tail gas entering the shell to realize gas-solid separation and remove the solid particles mixed in the tail gas; in addition, the shell is designed in a variable cross-section mode, that is, the inner diameter of the bottom of the shell is larger than the inner diameter of the top of the shell, so that when the tail gas enters the bottom of the washing cavity through the air inlet, the tail gas will diffuse after entering due to the larger diameter of the bottom of the washing cavity, thereby increasing the residence time of the tail gas at the bottom of the washing cavity, improving the contact efficiency of the tail gas and the spraying liquid, making the tail gas be fully pre-washed at the bottom of the shell to remove a large amount of solid particles, and then the pre-washed tail gas flows to the top of the shell and is contacted with the downward spraying liquid to be washed for the second time, thereby further removing the solid particles in the tail gas, improving the washing efficiency of the tail gas, improving the impurity separation efficiency, and having a good washing effect.

[0022] The structure of the washing tower and the polysilicon preparation system and other novel purposes and beneficial effects of the application will be more obvious and easy to understand through the description of the preferred embodiments in combination with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structure schematic view of a washing tower provided by the application;

[0024] Figure 2 is a structure schematic view of a polysilicon preparation system provided by the application.

[0025] BRIEF DESCRIPTION OF DRAWINGS

[0026] 10-polysilicon preparation system;

[0027] 100-reduction furnace; 120-exhaust port;

[0028] 200-washing tower; 210-shell; 211-washing cavity; 212-air inlet; 213-liquid outlet; 214-exhaust port; 215-first connecting section; 216-second connecting section; 217-third connecting section; 218-solid-gas separation part; 219-slag discharge port; 220-on-off valve; 221-liquid level meter;

[0029] 230-spraying assembly; 231-spraying part; 232-circulating pipeline. DETAILED DESCRIPTION

[0030] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0031] The polysilicon reduction preparation process refers to mixing trichlorosilane and hydrogen gas in a certain proportion, and then sending them into a reduction furnace to produce rod-shaped polysilicon.

[0032] The production process of the reduction furnace is intermittent operation, and the polysilicon rod needs to be unloaded and the silicon core needs to be installed periodically. Before the reduction furnace stops deposition and is opened, nitrogen gas needs to be used to replace the gas in the reduction furnace for multiple times. The nitrogen gas containing silicon powder obtained by replacement enters a washing tower, and water is used for spray washing in the washing tower. In the prior art, the washing liquid is usually extracted from the bottom of the washing tower, and a circulating pump is used to spray the washing liquid into the top of the washing tower for spray washing. However, the tail gas washing effect of the conventional washing tower is poor.

[0033] Therefore, the present application provides a washing tower and a polysilicon preparation system. The gas inlet and the liquid outlet are arranged at the bottom of the shell, and the gas inlet is communicated with the exhaust port of the reduction furnace, so as to transport the nitrogen tail gas containing silicon powder obtained by replacement into the inside of the washing tower. The spray element is arranged in the inside of the shell, and the spray nozzle of the spray element and the liquid outlet of the shell are communicated with the circulating pipeline, so that the tower kettle liquid at the bottom of the washing cavity can be sucked to the top of the washing cavity and sprayed downward, thereby washing the tail gas entering the shell. In addition, the shell is designed in a variable cross-section, so that the inner diameter of the bottom of the shell is greater than the inner diameter of the top of the shell. In this way, when the tail gas enters the bottom of the washing cavity through the gas inlet, the tail gas will diffuse after entering due to the larger diameter of the bottom of the washing cavity. At the same time, the diameter of the top of the washing cavity is smaller, and the tail gas will be subjected to a certain resistance during upward flow, thereby increasing the residence time of the tail gas at the bottom of the washing cavity, improving the contact efficiency of the tail gas and the spray liquid, and making the tail gas be fully pre-washed at the bottom of the shell to remove a large number of solid particles mixed in the tail gas. Then, the pre-washed tail gas flows to the top of the shell and is contacted with the downwardly sprayed spray liquid for secondary washing, thereby further removing the solid particles mixed in the tail gas, improving the washing efficiency of the tail gas, improving the impurity separation efficiency, and having a good washing effect.

[0034] The polysilicon preparation system in the embodiment will be further described below.

[0035] Figure 1 is a structural schematic diagram of a washing tower provided by the embodiment of the present application.

[0036] Referring to FIG. 1, a polysilicon production system 10 is provided. The polysilicon production system 10 includes a reduction furnace 100 and a washing tower 200. The washing tower 200 includes a shell 210. The shell 210 is made of a material with high strength, such as stainless steel or carbon steel. The shell 210 has a washing cavity 211. The inner diameter of the bottom of the washing cavity 211 is larger than the inner diameter of the top of the washing cavity 211. The bottom of the washing cavity 211 has a larger space and surface area, so that the tail gas stays in the washing cavity 211 for a longer time, increasing the washing time. The solid impurities in the tail gas contact with the downwardly sprayed spray liquid, so that the solid impurities are settled to the bottom of the washing tower 200 under the action of gravity, thereby removing the solid impurities in the tail gas. The larger bottom size can increase the structural stability of the washing tower 200, reduce the vibration and shaking caused by the flow of the tail gas, and improve the safety and stability of the washing tower 200. Figure 1 Referring to FIG. 1, a polysilicon production system 10 is provided. The polysilicon production system 10 includes a reduction furnace 100 and a washing tower 200. The washing tower 200 includes a shell 210. The shell 210 is made of a material with high strength, such as stainless steel or carbon steel. The shell 210 has a washing cavity 211. The inner diameter of the bottom of the washing cavity 211 is larger than the inner diameter of the top of the washing cavity 211. The bottom of the washing cavity 211 has a larger space and surface area, so that the tail gas stays in the washing cavity 211 for a longer time, increasing the washing time. The solid impurities in the tail gas contact with the downwardly sprayed spray liquid, so that the solid impurities are settled to the bottom of the washing tower 200 under the action of gravity, thereby removing the solid impurities in the tail gas. The larger bottom size can increase the structural stability of the washing tower 200, reduce the vibration and shaking caused by the flow of the tail gas, and improve the safety and stability of the washing tower 200.

[0037] Referring to FIG. 1, a polysilicon production system 10 is provided. The polysilicon production system 10 includes a reduction furnace 100 and a washing tower 200. The washing tower 200 includes a shell 210. The shell 210 is made of a material with high strength, such as stainless steel or carbon steel. The shell 210 has a washing cavity 211. The inner diameter of the bottom of the washing cavity 211 is larger than the inner diameter of the top of the washing cavity 211. The bottom of the washing cavity 211 has a larger space and surface area, so that the tail gas stays in the washing cavity 211 for a longer time, increasing the washing time. The solid impurities in the tail gas contact with the downwardly sprayed spray liquid, so that the solid impurities are settled to the bottom of the washing tower 200 under the action of gravity, thereby removing the solid impurities in the tail gas. The larger bottom size can increase the structural stability of the washing tower 200, reduce the vibration and shaking caused by the flow of the tail gas, and improve the safety and stability of the washing tower 200. Figure 1

[0038] In the present embodiment, the shell 210 has an air inlet 212 and a liquid outlet 213 on the side wall near the bottom, which are in communication with the washing cavity 211. The air inlet 212 is configured to be in communication with the gas outlet 120. The top of the shell 210 has an exhaust port 214. The washing tower 200 further includes a spraying assembly 230, which includes a spraying member 231 having a spraying port. The spraying member 231 is arranged at a position near the top of the washing cavity 211, and the spraying port faces the bottom of the washing cavity 211. Specifically, the nitrogen tail gas containing silicon powder obtained by multiple displacement of the gas in the reduction furnace 100 in the reduction furnace 100 enters the bottom of the washing cavity 211 through the air inlet 212, and then gradually diffuses in the washing cavity 211 to contact the downwardly sprayed spray liquid for washing to remove the solid impurities in the tail gas. The washed tail gas is discharged through the exhaust port 214.

[0039] Specifically, the position of the air inlet 212 is higher than the liquid level to prevent the spray liquid stored at the bottom of the washing tower 200 from flowing back to the reduction furnace 100 through the air inlet 212, affecting the normal flow of the tail gas.

[0040] It should be noted that the source of the spray liquid can have various forms, which will be described in combination with different embodiments.

[0041] ​In some possible implementation, the spraying liquid is provided by an external liquid supply source, and in particular, the external liquid supply source is in communication with the spraying port of the spraying member 231 to continuously inject the spraying liquid into the washing cavity 211 for washing the tail gas.

[0042] In some other possible implementation, the washing tower 200 is provided with a tower kettle liquid at the bottom, and the tower kettle liquid is in communication with the spraying member 231 through an external pipeline to inject the tower kettle liquid into the spraying member 231 to achieve the washing of the tail gas.

[0043] It can be understood that the source of the spraying liquid can be set according to the actual situation, and the present embodiment does not limit this.

[0044] For example, the tower kettle liquid can be water, alkaline solution and organic solvent, and the present embodiment does not limit this. In the present embodiment, the type of the tower kettle liquid is selected as water.

[0045] In the present embodiment, the spraying assembly 230 further comprises a circulating pipeline 232, the first end of the circulating pipeline 232 is in communication with the liquid outlet 213, and the second end of the circulating pipeline 232 is in communication with the spraying port, for pumping the spraying liquid injected into the bottom of the washing cavity 211 by the spraying assembly 230 to the top of the washing cavity 211 to achieve the circulating spraying.

[0046] It should be noted that since the inner diameter of the bottom of the washing cavity 211 is larger than the inner diameter of the top of the washing cavity 211, the flow resistance of the tail gas at the bottom of the washing cavity 211 is smaller, and the flow resistance at the top of the washing cavity 211 is larger, the tail gas will stay at the bottom of the washing cavity 211 for a long time to fully contact with the spraying liquid injected downward by the spraying member 231 for pre-washing to remove a large amount of silicon powder inside the tail gas, and then the pre-washed tail gas flows upward to contact with the spraying liquid for secondary washing to further remove the solid impurities in the tail gas, and the washed tail gas is discharged through the exhaust port.

[0047] In particular, the silicon powder removed from the inside of the tail gas will be deposited at the bottom of the shell 210, in order to prevent the silicon powder deposited at the bottom of the shell 210 from being pumped into the spraying member 231 by the circulating pipeline 232 to block the spraying port and reduce the spraying amount of the spraying member 231 and the impurity removal effect of the tail gas, the position of the liquid outlet 213 should be reasonably set to ensure that the circulating pipeline 232 only pumps the upper clear liquid at the bottom of the shell 210 each time.

[0048] In an implementable embodiment, the shell 210 comprises a first connecting section 215 and a second connecting section 216 connected in sequence, the second connecting section 216 is arranged above the first connecting section 215, the inner diameter size of the second connecting section 216 is smaller than that of the first connecting section 215, and the gas inlet 212 and the liquid outlet 213 are both arranged on the first connecting section 215.

[0049] The end of the first connecting section 215 away from the second connecting section 216 is further provided with a solid-gas separation part 218, and the inner diameter size of the solid-gas separation part 218 gradually decreases in the direction from the top to the bottom of the washing cavity 211.

[0050] In the present embodiment, continuing to refer to Figure 1 As shown in the figure, the solid-gas separation part 218 is in the shape of a circular arc. The purpose of designing the solid-gas separation part 218 in the shape of a circular arc is to make the silicon powder removed by the liquid washing flow more smoothly into the recess at the bottom of the shell 210, so as to facilitate collection and subsequent processing, and to increase the distance between the liquid outlet 213 and the bottom of the shell 210, so as to prevent the silicon powder and the spray liquid stored at the bottom of the shell 210 from being mixed together and being injected into the shell 210 through the circulation pipeline 232 via the liquid outlet 213, so as to block the spray nozzles 231.

[0051] In an implementable embodiment, a third connecting section 217 is further included, the third connecting section 217 is arranged between the first connecting section 215 and the second connecting section 216, and the third connecting section 217 has an included angle with the horizontal plane.

[0052] In the present embodiment, referring to Figure 1 and Figure 2 As shown in the figure, the third connecting section 217 is arranged between the first connecting section 215 and the second connecting section 216, and plays a transitional role. The tail gas entering the inside of the shell 210 first flows into the first connecting section 215, so that the tail gas is first fully contacted with the spray liquid for pre-washing, and then is transferred into the second connecting section 216 via the third connecting section 217.

[0053] Specifically, the third connecting section 217 has an included angle with the horizontal plane. The purpose of this arrangement is to promote the spiral rising or vortex formation of the tail gas in the washing tower 200, increase the contact time and contact area between the tail gas and the spray liquid, thereby improving the washing effect, and this inclined surface design also helps to reduce the accumulation of impurities on the inner side wall of the washing tower 200.

[0054] For example, the included angle can be selected as 45°, 60° or any value between 45° and 60°. In the present embodiment, the included angle of the third connecting section 217 is not limited, as long as it can ensure the stable operation of the washing tower 200 under various working conditions.

[0055] In an implementable embodiment, the inner diameter of the first connecting section 215 is 1.5-2 times of the inner diameter of the second connecting section 216.

[0056] Specifically, in the embodiment, the inner diameter of the first connecting section 215 can be selected as 800mm, 1000mm or any value between 800mm and 1000mm, and the inner diameter of the second connecting section 216 can be selected as 300mm, 500mm or any value between 300mm and 500mm.

[0057] In an implementable embodiment, the inner wall surface of the third connecting section 217 is provided with a flow guide part configured to change the flow direction of the tail gas entering the inside of the shell 210, so as to guide the tail gas entering the scrubbing cavity 211 to the bottom of the scrubbing cavity 211, so as to increase the contact time of the tail gas and the spraying liquid, so that the tail gas and the spraying liquid are more fully contacted.

[0058] As an optional embodiment, the flow guide part is a flow guide protrusion, and a plurality of flow guide protrusions are arranged on the inner wall surface of the third connecting section 217, which is arranged to improve the distribution of the tail gas and make the tail gas uniformly distributed in the shell 210.

[0059] As another optional embodiment, the flow guide part is a flow guide slope, which is fixedly arranged on the inner side wall of the third connecting section 217, and has an included angle with the third connecting section 217, which is used to guide the flow direction of the tail gas, change the path of the tail gas, prevent the tail gas from flowing upward in the shell 210, and make the tail gas stay at the bottom of the shell 210, so as to increase the contact time of the tail gas and the spraying liquid, thereby removing a large amount of silicon powder carried in the tail gas.

[0060] Specifically, referring to Figures 1 to 2 As shown in the figure, the arrow represents the flow direction of the tail gas. When the tail gas enters the shell 210 from the gas inlet 212, the tail gas first flows to the bottom of the shell 210. Since the inner diameter of the top of the shell 210 is smaller than the inner diameter of the bottom of the shell 210, when the tail gas flows upward, the flow resistance will increase. When the tail gas moves to the third connecting section 217, the tail gas changes the flow direction and flows downward.

[0061] In an implementable embodiment, a guide plate is further included, which is detachably arranged on the inner wall surface of the third connecting section 217, and the purpose of such arrangement is to facilitate disassembly and subsequent cleaning. Specifically, a guide portion is further fixedly arranged on the guide plate. For example, the guide portion is the aforementioned guide slope or guide protrusion. When the guide portion is the guide protrusion, the guide portion is threadedly connected, clamped or integrally formed on the guide plate. When the guide portion is the guide slope, the guide portion is integrally formed with the guide plate. In this embodiment, the connection mode of the guide portion and the guide plate is not limited, as long as the guide portion is fixedly arranged on the guide plate.

[0062] As another optional embodiment, the guide plate is integrally formed with the third connecting section 217, which can enhance the connection strength of the third connecting section 217 and the guide plate, and the guide plate also has a certain buffering effect, which can buffer the impact force generated when the exhaust gas flow and the scrubbing tower 200 interact, protect the shell 210 from being damaged by direct impact, and prolong the service life of the scrubbing tower 200.

[0063] In this embodiment, the shell 210 further includes a slag discharge port 219 arranged at the bottom of the first connecting section 215, which is used to discharge the solid particles deposited in the scrubbing cavity 211. Specifically, the solid particles include silicon powder and impurities or dust particles from the raw materials.

[0064] In this embodiment, a liquid level meter 221 and a switch valve 220 are further arranged in the scrubbing cavity 211. The liquid level meter 221 is configured to detect the liquid level in the scrubbing cavity 211, and the switch valve 220 is electrically connected with the liquid level meter 221, so that the switch valve 220 is opened or closed according to the detection result of the liquid level meter 221.

[0065] Specifically, when the liquid level meter 221 detects that the liquid level inside the shell 210 is lower than a certain value, it indicates that the liquid in the scrubbing tower 200 is not sufficient to effectively absorb the impurities in the reduced exhaust gas. At this time, the switch valve 220 is controlled to be opened to discharge the impurities.

[0066] The embodiment of the present application provides a washing tower 200, which is suitable for a polysilicon preparation system 10, the polysilicon preparation system 10 comprises a reduction furnace 100 and the washing tower 200, and the washing tower 200 comprises: a shell 210, the shell 210 has a washing cavity 211, the inner diameter size of the bottom of the washing cavity 211 is greater than the inner diameter size of the top of the washing cavity 211, the shell 210 is provided with an air inlet 212 and a liquid outlet 213 which are communicated with the washing cavity 211 on the side wall close to the bottom, the air inlet 212 is configured to be communicated with the gas outlet 120 of the reduction furnace 100, and the top of the shell 210 is provided with an exhaust port 214; a spraying assembly 230 comprising a spraying piece 231 and a circulating pipeline 232, the spraying piece 231 is provided at a position close to the top of the washing cavity 211 and is provided with a spraying port facing the bottom of the washing cavity 211; the first end of the circulating pipeline 232 is communicated with the liquid outlet 213, and the second end of the circulating pipeline 232 is communicated with the spraying port. In this way, the air inlet 212 and the liquid outlet 213 are arranged at the bottom of the shell 210, the air inlet 212 is communicated with the exhaust port 214 of the reduction furnace, so that the nitrogen tail gas containing silicon powder obtained by replacement is transported to the inside of the washing tower; the spraying piece 231 is arranged in the shell 210, and the spraying port of the spraying piece 231 and the liquid outlet 213 of the shell 210 are communicated with the circulating pipeline 232, so that the tower kettle liquid at the bottom of the washing cavity 211 can be pumped to the top of the washing cavity 211 and sprayed downward, thereby washing the tail gas entering the inside of the shell 210; in addition, the shell 210 adopts a variable cross-section design, so that the inner diameter of the bottom of the shell 210 is greater than the inner diameter of the top of the shell 210; in this way, when the tail gas enters the bottom of the washing cavity 211 through the air inlet 212, the tail gas will diffuse after entering due to the larger diameter of the bottom of the washing cavity 211, and the tail gas will be subjected to a certain resistance during upward flow due to the smaller diameter of the top of the washing cavity 211, thereby increasing the residence time of the tail gas at the bottom of the washing cavity 211, improving the contact efficiency of the tail gas and the spraying liquid, so that the tail gas is fully prewashed at the bottom of the shell 210, then the prewashed tail gas flows to the top of the shell 210 for secondary washing, the washing efficiency of the tail gas can be improved, the impurity separation efficiency is improved, and a good washing effect is achieved.

[0067] Reference Figure 2 As shown in the drawings, the embodiment also provides a polysilicon preparation system, which comprises the reduction furnace 100 and the washing tower 200.

[0068] Wherein, the specific structure, functions and working principles of the washing tower 200 have been described in detail in the foregoing embodiment, and will not be repeated here.

[0069] Specifically, the reducing furnace 100 is also provided with a temperature control device (not shown in the figure) for accurately controlling the temperature during the reduction process to ensure that the reduction reaction occurs in the optimal temperature range, avoiding the situation that the reaction is blocked or the product is impure due to too high or too low temperature.

[0070] In order to ensure the corrosion resistance of the reducing furnace 100 in a high-temperature and high-oxide environment, the reducing furnace 100 is made of high-temperature alloy steel or stainless steel, etc. The material of the reducing furnace 100 is not limited in the embodiment, as long as it can meet the requirement that the reducing furnace 100 can serve in a high-temperature environment for a long time.

[0071] In the embodiment, continuing to refer to Figure 2 As shown in the figure, the number of the gas outlet 120 can be one, and the one gas outlet 120 is arranged at the top of the reducing furnace 100 to ensure that the reduction tail gas flows uniformly from bottom to top. Specifically, the number of the gas outlet 120 can be multiple, and the multiple gas outlets 120 are arranged along the circumference of the reducing furnace 100 to ensure that the reduction tail gas is uniformly discharged, avoiding the situation of local overheating or poor air flow. The number of the gas outlet 120 is not limited in the embodiment, as long as it can ensure that the reduction tail gas is smoothly discharged.

[0072] The terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0073] In the embodiments of the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "back", etc. indicate the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to indicating the orientation or positional relationship, the above-mentioned terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain attachment relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the embodiments of the present application can be understood according to the specific circumstances.

[0074] In addition, the terms "set", "connected", and "fixed" should be construed broadly. For example, "connected" can be fixed connection, detachable connection, or integral configuration; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium, or internal connection between two devices, elements or components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present disclosure according to the specific circumstances.

[0075] It should be noted that the embodiments referred to in the specification as "one embodiment", "an embodiment", "example embodiment", "some embodiments", etc., can include specific features, structures or characteristics, but not necessarily every embodiment. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure or characteristic is described in connection with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure or characteristic in connection with other embodiments, whether explicitly described or not.

[0076] Generally, the terms should be understood at least partly by the context of use. For example, at least partly according to the context, the term "one or more" used in the text can be used to describe any feature, structure or characteristic of singular meaning, or can be used to describe a combination of features, structures or characteristics of plural meaning. Similarly, at least partly according to the context, terms such as "a" can be understood to convey singular usage or to convey plural usage.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A scrubbing tower suitable for use in a polysilicon production system (10) comprising a reduction furnace (100) and a scrubbing tower (200), characterized in that, The washing tower (200) comprises: a shell (210) having a washing cavity (211), an inner diameter size of a bottom of the washing cavity (211) being larger than an inner diameter size of a top of the washing cavity (211), the shell (210) having an air inlet (212) and a liquid outlet (213) on a side wall close to the bottom and communicating with the washing cavity (211), the air inlet (212) being configured to communicate with an air outlet (120) of the reduction furnace (100), the top of the shell (210) having an exhaust port (214); a spraying assembly (230) comprising a spraying member (231) having a spraying port and a circulating pipeline (232), the spraying member (231) being arranged at a position close to the top of the washing cavity (211) and the spraying port being arranged to face the bottom of the washing cavity (211), a first end of the circulating pipeline (232) communicating with the liquid outlet (213) and a second end of the circulating pipeline (232) communicating with the spraying port.

2. The scrubbing column of claim 1, wherein, The shell (210) comprises a first connecting section (215) and a second connecting section (216) connected in sequence, the second connecting section (216) being arranged above the first connecting section (215), an inner diameter size of the second connecting section (216) being smaller than an inner diameter size of the first connecting section (215), the air inlet (212) and the liquid outlet (213) being arranged on the first connecting section (215). An end of the first connecting section (215) away from the second connecting section (216) is further provided with a solid-gas separation part (218), an inner diameter size of the solid-gas separation part (218) gradually decreasing in a direction from the top to the bottom of the washing cavity (211).

3. The scrubbing column of claim 2, wherein, A third connecting section (217) is further included, the third connecting section (217) being arranged between the first connecting section (215) and the second connecting section (216) and having an included angle with a horizontal plane.

4. The scrubbing column of claim 3, wherein, The included angle is 45°-60°.

5. The scrubbing column according to any one of claims 2-4, characterized in that, The inner diameter size of the first connecting section (215) is 1.5-2 times the inner diameter size of the second connecting section (216).

6. The scrubbing column of claim 3 wherein, The inner wall surface of the third connecting section (217) has a flow guide part configured to guide the gas entering the washing cavity (211) to the bottom of the washing cavity (211).

7. The scrubbing column of claim 6, wherein, The flow guide part comprises one of a flow guide protrusion and a flow guide inclined surface.

8. The scrubbing column of claim 6 wherein, A flow guide plate is further included, the flow guide plate being detachably arranged on the inner wall surface of the third connecting section (217), the flow guide part being arranged on the flow guide plate.

9. The scrubbing column according to any one of claims 2-4, characterized in that, The shell (210) further comprises a slag discharge port (219), an on-off valve (220) and a liquid level meter (221); and / or, The slag discharge port (219) is arranged at the bottom of the first connecting section (215) and is configured to discharge the solid particles deposited in the washing cavity (211); and / or, The liquid level meter (221) is arranged in the washing cavity (211), and is configured to detect the liquid level in the washing cavity (211); and the switch valve (220) is electrically connected with the liquid level meter (221), so that the switch valve (220) opens or closes the residue discharge port (219) according to the detection result of the liquid level meter (221).

10. A polysilicon production system comprising: The reduction furnace (100) and the washing tower (200) according to any one of claims 1-9, wherein the gas inlet (212) of the washing tower (200) is communicated with the gas outlet (120) of the reduction furnace (100).

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