A polysilicon acid washing waste gas treatment system

Abstract

The utility model relates to the technical field of polysilicon production, and in particular to a polysilicon pickling waste gas treatment system, comprising: a spray tower, with a feeding port at the top, a composite block inside, and a tower kettle at the bottom; the composite block is composed of a distillation filler and a photocatalytic oxidation catalyst; a venturi mixer, one end of which is connected to the tower kettle, and an air inlet is provided on the top; an ozone generation module is connected to the other end of the venturi mixer, including an ozone generator and an ozone decomposer; a gas-liquid separation module, with a connection port at the top and a connection port at the side, the top connection port is connected to the ozone generation module, and the side connection port is connected to the spray tower. In the utility model, by utilizing the low-pressure area formed by ozone in the venturi mixer, the pickling waste gas is sucked in and treated, the composite block accelerates the reaction of the pickling waste gas with lime water, and improves the treatment efficiency. The system integrates the spray tower, the ozone generation module, the venturi mixer and the gas-liquid separation module, and optimizes the treatment process.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon production, in particular to a polysilicon acid washing waste gas treatment system. Background Art

[0002] In the polysilicon post-processing process, pickling of silicon materials is a key step, which mainly uses nitric acid and hydrofluoric acid to etch impurities on the surface of silicon materials, thereby improving the quality of the product. In this process, the reaction of silicon materials with nitric acid may produce nitrogen oxides, and the heating of hydrofluoric acid will release a large amount of hydrofluoric acid gas. In order to deal with these harmful gases, alkali spray tower technology is usually used, in which the low-cost quicklime water is used as the alkali. Quicklime water can effectively absorb hydrofluoric acid gas, but the resulting calcium fluoride precipitate is difficult to dissolve in water, which may cause the packing of the spray tower to gradually clog, requiring regular cleaning, increasing maintenance costs and labor intensity. At the same time, the reaction efficiency of conventional nitrogen oxides with quicklime water under such conditions is low, and it is difficult to achieve complete harmless treatment through this method.

[0003] In order to solve the above problems, a polysilicon acid washing waste gas treatment system is designed.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Utility Model Content

[0005] The utility model provides a polysilicon acid washing waste gas treatment system, thereby effectively solving the problems in the background technology.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a polysilicon pickling waste gas treatment system, comprising:

[0007] A spray tower, wherein a feeding port is arranged at the top of the spray tower, a plurality of composite blocks are arranged inside, and a tower kettle is fixedly arranged at the bottom;

[0008] The feeding port is used to inject lime water into the spray tower; the composite blocks are composed of distillation fillers and photocatalytic oxidation catalysts, and are used to promote the reaction between pickling waste gas and lime water; the tower kettle is used to collect and store the reaction liquid in the spray tower;

[0009] A venturi mixer, one end of which is connected to the tower kettle and an air inlet is provided on the top, and the air inlet is used to inhale the pickling waste gas;

[0010] An ozone generating module, which is connected to the other end of the Venturi mixer and includes an ozone generator and an ozone decomposer;

[0011] A gas-liquid separation module is provided with a connection port on the top and a connection port on the side. The top connection port is communicated with the ozone generating module, and the side connection port is communicated with the spray tower.

[0012] Furthermore, a plurality of groups of ultraviolet light components are arranged in the composite block, and the ultraviolet light components are used to promote the reaction between nitrogen oxides and ozone in the pickling waste gas.

[0013] Furthermore, a plurality of partitions with notches are arranged in the tower kettle, and the uppermost partition is located below the liquid level of the reaction liquid.

[0014] Furthermore, the partitions are staggered in the vertical direction.

[0015] Furthermore, a buffer tank is provided between the ozone generating module and the venturi mixer, and a monitor is provided on the buffer tank, and the monitor is used to monitor the ozone concentration in the buffer tank;

[0016] Wherein, when the ozone concentration in the buffer tank is lower than a preset value, the gas in the buffer tank is discharged into the ozone decomposer and discharged after being decomposed.

[0017] Furthermore, the ozone that has not completely reacted in the spray tower passes through the gas-liquid separation module and is re-transported to the ozone generation module for continued recycling.

[0018] Furthermore, a compressor is provided between the buffer tank and the venturi mixer.

[0019] Furthermore, the inner walls of the spray tower, the tower kettle and the venturi mixer are all made of corrosion-resistant materials.

[0020] The beneficial effects of the utility model are as follows: by utilizing the low-pressure zone formed by ozone in the venturi mixer, the pickling waste gas is sucked in and treated, HF in the tail gas and other acid gases are treated step by step, HF is retained in the tower bottom in advance, and thus the generated calcium fluoride precipitation is prevented from clogging the composite module; the composite module accelerates the reaction of other pickling waste gases with lime water, and improves the efficiency of pickling waste gas treatment. The system as a whole integrates the spray tower, the ozone generation module, the venturi mixer and the gas-liquid separation module, optimizes the pickling waste gas treatment process, and reduces the total amount of pickling waste gas to be treated. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of a polysilicon acid washing waste gas treatment system;

[0023] Figure 2 It is a schematic diagram of the tower kettle structure;

[0024] Figure 3 It is a schematic diagram of the composite block structure;

[0025] Figure numerals: 1. spray tower; 11. feed port; 12. composite module; 12A. ultraviolet light component; 13. tower bottom; 13A. partition; 2. venturi mixer; 21. air inlet; 3. ozone generation module; 31. ozone generator; 32. ozone decomposer; 4. gas-liquid separation module; 41. connection port; 5. buffer tank; 51. monitor; 6. compressor. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0027] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by “center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “inside” and “outside”, etc., are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figures 1 to 3As shown, a polysilicon pickling waste gas treatment system comprises:

[0030] A spray tower 1, wherein a feeding port 11 is arranged at the top of the spray tower 1, a plurality of composite blocks 12 are arranged inside, and a tower kettle 13 is fixedly arranged at the bottom;

[0031] The feed port 11 is used to inject lime water into the spray tower 1; the plurality of composite blocks 12 are composed of a distillation filler and a photocatalytic oxidation catalyst, and are used to promote the reaction between the pickling waste gas and the lime water; the tower kettle 13 is used to collect and store the reaction liquid in the spray tower 1;

[0032] A venturi mixer 2, one end of which is connected to the tower kettle 13, and an air inlet 21 is provided on the top, and the air inlet 21 is used to inhale the pickling waste gas;

[0033] An ozone generating module 3, which is connected to the other end of the venturi mixer 2, and includes an ozone generator 31 and an ozone decomposer 32;

[0034] The gas-liquid separation module 4 has a connection port 41 at the top and a connection port 41 at the side. The top connection port 41 is connected to the ozone generating module 3 , and the side connection port 41 is connected to the spray tower 1 .

[0035] Lime water is injected into the tower through the feeding port 11 at the top of the spray tower 1. At the same time, the ozone generated by the ozone generating module 3 enters through one end of the venturi mixer 2, forming a low-pressure area in the venturi mixer 2, and the pickling waste gas is sucked in from the air inlet 21 of the venturi mixer 2. The pickling waste gas and the ozone generated by the ozone generator 31 are mixed in the venturi mixer 2 and then enter the tower kettle 13 of the spray tower 1. The composite module 12 inside the spray tower 1 promotes the reaction between the pickling waste gas and the lime water. The treated pickling waste gas is discharged from the tower kettle 13, and the incompletely reacted ozone passes through the gas-liquid separation module 4 and is recirculated to the ozone generating module 3 for continued use.

[0036] The system utilizes the low-pressure zone formed by ozone in the Venturi mixer 2 to inhale and treat the pickling waste gas. The composite module 12 accelerates the reaction between the pickling waste gas and lime water, thereby improving the efficiency of the pickling waste gas treatment. The system as a whole integrates the spray tower 1, the ozone generation module 3, the Venturi mixer 2 and the gas-liquid separation module 4, thereby optimizing the pickling waste gas treatment process and reducing the total amount of pickling waste gas to be treated.

[0037] As a preferred embodiment of the above embodiment, a plurality of groups of ultraviolet light components 12A are arranged in the composite block 12, and the ultraviolet light components 12A are used to promote the reaction between nitrogen oxides in the pickling waste gas and ozone.

[0038] Through the photocatalytic effect of multiple groups of ultraviolet light components 12A, the reaction rate of nitrogen oxides and ozone in the pickling waste gas is accelerated, which not only converts harmful substances into harmless substances more quickly, but also enhances the effect of the entire pickling waste gas treatment process. In addition, the effect of ultraviolet light ensures the thoroughness of the reaction, reduces the emission of residual harmful substances, and improves the overall processing capacity of the system.

[0039] As a preferred embodiment of the above embodiment, a plurality of partitions 13A with notches are provided in the bottom of the tower 13, and the uppermost partition 13A is located below the liquid level of the reaction liquid.

[0040] The pickling waste gas will first enter the tower kettle 13 through the venturi mixer 2. A number of partitions 13A with notches are arranged inside the tower kettle 13, and the uppermost partition 13A is located below the liquid level of the reaction liquid. After the hydrogen fluoride (HF) in the pickling waste gas enters the tower kettle 13, it contacts with the reaction liquid and fully flows and reacts horizontally under the action of the partition 13A. The products generated after the reaction are collected at the bottom of the tower kettle 13, while other untreated pickling waste gas continues to move upward and enters the spray tower 1 for further treatment.

[0041] By providing a notched partition 13A in the tower kettle 13, the hydrogen fluoride in the pickling waste gas can be effectively intercepted and fully reacted, thereby avoiding its precipitation and clogging problems in the filler. In addition, by utilizing segmented treatment, a preliminary reaction can be specifically performed on the hydrogen fluoride, making the subsequent treatment of other pickling waste gases in the spray tower 1 more efficient and smooth, thereby ensuring the stable operation and long-term treatment capacity of the overall pickling waste gas treatment system.

[0042] In this embodiment, the partitions 13A are staggered in the vertical direction.

[0043] The partitions 13A are staggered in the vertical direction, which effectively increases the contact area and contact time between the pickling waste gas and the reaction liquid, thereby enhancing the thoroughness of the reaction. The staggered design allows the pickling waste gas to change its flow direction multiple times in the tower bottom 13, ensuring that the pickling waste gas can be fully mixed with the reaction liquid, effectively preventing the pickling waste gas from which hydrogen fluoride has not been completely removed from entering the subsequent treatment stage, reducing precipitation and blockage problems, and improving the treatment efficiency and operating stability of the overall pickling waste gas treatment system.

[0044] In this embodiment, a buffer tank 5 is provided between the ozone generating module 3 and the venturi mixer 2, and a monitor 51 is provided on the buffer tank 5, and the monitor 51 is used to monitor the ozone concentration in the buffer tank 5;

[0045] When the ozone concentration in the buffer tank 5 is lower than a preset value, the gas in the buffer tank 5 is discharged to the ozone decomposer 32 and discharged after being decomposed.

[0046] The ozone generated by the ozone generating module 3 enters the buffer tank 5. A monitor 51 is provided on the buffer tank 5 to monitor the ozone concentration in the tank in real time. When the ozone concentration in the buffer tank 5 reaches a preset value, the ozone will be mixed with the pickling waste gas through the venturi mixer 2 and enter the spray tower 1 for further treatment. If the ozone concentration in the buffer tank 5 is lower than the preset value, the monitor 51 will trigger the system to guide the gas in the buffer tank 5 to the ozone decomposer 32 for decomposition treatment, and the decomposed gas will be discharged to the external environment.

[0047] By setting a buffer tank 5 between the ozone generating module 3 and the venturi mixer 2 and equipping it with a monitor 51, the stability of the ozone concentration in the system and the appropriate supply can be ensured to avoid the problem of excessive or insufficient ozone. The ozone concentration in the buffer tank 5 can be monitored and adjusted in real time to ensure the effective use of ozone and avoid the potential harm to the environment caused by ozone leakage. When the ozone concentration is insufficient, the gas is guided to the ozone decomposer 32 for safe decomposition, further ensuring the safety and environmental protection of the system.

[0048] In this embodiment, the ozone that has not been completely reacted in the spray tower 1 passes through the gas-liquid separation module 4 and is re-transported to the ozone generation module 3 for continued recycling.

[0049] By separating the incompletely reacted ozone in the spray tower 1 through the gas-liquid separation module 4 and then re-transporting it to the ozone generation module 3 for recycling, the utilization rate of ozone is significantly improved, the incompletely reacted ozone is recycled, the waste of ozone is reduced, the operating costs are reduced, and the efficiency and economy of the pickling waste gas treatment system are further improved. By recycling ozone, the emission burden on the environment is reduced and the environmental protection performance of the system is improved.

[0050] In this embodiment, a compressor 6 is provided between the buffer tank 5 and the venturi mixer 2 .

[0051] By arranging a compressor 6 between the buffer tank 5 and the venturi mixer 2, the transport efficiency of ozone can be effectively improved. The compressor 6 ensures that the ozone maintains an appropriate pressure during the transport process, thereby optimizing the mixing effect of ozone and pickling waste gas in the venturi mixer 2, improving the uniformity and reaction rate of gas mixing, and helping to enhance the overall efficiency of the pickling waste gas treatment system. The application of the compressor 6 can also stabilize the operation of the system, avoid treatment instability caused by pressure fluctuations, and thus improve the reliability and sustainability of the system.

[0052] In this embodiment, the inner walls of the spray tower 1, the tower kettle 13 and the venturi mixer 2 are all made of corrosion-resistant materials.

[0053] The inner walls of the spray tower 1, the tower kettle 13 and the venturi mixer 2 are made of corrosion-resistant materials, which significantly prolongs the service life of key components and reduces equipment damage and maintenance frequency caused by corrosion. The corrosion-resistant materials can effectively resist the erosion of corrosive media such as pickling waste gas and lime water, and maintain the structural integrity and functional stability of the system. This design not only reduces the maintenance and replacement costs of the system, but also improves the reliability and operation efficiency of the entire pickling waste gas treatment system, ensuring long-term stable and efficient treatment of pickling waste gas.

[0054] Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the description are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A polysilicon pickling waste gas treatment system, characterized in that: include: A spray tower, wherein a feeding port is arranged at the top of the spray tower, a plurality of composite blocks are arranged inside, and a tower kettle is fixedly arranged at the bottom; The feeding port is used to inject lime water into the spray tower; the composite blocks are composed of distillation fillers and photocatalytic oxidation catalysts, and are used to promote the reaction between pickling waste gas and lime water; the tower kettle is used to collect and store the reaction liquid in the spray tower; a plurality of partitions with notches are arranged in the tower kettle, and the uppermost partition is located below the liquid level of the reaction liquid; the partitions are staggered in the vertical direction; A venturi mixer, one end of which is connected to the tower kettle and an air inlet is provided on the top, and the air inlet is used to inhale the pickling waste gas; An ozone generating module, which is connected to the other end of the Venturi mixer and includes an ozone generator and an ozone decomposer; A gas-liquid separation module is provided with a connection port on the top and a connection port on the side. The top connection port is communicated with the ozone generating module, and the side connection port is communicated with the spray tower.

2. The polysilicon pickling waste gas treatment system according to claim 1, characterized in that: A plurality of groups of ultraviolet light components are arranged in the composite block, and the ultraviolet light components are used to promote the nitrogen oxides in the pickling waste gas to react with ozone.

3. The polysilicon pickling waste gas treatment system according to claim 1, characterized in that: A buffer tank is provided between the ozone generating module and the venturi mixer, and a monitor is provided on the buffer tank, and the monitor is used to monitor the ozone concentration in the buffer tank; Wherein, when the ozone concentration in the buffer tank is lower than a preset value, the gas in the buffer tank is discharged into the ozone decomposer and discharged after being decomposed.

4. The polysilicon pickling waste gas treatment system according to claim 1, characterized in that: The ozone that has not been completely reacted in the spray tower passes through the gas-liquid separation module and is re-transported to the ozone generation module for continued recycling.

5. The polysilicon pickling waste gas treatment system according to claim 3, characterized in that: A compressor is arranged between the buffer tank and the venturi mixer.

6. The polysilicon pickling waste gas treatment system according to claim 1, characterized in that: The inner walls of the spray tower, the tower kettle and the Venturi mixer are all made of corrosion-resistant materials.

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