A treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas

Abstract

The application discloses a treatment process for directly recycling hydrofluoric acid from fluorine-containing waste gas and belongs to the field of waste gas treatment. The process comprises the following steps: a. fluorine-containing waste gas enters a temperature and humidity regulator, waste gas is cooled through adiabatic evaporation, and fluorine in the waste gas is dissolved in water to form HF; b. the waste gas enters a condenser, the waste gas is cooled, and HF is condensed into hydrofluoric acid; c. the waste gas enters a washing tower for flushing, and the hydrofluoric acid enters a storage tank for storage; d. the waste gas is sent to the next process for treatment after being flushed by the washing tower; and e. flushing liquid in the washing tower is pumped into the temperature and humidity regulator by a circulating pump to form water mist. The fluorine-containing waste gas can be treated in a more energy-saving and environment-friendly manner.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and in particular to a treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas. Background Technology

[0002] In the production processes of chemicals, metallurgy, and feed additives, some factories generate fluorine-containing waste gases (such as waste gas from smelting furnaces during yellow phosphorus production, waste gas from roasting lead-zinc smelting slag, waste gas from roasting rare earth smelting, and waste gas from the roasting process of TCP feed calcium phosphate additive production). Fluorine mainly exists in the form of HF, and it is mostly accompanied by sulfur dioxide. If the fluorine in the waste gas cannot be effectively treated, it will have a significant impact on subsequent treatment processes and equipment.

[0003] Currently, the treatment methods for this type of fluorine-containing waste gas can be broadly classified into the following two categories: The first category is alkaline absorption, which uses alkali as an absorbent for treatment. This method typically uses sodium hydroxide or lime as the absorbent to absorb gases such as hydrogen fluoride and sulfur dioxide from the waste gas. This method has a short process and low investment. However, it wastes some fluorine resources and generates a large amount of wastewater or fluorine-containing calcium slag, causing relatively serious secondary pollution.

[0004] The second type involves water washing absorption, which uses water washing to absorb hydrogen fluoride from the waste gas into an aqueous solution, producing a hydrofluoric acid solution. The waste gas after absorbing the hydrogen fluoride is then sent to subsequent desulfurization or other treatment processes. However, because this method introduces a large amount of water, the resulting hydrofluoric acid solution has a very low concentration and can only be discharged to a wastewater treatment plant for processing. Alternatively, the low-concentration hydrofluoric acid can be concentrated before it can be sold as a product. Although this method utilizes the fluorine resources in the waste gas and reduces secondary pollution, the concentration requires a significant amount of steam and electricity, making it an inefficient method.

[0005] Therefore, finding a more energy-efficient and environmentally friendly method for treating fluorinated waste gas is essential for the clean production operation of similar factories. Summary of the Invention

[0006] To achieve more energy-efficient and environmentally friendly treatment of fluorine-containing waste gas, this application provides a treatment process for the direct recovery of hydrofluoric acid from fluorine-containing waste gas, employing the following technical solution: A process for directly recovering hydrofluoric acid from fluorine-containing waste gas includes the following steps: a. Fluorine-containing waste gas enters the temperature and humidity regulator, where it is cooled down through adiabatic evaporation. At the same time, the fluorine in the waste gas dissolves in water and combines to form HF. b. The exhaust gas enters the condenser to cool it down, and at the same time, it can condense HF into hydrofluoric acid. c. The exhaust gas enters the scrubbing tower for rinsing, and the hydrofluoric acid enters the storage tank for storage; d. After being washed by the scrubbing tower, the waste gas is sent to the next process for treatment; e. The flushing liquid in the scrubbing tower is pumped into the temperature and humidity regulator by a circulating pump to form water mist.

[0007] By adopting the above technical solution and following the steps, the exhaust gas can be cooled through adiabatic evaporation. Compared with conventional cooling methods, this cooling method, which combines water mist and exhaust gas, is more rapid and does not waste a large amount of water resources. Simultaneously, fluorine dissolves in the water mist, and because it is a water mist, the water volume is very small. Therefore, in subsequent steps, the water mist containing dissolved HF can be condensed into highly concentrated hydrofluoric acid, which can be used directly as a concentrated product without further concentration steps, making it more energy-efficient and environmentally friendly. The exhaust gas is washed through a scrubbing tower, minimizing the fluorine content in the exhaust gas. The amount of rinsing liquid is sufficient for subsequent waste gas treatment. Since the rinsing liquid contains fluorine, it typically requires treatment. In this application, the rinsing liquid is directly fed into a temperature and humidity regulator to become water mist, providing preliminary treatment of the waste gas. This ensures the water mist contains fluorine from the outset. The fluorine dissolves in the water mist, resulting in a higher fluorine content of 95%. Upon condensation, the water mist directly forms a highly concentrated hydrofluoric acid product. Therefore, this application eliminates the need for treatment of the water mist and rinsing water, making it more convenient and eliminating wastewater generation, thus being more energy-efficient and environmentally friendly.

[0008] Optionally, in step a, a suitable temperature and humidity are selected based on the required concentration of hydrofluoric acid in the product and the composition of the exhaust gas, and controlled by controlling the flow rate of the flushing water entering the temperature and humidity regulator.

[0009] By adopting the above technical solution, the humidity and temperature in the temperature and humidity regulator can be controlled by controlling the flow rate of the flushing water, which facilitates the treatment of exhaust gas. This control method is simpler and easier, and it can also control the concentration of hydrofluoric acid produced, making it easier to produce hydrofluoric acid products of different concentrations.

[0010] Optionally, in step b, the condenser is a shell-and-tube condenser, and the exhaust gas is indirectly cooled by cooling water to 35-40°C.

[0011] By adopting the above technical solution, the shell-and-tube condenser can prevent the cooling water in the condenser from coming into contact with water mist and exhaust gas, thus preventing the cooling water from being polluted. The cooling water can be recycled. At the same time, the cooling water not coming into contact with water mist can also reduce the fluoride content dissolved in the water mist, thereby ensuring that the concentration of the condensed hydrofluoric acid is not affected.

[0012] Optionally, the temperature and humidity regulator in step a includes a housing and an atomizing device and an air jet device disposed within the housing, with the atomizing device connected to the water inlet pipe of the temperature and humidity regulator; The air intake pipes of the jet device and the temperature and humidity regulator are connected, and the jet device is located below the atomizing device; The jet device includes multiple air ducts and multiple jet pipes opened on the air ducts, with the jet pipes facing upwards; A vertical shaft is installed inside the jet pipe. The vertical shaft is rotatably connected to the air guide pipe, and the upper end of the vertical shaft protrudes from the jet pipe. The peripheral wall of the vertical shaft fits into the inner wall of the jet pipe, and multiple vertical grooves are opened on the peripheral wall of the vertical shaft. Multiple drive plates are fixedly connected to the circumferential wall inside the air guide pipe. The drive plates are evenly distributed around the axis of the vertical shaft, and the exhaust gas can drive the vertical shaft to rotate through the drive plates.

[0013] By adopting the above technical solution, the atomizing device can turn the pure water entering the temperature and humidity regulator into water mist, thereby dissolving the waste gas in the pure water. The vertical shaft in the jet device can rotate, and there are vertical grooves on the vertical shaft. The waste gas is sprayed out from the vertical grooves. At the same time, the waste gas can drive the vertical shaft to rotate, so that the waste gas can be dispersed in all directions as it is sprayed out, instead of gathering and rising together. The dispersed waste gas is also more likely to come into contact with the water mist, which facilitates the dissolution of fluorine gas in the pure water. Furthermore, the contact area between the dispersed waste gas and the water mist is larger, which facilitates the cooling of the waste gas by the water mist.

[0014] Optionally, the air duct is also filled with a filling block, which can fill the inside of the air duct so that the exhaust gas can only blow on the drive plate on one side of the vertical axis.

[0015] By adopting the above technical solution, the presence of the filling block can fill the inside of the air guide pipe, change the shape inside the air guide pipe, and make the exhaust gas flow only along one side of the inside of the air guide pipe. As a result, the exhaust gas can only impact the drive plate on one side. Thus, the drive plate of the vertical shaft is only subjected to force on one side and not on the other side, so the exhaust gas can drive the vertical shaft to rotate.

[0016] Optionally, a baffle is fixed at the upper end of the vertical shaft, which can block the jet pipe. The baffle is curved upwards around its perimeter, forming an inverted umbrella-shaped structure. A ring-shaped plate is fixedly connected to the four edges of the baffle, and the ring-shaped plate has dense, fine mesh.

[0017] By adopting the above technical solution, the atomizing device is located above the jetting device. Although the atomizing device sprays water mist, some water vapor will still fall, which can easily lead to water vapor entering the air duct and causing water accumulation in the air duct. Therefore, a baffle is installed. The baffle can block the air duct directly above the jetting device, making it difficult for water vapor to enter the air duct and reducing the probability of water accumulation in the air duct, so that the introduction of exhaust gas will not be affected. The baffle is raised around the edges, which can cause water droplets falling on the baffle to gather towards the center of the top of the baffle and not flow down the baffle, reducing the probability of water vapor falling. The baffle can rotate with the vertical axis, so the baffle can throw the water droplets off during the rotation, and water vapor will not accumulate on the baffle. At the same time, the annular plate on the baffle has fine mesh, so the water droplets will be decomposed into finer water droplets during the process of being thrown out, so that the water droplets form a water mist-like state, which facilitates the combination of water droplets and fluorine gas in exhaust gas.

[0018] Optionally, the atomizing device includes a plurality of horizontally arranged conduits and a plurality of atomizing nozzles fixedly connected to the conduits; The housing is equipped with an adjustment device that allows the guide tube to move up and down to adjust the distance between the atomizing device and the jetting device.

[0019] By adopting the above technical solution, the water vapor and exhaust gas sprayed by the atomizing device and the jetting device reach their maximum area at a certain distance, and gradually decrease at a greater distance. Therefore, the distance between the atomizing device and the jetting device can be adjusted by the regulating device, so that the water vapor and exhaust gas merge when they diffuse to the maximum distance, which facilitates the dissolution of fluorine gas in the water vapor, improves the removal rate of fluorine gas in the exhaust gas by the atomizing device, and at the same time, the maximum contact area also enables the water mist to have the best cooling effect on the exhaust gas for a longer time.

[0020] Optionally, the adjusting device includes two movable plates, which are located at both ends of the conduit to support the conduit. The two ends of the movable plate are fixedly connected to wedge-shaped sliders, and vertical wedge-shaped grooves are opened on the inner wall of the housing. The sliders and grooves slide together. A vertical adjusting rod is fixedly connected to the movable plate. The adjusting rod extends vertically upward through the top wall of the housing and protrudes onto the upper surface.

[0021] By adopting the above technical solution, the moving plate can be driven to move up and down by the adjusting rod. At the same time, the moving plate and the duct are fixedly connected. The up and down movement of the moving plate can achieve the purpose of controlling the height of the atomizing device. Therefore, the distance between the atomizing device and the jetting device can be adjusted to maximize the contact area between the exhaust gas and the water mist, improve the removal effect of fluorine gas, and enhance the cooling effect of the water mist on the exhaust gas.

[0022] Optionally, the portion of the adjusting rod protruding from the upper surface of the housing is fitted with a fixing sleeve, which is fixedly connected to the surface of the housing. A fixing bolt is threaded onto the fixing sleeve, and the end of the fixing bolt extends into the fixing sleeve and abuts against the surface of the adjusting rod.

[0023] By adopting the above technical solution, when it is necessary to adjust the height of the moving plate, loosen the fixing bolts, and then drive the adjusting rod to move up and down in the fixing sleeve. The movement of the adjusting rod can drive the moving plate to move. After the moving plate is adjusted to the appropriate position, tighten the fixing bolts. The fixing bolts abut against the surface of the adjusting rod, that is, fix the adjusting rod so that the adjusting rod cannot move, thereby fixing the moving plate.

[0024] Optionally, a return water pipe and an outlet water pipe are fixedly connected to the washing tower. A circulation pump is fixedly connected to the end of the return water pipe away from the cooling tower, and the outlet water pipe is also fixedly connected to the circulation pump. The inlet and outlet pipes of the temperature and humidity regulator are connected.

[0025] By adopting the above technical solution, the scrubbing tower is used to further wash the waste gas, washing away the fluorine gas in the waste gas and minimizing the fluorine content in the waste gas to facilitate further treatment of the waste gas. The fluorine gas dissolves in the cleaning liquid of the scrubbing tower, which is pure water. At this time, the fluorine content in the pure water is very low and insufficient to form hydrofluoric acid. Therefore, the fluorine-containing cleaning liquid is sent to the temperature and humidity regulator to become water mist to remove the fluorine gas in the waste gas. This allows the water vapor entering the condenser to have a high fluorine content. After the water vapor condenses, the fluorine content can reach 90%, which in turn forms hydrofluoric acid, making the hydrofluoric acid usable.

[0026] In summary, 1. Fluorine-containing waste gas can be treated through steps a, b, c, d, and e. Step a uses adiabatic evaporation to initially cool the waste gas and dissolve the fluorine in the waste gas into water mist, thus removing the fluorine. Step b cools the waste gas to 35-40°C, making it easier for the waste gas to enter subsequent processes for treatment. It also produces a high concentration of hydrofluoric acid, eliminating the need for subsequent concentration steps, making it more convenient and faster. Step c temporarily stores the hydrofluoric acid. Step d further cleans the waste gas to remove as much fluorine as possible. Step e allows for the reuse of rinsing water, preventing wastewater generation and making it more environmentally friendly and energy-saving. 2. The atomizing and jetting devices in the temperature and humidity regulator can turn the pure water entering the regulator into a water mist. The exhaust gas ejected by the jetting device comes into contact with the water mist to achieve adiabatic evaporation, thus cooling the exhaust gas. At the same time, the fluorine gas in the exhaust gas dissolves in the water mist to form HF. Then, the mixture of exhaust gas and water vapor enters the condenser for condensation. While cooling the exhaust gas, the HF condenses to form hydrofluoric acid, achieving the goal of directly recovering the fluorine gas in the exhaust gas into hydrofluoric acid, which is more energy-saving and environmentally friendly. 3. The scrubbing tower can further clean the fluorine gas in the waste gas, minimizing its content and facilitating subsequent waste gas treatment. This results in the scrubbing liquid (pure water) containing a certain amount of fluorine, which is then atomized in a temperature and humidity regulator to treat the fluorine gas in the waste gas. This increases the fluorine content in the water vapor, ensuring that the fluorine content in the hydrofluoric acid condensed in the condenser is sufficiently high, allowing the hydrofluoric acid to be used directly. Attached Figure Description

[0027] Figure 1 This is a system diagram of the processing system in the embodiment.

[0028] Figure 2 This is a schematic diagram of the overall structure of the temperature and humidity regulator in the embodiment.

[0029] Figure 3 This is a cross-sectional view highlighting the internal structure of the temperature and humidity regulator in the embodiment.

[0030] Figure 4 yes Figure 3 Enlarged view of section A.

[0031] Figure 5 This is a schematic diagram highlighting the jet head structure in an embodiment.

[0032] Figure 6 This is a cross-sectional view highlighting the infill block in the embodiment.

[0033] Explanation of reference numerals in the attached figures: 1. Temperature and humidity regulator; 11. Water inlet pipe; 12. Flow control valve; 13. Housing; 14. Air inlet pipe; 141. Corrugated pipe; 15. Connecting pipe; 2. Condenser; 3. Storage tank; 4. Scrubber; 41. Circulating pump; 42. Water outlet pipe; 43. Water return pipe; 5. Atomizing device; 51. Conduit; 52. Atomizing nozzle; 53. Moving plate; 531. Slider; 54. Adjusting rod; 55. Fixing sleeve; 56. Fixing bolt; 6. Jet device; 61. Air guide pipe; 62. Connecting plate; 63. Jet pipe; 7. Jet head; 71. Vertical shaft; 72. Drive plate; 73. Vertical groove; 74. Baffle; 75. Annular plate; 751. Mesh; 8. Filler block; 81. Groove; 82. Inclined surface. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0035] A process for directly recovering hydrofluoric acid from fluorine-containing waste gas includes the following steps: a. Fluorine-containing waste gas enters temperature and humidity regulator 1, where it is cooled down through adiabatic evaporation. At the same time, the fluorine in the waste gas dissolves in water and combines to form HF. b. The exhaust gas enters the condenser 2 to cool it down, and at the same time, it can condense HF into hydrofluoric acid. c. The exhaust gas enters the scrubbing tower 4 for rinsing, and the hydrofluoric acid enters the storage tank 3 for storage. d. After being washed by scrubbing tower 4, the waste gas is sent to the next process for treatment; e. The flushing liquid in the scrubbing tower 4 is pumped into the temperature and humidity regulator 1 by the circulating pump to form water mist.

[0036] The adiabatic evaporation in step a uses minimal water to achieve preliminary cooling of the waste gas, ensuring that the temperature of the waste gas entering condenser 2 is not too high. This allows condenser 2 to lower the waste gas temperature to 35-40°C. After the waste gas passes through scrubbing tower 4, its temperature returns to ambient level, facilitating subsequent treatment processes. Adiabatic evaporation also keeps the water mist largely dispersed, allowing fluorine in the waste gas to dissolve in the water mist, which then condenses to form a high-concentration hydrofluoric acid product.

[0037] In step a, the appropriate temperature and humidity are selected based on the required concentration of hydrofluoric acid and the composition of the exhaust gas. The flow rate of the flushing water entering the temperature and humidity regulator is controlled to control the degree of initial cooling of the exhaust gas and the fluorine content in the water mist, thereby controlling the concentration of the hydrofluoric acid product.

[0038] The process for directly recovering hydrofluoric acid from fluorine-containing waste gas also includes the following systems: A system for the direct recovery of hydrogen fluoride from fluorine-containing waste gas. (Refer to...) Figure 1 The treatment system includes a temperature and humidity regulator 1, a condenser 2, and a storage tank 3 connected in sequence. Fluorine-containing waste gas enters the temperature and humidity regulator 1, which contains water mist. The waste gas undergoes initial cooling through adiabatic evaporation in the regulator 1, raising its temperature to 50-80°C. Simultaneously, the fluorine in the waste gas dissolves in the water mist to form HF. The water mist then enters the condenser 2 for condensation and cooling, reducing the waste gas temperature to 35-40°C, facilitating subsequent treatment. The condenser also condenses the HF from a gaseous state to a liquid state, forming hydrofluoric acid. The hydrofluoric acid is temporarily stored in the storage tank 3. Once sufficient hydrofluoric acid has been stored, it is discharged from the storage tank 3 and transported away. This system directly recovers fluorine from waste gas into hydrofluoric acid, which can be used directly as a concentrated hydrofluoric acid product without being discharged as wastewater. Compared to existing treatment methods, this approach is more environmentally friendly and energy-efficient.

[0039] Reference Figure 1Condenser 2 is a shell-and-tube type condenser that uses reverse indirect cooling to cool the exhaust gas and condense HF to form hydrofluoric acid. The indirect cooling method prevents the cooling water from coming into contact with the exhaust gas, thus preventing the concentration of hydrofluoric acid from being affected by the cooling water. In addition, condenser 2 has separate cooling water supply and cooling water return loops, which prevents the exhaust gas from polluting the cooling water. The cooling water can also be recycled, reducing the waste of water resources.

[0040] The condenser 2 is also connected to a scrubbing tower 4. The exhaust gas in the condenser 2 is sent to the scrubbing tower 4 for washing. The scrubbing tower 4 can further remove the residual fluorine gas in the exhaust gas, so that the fluorine content in the exhaust gas is minimized, thus making it easier for the exhaust gas to be sent to the next process for treatment.

[0041] Reference Figure 1 A circulating pump 41 is installed on one side of the scrubbing tower 4. The circulating water of the scrubbing tower 4 enters the circulating pump 41 through the outlet pipe 42. The outlet of the circulating pump 41 is connected to the return pipe 43, which reintroduces the circulating water into the scrubbing tower 4 for rinsing. At the same time, the inlet pipe 11 of the temperature and humidity regulator 1 is also connected to the return pipe 43. The clean water that enters the temperature and humidity regulator 1 and turns into water mist is the rinsing water of the scrubbing tower 4. The rinsing water performs the final rinsing of the exhaust gas. Therefore, the rinsing water also contains fluoride, but the fluoride content is very low and not enough to form hydrofluoric acid. The fluoride-containing rinsing water is sent into the temperature and humidity regulator 1 to form water mist. The water mist in the temperature and humidity regulator 1 itself contains fluoride. When the fluoride gas initially enters the temperature and humidity regulator 1 and is mixed with the water mist, the fluoride content in the water mist will be higher, thus resulting in a higher concentration of hydrofluoric acid formed after the water mist condenses. The system continuously replenishes water to the scrubbing tower 4, ensuring that the fluoride concentration in the flushing water is not too high and that the flushing effect on the exhaust gas is not affected. The flushing water is then used in the temperature and humidity regulator 1, eliminating the need for discharge and reducing environmental pollution.

[0042] A flow control valve 12 is also fixed on the water inlet pipe 11 of the temperature and humidity regulator 1. The flow control valve 12 can control the flow rate of pure water entering the temperature and humidity regulator 1, thereby controlling the temperature and humidity in the temperature and humidity regulator 1. By controlling different temperatures and humidity, the concentration of hydrofluoric acid and the components in the exhaust gas can be controlled, which is more convenient and faster.

[0043] Reference Figure 2 and Figure 3The temperature and humidity regulator 1 includes a housing 13 and an atomizing device 5 and an atomizing device 6 disposed inside the housing 13. The atomizing device 5 is connected to a water inlet pipe 11, and an air inlet pipe 14 is connected to the housing 13 to send exhaust gas into the atomizing device 6. The atomizing device 5 is located above the atomizing device 6. The atomizing device 5 can turn the flushing water sent in by the water inlet pipe 11 into water mist, and the atomizing device 6 can spray out the exhaust gas, thereby facilitating the contact between the water mist and the exhaust gas, realizing the adiabatic evaporation of the exhaust gas, cooling the exhaust gas, and the fluorine gas in the exhaust gas can easily dissolve in the water mist.

[0044] Reference Figure 2 The lower end of the housing 13 is conical, and the lowest point is connected to a connecting pipe 15, which facilitates the connection between the temperature and humidity regulator 1 and the condenser 2. The conical bottom surface can reduce the accumulation of some water droplets formed by water mist inside the housing 13.

[0045] Reference Figure 3 The atomizing device 5 includes multiple conduits 51 and multiple atomizing nozzles 52. Each conduit 51 has multiple atomizing nozzles 52, and the atomizing nozzles 52 are evenly distributed along the length of the conduit 51. The multiple conduits 51 are evenly distributed in the transverse direction. The arrangement of multiple conduits 51 and multiple atomizing nozzles 52 enables the water mist to better fill the interior of the housing 13, and allows the water mist and exhaust gas to come into more comprehensive contact.

[0046] Reference Figure 3 Both ends of the conduit 51 are provided with movable plates 53. A wedge-shaped slider 531 is fixedly connected to the side of the movable plate 53 near the housing 13. A vertical wedge-shaped groove is opened on the side wall of the housing 13. The slider 531 and the groove cooperate to move the movable plate 53 up and down. The movable plate 53 is fixedly connected to all the conduits 51. Therefore, the movement of the movable plate 53 can drive the conduit 51 to move up and down, thereby controlling the distance between the atomizing device 5 and the jetting device 6. The water mist sprayed by the atomizing nozzle 52 has the largest dispersion area after reaching a certain distance. After exceeding this distance, it will attenuate under the action of gravity. Therefore, controlling the distance between the atomizing device 5 and the jetting device 6 can make the water mist disperse to the maximum area and merge with the exhaust gas, which is convenient for cooling the exhaust gas and also facilitates the dissolution of fluorine gas in the water mist.

[0047] Reference Figure 3 The end of the water inlet pipe 11 extends into the housing 13 and is bent upwards. A corrugated pipe 141 is fixedly connected to the end of the water inlet pipe 11. The upper end of the corrugated pipe 141 is fixedly connected to a movable plate 53. A water channel exists inside the movable plate 53, which connects the corrugated pipe 141 and all the conduits 51. The corrugated pipe 141 can extend and retract, so the up and down movement of the movable plate 53 will not affect the water supply from the water inlet pipe 11 to the conduits 51.

[0048] Reference Figure 3 and Figure 4A vertical adjusting rod 54 is fixedly connected to the movable plate 53. The adjusting rod 54 protrudes upward from the upper surface of the housing 13. A fixing sleeve 55 is fitted onto the protruding part of the adjusting rod 54. The fixing sleeve 55 is fixedly connected to the upper surface of the housing 13, and a fixing bolt 56 is threaded onto the fixing sleeve 55. The end of the fixing bolt 56 extends into the fixing sleeve 55 and abuts against the adjusting rod 54. The adjusting rod 54 can drive the movable plate 53 to move up and down, thereby driving the guide tube 51 to move. After moving to the appropriate position, the fixing bolt 56 is tightened to press the adjusting rod 54 against it, thereby fixing the movable plate 53.

[0049] Reference Figure 2 and Figure 3 The jetting device 6 includes multiple air guide pipes 61 and a connecting plate 62 located at one end of each air guide pipe 61. The air guide pipes 61 are located below the duct 51, and multiple jet heads 7 are fixedly connected to the upper part of the air guide pipes 61. The multiple jet heads 7 are evenly distributed along the length of the air guide pipes 61 and are positioned upwards. The jet heads 7 can spray exhaust gas, causing the exhaust gas to rise and mix with water mist. The cooperation of multiple air guide pipes 61 and jet heads 7 allows the exhaust gas to spread over a larger area inside the housing 13, thus facilitating the mixing of exhaust gas and water mist and achieving the purpose of cooling the exhaust gas through adiabatic evaporation.

[0050] Reference Figure 3 One end of all the air guide pipes 61 is fixedly connected to the connecting plate 62, and the air inlet pipe 14 is also fixedly connected to the connecting plate 62. The connecting plate 62 has an air passage inside, which can connect the air inlet pipe 14 and all the connecting plates 62, so that the air inlet pipe 14 can easily introduce exhaust gas into all the air guide pipes 61.

[0051] Reference Figure 5 and Figure 6Multiple jet pipes 63 are fixedly connected to the air duct 61, and the jet pipes 63 and the air duct 61 are connected. The jet head 7 includes a vertical shaft 71 and multiple drive plates 72 fixedly connected to the vertical shaft 71. The vertical shaft 71 is inserted into the jet pipe 63, and the circumferential surface of the vertical shaft 71 is in contact with the inner wall of the jet pipe 63. One end of the vertical shaft 71 protrudes from the jet pipe 63, and the other end of the vertical shaft 71 extends into the air duct 61. The vertical shaft 71 and the air duct 61 are rotatably connected, so that the vertical shaft 71 can rotate along its own axis. The drive plates 72 are fixedly connected to the part of the vertical shaft 71 located inside the air duct 61, and the multiple drive plates 72 are evenly distributed along the axis of the vertical shaft 71. The exhaust gas flows in the air duct 61 and impacts the drive plates 72, thereby driving the vertical shaft 71 to rotate through the drive plates 72. Multiple vertical grooves 73 are formed on the circumference of the vertical shaft 71. The vertical grooves 73 are evenly distributed around the vertical shaft 71. The exhaust gas can flow out from the vertical grooves 73. During the exhaust gas flow, the vertical shaft 71 is rotating, which makes it easier for the exhaust gas to disperse after it flows out, rather than maintaining a vertical upward state, making it easier for the exhaust gas to mix with water mist.

[0052] Reference Figure 5 A baffle 74 is fixedly connected to the upper end of the vertical shaft 71. The baffle 74 is an inverted umbrella shape, and a ring plate 75 is fixedly connected to the edge of the baffle 74. The axis of the ring plate 75 coincides with the axis of the vertical shaft 71. The ring plate 75 has densely distributed fine mesh 751. Because the exhaust gas rises and the water mist falls, the water mist will continue to fall after merging. Therefore, the baffle 74 is provided. The baffle 74 can prevent water mist from entering the air guide pipe 61 and avoid water accumulation in the air guide pipe 61. The inverted umbrella shape structure allows the water droplets formed by the water mist falling on the baffle 74 to fall off the baffle 74. Moreover, the baffle 74 can rotate with the vertical shaft 71, so it can fling the water droplets off the baffle 74. The baffle 74 with fine mesh 751 can decompose the flung water droplets, making the diameter of the water droplets smaller, so that the water droplets can reform into water mist, which facilitates the dissolution of fluorine gas in the exhaust gas into the water mist.

[0053] Reference Figure 6The vertical shaft 71 is located inside the air guide pipe 61 and is equipped with a filling block 8. The filling block 8 can fill two-thirds of the cross-section of the air guide pipe 61. The middle part of the filling block 8 has an arc-shaped groove 81. The groove 81 fits around the drive plate 72 and the drive plate 72 can rotate within the groove 81. The side walls of the filling block 8 on both sides of the groove 81 are inclined surfaces 82. The inclined surface 82 can be inclined from the end away from the groove 81 towards the center of the groove 81, so that the distance between the side wall of the filling block 8 near the groove 81 and the air guide pipe 61 is minimized, so that the flow of exhaust gas to the groove 81 is minimized, so that the impact force of the exhaust gas is greater and it is easier to drive the drive plate 72 to rotate. At the same time, because of the existence of the groove 81, the exhaust gas can only impact the drive plate 72 on one side of the vertical shaft 71, so that the drive plate 72 on the vertical shaft 71 is subjected to different forces, and thus the vertical shaft 71 is subjected to different forces, so that the vertical shaft 71 can rotate.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas, characterized in that: Includes the following steps: a. Fluorine-containing waste gas enters the temperature and humidity regulator (1), where it is cooled by adiabatic evaporation. At the same time, the fluorine in the waste gas dissolves in water and combines to form HF. b. The waste gas enters the condenser (2) to cool it down and condense the HF into hydrofluoric acid. c. The waste gas enters the scrubbing tower (4) for rinsing, and the hydrofluoric acid is stored in the storage tank (3). d. After being rinsed by the scrubbing tower (4), the waste gas is sent to the next process for treatment. e. The rinsing liquid in the scrubbing tower (4) is pumped into the temperature and humidity regulator (1) by the circulating pump (41) to form water mist. The temperature and humidity regulator (1) in step a includes a housing (13) and an atomizing device (5) and a jetting device (6) disposed within the housing (13). The atomizing device (5) is connected to the water inlet pipe (11) of the temperature and humidity regulator (1). The jetting device (6) is connected to the air inlet pipe (14) of the temperature and humidity regulator (1). The jetting device (6) is located below the atomizing device (5). The jetting device (6) includes multiple air guide pipes (61) and multiple jetting pipes (63) opened on the air guide pipes (61). The jetting pipes (63) are arranged facing upwards. 3) An internal vertical shaft (71) is provided, which is rotatably connected to the air guide pipe (61), and the upper end of the vertical shaft (71) protrudes from the jet pipe (63). The peripheral wall of the vertical shaft (71) and the inner wall of the jet pipe (63) are in contact. Multiple vertical grooves (73) are provided on the peripheral wall of the vertical shaft (71). Multiple drive plates (72) are fixedly connected to the peripheral wall of the vertical shaft (71) inside the air guide pipe (61). The drive plates (72) are evenly distributed around the axis of the vertical shaft (71). The exhaust gas can drive the vertical shaft (71) to rotate through the drive plates (72). A baffle (74) is fixed at the upper end of the vertical shaft (71), which can block the jet pipe (63); the baffle (74) is curved upward around its perimeter, forming an inverted umbrella-shaped structure; a ring plate (75) is fixedly connected around the perimeter of the baffle (74), and the ring plate (75) has dense and fine mesh (751) on it. A filling block (8) is also provided inside the air guide tube (61) at the vertical axis (71). The filling block (8) can fill two-thirds of the cross-section of the air guide tube (61). The middle part of the filling block (8) has an arc-shaped groove (81). The groove (81) fits around the drive plate (72). The drive plate (72) can rotate inside the groove (81). The side walls of the filling block (8) on both sides of the groove (81) are inclined surfaces (82). The end of the inclined surface (82) away from the groove (81) can be inclined towards the center of the groove (81), so that the distance between the side wall of the filling block (8) near the groove (81) and the air guide tube 61 is minimized. The flow of exhaust gas is minimized at the groove (81), resulting in a greater impact force and making it easier to drive the drive plate (72) to rotate. At the same time, due to the presence of the groove (81), the exhaust gas can only impact the drive plate (72) on one side of the vertical shaft (71), causing different forces on the drive plate (72) on the vertical shaft (71), which in turn causes different forces on the vertical shaft (71), thus enabling the vertical shaft (71) to rotate. In step a, the appropriate temperature and humidity are selected according to the required concentration of hydrofluoric acid and the composition of the exhaust gas, and the humidity and temperature in the temperature and humidity regulator are controlled by controlling the flow rate of the flushing water entering the temperature and humidity regulator (1).

2. The treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas according to claim 1, characterized in that: In step b, the condenser (2) is a shell-and-tube condenser (2), and the cooling water indirectly cools the exhaust gas to 35-40°C.

3. The treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas according to claim 1, characterized in that: The atomizing device (5) includes multiple horizontally arranged conduits (51) and multiple atomizing nozzles (52) fixedly connected to the conduits (51); the housing (13) is provided with an adjustment device, which can move the conduits (51) up and down to adjust the distance between the atomizing device (5) and the jet device (6).

4. The process for directly recovering hydrofluoric acid from fluorine-containing waste gas according to claim 3, characterized in that: The adjustment device includes two movable plates (53), which are located at both ends of the conduit (51) to support the conduit (51); wedge-shaped sliders (531) are fixedly connected to both ends of the movable plates (53), and vertical wedge-shaped grooves are opened on the inner wall of the housing (13), with the sliders (531) and the grooves sliding together; a vertical adjustment rod (54) is fixedly connected to the movable plates (53), and the adjustment rod (54) extends vertically upward through the top wall of the housing (13) and protrudes from the upper surface of the housing.

5. The treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas according to claim 4, characterized in that: The portion of the adjusting rod (54) protruding from the upper surface of the housing (13) is fitted with a fixing sleeve (55). The fixing sleeve (55) is fixedly connected to the surface of the housing (13), and a fixing bolt (56) is threaded onto the fixing sleeve (55). The end of the fixing bolt (56) extends into the fixing sleeve (55) and abuts against the surface of the adjusting rod (54).

6. The treatment process for directly recovering hydrofluoric acid from fluorine-containing waste gas according to claim 1, characterized in that: The washing tower (4) is fixedly connected to a return water pipe (43) and an outlet water pipe (42). The end of the return water pipe (43) away from the cooling tower is fixedly connected to a circulation pump (41), and the outlet water pipe (42) is also fixedly connected to the circulation pump (41). The inlet water pipe (11) of the temperature and humidity regulator (1) is connected to the return water pipe (43).

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