Dust removal and cooling device for aluminum fluoride production

Abstract

The application discloses a dust removal and cooling device for aluminum fluoride production and relates to the technical field of tail gas treatment equipment. A heat exchange pipe is arranged in a waste heat recovery device. The heat exchange pipe comprises multiple horizontal sections arranged horizontally. Tail exhaust pipes are coaxially arranged outside the corresponding horizontal sections of the heat exchange pipe. A first fixing seat is coaxially arranged outside the horizontal sections. A flow guide assembly is arranged outside the first fixing seat. An inductive element capable of automatically extending and contracting according to temperature is arranged inside the first fixing seat. The inductive element can drive the flow guide assembly to close a ring-shaped heat exchange cavity when the inductive element contracts. A turbulence passage is arranged in the first fixing seat. Turbulence fan blades are rotatably connected to the tail flow end of the first fixing seat. A starting sliding block is axially slidably connected to the first fixing seat. The inductive element can contract and drive the starting sliding block to slide to open the turbulence passage when the inductive element senses temperature change. Meanwhile, the flow guide assembly closes the ring-shaped heat exchange cavity, so that the tail gas flows through the turbulence passage and drives the turbulence fan blades to rotate. The application has the effect of reducing corrosion of the heat exchange pipe.

Description

Technical Field

[0001] This application relates to the technical field of exhaust gas treatment equipment, and in particular to a dust removal and cooling device for aluminum fluoride production. Background Technology

[0002] Aluminum fluoride is an important inorganic compound, appearing as a white powder or crystals at room temperature. In the electrolytic aluminum process, the addition of aluminum fluoride significantly lowers the melting point of the electrolyte system, thereby substantially reducing energy consumption. Furthermore, aluminum fluoride optimizes the migration efficiency of ions in the electrolyte, improves the conductivity of the molten system, and further reduces the cell voltage, minimizing energy loss. In addition, aluminum fluoride serves as a flux or opacifier in the ceramics and glass industries to optimize melting performance. It also plays an auxiliary role in welding, catalysis, and other applications, making it an indispensable inorganic chemical raw material in industrial systems.

[0003] The mainstream processes for producing aluminum fluoride can be divided into three main categories: wet process, dry process, and fluorosilicic acid process. Among them, the dry process is widely used in high-end electrolytic aluminum and electronic-grade aluminum fluoride fields due to its high product purity, no wastewater discharge, and optimized energy consumption. The dry process involves directly reacting high-purity alumina or aluminum hydroxide with gaseous anhydrous hydrogen fluoride at high temperatures. The resulting aluminum fluoride powder, mixed with the exhaust gas, is discharged from the bottom of the reactor. Therefore, the exhaust gas from the dry process contains a large amount of unreacted alumina, some fine aluminum fluoride dust, excess unreacted anhydrous hydrogen fluoride gas, and water vapor. When using a waste heat recovery device to cool the exhaust gas, it is essential to ensure that the minimum wall temperature of the waste heat recovery device is higher than the acid dew point of the hydrogen fluoride gas. Once the acid dew point temperature is reached, the hydrogen fluoride gas and water vapor in the exhaust gas will combine to form hydrofluoric acid liquid, causing extremely severe corrosion to equipment and pipelines. During operation or start-up and shutdown under low-load conditions such as small flue gas volume and low temperature, it is difficult to maintain the temperature at the tail end (i.e., cold end) of conventional waste heat recovery devices above the safe range. Corrosion products (such as sulfates and fluorides) are highly adhesive and combine with dust in the exhaust gas to form hard, sticky, acidic wet ash. Over time, this wet ash is not only difficult to remove, but it can also coat the metal surface of the heat exchange pipes, thus accelerating equipment damage.

[0004] Conventional waste heat recovery devices are typical high-inertia temperature control systems. The time for heat exchange between the regulated cold source and the flue gas is relatively delayed. Therefore, when the internal temperature of the device drops to the acid dew point, it is difficult to respond quickly and make timely adjustments. Over time, the internal pipes of the equipment are easily corroded by the gas, and the pipe walls are also prone to dust accumulation, which seriously affects the subsequent heat exchange efficiency. Summary of the Invention

[0005] In order to improve the situation where conventional waste heat recovery devices cannot respond in time to changes in exhaust gas conditions, resulting in internal pipe corrosion and ash accumulation, this application provides a dust removal and cooling device for aluminum fluoride production.

[0006] This application provides a dust removal and cooling device for aluminum fluoride production, which adopts the following technical solution:

[0007] A dust removal and cooling device for aluminum fluoride production includes, in sequence, a cyclone dust collector, a waste heat recovery unit, and a bag filter connected by pipes. The waste heat recovery unit is equipped with heat exchange tubes, which are arranged in a serpentine manner in the vertical direction. The heat exchange tubes include multiple horizontally placed sections. Tail pipes are coaxially sleeved on the outside of each horizontal section of the heat exchange tube to form a closed annular heat exchange cavity outside the heat exchange tubes. The multiple tail pipes are connected by pipes.

[0008] A first fixed seat is coaxially sleeved outside the horizontal section. A flow-guiding component is correspondingly arranged outside the first fixed seat. A sensor that can automatically expand and contract according to temperature is arranged inside the first fixed seat. The contraction of the sensor can drive the flow-guiding component to close the annular heat exchange cavity corresponding to the first fixed seat. A turbulence channel is opened at one end of the first fixed seat. The turbulence channel connects the outer wall of the first fixed seat and the annular heat exchange cavity corresponding to the tail end. A turbulence fan blade is rotatably connected to one side of the first fixed seat at the tail end. A starting slider that can open and close the turbulence channel is slidably connected inside the first fixed seat. One end of the sensor is connected to the starting slider so that it can open the turbulence channel by contracting itself and driving the starting slider to slide. At the same time, the flow-guiding component closes the annular heat exchange cavity so that the tail air flows through the turbulence channel and drives the turbulence fan blade to rotate.

[0009] Optionally, the inner wall of the first fixed base has multiple sensing channels spaced apart along the circumferential direction of the horizontal segment. Each sensing channel is opened through the horizontal segment axis. The sensing elements are distributed in each sensing channel along the horizontal segment axis. One end of the sensing element is connected to the first fixed base, and the other end is connected to the end of the starting slider away from the turbulence fan blade. The turbulence channel and the sensing channel correspond one-to-one.

[0010] Optionally, a flow-guiding ring is provided at the tail end of the first fixed seat. The outer wall of the flow-guiding ring is flush with the outer wall of the first fixed seat. Along the axial direction of the horizontal section and away from the flow-facing end of the first fixed seat, the distance between the flow-guiding ring and the outer wall of the horizontal section gradually decreases. The turbulence-disrupting fan blade is located inside the cavity enclosed by the flow-guiding ring. A mounting seat is fitted on the horizontal section corresponding to the position of the turbulence-disrupting fan blade. The turbulence-disrupting fan blade is rotatably connected to the outer wall of the mounting seat. Along the radial direction of the horizontal section, the outer diameter of the mounting seat is larger than the inner diameter of the horizontal section corresponding to the sensing channel. The opening of the turbulence-disrupting channel at the tail end of the first fixed seat faces the turbulence-disrupting fan blade.

[0011] Optionally, a scraper is provided on the side of the mounting base away from the wake end of the first fixed base. The scraper is close to the outer wall of the horizontal section and extends along the axial direction of the horizontal section. One end of the scraper is connected to the turbulence fan blade, and the other end of the scraper is provided with a limiting ring. The limiting ring is sleeved on the outside of the horizontal section, and one end of the scraper is inserted into the limiting ring and slidably connected with the limiting ring, so that the scraper can scrape the outer wall of the horizontal section when it rotates with the turbulence fan blade.

[0012] Optionally, a sealing ring is provided between the scraper and the mounting base. A striking block is provided inside the sealing ring. One end of the striking block near the scraper is a free end, and the other end is rotatably connected to the inner wall of the sealing ring. The axis of rotation is parallel to the axial direction of the horizontal section. One end of the scraper is inserted into the sealing ring and connected to the turbulence fan blade through a coupling ring. A vibrating plate is provided on the coupling ring. When the vibrating plate rotates with the turbulence fan blade, the striking block can strike the vibrating plate to make the vibrating plate vibrate.

[0013] Optionally, the scraper is provided with a plurality of flow-disrupting holes circumferentially through the horizontal section, and the plurality of flow-disrupting holes are distributed at intervals along the axial direction of the horizontal section.

[0014] Optionally, a second fixed seat is coaxially surrounding the first fixed seat, with a distance between the second fixed seat and the first fixed seat. The flow-guiding component is correspondingly and movably disposed between the first fixed seat and the second fixed seat. The outer wall of the second fixed seat contacts the inner wall of the tailpipe. The second fixed seat includes a flow-incoming ring and a flow-out ring. The flow-incoming surface of the inner ring of the flow-incoming ring is a smoothly transitioned curved surface. The inner diameter of the flow-incoming ring is equal to the maximum inner diameter of the flow-out ring. Along the axial direction of the horizontal segment and from the flow-incoming ring to the flow-out ring, the inner diameter of the flow-out ring gradually decreases.

[0015] Optionally, the diversion assembly includes a diversion plate, wherein multiple diversion plates are provided and are circumferentially spaced around the inner wall of the second fixed seat. One end of the diversion plate is rotatably connected to the maximum inner diameter of the wake ring, and the rotation axis is perpendicular to the axis of the horizontal segment. The other end of the diversion plate is a free end. A first return element is provided at the end of the diversion plate rotatably connected to the wake ring to maintain the initial state of the diversion plate tightly attached to the inner wall of the wake ring. The end of the diversion plate away from the incoming flow ring is connected to the starting slider through a connecting rod.

[0016] The diversion plate is an arc-shaped plate. When the free ends of all the diversion plates are in contact with the outer wall of the first fixed seat, the side walls of every two adjacent diversion plates are in contact to close the annular heat exchange cavity between the first fixed seat and the second fixed seat. At this time, the distance between the opening of the turbulence channel on the outer wall of the first fixed seat and the flow-facing end of the first fixed seat is less than the distance between the free end of the diversion plate and the flow-facing end of the first fixed seat.

[0017] Optionally, the wake ring is provided with a swinging spoiler on the side wall away from the front ring. One end of the swinging spoiler is rotatably connected to the position with the smallest inner diameter of the wake ring, and the other end is a free end.

[0018] Optionally, a support rod is provided between the first fixed seat and the second fixed seat, and the support rod is used to connect the first fixed seat and the second fixed seat into a whole.

[0019] In summary, this application includes at least one of the following beneficial effects:

[0020] 1. By installing a tailpipe outside the heat exchange tube, an annular heat exchange cavity for heat exchange is formed between the heat exchange tube and the tailpipe. A second fixing seat is installed on the outer ring of this annular heat exchange cavity. The second fixing seat includes a flow-facing ring and a tailpipe ring. The flow-facing surface of the inner ring of the flow-facing ring is a smoothly transitioned curved surface. The inner diameter of the flow-facing ring is equal to the maximum inner diameter of the tailpipe ring. Along the axial direction of the horizontal section and from the flow-facing ring to the tailpipe ring, the inner diameter of the tailpipe ring gradually decreases. That is, along the flow direction of the exhaust gas to be cooled, the inner diameter of the tailpipe ring gradually decreases, that is, the area of ​​the annular cavity formed by the tailpipe ring and the first fixing seat gradually decreases. Therefore, the exhaust gas will be passively accelerated when flowing through the tailpipe ring area. The tailpipe ring can actively guide the exhaust gas to flow towards the outer wall of the heat exchange tube, leading all the exhaust gas to the outer wall area of ​​the heat exchange tube. The exhaust gas that was originally far from the outer wall of the heat exchange tube will come close to the outer wall of the heat exchange tube after passing through the tailpipe ring, so that the exhaust gas can fully exchange heat with the outer wall of the heat exchange tube.

[0021] 2. When the exhaust gas flow rate decreases or the initial temperature of the exhaust gas drops, it will affect the final temperature exiting the annular heat exchanger cavity. The sensing element is positioned close to the outer wall of the heat exchange tube, enabling real-time monitoring of the temperature of the outer wall of the heat exchange tube and the exhaust gas flowing close to it. When the temperature in this area drops to the phase change temperature of the sensing element, the sensing element contracts. During this contraction, the sensing element drives the starting slider to slide. After the starting slider slides, it opens the turbulence channel. Simultaneously, the starting slider pulls the free end of the corresponding guide plate to swing through the connecting rod until the free end of the guide plate is close to the outer wall of the first fixed seat. At this point, all two... The sidewalls of two adjacent diversion plates are tightly attached to each other, thus sealing the corresponding annular cavity between the first and second fixed seats. Therefore, all exhaust gas is accelerated through the turbulence channel and blown toward the turbulence fan blades. The turbulence fan blades are driven to rotate by the accelerated tail flow, which disturbs the accelerated tail flow and breaks the laminar flow of the exhaust gas in the area close to the outer wall of the heat exchange tube. This fully promotes the heat exchange between the tail flow and the heat exchange tube, and improves the heat exchange rate between the exhaust gas and the refrigerant. After the tail flow is accelerated, it will be discharged from the annular heat exchange cavity more quickly, thereby reducing the residence time of the exhaust gas in the tailpipe and preventing the exhaust gas, which has already dropped in temperature, from dropping further.

[0022] 3. By installing a scraper after the turbulence fan blades, the scraper can rotate along with the turbulence fan blades. As the exhaust gas temperature decreases, acidic substances that corrode the outer wall of the heat exchange tube may be released. These acidic substances will leave corrosion residue on the outer wall of the heat exchange tube after corroding, which will hinder the heat exchange rate between the exhaust gas and the refrigerant inside the heat exchange tube. The rotating scraper can rotate and scrape away the dust and corrosion residue on the outer wall of the heat exchange tube, keeping the outer wall of the heat exchange tube clean. At the same time, the rotation of the scraper will drive the vibration plate to rotate. When the vibration plate rotates, it will hit the striking block. At this time, the vibration plate will generate vibration. The vibration plate will transmit the vibration generated by the impact to the scraper, so that the scraper will vibrate while rotating. The vibrating scraper is more effective in removing the dust and corrosion residue scraped off the outer wall of the heat exchange tube. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the dust removal and cooling device shown in Embodiment 1 of this application;

[0024] Figure 2 This is a cross-sectional schematic diagram of the interior of the waste heat recovery unit shown in Embodiment 1 of this application;

[0025] Figure 3 This is a structural schematic diagram illustrating the positions of the first and second fixing seats in Embodiment 1 of this application;

[0026] Figure 4 This is a partial cross-sectional schematic diagram illustrating the operating principle of the starting slider in Embodiment 1 of this application;

[0027] Figure 5 This is a partial cross-sectional schematic diagram illustrating the operating principle of the drainage plate in Embodiment 1 of this application;

[0028] Figure 6 yes Figure 4 An enlarged view at point A;

[0029] Figure 7 yes Figure 6 Schematic diagram of cross-section at BB.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Cyclone dust collector;

[0032] 2. Waste heat recovery unit; 21. Heat exchange tube; 211. Horizontal section; 212. Bending section; 22. Tail stack; 23. Annular heat exchange chamber;

[0033] 3. Baghouse dust collector;

[0034] 4. First fixed base; 41. Sensing channel; 42. Sensing element; 43. Starting slider; 44. Fixed rod; 45. Turbulence channel; 451. Turbulence inlet; 452. Turbulence outlet; 46. Drainage ring;

[0035] 5. Second fixed base; 51. Flow ring; 52. Wake ring; 53. Swinging spoiler; 54. Drain plate; 55. First recovery component;

[0036] 6. Support rod;

[0037] 7. Connecting rod;

[0038] 8. Turbidity fan blades; 81. Mounting base; 82. Sealing ring; 821. Impact block;

[0039] 9. Scraper; 91. Limiting ring; 92. Reinforcing scraper; 93. Coupling ring; 94. Vibrating plate; 95. Pushing block; 96. Flow disturbance hole. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0041] In the dry process for producing aluminum fluoride, high-purity alumina or aluminum hydroxide reacts directly with gaseous anhydrous hydrogen fluoride at high temperatures. The resulting aluminum fluoride powder, mixed with the exhaust gas, is discharged from the bottom of the reactor. Therefore, the exhaust gas from the dry process contains a large amount of unreacted alumina, some fine aluminum fluoride dust, excess unreacted anhydrous hydrogen fluoride gas, and water vapor. To protect the environment and save costs, the effective components in the exhaust gas are typically recovered, primarily alumina, fine aluminum fluoride dust, and anhydrous hydrogen fluoride gas. Simultaneously, a waste heat recovery device is used to cool the exhaust gas while recovering its residual heat.

[0042] Conventional waste heat recovery devices must ensure that the lowest internal wall temperature is higher than the acid dew point temperature (140°C) of hydrogen fluoride gas when cooling exhaust gas. This is because once the acid dew point temperature is reached, the hydrogen fluoride gas in the exhaust gas will combine with water vapor to form hydrofluoric acid, which will cause extremely severe corrosion to the equipment and pipelines. This is especially true at the tail end of the waste heat recovery device, where the exhaust gas has already undergone a long cooling path, resulting in the lowest temperature at the end. This is particularly problematic during low-load operation (i.e., low exhaust gas volume and low temperature) or during start-up and shutdown processes, where it is difficult to maintain the tail end temperature of conventional waste heat recovery devices above the safe range.

[0043] Conventional waste heat recovery devices are typical high-inertia temperature control systems. The time between the cold source and the flue gas heat exchange is relatively lagging. Therefore, when the internal temperature of the device (such as the pipe wall of the heat exchange pipe) drops to the acid dew point, the waste heat recovery device has difficulty to adapt and adjust in time. Over time, the internal pipes of the equipment are easily corroded by the gas, and the pipe walls are also prone to dust accumulation, which seriously affects the subsequent heat exchange efficiency. Example 1

[0044] Embodiment 1 of this application discloses a dust removal and cooling device for aluminum fluoride production, see reference... Figure 1 and Figure 2 The dust removal and cooling device for aluminum fluoride production includes a cyclone dust collector 1, a waste heat recovery unit 2, and a bag filter 3 connected by pipes. The cyclone dust collector 1 is used to receive the tail gas output from the dry process reactor. The tail gas then passes through the waste heat recovery unit 2 and the bag filter 3 through pipes and is finally discharged.

[0045] In some implementations, the cyclone dust collector 1 and the bag filter 3 can be selected from commercially available, mature products. For example, the cyclone dust collector 1 can be a conventional high-temperature cyclone dust collector 1, because the exhaust gas temperature after passing through the cyclone dust collector 1 is the highest, typically reaching 400-600℃, so a model capable of withstanding high temperatures needs to be selected. The exhaust gas undergoes coarse particle removal within the cyclone dust collector 1, performing preliminary purification and recovering alumina powder from the exhaust gas. The temperature of the exhaust gas discharged from the cyclone dust collector 1 is approximately in the range of 400-550℃. Subsequently, the exhaust gas enters the waste heat recovery unit 2 for cooling. The high-temperature exhaust gas gradually exchanges heat with the refrigerant, reducing the exhaust gas temperature to a suitable operating temperature for the bag filter 3, typically between 150-200℃. The bag filter 3 primarily focuses on efficiently capturing remaining fine dust, ensuring the dust concentration in the exhaust gas meets emission standards. It can also recover aluminum fluoride powder from the exhaust gas; this recovered aluminum fluoride powder is of high purity and can be used as a finished product or returned to the system. The functions and structures of the cyclone dust collector 1 and the bag filter 3 are identical to those of conventional products on the market and will not be elaborated upon here.

[0046] For example, the waste heat recovery unit 2 includes a hollow outer shell, inside which multiple heat exchange tubes 21 are fixed. In this embodiment, the number of heat exchange tubes 21 is preferably three, which are arranged side by side and spaced apart inside the shell. Each heat exchange tube 21 is arranged in a serpentine pattern in the vertical direction, and its upper and lower ends extend out of the shell. The heat exchange tubes 21 are used to introduce a refrigerant, such as water at a low temperature. The top opening of the heat exchange tube 21 is the refrigerant inlet, and the bottom opening is the refrigerant outlet, meaning that the refrigerant flows from top to bottom through the heat exchange tubes 21.

[0047] In some embodiments, each heat exchange tube 21 includes a horizontally placed and parallel horizontal section 211 and a curved section 212 connecting the horizontal section 211. A tailpipe 22 is coaxially and sealed around the corresponding horizontal section 211 of each heat exchange tube 21. The tailpipe 22 and the corresponding horizontal section 211 of the heat exchange tube 21 form a closed annular heat exchange chamber 23. Multiple tailpipe sections 22 on the same heat exchange tube 21 are interconnected vertically via pipes, resulting in a serpentine arrangement of the tailpipes 22 on the same heat exchange tube 21 from top to bottom. The top opening of the heat exchange tube 21 is connected to the outlet of the cyclone dust collector 1 via a pipe, and the bottom opening of the heat exchange tube 21 is connected to the inlet of the bag filter 3 via a pipe. The exhaust gas discharged from the cyclone dust collector 1 passes through the annular heat exchange chamber 23 from top to bottom. When the high-temperature exhaust gas flows through the annular heat exchange chamber 23, it can exchange heat with the refrigerant flowing in the opposite direction in the heat exchange tube 21 through the tube wall of the heat exchange tube 21, thereby reducing the temperature of the exhaust gas to the target temperature. Temperature sensors for monitoring temperature can be installed at both the inlet and outlet of the annular heat exchange chamber 23 of the waste heat recovery unit 2 to provide real-time feedback on the inlet and outlet temperatures of the exhaust gas.

[0048] For example, refer to Figures 2 to 5 Within the waste heat recovery unit 2, a first fixed seat 4 and a second fixed seat 5 are respectively installed in the annular heat exchange chamber 23 at the top. The first fixed seat 4 is coaxially sleeved and fixed to the outer wall of the horizontal section 211, and the second fixed seat 5 is correspondingly coaxially surrounding the first fixed seat 4, with a distance between them. Multiple support rods 6 are arranged between the first fixed seat 4 and the second fixed seat 5, spaced apart and radiating outwards along the circumference of the horizontal section 211. The length direction of the support rods 6 is consistent with the radial direction of the horizontal section 211. One end of each support rod 6 is fixed to the outer wall of the first fixed seat 4, and the other end is fixed to the inner wall of the second fixed seat 5. The support rods 6 connect the first fixed seat 4 and the second fixed seat 5 into a whole. The outer wall of the second fixed seat 5 is in close contact with the inner wall of the tailpipe 22.

[0049] In some embodiments, for ease of installation, the support rod 6 can be a telescopic sleeve. An adjusting sleeve is fitted onto the telescopic joint of the support rod 6. The adjusting sleeve is rotatably connected to the outer rod of the support rod 6 with a larger inner diameter. The inner wall of the adjusting sleeve has internal threads, while the outer wall of the inner rod of the support rod 6 with a smaller inner diameter has external threads. The internal thread of the adjusting sleeve engages with the external thread on the outer wall of the inner rod of the support rod 6, allowing the length of the support rod 6 to be adjusted by rotating the adjusting sleeve. When the two fixed seats are moved to a suitable installation position, rotating the adjusting sleeve causes the first fixed seat 4 and the second fixed seat 5 to abut against the horizontal section 211 and the tailpipe 22 respectively, thereby fixing the positions of the first fixed seat 4 and the second fixed seat 5. To further improve the stability of the first fixed seat 4 and the second fixed seat 5 during operation, anti-slip layers can be fixed on the inner wall of the first fixed seat 4 and the outer wall of the second fixed seat 5 respectively. The anti-slip layers can be made of materials with good high temperature resistance and corrosion resistance, such as ceramic materials like zirconium oxide. The natural rough or porous surface is formed by sintering, sandblasting, etching and other methods to provide good friction for fixing the first fixed seat 4 and the second fixed seat 5.

[0050] For example, the second fixed seat 5 includes a flow-incoming ring 51 and a tailflow ring 52. The flow-incoming surface of the inner ring of the flow-incoming ring 51 is a smoothly transitioned curved surface. Similarly, the flow-incoming end of the first fixed seat 4 is also a smoothly transitioned curved surface, making the exhaust gas flow more smoothly when passing through the first fixed seat 4 and the second fixed seat 5, and also reducing the flow impact force on the first fixed seat 4 and the second fixed seat 5. The inner diameter of the flow-incoming ring 51 is equal to the maximum inner diameter of the tailflow ring 52. Along the axial direction of the horizontal section 211 and from the flow-incoming ring 51 to the tailflow ring 52, the inner diameter of the tailflow ring 52 gradually decreases. At the minimum inner diameter of the tailflow ring 52, that is, at the end of the tailflow ring 52 away from the flow-incoming ring 51, there is also a distance between it and the outer wall of the first fixed seat 4, allowing the exhaust gas to pass through.

[0051] In some embodiments, the combination of the first fixing seat 4 and the second fixing seat 5 is installed at the tail position of the annular heat exchange cavity 23, that is, at the position of the top horizontal section 211 of the waste heat recovery unit 2. Multiple pairs of the combination of the first fixing seat 4 and the second fixing seat 5 are provided and are distributed at intervals along the axial direction of the horizontal section 211. The specific number of the combination of the first fixing seat 4 and the second fixing seat 5 can be determined according to the actual length of the horizontal section 211.

[0052] Under normal operating conditions, the intake temperature and volume of the exhaust gas are normal. When the exhaust gas exits the annular heat exchange chamber 23, its temperature is above the acid dew point. The hydrogen fluoride gas in the exhaust gas will not combine with water vapor to form an acidic liquid. The exhaust gas exchanges heat with the refrigerant within the annular heat exchange chamber 23. However, because the inner diameter of the tail ring 52 gradually decreases along the axial direction of the horizontal section 211 and from the upstream ring 51 to the tail ring 52, that is, along the flow direction of the exhaust gas to be cooled, the inner diameter of the tail ring 52... As the inner diameter gradually decreases, the area of ​​the annular cavity formed by the wake ring 52 and the first fixed seat 4 gradually decreases. Therefore, the exhaust gas is passively accelerated when flowing through the wake ring 52 region. Furthermore, the wake ring 52 can actively guide the exhaust gas towards the outer wall of the heat exchange tube 21, directing all the exhaust gas towards the outer wall region of the heat exchange tube 21. The exhaust gas that was originally far from the outer wall of the heat exchange tube 21 comes closer to the outer wall of the heat exchange tube 21 after passing through the wake ring 52, allowing the exhaust gas to fully exchange heat with the outer wall of the heat exchange tube 21. Since the combination of the first fixed seat 4 and the second fixed seat 5 is installed at the wake position of the annular heat exchange cavity 23, the flow cross-sectional area of ​​the exhaust gas decreases when it flows through the annular heat exchange cavity 23 corresponding to the first fixed seat 4 and the second fixed seat 5, and the flow velocity of the exhaust gas increases. This allows the exhaust gas to be discharged from the waste heat recovery unit 2 more quickly, reducing the residence time of the exhaust gas in the waste heat recovery unit 2 and avoiding acid corrosion due to the low velocity of the exhaust gas at the end.

[0053] In some embodiments, a swinging baffle 53 is provided on the side wall of the wake ring 52 away from the oncoming ring 51. One end of the swinging baffle 53 is rotatably connected to the position with the smallest inner diameter of the wake ring 52, and the other end is a free end. In this embodiment, three swinging baffles 53 are provided and are distributed at intervals in the upper half of the second fixed base 5. The free end of each swinging baffle 53 hangs down naturally to the annular area between the first fixed base 4 and the second fixed base 5 under its own weight. When the exhaust gas flows through this annular area, the exhaust gas will blow up the free end of the swinging baffle 53, causing the free end of the swinging baffle 53 to start swinging. A torsion spring can also be provided at the rotating end of the swinging baffle 53, so that the swinging baffle 53 swings back and forth under the drive of the exhaust gas. The swinging baffle 53 can disrupt the laminar flow state of the wake and form a more chaotic turbulent flow. The exhaust gas in the turbulent state can better exchange heat with the refrigerant.

[0054] For example, the inner wall of the first fixed base 4 has multiple sensing channels 41 spaced circumferentially along the horizontal segment 211. Each sensing channel 41 extends through the horizontal segment 211. In this embodiment, the number of sensing channels 41 is set to 6. Each sensing channel 41 of the first fixed base 4 is correspondingly provided with a sensing element 42. The sensing element 42 is made of shape memory alloy and can automatically expand and contract with temperature changes. To ensure that the phase transition temperature of the sensing element 42 is slightly higher than the acid dew point temperature of hydrogen fluoride (approximately 140°C), the phase transition temperature of the sensing element 42 is set to 145°C. Therefore, the sensing element 42 can be made of ternary or multi-element nickel-titanium based alloys, such as nickel-titanium-hafnium alloys, nickel-titanium-palladium alloys, etc. These alloy materials are mixed according to a certain composition ratio and then obtained through melting, hot working, heat treatment, and shaping, so that the sensing element 42 elongates when the temperature is higher than its own phase transition temperature and contracts when the ambient temperature is lower than its own phase transition temperature. The amount of expansion and contraction of the sensing element 42 may be limited in actual use. In order to increase the amount of expansion and contraction of the sensing element 42 due to temperature, the sensing element 42 can be used in conjunction with mechanical amplification structures such as lever structures or micro pulley blocks. Such mechanical amplification structures are existing technologies, and it is sufficient to select the structure that is easiest to implement. It will not be elaborated here.

[0055] Furthermore, an activation slider 43 is slidably connected inside the first fixed base 4 along the axial direction of the horizontal section 211. The activation slider 43 corresponds one-to-one with the sensing element 42. The sensing element 42 is located on the flow-facing side of the first fixed base 4, while the activation slider 43 is located on the side of the sensing element 42 away from the flow-facing side of the first fixed base 4. A fixed rod 44 is fixedly fixed inside the sensing channel 41 of the first fixed base 4. One end of the sensing element 42 is fixedly connected to the fixed rod 44, and the other end is fixedly connected to the activation slider 43. The sensing element 42 is close to the outer wall of the horizontal section 211, thereby enabling it to sense the actual temperature of the outer wall of the horizontal section 211 in real time. When the sensing element 42 extends or retracts itself, it can pull the activation slider 43 to slide back and forth inside the first fixed base 4.

[0056] For example, the first fixed base 4 has a turbulence channel 45 at one end of the tailflow, and the turbulence channel 45 corresponds one-to-one with the sensing channel 41. The turbulence channel 45 has a turbulence inlet 451 on the outer wall of the first fixed base 4 and a turbulence outlet 452 on the end wall of the tailflow end of the first fixed base 4. When the slider 43 reciprocates, it can block or open the turbulence inlet 451. It should be noted that the figure shows the positional relationship of the turbulence channel 45 and does not represent the actual size under actual working conditions. The actual opening size of the turbulence inlet 451 and the turbulence outlet 452 can be adjusted appropriately according to actual conditions. For example, the opening size of the turbulence inlet 451 and the turbulence outlet 452 can be appropriately increased so that the exhaust gas can pass smoothly through the turbulence channel 45 and not accumulate at the turbulence inlet 451.

[0057] Furthermore, a plurality of diversion plates 54 are circumferentially distributed in the annular space between the first fixed seat 4 and the second fixed seat 5. In this embodiment, the number of diversion plates 54 is set to 6, and each diversion plate 54 corresponds one-to-one with the starting slider 43. Therefore, there are also 6 starting sliders 43. Each starting slider 43 corresponds one-to-one with the sensing element 42, the turbulence channel 45, and the sensing channel 41. Therefore, there are 6 sensing elements 42, the turbulence channel 45, and the sensing channel 41. One end of the diversion plate 54 is rotatably connected to the maximum inner diameter of the wake ring 52, and the axis of rotation is perpendicular to the axis of the horizontal segment 211. The other end of the diversion plate 54 is a free end. A first return element 55 is provided at the end of the diversion plate 54 rotatably connected to the wake ring 52. The first return element 55 can preferably be a torsion spring. One end of the first return element 55 abuts against the wake ring 52, and the other end abuts against the diversion plate 54 to maintain the initial state of the diversion plate 54 tightly attached to the inner wall of the wake ring 52. The end of the diverting plate 54 furthest from the incoming flow ring 51 is connected to the starting slider 43 via a connecting rod 7. One end of the connecting rod 7 is hinged to the free end of the diverting plate 54, and the other end is hinged to the starting slider 43. The diverting plate 54 is an arc-shaped plate. When the free ends of all the diverting plates 54 are in contact with the outer wall of the first fixed seat 4, the side walls of every two adjacent diverting plates 54 are in contact, thereby sealing the annular heat exchange cavity 23 between the first fixed seat 4 and the second fixed seat 5. At this time, the distance between the turbulence inlet 451 of the turbulence channel 45 and the incoming flow end of the first fixed seat 4 is less than the distance between the free end of the diverting plate 54 and the incoming flow end of the first fixed seat 4.

[0058] In some embodiments, a turbulence-inducing fan blade 8 is rotatably connected to one side of the wake end of the first fixed base 4. The turbulence-inducing fan blade 8 is rotatably connected to the outer wall of the horizontal section 211 via a mounting base 81, which is fixedly sleeved on the outer wall of the horizontal section 211. The turbulence-inducing fan blade 8 is rotatably connected to the outer wall of the mounting base 81. The turbulence-inducing fan blade 8 is arranged around the outside of the horizontal section 211, and the turbulence outlet 452 of the turbulence channel 45 on the wake side of the first fixed base 4 faces the turbulence-inducing fan blade 8.

[0059] It is understandable that since the sensing channel 41 is opened on the inner wall of the first fixed seat 4, the sensing channel 41 is close to the outer wall of the horizontal section 211 of the heat exchange tube 21, and the sensing element 42 is located inside the sensing channel 41, so that the sensing element 42 can sense the temperature of the outer wall of the horizontal section 211 of the heat exchange tube 21 in real time. Alternatively, the sensing element 42 can also be directly close to the outer wall of the horizontal section 211, thereby directly sensing the temperature of the outer wall of the horizontal section 211. When the exhaust gas flow rate decreases or the initial temperature of the exhaust gas drops, it will affect the final temperature of the annular heat exchange chamber 23. Once the temperature of the exhaust gas in the tail section of the tailpipe 22 is lower than the phase change temperature of the sensing element 42, the sensing element 42 will be the first to sense it and contract itself. When the sensing element 42 contracts, it will drive the starting slider 43 to slide towards the flow-facing end of the first fixed seat 4, thereby opening the turbulence inlet 451 of the turbulence channel 45. At the same time, the starting slider 43 pulls the free end of the corresponding guide plate 54 through the connecting rod 7 to swing until the free end of the guide plate 54 is close to the outer wall of the first fixed seat 4. At this time, the side walls of all pairs of adjacent guide plates 54 are close to each other, thereby closing the corresponding annular cavity between the first fixed seat 4 and the second fixed seat 5. At this time, the exhaust gas that originally flowed through the annular cavity between the first fixed seat 4 and the second fixed seat 5 all enters the turbulence channel 45 through the turbulence inlet 451, and then sprays out from the turbulence outlet 452 of the turbulence channel 45 and sprays towards the turbulence fan blade 8, thereby driving the turbulence fan blade 8 to rotate.

[0060] In some embodiments, the actual size of the turbulence channel 45 can be adjusted according to actual conditions. For example, the actual guide cross-section of each turbulence channel 45 can be smaller, resulting in a significant increase in airflow velocity as the flow area decreases when passing through each turbulence channel 45. Simultaneously, the number of combinations of turbulence channels 45 with corresponding starting sliders 43 and sensors 42 can be appropriately increased, allowing exhaust gas to flow through multiple turbulence channels 45 simultaneously, forming multiple high-velocity exhaust gases that simultaneously impact the turbulence fan blade 8. This ensures that the accelerated exhaust gas has sufficient kinetic energy to drive the turbulence fan blade 8 to rotate. Furthermore, the turbulence fan blade 8 can preferably be an axial flow fan blade. This airfoil structure can generate efficient rotational torque under airflow action. Compared to simple flat blades, airfoil blades can generate greater driving force at lower airflow speeds. Meanwhile, the turbulence fan blade 8 can be preferably made of titanium alloy or aluminum alloy, which can greatly reduce the density of the turbulence fan blade 8, thereby greatly reducing the moment of inertia of the turbulence fan blade 8. The smaller the moment of inertia, the smaller the initial torque required to start the turbulence fan blade 8, thus ensuring that the turbulence fan blade 8 can always be driven to rotate by the airflow. This can directly reduce the critical speed for starting the turbulence fan blade 8 by a significant order of magnitude, allowing the turbulence fan blade 8 to be activated at a lower exhaust gas flow rate, thereby expanding its effective working range.

[0061] The high-temperature exhaust gas transfers heat to the cooler wall of the heat exchange tube 21. This process is mainly convective. When the exhaust flows over the outer wall of the heat exchange tube 21, due to the viscosity of the fluid, the velocity of the exhaust layer immediately adhering to the outer wall is zero. From the outer wall of the heat exchange tube 21 outwards, the velocity of the exhaust gas gradually increases until it reaches the mainstream velocity. This thin layer where the velocity changes drastically is called the velocity boundary layer. Similarly, the outer wall temperature of the heat exchange tube 21 is low, while the temperature of the mainstream exhaust gas is high. The fluid temperature immediately adhering to the outer wall of the heat exchange tube 21 is approximately equal to the wall temperature, gradually increasing outwards to the mainstream temperature. This thin layer where the temperature changes drastically is called the thermal boundary layer. Inside the thermal boundary layer, heat transfer mainly relies on conduction. However, gases have very poor thermal conductivity, so this thermal boundary layer acts like a "heat insulation suit," severely hindering the transfer of heat from the high-temperature exhaust gas in the mainstream region to the wall of the heat exchange tube 21. Under low-load conditions—when the exhaust gas flow rate is small and the inlet temperature is low—the temperature at the end of the exhaust gas flowing through the tailpipe 22 is already low. At lower exhaust gas velocities, the laminar flow formed on the outer wall of the horizontal section 211 becomes thicker and more stable, further hindering heat exchange between the exhaust gas and the heat exchange tube 21. This further reduces the temperature of the outer wall of the heat exchange tube 21, potentially reaching the acid dew point of hydrogen fluoride, causing corrosion of the outer wall. Even if the mainstream exhaust gas temperature remains relatively high, the inability to transfer heat causes the tube wall temperature to drop rapidly, falling below the acid dew point.

[0062] To prevent the outer wall temperature of heat exchange tube 21 from dropping to the acid dew point, all exhaust gas passes through turbulence channel 45. Since the cross-sectional area of ​​turbulence channel 45 is smaller than that of the annular heat exchange cavity 23, the exhaust gas velocity increases as it flows through turbulence channel 45. This increased velocity then impacts turbulence fan blades 8 as it exits turbulence channel 45. The rotating turbulence fan blades 8 further disrupt the accelerated exhaust gas, creating numerous downstream vortices of varying sizes. These intense vortices forcefully scour the tube wall of heat exchange tube 21, completely disrupting the original laminar flow and forcing the entire flow field into a highly turbulent state. The flow state is controlled to prevent the exhaust gas from forming a stable laminar flow on the outer wall of the heat exchange tube 21. This promotes the heat exchange rate between the exhaust gas and the outer wall of the heat exchange tube 21, allowing more heat to be transferred from the exhaust gas to the tube wall of the heat exchange tube 21, thereby causing the tube wall temperature to rise and eventually stabilize at a new equilibrium point higher than the acid dew point. This effectively prevents corrosion and dust accumulation on the outer wall of the heat exchange tube 21. Furthermore, once the end temperature of the exhaust gas drops, the entire adjustment process is carried out in real time and quickly. When the operating conditions return to normal, the entire adjustment system can be restored to its initial state through the autonomous expansion and contraction deformation of the sensing element 42.

[0063] In some embodiments, since the exhaust gas temperature is lowest at the end, the combination of the first fixing seat 4 and the second fixing seat 5 is arranged at the top horizontal section 211 of the waste heat recovery unit 2, and the number of the combination of the first fixing seat 4 and the second fixing seat 5 can be increased or decreased according to the actual length of the horizontal section 211.

[0064] In some embodiments, the tail end of the starting slider 43 near the first fixed base 4 has a wedge-shaped slope with gradually decreasing thickness. When the starting slider 43 is pulled by the sensing element 42 towards the oncoming end of the first fixed base 4, the wedge-shaped slope of the starting slider 43 can guide the tail gas flow towards the turbulence outlet 452. A sealing gasket is fixed on the outer wall of the starting slider 43. When the starting slider 43 closes the turbulence inlet 451, the sealing gasket can abut against the side wall of the first fixed base 4, improving the sealing performance of the turbulence inlet 451. Along the radial direction of the horizontal section 211, the thickness of the mounting base 81 of the turbulence fan blade 8 is greater than the height of the sensing channel 41, so that part of the tail gas flowing through the sensing channel 41 does not drive the turbulence fan blade 8 to rotate, or only drives the turbulence fan blade 8 to rotate slowly.

[0065] In some embodiments, a guide ring 46 is fixed to the tail end of the first fixed base 4. The outer wall of the guide ring 46 is flush with the outer wall of the first fixed base 4. Along the axial direction of the horizontal section 211 and away from the flow-facing end of the first fixed base 4, the distance between the inner wall of the guide ring 46 and the outer wall of the horizontal section 211 gradually decreases, so that the guide ring 46 forms an annular cavity around the outside of the horizontal section 211. The turbulence fan blade 8 is located inside the cavity formed by the guide ring 46, and the turbulence outlet 452 of the turbulence channel 45 is also located inside the annular cavity formed by the guide ring 46. The annular cavity formed by the guide ring 46 can guide all the exhaust gas accelerated from the turbulence outlet 452 to be concentrated and blown towards the turbulence fan blade 8, driving the turbulence fan blade 8 to rotate rapidly.

[0066] The implementation principle of the dust removal and cooling device for aluminum fluoride production in Embodiment 1 of this application is as follows: Under low load conditions, the exhaust gas flow rate is small and the temperature is low, especially the end temperature of the exhaust gas, which is even lower, causing the outer wall temperature of the heat exchange tube 21 at the end of the exhaust gas to decrease. To prevent the outer wall temperature of the heat exchange tube 21 from dropping to the acid dew point temperature of hydrogen fluoride, the sensing element 42 sets its own phase change temperature slightly higher than the acid dew point temperature. When the end temperature of the exhaust gas reaches or falls below the phase change temperature of the sensing element 42, the sensing element 42 retracts itself and pulls the starting slider 43 to slide. After the starting slider 43 slides, it opens the turbulence opening, and the starting slider 43 drives the corresponding diverting plate 54 to swing through the connecting rod 7 until all diverting plates... The free end of 54 contacts the outer wall of the first fixed seat 4, and the side walls of each pair of adjacent guide plates 54 contact each other, thereby sealing the annular ventilation cavity between the first fixed seat 4 and the second fixed seat 5. All exhaust gas is accelerated through the turbulence channel 45 and sprayed onto the turbulence fan blade 8, thereby driving the turbulence fan blade 8 to rotate. The rotating turbulence fan blade 8 can disrupt the laminar flow state of the exhaust gas and promote the heat exchange rate between the exhaust gas and the heat exchange tube 21. The exhaust gas further transfers its own heat to the outer wall of the heat exchange tube 21, so that the temperature of the outer wall of the heat exchange tube 21 is maintained above the acid dew point, thereby avoiding corrosion and dust accumulation on the outer wall of the heat exchange tube 21, and ensuring that the heat exchange tube 21 can continuously carry out a good heat exchange process with the exhaust gas. Example 2

[0067] The difference between Example 2 and Example 1 is that: (Refer to...) Figures 4 to 7 To further reduce the possibility of dust accumulation on the outer wall of the horizontal section 211, which could lead to a decrease in the heat exchange efficiency of the horizontal section 211, a scraper 9 is provided on the side of the mounting base 81 away from the tail end of the first fixed base 4.

[0068] For example, the scraper 9 is closely attached to the outer wall of the horizontal section 211 and extends along the axial direction of the horizontal section 211. In this embodiment, the number of scrapers 9 is set to two, and they are symmetrically distributed along the axis of the horizontal section 211. One end of the scraper 9 is connected to the turbulence fan blade 8, and the other end of the scraper 9 is provided with a limiting ring 91. The limiting ring 91 is sleeved on the outside of the horizontal section 211, and one end of the scraper 9 is inserted into the limiting ring 91 and slidably connected to the limiting ring 91. A reinforcing scraper strip 92 is fixed on the side of the scraper 9 near the outer wall of the horizontal section 211. The reinforcing scraper strip 92 is in direct contact with the outer wall of the horizontal section 211. The reinforcing scraper strip 92 can also be made of ceramic materials such as zirconium oxide, so that the reinforcing scraper strip 92 has good wear resistance.

[0069] Understandably, the scraper 9 can rotate synchronously with the turbulence fan blade 8. Under low load conditions, the outer wall of the horizontal section 211 may be corroded and accumulate dust. The rotating scraper 9 can scrape the outer wall of the horizontal section 211 to remove dust and other impurities that may remain on the tube wall due to corrosion, and keep the outer wall of the heat exchange tube 21 clean.

[0070] In some embodiments, a sealing ring 82 is provided between the scraper 9 and the mounting base 81. The sealing ring 82 is sleeved outside the horizontal section 211 and fixedly connected to the mounting base 81. The sealing ring 82 is hollow inside and is provided with a striking block 821. One end of the striking block 821 near the scraper 9 is a free end, and the other end is rotatably connected to the inner wall of the sealing ring 82. The axis of rotation is parallel to the axis of the horizontal section 211. A second return member is provided at the end of the striking block 821 that is hinged to the sealing ring 82. The second return member can also preferably be a torsion spring. One end of the second return member abuts against the striking block 821, and the other end abuts against the inner wall of the sealing ring 82. The second return member is used to drive the striking block 821 back to the initial vertical state. One end of the scraper 9 is inserted into the sealing ring 82 and is fixedly connected to the base of the turbulence fan blade 8 through the coupling ring 93. The coupling ring 93 is fixed with a vibrating plate 94 and a pushing block 95. Along the direction of rotation of the scraper 9, the pushing blocks 95 are spaced apart at the front end of the vibrating plate 94. When the vibrating plate 94 and the pushing block 95 rotate with the turbulence fan blade 8, the pushing block 95 first contacts the striking block 821 and pushes the striking block 821 to swing until the pushing block 95 disengages from the striking block 821. The striking block 821 swings in the opposite direction under the restoring force of the second restoring member. The swinging striking block 821 can strike the vibrating plate 94 that rotates in the opposite direction, causing the vibrating plate 94 to vibrate. The vibration generated by the vibrating plate 94 is transmitted through the scraper 9 to the scraper blade that contacts the outer wall of the horizontal section 211. The vibrating scraper blade is more effective in removing wet dust and corrosion residue on the outer wall of the horizontal section 211.

[0071] In some embodiments, the scraper 9 has multiple disturbance holes 96 circumferentially extending along the horizontal section 211. These disturbance holes 96 on the same scraper 9 are spaced apart axially along the horizontal section 211. The actual number of disturbance holes 96 can be increased or decreased according to the actual length of the scraper 9. Since the scraper 9 is in close contact with the outer wall of the horizontal section 211, when the scraper 9 rotates, it can disturb the exhaust gas flowing through the outer wall of the horizontal section 211. Some of the exhaust gas passes through the disturbance holes 96, further disrupting the laminar flow state of the exhaust gas that may occur at the outer wall of the horizontal section 211, thereby improving the efficiency of heat exchange between the exhaust gas and the heat exchange tube 21.

[0072] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0073] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0074] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A dust removal and cooling device for aluminum fluoride production, characterized in that: It includes, in sequence, a cyclone dust collector, a waste heat recovery unit, and a bag filter dust collector connected by pipes; The waste heat recovery unit is equipped with heat exchange tubes, which are arranged in a serpentine pattern in the vertical direction. The heat exchange tubes include multiple horizontally placed sections. Tail pipes are coaxially sleeved on the outside of each horizontal section of the heat exchange tube to form a closed annular heat exchange cavity outside the heat exchange pipe. The multiple tail pipes are connected by pipes. A first fixed seat is coaxially sleeved on the outer side of the horizontal section. A flow-guiding component is correspondingly arranged outside the first fixed seat. A sensor that can automatically expand and contract according to temperature is arranged inside the first fixed seat. When the sensor contracts, it can drive the flow-guiding component to close the annular heat exchange cavity corresponding to the first fixed seat. A turbulence channel is opened at one end of the first fixed seat. The turbulence channel connects the outer wall of the first fixed seat and the annular heat exchange cavity corresponding to the tail end. A turbulence fan blade is rotatably connected to one side of the first fixed seat at the tail end. A starting slider that can open and close the turbulence channel is slidably connected inside the first fixed seat. One end of the sensor is connected to the starting slider so that it can open the turbulence channel by contracting itself and driving the starting slider to slide. At the same time, the flow-guiding component closes the annular heat exchange cavity so that the tail flow passes through the turbulence channel and drives the turbulence fan blade to rotate. A second fixed seat is coaxially surrounding the first fixed seat, with a distance between the second fixed seat and the first fixed seat. The drainage component is correspondingly and movably disposed between the first fixed seat and the second fixed seat. The outer wall of the second fixed seat is in contact with the inner wall of the tailpipe. The second fixed seat includes a flow-incoming ring and a flow-out ring. The flow-incoming surface of the inner ring of the flow-incoming ring is a smoothly transitioned curved surface. The inner diameter of the flow-incoming ring is equal to the maximum inner diameter of the flow-out ring. Along the axial direction of the horizontal section and from the flow-incoming ring to the flow-out ring, the inner diameter of the flow-out ring gradually decreases. The diversion assembly includes a diversion plate, and multiple diversion plates are arranged circumferentially around the inner wall of the second fixed seat. One end of the diversion plate is rotatably connected to the maximum inner diameter of the wake ring, and the rotation axis is perpendicular to the axis of the horizontal section. The other end of the diversion plate is a free end. The end of the diversion plate rotatably connected to the wake ring is provided with a first return member to maintain the initial state of the diversion plate tightly attached to the inner wall of the wake ring. The end of the diversion plate away from the incoming flow ring is connected to the starting slider through a connecting rod. The diversion plate is an arc-shaped plate. When the free ends of all the diversion plates are in contact with the outer wall of the first fixed seat, the side walls of every two adjacent diversion plates are in contact to close the annular heat exchange cavity between the first fixed seat and the second fixed seat. At this time, the distance between the opening of the turbulence channel on the outer wall of the first fixed seat and the flow-facing end of the first fixed seat is less than the distance between the free end of the diversion plate and the flow-facing end of the first fixed seat.

2. The dust removal and cooling device for aluminum fluoride production according to claim 1, characterized in that: Multiple sensing channels are spaced apart along the circumference of the horizontal segment on the inner wall of the first fixed base. Each sensing channel is opened through the horizontal segment axis. The sensing elements are distributed in each sensing channel along the horizontal segment axis. One end of the sensing element is connected to the first fixed base, and the other end is connected to the end of the starting slider away from the turbulence fan blade. The turbulence channel and the sensing channel correspond one-to-one.

3. The dust removal and cooling device for aluminum fluoride production according to claim 2, characterized in that: A flow-guiding ring is provided at the tail end of the first fixed base. The outer wall of the flow-guiding ring is flush with the outer wall of the first fixed base. Along the axial direction of the horizontal section and away from the flow-facing end of the first fixed base, the distance between the flow-guiding ring and the outer wall of the horizontal section gradually decreases. The turbulence fan blade is located inside the cavity enclosed by the flow-guiding ring. A mounting seat is fitted on the horizontal section corresponding to the position of the turbulence fan blade. The turbulence fan blade is rotatably connected to the outer wall of the mounting seat. Along the radial direction of the horizontal section, the outer diameter of the mounting seat is larger than the inner diameter of the horizontal section corresponding to the sensing channel. The opening of the turbulence channel at the tail end of the first fixed base faces the turbulence fan blade.

4. The dust removal and cooling device for aluminum fluoride production according to claim 3, characterized in that: A scraper is provided on the side of the mounting base away from the tail end of the first fixed base. The scraper is close to the outer wall of the horizontal section and extends along the axial direction of the horizontal section. One end of the scraper is connected to the turbulence fan blade, and the other end of the scraper is provided with a limiting ring. The limiting ring is sleeved on the outside of the horizontal section. One end of the scraper is inserted into the limiting ring and slidably connected with the limiting ring so that the scraper can scrape the outer wall of the horizontal section when it rotates with the turbulence fan blade.

5. The dust removal and cooling device for aluminum fluoride production according to claim 4, characterized in that: A sealing ring is provided between the scraper and the mounting base. A striking block is provided inside the sealing ring. One end of the striking block near the scraper is a free end, and the other end is rotatably connected to the inner wall of the sealing ring. The axis of rotation is parallel to the axis of the horizontal section. One end of the scraper is inserted into the sealing ring and is connected to the turbulence fan blade through a coupling ring. A vibrating plate is provided on the coupling ring. When the vibrating plate rotates with the turbulence fan blade, the striking block can strike the vibrating plate to make the vibrating plate vibrate.

6. The dust removal and cooling device for aluminum fluoride production according to claim 4, characterized in that: The scraper is provided with multiple flow-through holes that penetrate circumferentially along the horizontal section, and the multiple flow-through holes are distributed at intervals along the axial direction of the horizontal section.

7. The dust removal and cooling device for aluminum fluoride production according to claim 1, characterized in that: The wake ring is provided with a swinging spoiler on the side wall away from the oncoming ring. One end of the swinging spoiler is rotatably connected to the position where the inner diameter of the wake ring is the smallest, and the other end is a free end.

8. The dust removal and cooling device for aluminum fluoride production according to claim 1, characterized in that: A support rod is provided between the first fixed seat and the second fixed seat, and the support rod is used to connect the first fixed seat and the second fixed seat into a whole.

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