A tail gas collection device for aluminum trichloride processing

Abstract

This invention discloses a tail gas collection device for aluminum trichloride processing, belonging to the technical field of separation equipment. The device includes a compensation component located downstream of the inlet pipe. The compensation component comprises a gas supply element and a connecting element. The gas supply element is externally connected to a supplier to introduce inert gas, and the connecting element is externally wrapped with a heating wire. This invention, through the design of the compensation component, introduces dry inert gas into the tail gas, which, combined with heating by the connecting element, allows the inert gas jet to mix thoroughly with the tail gas, effectively diluting the water vapor concentration in the tail gas. Combined with external auxiliary heating, this maintains high-temperature delivery of the tail gas, inhibiting the hydrolysis of aluminum trichloride at its source and preventing premature sublimation and blockage at pipe connections, thus ensuring smooth airflow.

Description

Technical Field

[0001] This invention belongs to the field of separation equipment technology, specifically relating to a tail gas collection device for aluminum trichloride processing. Background Technology

[0002] Aluminum trichloride, as an important inorganic chemical raw material, is widely used in catalysts, dyes, pharmaceuticals and electronic materials. In industrial production, it is usually produced by reacting metallic aluminum or alumina with chlorine at high temperature. This process generates a large amount of high-temperature tail gas containing aluminum trichloride vapor. The tail gas needs to be treated to meet emission standards before it can be discharged. Therefore, a tail gas treatment system is required for harmless treatment.

[0003] The existing Chinese invention patent with publication number CN115254424A describes an exhaust gas treatment system that uses a combination of condensation and bag filter dust removal. However, the residual moisture in the exhaust gas is difficult to remove completely, and even trace amounts of water vapor may cause aluminum trichloride hydrolysis, forming viscous deposits in low-temperature regions, which can cause blockages in pipes and separators. At the same time, if the unloading process is exposed to air, it is very easy to absorb moisture and deliquesce, making it difficult to achieve high-purity recovery.

[0004] In view of this, this solution provides a tail gas collection device for aluminum trichloride processing to solve the problems of safety, recovery rate and continuous operation in aluminum trichloride tail gas treatment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a tail gas collection device for aluminum trichloride processing.

[0006] The technical solution adopted to solve the above technical problems is:

[0007] A tail gas collection device for aluminum trichloride processing includes:

[0008] A compensation component is located downstream of the inlet pipe. The compensation component includes a gas supply element and a connecting element. The gas supply element is connected to an external supply device to introduce inert gas, and the connecting element is wrapped with a heating wire.

[0009] A separator includes a jacketed shell, the sidewall of which is provided with a heat exchange jacket filled with heat exchange medium, and an outlet pipe is provided at the middle of the top of the jacketed shell. The connecting member is connected to the jacketed shell through a bevel, and the outlet pipe is provided with a cavity filled with heat exchange medium at the bevel corresponding to the bevel.

[0010] The collector includes an upper shell, a middle shell, and a lower shell. The upper shell is connected to the top of the outlet pipe via a relay pipe. The middle shell has a built-in negative electrode plate. The negative electrode plate is provided with a discharge needle on one side inside the middle shell. The lower shell has a built-in collecting plate. An external pipe connected to the pickling tower is installed on the vertical side wall below the collecting plate of the lower shell.

[0011] In this process, inert gas is introduced into the exhaust gas through the inlet pipe at the compensation component location to dilute the water vapor concentration in the exhaust gas and inhibit the hydrolysis of aluminum trichloride solid. The temperature is controlled to be no lower than 200 degrees Celsius to prevent aluminum trichloride from sublimating at the connecting part and causing blockage. The exhaust gas enters the separator and rapidly exchanges heat with the heat exchange medium in the heat exchange jacket and cavity, causing aluminum trichloride to sublimate. Large aluminum trichloride solid particles are decelerated by friction on the inner wall of the separator and collected from the bottom. The remaining exhaust gas enters the collector through the outlet pipe, where small aluminum trichloride solid particles entrained in the exhaust gas are collected by electrostatic adsorption. Then, reverse electricity is applied to neutralize the charge, causing the powder to fall off for collection. Finally, the exhaust gas enters the acid washing treatment tower through the external pipe for neutralization of chlorine and hydrogen chloride to meet emission standards.

[0012] Furthermore, the air supply component includes a main pipe and a sleeve coaxially sleeved together, and the main pipe and the sleeve form an air passage cavity connected to the supply device. The main pipe has a built-in reducing inner diameter, and the main pipe has an oblique hole downstream of the reducing inner diameter.

[0013] The above technical solution discloses a specific configuration of an air supply component. The air passage receives inert gas continuously entering through a pipe. Due to the narrowing and increasing speed of the inner diameter of the main pipe, the air passage is heated by the high-velocity exhaust gas, causing the inert gas flowing through the air passage to reach a temperature close to that of the exhaust gas. The oblique hole achieves narrowing and increasing speed, while the downstream inner diameter of the narrowing and increasing inner diameter increases again, the air pressure in the main pipe decreases, and the inert gas is injected at high speed into the downstream of the narrowing and increasing inner diameter, so that the inert gas and the exhaust gas are fully mixed, ensuring that the inert gas is quickly dispersed into the exhaust gas.

[0014] Furthermore, the top of the sandwich shell is designed with an inner diameter contraction section, and the connecting piece is horizontally connected to the inner diameter contraction section. The air passage direction of the connecting piece is parallel to the tangential direction of the inner diameter of the inner diameter contraction section.

[0015] Through the above technical solution, in order to ensure the rapid sublimation of aluminum trichloride in the exhaust gas, the exhaust gas enters the jacket shell from the connecting part. The inner diameter contraction section prevents the exhaust gas velocity from rapidly decreasing due to the instantaneous expansion of space. Under the guidance of the inner wall of the jacket shell, the exhaust gas is reversed to form a rapid spiral airflow, which fully contacts the heat exchange medium in the heat exchange jacket and cavity. The heat exchange medium keeps the exhaust gas in the ideal sublimation temperature range, and the aluminum trichloride gas rapidly sublimates to form large, dry crystals that are easy to collect.

[0016] Furthermore, it also includes an output component, which is provided with an air supply ring located at the bottom outlet of the interlayer shell. The air supply ring has a nozzle at the bottom outlet of the interlayer shell. An external supply device is connected to the air supply ring to introduce inert gas. A main shell is provided at the bottom of the air supply ring. A flap valve is provided at the bottom of the main shell. A secondary shell is provided at the bottom of the flap valve. A quick-connect socket is provided at the bottom of the secondary shell.

[0017] The above technical solution achieves the collection of aluminum trichloride crystals by employing a dual-zone output component. During aluminum trichloride sublimation, the airflow velocity of the gas supply ring is slightly higher than the dust settling velocity, ensuring the solid falls into the main shell without disturbing the collection. If export is required, the top of the collection tank is inserted into the quick-connect socket to complete the connection. Then, the flap valve is opened, allowing the inert gas to quickly carry the solid into the secondary shell. The flap valve is then immediately closed. Through the dual-zone design, a dynamic gas barrier is established at the bottom outlet of the interlayer shell, preventing humid air from being drawn back into the interlayer shell from the bottom discharge port. This also increases the solid falling speed and shortens the opening time of the flap valve, effectively reducing the risk of outside air entering the interlayer shell.

[0018] Furthermore, the inner wall of the sandwich shell is coated, the inner wall of the bottom opening of the sandwich shell is provided with an annular array of notches, and the nozzle outlet direction is tilted upwards at ten to fifteen degrees.

[0019] Through the above technical solution, in order to ensure that aluminum trichloride solid enters the main shell smoothly, the coating can neutralize the static electricity generated by the friction of aluminum trichloride solid, prevent adsorption and agglomeration, and design a notch to destroy the integrity of the bottom opening of the sandwich shell. In addition, the upward blowing of inert gas can effectively prevent the bridging and blockage of aluminum trichloride solid at the bottom opening of the sandwich shell, and ensure that the aluminum trichloride solid falls quickly.

[0020] Furthermore, the main shell is provided with a liquid cavity and a material cavity. The liquid cavity is arranged around the outside of the material cavity. The liquid cavity is filled with heat exchange medium. The liquid cavity, heat exchange jacket and cavity are respectively connected to the circulation pipe group.

[0021] Through the above technical solution, during the stage of collecting aluminum trichloride solid and temporarily storing it in the main shell, the heat transfer oil in the liquid chamber is used to evenly heat the heater wall, so that the aluminum trichloride solid is at a temperature much higher than the dew point, which inhibits the adsorption of water molecules and keeps the crystals in a loose state. During the process, inert gas is continuously input, so that the main shell is at a pressure slightly higher than atmospheric pressure. Excess inert gas will rise and be discharged through the gas outlet pipe. At the moment the flap valve opens, the pressure difference carries the loose crystals, which can quickly complete the output and ensure that the opening time of the flap valve is short.

[0022] Furthermore, the upper shell has a built-in inclined plate, which is inclined at a 45-degree angle. An air passage is formed downstream of the upper shell through the inclined plate. A heat exchanger is provided on the outside of the upper shell, middle shell, and lower shell.

[0023] Through the above technical solution, in order to improve the charge adhesion efficiency of small-particle aluminum trichloride solids, before the exhaust gas contacts the discharge needle, the inclined plate guides the spiral airflow to form turbulence at the middle shell position, ensuring that the particles are fully dispersed, prolonging the residence time, and increasing the probability of collision with corona ions, thereby significantly improving the charge uniformity of small-particle aluminum trichloride solids and ensuring subsequent dust collection efficiency. In addition, throughout the process, the temperature replenisher ensures that the temperature is stable above the room temperature dew point and below the sublimation point of aluminum trichloride, keeping it solid but loose, inhibiting the adsorption of water molecules on the surface of aluminum trichloride, so that there are no cold spots in the entire system and preventing any localized high-risk areas for deliquescence from forming.

[0024] Furthermore, the discharge needle has four ridges, and the discharge needle has equidistant openings at the ridges. The ridges form sharp points at the openings, and the bottom of the openings forms rounded bottoms.

[0025] The above technical solution discloses an optimized structure for a discharge needle. Openings are equidistantly arranged on four edges to form a multi-tip array, constituting a distributed corona source. This not only reduces the corona initiation voltage but also makes the corona current more uniform, effectively avoiding local overheating and hot spot ablation. It is suitable for aluminum trichloride dust with high resistivity and fine particle size. At the same time, the bottom of the opening adopts a rounded bottom design to smoothly transition and disperse electric field stress, suppress charge accumulation and flashover, and prevent aluminum trichloride dust from accumulating at sharp corners to form conductive bridges. The overall structure works in synergy with the spiral airflow to achieve uniform electric field coverage without dead angles in the circumference, greatly improving the charging efficiency of fine particles. Moreover, the rounded structure facilitates nitrogen purging and cleaning, effectively resisting the operational risks caused by the deliquescence of aluminum trichloride dust.

[0026] Furthermore, the top of the collecting plate is provided with a purging assembly, the bottom of the purging assembly is provided with a convergent head that cooperates with the vertical sidewall of the collecting plate, the purging assembly is connected to an external supply to introduce inert gas, and a liner is provided between the collecting plate and the lower housing.

[0027] The above technical solution applies a brief negative high voltage to the collecting plate by reverse powering, repelling negatively charged aluminum trichloride dust to achieve neutralization and shedding. Each potential switch causes violent fluctuations in the corona current, resulting in a sharp drop in ion concentration in a short period of time, affecting the dust removal efficiency of small particles. By using a purging assembly with a convergent head having a slit, high-speed inert gas is used to blow away the aluminum trichloride dust, resulting in good cleaning effect and no charge fluctuations. It should be noted that during purging, the external pipe needs to be closed to allow the powder to fall fully to the bottom and be collected. In addition, the liner should prevent the lower housing from being electrically connected to the collecting plate to prevent the lower housing from carrying the same charge as the collecting plate, causing the aluminum trichloride dust to be adsorbed on the inner wall of the lower housing.

[0028] Furthermore, the bottom outlet of the lower housing is provided with a temporary storage component, which includes a second flap valve, a second flap valve with a conical hopper at its bottom, and a second quick-connect socket at the bottom of the conical hopper.

[0029] To ensure that aluminum trichloride powder can be smoothly discharged during purging, the above technical solution involves opening the second flap valve during purging, closing the external pipe using the valve on the external pipe, and connecting a negative pressure suction tube at the quick-connect port 2. The negative pressure is then used to quickly suck out the aluminum trichloride powder from the cone and lower shell, ensuring smooth collection.

[0030] The beneficial effects of this invention are as follows:

[0031] (1) The present invention introduces dry inert gas into the exhaust gas through the design of the compensation component and heats it with the connecting part. The inert gas jet mixes fully with the exhaust gas, effectively diluting the water vapor concentration in the exhaust gas. Combined with the external auxiliary heating design, the high temperature of the exhaust gas is maintained, inhibiting the hydrolysis of aluminum trichloride from the source and preventing it from prematurely condensing and blocking at the pipe connection, thus ensuring smooth airflow.

[0032] (2) This invention optimizes the separator by setting a dual cooling structure of heat exchange jacket and outlet pipe cavity in the separator, and combined with the design of oblique cut tangential air inlet and top contraction section, so as to promote the formation of high-speed spiral flow field of tail gas, realize the rapid and uniform sublimation of aluminum trichloride gas in tail gas, and obtain coarse dry crystals. The cyclone solid-gas separation structure significantly improves the sedimentation and collection efficiency of large aluminum trichloride particles. The output component adopts dual-zone sealing, dynamic gas seal and quick-connect interface design to effectively prevent solid bridge, electrostatic adsorption and external moisture intrusion, and realize the non-destructive transfer of high-purity aluminum trichloride.

[0033] (3) The present invention, through the design of the collector, targets the fine aluminum trichloride particles in the exhaust gas that are not easily separated by the cyclone separation structure. The collector integrates inclined plate guide and multi-point discharge needle. Through the optimization of airflow organization and the innovation of corona structure, the charging efficiency and collection rate of fine aluminum trichloride particles are greatly improved. Inert gas purging is used to avoid electric field disturbance and ensure long-term stable operation of the system. The whole process is kept warm to effectively prevent the wet decomposition of aluminum trichloride caused by low temperature, thus realizing the efficient recovery of fine aluminum trichloride particles. Attached Figure Description

[0034] Figure 1 This is a first-view structural diagram of the present invention;

[0035] Figure 2 This is a second-view structural diagram of the present invention;

[0036] Figure 3 This is a schematic diagram showing the positions of the inlet pipe, compensation component, separator, and output component of the present invention;

[0037] Figure 4 This is a schematic diagram of the structure between the inlet pipe, the compensation component, and the separator of the present invention;

[0038] Figure 5 This is an internal schematic diagram of the compensation component and the separator of the present invention;

[0039] Figure 6 This is a schematic diagram showing the position between the separator and the output component of the present invention;

[0040] Figure 7 This is a schematic diagram of the structure between the collector and the temporary storage component of the present invention;

[0041] Figure 8 This is a schematic diagram of the structure between the commutation component, the negative electrode plate, and the discharge needle in the collector of the present invention.

[0042] Figure 9 This is a schematic diagram of the structure of the discharge needle of the present invention;

[0043] Figure 10 This is a schematic diagram showing the position between the agglomeration plate and the purging assembly of the present invention.

[0044] Reference numerals: 1. Inlet pipe; 2. Compensation assembly; 21. Air supply component; 211. Main pipe; 212. Sleeve; 213. Air passage chamber; 214. Angled hole; 215. Reducing inner diameter; 22. Connecting component; 221. Heating wire; 222. Angled cut; 3. Separator; 31. Jacketed shell; 311. Heat exchange jacket; 312. Coating; 313. Notch; 32. Outlet pipe; 321. Cavity; 4. Output assembly; 41. Air supply ring; 411. Nozzle; 42. Main shell; 421. Liquid chamber; 422. Material chamber; 43. Flip valve one; 44. Secondary shell; 45. Quick-connect socket one; 5. Relay tube; 6. Collector; 61. Upper shell; 611. Inclined plate; 612. Gas passage; 62. Middle shell; 63. Negative electrode plate; 631. Discharge needle; 632. Ridge; 633. Opening; 634. Tip; 635. Rounded bottom; 64. Lower shell; 65. Accumulating plate; 651. Liner; 66. Purge assembly; 661. Converging head; 67. External pipe; 7. Temporary storage assembly; 71. Flip valve two; 72. Conical hopper; 73. Quick-connect socket two; 8. Supply unit; 9. Circulation tube assembly. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] like Figure 1 - Figure 10 As shown in the figure, this embodiment provides a tail gas collection device for aluminum trichloride processing. The tail gas collection device for aluminum trichloride processing mainly includes a compensation component 2, a separator 3, and a collector 6. The components are connected in sequence through pipelines. The specific structure and positional relationship are as follows:

[0047] The compensation component 2 is located downstream of the inlet pipe 1 and includes a gas supply component 21 and a connecting component 22. The gas supply component 21 is connected to the external supply device 8 and is used to introduce inert gas. Its outlet is connected to the interior of the connecting component 22. The outer periphery of the connecting component 22 is covered with a heating wire 221, and its end is connected to the separator 3 through a beveled cut 222.

[0048] The separator 3 includes a jacket shell 31, which is a hollow conical cylinder with a closed heat exchange jacket 311 inside its side wall for containing the heat exchange medium. An outlet pipe 32 is provided at the middle of the top of the jacket shell 31. A closed cavity 321 is provided at the upper end of the outlet pipe 32 corresponding to the oblique cut 222. This cavity 321 is also used to fill the heat exchange medium and is set independently from the heat exchange jacket 311. The lower end of the outlet pipe 32 extends to one-third of the lower section of the jacket shell 31 so that the exhaust gas can be led out.

[0049] Collector 6 is located downstream of separator 3 and is composed of upper shell 61, middle shell 62 and lower shell 64 connected from top to bottom. Upper shell 61 is sealed to the top of outlet pipe 32 through relay pipe 5. A negative electrode plate 63 is fixedly installed on one side inside the middle shell 62, and a discharge needle 631 is provided on the negative electrode plate 63. A collecting plate 65 is arranged opposite to the negative electrode plate 63 inside the lower shell 64. An interface is opened on the vertical side wall below it, and an external pipe 67 is installed at the interface for connecting to the acid washing treatment tower.

[0050] The working principle of this embodiment is as follows:

[0051] High-temperature exhaust gas containing aluminum trichloride vapor first enters the system through inlet pipe 1. Downstream at compensation component 2, dry, high-purity nitrogen gas is continuously injected into the exhaust gas via external supplier 8 and gas replenishment component 21. This effectively dilutes the volume concentration of water vapor in the exhaust gas, significantly reduces the partial pressure of water vapor, and inhibits the hydrolysis reaction of aluminum trichloride in subsequent processes. Simultaneously, heating wire 221 covering the connecting component 22 actively heats the mixed gas and maintains the temperature at no less than 200°C, ensuring that aluminum trichloride is always stably transported in gaseous form, preventing its hydrolysis in subsequent processes. Premature sublimation at the connection point causes blockage. Subsequently, the high-temperature exhaust gas enters the jacket shell 31 of the separator 3 tangentially through the oblique cut 222, where it undergoes efficient and rapid heat exchange with the heat exchange jacket 311 filled with heat transfer oil and the cavity 321 in the upper section of the outlet pipe 32. This causes the aluminum trichloride vapor to cool rapidly to below 178°C, undergoing a phase change and sublimating into solid particles. The larger aluminum trichloride particles lose kinetic energy after impacting the inner wall of the jacket shell 31 due to inertial collisions and gravitational settling, and slide down the wall to the bottom for initial collection. The remaining exhaust gas carrying fine particles (typically less than 5 μm) is discharged from the top outlet pipe 32. This exhaust gas enters the upper shell 61 of the collector 6 through the relay pipe 5 and flows downward through the middle shell 62 region. The middle shell 62 is equipped with a negative electrode plate 63 and a discharge needle 631 that works with it. Under the action of a high-voltage DC electric field, a stable corona discharge is generated, which fully charges the fine aluminum trichloride particles. Driven by the electric field force, the particles migrate towards the positively charged collecting plate 65 and are firmly adsorbed, achieving efficient collection. When the dust accumulation on the surface of the collecting plate 65 reaches the set value... When the thickness is constant, the system briefly switches to reverse power mode. By neutralizing the charge, the electrostatic adsorption force between the particles and the electrode plate is weakened, causing the powder to fall off in sheets and fall into the bottom of the lower shell 64 for secondary collection. Finally, the clean exhaust gas with solid particles removed is introduced into the acid washing treatment tower from the vertical side wall below the agglomeration plate 65 through the external pipe 67. The residual chlorine and hydrogen chloride and other acidic gases are neutralized by spraying with NaOH solution, ensuring that the emission indicators meet the environmental protection standards. This achieves safe, high recovery rate, and closed-loop treatment of aluminum trichloride exhaust gas.

[0052] In a further embodiment, the gas replenishment component 21 can be a three-way pipe. In addition to connecting the inlet pipe 1 to the air inlet of the separator 3, it can also be connected to the supply device 8 through a pipeline to replenish inert gas in the inlet pipe 1 and dilute the exhaust gas entering the separator 3.

[0053] In a further embodiment, a specific configuration of the air supply component 21 is disclosed, referring to... Figure 4 The air supply component 21 includes a main pipe 211 and a sleeve 212 coaxially sleeved together. The main pipe 211 and the sleeve 212 form an air passage chamber 213 connected to the supply device 8. The main pipe 211 has a built-in reducing inner diameter 215. The main pipe 211 has an oblique hole 214 downstream of the reducing inner diameter 215. The air passage chamber 213 receives inert gas continuously entering through the pipe. Due to the reduction in diameter and increase in speed at the position of the reducing inner diameter 215 of the main pipe 211, the air passage chamber 213 is heated by the high-velocity exhaust gas, causing the inert gas flowing through the air passage chamber 213 to reach a temperature close to that of the exhaust gas. The oblique hole 214 achieves the reduction in diameter and increase in speed, while the downstream inner diameter of the reducing inner diameter 215 increases again. The air pressure inside the main pipe 211 decreases, and the inert gas is injected at high speed into the downstream of the reducing inner diameter 215, so that the inert gas and the exhaust gas are fully mixed, ensuring that the inert gas is quickly dispersed into the exhaust gas.

[0054] In a further embodiment, to ensure rapid sublimation of aluminum trichloride in the exhaust gas, refer to Figure 4 and Figure 5 The top of the sandwich shell 31 is designed with an inner diameter contraction section. The connecting piece 22 is horizontally connected to the inner diameter contraction section. The air passage direction of the connecting piece 22 is parallel to the tangent direction of the inner diameter of the inner diameter contraction section. The exhaust gas enters the sandwich shell 31 from the connecting piece 22. The inner diameter contraction section prevents the exhaust gas velocity from rapidly decreasing due to the instantaneous expansion of the space. Under the guidance of the inner wall of the sandwich shell 31, the exhaust gas is reversed to form a rapid spiral airflow, which fully contacts the heat exchange medium in the heat exchange jacket 311 and the cavity 321. The heat exchange medium is 140°C heat transfer oil, which maintains the wall temperature ≤160°C, so that the exhaust gas is in the ideal sublimation temperature range. The aluminum trichloride gas quickly sublimates to form large, dry crystals that are easy to collect.

[0055] In a further embodiment, to achieve the collection of aluminum trichloride crystals, refer to Figure 3 and Figure 6It also includes an output component 4, which has a gas supply ring 41 located at the bottom outlet of the sandwich shell 31. The gas supply ring 41 has a nozzle 411 at the bottom outlet of the sandwich shell 31. An external supplier 8 is connected to the gas supply ring 41 to introduce inert gas. A main shell 42 is located at the bottom of the gas supply ring 41, and a flap valve 43 is located at the bottom of the main shell 42. A secondary shell 44 is located at the bottom of the flap valve 43, and a quick-connect socket 45 is located at the bottom of the secondary shell 44. The output component 4, with its dual-zone design, has a gas flow velocity in the gas supply ring 41 slightly higher than that of the dust settling point during aluminum trichloride deposition. The collection process involves slowing down the solids to allow them to fall into the main shell 42 without disturbing the collection. If it is necessary to discharge the solids, the top of the collection tank is inserted into the quick-connect socket 45 to complete the connection. Then, the flap valve 43 is opened to allow the inert gas to carry the solids into the secondary shell 44 quickly. The flap valve 43 is then immediately closed. Through the dual-zone design, a dynamic gas barrier is established at the bottom outlet of the interlayer shell 31 to prevent humid air from being drawn back into the interlayer shell 31 from the bottom discharge port. This also increases the falling speed of the solids and shortens the opening time of the flap valve 43, effectively reducing the risk of outside air entering the interlayer shell 31.

[0056] In a further embodiment, to ensure that solid aluminum trichloride smoothly enters the main shell 42, refer to Figure 5 The inner wall of the sandwich shell 31 is provided with a conductive coating 312. The conductive coating 312 can not only effectively reduce the static electricity generated by friction when aluminum trichloride solid slides on the inner wall, but also conduct and neutralize this static electricity through the grounding of the sandwich shell 31, thereby avoiding the adsorption and agglomeration of particles. In addition, the inner wall of the bottom opening is provided with an annular array of notches 313. The annular array of notches 313 disrupts the continuity of the bottom opening of the sandwich shell 31, reducing the possibility of solid particles forming bridges or accumulating here. At the same time, the outlet direction of the nozzle 411 is tilted upward by 10° to 15°, which, together with the purging action of inert gas, further enhances this effect. The directional blowing of inert gas can not only provide additional propulsion to help solid particles overcome gravity and friction to fall quickly, but also break any possible bridge structure through the disturbance of airflow, ensuring that aluminum trichloride solid smoothly enters the main shell 42 from the bottom opening of the sandwich shell 31, and finally achieves efficient collection. This comprehensive design significantly improves the stability and reliability of the system and avoids operation interruption due to blockage.

[0057] In a further embodiment, during the stage where aluminum trichloride solid is collected and temporarily stored in the main shell 42, refer to Figure 6The main shell 42 is provided with a liquid chamber 421 and a material chamber 422. The liquid chamber 421 is arranged around the outside of the material chamber 422. The liquid chamber 421 is filled with heat exchange medium. The liquid chamber 421, the heat exchange jacket 311 and the cavity 321 are respectively connected to the circulation pipe group 9. The heat transfer oil in the liquid chamber 421 is used to evenly heat the heater wall, so that the aluminum trichloride solid is at a temperature much higher than the dew point, which inhibits the adsorption of water molecules and keeps the crystal loose. During the process, inert gas is continuously input, so that the main shell 42 is at a pressure slightly higher than atmospheric pressure. Excess inert gas will rise and be discharged through the gas outlet pipe 32. At the moment the flap valve 43 opens, the pressure difference carries the loose crystals, which can quickly complete the output, ensuring that the opening time of the flap valve 43 is short.

[0058] In a further embodiment, to improve the charge adhesion efficiency of small-particle aluminum trichloride solids, the internal channels of the upper shell 61 are optimized, referring to... Figure 8 The upper shell 61 has a built-in inclined plate 611, which is set at a 45-degree angle. Downstream of the upper shell 61, an air passage 612 is formed through the inclined plate 611. Before the exhaust gas contacts the discharge needle 631, the inclined plate 611 guides the airflow to form a spiral airflow, which forms turbulence at the position of the middle shell 62. This ensures that the particles are fully dispersed, prolongs the residence time, and increases the probability of collision with corona ions, thereby significantly improving the uniformity of charge of small aluminum trichloride solid particles and ensuring the subsequent dust collection efficiency. The upper shell 61, middle shell 62 and lower shell 64 are equipped with a temperature compensator. Throughout the process, the temperature compensator ensures that the temperature is stable at 80 to 100 degrees Celsius, which is higher than the room temperature dew point and lower than the sublimation point of aluminum trichloride. This keeps the aluminum trichloride solid but loose, inhibits the adsorption of water molecules on the surface of aluminum trichloride, and makes the whole system free of cold spots, preventing any local temperature from falling below 60 degrees Celsius and forming a high-risk area for deliquescence.

[0059] In a further embodiment, an optimized structure of the discharge needle 631 is disclosed, referring to... Figure 9The discharge needle 631 has four ridges 632, and equidistant openings 633 are provided at the ridges 632. The ridges 632 form sharp points 634 at the openings 633, and the bottom of the openings 633 forms an arc bottom 635. Specifically, the openings 633 are equidistantly arranged on the four 90-degree symmetrically distributed ridges 632, forming an array of multiple sharp points 634, which constitutes a distributed corona source. This not only reduces the corona initiation voltage by 15% to 25%, but also makes the corona current more uniform and effectively avoids local overheating. With hot spot ablation, it is suitable for aluminum trichloride dust with high resistivity and fine particle size. At the same time, the bottom of the opening 633 adopts the arc bottom design of R=1-3mm 635, which smoothly transitions to disperse electric field stress, suppress charge accumulation and flashover, and prevent aluminum trichloride dust from accumulating at sharp corners to form conductive bridges. The overall structure works in synergy with the spiral airflow to achieve uniform electric field coverage without dead angles in the circumference, which greatly improves the charging efficiency of fine particles. Moreover, the arc structure facilitates nitrogen purging and cleaning, effectively resisting the operational risks caused by the deliquescence of aluminum trichloride dust.

[0060] In a further embodiment, a brief negative high voltage is applied to the collecting plate 65 by reverse current, repelling negatively charged aluminum trichloride dust to complete neutralization and shedding. Each potential switch causes drastic fluctuations in the corona current, resulting in a sharp drop in ion concentration within a short period, affecting the dust removal efficiency of small particles. (Refer to...) Figure 10 The top of the collecting plate 65 is equipped with a blowing assembly 66, and the bottom of the blowing assembly 66 is equipped with a converging head 661 that cooperates with the vertical sidewall of the collecting plate 65. An external supply 8 is connected to the blowing assembly 66 to introduce inert gas. A liner 651 is provided between the collecting plate 65 and the lower housing 64. By using the blowing assembly 66 and the converging head 661 with a slit, high-speed inert gas is used to blow away aluminum trichloride dust, resulting in good cleaning effect and no charge fluctuation. It should be noted that during the blowing process, the external pipe 67 needs to be closed to allow the powder to fall fully to the bottom and be collected. In addition, the liner 651 prevents the lower housing 64 from being electrically connected to the collecting plate 65, preventing the lower housing 64 from carrying the same charge as the collecting plate 65, which would cause the aluminum trichloride dust to be adsorbed on the inner wall of the lower housing 64.

[0061] In a further embodiment, to ensure that aluminum trichloride powder can be smoothly discharged during purging, refer to Figure 7 The bottom outlet of the lower housing 64 is provided with a temporary storage component 7, which includes a flap valve 2 71. The bottom of the flap valve 2 71 is provided with a cone 72, and the bottom of the cone 72 is provided with a quick-connect plug 2 73. During the purging moment, the flap valve 2 71 is opened, and the valve on the outer pipe 67 (not shown in the figure) is used to close the outer pipe 67. The negative pressure suction tube is connected at the quick-connect plug 2 73, and the aluminum trichloride powder in the cone 72 and the lower housing 64 is quickly sucked out by the negative pressure to ensure the smooth collection.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A tail gas collection device for aluminum trichloride processing, characterized in that, include: Compensation component (2), the compensation component (2) is located downstream of the inlet pipe (1), the compensation component (2) includes a gas supply component (21) and a connecting component (22), the gas supply component (21) is connected to an external supply device (8) to introduce inert gas, and the connecting component (22) is wrapped with a heating wire (221). The separator (3) includes a sandwich shell (31), the side wall of which is provided with a heat exchange jacket (311) filled with heat exchange medium, and the top center of the sandwich shell (31) is provided with an air outlet pipe (32). The connecting piece (22) is connected to the sandwich shell (31) through a bevel (222). The air outlet pipe (32) is provided with a cavity (321) filled with heat exchange medium at the bevel (222). The collector (6) includes an upper shell (61), a middle shell (62) and a lower shell (64). The upper shell (61) is connected to the top of the outlet pipe (32) via a relay pipe (5). The middle shell (62) has a built-in negative electrode plate (63). The negative electrode plate (63) has a discharge needle (631) on one side inside the middle shell (62). The lower shell (64) has a built-in collecting plate (65). The lower shell (64) has an external pipe (67) connected to the pickling tower installed on the vertical side wall below the collecting plate (65). In this process, the tail gas in the inlet pipe (1) is mixed with inert gas at the compensation component (2) and the temperature is controlled to be no less than 200 degrees Celsius. The tail gas enters the separator (3) and rapidly exchanges heat with the heat exchange medium in the heat exchange jacket (311) and cavity (321) to cause aluminum trichloride to sublimate. The tail gas discharged from the outlet pipe (32) enters the collector (6) for electrostatic adsorption collection of aluminum trichloride. The tail gas enters the pickling treatment tower through the external pipe (67).

2. The tail gas collection device for aluminum trichloride processing according to claim 1, characterized in that, The air supply component (21) includes a main pipe (211) and a sleeve (212) coaxially sleeved together. The main pipe (211) and the sleeve (212) form an air passage (213) connected to the supply device (8). The main pipe (211) has a built-in scaling inner diameter (215). The main pipe (211) has an oblique hole (214) downstream of the scaling inner diameter (215).

3. The tail gas collection device for aluminum trichloride processing according to claim 2, characterized in that, The top of the sandwich shell (31) is designed with an inner diameter contraction section, and the connecting piece (22) is horizontally connected to the inner diameter contraction section. The air passage direction of the connecting piece (22) is parallel to the inner diameter tangent direction of the inner diameter contraction section.

4. The tail gas collection device for aluminum trichloride processing according to claim 1, characterized in that, It also includes an output component (4), which is provided with an air supply ring (41). The air supply ring (41) is located at the bottom outlet of the sandwich shell (31). The air supply ring (41) has a nozzle (411) at the bottom outlet of the sandwich shell (31). The air supply ring (41) is connected to an external supplier (8) to introduce inert gas. The bottom of the air supply ring (41) is provided with a main shell (42). The bottom of the main shell (42) is provided with a flap valve (43). The bottom of the flap valve (43) is provided with a secondary shell (44). The bottom of the secondary shell (44) is provided with a quick-connect socket (45).

5. The tail gas collection device for aluminum trichloride processing according to claim 4, characterized in that, The inner wall of the sandwich shell (31) is provided with a coating (312), and the inner wall of the bottom opening of the sandwich shell (31) is provided with an annular array of notches (313). The nozzle (411) is inclined upward at ten to fifteen degrees in the outlet direction.

6. The tail gas collection device for aluminum trichloride processing according to claim 5, characterized in that, The main shell (42) is provided with a liquid chamber (421) and a material chamber (422). The liquid chamber (421) is arranged around the outside of the material chamber (422). The liquid chamber (421) is filled with heat exchange medium. The liquid chamber (421), the heat exchange jacket (311) and the cavity (321) are respectively connected to the circulation pipe group (9).

7. The tail gas collection device for aluminum trichloride processing according to claim 4, characterized in that, The upper shell (61) has a built-in inclined plate (611) at a 45-degree angle. The upper shell (61) has an air passage (612) formed downstream of the inclined plate (611). The upper shell (61), middle shell (62) and lower shell (64) are provided with a heat exchanger.

8. The tail gas collection device for aluminum trichloride processing according to claim 7, characterized in that, The discharge needle (631) has four ridges (632), and the discharge needle (631) has equidistant openings (633) at the ridges (632). The ridges (632) form a tip (634) at the openings (633), and the bottom of the openings (633) forms a rounded bottom (635).

9. The tail gas collection device for aluminum trichloride processing according to claim 8, characterized in that, The top of the collecting plate (65) is provided with a purging assembly (66), and the bottom of the purging assembly (66) is provided with a convergence head (661) that cooperates with the vertical sidewall of the collecting plate (65). The purging assembly (66) is connected to an external supply (8) to introduce inert gas. A liner (651) is provided between the collecting plate (65) and the lower housing (64).

10. The tail gas collection device for aluminum trichloride processing according to claim 9, characterized in that, The lower housing (64) has a temporary storage component (7) at its bottom outlet. The temporary storage component (7) includes a second flap valve (71), the bottom of which is provided with a cone hopper (72), and the bottom of which is provided with a quick-connect socket (73).

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