A method and system for reducing chlorine content of dust

Abstract

The present application relates to the technical field of post-treatment of titanium sponge production, in particular to a dust removal method and system for reducing chlorine content, the system comprising a gas collecting hood, a lateral air inlet, a multi-stage flow guide baffle, a heat dissipation fin, a forced cooling unit, a temperature sensor, a control system, a dust collecting hopper and a dust discharge valve; the method realizes preliminary separation of coarse particles by forming a cyclone through tangential air inlet, and the three-stage collaborative cooling system composed of the multi-stage flow guide baffle, the heat dissipation fin and the forced cooling unit stably controls the temperature of chlorine at 60-70 DEG C, so as to promote the full condensation of gaseous chlorides, and then realize gas-solid separation through gravity settling, and the collected dust is directly returned to the electrolytic cell for recycling. The present application has high heat exchange efficiency, the dust recovery rate is not less than 90%, the dust content of purified chlorine is not higher than 10 mg / m3, the maintenance frequency of subsequent equipment is greatly reduced, and the present application has energy saving and environmental protection and high adaptability, and is suitable for various electrolytic chlorine production scenes.

Description

Technical Field

[0001] This invention relates to the field of post-processing technology in sponge titanium production, specifically to a dust removal method and system for reducing chlorine content. Background Technology

[0002] Chlorine, as an important chemical raw material, is widely used in chemical, pharmaceutical, and water treatment industries, with electrolytic chlorine production being its primary method. In the production of sponge titanium, a complete sponge titanium plant generates a large amount of magnesium chloride as a byproduct during the reduction-distillation process. This magnesium chloride is promptly sent to the electrolysis workshop, where it is electrolyzed in an electrolytic cell to produce metallic magnesium and chlorine. The chlorine produced by electrolysis is then sent to the chlorination process, thus achieving a closed-loop cycle of raw materials. Currently, multi-stage electrolytic cells are commonly used in the industrial market for electrolysis operations. After being drawn out through a gas collection hood, the chlorine is sent to the chlorination compressor chamber under negative pressure, where it undergoes dust and water removal treatment before being sent to the chlorination workshop.

[0003] During the electrolytic chlorine production process, the high-temperature chlorine gas generated in the electrolytic cell not only carries electrolyte dust such as magnesium chloride and calcium chloride, but also contains a small amount of gaseous chlorides. The presence of these impurities can seriously affect the subsequent use of chlorine gas and production safety. Currently, commonly used industrial chlorine dust removal technologies mainly include bag filters, cyclone filters, spray filters, and electrostatic precipitators. While baghouse dust collectors can capture fine dust particles, high-temperature chlorine gas easily causes filter bags to age and break, requiring frequent replacements and resulting in high maintenance costs. Furthermore, gaseous chlorine cannot be effectively removed and easily condenses and clogs the filter bag surface, affecting dust removal efficiency. Cyclone dust collectors are mainly for coarse dust particles, with poor removal effects on fine dust particles and gaseous chlorine, making it difficult to meet the stringent dust content requirements of subsequent chlorine compressor systems. Spray dust collectors can achieve synergistic cooling and dust removal, but they generate chlorine-containing wastewater, causing secondary pollution, high subsequent wastewater treatment costs, and easily leading to chlorine dissolution and loss, reducing chlorine recovery rates. Electrostatic precipitators require large investments, have complex structures, are sensitive to corrosive impurities in chlorine, and are prone to electrode corrosion, dust accumulation, and scaling problems, resulting in poor operational stability and making them unsuitable for small and medium-sized electrolytic chlorine production plants.

[0004] Existing technologies generally suffer from a core pain point: the high-temperature chlorine gas produced by electrolysis naturally cools down after leaving the electrolytic cell, causing the chlorides carried by the gas to condense into fine powder. This powder settles in the system as it passes through the gas collection hood and pipelines, accumulating over time and clogging pipelines, reducing transmission efficiency, causing increased equipment wear and corrosion, and affecting production continuity. Simultaneously, existing chlorine dust removal technologies suffer from poor synergy between cooling and dust removal; the high-temperature chlorine gas is not thoroughly cooled, failing to fully condense the gaseous chlorides into solid particles, resulting in poor overall dust removal efficiency. Unremoved dust and gaseous chlorides entering the subsequent chlorine compressor system further exacerbate equipment wear and pipeline blockage, increasing equipment maintenance frequency and production costs. Furthermore, the electrolyte dust collected in existing technologies is difficult to recycle, leading to resource waste, and some dust removal processes are energy-intensive and environmentally unfriendly, failing to align with current industrial development trends focused on energy conservation and environmental protection.

[0005] In view of the shortcomings of the existing technologies, there is an urgent need to develop a chlorine dust removal system and method that can achieve synergistic effects of cooling and dust removal, stable purification effect, reliable operation, energy saving and environmental protection, and can realize the recycling of electrolyte dust, so as to solve the technical pain points in the existing technologies and meet the high standards of chlorine purification required for large-scale industrial production. Summary of the Invention

[0006] The purpose of this invention is to provide a dust removal method and system for reducing chlorine content, in order to solve the problems mentioned in the background art, such as poor synergy between cooling and dust removal, poor purification effect, large equipment wear and tear, and difficulty in dust recovery in traditional electrolytic chlorine production dust removal technology in sponge titanium plants.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A dust removal system for reducing chlorine content includes:

[0009] A gas collection hood is installed above the chlorine electrolysis cell to collect the high-temperature, dust-laden chlorine gas generated by the electrolysis cell.

[0010] A side air inlet is provided on the bottom side wall of the gas collection hood to guide high-temperature dust-laden chlorine gas into the gas collection hood in a tangential manner and form a swirling flow, thereby achieving the initial inertial separation of coarse dust particles.

[0011] Multi-stage baffles are staggered in the internal cavity of the gas collection hood, dividing the airflow channel inside the gas collection hood into a meandering S-shaped path;

[0012] The heat dissipation structure consists of several heat dissipation fins disposed on the outer wall of the gas collection shroud to increase the natural convection heat dissipation area; the forced cooling unit acts on the gas collection shroud to provide auxiliary cooling.

[0013] An outlet pipe is installed at the top or upper part of the gas collection hood to discharge cooled and purified chlorine gas.

[0014] A dust collection hopper, located at the bottom of the gas collection hood, is used to collect settled solid dust particles.

[0015] An ash discharge valve is installed at the bottom of the ash collection hopper to discharge the collected dust; a temperature sensor is installed at the outlet pipe to monitor the real-time temperature of the outlet chlorine gas.

[0016] The control system is connected to the temperature sensor and the forced cooling unit for dynamically adjusting the cooling intensity;

[0017] The system enhances heat transfer through the synergistic effect of multi-stage flow-guiding baffles and heat dissipation fins, and its heat transfer efficiency satisfies the following formula:

[0018] ;

[0019] In the formula, The heat exchange efficiency between chlorine gas and the gas collection hood; The combined heat transfer coefficient of the gas collection hood wall and the multi-stage flow guide baffles is expressed in W / (m²). 2 ·℃); The total heat exchange area between the multi-stage flow guide baffles and the inner wall of the gas collection hood is expressed in m². 2 ; This is the mass flow rate of chlorine gas, in units of... ; This is the isobaric specific heat capacity of chlorine gas, expressed in J / (kg·℃).

[0020] Preferably, the multi-stage flow guide baffles are at least three stages, with adjacent flow guide baffles staggered and fixed on the opposite inner walls of the gas collection hood, and the flow guide baffles are at an angle of 15°-45° to the horizontal direction, in order to extend the airflow path and enhance the heat exchange efficiency.

[0021] Preferably, the flow guide baffle is made of a metal material with a thermal conductivity of not less than 100 W / (m·℃), the end of the flow guide baffle is thermally connected to the inner wall of the gas collecting hood, and the surface of the flow guide baffle is sandblasted to form a roughness. A rough surface with a thickness of 1.6-6.3 μm;

[0022] The collision and dust collection efficiency of the baffle plate satisfies the following formula:

[0023] ;

[0024] In the formula, To improve dust collision and collection efficiency; The dust collision coefficient on the surface of the baffle plate is expressed in meters (m). -1 ; The effective capture area of ​​the flow guide baffle is expressed in m². 2 ; The effective residence time of chlorine gas inside the gas collection hood, in units of .

[0025] Preferably, the forced cooling unit is a cooling jacket surrounding the outside of the air collection shroud, the cooling jacket having a cooling medium inlet and a cooling medium outlet; or the forced cooling unit is a fan assembly pointing towards the outer wall of the air collection shroud.

[0026] The control system (10) uses a PID algorithm to adjust the flow rate of the cooling medium or the fan speed. The adjustment formula is as follows:

[0027] ;

[0028] In the formula, The output of the cooling unit is adjusted. This is the proportionality coefficient; This is the temperature deviation value. , For preset temperature, This is the measured temperature; The integral time constant; is the differential time constant.

[0029] Preferably, the preset temperature The temperature range is 60℃ to 70℃, which is lower than the dew point temperatures of magnesium chloride and calcium chloride, ensuring sufficient condensation of gaseous chlorides. The temperature sensor has a monitoring accuracy of ±0.5℃, and the control system's adjustment response time does not exceed 2 seconds. The adjusted temperature deviation value is... The absolute value should not exceed 2℃ to avoid the chloride from re-vaporizing due to temperature fluctuations.

[0030] Preferably, the ash collection hopper has a conical structure with a cone angle of 30°-60° to facilitate the downward sliding and settling of dust; the ash discharge valve has a double-valve linkage structure to prevent chlorine gas leakage from the gas collection hood.

[0031] The dust recovery rate of the system satisfies the following formula:

[0032] ;

[0033] In the formula, Dust recovery rate; The mass of dust collected in the dust hopper is expressed in units of... ; The total mass of dust carried by the chlorine gas entering the gas collection hood, in units of... And the dust recovery rate No less than 90%.

[0034] Preferably, the gas collecting hood is made of chlorine-resistant titanium alloy or polytetrafluoroethylene composite material, with a wall thickness of 8-15mm, which can withstand the high-temperature corrosive environment above the electrolytic cell and has a service life of not less than 5 years.

[0035] On the other hand, the present invention also provides a dust removal method for reducing chlorine content using the above-described system, comprising the following steps:

[0036] S1: Chlorine gas collection. High-temperature chlorine gas with a temperature of 200℃-300℃, carrying electrolyte dust such as magnesium chloride and calcium chloride, escapes from the electrolytic cell. It enters the gas collection hood at a tangential angle of 15°-30° through the side air inlet at the bottom of the gas collection hood, forming a swirling flow field. The inertial force is used to achieve the initial separation of coarse dust particles with a particle size greater than 5μm.

[0037] S2: Three-stage synergistic cooling and dust removal, including:

[0038] S2a: Primary cooling and dust removal. Chlorine gas flows through an S-shaped meandering channel formed by multiple flow guide baffles. The flow velocity is reduced from the initial 3m / s-5m / s to 0.8m / s-1.2m / s. The airflow collides and conducts heat exchange with the flow guide baffles multiple times. The heat exchange time is not less than 5s. Some dust and gaseous chloride condense and adhere to the surface of the baffles, achieving preliminary cooling and dust removal.

[0039] S2b: Secondary cooling and dust removal. The heat carried by chlorine gas is conducted to the external heat dissipation fins through the wall of the gas collection hood. The heat transfer coefficient between the fins and the air through natural convection is 5W / (m²·℃)-10W / (m²·℃), and secondary cooling is achieved through natural convection.

[0040] S2c: Three-stage precise cooling, the forced cooling unit is activated to assist in cooling the gas collection hood, and the cooling intensity is adjusted in real time according to the outlet temperature;

[0041] S3: Temperature closed-loop control and condensation. The temperature sensor collects the chlorine temperature at the outlet pipe in real time. The control system dynamically adjusts the operating parameters of the forced cooling unit based on the temperature feedback signal to stably control the outlet chlorine temperature within the preset range, so that the chlorine temperature is lower than the dew point temperature of gaseous chlorides such as magnesium chloride and calcium chloride, which promotes the full condensation of gaseous chlorides into solid particles.

[0042] S4: Gas-solid separation and conveying. Solid particles formed by condensation and dust adhering to the surface of the guide baffle fall into the dust collection hopper after gravity settling or airflow scouring, with a settling time of not less than 8 seconds; the purified low-dust chlorine gas is discharged from the outlet pipe and enters the subsequent chlorine compressor system to achieve dust-free conveying.

[0043] S5: Dust recovery. The dust discharge valve is opened periodically to discharge the dust collected in the dust collection hopper directly into the electrolytic cell, so as to realize the recycling of electrolyte.

[0044] In step S3, the effective residence time of chlorine gas in the gas collecting hood satisfies the following formula:

[0045]

[0046] In the formula, The effective residence time of chlorine gas inside the gas collection hood, in units of ; The effective volume of the airflow channel inside the gas collection hood, in meters. 3 ; This is the volumetric flow rate of chlorine gas, in m³ / s. 3 / s; The coefficient of airflow channel contraction caused by the baffle plate ranges from 0.4 to 0.7.

[0047] Preferably, in step S3, the chlorine temperature at the outlet pipe is monitored in real time, and the operating parameters of the forced cooling unit are controlled accordingly. If the forced cooling unit is a cooling jacket, the cooling water flow rate is adjusted to 5 m³ / h-20 m³ / h; if it is a fan assembly, the fan speed is adjusted to 1000 r / min-3000 r / min. The forced cooling unit is equipped with a backup power supply with a battery life of no less than 2 hours to ensure continuous temperature control after a power outage. The outlet chlorine temperature is stably controlled between 60°C and 70°C, meeting the feed temperature requirements of the downstream chlorine compressor system. This reduces the frequency of cleaning sublimation from the chlorine main pipe from once every half month to once every three months, and the frequency of cleaning the downstream bag filter from once a week to once a month.

[0048] Preferably, in step S5, the ash discharge valve is opened once every 12 hours, and each opening lasts for 10-30 seconds. During the ash discharge process, the opening and closing sequence of the two valves is maintained. First, the lower valve is opened to discharge ash. After the ash discharge is completed, the lower valve is closed. Then, the upper valve is opened to allow the dust in the ash collection hopper to fall, thus preventing chlorine gas from escaping from the gas collection hood.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] (1) The dust removal method for reducing chlorine content in this invention is synergistic with the system cooling and dust removal, resulting in significant and stable purification effects. It solves the technical pain points of incomplete cooling, low dust collection efficiency, and difficulty in effectively removing gaseous chlorides in existing chlorine dust removal technologies. This invention forms a swirling flow field through the gas collection hood and side air inlet to achieve preliminary inertial separation of coarse dust particles. Combined with the S-shaped meandering channel constructed by multi-stage guide baffles, the residence time of chlorine is extended and the heat exchange and collision area is increased. With the natural convection heat exchange of the heat dissipation fins and the precise cooling of the forced cooling unit, a three-stage synergistic cooling system is formed with a heat exchange efficiency of not less than 85%. It can stably reduce high-temperature chlorine to a preset range of 60°C to 70°C, which is lower than the dew point temperature of magnesium chloride and calcium chloride, thus promoting the full condensation of gaseous chlorides into solid particles. Meanwhile, the rough surface of the baffle plate treated by sandblasting and the reasonable angle design, combined with the optimization of dust collision collection efficiency parameters, make the dust collision collection efficiency no less than 75%, ultimately achieving a dust content of no more than 10mg / m³ in the purified chlorine gas and a dust recovery rate of no less than 90%, which is significantly better than existing dust removal technologies and effectively avoids wear and blockage of the subsequent chlorine compressor system by dust and gaseous chlorides.

[0051] (2) The chlorine dust removal system of the present invention is stable and reliable in operation, highly safe, low in maintenance cost and long in service life, and suitable for the needs of industrial-scale production. The present invention has optimized the structure and material of each component. The gas collection hood is made of chlorine-resistant titanium alloy or polytetrafluoroethylene composite material with a wall thickness controlled at 8 to 15 mm. It can withstand the high temperature corrosion environment of 200℃ to 300℃ and has a service life of not less than 5 years. The ash discharge valve adopts a double valve linkage structure to effectively prevent chlorine leakage and ensure production safety. The control system adopts a PID closed-loop regulation algorithm, combined with the high-precision monitoring of the temperature sensor. The regulation response time is no more than 2 seconds, which can control the outlet chlorine temperature deviation within ±2℃, avoid the re-vaporization of chlorine caused by temperature fluctuations and ensure the stability of system operation. In addition, the present invention uses a dust recovery and recycling design to directly discharge the collected electrolyte dust into the electrolytic cell, reducing resource waste and significantly reducing the maintenance frequency of the back-end equipment. The frequency of cleaning sublimation of the chlorine main pipe is reduced from once every half month to more than 3 months, and the frequency of cleaning the back-end bag filter is reduced from once a week to more than once a month, which significantly reduces labor and material costs.

[0052] (3) The dust removal method and system for reducing chlorine content of the present invention are energy-saving, environmentally friendly, and highly adaptable. The present invention adopts a staged cooling mode of natural heat dissipation + forced cooling. The heat dissipation fins increase the natural convection heat transfer area. The forced cooling unit can be implemented in two forms: cooling jacket or fan group, according to actual needs, to adapt to different scales of chlorine production scenarios. Compared with the existing single cooling mode, energy consumption is reduced by more than 15%, which is in line with the industrial development trend of energy conservation and environmental protection. At the same time, the present invention uses a synergistic dust removal mechanism of cyclone separation, collision capture, and condensation sedimentation, which eliminates the need to add additional dust removal agents, avoids secondary pollution caused by the use of agents, and has a high dust recovery rate, which reduces the waste of electrolyte resources and reduces the impact of dust emissions on the environment. Attached Figure Description

[0053] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are explained in detail together with the embodiments of the invention, but do not constitute a limitation thereof.

[0054] Figure 1 This is a schematic diagram illustrating the structural principle of the chlorine dust removal system of the present invention;

[0055] Figure 2 This is a schematic diagram illustrating the installation principle of the flow guide baffle of the present invention;

[0056] Figure 3 This is a flowchart illustrating the core architecture of the dust removal method for reducing chlorine content according to the present invention.

[0057] The meanings of the labels in the diagram are as follows: 1-Gas collection hood; 2-Side air inlet; 3-Outlet pipe; 4-Flow guide baffle; 5-Heat dissipation fins; 6-Forced cooling unit; 7-Cooling medium inlet; 8-Cooling medium outlet; 9-Temperature sensor; 10-Control system; 11-Ash hopper; 12-Ash discharge valve; 13-Electrolytic cell. Detailed Implementation

[0058] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] like Figure 1 and Figure 2 As shown, the dust removal system for reducing chlorine content of the present invention mainly consists of a gas collection hood 1, a side air inlet 2, an outlet pipe 3, a multi-stage flow guide baffle 4, heat dissipation fins 5, a forced cooling unit 6, a temperature sensor 9, a control system 10, a dust collection hopper 11, a dust discharge valve 12, and an electrolytic cell 13. The specific structure, connection relationship, and working principle of each component are as follows:

[0060] A gas collecting hood 1 is installed above the electrolytic cell 13 to comprehensively collect the high-temperature, dust-laden chlorine gas generated during the operation of the electrolytic cell 13. The gas collecting hood 1 is made of chlorine-resistant titanium alloy or polytetrafluoroethylene composite material, with a wall thickness of 8 to 15 mm. It can withstand the high-temperature corrosive environment of 200°C to 300°C above the electrolytic cell 13, ensuring a service life of no less than 5 years. The inner wall of the gas collecting hood 1 is thermally connected to the multi-stage flow guide baffles 4, forming a synergistic heat exchange structure to maximize the heat exchange area and improve cooling efficiency.

[0061] The side air inlet 2 is opened on the bottom side wall of the gas collection hood 1, and its opening angle is 15° to 30° with the side wall of the gas collection hood 1. It is used to guide the high temperature dust-containing chlorine gas escaping from the electrolytic cell 13 into the interior of the gas collection hood 1 in a tangential manner, thereby forming a stable swirling field. It uses inertial force to achieve the initial separation of coarse dust particles with a particle size greater than 5μm, reducing the subsequent dust removal load.

[0062] The multi-stage flow guide baffles 4 consist of at least three stages. Adjacent flow guide baffles 4 are staggered and fixed to the opposing inner walls of the gas collecting hood 1, forming an angle of 15° to 45° with the horizontal direction. This divides the internal cavity of the gas collecting hood 1 into a meandering S-shaped airflow channel, extending the residence time of chlorine gas within the gas collecting hood 1 and simultaneously increasing the contact area between chlorine gas and the flow guide baffles 4. The flow guide baffles 4 are made of a metal material with a thermal conductivity of not less than 100 W / (m·℃), and their surfaces are sandblasted to form a rough surface with a roughness Ra of 1.6 to 6.3 μm, enhancing the dust collision and capture effect and thermal conductivity efficiency. Their total heat exchange area is 3 to 5 times the area of ​​the inner wall of the gas collecting hood 1, ensuring that the heat exchange efficiency meets the heat exchange efficiency formula. The requirements, among which The value ranges from 80 to 120 W / (m²·℃). Select a size of 0.8 to 2.5 m² based on the specifications of gas collection hood 1. Select a flow rate of 0.05 to 0.2 kg / s. A heat exchange efficiency of 480 J / (kg·℃) is selected to ensure that the heat exchange efficiency η is not less than 85%.

[0063] Heat dissipation fins 5 are evenly arranged on the outer wall of the gas collection shroud 1. They are made of the same corrosion-resistant material as the gas collection shroud 1 and are distributed in a ring array with a spacing of 10 to 20 mm and a height of 30 to 50 mm. They are used to increase the natural convection heat transfer area between the gas collection shroud 1 and the air. The natural convection heat transfer coefficient between the fins and the air is 5 W / (m²·℃) to 10 W / (m²·℃), which realizes the secondary cooling of chlorine gas.

[0064] The forced cooling unit 6 has two implementation forms. The first is a cooling jacket surrounding the outside of the gas collection shroud 1, with a cooling medium inlet 7 and a cooling medium outlet 8. The cooling medium is industrial cooling water at a temperature of 20 to 30°C. The second is a fan assembly pointing towards the outer wall of the gas collection shroud 1, with 4 to 8 fans evenly distributed around the outer perimeter of the shroud 1. The forced cooling unit 6 is connected to the control system 10, which dynamically adjusts the operating parameters based on the monitoring signals from the temperature sensor 9.

[0065] The outlet pipe 3 is located at the top or upper part of the gas collection hood 1 and is connected to the subsequent chlorine compressor system. It is used to discharge the cooled and purified low-dust-content chlorine gas. The diameter of the outlet pipe 3 is matched with the volumetric flow rate of the chlorine gas to ensure that the chlorine gas flow rate is stable at 0.5 to 1.5 m / s, so as to avoid the dust from being re-entrained due to excessive flow rate.

[0066] The dust collection hopper 11 is located at the bottom of the gas collection hood 1 and has a conical structure with a cone angle of 30° to 60°, which facilitates the dust to slide down and settle under the action of gravity. The bottom of the dust collection hopper 11 is connected to the dust discharge valve 12, which has a double valve linkage structure to ensure the sealing of the gas collection hood 1 during the dust discharge process and prevent chlorine gas leakage.

[0067] Temperature sensor 9 is installed at outlet pipe 3 to monitor the temperature of outlet chlorine gas in real time with an accuracy of ±0.5℃. Its signal output terminal is connected to control system 10 to transmit real-time temperature data to control system 10.

[0068] Control system 10 adopts a PLC controller with a built-in PID control algorithm. The control formula is as follows: K The value ranges from 5 to 15. The value ranges from 10 to 30 seconds. The value ranges from 1 to 5 seconds, e(t) = T set -T meas T set The preset temperature is 60℃ to 70℃. meas Based on the real-time temperature monitored by temperature sensor 9, control system 10 dynamically adjusts the cooling intensity of forced cooling unit 6 according to temperature deviation e(t), with adjustment response time not exceeding 2s, to ensure that the outlet chlorine temperature is stable within the preset range and the absolute value of temperature deviation does not exceed 2℃.

[0069] Electrolytic cell 13 is a chlorine gas generating device. Its top is aligned with the gas collection hood 1 to ensure that all the high-temperature dust-laden chlorine gas escaping from electrolytic cell 13 can be collected by the gas collection hood 1, thus preventing chlorine gas leakage from causing environmental pollution and equipment corrosion.

[0070] like Figure 3 As shown, the method for achieving chlorine dust removal using the above-mentioned chlorine dust removal system specifically includes the following steps:

[0071] S1 Chlorine Collection: During the operation of the electrolytic cell 13, high-temperature dust-laden chlorine gas with a temperature of 200℃ to 300℃ and containing electrolyte dust such as magnesium chloride and calcium chloride is generated. Under the action of pressure difference, the chlorine gas enters the gas collection hood 1 through the side air inlet 2 at the bottom of the gas collection hood 1 at a tangential angle of 15° to 30°. The swirling flow field formed by the tangential air intake generates inertial centrifugal force. Coarse dust particles with a particle size greater than 5μm are thrown towards the inner wall of the gas collection hood 1 under the action of inertial force and slide down the inner wall to the dust collection hopper 11, realizing the initial inertial separation of coarse dust particles.

[0072] S2 three-stage synergistic cooling and dust removal:

[0073] S2a First-Stage Cooling and Dust Removal: After preliminary separation, the chlorine gas flows through an S-shaped meandering channel formed by multi-stage guide baffles 4. The chlorine gas velocity decreases from an initial 3m / s to 5m / s to 0.8m / s to 1.2m / s. The gas flow collides multiple times with the guide baffles 4, and heat exchange occurs simultaneously through the guide baffles 4. The heat exchange time is no less than 5s, and the chlorine temperature is initially reduced to 100℃ to 150℃. Some dust and gaseous chlorine condense and adhere on the surface of the guide baffles 4, achieving preliminary cooling and dust removal. The dust collision and collection efficiency of the guide baffles 4 satisfies the formula... ,in The value ranges from 0.3 to 0.8 m⁻¹. The effective collection area of ​​the flow guide baffle 4 is 0.6 to 2.0 m². The effective residence time of chlorine gas in gas collecting hood 1 satisfies the formula. Veffective is the effective volume of the airflow channel inside the gas collection hood 1 (0.5 to 1.5 m³), ​​Q is the volumetric flow rate of chlorine gas (0.3 to 1.0 m³ / s), and φ is the airflow channel contraction coefficient (0.4 to 0.7), so that the dust collision collection efficiency ε is not less than 75%.

[0074] S2b Secondary Cooling and Dust Removal: The heat carried by the chlorine gas is conducted through the wall of the gas collection hood 1 to the external heat dissipation fins 5. The heat dissipation fins 5 exchange heat with the surrounding air through natural convection, dissipating the heat into the air and achieving secondary cooling of the chlorine gas, further reducing the chlorine gas temperature to 80℃ to 120℃.

[0075] S2c three-stage precise cooling: The forced cooling unit 6 is activated to assist in cooling the gas collection hood 1. The control system 10 dynamically adjusts the operating parameters of the forced cooling unit 6 according to the outlet chlorine temperature monitored by the temperature sensor 9. If the forced cooling unit 6 is a cooling jacket, the cooling water flow rate is adjusted from 5 m³ / h to 20 m³ / h; if it is a fan assembly, the fan speed is adjusted from 1000 r / min to 3000 r / min to ensure that the chlorine temperature drops to the preset range of 60°C to 70°C. This temperature range is lower than the dew point temperature of magnesium chloride (about 100°C) and the dew point temperature of calcium chloride (about 120°C), which promotes the full condensation of gaseous chlorides into solid particles.

[0076] S3 Temperature Closed-Loop Control and Condensation: Temperature sensor 9 collects the chlorine temperature at outlet pipe 3 in real time and transmits the temperature data to control system 10. Control system 10 calculates the temperature deviation e(t) using a PID control algorithm and dynamically adjusts the cooling intensity of forced cooling unit 6 based on the deviation value, continuously and stably controlling the outlet chlorine temperature between 60℃ and 70℃. This prevents chlorine from re-vaporizing due to temperature fluctuations, ensuring that gaseous chlorine is fully condensed into solid particles, thus improving dust removal efficiency. Forced cooling unit 6 is equipped with a backup power supply with a battery life of no less than 2 hours, ensuring continuous temperature control even after power failure and preventing temperature runaway.

[0077] S4 Gas-Solid Separation and Conveying: Solid particles formed by condensation and dust adhering to the surface of the guide baffle 4 fall into the dust collection hopper 11 after gravity settling or airflow scouring. The settling time is not less than 8 seconds to ensure that the dust settles fully. The purified low-dust chlorine gas is discharged from the outlet pipe 3 and enters the subsequent chlorine compressor system to achieve dust-free conveying. The dust content of the purified chlorine gas is not higher than 10mg / m³, which meets the requirements of subsequent production.

[0078] S5 Dust Recovery: The ash discharge valve 12 is opened every 12 hours, with each opening lasting 10 to 30 seconds. During the ash discharge process, the opening and closing sequence of the two valves is maintained. First, the lower valve is opened to discharge ash. After the ash discharge is completed, the lower valve is closed. Then, the upper valve is opened to allow the dust in the ash collection hopper 11 to fall above the lower valve. The upper valve is then closed to complete one ash discharge operation, preventing the chlorine gas in the gas collection hood 1 from escaping. The discharged dust is directly discharged into the electrolytic cell 13 to achieve the recycling of electrolyte. The dust recovery rate of the system satisfies the formula η. d =(m c / m i )×100%, where m c To determine the mass of dust collected in ash hopper 11, m i The dust recovery rate η is the total mass of dust carried by the chlorine gas entering the gas collection hood 1. d No less than 90%.

[0079] To further clarify the technical solution of the present invention, verify its feasibility and practical application effects, the chlorine dust removal system and method of the present invention are described in detail below with reference to two specific embodiments. Each embodiment is only used to explain the present invention and does not constitute a limitation on the scope of protection of the present invention. In Embodiment 1, the forced cooling unit 6 is implemented as a cooling jacket, and in Embodiment 2, the forced cooling unit 6 is implemented as a fan assembly. Through specific parameter settings, operating procedures, and effect data, the advantages of the present invention in cooling, removing dust from, and recovering electrolytes in high-temperature dust-laden chlorine gas are intuitively demonstrated.

[0080] Example 1

[0081] In this embodiment, a cooling jacket is used as the forced cooling unit 6, and the specific parameters are as follows:

[0082] The gas collection shroud 1 is made of titanium alloy with a wall thickness of 10mm, an effective volume of 1.0m³, and an inner wall area of ​​0.6m². The side air inlet 2 is located on the bottom side wall of the gas collection shroud 1 with a tangential angle of 20°. The multi-stage flow guide baffle 4 consists of 3 stages, forming a 30° angle with the horizontal direction. It is made of copper alloy (thermal conductivity 120W / (m·℃)) with a surface roughness Ra3.2μm and a total heat exchange area of ​​2.0m² (3.3 times the inner wall area of ​​the gas collection shroud 1). The heat dissipation fins 5 are arranged in a ring array with a spacing of 15mm, a height of 40mm, and a quantity of 20 fins. The forced cooling unit 6 is a cooling jacket, and the cooling medium is 25℃ industrial cooling water; the outlet pipe 3 is located at the top of the gas collection hood 1, with a pipe diameter of 150mm; the ash collection hopper 11 has a conical structure with a cone angle of 45°; the ash discharge valve 12 is a double-valve linkage butterfly valve; the temperature sensor 9 has a monitoring accuracy of ±0.5℃; the PID parameters of the control system 10 are set to Kp10, Ti20s, and Td3s; the chlorine gas generated by the electrolytic cell 13 has a temperature of 250℃, a volumetric flow rate of 0.6m³ / s, a mass flow rate of 0.12kg / s, and carries a dust concentration of 800mg / m³.

[0083] Specific operational steps for dust removal methods to reduce chlorine content:

[0084] S1 Chlorine gas collection: High-temperature dust-laden chlorine gas at 250℃ enters the gas collection hood 1 through the side air inlet 2 at a tangential angle of 20°, forming a swirling flow field, initially separating coarse dust particles with a particle size greater than 5μm, and the coarse dust particles slide down to the dust collection hopper 11.

[0085] S2 Three-Stage Synergistic Cooling and Dust Removal: S2a First-Stage Cooling and Dust Removal, chlorine gas flows through an S-shaped channel formed by three-stage guide baffles 4, reducing the flow velocity from 4 m / s to 1.0 m / s, with a heat exchange time of 6 s. Taking φ0.55, the calculated tr = 1.0 / (0.6 × 0.55) ≈ 3.03 s, then according to... Take k c =0.5m -1A c =1.8m², calculated to be ε=1−exp(−0.5×1.8×3.03)≈92.3%, achieving initial cooling and dust removal, with chlorine temperature dropping to 120℃; S2b secondary cooling and dust removal, through natural convection heat exchange via heat dissipation fins 5, with chlorine temperature dropping to 90℃; S2c tertiary precise cooling, activating the cooling jacket, and introducing 25℃ industrial cooling water.

[0086] S3 Temperature Closed-Loop Control and Condensation: Temperature sensor 9 monitors the outlet chlorine temperature in real time. Control system 10 adjusts the cooling water flow rate according to the PID algorithm. The preset temperature is 65℃. When the monitored temperature is higher than 65℃, the cooling water flow rate is increased; when it is lower than 65℃, the cooling water flow rate is decreased. The adjustment response time is 1.5s, and the temperature deviation is controlled within ±1.5℃. The chlorine temperature is stabilized at around 65℃, and the gaseous chlorine is fully condensed.

[0087] S4 Gas-solid separation and conveying: The condensed solid particles settle into the dust collection hopper 11 after 8 seconds, and the purified chlorine gas is discharged from the outlet pipe 3 with a flow rate of 0.8 m / s and a dust content of 8 mg / m³.

[0088] S5 Dust Recovery: The ash discharge valve 12 is opened once every 12 hours, each time for 20 seconds, discharging ash according to the dual-valve linkage sequence. The discharged dust is then discharged into the electrolytic cell 13. Calculated =(0.6×0.12×3600×800×10 -6 ×90%) / (0.6×0.12×3600×800×10 -6 )×100%≈92%, which meets the dust recovery rate requirements.

[0089] In this embodiment, the heat exchange efficiency η is calculated according to the formula. Take K = 100 W / (m²·℃) =2.0m², m=0.12kg / s =480J / (kg·℃), calculated to be η=1−exp(−(100×2.0) / (0.12×480))≈96.8%, indicating good cooling and dust removal effects. The frequency of cleaning sublimation products from the chlorine main pipe was reduced from once every half month to once every three months, and the frequency of cleaning the rear bag filter was reduced from once a week to once a month.

[0090] Example 2

[0091] In this embodiment, a fan assembly is used as the forced cooling unit 6, and the specific parameters are as follows:

[0092] The gas collection hood 1 is made of polytetrafluoroethylene composite material with a wall thickness of 12mm, an effective volume of 1.2m³, and an inner wall area of ​​0.7m². The side air inlet 2 is located on the bottom side wall of the gas collection hood 1 at a tangential angle of 25°. The multi-stage flow guide baffle 4 consists of four stages, forming a 25° angle with the horizontal direction. It is made of aluminum alloy (thermal conductivity 110W / (m·℃)) with a surface roughness Ra=4.8μm and a total heat exchange area of ​​3.0m² (4.3 times the inner wall area of ​​the gas collection hood 1). (Multiple times); the heat dissipation fins 5 are arranged in a ring array with a spacing of 12mm, a height of 35mm, and a quantity of 24 fins; the forced cooling unit 6 is a fan group consisting of 6 fans, with a rated speed of 2800r / min for each fan; the outlet pipe 3 is located on the upper part of the gas collection shroud 1, with a pipe diameter of 160mm; the ash collection hopper 11 has a conical structure with a cone angle of 50°; the ash discharge valve 12 is a double-valve linked ball valve; the temperature sensor 9 has a monitoring accuracy of ±0.5℃; the PID parameters of the control system 10 are set to K p =12、T i =25s, T d =4s; The chlorine gas produced by electrolytic cell 13 has a temperature of 280℃, a volumetric flow rate of 0.8m³ / s, a mass flow rate of 0.16kg / s, and carries a dust concentration of 900mg / m³.

[0093] Specific operational steps for dust removal methods to reduce chlorine content:

[0094] S1 Chlorine gas collection: High-temperature dust-laden chlorine gas at 280℃ enters the gas collection hood 1 through the side air inlet 2 at a 25° tangential angle, forming a swirling flow field, initially separating coarse dust particles with a particle size greater than 5μm, and the coarse dust particles slide down to the dust collection hopper 11.

[0095] S2 Three-Stage Synergistic Cooling and Dust Removal: S2a First-Stage Cooling and Dust Removal, chlorine gas flows through an S-shaped channel formed by four-stage guide baffles, reducing the flow velocity from 4.5 m / s to 1.1 m / s, with a heat exchange time of 7 seconds, based on t r = Taking φ=0.6, we calculate t. r =1.2 / (0.8×0.6)=2.5s, then according to

[0096] ε=1−exp(−k c ·A c ·t r Let kc = 0.6m -1 Ac = 2.5 m²;

[0097] Calculated =1−exp(−0.6×2.5×2.5)≈97.7%, achieving initial cooling and dust removal, with the chlorine temperature dropping to 130℃; S2b secondary cooling and dust removal, through natural convection heat exchange via heat dissipation fins 5, the chlorine temperature drops to 95℃; S2c tertiary precise cooling, starting the fan assembly and adjusting the fan speed.

[0098] S3 Temperature Closed-Loop Control and Condensation: Temperature sensor 9 monitors the outlet chlorine temperature in real time. Control system 10 adjusts the fan speed according to the PID algorithm. The preset temperature is 62℃. When the monitored temperature is higher than 62℃, the fan speed is increased; when it is lower than 62℃, the fan speed is decreased. The adjustment response time is 1.8s. The temperature deviation is controlled within ±1.8℃. The chlorine temperature is stabilized at around 62℃, and the gaseous chlorine is fully condensed.

[0099] S4 Gas-solid separation and conveying: The condensed solid particles settle into the dust collection hopper 11 after 9 seconds, and the purified chlorine gas is discharged from the outlet pipe 3 at a flow rate of 1.0 m / s and a dust content of 7 mg / m³.

[0100] S5 Dust Recovery: The ash discharge valve 12 is opened once every 12 hours for 25 seconds each time. The ash is discharged in the order of the two valves in linkage. The discharged dust is discharged into the electrolytic cell 13. According to ηd=(mc / mi)×100%, ηd≈93.5% is calculated, which meets the dust recovery rate requirements.

[0101] In this embodiment, the heat exchange efficiency η is calculated according to the formula. ,Pick =95W / (m²·℃) =3.0m² =0.16kg / s =480J / (kg·℃), calculated as follows:

[0102] η=1−exp(−(95×3.0) / (0.16×480))≈98.2%;

[0103] It has excellent cooling and dust removal effects. The frequency of cleaning sublimation products from the chlorine main pipe has been reduced from once every half month to once every 3.5 months, and the frequency of cleaning the rear bag filter has been reduced from once a week to more than once a month.

[0104] The dust removal method for reducing chlorine content in this invention synergistically enhances the system's cooling and dust removal capabilities, resulting in significant and stable purification effects. It addresses the technical pain points of existing chlorine dust removal technologies, such as incomplete cooling, low dust collection efficiency, and difficulty in effectively removing gaseous chlorides. This invention utilizes a swirling flow field formed by a gas collection hood and side inlets to achieve initial inertial separation of coarse dust particles. Combined with an S-shaped meandering channel constructed from multi-stage guide baffles, this extends the chlorine residence time and increases the heat exchange and collision area. Coupled with natural convection heat exchange from heat dissipation fins and precise cooling from a forced cooling unit, a three-stage synergistic cooling system is formed, achieving a heat exchange efficiency of no less than 85%. This system can stably reduce high-temperature chlorine to a preset range of 60°C to 70°C, below the dew point temperature of magnesium chloride and calcium chloride, thus promoting the full condensation of gaseous chlorides into solid particles. Meanwhile, the rough surface of the baffle plate treated by sandblasting and the reasonable angle design, combined with the optimization of dust collision collection efficiency parameters, make the dust collision collection efficiency no less than 75%, ultimately achieving a dust content of no more than 10mg / m³ in the purified chlorine gas and a dust recovery rate of no less than 90%, which is significantly better than existing dust removal technologies and effectively avoids wear and blockage of the subsequent chlorine compressor system by dust and gaseous chlorides.

[0105] The chlorine dust removal system of this invention is stable, reliable, and highly safe, with low maintenance costs and a long service life, making it suitable for large-scale industrial production. This invention specifically optimizes the structure and materials of each component. The gas collection hood uses chlorine-resistant titanium alloy or polytetrafluoroethylene composite material with a wall thickness controlled between 8 and 15 mm, capable of withstanding high-temperature corrosion environments of 200℃ to 300℃, and has a service life of no less than 5 years. The ash discharge valve adopts a dual-valve linkage structure to effectively prevent chlorine leakage and ensure production safety. The control system uses a PID closed-loop regulation algorithm, combined with high-precision monitoring by a temperature sensor, with an adjustment response time of no more than 2 seconds, controlling the outlet chlorine temperature deviation within ±2℃, avoiding chlorine re-vaporization caused by temperature fluctuations, and ensuring system operational stability. Furthermore, this invention incorporates a dust recovery and recycling design, directly discharging the collected electrolyte dust into the electrolytic cell, reducing resource waste and significantly reducing the maintenance frequency of downstream equipment. The frequency of cleaning sublimation from the chlorine main pipe is reduced from once every two weeks to more than three months, and the frequency of cleaning the downstream bag filter is reduced from once a week to more than once a month, significantly reducing labor and material costs.

[0106] The dust removal method and system for reducing chlorine content in this invention are energy-saving, environmentally friendly, and highly adaptable. This invention employs a staged cooling mode combining natural heat dissipation and forced cooling. The heat dissipation fins increase the natural convection heat transfer area, and the forced cooling unit can be implemented using either a cooling jacket or a fan assembly, adapting to different scales of chlorine production scenarios. Compared to existing single cooling modes, energy consumption is reduced by more than 15%, aligning with the industrial development trend of energy conservation and environmental protection. Simultaneously, this invention utilizes a synergistic dust removal mechanism of cyclone separation, collision capture, and condensation sedimentation, eliminating the need for additional dust removal agents and avoiding secondary pollution from agent use. Furthermore, the high dust recovery rate reduces both electrolyte waste and the environmental impact of dust emissions.

[0107] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dust removal system for reducing chlorine content, characterized in that, include: A gas collection hood (1) is installed above the chlorine electrolysis cell (13) to collect high-temperature dust-containing chlorine gas generated by the electrolysis cell (13); A side air inlet (2) is provided on the bottom side wall of the gas collection hood (1) to guide high-temperature dust-laden chlorine gas into the gas collection hood (1) in a tangential manner and form a swirling flow to achieve the initial inertial separation of coarse dust particles; Multi-stage flow guide baffles (4) are staggered in the internal cavity of the gas collection hood (1) to divide the airflow channel inside the gas collection hood (1) into a meandering S-shaped path; The heat dissipation structure consists of several heat dissipation fins (5) disposed on the outer wall of the gas collection shroud (1) to increase the natural convection heat dissipation area; the forced cooling unit (6) acts on the gas collection shroud (1) to provide auxiliary cooling; The outlet pipe (3) is located at the top or upper part of the gas collection hood (1) and is used to discharge the cooled and purified chlorine gas. A dust collection hopper (11) is located at the bottom of the gas collection hood (1) and is used to collect settled solid dust particles. Ash discharge valve (12) is located at the bottom of the ash collection hopper (11) and is used to discharge the collected dust; temperature sensor (9) is located at the outlet pipe (3) and is used to monitor the real-time temperature of the outlet chlorine gas. The control system (10) is connected to the temperature sensor (9) and the forced cooling unit (6) for dynamically adjusting the cooling intensity; The system enhances heat transfer through the synergistic effect of multi-stage flow guide baffles (4) and heat dissipation fins (5), and its heat transfer efficiency satisfies the following formula: ； In the formula, The heat exchange efficiency between chlorine gas and the gas collecting hood (1); The combined heat transfer coefficient of the gas collection hood (1) wall and the multi-stage flow guide baffle (4) is expressed in W / (m²). 2 ·℃); The total heat exchange area of ​​the multi-stage flow guide baffle (4) and the inner wall of the gas collection hood (1) is expressed in m². 2 ; This is the mass flow rate of chlorine gas, in units of... ; This is the isobaric specific heat capacity of chlorine gas, expressed in J / (kg·℃).

2. The dust removal system for reducing chlorine content according to claim 1, characterized in that, The multi-stage flow guide baffles (4) are at least three stages. Adjacent flow guide baffles (4) are staggered and fixed on the relative inner walls of the gas collection hood (1). The flow guide baffles (4) are at an angle of 15°-45° to the horizontal direction, which is used to extend the airflow path and enhance the heat exchange efficiency.

3. The dust removal system for reducing chlorine content according to claim 2, characterized in that, The flow guide baffle (4) is made of a metal material with a thermal conductivity of not less than 100 W / (m·℃). The end of the flow guide baffle (4) is thermally connected to the inner wall of the gas collecting hood (1), and the surface of the flow guide baffle (4) is sandblasted to form a roughness. A rough surface with a thickness of 1.6-6.3 μm; The collision and dust collection efficiency of the flow guide baffle (4) satisfies the following formula: ； In the formula, To improve dust collision and collection efficiency; The dust collision coefficient on the surface of the baffle (4) is expressed in m. -1 ; The effective capture area of ​​the flow guide baffle (4) is expressed in m². 2 ; The effective residence time of chlorine gas in the gas collecting hood (1) is expressed in units of 1. .

4. The dust removal system for reducing chlorine content according to claim 1, characterized in that, The forced cooling unit (6) is a cooling jacket surrounding the outside of the air collecting shroud (1), and the cooling jacket is provided with a cooling medium inlet (7) and a cooling medium outlet (8); or the forced cooling unit (6) is a fan assembly pointing towards the outer wall of the air collecting shroud (1); The control system (10) uses a PID algorithm to adjust the flow rate of the cooling medium or the fan speed. The adjustment formula is as follows: ； In the formula, The output of the cooling unit is adjusted. This is the proportionality coefficient; This is the temperature deviation value. , For preset temperature, This is the measured temperature; The integral time constant; is the differential time constant.

5. The dust removal system for reducing chlorine content according to claim 4, characterized in that, The preset temperature The temperature range is 60℃ to 70℃, which is lower than the dew point temperatures of magnesium chloride and calcium chloride, ensuring sufficient condensation of gaseous chlorides; the monitoring accuracy of the temperature sensor (9) is ±0.5℃, the adjustment response time of the control system (10) does not exceed 2s, and the temperature deviation value after adjustment is... The absolute value should not exceed 2℃ to avoid the chloride from re-vaporizing due to temperature fluctuations.

6. The dust removal system for reducing chlorine content according to claim 1, characterized in that, The dust collection hopper (11) has a conical structure with a cone angle of 30°-60°, which facilitates the downward sliding and settling of dust; the dust discharge valve (12) has a double valve linkage structure, which is used to prevent chlorine gas leakage in the gas collection hood (1); The dust recovery rate of the system satisfies the following formula: ； In the formula, Dust recovery rate; The mass of dust collected by the dust collection hopper (11) is expressed in units of... ; The total mass of dust carried by the chlorine gas entering the gas collection hood (1) is expressed in units of 1. And the dust recovery rate No less than 90%.

7. The dust removal system for reducing chlorine content according to claim 1, characterized in that, The gas collection hood (1) is made of chlorine-resistant titanium alloy or polytetrafluoroethylene composite material. The wall thickness of the gas collection hood (1) is 8-15mm. It can withstand the high temperature corrosion environment above the electrolytic cell (13) and has a service life of not less than 5 years.

8. A dust removal method for reducing chlorine content using the system described in claim 1, characterized in that, Includes the following steps: S1: Chlorine gas collection. High-temperature chlorine gas with a temperature of 200℃-300℃, carrying electrolyte dust such as magnesium chloride and calcium chloride, escapes from the electrolytic cell (13). It enters the gas collection hood (1) at a tangential angle of 15°-30° through the side air inlet (2) at the bottom of the gas collection hood (1) to form a swirling flow field. The inertial force is used to achieve the initial separation of coarse dust particles with a particle size greater than 5μm. S2: Three-stage synergistic cooling and dust removal, including: S2a: Primary cooling and dust removal. Chlorine gas flows through an S-shaped meandering channel formed by multi-stage flow guide baffles (4). The flow velocity drops from the initial 3m / s-5m / s to 0.8m / s-1.2m / s. The airflow collides and conducts heat exchange with the flow guide baffles (4) multiple times. The heat exchange time is not less than 5s. Some dust and gaseous chloride condense and adhere to the surface of the baffles, achieving preliminary cooling and dust removal. S2b: Secondary cooling and dust removal. The heat carried by chlorine is conducted to the external heat dissipation fins (5) through the wall of the gas collection hood (1). The heat transfer coefficient between the fins and the air through natural convection is 5W / (m²·℃)-10W / (m²·℃). Secondary cooling is achieved through natural convection. S2c: Three-stage precise cooling, the forced cooling unit (6) is activated to provide auxiliary cooling to the gas collection hood (1), and the cooling intensity is adjusted in real time according to the outlet temperature; S3: Temperature closed-loop control and condensation. The chlorine temperature at the outlet pipe (3) is collected in real time by the temperature sensor (9). The control system (10) dynamically adjusts the operating parameters of the forced cooling unit (6) based on the temperature feedback signal, and stably controls the outlet chlorine temperature within the preset range, so that the chlorine temperature is lower than the dew point temperature of gaseous chlorides such as magnesium chloride and calcium chloride, so as to promote the full condensation of gaseous chlorides into solid particles. S4: Gas-solid separation and conveying. Solid particles formed by condensation and dust adhering to the surface of the guide baffle (4) fall into the dust collection hopper (11) after gravity settling or airflow scouring. The settling time is not less than 8s. The purified low-dust chlorine gas is discharged from the outlet pipe (3) and enters the subsequent chlorine compressor system to achieve dust-free conveying. S5: Dust recovery, periodically open the ash discharge valve (12) to discharge the dust collected in the ash collection hopper (11) directly into the electrolytic cell (13) to realize the recycling of electrolyte; In step S3, the effective residence time of chlorine gas in the gas collecting hood (1) satisfies the following formula: ； In the formula, The effective residence time of chlorine gas in the gas collecting hood (1) is expressed in units of 1. ; The effective volume of the airflow channel inside the gas collection hood (1) is expressed in m³. 3 ; This is the volumetric flow rate of chlorine gas, in m³ / s. 3 / s; The value of is the airflow channel contraction coefficient caused by the baffle (4), which ranges from 0.4 to 0.

7.

9. The dust removal method for reducing chlorine content according to claim 8, characterized in that, In step S3, the chlorine temperature of the outlet pipe (3) is monitored in real time, and the operating parameters of the forced cooling unit (6) are fed back. If the forced cooling unit (6) is a cooling jacket, the cooling water flow rate is adjusted to 5 m³ / h-20 m³ / h. If it is a fan group, the fan speed is adjusted to 1000 r / min-3000 r / min. The forced cooling unit (6) is equipped with a backup power supply with a backup power supply capacity of not less than 2 hours to ensure that the temperature control continuity can still be maintained after power failure. The outlet chlorine temperature is stably controlled between 60°C and 70°C to meet the feed temperature requirements of the downstream chlorine compressor system. This reduces the frequency of cleaning sublimation products from the chlorine main pipe from once every half month to once every three months, and the frequency of cleaning the downstream bag filter from once a week to once a month.

10. The dust removal method for reducing chlorine content according to claim 8, characterized in that, In step S5, the ash discharge valve (12) is opened once every 12 hours, and each opening lasts for 10-30 seconds. During the ash discharge process, the opening and closing sequence of the two valves is maintained. First, the lower valve is opened to discharge ash. After the ash discharge is completed, the lower valve is closed. Then, the upper valve is opened to allow the dust in the ash collection hopper (11) to fall, so as to prevent the chlorine gas in the gas collection hood (1) from escaping.

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