High-temperature high-chlorine flue gas treatment device

Abstract

The utility model discloses a high-temperature high-chlorine flue gas treatment device, which belongs to the field of flue gas treatment and comprises a cooling system, the cooling system is connected with an absorption tower, a cooling section is connected with a flue gas inlet pipe at the upper part and an arc-shaped obliquely downward connecting flue at the lower part, and the diameter of the cooling section is larger than that of the flue gas inlet pipe and that of the connecting flue; a turbulent flow module is arranged above the flue gas inlet of the absorption tower, and the turbulent flow module is composed of a plurality of cones of which the tips are oppositely arranged and are communicated with each other. According to the utility model, through reasonable arrangement, the harm of chloride ions to the treatment device is weakened. The turbulent flow module is arranged, so that flue gas and slurry are fully mixed and reacted, and the reaction efficiency is ensured.

Description

Technical Field

[0001] This utility model relates to the field of flue gas treatment technology, and in particular to a high-temperature, high-chlorine flue gas treatment device. Background Technology

[0002] Existing scrubbing towers have significant shortcomings in gas-liquid mixing. Traditional scrubbing towers typically use packing layers or spraying to achieve gas-liquid contact, but due to the unidirectional flow of gas and liquid, the mixing effect is limited, easily leading to airflow short-circuiting or localized uneven mixing. This insufficient mixing reduces the reaction efficiency between flue gas and slurry, thus affecting the overall purification effect.

[0003] Chinese Patent Publication No. CN219942364U, Publication Date: November 3, 2023, discloses a Chinese patent entitled "A Flue Gas Purification Scrubber Tower." This scrubber tower consists of a cooling device and a dehumidification device. The lower part of the scrubber tower is the cooling device, and the upper part is the dehumidification device. The cooling device includes a flue gas inlet, a cooling spray layer, a first-stage demister, a coolant outlet, and a coolant slurry pool. The dehumidification device includes a dehumidification liquid collection layer, a dehumidification liquid packing layer, a dehumidification spray layer, a second-stage demister, a flue gas outlet, and a dehumidification liquid outlet. In this device, the slurry mixes with the flue gas only through spraying, which leads to uneven gas-liquid mixing and affects reaction efficiency. Utility Model Content

[0004] This invention provides a high-temperature, high-chlorine flue gas treatment device. By setting up a turbulent flow module, the flue gas and slurry are fully mixed and reacted, ensuring reaction efficiency.

[0005] A further objective of this invention is to provide a device that can maintain processing efficiency and generate byproducts normally under high temperature and high chlorine conditions by adjusting the materials of each system.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a high-temperature, high-chlorine flue gas treatment device. It includes a cooling system connected to an absorption tower. The cooling section is connected to a flue gas inlet pipe at the top and to a downward-sloping, arc-shaped connecting flue at the bottom. The diameter of the cooling section is larger than that of the flue gas inlet pipe and the connecting flue. The absorption tower has a turbulence module above the flue gas inlet, the turbulence module consisting of several interconnected cones with their tips facing each other.

[0007] Preferably, the cooling section is equipped with a cooling spray system, connected at the bottom to the top of the flue gas duct via a flange. When the flue gas enters the cooling section, which has a diameter larger than the flue gas inlet pipe, its flow velocity decreases. Water mist with a diameter of 1-3 mm is sprayed through the cooling spray system, reacting with the high-temperature flue gas and evaporating, absorbing heat from the flue gas and thus achieving rapid cooling. The cooling section uses a larger diameter than the flue gas inlet pipe, further reducing the flue gas velocity in this area and producing a better cooling effect. This design not only effectively reduces the flue gas temperature but also reduces the operating load on the subsequent absorption tower, improving the overall energy efficiency of the system. Simultaneously, it avoids thermal shock to the equipment due to high temperatures, extending the equipment's service life.

[0008] Preferably, the bottom end of the flue connects to the flue gas inlet of the absorption tower. The cooled flue gas enters the absorption tower through the lower flue connection. After entering the absorption tower system, the flue gas flows upwards against the slurry, while the downstream slurry, at the turbulence module, experiences turbulence due to the change in the channel cross-section. The high-speed impact between the two at this point causes dispersion and atomization, thus ensuring thorough mixing and reaction of the flue gas and slurry. The flue gas is inserted into the absorption tower in an arc-shaped, downward-sloping design, preventing water droplets generated by the spray from accumulating in the flue. This arc-shaped, downward-sloping flue design not only optimizes the gas-liquid flow path but also avoids water droplet deposition, reducing the risk of equipment blockage.

[0009] Preferably, a pulse stirring device is installed at the bottom of the absorption tower to prevent gypsum deposition. The pulse stirring device prevents the most susceptible side stirring blades from being corroded by chloride ions. The pulse stirring device not only prevents gypsum deposition and avoids equipment blockage, but also reduces mechanical wear and lowers equipment maintenance costs through intermittent stirring, while simultaneously enhancing the system's corrosion resistance.

[0010] Preferably, the absorption tower has several spray layers above the turbulence module. With multiple spray layers at the top inside the absorption tower, the flue gas continues to flow counter-currently through the turbulence module, mixing and reacting with the slurry sprayed from the three spray layers. This multi-layer spray design further enhances the gas-liquid contact area and reaction time, improving flue gas purification efficiency while reducing the emission of unreacted flue gas, thus improving the system's environmental performance.

[0011] Preferably, an airflow distribution grid, made of fiberglass, is installed between the top two spray layers. An airflow distribution grid is also installed between the second and third spray layers to ensure uniform airflow within the absorption tower. The fiberglass grid ensures uniform airflow distribution and is not easily corroded. The installation of the airflow distribution grid ensures uniform airflow distribution within the tower, avoiding insufficient local gas-liquid contact, further improving reaction efficiency. Simultaneously, the use of fiberglass enhances the equipment's corrosion resistance.

[0012] Preferably, several spray layers are connected to a circulating pump on one side of the absorption tower via circulation pipes. The circulating pump is made of engineering plastic. The use of engineering plastic pumps is intended to handle high-chlorine slurry and prevent chloride ion corrosion. The use of engineering plastic pumps effectively solves the problem of equipment corrosion in high-chlorine environments, extends the service life of the circulating pump, reduces equipment replacement costs, and ensures stable system operation.

[0013] Preferably, a demister layer is installed above several spray layers. The demister is a ridge-type demister, with a collection tray below. The flue gas, after passing through the spray layers, passes through the demister layer to remove small gypsum particles and acid mist droplets before being discharged to the downstream wet electrostatic precipitator system. The collection tray at the bottom recovers some of the flushing water, reducing wastewater discharge. The ridge-type demister design effectively removes fine particles and acid mist droplets from the flue gas, improving its cleanliness. Simultaneously, the collection tray reduces wastewater discharge and lowers environmental treatment costs.

[0014] Preferably, the absorption tower is constructed entirely of fiberglass reinforced plastic (FRP), with a reinforced anti-corrosion layer installed at the inlet. A FRP reinforcement layer is installed 2 meters above and below the inlet of the flue gas to prevent corrosion. The extensive use of FRP effectively resists corrosion in high-temperature and high-chlorine environments, enhancing the overall durability of the equipment.

[0015] Preferably, the cooling section is made of carbon steel and lined with 50mm of acid and alkali resistant castable to prevent corrosion from the equipment by a mixture of water and flue gas. The connecting flue is made of high-temperature resistant fiberglass. By rationally arranging the anti-corrosion layer and acid and alkali resistant castable, the corrosion resistance of the equipment is further improved, and the equipment maintenance cost is reduced.

[0016] The beneficial effects of this invention are as follows: All parts in contact with chloride ions are made of fiberglass or plastic to prevent corrosion. A reasonable layout reduces the harmful effects of chloride ions on the treatment device. Multiple design features ensure the absorption efficiency of a single tower without significantly increasing equipment costs, and minimize wastewater discharge during operation. The inclusion of a turbulent flow module ensures thorough mixing and reaction of the flue gas and slurry, guaranteeing reaction efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the cooling system of the present invention.

[0019] Figure 3 for Figure 1 Enlarged view of point A.

[0020] Attached reference numerals: 1: Cooling section, 2: Connecting flue, 3: Turbulent flow module, 4: Spray layer, 5: Airflow distribution grid, 6: Demister layer, 7: Pulse stirring device, 8: Absorption tower, 9: Flue gas inlet pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] Because the flue gas from hazardous waste disposal is highly corrosive, the temperature is raised to over 220°C to protect the upstream baghouse dust collector. Excessive temperature can damage the deacidification tower; therefore, a flue gas cooling device is added before the tower. Furthermore, due to the presence of chlorine-containing materials in the hazardous waste, the entire flue gas treatment system operates in a high-chlorine environment for extended periods. Existing conventional limestone treatment systems encounter problems such as equipment corrosion, reduced deacidification efficiency, and inability to generate byproducts properly when faced with high-chlorine flue gas.

[0023] All parts of this device that come into contact with chloride ions are made of fiberglass or plastic to prevent corrosion. The reasonable layout reduces the harm of chloride ions to the treatment device. Multiple designs ensure the absorption efficiency of a single tower without increasing the cost of the device excessively, and minimize the amount of wastewater discharged during operation.

[0024] Traditional wet flue gas desulfurization (FGD) devices (such as spray towers and packed towers) generally employ unidirectional slurry spraying or turbulent contact methods, which have the following key drawbacks: First, the mixing efficiency between flue gas and slurry is low. Due to the limitations of fluid dynamics, it is difficult to achieve uniform dispersion of the gas and liquid phases at the microscale, resulting in incomplete desulfurization reactions and requiring additional slurry circulation or extended reaction time. Second, the slurry has a single flow path and a small velocity gradient within the tower, easily forming stratification or local stagnation zones, causing the deposition and scaling of solid particles (such as gypsum crystals and impurities), leading to problems such as pipe blockage and nozzle failure, forcing frequent equipment shutdowns for cleaning. Third, traditional designs have high energy consumption, especially in the slurry transportation and mixing stages, where power consumption accounts for a significant proportion of operating costs. Furthermore, the gas-liquid contact time within the tower is limited by the fluid dynamic structure, further restricting the ability to treat high-concentration pollutants.

[0025] This device overcomes the aforementioned technical bottlenecks through an innovative counter-current / co-current coupled flow mechanism and a turbulent flow module 3 in the bottom liquid collection cone. By dynamically counteracting the reverse airflow and the forward slurry, combined with the abrupt change effect of the cone cross-section, the turbulent kinetic energy and dispersion of the gas and liquid phases can be significantly improved, achieving instantaneous mixing and rapid reaction. This reduces slurry consumption and equipment resistance while ensuring desulfurization efficiency. At the same time, the strong turbulent scouring effect effectively inhibits particulate matter deposition, reduces maintenance frequency and energy consumption, and provides a better technical path for the efficient purification of industrial flue gas.

[0026] like Figure 1 As shown, this high-temperature, high-chlorine flue gas treatment device mainly consists of two core parts: a cooling system and an absorption tower 8. The cooling system, as the first treatment stage after the flue gas enters the device, plays a crucial role. It connects the flue gas inlet pipe 9 and the absorption tower 8. The cooling section 1 is connected to the flue gas inlet pipe 9 at the top and to the downward-sloping arc-shaped connecting flue duct 2 at the bottom. The diameter of the cooling section 1 is intentionally designed to be larger than that of the flue gas inlet pipe 9 and the connecting flue duct 2; this unique design lays a solid foundation for the subsequent cooling process.

[0027] Absorption tower 8 is the key area for achieving flue gas purification. Above the flue gas inlet of absorption tower 8, there is a turbulence module 3, which is the core component that promotes the thorough mixing and reaction of flue gas and slurry. Absorption tower 8 also has multiple spray layers 4, airflow distribution grid layer, demister layer 6, etc., and all components work together to ensure that the flue gas is deeply purified.

[0028] like Figure 2 As shown, a cooling spray system is installed in the cooling section 1, with its bottom end securely connected to the top of the connecting flue duct 2 via a flange. When high-temperature, high-chlorine flue gas enters the cooling section 1 from the flue gas inlet pipe 9, the flue gas velocity drops rapidly due to the increased diameter of the cooling section 1. At this time, the cooling spray system starts working, spraying out fine water mist with a diameter of 1-3 mm. These water mists, upon contact with the high-temperature flue gas, quickly absorb heat from the flue gas and evaporate, thus achieving rapid cooling of the flue gas. This reduces thermal shock to the equipment and effectively reduces the heat load on subsequent equipment such as the absorption tower 8. The cooling section 1 uses a larger diameter than the flue gas inlet pipe, reducing the flue gas velocity, which not only improves the cooling effect but also reduces equipment wear. This reduces the frequency of equipment maintenance and significantly lowers maintenance costs.

[0029] In traditional flue gas treatment systems, the design of the flue duct is often relatively simple, typically a straight line or vertically inserted into the absorption tower. However, this design has a significant drawback: when the spray system is operating, the sprayed water mist cools rapidly and condenses into water droplets upon contact with the high-temperature flue gas. These droplets accumulate on the inner wall of the flue, easily forming droplet deposits. Over time, these deposits gradually increase, eventually leading to flue blockage. Once the flue is blocked, the flow path of the flue gas is obstructed, not only affecting the normal operation of the system but also increasing the system's operating resistance, reducing treatment efficiency, and potentially even causing equipment failure, increasing maintenance costs and downtime.

[0030] The connecting flue 2 of this invention adopts an arc-shaped, downward-sloping insertion into the absorption tower 8. This design optimizes the gas-liquid flow path, allowing for smoother separation of flue gas and water droplets as they enter the absorption tower 8. The arc-shaped, downward-sloping structure allows water droplets to slide naturally down the inner wall of the flue under gravity, rather than accumulating inside. Simultaneously, this design utilizes the kinetic energy of the flue gas, creating a certain swirling flow as it enters the absorption tower 8, further promoting the separation of water droplets from the flue gas and reducing the residence time of water droplets within the flue, thus effectively preventing water droplet deposition. The cooled flue gas enters the absorption tower 8 through the lower connecting flue 2. The ingenious design of the connecting flue 2, with its arc-shaped, downward-sloping insertion into the absorption tower 8, effectively prevents water droplets generated by spraying from depositing in the flue. The arc-shaped, downward-sloping flue design of this device optimizes the gas-liquid flow path, ensuring stable system operation.

[0031] like Figure 1 and Figure 3 As shown, the turbulence module 3 installed above the flue gas inlet of the absorption tower 8 consists of several cones with their tips facing each other and connected. In this embodiment, two cones are preferably arranged symmetrically. When the cooled flue gas enters the absorption tower 8 system, it flows upwards against the current. Simultaneously, the slurry flowing downwards experiences turbulence at the turbulence module 3 due to the change in the channel cross-section. The high-speed impact between the flue gas and slurry at this point causes them to disperse and atomize, thus achieving thorough mixing and reaction. This significantly improves the reaction efficiency. After installing the turbulence module 3, the mixing of flue gas and slurry is more complete, improving the pollutant removal rate and reducing pollutant emissions.

[0032] The bottom of the absorption tower 8 is equipped with a pulse stirring device 7, the main function of which is to prevent gypsum deposition. In high-temperature and high-chlorine environments, traditional side-stirring blades are easily corroded by chloride ions. However, the pulse stirring device 7, through intermittent stirring, not only effectively prevents gypsum deposition and avoids equipment blockage, but also reduces mechanical wear. This extends the equipment maintenance cycle, reduces equipment maintenance costs, and enhances the system's corrosion resistance.

[0033] The absorption tower 8 has several spray layers 4 above the turbulent flow module 3. In this embodiment, three spray layers 4 are preferably provided. After the flue gas passes through the turbulent flow module 3, it continues to flow upwards in a countercurrent manner, further mixing and reacting with the slurry sprayed from the three spray layers 4. The design of multiple spray layers 4 greatly increases the gas-liquid contact area and reaction time, significantly improving the flue gas purification efficiency.

[0034] Between the top two spray layers 4, an airflow distribution grid layer is provided, and this grid layer is made of fiberglass. In this embodiment, the airflow distribution grid layer between the second and third spray layers 4 effectively ensures uniform airflow distribution within the absorption tower 8. This significantly improves the flue gas purification effect and increases treatment efficiency. The use of fiberglass not only ensures uniform airflow distribution but also enhances the equipment's corrosion resistance and extends its service life.

[0035] Several spray layers 4 are connected to a circulating pump on one side of the absorption tower 8 via circulation pipes. The circulating pump is made of engineering plastic. In the high-temperature, high-chlorine slurry environment, ordinary metal circulating pumps are highly susceptible to chloride ion corrosion, leading to equipment damage. However, the engineering plastic pump, with its excellent corrosion resistance, can effectively cope with high-chlorine slurries. This extends the service life of the circulating pump, reduces equipment replacement costs, and ensures stable system operation.

[0036] A demister layer 6 is installed above several spray layers 4. The demister is a ridge-type demister with a collection tray below. The flue gas treated by the spray layers 4 carries small gypsum particles and acid mist droplets. The ridge-type demister effectively removes these impurities, improving the cleanliness of the flue gas. The collection tray can recover some of the flushing water, reducing wastewater discharge. In actual operation, the flushing water recovered by the collection tray can be directly reused in the system, reducing water waste and wastewater treatment costs.

[0037] The absorption tower 8 is constructed entirely of fiberglass reinforced plastic (FRP), with a reinforced anti-corrosion layer installed 2 meters above and below the inlet. FRP possesses excellent corrosion resistance, effectively resisting the erosion of high-temperature and high-chlorine environments. Using FRP for the absorption tower 8 significantly improves corrosion resistance and extends the equipment's service life. The reinforced anti-corrosion layer at the inlet further enhances the equipment's corrosion resistance, ensuring stable operation even in harsh environments.

[0038] As a crucial component of the flue gas treatment system, the cooling and heat dissipation section 1's structural design and material selection directly impact the overall system's operational efficiency and equipment lifespan. The main body of this section is constructed from Q235B carbon steel with a thickness of 12mm, and its inner surface is covered with a 50mm thick protective layer of acid- and alkali-resistant castable refractory. This castable refractory is made from high-quality high-alumina cement, silica fume, and acid-resistant aggregate in a specific ratio. Testing has shown that it remains stable in strong acid and alkali environments with pH values ​​of 1-14, achieving a compressive strength of 45MPa and an operating temperature of up to 800℃. This dual-protection design effectively prevents corrosion from acidic liquids (pH 2-4) formed by the mixture of water and flue gas, extending the equipment's service life under harsh conditions by 3-5 times and reducing annual maintenance frequency from 6-8 times to 1-2 times.

[0039] The connecting flue section 2 is made of high-temperature resistant fiberglass (FRP), a composite material composed of a specially formulated vinyl ester resin and high-temperature resistant glass fiber. Its long-term operating temperature can reach 180℃, and its short-term temperature resistance can reach 220℃. The flue wall thickness is designed to be 10mm, manufactured using a cross-winding process to ensure its circumferential tensile strength is not less than 200MPa. This material selection ensures both the structural stability of the flue in high-temperature flue gas environments (150-180℃) and enhances its corrosion resistance. Tests have shown that it performs well in sulfur-containing flue gas (SO2 concentration 2000mg / Nm³). 3 The annual corrosion rate in the environment is less than 0.05 mm. Meanwhile, the inner surface smoothness of the fiberglass material reaches Ra0.2 μm, effectively reducing flue gas flow resistance, ensuring smooth flue gas transport, reducing system pressure loss by approximately 15%, and decreasing annual operating energy consumption by 8%-10%. This optimized design not only improves system reliability but also significantly reduces operating and maintenance costs, resulting in significant economic benefits.

[0040] This utility model uses fiberglass or plastic for all parts in contact with chloride ions to prevent corrosion. The reasonable arrangement reduces the harm of chloride ions to the treatment device. Through multiple designs, the absorption efficiency of a single tower is guaranteed without increasing the cost of the device excessively, and the amount of wastewater discharged during operation is minimized.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this utility model.

Claims

1. A high-temperature high-chlorine flue gas treatment device, characterized in that, It comprises a cooling system, the cooling system is connected with the absorption tower, the cooling section is connected with the flue gas inlet pipe at the top and the arc downward connecting flue at the bottom, the diameter of the cooling section is larger than that of the flue gas inlet pipe and the connecting flue; The absorption tower is provided with a turbulence module above the flue gas inlet, the turbulence module is composed of a plurality of cone bodies arranged oppositely at the tip and connected.

2. A high temperature high-chloride fume treatment device according to claim 1, characterized in that, A cooling spray system is arranged in the cooling section, and the bottom end is connected with the top end of the connecting flue through a flange.

3. A high temperature high-chloride flue gas treatment device according to claim 1 or 2, characterized in that, The bottom end of the connecting flue is connected with the flue gas inlet of the absorption tower.

4. A high temperature high chlorine flue gas treatment device according to claim 3, characterized in that The bottom end of the absorption tower is provided with a pulse stirring device.

5. A high temperature high chlorine flue gas treatment device according to claim 1, characterized in that, The absorption tower is provided with a plurality of spray layers above the turbulence module.

6. A high temperature high chlorine flue gas treatment device according to claim 5, characterized in that Air flow distribution grids are arranged between the two topmost spray layers, and the air flow distribution grids are made of glass steel.

7. A high temperature high chlorine flue gas treatment device according to claim 5 or 6, characterised in that, The plurality of spray layers are connected with a circulating pump on one side of the absorption tower through a circulating pipe, and the circulating pump is made of engineering plastic.

8. A high temperature high chlorine flue gas treatment device according to claim 7, characterized in that A demister layer is arranged above the plurality of spray layers, and a roof type demister is used, and a liquid collecting pan is arranged below.

9. A high temperature high-chloride fume treatment device according to claim 3, characterized in that, The absorption tower is made of glass steel, and a reinforced corrosion-resistant layer is arranged at the inlet of the absorption tower.

10. A high temperature high chlorine flue gas treatment device according to claim 1, characterized in that, The cooling section is made of carbon steel and coated with 50mm acid-resistant castable, and the connecting flue is made of high-temperature glass steel.

Images