A rock wool melting furnace exhaust gas treatment system

Abstract

The utility model relates to a kind of rock wool melting furnace waste gas treatment systems, belong to waste gas treatment technical field.Mainly including main processing tower body, gas distributor, filler layer, catalytic module, first spraying assembly, second spraying assembly, online monitoring device and programmable logic controller.Main processing tower body is vertical cylindrical structure, inside is divided into preliminary absorption zone, catalytic conversion zone and depth oxidation absorption zone from bottom to top in turn.Preliminary absorption zone is installed gas distributor and filler layer, and is provided with first spraying assembly, catalytic conversion zone is installed honeycomb catalytic module, and depth oxidation absorption zone is provided with second spraying assembly.Online monitoring device is by sensor data acquisition and by programmable logic controller control metering pump.The system is by multistage processing unit, and the synchronous efficient removal of SO2 and NOx in waste gas is realized, effectively solve the problem that equipment is dispersed in traditional process, reagent waste and nitrogen oxides are not removed completely.

Description

Technical Field

[0001] This utility model belongs to the field of waste gas treatment technology, specifically relating to a waste gas treatment system for a rock wool melting furnace. Background Technology

[0002] In the production of rock wool, natural minerals such as basalt and diabase are used as the main raw materials. These are melted in a high-temperature furnace at 1400–1500℃ and then centrifuged or blown into fibers to produce inorganic thermal insulation materials. This process generates large amounts of SO2 and NO. x High-temperature exhaust gas containing dust and trace heavy metals, including SO2 and NO. x These are major pollutants. If not treated promptly and effectively, these gases can cause serious environmental pollution and harm human health. For example, SO2 can lead to acid rain, while NO... x It will participate in the formation of photochemical smog, further exacerbating the deterioration of air quality.

[0003] Currently, the common practice for treating exhaust gas from rock wool melting furnaces is to use a process of "cooling + bag filter dust collection + wet desulfurization". However, this process has several limitations in practical applications. Traditional wet desulfurization towers are mainly designed for SO2, and are less effective for NO (which is poorly soluble in water). x The removal efficiency of SO2 and NO (over 90% of the total) is relatively low, making it difficult to meet stringent emission standards. Furthermore, existing systems often use a fixed ratio of NaOH or lime slurry, which cannot dynamically adjust the dosage according to the waste gas load, easily leading to reagent waste or unstable treatment efficiency. Additionally, if denitrification is required, an additional SCR or SNCR system is usually needed, increasing investment costs and floor space. The complexity of operation and the susceptibility of the catalyst to deactivation by dust and alkaline substances also limit its widespread application. Therefore, a compact system capable of simultaneously and efficiently removing SO2 and NO is needed. x The waste gas treatment system that enables precise dosing of chemicals is of great significance for meeting the needs of the rock wool industry for green and low-carbon development. Utility Model Content

[0004] In order to overcome the problems in the background technology, this utility model provides a rock wool melting furnace exhaust gas treatment system to solve the problems of complex equipment structure, high operating cost and low nitrogen oxide removal efficiency caused by the separation of desulfurization and denitrification processes in the prior art.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: A rock wool melting furnace exhaust gas treatment system mainly includes a main treatment tower body. An exhaust gas inlet is provided at the bottom of the main treatment tower body, and a cyclone dust collector is installed in front of the exhaust gas inlet. The cyclone dust collector is connected to the main treatment tower body through a flange. A purified gas outlet is provided at the top of the main treatment tower body, and a sewage outlet is provided at the bottom. The sewage outlet is connected to a sedimentation tank through a circulating liquid return pipe. The interior of the main treatment tower body is divided into a preliminary absorption zone, a catalytic conversion zone, and a deep oxidation absorption zone from bottom to top. A gas distributor is installed in the preliminary absorption zone. The gas distributor consists of multiple radially arranged guide plates, which are fixed to the bottom of the main treatment tower by bolts. A packing layer is provided above the gas distributor. A first spray assembly is also provided in the preliminary absorption zone. The first spray assembly is connected to an alkaline solution storage tank and a metering pump through pipes. A honeycomb catalytic module is installed in the catalytic conversion zone. The catalytic module is fixed to the middle of the main treatment tower by a detachable bracket. A flow guide ring is provided at the bottom of the catalytic conversion zone, and the edge of the flow guide ring is in close contact with the inner wall of the main treatment tower. A buffer zone is formed between the flow guide ring and the bottom of the catalytic conversion zone, and the height of the buffer zone is 0.1 to 0.2 times the inner diameter of the tower. A collection tank is provided at the bottom of the catalytic module, which is located above the buffer zone. The surface of the collection tank has evenly opened circular holes, and a gas riser is welded above the circular holes. The top of the gas riser is provided with an umbrella cap. The bottom of the collection tank is connected to the sedimentation tank through a circulating liquid return pipe. A partition plate is provided between the catalytic conversion zone and the deep oxidation absorption zone, and the surface of the partition plate has evenly distributed small holes; a second spray assembly is provided in the deep oxidation absorption zone, and the second spray assembly is connected to the oxidant storage tank and the metering pump through a pipe; a distribution plate is installed below the second spray assembly, and the surface of the distribution plate has evenly distributed small holes. The system also includes an online monitoring device and a programmable logic controller (PLC). The online monitoring device includes two sets of sensors, which are respectively installed on the circulating liquid return pipelines of the preliminary absorption zone and the deep oxidation absorption zone. Each set of sensors consists of a probe and a signal line. The probe is inserted into the circulating liquid, and the signal line is connected to the PLC. The PLC receives the real-time data collected by the sensors and adjusts the start / stop and flow rate of the metering pump according to preset logic.

[0006] Furthermore, a transition section is provided between the preliminary absorption zone and the catalytic conversion zone. The inner wall of the transition section is equipped with spirally arranged guide vanes. The guide vanes are evenly distributed at a spiral angle of 15 degrees and welded to the inner wall of the main treatment tower 1 at intervals of 50 mm. The cross-section of the guide vanes is rectangular, with a width of 50 mm and a thickness of 3 mm.

[0007] Furthermore, the honeycomb structure of the catalytic module has a pore density of 200 mesh per square inch, and the inner wall of each pore is coated with a catalyst coating; a collection tank is provided at the bottom of the catalytic module, which is located above the buffer zone, and its surface is uniformly opened with circular holes and a gas riser is welded above the circular holes. The bottom of the collection tank is connected to the sedimentation tank through a circulating liquid return pipe.

[0008] Furthermore, the aperture of the small holes on the surface of the distribution plate is 1 to 2 mm; the aperture of the small holes on the surface of the isolation plate is 3 to 5 mm.

[0009] Furthermore, the top of the main processing tower is equipped with a two-stage demister. The demister is composed of multiple corrugated plates with a plate thickness of 0.8 mm, a corrugation spacing of 20 mm, and a corrugation depth of 40 mm. Each corrugated plate is connected by snap-fit.

[0010] Furthermore, the main processing tower body is welded from carbon steel, and the inner wall is lined with an acid and alkali resistant glass flake anti-corrosion coating; the outer wall of the main processing tower body is wrapped with an insulation layer, which is made of aluminum silicate fiber material and has a thickness of 50 mm.

[0011] The beneficial effects of this utility model are: This invention achieves simultaneous and efficient removal of SO2 and NOx from waste gas through a multi-stage treatment unit structure and dynamic control mechanism. The three-section functional zoning structure of the main treatment tower ensures a continuous and compact waste gas treatment process. The structural combination of the gas distributor and guide ring ensures uniform airflow distribution. The special construction of the honeycomb catalytic module provides a sufficient catalytic reaction interface. The combination of the dual spray assembly and the distribution plate enhances gas-liquid contact efficiency. The connection between the online monitoring device and the programmable logic controller enables precise control of reagent dosing. This system effectively solves the problems of dispersed equipment, reagent waste, and incomplete removal of nitrogen oxides in traditional processes, and features a compact structure, stable operation, and high treatment efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0013] Figure 2 This is a three-dimensional schematic diagram of the internal structure of this utility model.

[0014] Figure 3 This is a plan view of the internal structure of this utility model.

[0015] Figure 4 This is a three-dimensional structural diagram of the demister of this utility model.

[0016] Figure 5 A three-dimensional structural diagram of the gas distributor of this utility model.

[0017] Figure 6 This is a three-dimensional structural diagram of the collection trough of this utility model.

[0018] Figure 7 This is a three-dimensional structural diagram of the detachable bracket of this utility model.

[0019] Explanation of reference numerals in the attached drawings: 1. Main treatment tower body; 2. Exhaust gas inlet; 3. Purified gas outlet; 4. Gas distributor; 5. Guide vane; 6. Flow guide plate; 7. Catalytic module; 8. Detachable support; 9. First spray assembly; 10. Second spray assembly; 11. Distribution plate; 12. Online monitoring device; 13. Metering pump; 14. Isolation plate; 15. Flow guide ring; 16. Collection tank; 17. Demister; 18. Sewage outlet; 19. Rise pipe. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0021] This utility model discloses a waste gas treatment system for a rock wool melting furnace. The system mainly includes a main treatment tower 1, a gas distributor 4, a packing layer, a catalytic module 7, a first spray assembly 9, a second spray assembly 10, an online monitoring device 12, and a programmable logic controller.

[0022] Specifically, the main treatment tower 1 is a vertical cylindrical structure with a total height of approximately 15 meters and an outer diameter of approximately 3 meters. The main body of the tower 1 is integrally formed from Q235 carbon steel through welding. Its inner wall is lined with a 5 mm thick acid and alkali resistant glass flake anti-corrosion coating, which possesses excellent chemical stability and wear resistance, effectively resisting the erosion of acidic substances in the exhaust gas. The bottom of the main treatment tower 1 is equipped with an exhaust gas inlet 2 and a drain outlet 18, with the drain outlet 18 connected to a sedimentation tank via a circulating liquid return pipe. The exhaust gas inlet 2 is a horizontally extending circular pipe with an inner diameter of approximately 500 mm, connected to an external exhaust gas pipe via a flange connection. The top center of the main treatment tower 1 is equipped with a purified gas outlet 3, which is a vertically extending circular pipe with an inner diameter approximately the same as that of the exhaust gas inlet 2 (approximately 500 mm), also connected to an external purified gas emission chimney via a flange connection. The internal space of the main processing tower 1 is divided into three functional areas from bottom to top: the preliminary absorption area, the catalytic conversion area, and the deep oxidation absorption area. These areas are physically separated and functionally defined inside the tower by structural components.

[0023] A cyclone dust collector is installed in front of the exhaust gas inlet 2, before the exhaust gas enters the main treatment tower 1. The main shell of the cyclone dust collector is made of 304 stainless steel through welding. The cyclone dust collector has a cylindrical and conical structure, with a dust collection hopper at the bottom of the conical shape for easy collection and discharge of dust. The outlet of the cyclone dust collector is connected to the exhaust gas inlet 2 of the main treatment tower 1 via a standard flat flange with a diameter of 500 mm. This flange connection is secured evenly with twelve M16 bolts, and a 3 mm thick PTFE gasket is sandwiched between the two flange connection surfaces to ensure the sealing integrity of the connection in high-temperature and corrosive gas environments. The inlet pipe of the cyclone dust collector is designed to enter tangentially, causing the exhaust gas to form a high-speed rotating airflow inside. Centrifugal force separates most of the larger dust particles in the exhaust gas and causes them to settle into the dust collection hopper.

[0024] The preliminary absorption zone is located at the bottom of the main treatment tower 1, immediately above the exhaust gas inlet 2. A gas distributor 4 is installed in this zone. The gas distributor 4 consists of multiple radially arranged guide plates 6. Specifically, the guide plates 6 are flat plate structures cut from 316L stainless steel. The surface of the guide plates 6 is uniformly coated with a 0.2 mm thick PTFE corrosion-resistant coating, which further enhances the corrosion resistance of the guide plates 6 in acidic solutions and exhaust gases. The multiple guide plates 6 are arranged in a grid structure using several M10 stainless steel bolts in a cross-shaped pattern, and are fixed by pre-embedded nuts welded to the inner wall of the tower bottom. This structure allows the exhaust gas entering from the exhaust gas inlet 2 to be evenly dispersed during its ascent, avoiding airflow short-circuiting and excessively high local flow velocities, and providing a uniform gas-liquid contact interface for the subsequent packing layer.

[0025] Above the gas distributor 4, a stainless steel packing support grid is used for support, and a packing layer is provided. The packing layer consists of a large number of polypropylene (PP) Pall ring packings stacked to a height of approximately 1.5 to 2 meters. The nominal diameter of the Pall ring packing is 50 mm, and its unique open ring structure increases the gas-liquid contact area. The packing support grid is made of several 304 stainless steel round bars with a diameter of 20 mm, welded together in a grid pattern. The grid opening rate reaches over 95% to ensure smooth flow of gas and liquid while firmly supporting the packing layer. The edges of the grid are tightly connected to the inner wall of the main treatment tower 1 by welding.

[0026] The preliminary absorption zone is also equipped with a first spray assembly 9. The first spray assembly 9 is connected to an external alkaline solution storage tank via a DN80 diameter PP pipe. The alkaline solution storage tank is a 10 cubic meter volume PE vertical tank with good alkali resistance. A plunger-type metering pump 13 is installed in series on the connecting pipe. This metering pump 13 is electrically connected to a programmable logic controller via a cable, with a rated flow rate of 0 to 500 liters per hour and a maximum head of 20 meters, enabling precise control of the reagent dosage. Within the preliminary absorption zone of the main treatment tower 1, the first spray assembly 9 has multiple sets of fully conical nozzles evenly arranged circumferentially along the interior of the tower. These nozzles are mounted in a ring array on horizontally arranged 150 mm diameter UPVC spray pipes. The spray pipes are fixed to the inner wall of the main treatment tower 1 by 304 stainless steel brackets and connected to the external DN80 diameter PP liquid supply pipe via a standard flange. Each nozzle has a 90-degree spray angle and a flow rate of 5 liters per minute at a pressure of 0.2 MPa. The main body of the nozzle is made of high-performance silicon carbide ceramic, which is characterized by excellent wear resistance and corrosion resistance. The sprayed alkaline solution is in the form of fine droplets, which can carry out a highly efficient gas-liquid contact reaction with the acidic gas (SO2) in the rising exhaust gas.

[0027] A transition section is provided between the preliminary absorption zone and the catalytic conversion zone. The vertical height of the transition section is approximately 0.5 to 0.8 meters. Helically arranged guide vanes 5 are installed on the inner wall of the main treatment tower 1. These guide vanes 5 are made of 304 stainless steel, with a rectangular cross-section, a width of 50 mm, and a thickness of 3 mm. These guide vanes 5 are evenly distributed at a helical angle of 15 degrees and welded to the inner wall of the main treatment tower 1 at 50 mm intervals, forming a torsional airflow channel with a certain turbulence effect. This aims to further homogenize the waste gas flow velocity and create a more stable flow field for entry into the catalytic conversion zone.

[0028] The catalytic conversion zone is the middle area of ​​the main processing tower 1, located above the preliminary absorption zone. At the bottom of the catalytic conversion zone, immediately above the transition section, a guide ring 15 is installed. The guide ring 15 is made of 304 stainless steel welded from rolled plates; it is annular, 100 mm wide, and 10 mm thick. The edge of the guide ring 15 is fully welded to the inner wall of the main processing tower 1. Its inner diameter is smaller than the outer diameter of the catalytic module 7, forming a circular airflow channel at the center of the ring. A buffer zone is formed between the guide ring 15 and the bottom of the catalytic conversion zone. The height of the buffer zone is 0.1 to 0.2 times the inner diameter of the tower (e.g., 400-500 mm), providing a buffer or diffusion space for the airflow. After leaving the guide ring 15, the airflow can slow down and streamline within this space, thus more smoothly and evenly covering the entire bottom cross-section of the catalytic module. The guide ring 15 effectively disrupts the rising airflow along the tower wall through its physical obstruction, forcing it to converge towards the center and avoiding problems such as "wall flow" and "short circuit". After passing through the airflow channel in the center of the guide ring 15, the airflow redisperses at the bottom cross-section of the catalytic module 7, resulting in a more uniform distribution upon entering the catalytic module 7. This also prevents excessively high flow velocities in localized areas of the catalytic module 7, thereby reducing catalyst wear and pulverization caused by high-velocity scouring and extending the catalyst's lifespan.

[0029] A honeycomb-shaped catalytic module 7 is installed within the catalytic conversion zone. The catalytic module 7 is constructed from a cordierite substrate, which possesses excellent high-temperature resistance and a low coefficient of thermal expansion, making it less prone to cracking under temperature changes. A composite oxide catalyst is uniformly loaded onto the surface of the cordierite substrate. Specifically, the cordierite substrate is immersed in a solution containing Mn(NO3)2, Ce(NO3)3, and TiO2 sol (molar ratio Mn:Ce=3:1), allowed to stand for 30 minutes, removed, dried at 110°C for 2 hours, and then calcined at 450°C for 4 hours to form a uniform coating with a thickness of 0.1–0.2 mm. This catalyst exhibits excellent catalytic oxidation activity for nitrogen oxides (NOx) in waste gas, with an oxidation efficiency exceeding 85%. The honeycomb structure of the catalytic module 7 has a pore density of 200 mesh per square inch. The inner wall of each channel is uniformly coated with a catalyst coating with a thickness of 0.1 mm to 0.2 mm. This high specific surface area honeycomb structure provides a large gas-liquid contact interface and catalytic reaction sites. The catalytic module 7 is fixed to the central area of ​​the main processing tower 1 by a detachable bracket 8. The detachable bracket 8 is made of 304 stainless steel and has a cross-shaped or grid-shaped grid structure, which fully considers the self-weight of the catalytic module 7 and the impact force of airflow. The four ends (cross-shaped) or multiple ends (grid-shaped) of the detachable bracket 8 are connected to the inner wall of the main processing tower 1 by bolted flanges. This connection method allows the catalytic module 7 to be easily disassembled when maintenance or replacement is required, ensuring its stability and ease of maintenance.

[0030] The bottom of the catalytic module 7 is equipped with a collection tank 16. The collection tank 16 has a disc-shaped structure, located above the buffer zone, and is made of 304 stainless steel through stamping and welding processes. Its central area is recessed to form a collection pit, while the edges are raised and fully welded to the inner wall of the main treatment tower 1 to ensure no liquid leakage. The collection tank 16 has evenly spaced circular holes, and a riser pipe 19 is welded above each hole, allowing gas to smoothly enter the catalytic module 7 from the riser pipe 19. A cap is provided at the top of the riser pipe 19 to prevent waste liquid from entering it. A DN100 diameter circular hole is located at the center of the bottom of the collection tank 16, which is connected to an external sedimentation tank via a DN100 diameter PP circulating liquid return pipe. The circulating liquid generated in the deep oxidation absorption zone is intercepted by the disc surface of the collection tank 16 and cannot enter the gas flow channel due to the obstruction of the riser pipe 19. Ultimately, it collects in the central collection pit under gravity and is discharged to the sedimentation tank through the circulating liquid return pipe.

[0031] A partition plate 14 is installed between the catalytic conversion zone and the deep oxidation absorption zone. The partition plate 14 is made of 5 mm thick 304 stainless steel flat plate through laser cutting and stamping processes. The surface of the partition plate 14 has hundreds of evenly distributed circular holes, each with a diameter of 3 mm to 5 mm. The partition plate 14 is fixed to the inner wall of the main treatment tower 1 by welding, with its plane perpendicular to the tower axis. This partition plate 14 allows the spray liquid from the upper deep oxidation absorption zone to flow downwards evenly, while effectively preventing some of the upper liquid from flowing directly and rapidly to the lower catalytic conversion zone, preventing localized liquid accumulation at the top of the catalytic module 7, which would affect the uniformity of the airflow and the normal function of the catalyst.

[0032] The deep oxidation absorption zone is located in the upper part of the main treatment tower 1, above the isolation plate 14. A second spray assembly 10 is installed in this zone. The second spray assembly 10 is connected to an external oxidant storage tank via a DN80 PVDF (polyvinylidene fluoride) pipe. The oxidant storage tank is a 5-cubic-meter vertical PE tank, whose material has good corrosion resistance to oxidants. A plunger-type metering pump 13 is also installed in series on the connecting pipe. This metering pump 13 is electrically connected to a programmable logic controller via a cable, with a rated flow rate of 0 to 300 liters per hour and a maximum head of 20 meters, enabling precise control of the oxidant dosage. Within the deep oxidation absorption zone of the main treatment tower 1, the second spray assembly 10 has multiple sets of spiral nozzles evenly arranged circumferentially along the interior of the tower. These nozzles are installed in a ring array on horizontally arranged PVDF spray pipes with a diameter of 150 mm. The spray pipes are fixed to the inner wall of the main treatment tower 1 by 316L stainless steel brackets and connected to the external DN80 PVDF liquid supply pipe via standard flanges. Each nozzle has a spray angle of 120 degrees, and at a pressure of 0.2 MPa, the spray flow rate of a single nozzle is 3 liters per minute. The main body of the nozzle is made of PVDF, which is characterized by excellent resistance to strong oxidants and high temperature resistance. The sprayed oxidant solution is in the form of fine droplets, which undergo a highly efficient gas-liquid contact oxidation absorption reaction with nitrogen oxides (NOx) in the rising exhaust gas.

[0033] A distribution plate 11 is installed below the second spray assembly 10. The distribution plate 11 is made of PP material, is a circular flat plate, and has a thickness of 8 mm. The surface of the distribution plate 11 has up to a thousand evenly distributed circular holes, each with a diameter of 1 mm to 2 mm. The distribution plate 11 is bolted to the inner wall of the main treatment tower 1 by several lugs located at its edge. The distribution plate 11 allows the droplets sprayed from the second spray assembly 10 to be evenly distributed downwards, forming a continuous liquid film, further increasing the gas-liquid contact surface area, thereby improving the absorption efficiency.

[0034] The online monitoring device 12 includes two independent sensor units. The two sensor units are respectively installed on the circulating liquid return pipes of the preliminary absorption zone and the deep oxidation absorption zone. Each sensor unit consists of a probe and a signal line. The probe is encapsulated in corrosion-resistant PTFE (polytetrafluoroethylene) material, and its measuring part (e.g., a pH electrode or an ORP electrode) is inserted into a DN100 diameter PVC circulating liquid return pipe and fixed by a DN100 flange connection, ensuring full contact and sealing between the probe and the circulating liquid. The signal line is a multi-core shielded cable, with one end connected to the probe via a waterproof connector, and the other end connected to an external programmable logic controller via an industrial-grade terminal block.

[0035] At the top of the main treatment tower 1, below the purified gas outlet 3, a two-stage demister 17 is installed. The demister 17 consists of multiple layers of corrugated plates, each layer connected by snap-fit ​​mechanisms to form a complex flow channel. The corrugated plates are made of 316L stainless steel, with a thickness of 0.8 mm, a corrugation spacing of 20 mm, and a corrugation depth of 40 mm. The demister 17 is installed inside the main treatment tower 1 via an annular support plate. The structure of the demister 17 allows for the effective removal of entrained fine droplets from the rising gas through inertial collision, interception, and diffusion, preventing secondary pollution caused by droplets being discharged with the purified gas.

[0036] The outer wall of the main processing tower 1 is covered with a 50 mm thick insulation layer made of aluminum silicate fiber material, which is fixed and protected by an external aluminum sheet pressing plate. This insulation layer can effectively reduce heat loss inside the tower and maintain a suitable reaction temperature inside the tower, especially playing an important role in maintaining the temperature of the catalytic reaction in the catalytic conversion zone.

[0037] The programmable logic controller (PLC) is installed in a separate industrial-grade control cabinet with an IP65 protection rating. The PLC receives real-time data signals (e.g., pH or ORP values) from sensors in the two sets of online monitoring devices 12 via a multi-core shielded cable. The PLC has a pre-set precise logic control program and a PID (Proportional-Integral-Derivative) control algorithm. The PLC is electrically connected to the metering pump 13 connected to the first spray assembly 9 in the preliminary absorption zone and the metering pump 13 connected to the second spray assembly 10 in the deep oxidation absorption zone via one-to-one digital and analog output signal lines. Based on the received real-time data signals, the PLC controls the start / stop status and pumping flow rate of the corresponding metering pump 13 by adjusting the output voltage or current signals (e.g., by adjusting the stroke length or stroke frequency of the metering pump), thereby achieving precise and dynamic adjustment of the alkaline solution and oxidant dosage. The programmable logic controller also has the function of communicating with a host computer (such as a SCADA system or DCS system). Its communication interface is a standard RS485 interface, which supports the Modbus RTU protocol to realize remote monitoring and data management.

[0038] The specific working process of the entire device is as follows: The high-temperature exhaust gas from the rock wool melting furnace first enters the cyclone dust collector. The exhaust gas enters the cylindrical section of the cyclone dust collector tangentially, creating a high-speed rotating airflow inside. Due to centrifugal force, larger dust particles in the exhaust gas are thrown against the collector wall and lose kinetic energy after colliding with it, settling down the conical bottom into the dust collection hopper. After preliminary dust removal, the exhaust gas exits from the outlet at the top of the cyclone dust collector and enters the exhaust gas inlet 2 at the bottom of the main treatment tower 1 through a flange-connected pipe.

[0039] After entering the preliminary absorption zone of the main treatment tower 1, the waste gas first passes through the gas distributor 4. Multiple radially arranged guide plates 6 of the gas distributor 4 evenly disperse the waste gas, forming a stable upward airflow. The evenly distributed waste gas rises through the packing layer. Simultaneously, the first spray assembly 9 sprays an alkaline solution (such as sodium hydroxide solution) downwards through its annular array of fully conical nozzles. The alkaline solution, in the form of fine droplets, contacts the rising waste gas counter-currently, forming a liquid film on the surface of the Pall ring packing in the packing layer, greatly increasing the gas-liquid contact area. Sulfur dioxide (SO2) in the waste gas undergoes a neutralization reaction with the alkaline solution, generating sulfite or sulfate, thus achieving preliminary desulfurization. The recycled liquid after the reaction is discharged to the sedimentation tank through a return pipeline.

[0040] The exhaust gas, after preliminary absorption treatment, continues to rise and passes through the transition section. The spirally arranged guide vanes 5 on the inner wall of the transition section create a rotating, upward airflow, further homogenizing the flow velocity before entering the catalytic conversion zone. At the bottom of the catalytic conversion zone, the guide ring 15 concentrates and guides the exhaust gas through a circular airflow channel formed at its center, entering a buffer zone for buffering and diffusion. Then, the gas smoothly enters the catalytic module 7 from the riser pipe 19, ensuring uniform airflow distribution while preventing direct impact on the catalytic module 7 above.

[0041] The exhaust gas passes uniformly through the micropores of the honeycomb catalytic module 7. On the inner wall of the pores of the catalytic module 7, the supported composite oxide catalyst catalytically oxidizes nitric oxide (NO) in the exhaust gas at a suitable temperature, converting it into more easily absorbed nitrogen dioxide (NO2). Simultaneously, some unreacted SO2 may also be further oxidized in this area. The waste liquid generated during the catalytic reaction is collected in the collection tank 16. Due to the obstruction of the riser pipe 19, the waste liquid cannot enter the gas flow channel and ultimately collects in the central collection pit under gravity, and is discharged to the sedimentation tank through the circulating liquid return pipe.

[0042] The catalytically converted waste gas enters the deep oxidation absorption zone through uniformly spaced small holes on the isolation plate 14. The isolation plate 14 effectively prevents the upper liquid from flowing directly and rapidly downwards, maintaining the relative dryness of the catalytic conversion zone. In the deep oxidation absorption zone, the second spray assembly 10 sprays an oxidant solution (such as sodium hypochlorite solution) downwards through its spiral nozzles. The oxidant solution comes into countercurrent contact with the rising waste gas, oxidizing and absorbing the catalytically converted nitrogen oxides (mainly NO2) to generate nitrates. Simultaneously, the distribution plate 11 ensures that the spray liquid is evenly distributed to form a continuous liquid film, further enhancing the gas-liquid contact efficiency and ensuring that residual SO2 and NOx are deeply removed.

[0043] The treated exhaust gas continues to rise and passes through a two-stage demister 17. In the intricate flow channels of the demister 17, liquid droplets entrained in the exhaust gas are effectively removed through inertial collision, interception, and diffusion. The dry and clean purified gas is finally discharged from the purified gas outlet 3 at the top of the main treatment tower 1 and enters the external chimney for emission in compliance with standards.

[0044] Throughout the treatment process, online monitoring devices 12 installed on the circulating liquid return pipelines in the preliminary absorption zone and the deep oxidation absorption zone monitor parameters such as pH and ORP in real time. The monitoring data is transmitted to the programmable logic controller (PLC) via signal lines. Based on preset control logic and PID algorithms, the PLC dynamically adjusts the dosage of the two metering pumps 13, precisely controlling the dosage ratio of alkaline solution and oxidant to ensure stable treatment results and optimal reagent consumption. Through the multi-stage treatment unit structure and intelligent control mechanism, the entire device achieves efficient and synergistic removal of SO2 and NOx from the rock wool melting furnace exhaust gas.

[0045] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A waste gas treatment system for a rock wool melting furnace, characterized in that: The main treatment tower (1) includes a main treatment tower body (1), a waste gas inlet (2) is provided at the bottom of the main treatment tower body (1), a cyclone dust collector is installed in front of the waste gas inlet (2), and the cyclone dust collector is connected to the main treatment tower body (1) through a flange; a purified gas outlet (3) is provided at the top of the main treatment tower body (1), and a sewage outlet (18) is provided at the bottom, and the sewage outlet (18) is connected to the sedimentation tank through a circulating liquid return pipe; the interior of the main treatment tower body (1) is divided into a preliminary absorption zone, a catalytic conversion zone and a deep oxidation absorption zone from bottom to top. A gas distributor (4) is installed in the preliminary absorption zone. The gas distributor (4) consists of multiple radially arranged guide plates (6). The guide plates (6) are fixed to the bottom of the main treatment tower (1) by bolts. A packing layer is provided above the gas distributor (4). A first spray assembly (9) is also provided in the preliminary absorption zone. The first spray assembly (9) is connected to an alkaline solution storage tank and a metering pump (13) through a pipeline. A honeycomb catalytic module (7) is installed in the catalytic conversion zone. The catalytic module (7) is fixed to the middle of the main treatment tower (1) by a detachable bracket (8). A guide ring (15) is provided at the bottom of the catalytic conversion zone. The edge of the guide ring (15) is tightly fitted to the inner wall of the main treatment tower (1). A buffer zone is formed between the guide ring (15) and the bottom of the catalytic conversion zone. The height of the buffer zone is 0.1 to 0.2 times the inner diameter of the tower. A collection tank (16) is provided at the bottom of the catalytic module (7). The collection tank (16) is located above the buffer zone. Circular holes are evenly opened on its surface, and a riser pipe (19) is welded above the circular holes. A cap is provided at the top of the riser pipe (19). The bottom of the collection tank (16) is connected to the sedimentation tank through a circulating liquid return pipe. A partition plate (14) is provided between the catalytic conversion zone and the deep oxidation absorption zone, and the partition plate (14) has uniformly distributed small holes on its surface; a second spray assembly (10) is provided in the deep oxidation absorption zone, and the second spray assembly (10) is connected to the oxidant storage tank and the metering pump (13) through a pipe; a distribution plate (11) is installed below the second spray assembly (10), and the distribution plate (11) has uniformly distributed small holes on its surface; The system also includes an online monitoring device (12) and a programmable logic controller. The online monitoring device (12) includes two sets of sensors, which are installed on the circulating liquid return pipes of the preliminary absorption zone and the deep oxidation absorption zone, respectively. Each set of sensors consists of a probe and a signal line. The probe is inserted into the circulating liquid, and the signal line is connected to the programmable logic controller. The programmable logic controller receives the real-time data collected by the sensors and adjusts the start and stop of the metering pump (13) and the flow rate according to the preset logic.

2. The rock wool melting furnace exhaust gas treatment system according to claim 1, characterized in that: A transition section is provided between the preliminary absorption zone and the catalytic conversion zone. The inner wall of the transition section is equipped with spirally arranged guide vanes (5). The guide vanes (5) are evenly distributed at a spiral angle of 15 degrees and welded to the inner wall of the main treatment tower (1) at intervals of 50 mm. The cross-section of the guide vanes (5) is rectangular, with a width of 50 mm and a thickness of 3 mm.

3. The rock wool melting furnace exhaust gas treatment system according to claim 1 or 2, characterized in that: The catalytic module (7) has a honeycomb structure with a pore density of 200 meshes per square inch, and the inner wall of each pore is coated with a catalyst coating.

4. The rock wool melting furnace exhaust gas treatment system according to claim 1 or 2, characterized in that: The aperture of the small holes on the surface of the distribution plate (11) is 1 to 2 mm; the aperture of the small holes on the surface of the isolation plate (14) is 3 to 5 mm.

5. The rock wool melting furnace exhaust gas treatment system according to claim 1 or 2, characterized in that: The top of the main processing tower (1) is equipped with a two-stage demister (17). The demister (17) is composed of multiple corrugated plates with a plate thickness of 0.8 mm, a corrugation spacing of 20 mm, and a corrugation depth of 40 mm. Each corrugated plate is connected by a snap fastener.

6. The rock wool melting furnace exhaust gas treatment system according to claim 1, characterized in that: The main processing tower body (1) is made of carbon steel welded together, and the inner wall is lined with an acid and alkali resistant glass flake anti-corrosion coating; the outer wall of the main processing tower body (1) is wrapped with a heat insulation layer, which is made of aluminum silicate fiber material and has a thickness of 50 mm.

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