A setting machine exhaust gas treatment device

Abstract

This invention discloses a waste gas treatment device for a stenter, relating to the textile printing and dyeing field. The key technical features are: a double-cone duct, a central pipe, a two-stage cyclone purifier, a three-stage cyclone purifier, and an exhaust fan. The double-cone duct and the central pipe are respectively equipped with a second spray device and a third spray device. The two-stage cyclone purifier includes a two-stage purification tank, a two-stage inlet pipe, and a two-stage outlet pipe; the three-stage cyclone purifier includes a three-stage purification tank, a three-stage inlet pipe, and a three-stage outlet pipe. This invention, through the swirling air collection of the double-cone duct, the multi-stage wet spray separation of the central pipe and each stage of the cyclone purifier, and the synergistic effect of the three-stage overflow water circulation system, can stably achieve compliant waste gas emissions. Simultaneously, it enables simultaneous spraying and purification throughout the entire process, eliminating the need for manual shutdown for cleaning. It also features an initial fire suppression and cooling function, reducing overall costs such as electricity, consumables, labor, and downtime losses.

Description

Technical Field

[0001] This invention relates to the field of textile printing and dyeing, and more specifically, to a waste gas treatment device for a setting machine. Background Technology

[0002] Currently, the mainstream equipment for treating exhaust gas from stenters on the market is mainly divided into two categories: electrostatic purification equipment and filter cartridge purification equipment. Both types of equipment have persistent industry-specific drawbacks in long-term operation.

[0003] Electrostatic purification equipment: It is equipped with a high-voltage power supply system, resulting in high overall energy consumption; the inside of the electrode plates is prone to the accumulation of oil and lint, requiring regular shutdown for manual cleaning, making daily maintenance difficult and repair costs high after parts wear out; the accumulation of oil on the electrode plates can easily generate high-voltage arcing, causing fires in the equipment and pipelines, posing significant safety risks.

[0004] Filtration-type purification equipment: The exhaust fan has a high power configuration and high operating energy consumption; the internal filter element is filled with filter elements, which are prone to clogging due to long-term interception of oil and fibers, requiring regular shutdowns for cleaning; the filter element must be replaced as a whole after reaching the end of its service life, and the replaced waste filter element is hazardous waste with high disposal costs; the filter element itself is made of flammable material, which can easily ignite and cause fire when exposed to sparks inside the pipe, posing a significant safety hazard.

[0005] In summary, existing electrostatic and filtration equipment generally suffer from a series of industry pain points, such as being prone to fire, requiring manual shutdown for cleaning, high energy consumption, difficult maintenance, high repair costs, and generating hazardous waste consumables, which seriously affect the safe and continuous stable production of printing and dyeing enterprises.

[0006] Therefore, a new solution is needed to address this problem. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a stenter exhaust gas treatment device.

[0008] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a stenter exhaust gas treatment device, comprising a double-cone duct pipe, a central pipe, a two-stage cyclone purifier, a three-stage cyclone purifier, and an exhaust fan, wherein the double-cone duct pipe is connected to the stenter through an exhaust branch pipe, and a first spray device is provided in the exhaust branch pipe; the diameter of the double-cone duct pipe is smaller as it approaches both ends; the central pipe is located in the middle of the double-cone duct pipe and is connected to the double-cone duct pipe; a second spray device and a third spray device are respectively provided in the double-cone duct pipe and the central pipe. The secondary cyclone purifier includes a secondary purification tank, a secondary air inlet pipe, and a secondary air outlet pipe. The secondary purification tank includes a vortex-shaped upper tank and a cone-shaped lower tank. The secondary purification tank is connected to a central pipe through the secondary air inlet pipe, which is tangent to the outer peripheral wall of the upper tank. The secondary air outlet pipe is located at the center of the top surface of the upper tank, and one end of the secondary air outlet pipe inside the secondary purification tank extends to the lower tank. The three-stage cyclone purifier includes a three-stage purification tank, a three-stage air inlet pipe, and a three-stage air outlet pipe. A partition plate is installed inside the three-stage purification tank, which divides the space inside the three-stage purification tank into an upper cavity and a lower cavity. The lower cavity includes a vortex cavity and a conical cavity. The vortex cavity is located above the conical cavity. A connecting pipe is installed at the center of the partition plate, and the lower end of the connecting pipe extends into the conical cavity. The three-stage air inlet pipe is connected to the vortex cavity and is tangent to the outer wall of the vortex cavity. A flow-blocking plate parallel to the partition plate is installed inside the upper cavity. The three-stage air outlet pipe is located at the center of the top surface of the three-stage purification tank and is connected to the upper cavity. One end of the exhaust fan is connected to the third-stage exhaust pipe, and the other end of the exhaust fan is connected to the smoke exhaust pipe. The second-stage and third-stage air inlet pipes are respectively equipped with a second-stage mixed-flow spray pipe and a third-stage mixed-flow spray pipe. The lower ends of the central pipe, the second-stage purification tank and the third-stage purification tank are all provided with liquid outlets.

[0009] The present invention is further configured such that: the air duct branch pipe includes a vertical section and an inclined section, the vertical section is connected to the shaping machine, the inclined section is inclined toward the double-cone air duct pipe and the included angle between the vertical section and the inclined section is less than 90 degrees, the first spraying device is disposed at the end of the inclined section away from the double-cone air duct pipe and the spraying direction of the first spraying device is disposed toward the double-cone air duct pipe.

[0010] The invention is further configured such that: a cleaning window is provided at the connection between the vertical section and the inclined section, and a sealing plate for closing the cleaning window is provided on the air duct branch pipe.

[0011] The present invention is further configured such that an emergency vent is provided at the top of the central tube.

[0012] The present invention is further configured such that: the first spray device, the second spray device and the third spray device are all supplied with water by the first overflow pool, the secondary mixed flow spray pipe is supplied with water by the second overflow pool, the tertiary mixed flow spray pipe is supplied with water by the third overflow pool, the liquid overflowing from the third overflow pool flows into the second overflow pool, and the liquid overflowing from the second overflow pool flows into the first overflow pool; The outlets of the central pipe, the secondary purification tank, and the tertiary purification tank are respectively connected to an oil-water separation circulating water processor, a secondary oil-water separation device, and a tertiary oil-water separation device. The liquid separated by the secondary oil-water separation device flows into the first overflow pool, and the liquid separated by the tertiary oil-water separation device flows into the second overflow pool. The third overflow pool is supplied with tap water.

[0013] The present invention is further configured to include a detection platform, wherein the detection platform is located near the outlet of the exhaust pipe, and a detection ladder is connected to the detection platform.

[0014] The present invention is further configured such that: the double-cone air duct, the central duct, the secondary cyclone purifier, the tertiary cyclone purifier and the exhaust fan together constitute a waste gas treatment unit, and there are multiple waste gas treatment units. The air outlet of the exhaust fan of each waste gas treatment unit is connected to the same main air duct, and the main air duct is then connected to the smoke exhaust pipe. A maintenance platform is fixedly installed on the outer wall of the main air duct.

[0015] In summary, the present invention has the following beneficial effects: The present invention provides a stenter exhaust gas treatment device, which achieves stable and compliant emission of stenter exhaust gas without relying on electrostatic adsorption and filtration interception technology through the swirl gas collection of the double cone air duct, the multi-stage wet spray separation of the central tube and various cyclone purifiers, and the synergistic effect of the three-stage overflow water circulation system.

[0016] At the same time, the present invention has the following advantages over the prior art: Firstly, it reduces overall operating costs. This invention eliminates the need for a high-power electrostatic generator unit and regular purchase and replacement of filter cartridges, thus reducing long-term operating expenses in terms of both electricity and consumables. At the same time, the exhaust fan is located at the end of the purification process, drawing in low-temperature clean gas that has been cooled and purified. The fan blades are less prone to oil accumulation, and the fan operates stably with a low failure rate, further reducing maintenance costs and downtime losses.

[0017] Secondly, it solves the problem of difficult operation and maintenance. The dual-cone duct and each level of purification unit are continuously sprayed and washed with water throughout the entire waste gas treatment process. Oil and lint are discharged from the outlet in real time with the water flow. Stubborn scale cannot form on the inner wall of the pipes and equipment. There is no need to stop the machine for manual cleaning periodically. This reduces the heavy work of frequently disassembling and cleaning electrode plates and replacing filter elements required by traditional equipment, and reduces the workload of operation and maintenance.

[0018] Third, it reduces the risk of fire at the source by having an initial fire extinguishing function. This invention does not have a static high-voltage ignition source, nor does it have the risk of spontaneous combustion of oil residue from flammable filter elements; the system operates in a wet water mist environment throughout, and all spray units work continuously. Once initial sparks appear in the drying chamber and enter the pipeline with the exhaust gas, the multi-stage spray water mist can immediately extinguish the sparks and cool the room, preventing the fire from spreading and reducing the probability of fire accidents in the setting machine.

[0019] Fourth, it saves water resources and reduces waste liquid discharge. Through a three-stage overflow water supply and oil-water separation and recycling design, the cleanest water is used for the final spray, and the more turbid water is used for the pre-wash. Only a small amount of tap water needs to be added to maintain the long-term stable operation of the system. The separated waste oil can be recycled and reused, reducing water costs and waste liquid disposal costs.

[0020] In summary, this invention specifically addresses three major industry pain points in existing electrostatic and filtration-type stenter exhaust gas treatment equipment: high operating costs, difficult operation and maintenance, and significant fire hazards. It has energy-saving and environmental protection benefits and high industrial application value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the two-stage cyclone purifier and the three-stage cyclone purifier in this invention; Figure 3 This is a cross-sectional view of the exhaust branch pipe in this invention; Figure 4 This is a schematic diagram of the structure of the first overflow pool, the second overflow pool, and the third overflow pool in this invention; Figure 5 This is a schematic diagram of the three-stage cyclone purifier in this invention.

[0022] In the diagram: 1. Double-cone duct; 2. Central duct; 3. Secondary cyclone purifier; 4. Tertiary cyclone purifier; 5. Exhaust fan; 6. First spray device; 7. Secondary purification tank; 8. Secondary air inlet pipe; 9. Secondary air outlet pipe; 10. Tertiary purification tank; 11. Tertiary air inlet pipe; 12. Tertiary air outlet pipe; 13. Divider plate; 14. Connecting pipe; 15. Cut-off plate; 16. Vertical section; 17. Inclined section; 18. Sealing plate; 19. Emergency vent; 20. First overflow pool; 21. Second overflow pool; 22. Third overflow pool; 23. Secondary oil-water separator; 24. Tertiary oil-water separator; 25. Testing platform; 26. Testing ladder; 27. Main duct; 28. Maintenance platform; 29. ​​Exhaust branch pipe; 30. Smoke exhaust pipe. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] A stenter exhaust gas treatment device, such as Figure 1 As shown, it includes a double-cone duct 1, a central duct 2, a two-stage cyclone purifier 3, a three-stage cyclone purifier 4, and an exhaust fan 5 for providing gas flow power. Among them, the double-cone duct 1 serves as a transverse main gas collection duct, which is connected to the exhaust ports of each section of the drying oven of the setting machine through the exhaust branch duct 29, and collects the high-temperature exhaust gas containing oil fumes and lint. The entire device employs a combination of wet spraying and cyclone separation, eliminating the need for high-power electrostatic electrodes and frequently replaced filter cartridges. This achieves a simultaneous operation mode of "purification during spraying and spraying during purification." The pipes and the inner walls of the purification units are continuously flushed by water, and oil and lint are discharged in real time without the need for manual cleaning during shutdown. At the same time, the wet water mist environment throughout the process enables the device to automatically extinguish and cool down in the event of an initial fire, effectively preventing the spread of fire along the pipes. After initial cyclone conveying and spraying washing in the double-cone duct 1, the exhaust gas enters the central pipe 2 for primary coarse purification. Subsequently, it is sequentially sent to the secondary cyclone purifier 3 and the tertiary cyclone purifier 4 connected in series for fine treatment. Finally, the purified gas is discharged into the atmosphere through the exhaust pipe 30.

[0025] like Figure 1 and Figure 3 As shown, the first stage is the waste gas collection and pretreatment stage. The double-cone duct 1 is connected to the stenter via an exhaust branch pipe 29. This exhaust branch pipe 29 specifically includes a vertical section 16 connected to the stenter oven and an inclined section 17 inclined towards the double-cone duct 1, with the angle between the vertical section 16 and the inclined section 17 being an acute angle less than 90 degrees. This acute angle design not only facilitates the smooth flow of high-temperature waste gas but also allows subsequent spray water to naturally flow back towards the double-cone duct 1 by gravity, avoiding water accumulation or blockage at the bends in the branch pipe. A first spray device 6 is installed within the inclined section 17 of the exhaust branch pipe 29. This first spray device 6 is located at the end of the inclined section 17 away from the double-cone duct 1, and its spray direction is towards the double-cone duct 1. When the nearly 200-degree Celsius high-temperature exhaust gas from the drying oven enters the induced draft branch pipe 29, the large amount of water mist sprayed by the first spray device 6 instantly cools the exhaust gas rapidly. Simultaneously, the water mist captures dust particles and sticky oil mist in the exhaust gas, completing the pretreatment of the exhaust gas. This pretreatment step reduces the load on subsequent processing units. At the same time, the first spray device 6 also serves as the first line of defense against initial fires. If sparks appear in the drying oven and are discharged with the exhaust gas, the sprayed water mist can immediately cool and extinguish them. To facilitate equipment maintenance, a cleaning window is provided on the outer wall at the connection between the vertical section 16 and the inclined section 17 of the induced draft branch pipe 29, and a removable sealing plate 18 is provided to close this window. Operators can open the sealing plate 18 to observe or clean the inside of the induced draft branch pipe 29 when the equipment is stopped, especially at the vertical section 16, further reducing the difficulty of daily maintenance.

[0026] like Figure 1 As shown, the pretreated exhaust gas then enters the horizontally arranged double-cone duct 1 from the exhaust branch pipe 29. The diameter of the double-cone duct 1 is designed to be smaller towards both ends, forming a double-cone symmetrical structure with small diameters at both ends and a large diameter in the middle. As the exhaust gas flows from the small diameter at one end to the large diameter in the middle, and then back to the small diameter at the other end, the flow velocity changes regularly, naturally generating continuous swirling turbulence inside the pipe. This swirling turbulence helps to collide and agglomerate the fibers and tiny oil droplets carried in the exhaust gas into larger particles, facilitating subsequent flushing with water. The central pipe 2 is vertically positioned in the middle of the double-cone duct 1 and connects to its interior, serving as the exhaust gas collection hub and primary purification container. A second spray device and a third spray device are respectively arranged inside the double-cone duct 1 and the central pipe 2. As the exhaust gas is transported along the more than 30-meter-long double-cone duct 1 to the central duct 2, a second spray device continuously sprays water mist to thoroughly clean the inner wall of the duct. Once the exhaust gas enters the central duct 2, a third spray device continues high-density spray washing. This design ensures that the exhaust gas remains wet-washed throughout its entire transport path from the drying chamber outlet to the primary purifier. Oil and lint are carried by the water mist and promptly discharged from the end or bottom of the duct, preventing stubborn oil buildup on the inner walls of the double-cone duct 1 and the central duct 2. This eliminates the need for traditional electrostatic or filtration equipment to periodically shut down and require significant manual labor for mechanical cleaning in narrow ducts. It truly achieves synchronous self-cleaning of the exhaust gas collection and transport pipeline during the purification process, reducing the company's operational and maintenance pressure and avoiding production losses due to cleaning shutdowns. In addition, an emergency vent 19 is provided at the top of the central tube 2. When the internal pressure of the system increases suddenly due to an unexpected situation, the emergency vent 19 will automatically open to release pressure, effectively preventing the equipment from being damaged due to overpressure and improving the operational safety of the device in continuous industrial production.

[0027] like Figure 1 and Figure 2As shown, in the exhaust gas power output and deep purification stage, the first spray device 6, the second spray device, and the third spray device together form the primary purification device. The gas that has been preliminarily purified enters the subsequent treatment unit through the suction action of the exhaust fan 5. The exhaust fan 5 is located at the outlet end of the third-stage exhaust pipe 12, that is, at the end of the entire purification process. It draws in the low-temperature clean gas that has been cooled and purified by multi-stage spraying, rather than directly drawing in the high-temperature oily exhaust gas discharged from the drying room. Therefore, the fan blades are not prone to oil contamination, the dynamic balance stability is good, the equipment failure rate is low, and the maintenance cost is reduced. The secondary cyclone purifier 3 includes a secondary purification tank 7, a secondary air inlet pipe 8, and a secondary air outlet pipe 9. The secondary purification tank 7 consists of a vortex-shaped upper tank and a cone-shaped lower tank. One end of the secondary air inlet pipe 8 is connected to the outlet of the exhaust fan 5, and the other end is connected to the upper tank tangentially to the outer peripheral wall of the upper tank. After the exhaust gas is injected tangentially at high speed into the vortex-shaped upper tank, a high-speed rotating airflow is formed. Under centrifugal force, residual fine dust and oil mist are thrown against the tank wall, converging into a liquid film that flows downwards along the conical lower tank wall. The secondary exhaust pipe 9 is located at the center of the top surface of the upper tank, with one end extending downwards into the lower tank after entering the secondary purification tank 7. This structure forces the purified gas to spiral upwards from the central region of the rotating airflow before being discharged, further improving gas-solid separation efficiency.

[0028] like Figure 1 , Figure 2 and Figure 5 As shown, the gas after secondary purification then enters the tertiary cyclone purifier 4 for final processing. The tertiary cyclone purifier 4 includes a tertiary purification tank 10, a tertiary inlet pipe 11, and a tertiary outlet pipe 12. The tertiary purification tank 10 has a partition plate 13 that divides the space inside into an upper cavity and a lower cavity. The lower cavity includes an upper vortex cavity and a lower conical cavity. A connecting pipe 14 is located at the center of the partition plate 13, with its lower end extending downwards into the conical cavity. One end of the tertiary inlet pipe 11 is tangentially connected to the vortex cavity, causing the exhaust gas to form a high-speed swirling flow within the vortex cavity and further compressed and rotated within the conical cavity to enhance the centrifugal separation effect. The other end of the tertiary inlet pipe 11 is connected to the secondary outlet pipe 9, thus connecting the tertiary cyclone purifier 3 and the tertiary cyclone purifier 4. The airflow then rises and reverses direction, entering the upper cavity through the connecting pipe 14. A baffle plate 15, parallel to the partition plate 13, is also installed in the upper cavity. This baffle plate 15 is used to block and trap residual water droplets and trace amounts of oil mist carried in the rising airflow. Finally, the purified clean gas is discharged from the third-stage exhaust pipe 12 located at the center of the top surface of the third-stage purification tank 10, and is led to the exhaust pipe 30 by the exhaust fan 5 and discharged into the atmosphere. One end of the exhaust fan 5 is connected to the third-stage exhaust pipe 12, and the other end of the exhaust fan 5 is connected to the exhaust pipe 30. The exhaust fan 5 provides negative pressure for the gas flow, serving as the driving force for the gas flow.

[0029] like Figure 1 As shown, to enhance the purification effect, secondary and tertiary mixed-flow spray pipes are respectively installed inside the secondary intake pipe 8 and the tertiary intake pipe 11. These two spray pipes spray water mist the instant the exhaust gas enters the secondary and tertiary cyclone purifiers 4, causing the spray water to mix powerfully with the high-speed rotating airflow. This not only provides further cooling and washing but also enhances the capture effect of fine particulate matter and oil mist, ensuring that the pollutant concentration in the final discharged gas consistently meets the current national emission standards. Furthermore, alkaline agents are installed inside the secondary and tertiary mixed-flow spray pipes to remove VOCs from the exhaust gas, further improving the purification performance. Through this three-stage wet cyclone spray series combination, this device eliminates the need for high-power electrostatic electrodes and frequently replaced, costly hazardous waste filter cartridges, reducing long-term operating costs in terms of both electricity and consumables.

[0030] like Figure 1 and Figure 4 As shown, this device is also equipped with a complete circulating water treatment system. The lower ends of the central pipe 2, the secondary purification tank 7, and the tertiary purification tank 10 are all equipped with outlets to discharge the oil-water mixture collected at the bottom of each purification unit. To maximize water conservation and reduce wastewater discharge, this device employs a three-stage overflow water supply system. The first, second, and third spray devices are all supplied with water from the first overflow tank 20; the secondary mixed-flow spray pipes are supplied with water from the second overflow tank 21; and the tertiary mixed-flow spray pipes are supplied with water from the third overflow tank 22. The third overflow tank 22 uses clean tap water as its makeup water source to ensure optimal washing performance for the final stage of spraying. The relatively clean liquid overflowing from the third overflow tank 22 automatically flows into the second overflow tank 21 through pipelines. The liquid overflowing from the second overflow tank 21 then automatically flows into the first overflow tank 20, thus completing the tiered utilization of water quality—the cleanest water is used for the final spray stage, while the more turbid water is used for the preliminary coarse washing, improving the efficiency of water resource utilization. Simultaneously, the outlets of the central pipe 2, the secondary purification tank 7, and the tertiary purification tank 10 are respectively connected to an oil-water separation circulating water processor, a secondary oil-water separator 23, and a tertiary oil-water separator 24. These oil-water separators efficiently separate the oil-water mixture discharged from each purification unit. The separated waste oil can be collected for resource recycling, while the separated water is returned to the first overflow tank 20 and the second overflow tank 21 for recycling, depending on its cleanliness level. Through the above-mentioned cascade water replenishment and circulation separation design, the entire system only needs to replenish a small amount of tap water to the third overflow tank 22 to maintain long-term stable operation, reducing wastewater discharge and fresh water consumption, and lowering daily water costs and waste liquid disposal costs.

[0031] The first spray device 6, the second spray device, the third spray device, the secondary mixed-flow spray pipe, and the tertiary mixed-flow spray pipe are connected to the corresponding first overflow tank 20, second overflow tank 21, and third overflow tank 22 via independent water supply branch pipes. Each water supply branch pipe is equipped with an electromagnetic shut-off valve and a flow regulating valve. Each spray device adopts a ring-shaped water distribution pipeline, with the nozzles evenly arranged along the circumference of the pipe wall, and the spray direction forming an angle of 30° to 60° with the airflow direction. The electromagnetic shut-off valve and the flow regulating valve are electrically connected to a PLC controller, which is connected to the frequency converter signal of the exhaust fan 5. After the exhaust fan 5 is started, the PLC controller opens the water supply valves of each spray device in a preset sequence, and dynamically adjusts the water supply flow and spray water pressure of each spray branch pipe based on the feedback signals from the pressure sensors and temperature sensors installed inside the central pipe 2, the secondary purification tank 7, and the tertiary purification tank 10.

[0032] like Figure 1 As shown, this device is also modularized and designed for ease of use based on actual production needs. The double-cone duct 1, central duct 2, secondary cyclone purifier 3, tertiary cyclone purifier 4, and exhaust fan 5 together form a complete waste gas treatment unit. In practical applications, multiple waste gas treatment units can be set up to operate in parallel, depending on the number of ovens and the required air volume of the stenter. The exhaust fan 5 of each waste gas treatment unit is connected to the same main duct 27 for waste gas collection, which in turn connects to the final exhaust pipe 30. A maintenance platform 28 is fixedly installed on the outer wall of the main duct 27, facilitating daily inspection and maintenance of the collection section by maintenance personnel. A detection platform 25 is also installed near the outlet of the exhaust pipe 30, with a detection ladder 26 connected to it, allowing environmental regulators to periodically sample and test the emission outlets, ensuring real-time transparency and compliance of emission data.

[0033] Finally, this device has outstanding advantages in terms of safety and fire prevention. Throughout the entire operation of the device, from the first spray device 6 in the exhaust branch pipe 29, to the second spray device in the double-cone duct pipe 1, the third spray device in the central pipe 2, and then to the mixed-flow spray pipes in the secondary air intake pipe 8 and the tertiary air intake pipe 11, all spray units are always in a state of continuous water mist spraying. When an initial spark or low-energy fire occurs unexpectedly inside the setting machine drying room, the high-temperature spark enters the exhaust duct system with the exhaust gas flow. As it flows through all the above-mentioned spray areas, the dense low-temperature water mist can quickly envelop and cool the spark particles, extinguishing them in a very short time. At the same time, a large amount of water mist vaporizes and absorbs heat, effectively reducing the flue gas temperature and blocking the path of the fire to spread outside the workshop along the pipes and purification equipment. This fully wet washing structure fundamentally eliminates the major safety hazards of high-voltage arcing caused by oil buildup on the plates in traditional electrostatic equipment, and fires caused by spontaneous combustion of oil in the filter element in filtration equipment. This makes the device not only a waste gas purification device, but also has the safety functions of automatic fire extinguishing and active fire prevention in the initial stage of fire, providing dual protection for the safe production of printing and dyeing enterprises.

[0034] In summary, this stenter exhaust gas treatment device achieves stable and compliant emissions of stenter exhaust gas without relying on electrostatic adsorption or filtration interception technologies through the synergistic effects of cyclone collection in the double-cone duct 1, multi-stage wet spray separation via the central pipe 2 and various cyclone purifiers, and a three-stage overflow water circulation system. Simultaneously, the device achieves self-cleaning of pipes and purification units through continuous spray washing, eliminating the arduous labor of manual shutdown cleaning; it reduces water and electricity consumption and waste liquid disposal costs through tiered water use and oil-water separation circulation; and it effectively suppresses and extinguishes initial sparks through a continuous wet water mist environment, effectively eliminating fire hazards to a certain extent. This invention specifically addresses the three long-standing pain points of existing technologies: high operating costs, difficult maintenance, and significant fire risks. It has energy-saving and environmental protection benefits and high industrial application value, providing reliable technical support for the green and safe production of dyeing and printing enterprises.

[0035] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A device for treating exhaust gas from a stenter, characterized in that: It includes a double-cone duct (1), a central pipe (2), a secondary cyclone purifier (3), a tertiary cyclone purifier (4), and an exhaust fan (5). The double-cone duct (1) is connected to the shaping machine through an exhaust branch pipe (29). A first spray device (6) is installed in the exhaust branch pipe (29). The diameter of the double-cone duct (1) is smaller as it approaches the two ends of the double-cone duct (1). The central pipe (2) is located in the middle of the double-cone duct (1) and is connected to the double-cone duct (1). A second spray device and a third spray device are respectively installed in the double-cone duct (1) and the central pipe (2). The secondary cyclone purifier (3) includes a secondary purification tank (7), a secondary air inlet pipe (8), and a secondary air outlet pipe (9). The secondary purification tank (7) includes an upper tank in the shape of a vortex and a lower tank in the shape of a cone. The secondary purification tank (7) is connected to the central pipe (2) through the secondary air inlet pipe (8). The secondary air inlet pipe (8) is tangent to the outer peripheral wall of the upper tank. The secondary air outlet pipe (9) is located at the center of the top surface of the upper tank and one end of the secondary air outlet pipe (9) inside the secondary purification tank (7) extends to the lower tank. The three-stage cyclone purifier (4) includes a three-stage purification tank (10), a three-stage air inlet pipe (11), and a three-stage air outlet pipe (12). A partition plate (13) is provided inside the three-stage purification tank (10). The partition plate (13) divides the space inside the three-stage purification tank (10) into an upper cavity and a lower cavity. The lower cavity includes a vortex cavity and a conical cavity. The vortex cavity is located above the conical cavity. A connecting pipe (14) is provided at the center of the partition plate (13). The lower end of the connecting pipe (14) extends into the conical cavity. The three-stage air inlet pipe (11) is connected to the vortex cavity and is tangent to the outer wall of the vortex cavity. A flow-blocking plate (15) parallel to the partition plate (13) is provided inside the upper cavity. The three-stage air outlet pipe (12) is located at the center of the top surface of the three-stage purification tank (10) and is connected to the upper cavity. One end of the exhaust fan (5) is connected to the third-stage exhaust pipe (12), and the other end of the exhaust fan (5) is connected to the smoke exhaust pipe (30). The second-stage air inlet pipe (8) and the third-stage air inlet pipe (11) are respectively equipped with a second-stage mixed flow spray pipe and a third-stage mixed flow spray pipe. The lower ends of the central pipe (2), the second-stage purification tank (7) and the third-stage purification tank (10) are all equipped with liquid outlets.

2. The waste gas treatment device for a stenter according to claim 1, characterized in that: The air intake branch pipe (29) includes a vertical section (16) and an inclined section (17). The vertical section (16) is connected to the shaping machine. The inclined section (17) is inclined toward the double cone air duct pipe (1) and the included angle between the vertical section (16) and the inclined section (17) is less than 90 degrees. The first spray device (6) is set at the end of the inclined section (17) away from the double cone air duct pipe (1) and the spraying direction of the first spray device (6) is set toward the double cone air duct pipe (1).

3. The waste gas treatment device for a stenter according to claim 2, characterized in that: A cleaning window is provided at the connection between the vertical section (16) and the inclined section (17), and a sealing plate (18) for closing the cleaning window is provided on the air duct (29).

4. The waste gas treatment device for a stenter according to claim 1, characterized in that: The top of the central tube (2) is provided with an emergency vent (19).

5. The waste gas treatment device for a stenter according to claim 1, characterized in that: The first spray device (6), the second spray device and the third spray device are all supplied with water by the first overflow pool (20), the secondary mixed flow spray pipe is supplied with water by the second overflow pool (21), the tertiary mixed flow spray pipe is supplied with water by the third overflow pool (22), the liquid overflowing from the third overflow pool (22) flows into the second overflow pool (21), and the liquid overflowing from the second overflow pool (21) flows into the first overflow pool (20). The outlets of the central pipe (2), the secondary purification tank (7) and the tertiary purification tank (10) are respectively connected to an oil-water separation circulating water processor, a secondary oil-water separation device (23) and a tertiary oil-water separation device (24). The liquid separated by the secondary oil-water separation device (23) flows into the first overflow pool (20), and the liquid separated by the tertiary oil-water separation device (24) flows into the second overflow pool (21). The third overflow pool (22) is supplied with tap water.

6. The waste gas treatment device for a stenter according to claim 1, characterized in that: It also includes a testing platform (25), which is located near the outlet of the exhaust pipe (30), and a testing ladder (26) is connected to the testing platform (25).

7. The stenter exhaust gas treatment device according to claim 1, characterized in that: The double-cone duct (1), central duct (2), secondary cyclone purifier (3), tertiary cyclone purifier (4) and exhaust fan (5) together form a waste gas treatment unit. There are multiple waste gas treatment units. The air outlet of the exhaust fan (5) of each waste gas treatment unit is connected to the same main duct (27). The main duct (27) is then connected to the smoke exhaust pipe (30). A maintenance platform (28) is fixedly installed on the outer wall of the main duct (27).

Images