An electric steam boiler flue gas waste heat recovery and purification equipment

Abstract

This invention relates to the field of flue gas purification technology, specifically to a waste heat recovery and purification device for electric steam boiler flue gas, comprising a lower purification box and an upper purification box. The top of the lower purification box is connected to the upper purification box, and a spray inlet pipe is connected to one side of the upper purification box. An air inlet pipe is circumferentially connected to the middle of the lower purification box. A fixed frame is fixedly connected inside the upper purification box, and an outer guide hood is rotatably connected to the inner side of the fixed frame. This invention achieves circumferential uniform water distribution through the cooperation of a pressure equalizing ring and a guide inclined surface. A double-layer continuous annular water curtain is formed by the special inclination angle of the guide wall, preventing flue gas from escaping and significantly improving the collection efficiency of sticky dust and volatile components in the production of silicone PU and adhesives. The low-dust clean liquid is pumped back for reuse through an internal spiral pair composed of a hollow tube and a threaded conveying pipe. A third water curtain is formed by the high-speed rotation of the umbrella-shaped hood. The reuse of the low-dust liquid reduces the amount of treatment liquid replenishment, indirectly reducing the energy consumption for replenishment water heating.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification technology, and in particular to a waste heat recovery and purification device for flue gas from an electric steam boiler. Background Technology

[0002] In the production of polymer compounds such as silicone polyurethane (PU) materials and construction adhesives, a typical process involves: producing adhesives, mixing materials, and silicone PU; stirring in a reactor; and heating the mixture in a gas-fired steam boiler to produce the finished product. During operation, the gas-fired steam boiler generates a large amount of high-temperature flue gas.

[0003] However, existing technologies for exhaust gas treatment in the aforementioned specific production scenarios still have the following problems: most only have a single fixed spray layer, and the flue gas can easily short-circuit through the central area with low resistance, failing to fully contact the droplets. This results in low collection efficiency of sticky organic dust generated during the production of adhesives and silicone PU, and the purified flue gas still easily carries odors and residual pollutants. Existing equipment lacks the ability to grade the mixed liquid after washing. The mixed liquid containing the collected dust is discharged uniformly regardless of the dust content. Reusing the collected liquid can reduce operating costs, but existing reuse schemes require additional centrifugal pumps and long external return water pipelines, which not only occupy limited production space but are also prone to reuse failure due to slurry blockage and pump wear. Furthermore, the reused liquid cannot be linked with the top atomizing structure to form a secondary purification water curtain, resulting in a single purification level that is difficult to meet ultra-low emission requirements. Therefore, an electric steam boiler flue gas waste heat recovery and purification device is proposed to solve the above-mentioned problems. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the background art by proposing a waste heat recovery and purification device for flue gas from an electric steam boiler.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A waste heat recovery and purification device for flue gas from an electric steam boiler includes a lower purification box and an upper purification box. The top of the lower purification box is connected to the upper purification box, a spray liquid inlet pipe is connected to one side of the upper purification box, and an air inlet pipe is circumferentially connected to the middle of the lower purification box. The upper purification box is fixedly connected to a fixed frame. The inner side of the fixed frame is rotatably connected to an outer guide hood. The bottom of the outer guide hood has evenly distributed liquid outlets. Each liquid outlet has a guide baffle on both sides. The guide baffle is fixedly connected to the outer guide hood. A conical base is fixedly connected to the inner side of the guide baffle. A hollow tube is fixedly connected to the middle of the conical base. A gear ring is fixed to the outer wall of the outer guide shield, a drive gear meshes with the outer wall of the gear ring, a drive motor is provided at the bottom of the drive gear, and the drive motor is installed inside the fixed frame. The outer wall of the hollow tube is rotatably connected to a pressure equalizing ring. The bottom of the pressure equalizing ring is provided with two evenly distributed liquid outlets. The inside of the pressure equalizing ring is connected to the spray inlet pipe. The bottom of the upper purification chamber is provided with a flow guide wall, and the bottom of the hollow tube is provided with a fluid acceleration mechanism.

[0006] Preferably, a threaded conveying pipe is provided inside the hollow tube, a connecting rod is fixedly connected to the top of the threaded conveying pipe, a filter plate is fixedly connected to the top of the connecting rod, and the outer side of the filter plate is fixedly connected to the inside of the upper purification box.

[0007] Preferably, a liquid collection tank is fixed to the top of the hollow tube, and an umbrella-shaped cover is fixed to the outside of the liquid collection tank.

[0008] Preferably, the fluid acceleration mechanism includes a liquid acceleration chamber, which is fixedly connected to the interior of the lower purification chamber by fixing rods on both sides. The top of the liquid acceleration chamber is provided with a sloping guide groove, and four threaded pipe grooves are provided between the sloping guide groove and the liquid acceleration chamber.

[0009] Preferably, the four threaded tube grooves are evenly distributed vertically, and the ends of the four threaded tube grooves are connected by vertical grooves, with a tangential liquid inlet pipe connected to the bottom of the vertical grooves.

[0010] Preferably, the bottom of the liquid acceleration chamber is connected to a cyclone separation chamber, and the end of the tangential inlet pipe away from the threaded groove is connected to the cyclone separation chamber along the tangential direction at the top of the cyclone separation chamber.

[0011] Preferably, an internal cavity is formed between the lower purification chamber, the liquid acceleration chamber, and the cyclone separation chamber to allow flue gas to circulate.

[0012] Preferably, the top of the upper purification box is connected to a vent pipe, and the bottom of the vent pipe is connected to an air pump.

[0013] Compared with existing technologies, the advantages of this invention are as follows: This invention achieves uniform circumferential water distribution of the treatment liquid through the cooperation of a pressure equalizing ring and a guide slope. The special inclination design of the guide wall guides the liquid film to converge towards the center, naturally forming a second annular water curtain and extending the gas-liquid contact time. Combined with the double-layer annular water curtain formed by rotation, it completely eliminates the short-circuiting phenomenon of flue gas, significantly improving the collection efficiency of viscous organic dust and volatile components generated in the production of silicone PU and adhesives, ensuring a deep purification process. The cyclone separation chamber automatically classifies high- and low-dust droplets, only reusing the low-dust clear liquid through a spiral pump consisting of a built-in hollow tube and a threaded conveying pipe. After accumulating liquid in the collection tank, it is sprayed along an umbrella-shaped hood. The shear force generated by high-speed rotation forms a third water curtain, ultimately intercepting escaped fine particles. The equipment integrates flue gas purification and filtrate recycling. The reuse of low-dust liquid reduces the amount of treatment liquid replenishment, indirectly reducing the energy consumption for replenishment heating. Furthermore, the overall structure is compact and highly compatible with the existing reactor and gas boiler process layouts of adhesive and silicone PU production enterprises. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the purification box of the present invention; Figure 3 This is the present invention. Figure 2 Schematic diagram of the structure at point A in the middle; Figure 4 This is a partial structural diagram of the internal structure of the purification box of this invention; Figure 5 This is a schematic diagram of the structure of the pressure equalization ring of the present invention; Figure 6 This is a schematic diagram of the internal structure of the outer guide shield of the present invention; Figure 7 This is a top view schematic diagram of the liquid acceleration chamber structure of the present invention; Figure 8 This is a schematic diagram of the internal structure of the cyclone separation chamber of the present invention; Figure 9 This is the present invention. Figure 8 Schematic diagram of the structure at point B.

[0015] In the diagram: 1. Suction pump; 2. Ventilation pipe; 3. Upper purification box; 4. Spray inlet pipe; 5. Air inlet pipe; 6. Lower purification box; 7. Filter plate; 8. Umbrella-shaped cover; 9. Hollow tube; 10. Pressure equalizing ring; 11. Outer guide hood; 12. Fixing frame; 13. Guide baffle; 14. Outlet 1; 15. Guide wall; 16. Conical base; 17. Gear ring; 18. Drive motor; 19. Drive gear; 20. Threaded delivery pipe; 21. Liquid collection tank; 22. Outlet 2; 23. Internal cavity; 24. Liquid acceleration chamber; 25. Inclined guide groove; 26. Threaded pipe groove; 27. Swirl separation chamber; 28. Tangential inlet pipe; 29. ​​Fixing rod; 30. Connecting rod. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Reference Figures 1-9 A waste heat recovery and purification device for flue gas from an electric steam boiler includes a lower purification box 6 and an upper purification box 3. The top of the lower purification box 6 is connected to the upper purification box 3. A spray liquid inlet pipe 4 is connected to one side of the upper purification box 3. An air inlet pipe 5 is circumferentially connected to the middle of the lower purification box 6. A fixed frame 12 is fixedly connected inside the upper purification box 3. An outer guide hood 11 is rotatably connected to the inner side of the fixed frame 12. The bottom of the outer guide hood 11 is provided with evenly distributed liquid outlets 14. Each liquid outlet 14 is provided with a guide baffle 13 on both sides. The guide baffle 13 is fixedly connected to the outer guide hood 11. A conical base 16 is fixedly connected to the inner side of the guide baffle 13. A hollow tube 9 is fixedly connected to the middle of the conical base 16. The outer wall of the hollow tube 9 is rotatably connected to a pressure equalizing ring 10. The bottom of the pressure equalizing ring 10 is provided with a uniformly distributed liquid outlet 22. The inside of the pressure equalizing ring 10 is connected to the spray inlet pipe 4.

[0019] In this embodiment, an external water pump pumps the treatment liquid into the pressure equalizing ring 10 via the spray inlet pipe 4, while the flue gas enters through the inlet pipe 5. After the liquid completes circumferential pressure stabilization within the pressure equalizing ring 10, it is sprayed out through the second liquid outlet 22, falls onto the guide slope formed by the guide baffle 13 and the conical base 16, and, with the help of gravity and centrifugal pre-distribution, finally overflows evenly through several liquid outlets 14.

[0020] The top of the upper purification box 3 is connected to the ventilation pipe 2, and the bottom of the ventilation pipe 2 is connected to the suction pump 1. A gear ring 17 is fixedly connected to the outer wall of the outer guide shroud 11. A drive gear 19 meshes with the outer wall of the gear ring 17. A drive motor 18 is provided at the bottom of the drive gear 19. The drive motor 18 is installed inside the fixed frame 12.

[0021] In this embodiment, simultaneously, the drive motor 18 on the fixed frame 12 starts, and through the drive gear 19 meshing with the gear ring 17, drives the outer guide shroud 11 and its upper components to rotate synchronously. The liquid flowing out from the outlet 14 is thrown out by centrifugal force during the high-speed rotation of the outer guide shroud 11 and forms the first annular water curtain at the edge of the conical base 16.

[0022] The bottom of the upper purification box 3 is provided with a flow guide wall 15, and the bottom of the hollow tube 9 is provided with a fluid acceleration mechanism.

[0023] In this implementation scheme, under the guidance of the guide wall 15, some of the liquid film does not fall directly, but flows towards the center along the bottom edge of the guide wall 15, thereby forming a second annular water curtain. This forces the flue gas to penetrate the liquid film a second time during its ascent, significantly prolonging the gas-liquid contact time and allowing the flue gas and liquid droplets to have full and efficient contact. Through the two water curtains, each stream of flue gas can meet the requirements of deep purification.

[0024] The fluid acceleration mechanism includes a liquid acceleration chamber 24, which is fixed to the interior of the lower purification box 6 by fixing rods 29 on both sides. The top of the liquid acceleration chamber 24 is provided with a sloping guide groove 25, and four threaded pipe grooves 26 are provided between the sloping guide groove 25 and the liquid acceleration chamber 24.

[0025] The four threaded tube grooves 26 are evenly distributed vertically, and the tail ends of the four threaded tube grooves 26 are connected by vertical grooves. The bottom of the vertical grooves is connected to a tangential liquid inlet pipe 28.

[0026] The bottom of the liquid acceleration chamber 24 is connected to the cyclone separation chamber 27, and the end of the tangential liquid inlet pipe 28 away from the threaded pipe groove 26 is connected to the cyclone separation chamber 27 along the tangential direction at the top of the cyclone separation chamber 27.

[0027] In this embodiment, droplets carrying the captured dust fall through the first two water curtains and land on the inclined guide channel 25. Guided by the inclined guide channel 25, the mixture enters the threaded tube channel 26. Under the combined action of the centrifugal force field generated by rotation and gravity, the mixture is accelerated and the swirling flow is enhanced in the threaded tube channel 26, and then it converges into the tangential inlet pipe 28.

[0028] Liquid is injected into the cyclone separation chamber 27 along the tangential direction at the end of the tangential inlet pipe 28, forming a strong swirling flow field in the chamber: high dust liquid with a large dust content is thrown towards the chamber wall and discharged downward due to centrifugal force; while low dust droplets containing fine particles or even no solids are driven upward through the hollow tube 9 at the top due to their lighter mass and the effect of gas drag and centripetal flow.

[0029] The hollow tube 9 has a threaded conveying pipe 20 inside, a connecting rod 30 is fixed to the top of the threaded conveying pipe 20, a filter plate 7 is fixed to the top of the connecting rod 30, and the outer side of the filter plate is fixed to the inside of the upper purification box.

[0030] A liquid collection tank 21 is fixedly connected to the top of the hollow tube 9, and an umbrella-shaped cover 8 is fixedly connected to the outside of the liquid collection tank 21.

[0031] The lower purification chamber 6 forms an internal cavity 23 between the liquid acceleration chamber 24 and the cyclone separation chamber 27 for flue gas circulation.

[0032] In this embodiment, the hollow tube 9 rotates synchronously with the outer guide shroud 11, forming a spiral conveying mechanism with the internally fixed threaded conveying tube 20. This structure applies axial thrust to the upward-migrating low-dust droplets, efficiently conveying them along the threaded channel to the collection tank 21 at the top of the hollow tube 9. When the liquid accumulation in the collection tank 21 reaches a threshold, the liquid is thrown outward along the surface of the umbrella-shaped shroud 8, forming a third high-speed annular water curtain under centrifugal force, deeply scrubbing the flue gas, ultimately achieving ultra-low emissions and tiered capture of pollutants.

[0033] Working principle: When the boiler flue gas is treated, an external water pump pumps the treatment liquid into the pressure equalizing ring 10 through the spray inlet pipe 4, while the flue gas enters through the inlet pipe 5. After the liquid is circumferentially pressure-stabilized within the pressure equalizing ring 10, it is sprayed out through the second liquid outlet 22 and falls onto the guide slope formed by the guide baffle 13 and the conical base 16. With the help of gravity and centrifugal pre-distribution, it finally overflows evenly through several liquid outlets 14.

[0034] At the same time, the drive motor 18 on the fixed frame 12 starts, and through the drive gear 19 meshing with the gear ring 17, it drives the outer guide shroud 11 and its upper components to rotate synchronously. The liquid flowing out from the liquid outlet 14 is thrown out by centrifugal force during the high-speed rotation of the outer guide shroud 11 and forms the first annular water curtain at the edge of the conical base 16.

[0035] Guided by the guide wall 15, some of the liquid film does not fall directly, but flows towards the center along the bottom edge of the guide wall 15, thus forming a second annular water curtain. This forces the flue gas to penetrate the liquid film a second time during its ascent, significantly extending the gas-liquid contact time and allowing the flue gas and liquid droplets to have full and efficient contact. Through the two water curtains, each stream of flue gas can meet the requirements of deep purification.

[0036] Droplets carrying the captured dust fall through the first two water curtains and land on the inclined guide channel 25. Guided by the inclined guide channel 25, the mixture enters the threaded tube channel 26. Under the combined action of the centrifugal force field generated by rotation and gravity, the mixture is accelerated and the swirling flow is enhanced in the threaded tube channel 26, and then it converges into the tangential inlet pipe 28.

[0037] Liquid is injected into the cyclone separation chamber 27 along the tangential direction at the end of the tangential inlet pipe 28, forming a strong swirling flow field in the chamber: high dust liquid with a large dust content is thrown towards the chamber wall and discharged downward due to centrifugal force; while low dust droplets containing fine particles or even no solids are driven upward through the hollow tube 9 at the top due to their lighter mass and the effect of gas drag and centripetal flow.

[0038] The hollow tube 9 rotates synchronously with the outer guide shroud 11, forming a spiral conveying mechanism with the internally fixed threaded conveying tube 20. This structure applies axial thrust to the upward-migrating low-dust droplets, efficiently conveying them along the threaded channel to the collection tank 21 at the top of the hollow tube 9. When the liquid accumulation in the collection tank 21 reaches a threshold, the liquid is thrown outward along the surface of the umbrella-shaped shroud 8, forming a third high-speed annular water curtain under centrifugal force, deeply scrubbing the flue gas, ultimately achieving ultra-low emissions and tiered capture of pollutants.

[0039] To further clarify, the aforementioned fixed connection should be interpreted broadly unless otherwise explicitly specified and limited. For example, it may be welding, gluing, or integral molding, or other conventional methods well known to those skilled in the art.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A waste heat recovery and purification device for flue gas from an electric steam boiler, comprising a lower purification box (6) and an upper purification box (3), characterized in that, The top of the lower purification box (6) is connected to the upper purification box (3), and a spray inlet pipe (4) is connected to one side of the upper purification box (3). An air inlet pipe (5) is connected to the middle of the lower purification box (6). The upper purification box (3) is fixedly connected to a fixed frame (12). The inner side of the fixed frame (12) is rotatably connected to an outer guide hood (11). The bottom of the outer guide hood (11) is provided with evenly distributed liquid outlets (14). Each liquid outlet (14) is provided with a guide baffle (13) on both sides. The guide baffle (13) is fixedly connected to the outer guide hood (11). The inner side of the guide baffle (13) is fixedly connected to a conical base (16). The middle part of the conical base (16) is fixedly connected to a hollow tube (9). A gear ring (17) is fixed to the outer wall of the outer guide shield (11), and a drive gear (19) is meshed on the outer wall of the gear ring (17). A drive motor (18) is provided at the bottom of the drive gear (19), and the drive motor (18) is installed inside the fixed frame (12). The outer wall of the hollow tube (9) is rotatably connected to a pressure equalizing ring (10). The bottom of the pressure equalizing ring (10) is provided with two evenly distributed liquid outlets (22). The inside of the pressure equalizing ring (10) is connected to the spray inlet pipe (4). The bottom of the upper purification box (3) is provided with a flow guide wall (15), and the bottom of the hollow tube (9) is provided with a fluid acceleration mechanism.

2. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 1, characterized in that: The hollow tube (9) is equipped with a threaded conveying pipe (20), and a connecting rod (30) is fixed to the top of the threaded conveying pipe (20). A filter plate (7) is fixed to the top of the connecting rod (30), and the outer side of the filter plate (7) is fixed to the inside of the upper purification box (3).

3. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 1, characterized in that: A liquid collection tank (21) is fixed to the top of the hollow tube (9), and an umbrella-shaped cover (8) is fixed to the outside of the liquid collection tank (21).

4. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 1, characterized in that: The fluid acceleration mechanism includes a liquid acceleration chamber (24), which is fixed to the interior of the lower purification box (6) by fixing rods (29) on both sides. A sloping guide groove (25) is provided on the top of the liquid acceleration chamber (24), and four threaded pipe grooves (26) are provided between the sloping guide groove (25) and the liquid acceleration chamber (24).

5. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 4, characterized in that: The four threaded tube grooves (26) are evenly distributed vertically, and the tail ends of the four threaded tube grooves (26) are connected by vertical grooves. The bottom of the vertical grooves is connected to a tangential liquid inlet pipe (28).

6. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 5, characterized in that: The bottom of the liquid acceleration chamber (24) is connected to the cyclone separation chamber (27), and the end of the tangential liquid inlet pipe (28) away from the threaded pipe groove (26) is connected to the cyclone separation chamber (27) along the tangential direction of the top of the cyclone separation chamber (27).

7. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 6, characterized in that: An internal cavity (23) is formed between the lower purification chamber (6), the liquid acceleration chamber (24), and the cyclone separation chamber (27) for flue gas circulation.

8. The waste heat recovery and purification equipment for electric steam boiler flue gas according to claim 1, characterized in that: The top of the upper purification box (3) is connected to a ventilation pipe (2), and the bottom of the ventilation pipe (2) is connected to an air pump (1).

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