Composite tube flue gas split type anti-corrosion air preheater and its ash cleaning device

Abstract

The application discloses a composite pipe flue gas shunt type anti-corrosion air preheater and a dust cleaning device thereof, and belongs to the technical field of pipeline dust cleaning equipment. The air preheater comprises a shell and pipe boxes for sealing the two end portions of the shell, the pipe boxes are connected with the shell through pipe plates, a tube bundle is loaded in the shell, the tube bundle is composed of a plurality of bundle plates and a plurality of heat exchange pipes, the bundle plates at least include a first bundle plate and a second bundle plate, a plurality of vertical baffles are installed in the middle portion of the first bundle plate, a plurality of horizontal baffles are installed in the middle portion of the second bundle plate, the first bundle plate and the second bundle plate are arranged in multiple groups in the shell in a staggered mode, the heat exchange pipes are inserted into the second installation grooves among the multiple horizontal baffles along the first installation grooves among the adjacent vertical baffles, the end portions of the heat exchange pipes away from each other are inserted into the pipe plates, and the dust cleaning device is placed in the heat exchange pipes and used for removing the fouling on the inner walls of the heat exchange pipes.

Description

Technical Field

[0001] This invention belongs to the technical field of pipeline cleaning equipment, specifically relating to a composite pipe flue gas diversion type anti-corrosion air preheater and its cleaning device. Background Technology

[0002] Air preheaters, as key heat exchange equipment in thermal systems such as coal-fired boilers and industrial kilns, play a crucial role in preheating combustion air using waste heat from flue gas, significantly improving system thermal efficiency. Traditional tubular air preheaters generally employ a fixed tube bundle structure, with flue gas longitudinally scouring the outer wall of the heat exchange tubes in the shell side and air flowing in the tube side. However, this structure faces two major bottlenecks in actual operation: low-temperature acid dew point corrosion at the flue gas outlet, and the air preheater being located in the lowest flue gas temperature zone within the boiler. The large amount of sulfur trioxide in the flue gas condenses into dew droplets when the heat exchange temperature drops to its dew point temperature, a process known as "condensation." This condensation forms highly corrosive sulfuric acid and sulfurous acid solutions, easily corroding metal equipment, affecting boiler heat exchange performance, and creating safety hazards.

[0003] Ash buildup in air preheaters obstructs or even blocks flue gas passages and hinders the adaptability of cleaning devices. Accumulated ash acts as insulation between the flue gas and the pipe wall, lowering the wall temperature and leading to low-temperature dew point corrosion. As the air preheater corrodes, the significant pressure difference between the inside and outside of the pipe wall increases leakage points, severely deteriorates surface smoothness, and makes it easier for ash to adhere, exacerbating ash buildup. Fixed scraper brushes, with their rigid structure, cannot conform to pipe walls with varying wear conditions, creating cleaning dead zones, and excessive scraping accelerates pipe wall thinning. Therefore, our company has developed a composite pipe flue gas diversion type anti-corrosion air preheater and its cleaning device to replace existing technologies. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a composite tube flue gas diversion type anti-corrosion air preheater and its cleaning device to solve the technical problems of fixed scraper brushes, rigid structures that are difficult to fit the pipe walls under different wear conditions, dead corners in cleaning, and excessive scraping that will accelerate the thinning of the pipe walls.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a composite tube flue gas diversion type anti-corrosion air preheater and its cleaning device, comprising a shell and tube boxes for sealing the two ends of the shell, the tube boxes and the shell are connected by tube plates, one side of the tube boxes located at the two ends of the shell is the air side, and the other end is the sealed side, the tube boxes on the air side are separated by extension plates, one end of the extension plate is connected to the inner wall of the air side tube box, and the other end is fixedly connected to the tube bundle, characterized in that the tube bundle is loaded in the shell, and the tube bundle is composed of multiple bundle plates and multiple heat exchange tubes;

[0006] The bundle plate includes at least a first bundle plate and a second bundle plate, wherein multiple vertical baffles are installed in the middle of the first bundle plate and multiple horizontal baffles are installed in the middle of the second bundle plate. Multiple sets of the first bundle plate and the second bundle plate are arranged alternately inside the shell. The heat exchange tubes are inserted into the second mounting groove between multiple horizontal baffles along the first mounting groove between adjacent vertical baffles. The ends of the heat exchange tubes that are far apart from each other are inserted into the tube sheet.

[0007] A cleaning device is placed inside the heat exchange tube and is used to remove scale buildup on the inner wall of the heat exchange tube.

[0008] Furthermore: the dust removal device includes a first sealing plate and a second sealing plate, a rotating shaft is installed between the first sealing plate and the second sealing plate, the rotating shaft is driven by a micro motor, and a scraping component is installed on the rotating shaft.

[0009] Further: The scraping assembly includes a first fixed ring, a sliding ring, and a second fixed ring. The first fixed ring and the second fixed ring are mounted on a rotating shaft. The first fixed ring is hinged to a first swing rod, and the second fixed ring is hinged to a second swing rod. The other ends of the first swing rod and the second swing rod are rotatably connected to a mounting base. A flexible brush is mounted on the mounting base. A sliding ring is also mounted on the rotating shaft. A third swing rod is hinged to the sliding ring. The other end of the third swing rod is hinged to the mounting base. A first tension spring is sleeved on the rotating shaft between the sliding ring and the first fixed ring or the second fixed ring. One end of the first tension spring is connected to the sliding ring, and the other end of the first tension spring is connected to the first fixed ring or the second fixed ring.

[0010] Furthermore, the flexible brush is a nylon brush, a wire brush, or a spring scraper, selected according to the material of the heat exchange tube.

[0011] Furthermore: the scraping assembly includes a connecting rod and an adjusting seat connected to the connecting rod. The adjusting seat has an adjusting groove for mounting the brush. A spring swing arm is rotatably connected to the adjusting seat. The spring swing arm is connected to a pressure plate. The pressure plate contacts the bottom of the brush. A second tension spring is fixedly installed on the adjusting seat. The other end of the second tension spring is fixedly connected to the spring swing arm.

[0012] Compared with the prior art, the present invention has the following advantages: by using staggered first and second bundle plates, the shell is divided into multiple flow zones, and the flue gas changes direction when flowing through each flow zone, thereby improving the heat exchange efficiency. The vertical baffle of the first bundle plate guides the flue gas to flow longitudinally and prolongs the flue gas residence time. The transverse baffle of the second bundle plate forces the flue gas to laterally flush the heat exchange tube. On the other hand, through a specially designed cleaning device, the sliding ring slides on the rotating shaft under the action of the first tension spring, so that the flexible brush is always in close contact with the inner wall of the heat exchange tube during the swinging process of the first swing rod, the second swing rod and the third swing rod, automatically compensating for local deformation of the tube diameter or local structural problems. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the air preheater of the present invention;

[0014] Figure 2 This is a structural diagram of the first bundle plate of the present invention;

[0015] Figure 3 This is a structural diagram of the second beam plate of the present invention;

[0016] Figure 4 The structure of the dust removal device of the present invention Figure 1 ;

[0017] Figure 5 The structure of the dust removal device of the present invention Figure 2 ;

[0018] Figure 6 This is the present invention. Figure 5 A magnified view of a portion of point A in the middle.

[0019] In the diagram: 1. Shell; 2. Tube box; 3. Tube sheet; 4. Tube bundle; 5. Heat exchange tube; 6. First bundle plate; 7. Second bundle plate; 8. Vertical baffle; 9. Horizontal baffle; 10. First mounting slot; 11. Second mounting slot; 12. First sealing plate; 13. Second sealing plate; 14. Rotating shaft; 15. First fixing ring; 16. Sliding ring; 17. Second fixing ring; 18. First swing rod; 19. Second swing rod; 20. Mounting seat; 21. Flexible brush; 22. Third swing rod; 23. First tension spring; 24. Connecting rod; 25. Adjusting seat; 26. Brush; 27. Adjusting slot; 28. Spring swing arm; 29. ​​Pressing plate; 30. Second tension spring; 31. Micro motor; 32. Extension plate; 33. First push rod; 34. Tube clamp; 35. Second push rod. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] In the description of the invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the first embodiment of the invention, as Figure 1As shown, a composite tube flue gas diversion type anti-corrosion air preheater and its cleaning device include a shell 1 and tube boxes 2 for sealing the two ends of the shell 1. The tube boxes 2 are connected to the shell 1 by tube plates 3. One side of the tube boxes 2 located at the two ends of the shell 1 is the air side and the other side is the sealed side. The tube boxes 2 on the air side are separated by extension plates 32. One end of the extension plate 32 is connected to the inner wall of the air side tube box 2, and the other end is fixedly connected to the tube bundle 4. The tube bundle 4 is loaded in the shell 1. The tube bundle 4 is composed of multiple bundle plates and multiple heat exchange tubes 5.

[0023] In the above technical solution: the shell 1, the tube box 2 and the heat exchange tube 5 are made of the same material. The heat exchange tube is composed of an outer layer of stainless steel, a middle layer of flexible heat-conducting layer and an inner layer of carbon steel. The outer layer material can be made of different stainless steels according to the customer's situation. 316L stainless steel is selected for the outer layer. The corrosion resistance of 316L stainless steel is combined with carbon steel to form a heat-conducting composite tube. Flexible heat-conducting material is added between the two composite materials to improve the thermal conductivity of the composite material and solve the contact thermal resistance problem between the two materials.

[0024] In the implementation, the provided appendix Figure 1 For reference, the left side of the housing 1 is the air side. The air-side pipe box 2 is divided into an air inlet side and an air outlet side by an extension plate 32. The upper left side of the housing 1 has a flue gas inlet side, and the lower right side of the housing 1 has a flue gas outlet side.

[0025] High-temperature flue gas enters the shell 1 from the flue gas inlet side on the left side of the shell 1. As the flue gas volume increases, it is discharged from the flue gas outlet side on the lower right side of the shell 1. During this process, it exchanges heat with the heat exchange tube 5. Room temperature air enters the tube box 2 from the air inlet side and is blocked by the extension plate 32 before entering the lower heat exchange tube 5 and flowing to the closed tube box 2. The air entering the closed tube box 2 enters the heat exchange tube 5 at the upper part of the shell 1 and flows back to the air outlet side for use. The air is heated during the flow in the heat exchange tube 5.

[0026] The bundle plate includes at least a first bundle plate 6 and a second bundle plate 7, wherein multiple vertical baffle rods 8 are installed in the middle of the first bundle plate 6, and multiple horizontal baffle rods 9 are installed in the middle of the second bundle plate 7. Multiple sets of the first bundle plate 6 and the second bundle plate 7 are arranged alternately in the shell 1. The heat exchange tube 5 is inserted into the second mounting groove 11 between the multiple horizontal baffle rods 9 along the first mounting groove 10 between adjacent vertical baffle rods 8. The ends of the heat exchange tube 5 that are far apart from each other are inserted into the tube sheet 3.

[0027] In the above technical solution: the vertical deflector 8 of the first bundle plate 6 and the transverse deflector 9 of the second bundle plate 7, each first bundle plate 6 or second bundle plate 7 and the adjacent first bundle plate 6 or second bundle plate 7 form a flow zone. After the flue gas enters the first flow zone from the flue gas inlet side of the shell 1, the light flue gas is longitudinally split at the vertical deflector 8, and after entering the second flow zone, the flue gas is forced to be transversely flushed at the transverse deflector 9.

[0028] A cleaning device is placed inside the heat exchange tube 5 to remove scale buildup on the inner wall of the heat exchange tube 5.

[0029] The dust removal device includes a first sealing plate 12 and a second sealing plate 13. A rotating shaft 14 is installed between the first sealing plate 12 and the second sealing plate 13. The rotating shaft 14 is driven by a micro motor 31. A scraping component is installed on the rotating shaft 14.

[0030] In the above scheme, the micro motor 31 adopts an explosion-proof remote programmable motor, and the power supply of the micro motor 31 adopts thread power supply. A push rod for pushing the dust removal device into the heat exchange tube 5 is also installed on the first sealing plate 12. The push rod includes at least a first push rod 33 and a second push rod 35. The adjacent first push rod 33 and second push rod 35 are fixedly connected by pipe clamps 34. The multi-segment push rod can be connected as needed.

[0031] The scraping assembly includes a first fixed ring 15, a sliding ring 16, and a second fixed ring 17. The first fixed ring 15 and the second fixed ring 17 are mounted on a rotating shaft 14. The first fixed ring 15 is hinged to a first swing rod 18, and the second fixed ring 17 is hinged to a second swing rod 19. The other ends of the first swing rod 18 and the second swing rod 19 are rotatably connected to a mounting base 20. A flexible brush 21 is mounted on the mounting base 20. The flexible brush 21 is a nylon brush, a wire brush, or a spring scraper, selected according to the material of the heat exchange tube 5. A sliding ring 16 is also mounted on the rotating shaft 14. A third swing rod 22 is hinged to the sliding ring 16. The other end of the third swing rod 22 is hinged to the mounting base 20. A first tension spring 23 is sleeved on the rotating shaft 14 between the sliding ring 16 and the first fixed ring 15 or the second fixed ring 17. One end of the first tension spring 23 is connected to the sliding ring 16, and the other end of the first tension spring 23 is connected to the first fixed ring 15 or the second fixed ring 17.

[0032] By adopting the above technical solution: a seal is installed on the contact surface between the first sealing plate 12 and the second sealing plate 13 and the inner wall of the housing 1. The sealing form is a movable seal, and a sealing ring can be selected. In the initial state, the first tension spring 23 is in a contracted state, so the sliding ring 16 is close to the second fixed ring 17. At the same time, when the sliding ring 16 is close to the second fixed ring 17, the third swing rod 22 is at the maximum outward swing angle. At this time, the mounting seat 20 is at the highest position, which is slightly higher than the first sealing plate 12 and the second sealing plate 13.

[0033] During the maintenance and cleaning of the heat exchange tube 5, the staff removes the tube boxes 2 on both sides of the shell 1. After removal, the staff holds the cleaning device and presses the mounting base 20 and the wire brush to make the first swing rod 18, the second swing rod 19 and the third swing rod 22 swing. During the swing of the third swing rod 22, the sliding ring 16 overcomes the resistance of the first tension spring 23 and slides on the rotating shaft 14, so that the cleaning device is inserted into the heat exchange tube 5. When there is no external force, the first tension spring 23 pulls the sliding ring 16 to slide on the rotating shaft 14 during the reset process. During the movement of the sliding ring 16, the first swing rod 18, the second swing rod 19 and the third swing rod 22 swing, which makes the mounting base 20 and the wire brush rise, so that the wire brush is always in contact with the inner wall of the heat exchange tube 5. The micro motor 31 is started to drive the rotating shaft 14 to rotate, which drives the first fixed ring 15, the second fixed ring 17 and the sliding ring 16 to rotate, so that the wire brush rotates to scrape off the floating dust on the inner wall of the heat exchange tube 5.

[0034] It should be noted that the above scheme is only used for routine cleaning of heat exchange tube 5, for brushing the structure of the inner wall of heat exchange tube 5 and removing floating dust. It cannot be used for cleaning sticky materials. During the cleaning process, the flexible clamping method of the first tension spring is used to compensate for the change in inner diameter caused by the local structure.

[0035] Example 2:

[0036] A composite tube flue gas diversion type anti-corrosion air preheater and its cleaning device, comprising a shell 1 and a tube box 2 for sealing the two ends of the shell 1, wherein the tube box 2 is connected to the shell 1 by a tube plate 3, characterized in that a tube bundle 4 is loaded inside the shell 1, the tube bundle 4 being composed of multiple bundle plates and multiple heat exchange tubes 5.

[0037] In the above technical solution: the shell 1, the tube box 2 and the heat exchange tube 5 are made of the same material. The heat exchange tube is composed of an outer layer of stainless steel, a middle layer of flexible heat-conducting layer and an inner layer of carbon steel. The outer layer material can be made of different stainless steels according to the customer's situation. 316L stainless steel is selected for the outer layer. The corrosion resistance of 316L stainless steel is combined with carbon steel to form a heat-conducting composite tube. Flexible heat-conducting material is added between the two composite materials to improve the thermal conductivity of the composite material and solve the contact thermal resistance problem between the two materials.

[0038] In the implementation, the provided appendix Figure 1 For reference, the left side of the housing 1 is the air side. The air-side pipe box 2 is divided into an air inlet side and an air outlet side by an extension plate 32. The upper left side of the housing 1 has a flue gas inlet side, and the lower right side of the housing 1 has a flue gas outlet side.

[0039] High-temperature flue gas enters the shell 1 from the flue gas inlet side on the left side of the shell 1. As the flue gas volume increases, it is discharged from the flue gas outlet side on the lower right side of the shell 1. During this process, it exchanges heat with the heat exchange tube 5. Room temperature air enters the tube box 2 from the air inlet side and is blocked by the extension plate before entering the lower heat exchange tube 5 and flowing to the closed tube box 2. The air entering the closed tube box 2 enters the heat exchange tube 5 at the upper part of the shell 1 and flows back to the air outlet side for discharge. The air is heated during the flow in the heat exchange tube 5.

[0040] The bundle plate includes at least a first bundle plate 6 and a second bundle plate 7, wherein multiple vertical baffle rods 8 are installed in the middle of the first bundle plate 6, and multiple horizontal baffle rods 9 are installed in the middle of the second bundle plate 7. Multiple sets of the first bundle plate 6 and the second bundle plate 7 are arranged alternately in the shell 1. The heat exchange tube 5 is inserted into the second mounting groove 11 between the multiple horizontal baffle rods 9 along the first mounting groove 10 between adjacent vertical baffle rods 8. The ends of the heat exchange tube 5 that are far apart from each other are inserted into the tube sheet 3.

[0041] A cleaning device is placed inside the heat exchange tube 5 to remove scale buildup on the inner wall of the heat exchange tube 5.

[0042] The dust removal device includes a first sealing plate 12 and a second sealing plate 13, a rotating shaft 14 is installed between the first sealing plate 12 and the second sealing plate 13, and a scraping component is installed on the rotating shaft 14.

[0043] In the above scheme, the micro motor 31 adopts an explosion-proof remote programmable motor, and the power supply of the micro motor 31 adopts thread power supply. A push rod for pushing the dust removal device into the heat exchange tube 5 is also installed on the first sealing plate 12. The push rod includes at least a first push rod 33 and a second push rod 35. The adjacent first push rod 33 and second push rod 35 are fixedly connected by pipe clamps 34. The multi-segment push rod can be connected as needed.

[0044] The scraping assembly includes a connecting rod 24 and an adjusting seat 25 connected to the connecting rod 24. The adjusting seat 25 has an adjusting groove 27 for mounting a brush 26. The brush 26 slides in the adjusting groove 27 and cannot be completely disengaged from the adjusting groove 27. This can be achieved by using a stepped adjusting groove 27 with a matching brush 26. A spring swing arm 28 is rotatably connected to the adjusting seat 25. The spring swing arm 28 is connected to a pressure plate 29, which contacts the bottom of the brush 26. A second tension spring 30 is fixedly mounted on the adjusting seat 25, and the other end of the second tension spring 30 is fixedly connected to the spring swing arm 28.

[0045] By adopting the above technical solution, a seal is installed on the contact surface between the first sealing plate 12 and the second sealing plate 13 and the inner wall of the housing 1. The sealing form is a movable seal, and a sealing ring can be selected.

[0046] During the maintenance and cleaning of heat exchange tube 5, the staff removes the tube boxes 2 on both sides of the shell 1. After removal, the staff holds the cleaning device and presses the brush 26 to adjust the height before inserting it into the heat exchange tube 5. When the brush 26 is pressed, the brush 26 is subjected to force on the clamping plate 29. The clamping plate 29 is subjected to force, which causes the spring swing arm 28 to swing against the resistance of the second tension spring 30. When there is no external force, the second tension spring 30 returns to its original position, so that the clamping plate 29 does work on the brush 26, thereby ensuring that the brush 26 is always in contact with the inner wall of the heat exchange tube 5.

[0047] It should be noted that the above solution is only used for routine cleaning of the heat exchange tubes, for brushing the structure of the inner wall of the heat exchange tubes and removing floating dust. It cannot be used for cleaning sticky materials. During the cleaning process, the flexible clamping method of the second tension spring is used to compensate for the change in inner diameter caused by the local structure.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A composite tube flue gas diversion type corrosion-resistant air preheater, comprising a shell (1) and tube boxes (2) for sealing both ends of the shell (1), the tube boxes (2) are connected to the shell (1) by a tube sheet (3), one side of the tube boxes (2) located at both ends of the shell (1) is the air side, and the other end is the sealed side, the air side tube box (2) is separated by an extension plate (32), one end of the extension plate (32) is connected to the inner wall of the air side tube box (2), and the other end is fixedly connected to the tube bundle (4), characterized in that, A tube bundle (4) is loaded inside the shell (1), the tube bundle (4) consisting of multiple bundle plates and multiple heat exchange tubes (5); The bundle plate includes at least a first bundle plate (6) and a second bundle plate (7), wherein multiple vertical baffle rods (8) are installed in the middle of the first bundle plate (6), and multiple horizontal baffle rods (9) are installed in the middle of the second bundle plate (7). Multiple sets of the first bundle plate (6) and the second bundle plate (7) are arranged alternately inside the shell (1). The heat exchange tubes (5) are inserted into the second mounting grooves (11) between the multiple horizontal baffle rods (9) along the first mounting grooves (10) between adjacent vertical baffle rods (8). The ends of the heat exchange tubes (5) that are far apart from each other are inserted into the tube sheet (3). The cleaning device is placed inside the heat exchange tube (5) and is used to remove scale from the inner wall of the heat exchange tube (5). The cleaning device includes a first sealing plate (12) and a second sealing plate (13). A rotating shaft (14) is installed between the first sealing plate (12) and the second sealing plate (13). The rotating shaft (14) is driven by a micro motor (31). A scraping component is installed on the rotating shaft (14). The scraping assembly includes a first fixed ring (15), a sliding ring (16), and a second fixed ring (17). The first fixed ring (15) and the second fixed ring (17) are mounted on a rotating shaft (14). The first fixed ring (15) is hinged to a first swing rod (18), and the second fixed ring (17) is hinged to a second swing rod (19). The other ends of the first swing rod (18) and the second swing rod (19) are rotatably connected to a mounting base (20). A flexible brush (21) is mounted on the mounting base (20). A sliding ring (16) is also installed on the rotating shaft (14). A third swing rod (22) is hinged on the sliding ring (16). The other end of the third swing rod (22) is hinged to the mounting base (20). A first tension spring (23) is sleeved on the rotating shaft (14) between the sliding ring (16) and the first fixed ring (15) or the second fixed ring (17). One end of the first tension spring (23) is connected to the sliding ring (16), and the other end of the first tension spring (23) is connected to the first fixed ring (15) or the second fixed ring (17). The scraping assembly also includes a connecting rod (24) and an adjusting seat (25) connected to the connecting rod (24). The adjusting seat (25) has an adjusting groove (27) for mounting the brush (26). A spring swing arm (28) is rotatably connected to the adjusting seat (25). The spring swing arm (28) is connected to a pressure plate (29). The pressure plate (29) contacts the bottom of the brush (26). A second tension spring (30) is fixedly installed on the adjusting seat (25). The other end of the second tension spring (30) is fixedly connected to the spring swing arm (28).

2. The composite tube flue gas diversion type corrosion-resistant air preheater according to claim 1, characterized in that: The flexible brush (21) can be a nylon brush, a wire brush, or a spring scraper, depending on the material of the heat exchange tube (5).

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