Air pre-heater sealing device

Abstract

The utility model relates to the technical field of air pre-heaters, in particular to an air pre-heater sealing device which comprises a shell and a movable plate, a fan-shaped sealing plate is fixedly installed at the bottom of the movable plate, an axial sealing plate is arranged at the middle end of the inner wall of the shell, and circumferential sealing plates are arranged at the top and the bottom of the axial sealing plate. A rotor located on the inner side of the circumferential sealing plate and the inner side of the axial sealing plate is arranged at the middle end of the inner cavity of the shell, and a sealing piece is arranged on the outer surface of the rotor. Through the effects of the supporting plate, the metal ceramic spraying page plate and the hinge structure, the device has the advantages of being good in sealing effect and high in energy utilization rate, and the problems that due to the fact that gaps exist between rigid sealing and the sector plate, air leakage inevitably exists, meanwhile, mushroom-shaped deformation of the rotor can increase the gaps of the sealing pieces, and the sealing effect is poor are solved. And the air leakage rate of the air pre-heater is further increased.

Description

Technical Field

[0001] This utility model relates to the field of air preheater technology, specifically to an air preheater sealing device. Background Technology

[0002] When the boiler is in the start-up process or operating at low load, the heat exchange of the air preheater rotor is relatively small, and the thermal deformation of the upper hot end and lower cold end of the rotor is less than when the boiler is under heavy load. This results in less severe "mushroom-shaped" deformation of the air preheater rotor. At this time, the radial air leakage at the fixed sealing plate at the bottom of the rotor and the axial air leakage at the rotor circumference are the main air leakages of the air preheater. As the boiler load and the heat exchange of the air preheater rotor increase, the "mushroom-shaped" deformation of the rotor intensifies. The radial air leakage gap at the fixed fan-shaped sealing plate at the bottom of the rotor and the axial air leakage gap at the rotor circumference decrease, and the air leakage at these two locations decreases. However, the radial air leakage gap at the movable fan-shaped sealing plate at the top of the rotor increases significantly, and the air leakage also increases considerably, becoming the main air leakage of the air preheater.

[0003] In large air preheaters, carry-over leakage refers to the leakage of air contained within the heated surfaces of the air preheater and carried to the flue gas side by the rotor's rotation. This is inherent to rotary air preheaters. The faster the rotor rotates, the greater the carry-over leakage. The higher the fill degree of the heated surfaces in the rotor, the smaller the carry-over leakage. This leakage is unavoidable, and the leakage rate it affects is generally 15-30%.

[0004] Direct air leakage is the main factor affecting the leakage rate of rotary air preheaters. In a three-compartment air preheater, the primary and secondary air flowing through it are under positive pressure, while the flue gas is under negative pressure. Furthermore, the rotary air preheater itself is a rotating machine, and there are always certain gaps between the moving and stationary parts. Although these gaps are sealed, they cannot be completely blocked. Thus, under the influence of this pressure difference, air will leak directly into the flue gas through these gaps. The amount of direct air leakage is directly proportional to the size of these gaps and the square root of the pressure difference between the two sides.

[0005] Of the direct air leakage, radial leakage at the hot end accounts for approximately 50%-70%, and this proportion increases with the diameter. In the 1980s, countries around the world adopted automatic tracking technology to address this issue. For air preheaters with a diameter of 10 meters or more, without hot-end sector plate tracking technology, the leakage rate is generally between 10% and 15%, severely impacting the overall boiler operation.

[0006] Currently, increased air leakage rate leads to increased air and flue gas flow, higher power consumption of forced draft fans and induced draft fans, resulting in insufficient fan output and affecting the overall unit output. It also causes insufficient oxygen in boiler combustion, increased heat loss from incomplete combustion and flue gas, and for every 19°C increase in flue gas temperature, boiler efficiency decreases by approximately 1%, resulting in an additional consumption of over 14,000 tons of standard coal annually. Increased air leakage rate in the air preheater also increases the amount of air leaking from the air side to the flue gas side, accelerates the flow rate, reduces the lifespan of easily worn parts, and correspondingly increases maintenance workload. Furthermore, increased flue gas flow and velocity at the air preheater outlet reduce the efficiency of the electrostatic precipitator. Simultaneously, all equipment downstream of the air preheater experiences increased wear, significantly increasing maintenance workload. Therefore, we propose an air preheater sealing device. Utility Model Content

[0007] The purpose of this invention is to provide an air preheater sealing device that has the advantages of good sealing effect and high energy utilization rate. It solves the problem that air leakage is inevitable due to the gap between the rigid seal and the sector plate, and that the mushroom-shaped deformation of the rotor will increase the gap of the sealing plate, further increasing the air leakage rate of the air preheater.

[0008] To achieve the above objectives, this utility model provides the following technical solution: an air preheater sealing device, comprising a housing and a movable plate, wherein a fan-shaped sealing plate is fixedly installed at the bottom of the movable plate, an axial sealing plate is provided at the middle of the inner wall of the housing, and circumferential sealing plates are provided at the top and bottom of the axial sealing plate. A rotor located inside the circumferential and axial sealing plates is provided at the middle of the inner cavity of the housing, and a sealing sheet is provided on the outer surface of the rotor. A support plate is fixedly installed on the top of the sealing sheet, and a fixed bearing plate is provided at the lower end of one side of the support plate. The inner surface of the plate has multiple equidistant through holes. The upper end of the support plate is provided with a hinge structure. The upper end of the support plate is movably connected to a metal-ceramic spray-coated leaf plate through the hinge structure. The bottom of the metal-ceramic spray-coated leaf plate is fixedly connected with multiple adjusting seats corresponding to the through holes. The inner side of the adjusting seat is provided with a hinge sleeve. The bottom of the hinge sleeve is fixedly connected with an adjusting rod that passes through the inner side of the through hole. The lower end of the outer surface of the adjusting rod, located at the bottom of the fixed support plate, is threaded with a locking nut. The upper end of the adjusting rod is provided with a special spring sleeved on its outer side.

[0009] Preferably, the metal-ceramic sprayed plate is a precision-machined cast steel part with a sprayed metal-ceramic coating, and the contact area between the metal-ceramic sprayed plate and the fan-shaped sealing plate is coated with a nano-alloy ceramic coating by triboelectric spraying.

[0010] Preferably, the material of the special spring is a nickel-based alloy.

[0011] Preferably, a connecting plate is provided on the top of the housing, and an adjustment hole is provided on the inner surface of one end of the connecting plate. An internal threaded sleeve is fixedly connected to the inner side of the adjustment hole, and an adjustment threaded rod is threadedly connected to the inner side of the internal threaded sleeve.

[0012] Preferably, a rotating block is fixedly connected to the top of the adjusting threaded rod, a ball head is provided at the bottom of the adjusting threaded rod, a ball seat is movably connected to the outer side of the ball head, and the movable plate is fixedly connected to the bottom of the ball seat.

[0013] Preferably, the top end of the movable plate away from the adjusting threaded rod is fixedly connected to a guide rod that slides on the inner surface of the connecting plate.

[0014] Preferably, there are multiple support plates, and the included angle between two adjacent support plates is equal.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. This utility model, by installing the support plate on top of the sealing plate, allows the metal-ceramic sprayed blade to move to the underside of the fan-shaped sealing plate when the rotor drives the sealing plate and support plate to rotate. With the assistance of the hinge structure, the metal-ceramic sprayed blade slides the lower end of the adjusting rod onto the inner surface of the through hole via the adjusting seat and hinge sleeve. This compresses the special spring, causing it to deform. When the metal-ceramic sprayed blade contacts the fan-shaped sealing plate, a tight, gapless sealing system is formed. This gives the device the advantages of good sealing effect and high energy utilization, making it convenient for users.

[0017] 2. When the rotating block drives the adjusting threaded rod to rotate within the internal threaded sleeve, it will cause the ball head to rotate within the ball seat. With the assistance of the internal threaded sleeve fixed in the adjusting hole and the guide rod, the position of the movable plate and the sector-shaped sealing plate can be adjusted. This makes it convenient to adjust the fitting height between the sector-shaped sealing plate and the metal-ceramic sprayed plate according to actual usage needs, thus facilitating user operation. Attached Figure Description

[0018] Figure 1 This is a first-view structural diagram of the present invention;

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of the present invention from a second perspective;

[0020] Figure 3 This is a schematic diagram of the exploded structure of this utility model;

[0021] Figure 4 This is a schematic diagram of the structure of this utility model.

[0022] In the diagram: 1. Housing; 2. Adjusting threaded rod; 3. Internal threaded sleeve; 4. Rotating block; 5. Guide rod; 6. Connecting plate; 7. Rotor; 8. Adjusting hole; 9. Ball head; 10. Ball seat; 11. Movable plate; 12. Sealing plate; 13. Axial sealing plate; 14. Circumferential sealing plate; 15. Support plate; 16. Through hole; 17. Locking nut; 18. Fixed bearing plate; 19. Adjusting rod; 20. Hinge structure; 21. Special spring; 22. Metal-ceramic coated leaf plate; 23. Adjusting seat; 24. Hinge sleeve; 25. Fan-shaped sealing plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] The components of this application, including the housing 1, adjusting threaded rod 2, internal threaded sleeve 3, rotating block 4, guide rod 5, connecting plate 6, rotor 7, adjusting hole 8, ball head 9, ball seat 10, movable plate 11, sealing plate 12, axial sealing plate 13, circumferential sealing plate 14, support plate 15, through hole 16, locking nut 17, fixed bearing plate 18, adjusting rod 19, hinge structure 20, special spring 21, metal-ceramic sprayed leaf plate 22, adjusting seat 23, hinge sleeve 24, and sector-shaped sealing plate 25, are all general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0027] Example 1

[0028] Please see Figures 1-4 As shown, this utility model provides a technical solution: an air preheater sealing device, including a housing 1 and a movable plate 11. A fan-shaped sealing plate 25 is fixedly installed at the bottom of the movable plate 11. An axial sealing plate 13 is provided at the middle of the inner wall of the housing 1. Circular sealing plates 14 are provided at the top and bottom of the axial sealing plate 13. A rotor 7 is provided at the middle of the inner cavity of the housing 1, located inside the circumferential sealing plate 14 and the axial sealing plate 13. A sealing sheet 12 is provided on the outer surface of the rotor 7. A support plate 15 is fixedly installed on the top of the sealing sheet 12. There are multiple support plates 15, and the included angle between two adjacent support plates 15 is equal. A fixed bearing plate 18 is provided at the lower end of one side of the support plate 15. Multiple equidistant through holes 16 are opened on the inner surface of the fixed bearing plate 18. A hinge is provided at the upper end of the support plate 15. Structure 20, the upper end of the support plate 15 is movably connected to a metal-ceramic sprayed plate 22 via a hinge structure 20. The metal-ceramic sprayed plate 22 is a precision-machined cast steel part with a metal-ceramic coating. The contact part between the metal-ceramic sprayed plate 22 and the fan-shaped sealing plate 25 is coated with a nano-alloy ceramic coating by triboelectric spraying. The bottom of the metal-ceramic sprayed plate 22 is fixedly connected to multiple adjusting seats 23 corresponding to the through holes 16. The inner side of the adjusting seat 23 is provided with a hinge sleeve 24. The bottom of the hinge sleeve 24 is fixedly connected to an adjusting rod 19 that passes through the inner side of the through hole 16. The lower end of the outer surface of the adjusting rod 19, located at the bottom of the fixed bearing plate 18, is threadedly connected to a locking nut 17. The upper end of the adjusting rod 19 is provided with a special spring 21 sleeved on its outer side. The material of the special spring 21 is a nickel-based alloy.

[0029] This technical solution involves installing the support plate 15 on top of the sealing plate 12. When the rotor 7 drives the sealing plate 12 and the support plate 15 to rotate, the metal-ceramic sprayed blade 22 moves to the bottom of the fan-shaped sealing plate 25. With the assistance of the hinge structure 20, the metal-ceramic sprayed blade 22, through the adjusting seat 23 and the hinge sleeve 24, drives the lower end of the adjusting rod 19 to slide on the inner surface of the through hole 16, thereby compressing the special spring 21 and causing it to deform. When the metal-ceramic sprayed blade 22 contacts the fan-shaped sealing plate 25, a tight and gapless sealing system is formed. When the metal-ceramic sprayed blade 22 separates from the fan-shaped sealing plate 25, the compressed special spring 21 will drive the metal-ceramic sprayed blade 22 to automatically spring up through the adjusting rod 19. This cycle repeats, giving the device the advantages of good sealing effect and high energy utilization, which is beneficial to people's use.

[0030] It should be noted that the sector-shaped sealing plate 25 at the upper end of the inner cavity of the housing 1 and fixed to the bottom of the movable plate 11 is a movable sector-shaped sealing plate, as shown in the figure, while the sector-shaped sealing plate 25 at the lower end of the inner cavity of the housing 1 and fixed to the bottom of the movable plate 11 is a fixed sector-shaped sealing plate, which is not shown in the prior art figures.

[0031] Example 2

[0032] Based on Embodiment 1, this utility model is as follows: Figures 1-4 As shown, a connecting plate 6 is provided on the top of the housing 1. An adjustment hole 8 is provided on the inner surface of one end of the connecting plate 6. An internal threaded sleeve 3 is fixedly connected to the inner side of the adjustment hole 8. An adjusting threaded rod 2 is threadedly connected to the inner side of the internal threaded sleeve 3. A rotating block 4 is fixedly connected to the top of the adjusting threaded rod 2. A ball head 9 is provided at the bottom of the adjusting threaded rod 2. A ball seat 10 is movably connected to the outer side of the ball head 9. A movable plate 11 is fixedly connected to the bottom of the ball seat 10. A guide rod 5 that slides on the inner surface of the connecting plate 6 is fixedly connected to the top end of the movable plate 11 away from the adjusting threaded rod 2.

[0033] This technical solution: When the rotating block 4 drives the adjusting threaded rod 2 to rotate within the internal threaded sleeve 3, it will drive the ball head 9 to rotate within the ball seat 10. With the assistance of the internal threaded sleeve 3 fixed in the adjusting hole 8 and the guide rod 5, the position of the movable plate 11 and the sector-shaped sealing plate 25 can be adjusted. This makes it convenient to adjust the mating height between the sector-shaped sealing plate 25 and the metal ceramic sprayed plate 22 according to actual usage requirements, thus facilitating user operation.

[0034] It should be noted that controlling air preheater leakage has always been an important project for energy conservation and emission reduction in power plants. Although traditional rigid seals for air preheaters can control the leakage rate to some extent, the effect is not significant. Rigid seals mainly require adjustment of the sealing plates when the unit is at 100% load. Once the load decreases, the leakage cannot be controlled, and the economic efficiency cannot be guaranteed. In contrast, flexible contact seals are gapless seals, and load changes do not have a significant impact on them. Therefore, they are more economical than traditional rigid seals.

[0035] As an alternative to this solution, some structural modifications can be made to the flexible sealing product. The metal-ceramic coated blade can be made entirely of wear-resistant alloy material, or it can be welded or inlaid onto the body as a single alloy strip. The connection between the spring and the slider can be achieved via an adjusting rod or directly via a fixed base. The hinge structure can be connected via a round tube and a pin, or via other methods. The bending angle at the connection between the support plate and the hinge structure can be 90° or other angles.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. An air preheater sealing device, comprising a housing (1) and a movable plate (11), characterized in that: A fan-shaped sealing plate (25) is fixedly installed at the bottom of the movable plate (11). An axial sealing plate (13) is provided at the middle of the inner wall of the housing (1). Circumferential sealing plates (14) are provided at the top and bottom of the axial sealing plate (13). A rotor (7) located inside the circumferential sealing plate (14) and the axial sealing plate (13) is provided at the middle of the inner cavity of the housing (1). A sealing plate (12) is provided on the outer surface of the rotor (7). A support plate (15) is fixedly installed on the top of the sealing plate (12). A fixed bearing plate (18) is provided at the lower end of one side of the support plate (15). A plurality of equidistant through holes (16) are opened on the inner surface of the fixed bearing plate (18). A hinge structure (20) is provided at the upper end of the plate (15). A metal ceramic spraying plate (22) is movably connected to the upper end of the support plate (15) through the hinge structure (20). A plurality of adjusting seats (23) corresponding to the through holes (16) are fixedly connected to the bottom of the metal ceramic spraying plate (22). A hinge sleeve (24) is provided on the inner side of the adjusting seat (23). An adjusting rod (19) passing through the inner side of the through hole (16) is fixedly connected to the bottom of the hinge sleeve (24). A locking nut (17) is threadedly connected to the lower end of the outer surface of the adjusting rod (19) and located at the bottom of the fixed bearing plate (18). A special spring (21) sleeved on the outer side of the adjusting rod (19) is provided at the upper end of the adjusting rod (19).

2. The air preheater sealing device according to claim 1, characterized in that: The metal-ceramic sprayed leaf plate (22) is a precision-machined cast steel part with a sprayed metal-ceramic coating, and the contact part between the metal-ceramic sprayed leaf plate (22) and the fan-shaped sealing plate (25) is coated with a nano-alloy ceramic coating by triboelectric spraying.

3. The air preheater sealing device according to claim 1, characterized in that: The special spring (21) is made of a nickel-based alloy.

4. The air preheater sealing device according to claim 1, characterized in that: The top of the housing (1) is provided with a connecting plate (6), and an adjustment hole (8) is provided on the inner surface of one end of the connecting plate (6). An internal threaded sleeve (3) is fixedly connected to the inner side of the adjustment hole (8), and an adjustment threaded rod (2) is threadedly connected to the inner side of the internal threaded sleeve (3).

5. The air preheater sealing device according to claim 4, characterized in that: The top of the adjusting threaded rod (2) is fixedly connected to a rotating block (4), and the bottom of the adjusting threaded rod (2) is provided with a ball head (9). The outer side of the ball head (9) is movably connected to a ball seat (10), and the movable plate (11) is fixedly connected to the bottom of the ball seat (10).

6. The air preheater sealing device according to claim 5, characterized in that: The top end of the movable plate (11) away from the adjusting threaded rod (2) is fixedly connected to a guide rod (5) that slides on the inner surface of the connecting plate (6).

7. The air preheater sealing device according to claim 1, characterized in that: The number of the support plates (15) is multiple, and the included angle between two adjacent support plates (15) is equal.

Images