Leakage-proof adjusting device of air preheater

Abstract

The invention provides a leakproof adjusting device of an air preheater, and belongs to the field of sealing adjustment of air preheaters. The problems that under the dynamic working condition of the rotary air preheater, a traditional sector plate sealing adjusting system causes sealing failure and leakage aggravation due to mechanical movement are solved. Comprising a metal expansion joint, a truss bottom plate, a connecting sector plate suspender, a sealing assembly and a dustproof assembly. Through holes are formed in the surface of the truss bottom plate; a dustproof assembly is arranged in the metal expansion joint; the top of the dustproof assembly is connected with the lower surface of the truss bottom plate. The connecting sector plate suspender sequentially penetrates through the sealing assembly, the through hole of the truss bottom plate and the dustproof assembly from top to bottom. One end of the fan-shaped plate connecting suspender is connected with the fan-shaped plate, and the other end is provided with threads and screwed with an adjusting nut; the sealing assembly is arranged on the upper surface of the truss bottom plate; a transition plate is arranged at the lower end of the metal expansion joint. The sealing device is mainly used for maintaining the sealing performance of the sector plate of the rotary air preheater under the dynamic working condition.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealing adjustment system of rotary air preheater, in particular to an air preheater anti-leakage adjustment device. BACKGROUND

[0002] The preheater is one of the important auxiliary machines of the power station boiler, which mainly recovers the heat of the flue gas leaving the steam-water heat absorption section of the boiler, heats the combustion air, and reduces the exhaust gas temperature. The preheater is a large rotary equipment, which rotates the heat exchange fins by the rotor to carry out rotary heat exchange. The flue gas channel and the air channel of the preheater are separated by sector plates, which are fixed on the cold and hot end trusses of the preheater by adjustment devices. During the unit maintenance and operation, the gap between the sector plate and the rotor sealing piece is adjusted by rotating the adjustment nut on the adjustment device. The sector plate is located between the flue gas and the air, one side of which is the negative pressure flue gas, and the other side is the positive pressure air required for combustion. The existing adjustment device is sealed by sealing material, and the sealing material is asbestos rope, which is compressed by a gland. During the operation of the preheater, due to the pressure difference of the flue gas and the air on both sides of the sector plate, the positive pressure air will leak to the negative pressure flue gas side and the outside of the shell. When adjusting the adjustment nut, the adjustment hanger will move up and down, and the threads on the hanger will cause the asbestos rope to displace, resulting in the failure of the asbestos rope to be compressed tightly, the formation of a narrow gap between the asbestos rope and the gland, the failure of the asbestos rope to seal, and the leakage of the positive pressure air carrying dust through the narrow gap. With the increase of time, the leakage of the carried dust aggravates the abrasion of the asbestos rope, resulting in the aggravation of the outward leakage. During the cleaning of the preheater, part of the water will flow into the adjustment device through the opening position of the adjustment device hanger, and after mixing with the accumulated dust, it will form a hard block, resulting in the difficulty of adjustment of the adjustment device. SUMMARY

[0003] Therefore, the present application aims to provide an air preheater anti-leakage adjustment device to solve the problem of seal failure and leakage aggravation caused by mechanical movement of the traditional sector plate sealing adjustment system under dynamic working conditions.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: an air preheater anti-leakage adjustment device, comprising a metal expansion joint, a truss bottom plate, a connecting sector plate hanger, a sealing assembly and a dustproof assembly; the surface of the truss bottom plate is provided with a through hole; the metal expansion joint is internally provided with a dustproof assembly; the top of the dustproof assembly is connected with the lower surface of the truss bottom plate; the connecting sector plate hanger penetrates the sealing assembly, the through hole of the truss bottom plate and the dustproof assembly from top to bottom in sequence; one end of the connecting sector plate hanger is connected with the sector plate, and the other end is provided with threads and screwed with an adjustment nut; the sealing assembly is arranged on the upper surface of the truss bottom plate; the lower end of the metal expansion joint is provided with a transition plate.

[0005] Further, the sealing assembly comprises a water baffle and a waterproof slope coaxially sleeved with the connecting fan-shaped plate suspender, the waterproof slope is attached to the upper surface of the truss bottom plate, the outer diameter of the water baffle is larger than that of the waterproof slope, and the outer diameter of the waterproof slope is larger than that of the through hole on the surface of the truss bottom plate.

[0006] Further, the outer side of the water baffle and the waterproof slope is designed with a slope.

[0007] Further, the dustproof assembly comprises a dustproof gland and a gland spring, the dustproof gland is provided with through holes at equal intervals in the circumferential direction, studs are arranged in the through holes, one end of the stud is fixedly connected with the lower surface of the truss bottom plate, and the other end is threadedly connected with a nut, and the gland spring is sleeved with the outer side of the stud and located between the nut and the dustproof gland.

[0008] Further, a gasket is further sleeved on the stud and located between the gland spring and the dustproof gland.

[0009] Further, the diameter of the through hole on the dustproof gland is larger than that of the stud.

[0010] Further, a compressed air pipeline is arranged on the transition plate and communicates with the inside of the metal expansion joint.

[0011] Further, the support plate, the upper pressing plate and the lower pressing plate are further arranged, the upper pressing plate is connected with the lower surface of the truss bottom plate through the support plate, the upper pressing plate and the lower pressing plate are connected through bolts, through holes are arranged on the upper pressing plate and the lower pressing plate, the connecting fan-shaped plate suspender bottom sequentially penetrates the through holes of the upper pressing plate and the lower pressing plate, and the adjusting nut is located between the upper pressing plate and the lower pressing plate.

[0012] Further, the support plate is made of steel.

[0013] Further, the support plate is two, and the two support plates are symmetrically and interval arranged, and the distance between the two support plates is larger than the diameter of the metal expansion joint.

[0014] Compared with the prior art, the present application has the following beneficial effects: 1. The metal expansion joint is used as a core sealing element, the flexible bellows structure of the metal expansion joint can effectively compensate the displacement generated by the up-down adjustment of the fan-shaped plate suspender and the thermal expansion in the equipment operation, the top of the metal expansion joint is connected and sealed with the truss bottom plate through the dustproof assembly, the bottom is sealed through the transition plate, a complete sealed space is formed, the channel for the positive pressure air carrying dust to leak outward is blocked, the problem of sealing loosening caused by mechanical movement is avoided, and the sealing reliability and durability are significantly improved. 2、The dustproof assembly is arranged in the metal expansion joint, the dustproof assembly is always closely attached to the truss bottom plate through the continuous pressure of the gland spring in the dustproof assembly, a dynamic sealing barrier is formed, even if the connecting fan-shaped plate suspender is slightly inclined in the adjusting process, the dustproof gland can be self-adaptively adjusted in position under the action of the gland spring and the gasket, the sealing effect is continuously exerted, external dust is effectively prevented from entering the metal expansion joint, the accumulation of dust is avoided, and the smoothness of the adjusting action is ensured; 3、The compressed air pipeline is arranged at the bottom of the metal expansion joint, the compressed air introduced in the metal expansion joint forms a micro-positive pressure environment, so that the external dust-containing airflow is prevented from invading, and the inside is further swept, and the risk of failure caused by dust accumulation is further reduced; 4、The sealing assembly is arranged above the truss bottom plate, the waterproof slope in the sealing assembly can guide the splashed water flow to the surrounding, the water flow is prevented from accumulating around the connecting fan-shaped plate suspender, the water baffle arranged outside the waterproof slope can prevent the water flow from infiltrating along the surface of the connecting fan-shaped plate suspender, the phenomenon that the water is in contact with the dust in the adjusting device and is hardened is effectively avoided, and the long-term stability of the adjusting function is ensured; 5、The support pipe structure of the existing adjusting device is optimized to be a support plate made of steel, and sufficient operation space is reserved for the installation and welding of the metal expansion joint, so that the rigidity and stability of the support are enhanced, and the on-site installation and maintenance and replacement are facilitated, meanwhile, the locking mechanism of the upper pressing plate and the lower pressing plate cooperates with the support plate, the loosening of the adjusting nut in the equipment is effectively inhibited, the long-term maintenance of the gap between the fan-shaped plates after setting is ensured, and the stability of the entire sealing system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] The drawings constituting a part of the present application are used to provide further understanding of the present application, the schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings: Figure 1 It is a shaft side structure schematic view of the air preheater anti-leakage adjusting device described in the present application; Figure 2 It is Figure 1 A partial enlarged view in the middle A; Figure 3 It is an exploded structural schematic view of the air preheater anti-leakage adjusting device described in the present application; Figure 4 It is Figure 3 A partial enlarged view in the middle B.

[0016] In the drawings: 1, metal expansion joint; 2, truss bottom plate; 3, connecting sector plate suspender; 4, water baffle; 5, waterproof slope; 6, support plate; 7, compressed air pipeline; 8, upper pressing plate; 9, lower pressing plate; 10, adjusting nut; 11, transition plate; 12, dustproof gland; 13, gland spring. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0018] DETAILED DESCRIPTION: see Figures 1-4 In order to illustrate the present embodiment, an air preheater anti-leakage adjusting device is provided, which comprises a metal expansion joint 1, a truss bottom plate 2, a connecting sector plate suspender 3, a sealing assembly and a dustproof assembly. The truss bottom plate 2 is provided with through holes on the surface, and the truss bottom plate 2 serves as the mounting base and force bearing structure of the whole device, and the through holes provide a passage for the up-down movement of the connecting sector plate suspender 3. The metal expansion joint 1 is hollow and adopts a flexible bellows structure, and the metal expansion joint 1 is internally provided with the dustproof assembly. The metal expansion joint 1 is used for compensating thermal displacement and mechanical vibration. The dustproof assembly is connected to the lower surface of the truss bottom plate 2 at the top, and is used for blocking the external dust from entering the inside of the metal expansion joint. The connecting sector plate suspender 3 penetrates the sealing assembly, the through hole of the truss bottom plate 2 and the dustproof assembly in sequence from top to bottom. One end of the connecting sector plate suspender 3 is connected to a sector plate, and the other end is provided with a thread and screwed with an adjusting nut 10. The adjusting nut 10 is used for adjusting the radial gap between the sector plate and the rotor sealing piece. By rotating the adjusting nut 10 clockwise or counterclockwise, the connecting sector plate suspender 3 connected thereto is driven to move up and down along the axial direction by the transmission action of the thread, and the up-down movement of the connecting sector plate suspender 3 is directly transmitted to the sector plate connected at the top of the connecting sector plate suspender 3, so as to change the distance between the sector plate and the rotor sealing piece, and further control the air leakage rate of the air preheater at a lower level. The sealing assembly is arranged on the upper surface of the truss bottom plate 2, and is used for preventing the leaked liquid from penetrating into the inside of the metal expansion joint 1 below through the through hole on the truss bottom plate 2 and contacting with the dust to cause the phenomenon of hardening. The lower end of the metal expansion joint 1 is provided with a transition plate 11, which is used for connecting a transition member and realizing the sealing of the bottom of the metal expansion joint 1.

[0019] The metal expansion joint 1 is designed, and the stretching and compression characteristics of the metal expansion joint 1 can meet the up-down adjustment displacement requirement of the connecting fan-shaped plate suspender 3, and the adjustment function of the connecting fan-shaped plate suspender 3 is realized. Meanwhile, the dustproof assembly can prevent external dust from entering, the sealing assembly can prevent liquid leakage from penetrating into the metal expansion joint 1 to avoid dust caking, and the transition plate 11 realizes the bottom sealing of the metal expansion joint 1, thereby completely solving the problem of sealing failure of the asbestos rope in the prior art when the connecting fan-shaped plate suspender 3 is adjusted to move up and down. The metal expansion joint 1 has good wear resistance, can increase the service life of the adjusting device, and ensures stable operation of the equipment, reduces air leakage, and prevents component pollution.

[0020] The sealing assembly comprises a water baffle 4 and a waterproof slope 5 coaxially sleeved on the connecting fan-shaped plate suspender 3. The waterproof slope 5 is attached to the upper surface of the truss bottom plate 2. The outer diameter of the water baffle 4 is greater than that of the waterproof slope 5. The outer diameter of the waterproof slope is greater than that of the through hole on the surface of the truss bottom plate 2. The water baffle 4 is used to prevent water from flowing into the inside of the adjusting device along the connecting fan-shaped plate suspender 3. The height of the waterproof slope 5 is higher than that of the truss bottom plate 2, so that water flows out to a low position along the waterproof slope 5. When there is accumulated water, the water can be normally discharged to the outside of the waterproof slope 5 along the water baffle 4. The accumulated water cannot penetrate into the connecting fan-shaped plate suspender 3 and the inside of the adjusting device. The installation height of the water baffle 4 should be comprehensively considered according to the adjustment displacement requirement of the connecting fan-shaped plate suspender 3.

[0021] The outer side of the water baffle 4 and the waterproof slope 5 is designed with a slope. The slope design can guide the flow of liquid and prevent liquid accumulation.

[0022] The dustproof assembly comprises a dustproof gland 12 and a gland spring 13. The dustproof gland 12 is provided with through holes at equal intervals in the circumferential direction. Studs are arranged in the through holes. One end of the stud is fixedly connected to the lower surface of the truss bottom plate 2, and the other end is threadedly connected with a nut. The gland spring 13 is sleeved outside the stud and located between the nut and the dustproof gland 12. The stud is welded on the truss bottom plate 2. The dustproof gland 12 is compressed by the axial pressure of the nut. The stress of the dustproof gland is transmitted to the gland spring 13. The gland spring 13 is deformed, thereby compressing the dustproof gland 12. During the up-down adjustment of the connecting fan-shaped plate suspender 3, the gland spring 13 is always in a compressed state, thereby ensuring that the dustproof gland 12 is always in a sealed state and achieving continuous compression.

[0023] A gasket is further sleeved on the stud. The gasket is located between the gland spring 13 and the dustproof gland 12. By arranging the gasket, the end of the gland spring 13 is prevented from directly contacting and rubbing against the surface of the dustproof gland 12, and a flat and smooth contact surface is provided, so that the force of the gland spring 13 can be applied vertically and uniformly on the dustproof gland 12, which helps to keep the dustproof gland 12 balanced and avoids tilting due to uneven stress.

[0024] The through hole diameter of the dustproof gland 12 is larger than the stud diameter, so that the dustproof gland 12 has a certain radial adjustment capacity, and when the connecting fan-shaped plate suspender 3 is angularly inclined, the dustproof gland 12 can automatically adjust with the connecting fan-shaped plate suspender 3, so as to realize dynamic following and continuous pressing of the dustproof gland 12.

[0025] The transition plate 11 is provided with a compressed air pipe 7, the compressed air pipe 7 is in communication with the inside of the metal expansion joint 1, the compressed air pipe 7 is welded with the transition plate 11, and the compressed air pipe 7 is used to introduce high-pressure compressed air, which can prevent low-pressure hot air from carrying dust to leak into the metal expansion joint 1.

[0026] Further comprising a support plate 6, an upper pressing plate 8 and a lower pressing plate 9, the upper pressing plate 8 is connected with the lower surface of the truss bottom plate 2 through the support plate 6, the upper pressing plate 8 and the lower pressing plate 9 are connected through bolts, the upper pressing plate 8 and the lower pressing plate 9 are both provided with through holes, the connecting fan-shaped plate suspender 3 bottom sequentially penetrates the through holes of the upper pressing plate 8 and the lower pressing plate 9, the adjusting nut 10 is located between the upper pressing plate 8 and the lower pressing plate 9, the support plate 6 is used to connect the upper pressing plate 8 and the lower pressing plate 9 on the truss bottom plate 2, and the adjusting nut 10 is fixed between the upper pressing plate 8 and the lower pressing plate 9, when the adjusting nut 10 is rotated, the connecting fan-shaped plate suspender 3 moves up and down.

[0027] The support plate 6 is made of steel, so as to ensure that the whole mechanism has very high rigidity and strength during operation.

[0028] The support plate 6 is two, two support plates 6 are symmetrically and interval arranged, the distance between the two support plates 6 is greater than the diameter of the metal expansion joint 1, the symmetric layout of the support plate 6 is to ensure that the force is balanced, and prevent the mechanism from being distorted or inclined due to one-sided support, and the spacing between the two support plates 6 is greater than the diameter of the metal expansion joint 1, so as to provide installation space for the metal expansion joint 1.

[0029] The specific embodiments of the above disclosed application are only used to help explain the application. The specific embodiments do not describe all the details, nor limit the application to the specific embodiments described. According to the content of the specification, many modifications and changes can be made. The specification selects and specifically describes these embodiments in order to better explain the principles and practical application of the application, so that those skilled in the art can well understand and utilize the application.

Claims

1. A leak-proof regulating device for an air preheater, characterized in that: The device includes a metal expansion joint (1), a truss base plate (2), a connecting fan-shaped plate hanger (3), a sealing assembly, and a dustproof assembly; the surface of the truss base plate (2) is provided with a through hole; the metal expansion joint (1) is provided with a dustproof assembly; the top of the dustproof assembly is connected to the lower surface of the truss base plate (2); the connecting fan-shaped plate hanger (3) passes through the sealing assembly, the through hole of the truss base plate (2), and the dustproof assembly from top to bottom; one end of the connecting fan-shaped plate hanger (3) is connected to the fan-shaped plate, and the other end is threaded and screwed with an adjusting nut (10); the sealing assembly is provided on the upper surface of the truss base plate (2); the lower end of the metal expansion joint (1) is provided with a transition plate (11).

2. The air preheater leak-proof regulating device according to claim 1, characterized in that: The sealing assembly includes a water-blocking cover (4) and a waterproof slope (5) coaxially sleeved on the connecting fan-shaped plate hanger (3). The waterproof slope (5) is in contact with the upper surface of the truss base plate (2). The outer diameter of the water-blocking cover (4) is larger than the outer diameter of the waterproof slope (5). The outer diameter of the waterproof slope is larger than the outer diameter of the through hole on the surface of the truss base plate (2).

3. The air preheater leak-proof regulating device according to claim 2, characterized in that: The outer perimeter of the water-blocking cover (4) and the waterproof slope (5) is designed with a slope.

4. The air preheater leak-proof regulating device according to claim 1, characterized in that: The dustproof assembly includes a dustproof cover (12) and a cover spring (13); the dustproof cover (12) has through holes at equal intervals along the circumferential direction, and studs are inserted in the through holes. One end of the stud is fixedly connected to the lower surface of the truss base plate (2), and the other end is threaded with a nut; the cover spring (13) is sleeved on the outside of the stud and is located between the nut and the dustproof cover (12).

5. The air preheater leak-proof regulating device according to claim 4, characterized in that: A washer is also fitted onto the stud, and the washer is located between the pressure cap spring (13) and the dust cover (12).

6. The air preheater leak-proof regulating device according to claim 4, characterized in that: The diameter of the through hole on the dustproof cover (12) is larger than the diameter of the stud.

7. The air preheater leak-proof regulating device according to claim 1, characterized in that: A compressed air pipe (7) is provided on the transition plate (11), and the compressed air pipe (7) is internally connected to the metal expansion joint (1).

8. The air preheater leak-proof regulating device according to claim 1, characterized in that: It also includes a support plate (6), an upper pressure plate (8) and a lower pressure plate (9). The upper pressure plate (8) is connected to the lower surface of the truss base plate (2) through the support plate (6). The upper pressure plate (8) and the lower pressure plate (9) are connected by bolts. Both the upper pressure plate (8) and the lower pressure plate (9) are provided with through holes. The bottom of the connecting fan-shaped plate hanger (3) passes through the through holes of the upper pressure plate (8) and the lower pressure plate (9) in sequence. The adjusting nut (10) is located between the upper pressure plate (8) and the lower pressure plate (9).

9. The air preheater leak-proof regulating device according to claim 8, characterized in that: The support plate (6) is made of steel.

10. The air preheater leak-proof regulating device according to claim 8, characterized in that: There are two support plates (6), which are symmetrically spaced apart, and the distance between the two support plates (6) is greater than the diameter of the metal expansion joint (1).

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