A radial sealing device for a rotary air preheater

Abstract

A radial sealing device for a rotary air preheater includes: a fixed mounting plate connected to a radial partition of the rotor; a movable sealing plate pivotally connected to the fixed mounting plate, wherein the fixed mounting plate and the movable sealing plate are provided with positioning holes; a hinge seat located within the positioning holes, the hinge seat being fixedly connected to the fixed mounting plate and slidably connected to the movable sealing plate; a movable connecting rod rotatably connected to the hinge seat; a return spring sleeved on the movable connecting rod; and a limiting member connected to the end of the movable connecting rod, the limiting member causing the return spring to be in a compressed state. This application eliminates the need for a spring seat, simplifying the structure. The force on the return spring in this application is borne by the movable sealing plate and the limiting member. Compared to the force borne by the spring seat, the movable sealing plate and the limiting member are less prone to deformation and have a longer service life. When the movable sealing plate is compressed, it causes the return spring to compress, and the direction of the movable connecting rod changes accordingly, ensuring that the spring remains perpendicular to the spring center during compression.

Description

Technical Field

[0001] This application relates to the field of rotary air preheater technology, and more particularly to a radial sealing device for a rotary air preheater. Background Technology

[0002] Rotary air preheaters are important energy-saving devices for waste heat utilization in thermal power generation. A rotary air preheater consists of a rotor, heat storage elements, and a shell. The heat storage elements are located within the rotor, and the shell is divided into a flue gas zone, an air zone, and a sealed zone. The sealed zone separates the flue gas zone and the air zone by a sector plate. Heat exchange between the flue gas and air occurs during rotor rotation. Specifically, when the rotor rotates to the flue gas zone, heat in the flue gas is transferred to the heat storage elements; when the rotor rotates to the air zone, heat in the heat storage elements is transferred to the air. Thus, heat utilization is achieved by transferring heat from the flue gas to the air. The air leakage rate is one of the important indicators for evaluating the energy-saving effect of an air preheater. Reducing the air preheater leakage rate not only reduces the operating energy consumption of the primary air fan, secondary air fan, and induced draft fan, but also reduces heat loss caused by the loss of hot air from the primary and secondary air. Reducing air preheater leakage also reduces wind damage to the air preheater equipment to a certain extent. Furthermore, reducing air preheating leakage effectively reduces the oxygen content in the boiler tail flue gas, lowering the pollutant emission conversion factor.

[0003] The seals of rotary air preheaters include radial seals, circumferential seals, axial seals, and axial seals. Among them, the radial seal is relatively complex to control because the gap between the rotor and the housing changes in real time due to the relative motion between the rotor and the housing and the phenomenon of thermal expansion and contraction.

[0004] Currently, there are several technical methods for controlling the radial seal of air preheaters: 1. Fixed sealing plate type. This type is further divided into fixed sealing plate type and elastic fixed sealing plate type; 2. Contact type. The contact type mainly uses a return spring to gradually release the pre-compression of the sealing component in a cold state and then in a hot state to control the sealing gap; 3. Mechanical control adjustment type. Its main principle is to use sensors to measure the gap between the sealing plate and the sector plate, and adjust the rise and fall of the sector plate to control the sealing gap and reduce the leakage rate; 4. Thermal deformation compensation type seal. Its principle is based on the thermal deformation characteristics of the air preheater. The central part expands upwards after thermal deformation, and the rotor deflection is smaller after thermal deformation, while the outer circle has a larger deflection after thermal deformation. The sealing gap is compensated by the difference in deflection along the rotor diameter.

[0005] For contact-type sealing structures, the structure is generally as described in the scheme of application number 202021863163.X, entitled "Floating Sealing Device for Rotary Air Preheater": it includes a moving plate, a stationary plate, an elastic compression device, and a rotating connection device. The moving plate is composed of a vertical plate, a planar inclined plate, and a vertical inclined plate. A sleeve is fixed on the upper side wall of the vertical plate, and a sleeve is also provided on the upper side wall of the stationary plate. The sleeves on the vertical plate and the sleeves on the stationary plate are arranged alternately and connected together by a rotating shaft to form a rotating connection device. The elastic compression device includes a guide rod and a spring fitted on the guide rod. A spring pressure plate is provided at the upper end of the guide rod. The guide rod is connected to a fixed seat through a pin. A base is provided on the lower side wall of the stationary plate. A through hole is provided in the middle of the base, and the guide rod passes through the through hole of the base.

[0006] In the aforementioned sealing structure, the spring force is not entirely along the axial direction, making it prone to bending during compression, leading to uneven stress and shortening the spring's lifespan. Simultaneously, the spring seat is also at risk of deformation or breakage, resulting in seal failure. Utility Model Content

[0007] In view of this, this application proposes a radial sealing device for a rotary air preheater to improve the life of the spring and the reliability of the sealing device.

[0008] A radial sealing device for a rotary air preheater, comprising: A fixed mounting plate connected to the radial partition of the rotor; A movable sealing plate is pivotally connected to a fixed mounting plate, and both the fixed mounting plate and the movable sealing plate are provided with positioning holes; A hinge seat located in a positioning hole, the hinge seat being fixedly connected to a fixed mounting plate and slidably connected to a movable sealing plate; A movable link that is rotatably connected to the hinge seat; A return spring fitted onto the movable connecting rod; A limiting component connected to the end of the movable link compresses the return spring.

[0009] To ensure the secure connection between the hinge seat and the fixed mounting plate, the hinge seat is welded to the fixed mounting plate.

[0010] To ensure a compact reset structure, the reset spring is a disc spring.

[0011] For ease of installation and disassembly, the limiting component is a nut, and correspondingly, the end of the movable connecting rod is provided with an external thread, and the nut is threadedly connected to the movable connecting rod.

[0012] To improve the compressive strength of the nut, the movable connecting rod is also spot-welded to the nut.

[0013] Preferably, the movable sealing plate includes: A sealing part used to seal the gap between the rotor and the housing; Support parts stacked on the fixed mounting plate; The sealing part, the supporting part, and the pivot rod form a lever.

[0014] Compared with the radial sealing device of the existing rotary air preheater, the technical advantage of this application is that it eliminates the need for a spring seat, thus simplifying the structure.

[0015] In this application, the force on the return spring is distributed across the movable sealing plate and the limiting component. Compared to the force on the spring seat, the movable sealing plate and the limiting component are less prone to deformation and have a longer service life.

[0016] When the movable sealing plate is compressed, it drives the return spring to compress, and the direction of the movable connecting rod changes accordingly, ensuring that the spring is always perpendicular to the spring center during the compression process, so that the spring is subjected to uniform force and the service life of the spring is improved. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of a preferred angle of the radial sealing device for a rotary air preheater according to this application; Figure 2 This is a schematic diagram of another preferred angle of the radial sealing device for a rotary air preheater according to this application; Figure 3 This is a cross-sectional view of the radial sealing device for a rotary air preheater according to this application; Figure 4 This is a schematic diagram of the radial sealing device for a rotary air preheater without a return spring, as described in this application.

[0018] Figure 5 This is a schematic diagram of the radial sealing device for a rotary air preheater of this application mounted on the rotor diaphragm.

[0019] Figure 6 This is a schematic diagram of the radial sealing device for a rotary air preheater of this application installed on the rotor diaphragm at another angle.

[0020] Figure 7 for Figure 6 A partial structural diagram.

[0021] Explanation of reference numerals in the attached figures: Fixed mounting plate 1, positioning hole 11, movable sealing plate 2, sealing part 21, support part 22, hinge seat 3, movable connecting rod 4, return spring 5, limiting part 6, pivot 7, clamping plate 8, compensation plate 9, shift fork 91. Detailed Implementation

[0022] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0023] Please refer to Figures 1 to 4 A radial sealing device for a rotary air preheater, comprising: Fixed mounting plate 1 connected to the radial partition of the rotor; The rotor of the rotary air preheater includes a central shaft, radial diaphragms, tangential diaphragms, and heat storage elements. The radial diaphragms are radially distributed along the central shaft, dividing the rotor into several sector-shaped compartments, in which the heat storage elements are housed. The fixed mounting plate 1 of this application is fixed to the radial diaphragms, and the length of the fixed mounting plate 1 is the same as the length of the radial diaphragms. After the fixed mounting plate 1 is positioned, it can be welded or bolted together.

[0024] The movable sealing plate 2 is pivotally connected to the fixed mounting plate 1. The fixed mounting plate 1 and the movable sealing plate 2 are provided with positioning holes 11. The movable sealing plate 2 is an integral pressed structure. The shaft system installed at the hot end avoids damage from dust and smoke, which can provide good protection and improve service life.

[0025] Specifically, in a preferred embodiment, the end of the fixed mounting plate 1 is pivotally connected to the middle of the movable sealing plate 2, allowing the movable sealing plate 2 to rotate relative to the fixed mounting plate 1. More specifically, the fixed mounting plate 1 and the movable sealing plate 2 are provided with pin holes spaced apart, and a pin passes through the pin holes of the fixed mounting plate 1 and the movable sealing plate 2 to achieve pivot connection.

[0026] The hinge seat 3 is located in the positioning hole 11. The hinge seat 3 is fixedly connected to the fixed mounting plate 1 and slidably connected to the movable sealing plate 2. The positioning hole 11 is used to install the hinge seat 3, and the hinge seat 3 is fixed on the fixed mounting plate 1. The hinge seat 3 is also fitted into the positioning hole 11 of the movable sealing plate 2. When the movable sealing plate 2 rotates around the pivot 7, the hinge seat 3 and the movable sealing plate 2 slide relative to each other.

[0027] The movable link 4 is rotatably connected to the hinge seat 3; A return spring 5 is sleeved on the movable connecting rod 4; The limiting member 6 connected to the end of the movable link 4 keeps the return spring 5 in a compressed state.

[0028] During rotation, the movable sealing plate 2 causes the return spring 5 to compress or return to its original position. Since the hinge seat 3 is fixed to the fixed mounting plate 1 and is always perpendicular to it, the movable sealing plate 2 forms an angle with the fixed mounting plate 1 during rotation, thus preventing the hinge seat 3 from remaining perpendicular to the movable sealing plate 2. The return spring 5 is also in contact with the movable sealing plate 2. When the movable sealing plate 2 rotates, it causes the return spring 5 to rotate, which in turn causes the movable connecting rod 4 to rotate. This prevents the return spring 5 from bending during compression, ensuring even force distribution and extending its service life.

[0029] The hinge seat 3 and the positioning hole 11 of the fixed mounting plate 1 can be interference-fitted to fix the hinge seat 3 by static friction.

[0030] However, in order to ensure the firmness of the connection between the hinge seat 3 and the fixed mounting plate 1, in a preferred embodiment, the hinge seat 3 is also welded to the fixed mounting plate 1.

[0031] The movable mounting plate has a slight rotation relative to the hinge seat 3. In order to prevent the hinge seat 3 from interfering with the movable sealing plate 2, the size of the positioning hole 11 of the movable sealing plate 2 is larger than the size of the hinge seat 3.

[0032] The return spring 5 can be a common cylindrical spring, but for the sake of compact structure, the return spring 5 is a disc spring. On the other hand, the essential difference between a disc spring, i.e., a butterfly spring and a cylindrical spring is that the compression and force of a butterfly spring are non-linear, which can reduce the contact force between the sealing plate and the sector plate to a certain extent, thereby reducing wear.

[0033] For ease of installation and disassembly, the limiting component 6 is a nut, and correspondingly, the end of the movable connecting rod 4 is provided with an external thread, and the nut is threadedly connected to the movable connecting rod 4.

[0034] To improve the compressive strength of the nut, the movable connecting rod 4 is also spot-welded to the nut.

[0035] In a preferred embodiment, the movable sealing plate 2 includes: Sealing part 21 used to seal the gap between the rotor and the housing; Support 22 stacked on fixed mounting plate 1; The sealing part 21, the support part 22, and the pivot rod form a lever.

[0036] In a preferred embodiment, the sealing portion 21 and the support portion 22 form an obtuse angle. As the sealing portion 21 passes through the sector plate, the angle of the sector plate changes with the width of the gap, and the sealing portion 21 always remains in contact with the sector plate to maintain a sealed state.

[0037] In addition, this application can also be used for axial sealing of rotary air preheaters.

[0038] The radial sealing device for a rotary air preheater described in this application can be used in two ways. The first method is to weld the fixed mounting plate to the rotor's compartment plate. The second method is as follows: Figures 5-7 As shown, a fixed mounting plate 1 is sandwiched between a clamping plate 8 and a rotor partition. A compensation plate 9 is also installed on the other side of the partition, with a fork 91 passing through the partition and connecting to the fixed mounting plate 1. Thus, during hot operation, when the radial clearance at the hot end of the rotor increases and the clearance at the cold end decreases, forming a triangular leakage area, the compensation plate 9 causes the sealing device to tilt upwards, keeping the movable sealing plate 2 parallel to the preheater's fan-shaped plate, increasing the line contact length between the movable sealing plate 2 and the fan-shaped plate, thereby achieving radial sealing. In this situation, the rotor typically undergoes a mushroom-shaped deformation, resulting in a large gap in the leakage area. The sealing effect of the sealing part 21 of the movable sealing plate 2 alone is limited. By using the compensation plate 9 and lever action, the movable sealing plate 2 can be moved as a whole, achieving a better sealing effect.

[0039] In a preferred embodiment, the upper end of the clamping plate 8 complements the notch of the movable sealing plate 2, and the clamping plate 8 is fitted with the fixed mounting plate 1.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A radial seal arrangement for a rotary air preheater, characterized by include: Fixed mounting plate (1) connected to the radial partition of the rotor; A movable sealing plate (2) is pivotally connected to a fixed mounting plate (1), and the fixed mounting plate (1) and the movable sealing plate (2) are provided with positioning holes (11); A hinge seat (3) is located in the positioning hole (11), the hinge seat (3) is fixedly connected to the fixed mounting plate (1), and the hinge seat (3) is slidably connected to the movable sealing plate (2); The movable link (4) is rotatably connected to the hinge seat (3); A return spring (5) is sleeved on the movable connecting rod (4); The limiting member (6) connected to the end of the movable link (4) causes the return spring (5) to be in a compressed state.

2. A radial seal for a rotary air preheater as defined in claim 1 wherein: The hinge seat (3) is welded to the fixed mounting plate (1).

3. The radial seal for a rotary air preheater as set forth in claim 1, wherein: The reset spring (5) is a disc spring.

4. The radial seal for a rotary air preheater according to claim 1, wherein: The limiting component (6) is a nut, and correspondingly, the end of the movable connecting rod (4) is provided with an external thread, and the nut is threadedly connected to the movable connecting rod (4).

5. The radial seal for a rotary air preheater according to claim 4, wherein: The movable connecting rod (4) is also spot-welded to the nut.

6. A radial seal for a rotary air preheater as defined in claim 1 wherein: The movable sealing plate (2) includes: A sealing part (21) used to seal the gap between the rotor and the housing. Support (22) stacked on the fixed mounting plate; The sealing part (21), the support part (22) and the pivot (7) form a lever.

7. A radial seal for a rotary air preheater according to any one of claims 1 to 6, wherein: It also includes a clamping plate (8) and a compensation plate (9). The fixed mounting plate (1) is sandwiched between the clamping plate 8 and the rotor partition. The compensation plate (9) is provided on the other side of the partition. The compensation plate is provided with a fork (91). The fork (91) passes through the partition and is connected to the fixed mounting plate (1).

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