Novel rolling type flexible sealing device for air pre-heater

Abstract

The invention discloses a novel rolling type flexible sealing device for an air pre-heater, and belongs to the technical field of air pre-heater sealing, the novel rolling type flexible sealing device comprises a movable sealing plate and a fixed plate, the top of the movable sealing plate is provided with an extension section, two grooves are symmetrically formed in the movable sealing plate, and roller shafts are arranged in the grooves; and two bearing seats are symmetrically and fixedly connected to the positions, located on the two sides of the roller shaft, of the lower portion of the extending section, and a core shaft penetrates through the roller shaft and the two bearing seats, and a novel rolling type flexible sealing mechanism is adopted, so that a mushroom-shaped deformation gap between the movable sealing plate and the fan-shaped plate can be elastically compensated; the air pre-heater can keep elastic rolling contact with the fan-shaped plate for a long time, so that abrasion of the sealing piece to the fan-shaped plate is greatly reduced, a good sealing state can be kept in a long time, the shutdown maintenance time and the use cost of repeatedly replacing the sealing piece are greatly reduced, and the air pre-heater is kept low in air leakage rate for a long time. And the real purposes of high-benefit energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of air preheater sealing, in particular to a novel rolling flexible sealing device for an air preheater. Background Art

[0002] At present, the air preheater is a heat exchange device used in large boilers. Its air leakage rate directly affects the efficiency of the boiler. The air leakage rate of the air preheater is an important indicator affecting the efficiency of the boiler. The lower the air preheater leakage rate, the higher the boiler efficiency.

[0003] Traditional air preheater units all use rigid sealing plates in the radial direction. Especially when the air preheater is running hot, the rotor will undergo "mushroom-shaped" deformation due to the temperature difference between the hot and cold ends exceeding 200°C, resulting in a large air leakage area on the outside of the hot end. The air leakage rate is generally above 8%, and most units can reach an air leakage rate of more than 10% after a few years of operation. At the same time, traditional rigid seals will cause serious wear and tear on the fan plates after use at the cold end of the air preheater. The fan plates need to be replaced every one or two years, and the drive motor current increases by about 3A-5A, which will increase the power loss of the plant. In addition, the product life is relatively short. In particular, the cold end of the unit after the denitrification modification is more corrosive. Many products cannot withstand low-temperature condensation corrosion, which shortens the product life.

[0004] There has been a kind of air preheater rolling flexible seal on the market. The sealing mechanism is designed as a spring hinge mechanism. A roller is embedded on the sealing arc surface. The outer edge of the roller is slightly higher than the sealing arc surface. The sealing arc surface is in long-term rolling contact with the fan plate, which can elastically compensate for the deformation gap caused by the hot "mushroom-shaped" deformation and does not cause significant wear on the fan plate. However, because the roller is in an oil-free dry friction state for a long time, and there is always sulfuric acid corrosion and smoke erosion in the operating environment, the inside of the roller is particularly susceptible to wear. After wear, the outer edge of the roller will gradually be lower than the sealing arc surface, resulting in sliding contact instead of rolling contact between the sealing arc surface and the fan plate. The friction force becomes greater, and the wear on the fan plate will also become greater, which not only shortens the service life of the product, but also causes operating current fluctuations, posing a safety hazard. For this reason, a new type of air preheater rolling flexible sealing device is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a novel rolling flexible sealing device for an air preheater to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a novel rolling flexible sealing device for an air preheater, comprising a movable sealing plate and a fixed plate, wherein the movable sealing plate is provided with an extension section at the top, two grooves are symmetrically formed on the movable sealing plate, rollers are provided in the grooves, two receiving seats are symmetrically fixedly connected below the extension section and located on both sides of the roller, and a core shaft passes through the roller and the two receiving seats;

[0007] Wherein, two installation grooves are symmetrically provided on both sides of the roller shaft, and wear-resistant balls are evenly installed in the installation grooves.

[0008] As a further preferred embodiment of the present technical solution, the roller, wear-resistant balls and core shaft are made of materials with a hardness greater than 70HRC, thereby increasing the wear resistance of the roller component.

[0009] As a further preferred embodiment of the present technical solution: a threaded hole is provided on the receiving seat, a receiving groove is provided on the core shaft, and the core shaft is an eccentric shaft;

[0010] Wherein, the threaded hole and the receiving groove are located on the same axis.

[0011] As a further preferred embodiment of the present technical solution: the threaded hole and the receiving groove are used to fix the core shaft in the receiving seat, and to facilitate the later adjustment of the core shaft. The core shaft adopts an eccentric crankshaft structure, the shaft diameters at both ends are consistent and have the same axis, the shaft diameter in the middle part is thicker and is in contact with the wear-resistant balls, thereby forming an eccentricity with the end shafts on both sides.

[0012] As a further preferred embodiment of the present technical solution: the long-term rolling contact between the movable sealing plate and the sector plate effectively avoids wear between the movable sealing plate and the air preheater sector plate, and thus multiple adjustments can be achieved repeatedly, greatly extending the service life of the roller shaft component.

[0013] As a further preferred embodiment of the present technical solution: a rotating shaft sleeve is installed on one side of the movable sealing plate adjacent to the fixed plate, and a rotating shaft is installed in the rotating shaft sleeve;

[0014] Wherein, the rotating shaft sleeve includes at least two sleeves 1 and at least one sleeve 2, and the sleeves 1 and the sleeves 2 are arranged alternately.

[0015] As a further preferred embodiment of the present technical solution, the rotation effect of the movable sealing plate is achieved by means of a rotating shaft sleeve and a rotating shaft.

[0016] As a further preferred embodiment of the present technical solution: a bent section is provided on the top of the fixing plate, and two mounting holes are symmetrically provided on the fixing plate, the bent section receives the first sleeve, and the mounting holes facilitate the fixing plate to be fixed to the radial partition plate of the rotor;

[0017] Among them, the two sleeves 1 are connected to the fixed plate, and the two sleeves 2 are connected to the movable sealing plate. The above arrangement realizes the rotation effect of the movable sealing plate.

[0018] As a further preferred embodiment of the present technical solution: two support seats are symmetrically fixedly connected below the bending section and on one side adjacent to the two mounting holes, and lower spring seats are installed in the two support seats. The lower spring seats are supported by the support seats, and the compression spring is connected through the lower spring seats.

[0019] As a further preferred embodiment of the present technical solution: two upper spring seats are symmetrically fixedly connected below the extension section and on one side adjacent to the two roller shafts, and a compression spring is installed on the side adjacent to the upper spring seat of the lower spring seat. The compression spring is connected through the upper spring seat, and the compression spring squeezes the movable sealing plate to realize elastic upward and downward rotation with the rotating shaft as the axis.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention adopts a new rolling flexible sealing mechanism, which can not only elastically compensate for the "mushroom-shaped" deformation gap between the movable sealing plate and the sector plate, but also maintain elastic rolling contact with the sector plate for a long time, thereby greatly reducing the wear of the movable sealing plate on the sector plate. In this way, a good sealing state can be maintained for a long time, greatly reducing downtime for maintenance and the cost of repeated replacement of seals. As a result, the air preheater can maintain a low air leakage rate for a long time, achieving the goal of truly high-efficiency energy conservation and emission reduction;

[0022] 2. The present invention provides a long-life roller mechanism. The roller mechanism adopts high-strength wear-resistant materials, thereby greatly extending the service life of the roller. After the roller has been used for a period of time and has a certain amount of wear, the height of the roller can be easily and multiple times adjusted online, so that the overall service life of the device is further extended (more than doubled). The entire mechanism can be wear-resistant and corrosion-resistant for a long time, so that the entire sealing device unit can remain intact within an overhaul cycle or even longer, thereby reducing the air leakage rate to a lower level and achieving the effect of high-efficiency energy saving and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of a novel air preheater rolling flexible sealing device of the present invention;

[0024] Figure 2 This is a side structural schematic diagram of a novel rolling flexible sealing device for an air preheater according to the present invention;

[0025] Figure 3 This is a schematic diagram of the installation structure of the movable sealing plate and the roller in a novel rolling flexible sealing device for an air preheater according to the present invention;

[0026] Figure 4 This is a structural schematic diagram of the first movable sealing plate in a novel air preheater rolling flexible sealing device of the present invention;

[0027] Figure 5 This is a structural schematic diagram of a fixed plate in a novel rolling flexible sealing device for an air preheater according to the present invention;

[0028] Figure 6 This is a schematic diagram of the exploded structure of a roller in a novel air preheater rolling flexible sealing device of the present invention;

[0029] Figure 7 This is a structural schematic diagram of a core shaft in a novel rolling flexible sealing device for an air preheater according to the present invention;

[0030] Figure 8 This is a second structural schematic diagram of a movable sealing plate in a novel air preheater rolling flexible sealing device of the present invention.

[0031] In the figure: 1. movable sealing plate; 11. extension section; 12. groove; 2. fixed plate; 21. bending section; 22. mounting hole; 3. rotating shaft sleeve; 31. sleeve 1; 32. sleeve 2; 4. rotating shaft; 5. roller; 51. mounting groove; 52. wear-resistant ball; 6. receiving seat; 61. threaded hole; 7. core shaft; 71. receiving groove; 8. support seat; 9. lower spring seat; 10. upper spring seat; 101. compression spring. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] Example 1

[0034] See also Figures 1-8 The present invention provides a technical solution: a novel rolling flexible sealing device for an air preheater, comprising a movable sealing plate 1 and a fixed plate 2. An extension section 11 is provided on the top of the movable sealing plate 1. Two grooves 12 are symmetrically formed on the movable sealing plate 1. A roller shaft 5 is provided in the groove 12. Two receiving seats 6 are symmetrically welded below the extension section 11 and on both sides of the roller shaft 5. A core shaft 7 passes through the roller shaft 5 and the two receiving seats 6.

[0035] Two mounting grooves 51 are symmetrically provided on both sides of the roller shaft 5 , and wear-resistant balls 52 are evenly installed in the mounting grooves 51 .

[0036] In this embodiment, specifically: the roller 5, wear-resistant balls 52 and core shaft 7 are all updated with "silicon nitride" and metal ceramics, so that the material hardness is greater than 70HRC (Rockwell hardness), which can greatly increase the wear resistance of the roller 5 component and extend its service life exponentially.

[0037] In this embodiment, specifically: a threaded hole 61 is opened on the receiving seat 6, a receiving groove 71 is opened on the core shaft 7, and the core shaft 7 is an eccentric shaft;

[0038] The threaded hole 61 and the receiving groove 71 are located on the same axis.

[0039] In this embodiment, specifically: the threaded hole 61 and the receiving groove 71 are provided, on the one hand, for fixing the core shaft 7 in the receiving seat 6, and on the other hand, for facilitating the later adjustment of the core shaft 7. The core shaft 7 adopts an eccentric crankshaft structure, with the same shaft diameter at both ends and the same axis. The shaft diameter of the middle part is thicker and contacts with the wear-resistant ball 52, thereby forming an eccentricity with the end shafts on both sides, and the eccentricity is greater than 2 mm.

[0040] In this embodiment, specifically: the end shafts on both sides of the core shaft 7 are inserted into the receiving seats 6 on both sides of the roller shaft 5, so that the core shaft 7 can be rotated freely in the roller shaft 5. After rotating to a suitable position, it is fixed by a cotter pin. According to the principle of eccentric crankshaft, during initial use, the position of the core shaft 7 in the receiving seat 6 is rotated so that the outer edge of the roller shaft 5 is slightly higher than the extension section 11 of the movable sealing plate 1. After the entire device has been used for a period of time and the roller shaft 5 has undergone a certain amount of wear, the position of the core shaft 7 in the receiving seats 6 on both sides is rotated, and the eccentric effect is utilized to make the core shaft 7 drive the roller shaft 5 to be higher than the extension section 11 of the movable sealing plate 1 again.

[0041] In this embodiment, specifically: the long-term rolling contact between the movable sealing plate 1 and the fan-shaped plate effectively avoids the wear between the movable sealing plate 1 and the air preheater fan-shaped plate, and thus multiple adjustments can be achieved repeatedly, greatly extending the service life of the roller shaft 5 component, thereby avoiding the material cost and labor cost of multiple repairs and replacements of the product.

[0042] In this embodiment, specifically: a rotating shaft sleeve 3 is installed on one side of the movable sealing plate 1 adjacent to the fixed plate 2, and a rotating shaft 4 is installed in the rotating shaft sleeve 3;

[0043] The rotating shaft sleeve 3 includes at least two first sleeves 31 and at least one second sleeve 32 , and the first sleeve 31 and the second sleeve 32 are arranged alternately.

[0044] In this embodiment, specifically, the rotating shaft sleeve 3 and the rotating shaft 4 are provided to realize the rotation effect of the movable sealing plate 1 .

[0045] Example 2

[0046] A novel rolling flexible sealing device for an air preheater has a bent section 21 at the top of a fixed plate 2. Two mounting holes 22 are symmetrically formed on the fixed plate 2. The bent section 21 is used to receive a sleeve 31, while the mounting holes 22 facilitate fixing the fixed plate 2 to the rotor radial partition plate.

[0047] Among them, the two sleeves 1 31 are connected to the fixed plate 2, and the sleeve 2 32 is connected to the movable sealing plate 1. The above arrangement realizes the rotation effect of the movable sealing plate 1.

[0048] In this embodiment, specifically: two support seats 8 are symmetrically welded below the bending section 21 and on one side adjacent to the two mounting holes 22, and lower spring seats 9 are installed in the two support seats 8. The support seats 8 are provided to receive the lower spring seats 9, and the lower spring seats 9 are provided to connect the compression spring 101.

[0049] In this embodiment, specifically: two upper spring seats 10 are symmetrically welded below the extension section 11 and on one side adjacent to the two roller shafts 5, and a compression spring 101 is installed on the side of the lower spring seat 9 adjacent to the upper spring seat 10. The upper spring seat 10 is used to connect the compression spring 101, and the compression spring 101 is squeezed to enable the movable sealing plate 1 to achieve elastic upward and downward rotation around the rotating shaft 4 as the axis.

[0050] Working principle: When in use, the movable sealing plate 1 and the fixed plate 2 are rotated by the provided rotating shaft sleeve 3 and the rotating shaft 4, and the compression spring 101 squeezes the movable sealing plate 1 to realize the elastic rotation up and down with the rotating shaft 4 as the axis. At the same time, the position of the rotating core shaft 7 in the receiving seat 6 is rotated so that the outer edge of the roller shaft 5 is slightly higher than the extension section 11 of the movable sealing plate 1. After the device as a whole has been used for a period of time and the roller shaft 5 has a certain amount of wear, the position of the rotating core shaft 7 in the receiving seats 6 on both sides is rotated. By utilizing the eccentric effect, the core shaft 7 drives the roller shaft 5 to be higher than the extension section 11 of the movable sealing plate 1 again for flexible rolling, and the matching clearance between the movable sealing plate 1, the rotating shaft sleeve 3 and the roller shaft 5 is designed to be minimized, thereby reducing the air leakage gap.

[0051] Note: It needs to be further explained that when in use, multiple rolling flexible seals are installed on the radial partition plate of the air preheater, and the hot end rolling flexible seal is higher than the sealing plane of the sector plate. When the rotor is heated and deformed into a "mushroom shape", the roller shaft 5 still fits with the sector plate to achieve a sealing effect.

[0052] Among them, during long-term operation, the back of the sealing sticker is in rolling contact, the friction is minimal, and thus the wear on the sealing surface and the sector plate is minimized.

[0053] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A novel rolling flexible sealing device for an air preheater, comprising a movable sealing plate (1) and a fixed plate (2), characterized in that: An extension section (11) is provided on the top of the movable sealing plate (1), two grooves (12) are symmetrically provided on the movable sealing plate (1), a roller shaft (5) is provided in the groove (12), two receiving seats (6) are symmetrically fixedly connected below the extension section (11) and located on both sides of the roller shaft (5), and a core shaft (7) passes through the roller shaft (5) and the two receiving seats (6); Two mounting grooves (51) are symmetrically provided on both sides of the roller shaft (5), and wear-resistant balls (52) are evenly installed in the mounting grooves (51).

2. The novel air preheater rolling flexible sealing device according to claim 1 is characterized in that: The receiving seat (6) is provided with a threaded hole (61), the core shaft (7) is provided with a receiving groove (71), and the core shaft (7) is an eccentric shaft; The threaded hole (61) and the receiving groove (71) are located on the same axis.

3. The novel air preheater rolling flexible sealing device according to claim 1 is characterized in that: A rotating shaft sleeve (3) is installed on one side of the movable sealing plate (1) adjacent to the fixed plate (2), and a rotating shaft (4) is installed in the rotating shaft sleeve (3); Wherein, the rotating shaft sleeve (3) includes at least two sleeves 1 (31) and at least one sleeve 2 (32), and the sleeves 1 (31) and the sleeves 2 (32) are arranged in an alternating manner.

4. The novel air preheater rolling flexible sealing device according to claim 3 is characterized in that: The top of the fixing plate (2) is provided with a bent section (21), and two mounting holes (22) are symmetrically provided on the fixing plate (2); The two sleeves (31) are connected to the fixed plate (2), and the two sleeves (32) are connected to the movable sealing plate (1).

5. The novel air preheater rolling flexible sealing device according to claim 4 is characterized in that: Two support seats (8) are symmetrically fixedly connected below the bending section (21) and located on one side adjacent to the two mounting holes (22), and lower spring seats (9) are installed in the two support seats (8).

6. The novel air preheater rolling flexible sealing device according to claim 5 is characterized in that: Two upper spring seats (10) are symmetrically fixedly connected below the extension section (11) and located on adjacent sides of the two roller shafts (5). A compression spring (101) is installed on the adjacent side of the lower spring seat (9) and the upper spring seat (10).

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