Air preheater multi-sheet sealing structure with elastic sheets easy to replace

Abstract

The utility model discloses an air preheater multi-sheet sealing structure with elastic sheets easy to replace. The air preheater multi-sheet sealing structure comprises the elastic sheets and basic thick sheets which are overlapped in the thickness direction. The elastic sheet is in a long strip shape formed by splicing more than two elastic sheet sections along the length direction; the basic thick sheet is in a long strip shape formed by splicing more than two basic thick sheet sections along the length direction; the length of the elastic sheet section is not greater than 2 / 3 of the length of the corresponding basic thick section; more than two positioning bosses are arranged on the elastic sheet section; more than four positioning concave holes are formed in the basic thick segment; the positioning boss and the positioning concave hole can be freely matched; and the positioning bosses on the elastic thin sheet section are movably matched in the positioning concave holes in the basic thick sheet section. The elastic sheet section and the basic thick sheet section are fixed in relative positions through matching of the positioning bosses and the positioning concave holes, and when the elastic sheet is damaged due to abrasion, blowing damage and the like, the elastic sheet can be locally damaged and locally replaced, repositioning is not needed, and cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of Ljungstrom air preheater sealing, relates to an air preheater multi-piece sealing structure easy to replace elastic sheet. BACKGROUND

[0002] Ljungstrom air preheater (hereinafter referred to as "air preheater") is a kind of heat exchange equipment for large power station boiler, it uses the heat of boiler flue gas to heat the air required for combustion.Air preheater rotor is composed of a large number of heat storage elements, when the rotor slowly rotates, flue gas and air reverse alternately flow through the rotor, heat storage element absorbs heat on the flue gas side, and releases heat on the air side, thereby achieving the preheating effect of reducing the flue gas temperature of boiler, improving the hot air temperature and improving the economic efficiency of power plant.

[0003] Air preheater rotor is actually a huge cylinder, the rotor is from cold state to hot state, due to the temperature difference of upper and lower end faces and the weakening of steel rigidity after heating, "mushroom-shaped" deformation is generated.Therefore, when installing in cold state, air preheater rotor and stator need to reserve gap, the size of the reserved gap depends on the deformation amount of each component of air preheater, especially the deformation amount of air preheater rotor;In principle, it is necessary to ensure that the rotor and stator of air preheater do not collide under any working condition, so as to prevent the rotor from being stuck and causing safety accidents.

[0004] Since the air side pressure of air preheater is higher than the flue gas side pressure, sealing device is needed to reduce the leakage of air to flue gas side, so as to reduce energy loss.The conventional method in engineering is to install sealing sheet on the rotor baffle, the sealing sheet and the rotor baffle are connected by bolt, the rotor baffle is generally long, and the shorter sealing sheet is connected head to tail to form complete sealing.The traditional sealing sheet is straight sheet type, and larger sealing gap and smaller sealing sheet thickness need to be reserved during installation, so as to ensure the safe and stable operation of air preheater.

[0005] In engineering applications, the traditional sealing sheet exposes some problems: ① The too small reserved gap of the traditional sealing sheet may cause the rotor of the air preheater to be stuck, and the too large reserved gap may increase the leakage, so in engineering, a compromise between the two is often considered; ② The traditional sealing sheet is relatively thin, and the sealing sheet is easy to be twisted and deformed in a high-temperature environment, and the sealing gap is expanded; ③ The high-temperature flue gas is mixed with coal ash, and under the driving of the high-speed airflow, the sealing sheet is continuously eroded, and in addition to the influence of corrosion, the gap between the traditional sealing sheet and the sealing surface will be continuously expanded; ④ In order to take into account the matching characteristics of the sealing sheet and the sealing surface and ensure that the air leakage rate is not too large during long-term use, sometimes the sealing sheet is set as a multi-sealing structure, which at least includes an elastic sheet and a basic thick sheet welded together, the gap between the elastic sheet and the sealing surface is smaller than the gap between the basic thick sheet and the sealing surface, so as to ensure that even if the elastic sheet and the sealing surface are collided and ground, the elastic sheet and the sealing surface are collided and ground first. Because the elastic sheet and the basic thick sheet are welded together, once the elastic sheet is damaged due to wear, blow damage and the like, the basic thick sheet needs to be replaced together, and the positioning needs to be reinstalled, and there is a problem of high replacement and maintenance cost. Content of the utility model

[0006] The utility model aims at providing an air preheater multi-sealing structure with an elastic sheet easy to replace, which overcomes the technical problems of large difficulty in replacing the elastic sheet and high cost in the prior art.

[0007] To solve the above technical problems, the technical scheme of the utility model is as follows:

[0008] An air preheater multi-sealing structure with an elastic sheet easy to replace, comprising at least one elastic sheet and at least one basic thick sheet (that is, the elastic sheet and the basic thick sheet are overlapped together in the thickness direction) overlapped in the thickness direction, the thickness of each elastic sheet is between 0.8-1.6 mm, and the thickness of each basic thick sheet is between 2-10 mm; characterized in that:

[0009] The elastic sheet is a long strip formed by splicing two or more elastic sheet segments in the length direction; and the basic thick sheet is a long strip formed by splicing one or more basic thick sheet segments in the length direction;

[0010] Two or more elastic sheet segments are covered on the same basic thick sheet segment in the length direction, and the length of each elastic sheet segment is not greater than 2 / 3 of the length of the basic thick sheet segment; two or more positioning bosses are arranged on each elastic sheet segment, and the height of the positioning boss is at least 2 mm; four or more positioning recesses are arranged on each basic thick sheet segment, and the recess depth of the positioning recess is at least 2 mm; the positioning boss and the positioning recess can be freely matched, that is, any one positioning boss can be matched in any one positioning recess; and the positioning boss on each elastic sheet segment is movably matched in the positioning recess on the basic thick sheet segment;

[0011] The one end of each elastic sheet segment and each base thick segment in the width direction is a fixed end, and the other end is a free end, the fixed end of each elastic sheet segment and each base thick segment is provided with a waist-shaped mounting hole, and the waist-shaped mounting hole on each elastic sheet segment is aligned with the waist-shaped mounting hole on the base thick segment where the elastic sheet segment is located;

[0012] Each base thick segment and the corresponding elastic sheet segment are installed on the radial baffle of the air preheater rotor through the mounting bolt which simultaneously penetrates the waist-shaped mounting holes on the elastic sheet segment and the base thick segment, and the free end of the elastic sheet segment exceeds the free end of the base thick segment.

[0013] The applicant has found through research that, when the elastic sheet exists damage problems such as wear and blowout, the elastic sheet can be replaced separately in segments by using the above-mentioned air preheater multi-seal structure, and only the mounting bolt in the corresponding segment waist-shaped mounting hole needs to be removed. Since the length of the elastic sheet segment is not greater than 2 / 3 of the length of the base thick segment, removing the mounting bolt of the waist-shaped mounting hole corresponding to one segment of the elastic sheet segment will not cause the installation position of the base thick segment to change. The relative position between the elastic sheet segment and the base thick segment is fixed through the cooperation of the positioning boss and the positioning recess, thereby ensuring that the sealing sheet does not need to be reinstalled and positioned as a whole, saving replacement and maintenance costs.

[0014] The above-mentioned overlapping of the elastic sheet and the base thick sheet in the thickness direction overcomes or alleviates the problem of the expansion of the sealing gap caused by the easy distortion and corrosion of the sealing sheet in a high-temperature environment. The free end of the elastic sheet segment exceeds the free end of the base thick segment, so that a small sealing gap can be reserved during operation, and even if there is a collision and grinding, the air preheater rotor is not easy to be stuck. Moreover, the elastic sheet segment is prone to wear, blowout and other damage problems. By using the technical solution of the present application, only the elastic sheet needs to be replaced, and local damage and local replacement can be achieved, which is convenient, safe, reliable and low in cost.

[0015] The elastic sheet segment and the base thick segment where it is located have a corresponding relationship, that is, the base thick segment and the elastic sheet segment covering the base thick segment have a corresponding relationship.

[0016] In order to improve the stability of installation, the fixed end of each elastic sheet segment and each base thick segment is provided with at least two waist-shaped mounting holes. In this way, uncontrollable twisting of the elastic sheet segment during operation can be avoided.

[0017] In order to save costs and facilitate installation and control, the number of waist-shaped mounting holes of the base thick segment is equal to the sum of the number of waist-shaped mounting holes on all elastic sheet segments covering the base thick segment, and they are one-to-one corresponding.

[0018] In order to balance the cost and stability, the number of positioning recesses of the base thick segment is equal to the sum of the number of positioning bosses on all elastic sheet segments covering the base thick segment, and they are one-to-one corresponding.

[0019] For easy disassembly, preferably, the positioning boss is circular, and the positioning recess is waist-shaped, with the length direction of the positioning recess (waist-shaped) being consistent with the length direction of the base thick piece.

[0020] For easy preparation, and also for easy matching of the positioning boss and the positioning recess, the shape and size of each positioning boss are the same, and the shape and size of each positioning recess are the same.

[0021] For easy manufacturing and installation, it is further preferred that the width of the positioning recess is 0.2-1mm larger than the diameter of the positioning boss, and the length of the positioning recess is 2-10mm larger than the diameter of the positioning boss.

[0022] To improve the overall sealing performance, it is further preferred that the height of the positioning boss is not greater than the depth of the positioning recess.

[0023] For easy processing and manufacturing, it is preferred that the positioning recess is a through hole.

[0024] To improve the overall sealing performance, it is preferred that the positioning recess is a blind hole.

[0025] To ensure the overall sealing performance of the device, the elastic sheet segments are arranged along the length direction on each base thick piece segment. That is, the length of the elastic sheet segment on the same base thick piece segment is equal to the length of the base thick piece segment. In the width direction, the free end of the elastic sheet segment exceeds the free end of the base thick piece segment.

[0026] For easy manufacturing and disassembly and maintenance, the lengths of the elastic sheet segments on the same base thick piece segment are equal, and the length of the base thick piece segment is an integer corresponding to the length of the elastic sheet segment.

[0027] It is further preferred that the lengths of the base thick piece segments are equal, and the lengths of the elastic sheet segments are also equal, which facilitates preparation, storage and record keeping, and also facilitates disassembly and replacement.

[0028] For easy preparation and to ensure stability in use, the positioning boss is welded to the elastic sheet.

[0029] A method for replacing an elastic sheet of a multi-piece sealing structure of an air preheater, which uses the multi-piece sealing structure of the air preheater with the easily replaceable elastic sheet, when the elastic sheet is damaged, the damaged elastic sheet segment is determined, and the mounting bolt in the waist-shaped mounting hole corresponding to the damaged elastic sheet segment is removed and replaced with an elastic sheet segment.

[0030] If two or more elastic sheet segments on the same base thick segment are damaged, they are replaced one by one (that is, after replacing an elastic sheet segment, the next one is replaced), because the length of the elastic sheet segment is not greater than 2 / 3 of the length of the base thick segment, the mounting bolt of the waist-shaped mounting hole corresponding to the removed elastic sheet segment is removed, and the cooperation of the remaining mounting bolt on the base thick segment and the positioning convex hole does not cause the installation position of the base thick segment to change, so that the base thick segment does not need to be re-installed and positioned as a whole.

[0031] The elastic sheet segments not on the same base thick segment can be replaced simultaneously or one by one.

[0032] The technologies not mentioned in the utility model are prior art.

[0033] The utility model discloses an air preheater multi-piece sealing structure of easy elastic sheet replacement, and the relative position is fixed through the cooperation of the positioning convex and the positioning concave between the elastic sheet segment and the base thick segment. When the elastic sheet is damaged due to wear and tear, blowout or the like, the elastic sheet can be replaced separately in sections. Only the mounting bolt in the corresponding waist-shaped mounting hole needs to be removed. Because the length of the elastic sheet segment is not greater than 2 / 3 of the length of the base thick segment, the removal of the mounting bolt of the waist-shaped mounting hole corresponding to the removed elastic sheet segment does not cause the installation position of the base thick segment to change. Therefore, when the elastic sheet segment is replaced, repositioning is not needed, the dismounting and maintenance cost is saved, and the structure is simple and stable, and the dismounting is simple and convenient. ACCURACY OF DRAWINGS

[0034] Figure 1 It is an explosion schematic view of one section of the utility model discloses an air preheater multi-piece sealing structure of easy elastic sheet replacement.

[0035] Figure 2 It is a front view of one section of the utility model discloses an air preheater multi-piece sealing structure of easy elastic sheet replacement.

[0036] Figure 3 It is a side view of Figure 2 .

[0037] Figure 4 It is a front view of the elastic sheet segment.

[0038] Figure 5 It is a side view of Figure 4 .

[0039] In the drawing, 1 is a base thick segment, 1-1 is a positioning concave, 1-2 is a waist-shaped mounting hole on the base thick segment, 2 is an elastic sheet segment, 2-1 is a positioning convex, and 2-2 is a waist-shaped mounting hole on the elastic sheet segment. DETAILED DESCRIPTION

[0040] The present invention will be described in detail below with reference to specific embodiments.

[0041] Example 1

[0042] like Figures 1-4 As shown, an air preheater multi-plate sealing structure with easily replaceable elastic sheet includes an elastic sheet and a base sheet stacked together along the thickness direction. The thickness of the elastic sheet is 1 mm (after practical verification, values ​​of 0.8 mm, 1.2 mm, 1.4 mm, etc. can also be used), and the thickness of the base sheet is 5 mm (after practical verification, values ​​of 2 mm, 3 mm, 9 mm, etc. can also be used).

[0043] The elastic sheet is a long strip formed by splicing two or more elastic thin segments along the length direction; the base thick sheet is a long strip formed by splicing one or more base thick segments along the length direction; the length of each base thick segment is equal, and the length of each elastic thin segment is also equal.

[0044] Each base thick segment is covered with elastic thin segments along its length. The length of the base thick segment is twice the length of the elastic thin segments, meaning that two elastic thin segments cover the same base thick segment along its length. Each elastic thin segment has two positioning bosses with a height of 2mm. Each base thick segment has four positioning recesses with a depth of 2.1mm. The positioning bosses and positioning recesses can be freely matched, meaning that any positioning boss can be matched into any positioning recess. The four positioning bosses on the two elastic thin segments are respectively movable and fitted into the four positioning recesses on their respective base thick segments.

[0045] Each elastic thin segment and each base thick segment has a fixed end at one end and a free end at the other end in the thickness direction. The fixed end of each elastic thin segment is provided with three equally spaced waist-shaped mounting holes, and the fixed end of each base thick segment is provided with six equally spaced waist-shaped mounting holes. The six waist-shaped mounting holes on the two elastic thin segments are aligned with the six waist-shaped mounting holes on the base thick segment.

[0046] Each base thick segment and its corresponding elastic thin segment are mounted on the radial partition of the air preheater rotor by mounting bolts that pass through the waist-shaped mounting holes of both (elastic thin segment and base thick segment). The free end of the elastic thin segment extends beyond the free end of the base thick segment.

[0047] Through practice, when the elastic sheet has damage problems such as wear and blow, the elastic sheet can be replaced separately in sections. Only the mounting bolt in the corresponding waist-shaped mounting hole needs to be removed. Because the length of the elastic sheet section is only half of the length of the base thick sheet section, removing the mounting bolt of the corresponding waist-shaped mounting hole of the elastic sheet section will not cause the installation position of the base thick sheet section to change. The relative position between the elastic sheet section and the base thick sheet section is fixed through the cooperation of the positioning boss and the positioning recess hole, thereby ensuring that the sealing sheet does not need to be reinstalled and positioned as a whole, and saving replacement and maintenance costs.

[0048] Embodiment 2

[0049] On the basis of embodiment 1, the following improvements are further made: In order to facilitate disassembly and assembly, the positioning boss is circular, and the positioning recess hole is waist-shaped. The length direction of the positioning recess hole is consistent with the length direction of the base thick sheet. The shapes and sizes of the positioning bosses are all the same, and the shapes and sizes of the positioning recess holes are all the same. The width of the positioning recess hole is 0.2 mm larger than the diameter of the positioning boss (through practice verification, values of 0.3 mm, 0.5 mm, 0.7 mm, etc. can also be taken), and the length of the positioning recess hole is 5 mm larger than the diameter of the positioning boss (through practice verification, values of 3 mm, 7 mm, 9 mm, etc. can also be taken).

[0050] Embodiment 3

[0051] On the basis of embodiment 2, the following improvements are further made: In order to facilitate processing and manufacturing, the positioning recess hole is a through hole, and the positioning boss is welded on the elastic sheet.

[0052] Embodiment 4

[0053] On the basis of embodiment 2, the following improvements are further made: In order to improve the overall sealing performance, the positioning recess hole is a blind hole, and the positioning boss is welded on the elastic sheet.

[0054] Embodiment 5

[0055] Different from embodiment 3 or 4 is that the length of the base thick sheet section is three times the length of the elastic sheet section, that is, the same base thick sheet section covers three elastic sheet sections along the length direction; the fixed end of each elastic sheet section is provided with two waist-shaped mounting holes, and the fixed end of each base thick sheet section is provided with six equally spaced waist-shaped mounting holes; the six waist-shaped mounting holes on the three elastic sheet sections are aligned with the six waist-shaped mounting holes on the base thick sheet section, and the rest are referred to embodiment 3 or 4.

[0056] Embodiment 6

[0057] Different from example 5: the same basic thick segment corresponds to three unequal length elastic thin segments, the lengths of the three elastic thin segments are 1 / 2, 1 / 3 and 1 / 6 of the length of the basic thick segment. Compared with example 5, the production is relatively complex, and elastic thin segments of different lengths need to be processed.

[0058] A method for replacing elastic thin pieces of a multi-piece sealing structure of an air preheater, which adopts the above-mentioned multi-piece sealing structure of the air preheater with easily replaceable elastic thin pieces, when the elastic thin pieces are damaged, the damaged elastic thin segment is determined, and the mounting bolt in the waist-shaped mounting hole corresponding to the damaged elastic thin segment is removed to replace the elastic thin segment;

[0059] If two or more elastic thin segments on the same basic thick segment are damaged, they are replaced one by one (that is, after replacing one elastic thin segment, the next one is removed), because the length of the elastic thin segment is not greater than 2 / 3 of the length of the basic thick segment, the mounting bolt of the waist-shaped mounting hole corresponding to the removed elastic thin segment is removed, and the remaining mounting bolts on the basic thick segment cooperate with the positioning concave hole of the positioning boss, so that the installation position of the basic thick segment does not change, and the positioning is not needed to be reinstalled as a whole;

[0060] The elastic thin segments not on the same basic thick segment can be replaced simultaneously or one by one.

[0061] The above-mentioned multi-piece sealing structure of the air preheater with easily replaceable elastic thin pieces, the relative position between the elastic thin segment and the basic thick segment is fixed through the matching of the positioning boss and the positioning concave hole, when the elastic thin piece is damaged due to wear, blow and the like, the elastic thin piece can be replaced separately in segments, and only the mounting bolt in the waist-shaped mounting hole corresponding to the segment needs to be removed. Because the length of the elastic thin segment is not greater than 2 / 3 of the length of the basic thick segment, the removal of the mounting bolt of the waist-shaped mounting hole corresponding to the removed elastic thin segment will not cause the installation position of the basic thick segment to change, so when the elastic thin segment is replaced, the positioning is not needed to be repositioned, the dismounting and maintenance costs are saved, and the structure is simple and stable, and the dismounting is simple and convenient.

[0062] The above-mentioned examples do not limit the utility model in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the utility model.

Claims

1. An air preheater multi-sheet sealing structure with replaceable elastic sheets, comprising at least one elastic sheet and at least one base sheet stacked along the thickness direction, each elastic sheet having a thickness of 0.8-1.6 mm, and each base sheet having a thickness of 2-10 mm; characterized in that: the elastic sheet is a long strip formed by splicing two or more elastic sheet segments along the length direction; and the base sheet is a long strip formed by splicing one or more base sheet segments along the length direction. Two or more elastic sheet segments are covered on the same base sheet segment along the length direction, and the length of each elastic sheet segment is not more than 2 / 3 of the length of the base sheet segment. Two or more positioning bosses are provided on each elastic sheet segment, and the height of the positioning boss is at least 2 mm. Four or more positioning recesses are provided on each base sheet segment, and the recess depth of the positioning recess is at least 2 mm. The positioning boss and the positioning recess can be freely matched.

2. The air preheater gasket arrangement of claim 1, wherein: The positioning boss on each elastic sheet segment is movably fitted in the positioning recess on the base sheet segment.

3. The air preheater gasket arrangement of claim 2, wherein: One end of each elastic sheet segment and each base sheet segment in the width direction is a fixed end, and the other end is a free end.

4. The easily replaceable spring sheet of the air preheater multi-sheet seal structure according to any one of claims 1 to 3, characterized in that: A waist-shaped mounting hole is provided on the fixed end of each elastic sheet segment and each base sheet segment.

5. The easily replaceable spring sheet air preheater gasket structure according to any one of claims 1-3, wherein: The waist-shaped mounting hole on each elastic sheet segment is aligned with the waist-shaped mounting hole on the base sheet segment.

6. The easily replaceable spring sheet air preheater gasket structure of any one of claims 1-3, wherein: Each base sheet segment and the corresponding elastic sheet segment are installed on the radial baffle of the air preheater rotor by means of an installation bolt passing through the waist-shaped mounting holes of both.

7. The easily replaceable spring sheet air preheater gasket structure of any one of claims 1-3, wherein: The free end of the elastic sheet segment protrudes beyond the free end of the base sheet segment.

8. The easily replaceable spring sheet air preheater gasket structure of any one of claims 1-3, wherein: The positioning boss is a circular ring, and the positioning recess is a waist shape.

9. The easily replaceable spring sheet air preheater gasket of any one of claims 1-3, wherein: The length direction of the positioning recess is consistent with the length direction of the base sheet.

10. The easily replaceable spring sheet air preheater gasket of any one of claims 1-3, wherein: The width of the positioning recess is 0.2-1 mm larger than the diameter of the positioning boss, and the length of the positioning recess is 2-10 mm larger than the diameter of the positioning boss. The height of the positioning boss is not more than the recess depth of the positioning recess. The positioning recess is a through hole. The positioning recess is a blind hole. The elastic sheet segments are distributed along the length direction on each base sheet segment. The lengths of the elastic sheet segments on the same base sheet segment are equal, and the length of the base sheet segment is an integer multiple of the length of the corresponding elastic sheet segment. The lengths of the base sheet segments are equal, and the lengths of the elastic sheet segments are also equal. The positioning boss is welded on the elastic sheet.

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