CN201555498U

CN201555498U - Dragging type sealing structure of air preheater

Info

Publication number: CN201555498U
Application number: CN200920211027XU
Authority: CN
Inventors: 蔡明坤; 张建国
Original assignee: Shanghai Boiler Works Co Ltd
Current assignee: Shanghai Boiler Works Co Ltd
Priority date: 2009-10-21
Filing date: 2009-10-21
Publication date: 2010-08-18
Anticipated expiration: 2019-10-21

Abstract

The utility model provides a dragging type sealing structure of an air preheater, which comprises a sealing strip and a pressure plate, wherein the sealing strip is fixedly connected to one end of a radial partition board through a bolt and a nut, and the pressure plate is arranged between the bolt and the nut. The dragging type sealing structure is characterized in that at least one curved flexible sealing strip is further included, the lower part of the flexible sealing strip is arranged between the sealing strip and the radial partition board, and the upper part of the flexible sealing strip is in contact with a sector plate or an axial sealing plate. The utility model has the advantages as follows: on the one hand, a reserved gap of the sealing structure is reduced, and on the other hand, the abrasion is reduced, and the service life is prolonged.

Description

A kind of air preheater towing shape hermetically-sealed construction

Technical field

The utility model relates to a kind of air preheater towing shape hermetically-sealed construction, be used in the radial seal of rotary regenerative air preheater and flue gas-flue gas heat exchange device and the axial seal to improve the sealing effectiveness of air preheater, reduce to leak out, belong to the rotary type heat exchanger technical field.

Background technology

Rotary regenerative air preheater is that steam generator system is used for reclaiming fume afterheat, and it utilizes the heat storage (generally claiming rotor) that continues by thermal current and cold airflow, has realized that heat is from the sustained delivery of thermal current to cold airflow.As shown in Figure 1, be radial seal and axial seal schematic diagram, rotor 1 is a kind of cylindrical structure, and the radially dividing plate 2 of a radial layout of piece is divided into several storehouse lattice 3 with rotor, and heat accumulating element is laid in inside.Common thermal current (boiler combustion gas, claim flue gas again) and cold airflow (being generally the air of sending into boiler) between the pressure difference, for avoiding two kinds of Gas Mixing in Cross flow amounts excessive, between two kinds of air-flows seal area being set separates, described seal area is made up of the fanning strip 4 (rotor has up and down) and the axial sealing plate 5 that are installed on the air preheating housing, radially installing radial seal 6 between dividing plate 2 and the fanning strip 4, radially installing axial seal 7 between dividing plate 2 and the axial sealing plate 5, reached and reduced the amount of air preheater air, and the definition percentage that the air capacity of flue gas accounts for the exhaust gas volumn that enters air preheater that bleeds is the air leak rate of air curtain of air preheater to smoke spillage.

As shown in Figure 2, be traditional radial seal structure schematic diagram, described radially dividing plate 2 is by bolt 10 and nut 9 fixed connection and sealing sheets 6, be provided with pressing plate 8 between diaphragm seal 6 and the nut 9, leave certain interval between diaphragm seal 6 and the fanning strip 4, be generally 0～3mm, traditional axial seal is identical with radial seal structure, there is following shortcoming in this structure: on the one hand, it is the steel plate manufacturing of 2～3mm that diaphragm seal 6 adopts thickness usually, suitable with sealing plate 4 material hardness, because temperature difference about during rotor 1 work finally causes rotor 1 mushroom-shaped surf deform to occur, deflection changes with rotor 1 upper and lower temperature difference, but if rotor 1 running temperature off-design numerical value will make diaphragm seal and sealing plate big gap or excessive abrasion occur; On the other hand, leave certain interval between diaphragm seal 6 and the fanning strip 4, this gap will produce certain leakage undoubtedly.

Summary of the invention

The purpose of this utility model provides a kind of air preheater hermetically-sealed construction, can reduce the gap that hermetically-sealed construction is reserved on the one hand, can reduce wear on the other hand, increases the service life.

In order to achieve the above object, the technical solution of the utility model provides a kind of air preheater towing shape hermetically-sealed construction, comprise by bolt and nut and be fixedly connected on the radially diaphragm seal of dividing plate one end, be provided with pressing plate between nut and the diaphragm seal, it is characterized in that, the flexible sealing fin that also comprises at least one bending shape, the bottom of flexible sealing fin are located at diaphragm seal and radially between the dividing plate, the top of flexible sealing fin contacts with fanning strip or axial sealing plate.

Further, the flexible sealing fin one of described bending shape has two, be respectively first flexible sealing fin and second flexible sealing fin, the bottom of first flexible sealing fin and second flexible sealing fin is located at diaphragm seal and radially between the dividing plate successively, the top of first flexible sealing fin and the angle between the diaphragm seal are 20-40 °, and the top of second flexible sealing fin and the angle between the diaphragm seal are 30-60 °.

It is the round-corner transition of 5-10mm that the bending part of described flexible sealing fin adopts radius.

The utility model has the advantages that:

1, preceding road flexible sealing fin is a soft material, the gap is not stayed in installation with sealing plate, after distortion appears in rotor, compressed by sealing plate, bending can occur, end and sealing plate base plate friction simultaneously, because of its hardness not high, thickness is also thin, and the end grinds off very soon, so can not produce bigger abrasion to the sealing plate base plate.

Do not stay the gap when 2, the bigger and sealing plate in road flexible sealing fin bending angle, back is installed yet, crookedly under the sealing plate compressing occur easily, frictional force is less, though the material hardness of usefulness near sealing plate, thin thickness, general end grinds off earlier, can not cause very galling to sealing plate.

3, in the space of flexible sealing fin and front and back, its eddy current effect can reduce the flow velocity of leakage current, thereby prolongs its service life.

4, behind the process actual motion, flexible sealing fin can provide real rotor operation gap data, adjusts gap between diaphragm seal and the sealing plate according to these data, avoids occurring between diaphragm seal and the sealing plate irrational excessive intermittency.

5, consider the variation of rotor deformation after operation a period of time, may cause flexible sealing fin to occur than the galling amount, cause slip to be gone up, therefore each maintenance preheater can make flexible sealing fin contact sealing plate again, recovers minimum clearance.

Description of drawings

Fig. 1 is radial seal and axial seal schematic diagram

Fig. 2 is traditional radial seal structure schematic diagram;

Fig. 3 is a radial seal structure schematic diagram of the present utility model.

The specific embodiment

Specify the utility model below in conjunction with embodiment.

Embodiment 1

As shown in Figure 3, be radial seal structure schematic diagram of the present utility model, described radial seal structure is made up of diaphragm seal 6, pressing plate 8, nut 9, bolt 10, first flexible sealing fin 11 and second flexible sealing fin 12.

Diaphragm seal 6 is fixedly connected on radially dividing plate 2 one ends by bolt 10 and nut 9, be provided with pressing plate 8 between nut 9 and the diaphragm seal 6, the bottom of first flexible sealing fin 11 and second flexible sealing fin 12 is located at diaphragm seal 6 and radially between the dividing plate 2 successively, angle between the top of first flexible sealing fin 11 and the diaphragm seal 6 is 20 °, angle between the top of second flexible sealing fin 12 and the diaphragm seal 6 is 30 °, and the top of first flexible sealing fin 11 and second flexible sealing fin 12 contacts with fanning strip 4.It is the round-corner transition of 5mm that the bending part of described flexible sealing fin adopts radius.

Wherein, first flexible sealing fin 11 adopts the lower material of hardness, as the aluminum alloy materials manufacturing, and thickness 2～3mm.Second flexible sealing fin 12 adopts the material of hardness near sealing plate 4 base plates, as resistant low alloy corrosion material (Corten, S-ten, A588 etc.), or stainless steel (SUS304, SUS316L, 1cr18Ni9Ti etc.) material manufacturing, thickness 1～2mm.The bending form can be the straight line bending, also can curve circular shape.Flexible sealing fin such as segmentation manufacturing, the junction should be weldingly connected or laminate continuous, to strengthen the bulk strength of diaphragm seal, avoids the two ends shake to damage, and also reduces the joint leadkage amount.

Embodiment 2

A kind of radial seal structure, be similar to embodiment 1, difference is, angle between the top of first flexible sealing fin 11 and the diaphragm seal 6 is 40 °, angle between the top of second flexible sealing fin 12 and the diaphragm seal 6 is 60 °, and it is the round-corner transition of 10mm that the bending part of described flexible sealing fin adopts radius.

Embodiment 3

A kind of axial seal structure is similar to embodiment 1, and difference is that the top of first flexible sealing fin 11 and second flexible sealing fin 12 contacts with axial sealing plate 5.

The seal form of this structure, real machine check, effect is fine, 300,000 above units cooperate the design of employing double sealing, air leak rate of air curtain can be controlled at about 4%, can keep 1 year left and right sides air leak rate of air curtain ascensional range less than 1%, initial operating stage transmission electric current rises to some extent, but a week back running current promptly drops to level identical when being unkitted flexible sealing fin.The utility model can use on new design air preheater, also can use on rebuilding old equipment.Drop into not quite, it is convenient to implement, and it is good to produce effects.

Claims

1. an air preheater pulls the shape hermetically-sealed construction, comprise by bolt (10) and nut (9) and be fixedly connected on the radially diaphragm seal (6) of dividing plate (2) one ends, be provided with pressing plate (8) between nut (9) and the diaphragm seal (6), it is characterized in that, the flexible sealing fin that also comprises at least one bending shape, the bottom of flexible sealing fin is located at diaphragm seal (6) and radially between the dividing plate (2), the top of flexible sealing fin contacts with fanning strip (4) or axial sealing plate (5).

2. air preheater towing shape hermetically-sealed construction as claimed in claim 1, it is characterized in that, the flexible sealing fin one of described bending shape has two, be respectively first flexible sealing fin (11) and second flexible sealing fin (12), the bottom of first flexible sealing fin (11) and second flexible sealing fin (12) is located at diaphragm seal (6) and radially between the dividing plate (2) successively, angle between the top of first flexible sealing fin (11) and the diaphragm seal (6) is 20-40 °, and the angle between the top of second flexible sealing fin (12) and the diaphragm seal (6) is 30-60 °.

3. air preheater towing shape hermetically-sealed construction as claimed in claim 1 is characterized in that it is the round-corner transition of 5-10mm that the bending part of described flexible sealing fin adopts radius.