WO2020256678A2

WO2020256678A2 - A brush seal

Info

Publication number: WO2020256678A2
Application number: PCT/TR2020/050534
Authority: WO
Inventors: Mahmut Faruk Aksit; Sadik HAZER
Original assignee: Turbin Arge Ve Muhendislik Anonim Sirketi
Priority date: 2019-06-21
Filing date: 2020-06-22
Publication date: 2020-12-24
Also published as: WO2020256678A3; EP3987201A4; EP3987201A2

Abstract

The present invention relates to a brush seal (1) which provides sealing between the high pressure regions and the low pressure regions around the shafts which rotate at high speed and particularly provided in turbo machines like airplane motors, vapor turbines and gas turbines, and which increases performance and which is compliant to different diameters thanks to the flexible structure thereof in circular direction and which comprises fibers (2) which provide sealing by forming a surface which prevents flow. The subject matter brush seal (1) is characterized by comprising at least two plates (4) which have notched structure and between which the bunches, formed by fibers (2), are fixed in the form of sandwich; notches (5) provided on the notched plates (4) and which provide freedom to the notched plates (4) in the direction of circular bending; extension regions (6) which have plate (4) parts which remain between the notches (5).

Description

A BRUSH SEAL

SPECIFICATION

TECHNICAL FIELD

The present invention relates to a brush seal, which provides sealing between the high pressure regions and the low pressure regions around the shafts which rotate at high speed and particularly provided in turbo machines like airplane motors, vapor turbines and gas turbines, and which increases performance.

KNOWN STATE OF THE ART

In the known art, high energy flow, which comes from the high pressure region and which flows to the low pressure region, normally hits the turbine wings and it is transformed into mechanical energy. However, a small gap is left between the fixed wings and the shaft or between the rotary wings and the body for tolerating the assembly tolerances, the instantaneous part movements based on impacts and thermal expansions. Since the high energy flow can pass through these gaps in an easier manner, it is guided to these regions and is discharged outwards without realizing any work. Therefore, losses which may amount to the vicinity of 2% may occur in the total turbine. When the total capacities of turbines are considered, the yearly costs of losses exceed millions of dollars.

The elements, used for preventing these losses, are honeycomb sealing elements, labyrinth seals or brush seals. The labyrinth seals which are most frequently used among these elements create turbulence in the flow by means of the teeth existing thereon, and they are the sealing elements which decrease leakage flows. However, the best sealing element type in the known art is brush seal which provides 90% better performance when compared with labyrinth seals. Brush seals are a leakage flow performance system formed by special alloyed fibers arranged at a specific inclination angle when compared with the long edge of the plate where it is fixed, and high technology must be used as the material and design in production of brush seals since they operate at high temperature and at high pressure because of their positions. Moreover, since they operate at specific steps of the shaft which exists in turbo machines, they are designed and used at different diameters nearly for all different applications. Brush seals are used for increasing efficiency in various turbo machines particularly in gas turbines and in vapor turbines. The design and applications of brush seals include substantially detailed and precise calculations and procedures since they operate under high temperature and pressure and because of the probable sensitivities of these wires against these conditions. Various parameters like fiber diameter, density, length, material, production fixture characteristics and method for welding the fibers to the plate must be designed and produced in an optimal manner. Therefore, brush seals are produced by using very precise methods.

Brush seals are used at different positions in a turbo machine and usually the diameters of the shaft surface where the brush seals contact are not the same as each other. Because of diameter change, each brush seal is produced by means of production fixtures which are specific for the related shaft diameter, and a standard mass production method cannot be applied. Therefore, production costs increase substantially, and when the profit cost balance is considered, the applicability of brush seals is not suitable in some cases.

In the patent application with number US6431827 which exists in the literature, a brush seal used in steam turbines is disclosed. In the invention described in said document, there is a diaphragm and, there is a recess in ring form formed by deep and non-deep recesses and this recess is opened into a non-deep recess. Pin part/brush seal is placed into the recess. The brush seal comprises a couple of flexible rods fixed to the proximal ends of the brush hairs by means of welding and it enters into the flat recess and is placed to a recess existing on the axial face of the pin part. In the pin part, there are base parts which extend inside the deep recess. The brush seal/pin part combination compresses the diaphragm material to the pin part/brush seal combination and fixes into the ring recess. The brush seal can be used by means of diaphragm recesses and pin parts with different diameters. However, in said invention, bending of the seals cannot be sufficiently provided since there is no special structure which provides flexibility, and the brush seal developed by means of said invention is used only for fixing fibers by means of thick plates. Therefore, the invention, described in said document, is insufficient in fixation of fibers by means of a thinner and more flexible structure.

In the patent application documents with numbers US6431827 and US20150361815 which exist in the literature, placement of brush seals between front and rear plaques is described. In the inventions described in said documents, the brush seals exist as a thicker structure, and the fixation of fibers by means of a thinner and flexible structure is not possible.

As a result, because of all of the abovementioned problems and because of the insufficiency of the present solutions, an improvement is required in the related technical field. OBJECT OF THE INVENTION

The present invention relates to a brush seal which is compliant to different diameters, for eliminating the above mentioned disadvantages and for bringing new advantages to the related technical field.

The main object of the subject matter is to develop a brush seal which can be applied to different diameters without losing performance and robustness.

Another object of the present invention is to develop a brush seal which prevents performance problems since it is produced in a welded manner.

Another object of the present invention is to develop a brush seal where the same production elements can be used for different diameters and thus which can provide the same performance with low cost.

Another object of the present invention is to provide application to narrower places when compared with the present applications during assembly and application thanks to the thinner structure thereof. Particularly in labyrinth seals, the labyrinth teeth can be removed, and instead of this, production can be realized by means of application of brush seals in a thin structure.

In order to essentially reach said advantages, the present invention relates to a brush seal which provides sealing between the high pressure regions and the low pressure regions around the shafts which rotate at high speed and particularly provided in turbo machines like airplane motors, vapor turbines and gas turbines in energy sector, and which increases performance and which is compliant to different diameters thanks to the flexible structure thereof in circular direction and which comprises fibers which provide sealing by forming a surface which prevents flow. The present invention is characterized by comprising at least two plates which have notched structure and between which the bunches, formed by fibers, are fixed in the form of sandwich; notches provided on the notched plates and which provide freedom to the notched plates in the direction of circular bending; extension regions which have plate parts which remain between the notches.

The structural and characteristic properties and all advantages of the present invention have been described in a detailed manner by means of the below mentioned figures and by making reference to these figures. DESCRIPTION OF THE FIGURES

Figure 1 is an exemplary view of the subject matter brush seal.

Figure 2 is a frontal detailed view of the subject matter brush seal.

Figure 3 is a lateral perspective view of the subject matter brush seal.

Figure 4 is the views of the bended forms of the brush seal at different diameters.

Figure 5 is the view of the straight forms where the direction of the extensions and notches of the brush seal is different from the fiber angle.

Figure 6 is the view of the forms where the notches of the brush seal are embodied to be narrower and the extensions of the brush seal are embodied to be thicker.

Figure 7 is an alternative view of another embodiment of the extensions and notches of the brush seal.

Figure 8 is the view of the forms where the sharp corners of the extensions and the notches of the brush seal are eliminated in a manner preventing formation of cracks.

Figure 9 is an alternative view where the brush seal can be applied instead of labyrinth teeth on the labyrinth seal.

REFERENCE NUMBERS

1 . Brush seal

2. Fibers

3. Welding region

4. Plate

5. Notches

6. Extension regions

7. Labyrinth seal

8. Labyrinth tooth DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the preferred alternatives of the subject matter brush seal (1 ) are explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

In Figure 1 , an alternative embodiment of the subject matter brush seal (1 ) is given. Accordingly, the subject matter is a brush seal (1 ), which provides sealing between the high pressure regions and the low pressure regions around the shafts which rotate at high speed and particularly provided in turbo machines like airplane motors, vapor turbines and gas turbines, and which increases performance and which is compliant to different diameters thanks to the flexible structure thereof in circular direction, and comprises:

• fibers (2) which provide sealing by forming a surface which obstructs flow,

• at least two plates (4) with notched structure where the bunches, formed by fibers (2), are welded and fixed to the welding region in the form of sandwich,

• notches (5) provided on the notched plates (4) and which have a comb-like gapped structure and which provide freedom to the notched plates (4) in the bending direction,

• extension regions (6) provided between the notches (5) and which have a structure which is opposite to the arrangement direction and which prevent tightening of the fibers (2) in between and which provide assembly to the fixture and which have a plate structure.

In a preferred application of the present invention, the fibers (2) can be arranged and fixed with a specific inclination angle when compared with the long edge of the plates (4) with the desired diameter and density, and they can be placed between the two plates (4) with notched structure in an orthogonal manner when compared with the long edge of the plates

(4).

In another preferred application of the present invention, the notches (5) and the extension regions (6) have flat structure so as to be different from the arrangement angle. Thus, any intervention between the fibers (2) and the extension regions (6) is prevented. The notches

(5) and the extension regions (6) have a shape or angle which delimits the movement of the fibers (2) towards the gap between the extensions (6).

In another preferred application of the present invention, in case it is desired that the compression region of the fibers (2) is desired to be increased, the notches (5) are at a closer position to each other. This is provided by means of thickening the extension regions (6) and by means of narrowing the notches (5). Said extension regions (6) have been thickened towards the end region of fibers.

In another preferred application of the present invention, the extension regions (6) have inclined structure and are formed by means of narrowing the end parts of the notches (5). In the invention, there are preferably at least three extension regions (6).

In another preferred application of the present invention, the notches (5) are formed by rounding the deep parts thereof in a manner preventing formation of potential cracks which can begin from the sharp corners (Figure 8).

In another preferred application of the present invention, the two notched plates (4) can be the equivalent with each other, and in required cases, the two notched plates (4) comprise notches (5) and extension regions (6) having structures which are different from each other.

In an alternative application of the present invention, the extension regions (6) have been formed by narrowing the end parts of notches in a stepped manner.

In an alternative application of the present invention, the plates (4) are used which have notches (5) which are formed by shapes and lengths which are different from each other.

In an alternative embodiment of the present invention, the notches (5) have been formed only by cuts. In this case, the notches (5) have a non-gapped or partially non-gapped structure. In the bending direction, thanks to the cut notches (5), bending is provided by means of sliding the plate (4) parts on one another.

In an alternative application of the present invention, the brush seal (1 ) has been designed in a thin structure which can be directly applied to the regions where the labyrinth teeth (8) existing in the labyrinth seals (7) are provided. Thus, in the labyrinth seals (7) where the labyrinth teeth (8) are used in a changeable manner, one of these teeth can be removed and a brush seal (1 ) which is flexible and thin in a manner which can be applied instead can be used.

The operation principle of the present invention is as follows; The brush seal (1 ) which is the fiber type leakage flow performance system developed by means of the present invention can be compliant to different diameters thanks to the flexibility thereof in the circular direction. Notches (5) are formed on the notched plates (4) which are provided on the brush seal (1 ), and a comb-like structure is formed. After the notches (5) are formed, the plate parts which remain in between form the extension regions (6). Since said extension regions (6) are opposite to the arrangement direction of the fibers (2), compression process can be realized in a fixed manner without moving between the fibers (2). Thanks to the notches (5), flexibility is provided in the diameter change direction and thanks to this, although the brush seal (1 ) is produced in the form of a straight strip or at a specific diameter, it can be applied to different diameters thanks to the notches (5). Besides, since the same products are used at different diameters, the stock costs are lowered and a brush seal (1 ) is obtained which is substantially oriented to mass production.

Claims

1. A brush seal (1 ) which provides sealing between the high pressure regions and the low pressure regions around the shafts which rotate at high speed and particularly provided in turbo machines like airplane motors, vapor turbines and gas turbines, and which increases performance and which is compliant to different diameters thanks to the flexible structure thereof in circular direction and which comprises fibers (2) which provide sealing by forming a surface which prevents flow, wherein the subject matter brush seal (1 ) comprises at least two plates (4) which have notched structure and between which the bunches, formed by fibers (2), are fixed in the form of sandwich; notches (5) provided on the notched plates (4) and which provide freedom to the notched plates (4) in the direction of circular bending; extension regions (6) which have plate (4) parts which remain between the notches (5).

2. The brush seal (1 ) according to claim 1 , wherein fibers (2) are provided which can be arranged and fixed with a specific inclination angle or in an orthogonal manner with respect to the long edge of the plates (4) with the desired diameter and density and which can be placed between the two notched plates (4).

3. The brush seal (1 ) according to claim 1 , wherein extension regions (6) are provided which have an angle which is different from the arrangement angle of the fibers (2) and which prevent compression of the fibers (2) in between.

4. The brush seal (1 ) according to claim 1 , wherein said notches (5) have a comb-like gapped structure.

5. The brush seal (1 ) according to claim 1 , wherein at least two plates (4) with notched structure are provided where the bunches, which are formed by fibers (2) in between, are welded and fixed to the welding region (3).

6. The brush seal (1 ) according to claim 1 or 3, wherein the brush seal (1 ) preferably comprises three or more extension regions (6).

7. The brush seal (1 ) according to any one of the preceding claims, wherein the notches (5) and the extension regions (6) preferably have a shape or angle which will delimit the movement of the fibers (2) towards the gas between the extensions (6).

8. The brush seal (1 ) according to any one of the preceding claims, wherein in case the compression region of the fibers (2) is desired to be increased, there are thickened extension regions (6) and narrowed notches (5) towards the end region of the fibers.

9. The brush seal (1 ) according to any one of the preceding claims, wherein the subject matter brush seal (1 ) comprises notches (5) formed only by cuts.

10. The brush seal (1 ) according to any one of the preceding claims, wherein there are extension regions (6) which are formed by means of narrowing the end parts of the notches (5) in a stepped manner.

11. The brush seal (1 ) according to any one of the preceding claims, wherein the two notched plates (4) comprise notches (5) and extension regions (6) which are equivalent to each other or which are different from each other.

12. The brush seal (1 ) according to any one of the preceding claims, wherein the subject matter brush seal (1 ) comprises notches (5) with rounded deep parts.

13. The brush seal (1 ) according to any one of the preceding claims, wherein plates (4) are provided which have notches (5) formed by lengths and shapes which are different from each other.

14. The brush seal (1 ) according to any one of the preceding claims, wherein the subject matter brush seal (1 ) has thinness in a manner to be applied instead of labyrinth seal teeth.