A starting air valve airflow filtering device

Abstract

This invention belongs to the field of accessories for aero-engine starting subsystems and discloses an airflow filtering device for a starting air valve. The device includes a leading edge, a main body, and a particle separation section. Airflow passes through the conical leading edge and flows rearward along both sides of the main body. The particle separation section is located at the rear of the main body. In this section, an aerodynamic configuration separates the air from the particles within it. The particle separation section has an airflow inlet that communicates with the interior of the main body, and the air inlet direction of the particle separation section faces rearward. This airflow filtering device has a simple structure, is easy to install, and requires less frequent replacement, thus reducing manufacturing costs. Furthermore, this airflow filtering device effectively prevents wear and contamination of the starting air valve components by particles in the airflow, which helps improve the lifespan and reliability of the starting air valve.

Description

Technical Field

[0001] This invention belongs to the field of aircraft engine starting subsystem accessories, and relates to an airflow filtering device, specifically a starting air valve airflow filtering device. Background Technology

[0002] During aircraft engine startup, an air turbine starter typically drives the engine to cold start. When sufficient air flows into the engine, fuel is ignited in the combustion chamber to start the engine. Without a starter to drive the engine to cold start, the engine will not start properly. The compressed air from the starter is controlled and regulated by a starter air valve, which is now commonly a pneumatic butterfly valve.

[0003] Typically, a probe is installed within the starting air valve passage, directing the airflow through the passage towards the valve for pneumatic control. However, the air entering the starting air valve may contain various particles, dirt, and other contaminants. As the air is introduced into components within the valve, such as exhaust ports, actuators, and springs, these particles can accumulate, reducing valve performance and increasing maintenance frequency. To reduce particulate contamination, an airflow filter is usually installed downstream of or inside the probe. The most common type is a porous filter, such as a metal mesh or sintered metal powder embedded within the probe. These porous filters are prone to clogging, have a limited lifespan, and require frequent probe replacement. Other types of filters include downstream-facing filter probes. While these filters do not require frequent replacement, their intake efficiency is lower and they are not highly efficient in practical applications. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a starter air valve airflow filtering device. This filtering device separates air and particles through a pneumatic configuration, exhibiting high intake efficiency, a simple structure, and requiring no frequent replacement. It effectively prevents wear and contamination of the starter air valve components by airborne particles, thereby improving the lifespan and reliability of the starter air valve and providing a reliable guarantee for the start-up of aircraft engines.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An airflow filtering device for a starting air valve includes a leading edge, a main body, and a particle separation section. Airflow passes through the conical leading edge and flows backward along both sides of the main body. The particle separation section is located at the rear of the main body. In the particle separation section, the air and particles therein are separated by the pneumatic configuration of the section. The particle separation section is provided with an airflow inlet and communicates with the interior of the main body. The air inlet direction of the particle separation section is rearward.

[0007] Furthermore, the airflow filtration device is axisymmetric in that the leading edge, the main body, and the particle separation section are symmetrical about the central axis.

[0008] Furthermore, the airflow filtering device of the starting air valve is a cylindrical structure with an elongated fish-shaped cross-section. The leading edge is a conical structure at the front end, which separates the airflow into two streams. The main body is the middle section of the fish-shaped cross-section, with a cavity in the middle and the upper end connected to the inside of the starting air valve. The particle separation section is the turning part and tail of the fish-shaped cross-section. The rear opening of the particle separation section forms an air inlet, which is connected to the cavity of the main body.

[0009] Furthermore, the leading edge angle of attack ranges from 40° to 60°.

[0010] Furthermore, after the airflow containing particles passes through the particle separation section, the particles with greater inertia continue to move along their trajectory under the guidance of the fishtail-shaped particle separation section. The airflow enters the main body through the air inlet under the action of the pressure difference inside and outside the starting air valve, and then flows into the interior of the starting air valve.

[0011] Furthermore, the contraction ratio of the particle separation section is the ratio of the inlet area to the throat area, and the throat is the narrowest part of the fishtail shape of the particle separation section; the contraction ratio is adjusted by controlling the radius R of the fishtail-shaped arc of the particle separation section.

[0012] Furthermore, the shrinkage ratio of the particle separation section is 3 to 5.

[0013] Furthermore, the thickness range between the inner and outer surfaces of the leading edge, the main body, and the particle separation section is 1–2 mm.

[0014] Furthermore, the inner surface of the particle separation section forms a contraction channel along the airflow direction. After the airflow enters the interior of the particle separation section from the air inlet, it will accelerate under the compression of the contraction channel until it enters the cavity inside the main body.

[0015] Furthermore, the airflow filtering device for the starting air valve is installed inside the starting air valve channel perpendicular to the airflow direction, with its leading edge facing the starting air valve inlet and the particle separation section facing the starting air valve outlet.

[0016] Beneficial effects:

[0017] 1. Compared with the prior art, the starting air valve airflow filtering device provided by the present invention makes full use of pneumatic principles, has a simple structure, low maintenance and manufacturing costs, and is easy to implement in engineering.

[0018] 2. By separating air and particles through aerodynamic configuration, it has high air intake efficiency and can effectively avoid wear and contamination of the starting air valve components by air particles, thereby improving the life and reliability of the starting air valve and providing reliable guarantee for the starting of aircraft engines.

[0019] 3. This invention does not use filters or other parts that require replacement and maintenance, ensuring that the air intake efficiency remains unchanged during long-term use. In addition, it controls the cost of use and ensures the service life. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the airflow filtering device for the starting air valve;

[0022] Figure 2 This is a specific implementation case diagram of the starter air valve airflow filtering device;

[0023] Among them, 1—leading edge, 2—main body, 3—particle separation section, 4—airflow, 5—particle, 6—particle trajectory. Detailed Implementation

[0024] This section describes embodiments of the present invention, used to explain and illustrate the technical solutions of the present invention. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating directions or positional relationships, are given in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include more than one of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] An airflow filtering device for a starting air valve includes a leading edge 1, a main body 2, and a particle separation section 3. Airflow passes through the conical leading edge 1 and flows backward along both sides of the main body 2. The particle separation section 3 is located in the rear section of the main body 2. The air and particles in the particle separation section 3 are separated by the pneumatic configuration of the section. The particle separation section 3 is provided with an airflow inlet and communicates with the interior of the main body 2. The air inlet direction of the particle separation section 3 is rearward.

[0028] The airflow filtration device has an axisymmetric configuration, specifically, the leading edge 1, the main body 2, and the particle separation section 3 are symmetrical with respect to the central axis.

[0029] The starting air valve airflow filtering device is a cylindrical structure with an elongated fish-shaped cross-section. The front edge 1 is a conical structure at the front end, which separates the airflow into two sides. The main body 2 is the middle section of the fish-shaped cross-section. The middle of the main body 2 is a cavity and the upper end is connected to the inside of the starting air valve. The particle separation section 3 is the turning part and tail of the fish-shaped cross-section. The rear opening of the particle separation section 3 forms an air inlet, which is connected to the cavity of the main body 2.

[0030] The angle of attack range of the leading edge 1 is 40° to 60°.

[0031] When the airflow 4 containing particles 5 passes through the particle separation section 3, the particles 5, which have greater inertia, continue to move along the particle motion trajectory 6 under the guidance of the fishtail-shaped particle separation section 3. The airflow 4 enters the main body 2 through the air inlet under the action of the pressure difference inside and outside the starting air valve, and then flows into the interior of the starting air valve.

[0032] The contraction ratio of particle separation section 3 is the ratio of the inlet area to the throat area. The throat is the narrowest part of the fishtail shape of particle separation section 3. The contraction ratio is adjusted by controlling the radius R of the fishtail-shaped arc of particle separation section 3.

[0033] The shrinkage ratio of particle separation section 3 is 3 to 5.

[0034] The thickness between the inner and outer surfaces of the main body 2 and the particle separation section 3 ranges from 1 to 2 mm.

[0035] The inner surface of the particle separation section 3 forms a contraction channel along the airflow direction. After the airflow 4 enters the interior of the particle separation section 3 from the air inlet, it will accelerate under the compression of the contraction channel until it enters the cavity inside the main body 2.

[0036] The airflow filtering device for the starting air valve is installed inside the starting air valve channel perpendicular to the airflow direction. During installation, the leading edge 1 faces the starting air valve inlet, and the particle separation section 3 faces the starting air valve outlet.

[0037] The overall configuration of the device is generated by stretching it perpendicular to the surface to an appropriate length.

[0038] The smaller the radius R of the arc of the particle separation section 3, the greater the contraction ratio, and the greater the centripetal force of the particle 5. At this time, the particle 5 moves along the particle trajectory 6 under the combined action of inertial force and centripetal force, which can achieve the effect of separating even smaller particles 5 from the airflow 4.

[0039] The working principle of the above technical solution is as follows: When the airflow containing particles passes through the particle separation section, particles with greater inertia continue to move along their trajectory. Under the action of the internal and external pressure difference, the airflow enters the main body of the airflow filtration device and then flows into the starting air valve. The contraction ratio of the particle separation section can be adjusted by the radius R of the arc of the particle separation section. The smaller R is, the larger the contraction ratio and the greater the centripetal force of the particle motion. At this time, the particles move along their trajectory under the combined action of inertial force and centripetal force, which can achieve the effect of separating smaller particles from the airflow. On the other hand, the inner surface of the particle separation section forms a contraction channel along the airflow direction. After the airflow enters the particle separation section, it will accelerate until it enters the main body and then flows into the starting air valve, improving the intake efficiency.

[0040] Figure 2 An embodiment of an airflow filtering device for a starting air valve is provided. The airflow filtering device is installed within the valve body channel, with its leading edge 1 facing the starting air valve inlet and the particle separation section 3 facing the starting air valve outlet. Please refer to... Figure 2 As shown, when the pneumatic solenoid valve is energized, the airflow 4 enters the starting air valve through the airflow filter. The particles 5 mixed in the airflow 4 move along the particle trajectory 6 under the combined force of inertial force and centripetal force through the particle separation section 3 of the airflow filter. The airflow 4 enters the upper actuation chamber of the actuation mechanism through the pneumatic solenoid valve and the rate control device, and acts on the piston in the actuation chamber. The pneumatic force pushes the piston downward, thereby driving the butterfly plate to open.

[0041] The airflow filtration device provided in this embodiment has a simple structure and low maintenance and manufacturing costs. It effectively avoids the wear and contamination of the starting air valve components by air particles, and at the same time has higher air intake efficiency, providing a practical airflow filtration device for the starting air valve.

[0042] Furthermore, there are many specific methods and approaches to implement this invention, and the above description is only a preferred embodiment of this invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A starting air valve airflow filtering device, characterized in that, It includes a leading edge (1), a main body (2) and a particle separation section (3). The airflow passes through the conical leading edge (1) and flows backward along both sides of the main body (2). The particle separation section (3) is located at the rear of the main body (2). In the particle separation section (3), the air and the particles therein are separated by the aerodynamic configuration of the section. The particle separation section (3) is provided with an airflow inlet and is connected to the interior of the main body. The airflow inlet of the particle separation section (3) faces backward. The starting air valve airflow filtering device is a cylindrical structure with an elongated fish-shaped cross section. The leading edge (1) is located at the front end and is a conical structure that separates the airflow into two streams. The main body (2) is the middle section of the fish-shaped cross section. The middle of the main body (2) is a cavity and the upper end is connected to the interior of the starting air valve. The particle separation section (3) is the turning part and the tail of the fish-shaped cross section. The rear opening of the particle separation section (3) forms an air inlet, which is connected to the cavity of the main body (2). The angle of attack of the leading edge (1) is 40°~60°. When the airflow (4) containing particles (5) passes through the particle separation section (3), the particles (5) with greater inertia continue to move along the particle trajectory (6) under the guidance of the fishtail-shaped particle separation section (3). The airflow (4) enters the main body (2) through the air inlet under the action of the pressure difference between the inside and outside of the starting air valve, and then flows into the inside of the starting air valve. The contraction ratio of the particle separation section (3) is the ratio of the area of ​​the air inlet to the area of ​​the throat. The throat is the narrowest part of the fishtail shape of the particle separation section (3). The contraction ratio is adjusted by controlling the radius R of the fishtail-shaped arc of the particle separation section (3).

2. The starting air valve airflow filtering device according to claim 1, characterized in that, The airflow filtration device is axisymmetric in that the leading edge (1), the main body (2) and the particle separation section (3) are symmetrical about the central axis.

3. The airflow filtering device for a starting air valve according to claim 1, characterized in that, The shrinkage ratio of the particle separation section (3) is 3~5.

4. The airflow filtering device for a starting air valve according to claim 1, characterized in that, The thickness range between the inner and outer surfaces of the leading edge (1), the main body (2) and the particle separation section (3) is 1~2mm.

5. The airflow filtering device for a starting air valve according to claim 1, characterized in that, The inner surface of the particle separation section (3) forms a contraction channel along the airflow direction. After the airflow (4) enters the interior of the particle separation section (3) from the air inlet, it will accelerate under the compression of the contraction channel until it enters the cavity inside the main body (2).

6. The airflow filtering device for a starting air valve according to claim 1, characterized in that, The airflow filter device for the starting air valve is installed inside the starting air valve channel perpendicular to the airflow direction. When installed, the leading edge (1) faces the starting air valve inlet, and the particle separation section (3) faces the starting air valve outlet.

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