Bellows Bleed Valve Without Sliding Seals for High-Pressure Turbines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bleed valves in gas turbine engines face challenges with high-pressure and temperature limitations, as well as rapid degradation of carbon seals, necessitating frequent maintenance and replacement.
Innovation Solution
A bleed valve design featuring a high-pressure cavity and valve housing with a bellows system that uses pressurized fluids to control the expansion and compression of the bellows, eliminating the need for dynamic sliding seals, and incorporating a system poppet and shaft to seal the valve seat, with a configuration that allows for controlled operation by a pilot or flight computer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If carbon seals are used as dynamic sliding sealing mechanism, then the bleed valve can be operated, but the seals wear and degrade quickly requiring regular replacement
Solution Approach 1:
The patent removes the carbon seal component entirely from the system. Instead of using a dynamic sliding seal, the invention employs a bellows-actuated system where the valve stem is directly connected to the bellows without requiring any sealing mechanism against the valve body, thus eliminating the reliability issue of seal degradation
Solution Approach 2:
The patent replaces the mechanical sliding seal system with a bellows-based pneumatic actuation system. The bellows expands and contracts to open and close the valve, eliminating the need for continuous sliding contact and associated sealing requirements
2Ease of operation
If conventional carbon seals are used, then the valve can function, but they have temperature limitations and fail under high temperature conditions
Solution Approach 1:
The patent removes the temperature-sensitive carbon seal component from the system, replacing it with a bellows mechanism that has no material temperature limitations, thereby enabling the valve to function reliably under high temperature conditions
Solution Approach 2:
The invention changes the operating parameters of the sealing system by eliminating the need for sliding contact seals entirely, allowing the valve to operate in high temperature environments where conventional carbon seals would fail
3Ease of operation
If the bellows is maintained in expanded position during operation, then the valve can open and close, but vibrations have greater impact reducing reliability
Solution Approach 1:
The patent employs a dynamic bellows system that can change its state based on operational requirements. The bellows is designed to be collapsible, allowing it to transition between expanded (valve open) and compressed (valve closed) states, with the ability to be maintained in a compressed state during normal operation to minimize vibration impact
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances the durability and reliability of the bleed valve by minimizing the force required to maintain the valve in a closed position, reducing the risk of failure, and extending the lifespan by maintaining the bellows in a compressed, nested state during operation, thus reducing the impact of vibrations and improving performance under high-pressure conditions.
Implementation Method 1
the bellows expands in response to a pressure differential between an interior of the bellows and an exterior of the bellows
Implementation Method 2
a bellows for alternatively capturing and releasing one or more pressurized fluids
Implementation Method 3
at least one servo air port configured to inject a second of the one or more pressurized fluids directly into the interior volume of the bellows, so as to exert a second pressure against the interior surface of the bellows, thereby expanding the bellows
Implementation Method 4
at least one cavity air port configured to inject a first of the one or more pressurized fluids into the interior volume of the high-pressure cavity about the exterior surface of the bellows, so as to exert a first pressure against the exterior surface of the bellows, thereby compressing the bellows
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A bleed valve for use in a gas turbine engine of an aircraft includes a high-pressure cavity coupled to a valve housing, which includes a valve seat configured to be sealed by a system poppet. The system poppet is operably coupled to a shaft that is itself coupled to a movable end of a bellows, which is positioned within the high-pressure cavity. The opening and closing of the valve is controlled by at least one cavity air port that is configured to inject a first fluid into the high-pressure cavity, thus compressing the bellows, and by a servo air port that is configured to inject a second fluid directly into the bellows, to expand it.