Brush Seal Stress-Accommodating Membrane for High-Temperature Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seals in regenerative air preheaters, such as metal strip seals and brush seals with plate-type membranes, face issues with wear, deformation, and leakage due to high temperatures and corrosive environments, leading to inefficient heat transfer and increased CO2 emissions.
Innovation Solution
A brush seal with a thin, flexible, and stress-accommodating membrane embedded between bristles, made of temperature-resistant materials, that can withstand high temperatures and accommodate stress and deflection through overlapping and deformable construction, ensuring effective sealing over multiple maintenance cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal strip seals are used to prevent flue gas leakage, then sealing is provided, but the seals wear due to frictional contact and thermal expansion causes gap fluctuations leading to leakage
Solution Approach 1:
The patent uses a flexible membrane seal that can deflect and conform to gap variations caused by thermal expansion, unlike rigid metal strip seals. The membrane flexes to maintain contact sealing across fluctuating gaps, preventing leakage while accommodating dimensional changes in the preheater structure.
Solution Approach 2:
The membrane seal is designed to be dynamic and adaptable, allowing it to move and deflect in response to changing operational conditions including thermal expansion and contraction. This dynamic behavior enables the seal to maintain effectiveness throughout its service life despite environmental variations.
2Reliability
If plate-type membranes are used in brush seals, then sealing is improved, but the membranes are prone to wear and permanent deformation or breakage under stress
Solution Approach 1:
The patent employs a flexible membrane that can deflect and conform to the brush bristle structure, providing sealing performance while accommodating stress through flexibility rather than rigidity. This flexible design prevents permanent deformation and breakage under operational stresses.
Solution Approach 2:
The membrane is constructed as a composite structure combining multiple layers including a flexible base material with reinforcing elements, creating a material that is both durable and flexible. This composite construction provides tear resistance and durability while maintaining the flexibility needed to accommodate brush bristle movement and stress.
3Strength
If thicker membranes are used to support brush bristles, then structural support is improved, but the membranes become prone to wear and breakage under stress
Solution Approach 1:
The patent uses a composite membrane structure with multiple layers including a flexible base material and reinforcing elements. This composite construction provides the necessary strength to support brush bristles while maintaining flexibility and resistance to wear and breakage, achieving both structural support and durability.
Solution Approach 2:
The membrane features localized reinforcement at critical stress points while maintaining flexibility in other areas. This local quality approach provides bristle support capability where needed while preventing overall membrane breakage under stress through strategic reinforcement rather than uniform thickness increase.
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 brush seal provides improved sealing reliability and longevity, reducing flue gas leakage, maintaining efficiency, and minimizing CO2 emissions by withstanding high temperatures and operational stresses, while allowing for easy installation and maintenance.
Implementation Method 1
the sealing membrane can be made of a relatively thin material, such as a material having a thickness less than bristle width or diameter. Sealing membrane is of a longitudinally extensible construction helping to accommodate stress and/or deflection
Implementation Method 2
Sealing membrane and the bristles are made of a material capable of withstanding 700° Fahrenheit for high temperature use
Data Source
AI summary
A brush seal usable in high temperature sealing applications having brush bristles and a sealing membrane of stress and deflection accommodating construction capable of longitudinal extensibility. Sealing membrane has one portion slidably overlapped with another portion. In one embodiment, membrane is folded over itself providing slidable overlapping in one direction and is formed of overlapping membrane sheets providing slidable overlapping in another direction. In another embodiment, membrane has spaced apart deformation regions providing longitudinal extensibility in accommodating stress and/or deflection. Membrane can be made of metallic foil having a thickness no greater than brush bristle width or diameter and is embeddable in bristles of the brush seal.