Dual-Zone Labyrinth Sealing for Oxygen-Rich Turbomachines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Labyrinth seals in turbomachinery face challenges when used with oxygen-rich process fluids, as they risk ignition due to material reactivity and potential spark generation from thin edges, and existing designs are not mechanically robust enough to handle such environments safely.
Innovation Solution
A dual-zone labyrinth seal design is implemented, where teeth on the stator are made of non-flammable materials in the oxygen-rich zone and teeth on the rotor are made of more flammable materials in the non-oxygen-rich zone, using compatible materials like brass and stainless steel respectively, with separate gas streams to minimize ignition risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional labyrinth seal design with thin-edged teeth is used in oxygen-rich environment, then sealing effectiveness is improved, but ignition risk increases due to material reactivity and spark generation
Solution Approach 1:
The patent applies local quality by making the seal teeth in the oxygen-rich zone have rounded edges and using non-flammable materials specifically in that zone, while other zones can use different material properties. This localized adaptation ensures safety in the oxygen-rich environment without compromising sealing effectiveness throughout the entire seal structure.
Solution Approach 2:
The patent introduces a buffer gas (inert atmosphere) in the second sealing zone that is less reactive than oxygen. This buffer gas creates a safer environment for the seal teeth, reducing the ignition risk while maintaining the necessary sealing function. The buffer gas acts as an intermediary between the oxygen-rich process gas and the seal teeth.
2Strength
If stator and rotor are made of different materials for mechanical reasons, then mechanical performance is improved, but spark generation risk increases at material interfaces
Solution Approach 1:
The patent applies local quality by specifying that in the oxygen-rich zone, both stator and rotor teeth shall be made of non-flammable materials with rounded edges, while other zones can use different material combinations for optimal mechanical performance. This localized material selection prevents sparks at material interfaces in the critical oxygen-rich zone while maintaining overall mechanical performance.
3Reliability
If thin-edged teeth are used to reduce leakage, then sealing performance is improved, but heat absorption increases leading to faster ignition
Solution Approach 1:
The patent applies local quality by rounding the edges of seal teeth specifically in the oxygen-rich zone where heat absorption is most critical, while maintaining sharp edges in other zones for optimal sealing performance. The rounded edges in the oxygen-rich zone reduce the surface area that absorbs heat, thereby slowing the rate at which ignition temperature is reached.
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 effectively prevents leakage and minimizes ignition hazards in oxygen-rich environments by utilizing materials and gas streams that are compatible with the specific zones, ensuring mechanical robustness and safety.
Implementation Method 1
Torturous gas flow path through teeth induces a pressure drop and restricts leakage
Implementation Method 2
Torturous gas flow path through teeth induces a pressure drop and restricts leakage
Implementation Method 3
introducing a buffer gas into the second sealing zone... using compatible materials like brass and stainless steel respectively, with separate gas streams to minimize ignition risks
Data Source
AI summary
A method for sealing an oxygen-rich process gas within a compressor or expander, including providing a rotor component having a rotating element and providing a stator component having a stationary element. Introducing a seal gas into the first sealing zone and introducing a buffer gas into the second sealing zone. Wherein at least a portion of the rotating element includes the teeth of a first labyrinth seal. Wherein the first labyrinth seal is part of a first sealing zone. Wherein at least a portion of the stationary element includes the teeth of a second labyrinth seal. And wherein the second labyrinth seal is part of a second sealing zone.