Dual-Zone Labyrinth Seal for Oxygen-Rich Turbomachinery
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Solution Overview
Problem
Labyrinth seal designs for turbomachinery face challenges in preventing leakage and ignition risks when operating with oxygen-rich process fluids, particularly due to potential spark generation from thin edges and material incompatibilities.
Innovation Solution
A dual-zone labyrinth seal design is implemented, with teeth on the stator made of non-flammable materials in the oxygen-rich zone and teeth on the rotor made of more flammable materials in the non-oxygen-rich zone, using compatible materials like brass and stainless steel respectively, to minimize ignition risks and enhance mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thin-edged teeth are used in labyrinth seals for air/nitrogen service, then leakage prevention is improved, but ignition risk increases in oxygen-rich environments
Solution Approach 1:
The patent applies different material properties to different parts of the seal system. The stator teeth are made from non-flammable materials (brass, copper, or aluminum alloys) while the rotor teeth can use different materials. This local differentiation of material properties allows the seal to prevent leakage effectively while eliminating ignition risk in the oxygen-rich environment where the stator teeth are located.
Solution Approach 2:
The patent creates an inherently safe environment by using non-flammable materials for the stator teeth that interface with the oxygen-rich process gas. These materials do not support combustion, effectively creating a non-ignitable environment at the critical interface between the seal and the oxygen-rich fluid, thus preventing ignition even if thin edges are present.
2Stability of the object's composition
If stator and rotor are made of different materials, then mechanical stability is improved, but spark generation risk increases due to material incompatibility
Solution Approach 1:
By making the stator teeth from non-flammable materials such as brass, copper, or aluminum alloys, the patent creates an inherently safe environment that prevents spark generation and ignition. These materials do not combust and are resistant to sparking, eliminating the harmful effect of spark generation while maintaining the necessary material differentiation between stator and rotor for mechanical stability.
3Reliability
If thin edges are used in labyrinth seal teeth, then sealing effectiveness is improved, but heat absorption increases leading to faster ignition
Solution Approach 1:
The patent applies non-flammable materials specifically to the stator teeth that have thin edges and are exposed to oxygen-rich process gas. This local application of fire-resistant material properties to the critical sealing surfaces maintains sealing effectiveness while preventing the thin edges from absorbing heat and reaching ignition temperature, as the non-flammable materials do not combust even when heated.
4Reliability
If traditional labyrinth seal design is used, then leakage control is achieved, but mechanical instability may occur due to stress forces
Solution Approach 1:
The patent changes the material parameters of the stator teeth from traditional steel to non-flammable materials such as brass, copper, or aluminum alloys. This parameter change in material composition maintains the structural integrity and mechanical stability of the seal while preventing combustion. The design also optimizes tooth geometry parameters to balance leakage control performance with mechanical stability requirements.
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 reduces the risk of ignition in oxygen-rich environments by segregating zones based on material compatibility and ensuring safe operation of turbomachinery.
Implementation Method 1
Torturous gas flow path through teeth induces a pressure drop and restricts leakage
Implementation Method 2
thin edges adsorb heat energy faster and therefore reach ignition temperature faster than larger flat surfaces
Data Source
AI summary
A gas seal to seal an oxygen-rich process gas within a compressor or expander, including a rotor component having a rotating element and a stator component having a stationary element. 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. Wherein the second labyrinth seal is part of a second sealing zone.