Compressor Seal Fin Layout to Suppress Jet-Flow Gas Leakage
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Solution Overview
Problem
In existing sealing devices for compressors, process gas leaks occur due to jet flow penetration through the second fin group, leading to gas leakage from the intra-compressor side.
Innovation Solution
A sealing device design that includes a ring part with first, second, and third fin groups, where the process gas and inert gas form clearances to suppress leakage by guiding the jet flow away from the second fin group using a vortex and stepped surfaces, ensuring the process gas does not penetrate the second fin group clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If process gas is supplied to the first fin group as sealing gas, then sealing performance is improved, but jet flow penetrates the second fin group causing gas leakage
Solution Approach 1:
The sealing device is divided into multiple functional segments: first fin group for initial sealing, second fin group for secondary sealing, and third fin group for final sealing. This segmentation allows each fin group to perform its specific sealing function while preventing jet flow penetration through the entire sealing structure.
Solution Approach 2:
Inert gas is introduced as an intermediary substance between the process gas and the external environment. The inert gas forms a protective barrier in the second fin group clearance, preventing the process gas jet flow from penetrating through and leaking to the outside.
2Ease of operation
If clearance is formed between fin groups and rotary shaft, then sealing gas flow is enabled, but jet flow penetrates through the clearance
Solution Approach 1:
Different fin groups are designed with different local characteristics: the first fin group has a specific clearance for process gas sealing, the second fin group has clearance for inert gas flow and jet flow redirection, and the third fin group has clearance for final sealing. Each clearance is optimized for its specific local function.
Solution Approach 2:
The solution redirects the jet flow from a radial path (directly through the second fin group clearance) to an axial path (along the rotary shaft surface). This dimensional change in flow direction prevents penetration while maintaining the necessary radial clearance for sealing gas flow.
3Reliability
If inert gas is supplied to the second fin group, then sealing is enhanced, but mixed gas discharge is required
Solution Approach 1:
The discharge channels for process gas and inert gas are merged into a single mixed gas discharge system. The third fin group creates a common discharge path where both gases are discharged together, simplifying the discharge structure while maintaining the sealing enhancement benefits of inert gas.
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
Effectively suppresses intra-compressor gas leakage by guiding the jet flow radially outward, preventing direct collision with the second fin group and reducing the likelihood of gas escaping the compressor, even with combustible or toxic gases like NOX.
Implementation Method 1
the process gas that has passed through the first fin group forms a vortex while flowing toward the second fin group
Implementation Method 2
Each of the first fin group and the second fin group forms a clearance together with the outer peripheral surface of a rotary shaft
Data Source
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AI summary
The present invention includes a ring part (60), a first fin group (81) that together with a first outer peripheral surface (21) forms a clearance, and a second fin group (83) of which the front end is positioned farther radially inward than the first outer peripheral surface (21) and which together with a second outer peripheral surface (22) forms a clearance. The ring part (60) has a first gas supply channel (76) capable of supplying a first sealing gas to the first fin group (81), a second gas supply channel (77) capable of supplying a second sealing gas to the second fin group (83), and a mixed gas discharge channel (78) capable of discharging a mixed gas of the first sealing gas and the second sealing gas from between the first fin group (81) and the second fin group (83).