Reciprocating Compressor Seal Assembly for Shutdown Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reciprocating compressor rod packing systems experience leakage during shutdown, leading to inefficiencies and potential environmental hazards due to their segmented design, which allows fluid to escape to the atmosphere, and existing solutions either fail to prevent leakage or result in premature wear of seals.
Innovation Solution
A seal assembly for reciprocating compressors featuring an unsegmented seal and a fluid passage with a valve to vent leaked fluid, combined with a bushing to reduce compressive load and a seal carrier to allow radial movement, effectively minimizing contact pressure and extending seal life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If segmented packing is used to allow wear, then the seal can withstand considerable wear over the life of operation, but leakage occurs during shutdown when the piston rod is static
Solution Approach 1:
The packing rings are designed to be movable relative to each other along the piston rod. During operation, the rings can shift position to maintain sealing contact. During shutdown, the rings automatically adjust to engage with the piston rod surface, preventing leakage. This dynamic adjustment capability allows the seal to adapt to different operational states while maintaining both wear resistance and sealing effectiveness.
2Reliability
If a single-piece seal like an O-ring is used to prevent leakage, then shutdown sealing is improved, but the seal wears out quickly due to inability to accommodate wear
Solution Approach 1:
The seal is divided into multiple segmented packing rings that can move independently relative to each other. Each segment can accommodate wear individually while maintaining the overall sealing function. The segments are held together by a retaining ring, allowing them to shift and adjust during both operation and shutdown to maintain sealing contact without premature wear.
3Duration of action of stationary object
If packing rings are made of numerous segments to allow wear, then wear resistance is improved, but leakage paths exist between segments allowing fluid to escape to atmosphere
Solution Approach 1:
The packing rings are designed with the ability to move axially along the piston rod while maintaining radial sealing contact. During shutdown, the rings automatically shift to engage with the piston rod surface, closing the leakage paths between segments. This dynamic positioning eliminates atmospheric leakage while preserving the wear-accommodating segmented structure.
4Reliability
If the seal contacts the shaft during shutdown to prevent leakage, then sealing effectiveness is improved, but wear increases due to contact while static
Solution Approach 1:
The packing rings are designed to be movable along the piston rod, allowing them to automatically engage with the rod surface during shutdown to prevent leakage. During operation, they can shift to reduce contact pressure and minimize wear. This dynamic capability allows the seal to contact the shaft only when necessary for sealing, avoiding premature wear from continuous contact.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A seal assembly for a reciprocating rod of a reciprocating compressor, a reciprocating compressor with the seal assembly, and a method of operating the reciprocating compressor with the seal assembly to prevent leakage of gas once the compressor has been shut down. The pressure difference between opposite sides of a static seal is kept low during normal operation to reduce wear of the static seal. When the compressor is shut down, a high pressure difference between opposite sides of the static seal assists with sealing.