Closed Impeller Compressor Train for Ethylene Plants
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Solution Overview
Problem
Open impeller compressors in ethylene plants experience efficiency deterioration due to higher gas leakage, leading to increased dimensions and costs when attempting to compensate with more impellers and larger diameters.
Innovation Solution
Implementing a closed impeller design with a shroud at each compression stage, featuring an outer diameter of 1,400 to 1,800 mm and a maximum peripheral speed of 350 to 400 m/s, to reduce gas leakage and increase capacity without enlarging the compressor size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an open impeller is used, then the compressor structure is simpler, but gas leakage increases and efficiency deteriorates
Solution Approach 1:
The patent changes the impeller type from open to closed, and optimizes the blade outer diameter to 1,400 to 1,800 mm with peripheral speed of 350 to 400 m/s. This parameter change reduces gas leakage while maintaining reasonable structural complexity, resolving the contradiction between simplicity and efficiency.
2Productivity
If the number of impellers and impeller diameter are increased to compensate for efficiency loss, then compressor capacity increases, but compressor dimension and cost increase
Solution Approach 1:
The patent uses optimized parameter settings (blade outer diameter 1,400 to 1,800 mm, peripheral speed 350 to 400 m/s) to achieve high capacity without increasing compressor dimensions. The closed impeller design with specific dimensional parameters allows maintaining compact size while improving productivity.
3Productivity
If the blade peripheral speed is increased to improve compression performance, then compression efficiency increases, but the risk of fouling and wear on blades increases
Solution Approach 1:
The patent sets the blade peripheral speed to 350 to 400 m/s, which is an optimized range that balances compression efficiency with blade durability. This parameter optimization allows achieving high productivity while minimizing the risk of fouling and wear, resolving the contradiction between performance and reliability.
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
This configuration results in a smaller, more efficient charge gas compressor train with increased capacity, reducing construction and maintenance costs while minimizing the risk of fouling and wear on blades.
Implementation Method 1
a steam turbine; and a compression unit that is driven by the steam turbine
Implementation Method 2
a compression unit that is driven by the steam turbine to compress a charge gas
Data Source
AI summary
A charge gas compressor train for an ethylene plant includes: a steam turbine; and a compression unit that is configured to be driven by the steam turbine to compress a charge gas. The compression unit includes a closed impeller at each impeller of a plurality of compression stages. An outer diameter of blades of the closed impeller at least at an initial stage of the plurality of compression stages is 1,400 to 1,800 mm. A maximum operating peripheral speed of the blades of the closed impeller at the initial stage at an outermost diameter position is 350 to 400 m/s. An output of the charge gas compressor train is 100 to 140 MW.