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End effects in flow-analysis and process systems
1Institute of General and Analytical Chemistry, Technical University of Budapest, Gellért tér 4, H-1502 Budapest XI, Hungary.
Talanta
|December 1, 1987
Summary
Investigating end effects in flow systems using the axially-dispersed plug-flow model, this study quantizes how fore- and after-sections influence system responses. Results aid in designing systems where upstream or downstream phenomena do not impact overall performance.
Area of Science:
- Chemical Engineering
- Process Systems Engineering
- Fluid Dynamics
Background:
- End effects in flow analysis and process systems can significantly alter system responses.
- The axially-dispersed plug-flow model is a common framework for analyzing such systems.
- Understanding these effects is crucial for accurate system design and performance prediction.
Purpose of the Study:
- To theoretically investigate the impact of end effects in flow analysis and process systems.
- To analyze the influence of finite and infinite length fore- or after-sections on system responses.
- To provide guidance for determining optimal lengths of these sections in practical applications.
Main Methods:
- Utilized the axially-dispersed plug-flow model for theoretical investigation.
- Employed a three-section system model including reactor, fore/after-section, and an additional section with back-mix flow (Peclet number = 0.01).
- Analyzed system responses to a delta-function input signal using statistical moments and response curves.
Main Results:
- Quantified the differences in system responses for finite versus infinite fore- or after-section lengths.
- Demonstrated the impact of back-mix flow in the additional section (Peclet number = 0.01).
- Established a method to evaluate the necessary lengths of fore- and after-sections.
Conclusions:
- The length of fore- and after-sections critically influences system response due to end effects.
- The findings enable engineers to design process systems minimizing unwanted upstream or downstream influences.
- Accurate evaluation of section lengths ensures reliable system performance and data interpretation.
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