Fluidized bed pressure probes
Detailed information on local fluid bed behavior cannot be obtained using global instrumentation. However, dual static pressure probes (DSPP) which measure local axial differential pressures can be used to infer the presence of bubbles or slugs in a fluid bed. DSPP consist of two probe stems, one positioned vertically above the other, connected to a differential pressure transducer. Response of DSPP has been modeled and is fast enough to capture transient phenomena in a fluid bed provided a low dead volume transducer is used. DSPP with 0.5 inch, 0.75 inch and 1 inch stem spacings have been used to measure slugging properties of a 5.5 inch diameter air-fluidized bed filled with 0.125 inch nylon spheres. Over 500 20 second pressure traces were digitally recorded for two distributor types a variety of bed heights, air flowrates and probe positions. Slugging frequency was found from the traces using the autocorrelation function, Fourier transform and spectral density function, and was shown to decrease with bed height. Slug velocity was found using cross-correlation of signals from two DSPP, and was shown to increase with air throughput. In addition, analysis was performed to show that a distribution of bubble sizes in a fluid bed can be inferred from a distribution of chord lengths found using a probe, and pressure fields around bubble pairs were modeled. The research showed that DSPP can be used successfully to measure local phenomena in fluid beds. 27 refs., 88 figs., 4 tabs.
- Research Organization:
- West Virginia Univ., Morgantown, WV (USA). Dept. of Mechanical and Aerospace Engineering; West Virginia Univ., Morgantown, WV (USA). Dept. of Chemical Engineering
- Sponsoring Organization:
- DOE/FE
- DOE Contract Number:
- FC21-87MC24207
- OSTI ID:
- 6858745
- Report Number(s):
- DOE/MC/24207-2855; ON: DE90009666
- Country of Publication:
- United States
- Language:
- English
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COMBUSTORS
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DATA ACQUISITION
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FINITE ELEMENT METHOD
FLUID FLOW
FLUIDIZED BEDS
FLUIDIZED-BED COMBUSTORS
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PROBES
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