LONGITUDINAL DISPERSION IN SOLVENT-EXTRACTION COLUMNS: PECLET NUMBERS FOR ORDERED AND RANDOM PACKINGS
Dispersion phenomena in packed beds in both axial and radial directions were studied to provide basic data for extraction-tower design. Nine different beds were used, involving regular and random arrangements of spheres, and random arrangements of Raschig rings and Intalox saddles. For one-phase flow a wide range of Reynolds numbers was used (5 to 2000), covering regions of laminar, transition, and turbulent flow. For the axial Peclet number, different constant values were found in the turbulent range and in the laminar range. The existence of a fairly sharp transition region was observed. Radial-dispersion results showed similar behavior. The axial Peclet number was found to vary inversely with bed porosity, while the radial Peclet number was almost proportional to porosity. For two-phase fiow, measurements were made up to the flooding point, which occurred at Reynolds numbers near 100. The axial Peclet number for both continuous and discontinuous phases is a function of the Reynolds numbers for the two individual phases. For each phase, the laminar value of the axial Peclet number obtained for one-phase flow is an upper limit. Values as low one- fifth of this limiting value were found at relatively large flow rates of the second phase. The radial Peclet number was measured only for the continuous phase of two-phase systems; it was found to decrease in the same direction, but by a smaller percentage. (auth)
- Research Organization:
- California Univ., Berkeley, CA (US). Radiation Lab.
- DOE Contract Number:
- W-7405-ENG-48
- NSA Number:
- NSA-12-004759
- OSTI ID:
- 4336744
- Report Number(s):
- UCRL-8029
- Country of Publication:
- United States
- Language:
- English
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