| Author(s) | Waheed A. Al-Masry and Emad M. Ali |
| Affiliation | Department of Chemical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia |
| Title | Effect of Sampling Frequency and Surfactants on Regime Transitions in Bubble Columns Using Differential Pressure Signals |
| Source | Journal of King Saud University. Engineering Sciences. Volume 19, No 2. (2007/1427) |
| Abstract | In this paper, the influence of data sampling frequency and the inclusion of surface active agent on the flow pattern in bubble columns is investigated. The study is based on applying statistical, spectral and fractal metrics on recorder differential pressure measurements of air-water system. It is found that a highly sampled pressure signals can provide useful information using spectral and statistical tools, whereas a slowly sampled signal can only deliver meaningful details when spectral analysis is employed. Moreover, the addition of 5% polyethylene, which acts as coalescence inhibitor, to the air-water system showed a similar statistical and spectral behavior to that of sole air-water system. However, the averaged-frequency of the power spectra and the Hurst exponent managed to unfold the characteristics of flow regimes in both media and to disclose the discrepancy between coalescing (air-water) and the non-coalescing (5% polyethylene in air-water) solutions. Keywords: Differential pressure, Bubble column, Hydrodynamics, Regime transition, Hurst analysis |
