Frequency Response of the Back-flow Cell Model of Mass-Transfer Processes: Packed-Column Characteristics for Tracer-Gas Absorption

Frequency-response techniques are developed for the backflow cell model as applied to countercurrent two-phase flow processes with exchange of a single solute. Experimental outlet-gas response curves have been obtained for step injection of tracer gas into the air inlet of a six-inch packed bubble column with different countercurrent flow rates of water. Numerical Fourier transformation of these curves yields frequency-response characteristics that are compared with those of the backflow cell model. On this basis, the backflow cell model adequately simulates the dynamics of the system.