An analysis of the process of active enhancement of falling film absorption

Abstract

 We study here the process whereby active enhancement intensifies absorption rates over vertical flat plates. Towards capturing the essential aspects of this process, we employ a model already developed, introducing new heat and mass transfer coefficients. It is shown that when the enhancement is done by a vibrating screen, it is possible to estimate the absorption rates employing simple parameters such as the plate peak velocity, vibrational frequency and amplitude. The predictions obtained are compared to recent experimental data. Although the prediction with this simple model is not exact, the essential features of the enhancement technique seem to be reflected quite well. Our calculations allow identification of the factor possibly limiting absorption. Estimates of the ultimate absorption rates possible with the limiting factor removed are offered, along with speculative thought as to whether this limiting factor can indeed be neutralized by mechanical agitation.