Effect of bed characteristics on local liquid spreading in a trickle bed

Abstract

Trickle bed reactors are important to several chemical process applications. While the available computational fluid dynamics models can predict overall liquid volume fraction, the prediction of spatial liquid distribution continues to be a challenging task. In the present work, Eulerian multifluid simulations were performed to investigate the effects of particle size, gas and liquid flow rates, and bed structure on local liquid spreading, and the predictions were validated using measured liquid spreading. It was found that the capillary pressure force caused liquid to spread in the lateral direction and that the interphase interaction forces pushed it in the downward direction and the relative magnitudes of these forces governed the local liquid distribution. While the use of existing capillary pressure force model led to satisfactory prediction of the observed trends of dynamic and steady state local liquid spreading, the modified capillary pressure force led to quantitatively correct predictions of local liquid spreading. © 2016 American Institute of Chemical Engineers AIChE J, 63: 347–357, 2017