Mass transfer from granular beds

Experimental data on the mass transfer of four vapors from a packed bed of granular solids to a flowing air stream were obtained in the range of modified Reynolds numbers ranging from 300 to 2200. Three different sizes of porous right circular cylinders were used for packing. A turbulence effect, requiring a variable Schmidt number exponent for correlation of the data is postulated, and evidence for a wall effect, applicable to small beds, is presented. The limited data presented herein are combined with data of Hougen et al (7)(27)(31) to give the following equation: * [See PDF for equation] This empirical equation fits the data for a modified Reynolds number range of 300 to 2200 and may apply at higher Reynolds numbers. The data of Wilke and Hougen (31) indicate that another equation applies at lower Reynolds numbers. * For list of symbols and their meaning see page 38.