Modeling and measurement of bubble size in a rotating fluidized bed

Abstract

AbstractModeling and measurement of bubble size in a rotating fluidized bed (RFB) is described. A novel model of bubble growth has been proposed based on a bubble coalescence model by Darton et al. We modified the model according to the following concepts: (i) local centrifugal acceleration and excess gas velocity are considered as the parameters in the radial direction and (ii) bubble volume flow rate locally changes depending on the radial distance. Bubbling behavior in a two‐dimensional RFB was experimentally observed by means of a high‐speed video camera. Bubble sizes were measured using an image analysis technique. The estimated bubble sizes by our proposed model showed good agreement with the experimental results, while the estimated values by the model for conventional fluidized bed underestimated. The bubble growth mechanism in an RFB was also discussed and then concluded that the initial bubble size decreases, and the rate of bubble growth increases with an increase in the centrifugal acceleration. © 2007 American Institute of Chemical Engineers AIChE J, 2007