The bubbling behavior of cohesive particles in the 2D fluidized beds

The present work focuses on a fully statistical analysis of bubbling behavior in the two-dimensional (2D) fluidized beds with cohesive particles. Various significant bubble properties such as bubble size, rising velocity, aspect ratio, bed expansion and bubble hold-up, etc., were investigated. An equation for bubble diameter is developed, db= 0.21(ug−umb)0.49(h+4A0)0.48/g0.2, and the observed bubbles are generally smaller than the ones generated in the beds with A or B type powders. Both the average bubble size and rising velocity initially increase with the elevation above the distributor and keep constant beyond certain heights. The bubbles exhibit oblong with the most density aspect ratio (β) equal to 0.7. In addition, the bubble rising velocity coefficient ranges from 0.8 to 1.5. Two core-annular flows form in the large diameter, shallow fluidized bed used in this experiment.

The bubbling behavior of the 2D fluidized beds with cohesive particles has been studied experimentally by using the digital image analysis technique. Various significant bubble properties such as bubble size, rising velocity, aspect ratio, bed expansion and bubble hold-up were investigated. The observed bubbles are generally smaller than the ones generated in the beds with A or B type powders.Figure optionsDownload as PowerPoint slideHighlights
► The bubbling behavior of cohesive particles is fully analyzed for the first time.
► The bubble diameter can be described by db= 0.21(ug−umb)0.49(h+4A0)0.48/g0.2.
► The bubbles are smaller than the ones generated in the beds with A or B type powders.
► The bubble rising velocity coefficient ranges from 0.8 to 1.5.