Investigation on Flow Patterns and Transitions in a Multiple-Spouted Bed

Abstract

Experimental studies on flow patterns and transitions were carried out in a visible multiple-spouted bed. The bed combines three spouted bed cells, each with a cross-section of 100 × 30 mm, and each cell has an independent spout nozzle of 10 mm in width. Polypropylene beads with a density of 900 kg/m3 and mean diameter of 2.8 mm were used as bed materials. Six distinct flow patterns, i.e., fixed bed (FB), internal jet (IJ), internal jet with bubble (IJB), single spouting (SS), multi-spouting (MS), and internal jet with slugging (IJS), were determined on the basis of criteria as well as schematic diagrams and typical flow pattern images obtained from a high-resolution digital charge coupled device (CCD) camera. Typical flow regime maps at three static bed heights were plotted to describe the transitions of flow patterns with central and auxiliary spouting gases. Besides, some important flow characteristics associated with flow patterns and transitions, i.e., minimum spouted velocity and pressure drop, were...