Impact of flow-corrective insert on flow patterns in two-dimensional moving bed

• Published in: Chemical engineering and processing 2013-11, Vol.73, p.7-15
• Main Authors: Hsiau, Shu-San, Smid, Jiri, Chyou, Yau-Pin, Liu, Ti-Chen, Huang, Ta-Ching, Hsu, Chia-Jen
• Format: Article
• Language: English
• Subjects: Flow-corrective insert; Granular moving bed; Internal flow pattern; Two-dimensional apparatus
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2013.07.001

•We show how to demonstrate a mass flow of granular media in a 2D apparatus.•A flow corrective insert could change powder from funnel flow to mass flow.•Velocity vectors of tracer particles are evaluated in four horizontal levels.•Vertical shift of insert may make a function of insert inefficient. This paper presents the study of the flow patterns inside a granular moving bed in a quasi-two-dimensional (2D) model of a granular moving bed filter (GMBF) vessel with vertical walls and a mass flow hopper. Fine quartz sand was chosen as the granular filter media in experiments. The related flow properties were measured by a Jenike Shear Tester. According to the flow properties of fine silica sand and Johanson's theory, a 2D moving-bed apparatus was built, with transparent walls and the flow-corrective insert to diminish the quasi-stagnant zones along the side walls. The flow patterns and velocity profiles of silica sand in the system with flow-corrective insert were studied experimentally, and the effect of the location of the flow-corrective insert on the internal flow patterns was investigated. The optimal placement of flow-corrective insert according to Johansson's theory was demonstrated to efficiently diminish the quasi-stagnant zones near the side walls. Little vertical shift of the flow-corrective insert from optimal position changed the stable and uniform mass flow pattern of moving bed into the funnel flow.