Effect of modified inlet flow strategy on the segregation phenomenon in pulsed fluidized bed of ultrafine particles: A collapse bed study

Unlike conventional fluidization of micron-sized particles, the hydrodynamics of ultrafine nanopowders is controlled by their agglomerates, which show strong segregation pattern along the bed height. This aspect was carefully investigated in this study by carrying out collapse experiments in a low-frequency pulsed fluidized bed. Unlike previous studies, the inlet flow was modified with the help of four-way valve configuration to eliminate the inlet flow spike. The region-wise collapse dynamics was monitored by recording pressure transients along the height of the fluidized bed while double drainage deaeration strategy, termed modified dual drainage (MDD), was employed. The size of agglomerates in the different bed regions were evaluated and compared with the conventional single drainage (SD) and dual drainage (DD) deaeration configurations using two-way and threeway solenoid valves. The elimination of the flow spike with MDD helped to suppress the size-based segregation of agglomerates, thereby resulting in faster and smoother bed collapse.

Automated summary

This study investigated the hydrodynamics of ultrafine nanopowders by modifying the inlet flow and using an improved dual drainage strategy. The results showed that these methods helped to suppress size-based segregation of agglomerates, leading to faster and smoother bed collapse.