Time-Resolved γ-Densitometry Imaging within Fluidized Beds

Abstract

γ-Densitometry is a nonintrusive measuring technique applicable to mulitiphase flows. In most cases, the time-averaged spatial distribution of the phases is measured. A combination of high spatial and temporal resolution simultaneously would provide valuable information of flowing multiphase systems. In this work, γ-ray densitometry is reexamined, specifically the reduction of sampling times and the ability to visualize evolving structures within fluidized beds. A multiple fan beam configuration using static 137 Cs sources is evaluated by performing simulated reconstructions of the two-dimensional void fraction distribution within a 400 mm diameter fluidized bed. Results for both three and five source systems are presented, which indicate that spatial and temporal resolutions of 10 mm and 10 ms are achievable.