Downer reactor flow measurements using CREC-GS-Optiprobes

The present study describes the potential intrusive effects of CREC-GS-Optiprobes on the flow pattern in gas–solid downflow units. Granular flows and their interactions with the CREC-GS-Optiprobes are calculated using a CPFD (Computational Particle Fluid Dynamic) numerical scheme in three dimensions, using particle clusters. Once particles dispersed in the column, the numerical simulations revealed that these particles formed a relatively homogeneous suspension with cluster formation and solids accelerating until reaching a fully-developed regime. CPFD simulations showed that two axially aligned CREC-GS-Optiprobes, when placed in the fully developed flow regime, introduce minimum perturbations in the gas–solid suspension. Therefore this CREC-GS-Optiprobe creates a highly illuminated focal region where hydrodynamic parameters can be measured without significant flow disturbance. Thus, this study supports the application of fiber optic probes; such as in the case of the CREC-GS-Optiprobes, which can provide undisturbed axial particle cluster velocity, axial cluster slip velocities, cluster size and solid fraction measurements at strategically selected locations in the gas–solid downer unit.

The CREC-GS-Optiprobe consists of various components: a) the GRIN lens, b) the emitter optical fiber, and c) the receiver optical fiber. The laser beam is focused at the emitter fiber end and helps to create with the GRIN lens a focal region in front of the CREC-GS-Optiprobe. Solid particles crossing the focal region are detected with minimum flow disturbance.Figure optionsDownload as PowerPoint slideHighlights
► CREC-GS-Optiprobes create a focal region where hydrodynamic parameters are measured.
► CREC-GS-Optiprobes can be used for cluster velocity and solid fraction measurements.
► Granular flow interactions with CREC-GS-Optiprobes are calculated using CPFD.
► We show minimum intrusion of CREC-GS-Optiprobes on gas–solid downer unit flow.