Improved multiple‐particle tracking for studying flows in multiphase systems

Abstract

in Wiley InterScience (www.interscience.wiley.com).Positron Emission Particle Tracking is a powerful and noninvasive technique and has been successfully used in a wide range of fundamental research and industrial applications. However, it is only capable of following a single tracer. This article presents a Multiple-Positron Emission Particle Tracking technique for tracking two freely moving particles in opaque systems and its application. The developed technique has been validated through tracking two stationary particles and two moving particles, respectively. The results showed that it is a reliable technique and can be potentially used to acquire more comparative information, such as the interactions and relative motions of particles with different sizes, densities, and material textures in multiphase systems. Tracking two polyethylene particles, labeled using 18 F, in a cylindrical fluidized bed has been given as an example. The information obtained provides significant insights into phenomena in flow and mixing processes.

Quantifying lateral solids mixing in a fluidized bed by modeling the thermal tracing method

“…By tracking a single particle continuously, the characteristics of particle motion can be effectively revealed. [13][14][15][16] In addition, solid dispersion coefficient can be calculated based on the trajectory. 13,14 More commonly, the dispersion coefficient is determined by measuring the dispersion of a batch of tracers and modeling using a Fickian-type diffusion equation.…”

PEPT visualisation of particle motion in a tapered fluidised bed coater

“…However, reasonable tracking can still be obtained for tracer speeds up to 10 m/s (Barigou, 2004). Recently, multiple-particle tracking was proposed as a further improvement of positron particle tracking (Yang et al, 2006(Yang et al, , 2007.…”

Modification of ilmenite surface chemistry for enhancing surfactants adsorption and bubble attachment

“…PEPT measurements were performed using a Forte positron camera manufactured by ADAC Laboratories, California [22][23][24]. The camera consists of two rectangular gamma camera heads, each of active area 500 × 400 mm 2 , separated by up to 750 mm.…”