On trajectory and velocity measurements in fluidized beds using positron emission particle tracking (PEPT)

Abstract

Positron emission particle tracking (PEPT) is a non-invasive technique that can be used for following the trajectories of particles in fluidized beds, so increasing understanding of solids motion in fluidized bed processes. We describe how PEPT is applied, how its performance is optimized, and how trajectory information can be built up into instantaneous and time-averaged measures of particle movement. Choices and pitfalls in data processing are explained and illustrated by reference to the travelling fluidized bed (TFB) collaboration initiated by Professor John Grace.

Development of an imaging method for in vivo single-cell tracking under high-noise conditions: a proof of principle

“…Therefore, one of the applications of PEPT can be the acquisition of information on the environment and processes by observing how this tiny amount of radioactive substance (hereafter called 'particle') reacts to its surroundings and environmental conditions. If placed in a process with a complex flow field, such as stirring [6], mixing [7], fluidisation [8] and separation [3], and if the particle properties are representative of the processed matter, flow patterns can be revealed in detail by following the radioactive particle with adequate spatial and temporal resolution.…”

Numerical Modelling and Imaging of Industrial-Scale Particulate Systems: A Review of Contemporary Challenges and Solutions

“…Like ECT, PEPT has been applied to the study of a wide range of industry-relevant processes and unit operations, including pipe flow (Fairhurst et al, 2001), diverse types of mixers (Jones and Bridgwater, 1998;Marigo et al, 2013;Mihailova et al, 2015), stirred tank reactors (Fangary et al, 2000), fluidized (Leadbeater et al, 2023), spouted (Al-Shemmeri et al, 2021, and vibrated beds (Windows-Yule et al, 2014), cyclonse (Chan et al, 2009), drum roasters (Al-Shemmeri et al, 2023), mills (Conway-Baker et al, 2002), froth flotation devices (Cole et al, 2022), extruders (Diemer et al, 2011), and even household appliances such as washing machines, dishwashers and tumble dryers (Pérez-Mohedano et al, 2015;Jones et al, 2022).…”

Targetry for the in-beam activation of tracer particles for positron emission particle tracking

“…The tracer particle acts as a small, neutrally buoyant, flow-follower in a viscous fluid, suitable to study fluid or granular behaviour in packed beds, tumbling mills and/or other flow systems [3][4][5]. The PEPT technique is particularly useful in studying well-mixed systems where tracking a single particle over an extended duration provides essentially the same information as simultaneously observing the instantaneous motion of all the particles in the fluid -formally referred to as ergodic systems [6]. Analysis of the single-particle trajectory over long timescales (minutes to hours) can provide time-averaged maps of velocity fields, the shape of dense flow regions, identification of regions of low-velocity flow, observation of gravity-dominated flows, and etc.…”

“…Analysis of the single-particle trajectory over long timescales (minutes to hours) can provide time-averaged maps of velocity fields, the shape of dense flow regions, identification of regions of low-velocity flow, observation of gravity-dominated flows, and etc. [6].…”