Developing X-Ray Particle Tracking Velocimetry for Applications in Fluidized Beds

Abstract

Fluidized beds utilize a gas stream to fluidize solid particles and are used in the process industries because they provide a low pressure drop, uniform temperature distribution, and high heat transfer rates. Knowledge of fluidized bed hydrodynamics is necessary in the design and scale up of such devices. However, fluidized bed hydrodynamics are difficult to visualize and quantify because the systems are opaque and intrusive probes do not provide satisfactory measurements. This paper describes the development of X-ray particle tracking velocimetry (XPTV) to study fluidized bed hydrodynamics. XPTV utilizes X-rays to track specially designed tracer particles in a fluidized bed to noninvasively determine particle velocities. Stereoscopic X-ray imaging is used to locate the 3D position of the tracer particle as a function of time within a fluidized bed, from which particle velocity can be determined. An example of particle tracking will be shown and the automation of this process will be described.