Tomographic Techniques for Characterising Particulate Processes

Abstract

A review of existing and developing process tomographic different image reconstruction methods. Examples of existing, instrumentation suitable for characterising dry and wet partic-developing and proven applications are cited. Future needs and ulate systems is presented. Factors governing the selection of ways in which these needs can be met are suggested, including sensing techniques appropriate for static and dynamic imaging the use of multi-modality methods in which different types of of a wide range of single and multiphase particulate processes sensing methods are embodied in a single tomographic instruare discussed. The paper presents a systematic comparison of ment. 0 VCH Verlagsgesellschaft mbH, D-69469 Weinheim, 1993 0934-0866/93/0511-0252 $5.00 + .25/0 E. I! Lopes: Electromagnetic geophysical tomography. IEE Proc.-F H? Daily, A . Ramirez D. LaBrecque, I Nitao: Electrical resistivity tomography of vadose water movement. J. Water Resources Res. 28 (1992) 1429-1442. A. M. Binley, I? J. Dickin, S. A. Henry-Poulter; M. 2. Abdullah, I? J Gregory: Obervation of tracer migration in soils using resistive electrical impedance tomography. Proc. European Concerted Ac-Suppl. A I1 (1989) 275-281. 1883-1897.pp. 443-452.

Liquid Distribution in Trickle-Bed Reactor

“…Tomographic measuring techniques are more and more widely used in the investigation of the hydrodynamics of multiphase reactors, as shown in a number of recent review papers (Williams and Xie, 1993;Beck et al, 1997;Chaouki et al, 1997;Reinecke et al, 1998). Each of the different possible tomographic techniques has its advantages and drawbacks: the X-ray tomography used by Toye et al (1996Toye et al ( , 1997 is well suited for very small velocities, since the gasliquid repartition has to be constant during a measurement, which is quite slow.…”

Investigation of the effect of impeller rotation rate, powder flow rate, and cohesion on powder flow behavior in a continuous blender using PEPT

“…Several tracking techniques have been used in order to understand granular motion: MRI (Metcalfe et al, 1998), X-ray tomography (Powell and Nurick, 1996), impedance tomography (Williams and Xie, 1993), and positron emission particle tomography (PEPT). Specifically, as discussed below, PEPT has been used in a number of systems with interesting results.…”

X-ray computer tomography — potential and limitation for the measurement of local solids distribution in circulating fluidized beds

“…In literature a lot of physical sensing methods, available for tomographic measurements, and as well a great number of possible reconstruction techniques can be found [6]. The physical measuring system to obtain the distributions of local solids concentration presented in this paper consists of an x-ray source and an x-ray linear detector to measure the attenuation along a multitude of ray paths through the sample.…”

“…For industrial applications ART is rather used than e.g. Fourier inversion or convolutional backprojection, because it shows better results with limited data and it is very easy to incorporate prior knowledge like restrictions in the reconstruction area [6].…”