Computer Automated Radioactive Particle Tracking

Direct measurement of particle velocity and velocity fluctuations in fluidized beds or riser reactors is necessary for validating multiphase models. Dudukovic [14] and Roy and Dudukovic [28] have used computer-automated radioactive particle tracking (CARPT) to foUow particles in a riser reactor. From their measurements, it was possible to calculate axial and radial solids diffusion as well as the granular temperature from a multiphase KTGF model. Figure 15.10 shows one such measurement... 

J. Chen, R. Novica, M.H. Al-Dahhan, M.P. Dudukovic, Study of particle motion in packed/ebullated beds by computed tomography (CT) and computer automated radioactive particle tracking (CARPT), AIChE J. 47 (5) (2000) 994-1004. 

Computer-automated radioactive particle tracking (CARPT) (Cassanello et al. 

To properly test the flow pattern in the cold flow model of the riser (Fig. 1.6 Roy, 2000), a conventional tracer study was first conducted that showed the Hquid was essentiaHy in plug-flow with a RTD equivalent to greater than about 20 tanks-in-series for the given operating conditions. The Computer Automated Radioactive Particle Tracking (CARPT) faciHty in CREL was used to determine the soHds flow pattern in the riser, and the... 

Rammohan AR, Kemoim A, Al-Dahhan MH, Dudukovic MP A Lagrangian description of flows in stirred tanks via computer-automated radioactive particle tracking (CARPT), Chem Eng Sci 56 2629-2639, 2001a. http //dx.doi.org/10.1016/S0009-2509(00)00537-6. 

Chen JAK, Al-Dahhan Muthanna H, Dudukovic Milorad P, Lee DJ, Fan LS Comparative hydrodynamics study in a bubble column using computer-automated radioactive particle tracking (CARPT)/computed tomography (CT) and particle image velocimetry (PIV), Chem Eng Sd 54 2199-2207, 1999. 

Our understanding of the hydrodynamics of multiphase flows has progressed substantially in the recent three decades, thanks to the development of advanced experimental techniques, particularly laser Doppler anemometry (LDA), particle image velocimetry (PIV), computer-automated radioactive particle tracking (CARPT), and optical bubble probes. In addition, computational fluid dynamics (CFD) simulations allow for inner views in two-phase process equipment. 

The radioactive-tracer technique was perfected for. fluidized-bed application through the development of a computer-aided particle-tracking facility (CAPTF) (Lin, Chen, and Chao, 1985 Moslemian, 1987 Sun, 1989). Considerable effort was expended to develop the efficient photoncounting instrumentation and automated data reduction and processing schemes. In Section 9.2, the principle of radiation detection and a theoretical model of the CAPTF is presented. The instrumentation of the CAPTF and the data reduction schemes are described in Section 9.3. Sample results obtained by the CAPTF are presented in Sections 9.4 and 9.5, and a conclusion is presented in Section 9.6. 

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