Analysis of gamma-ray imaging data to describe hydrodynamic properties of gas-polyethylene fluidized beds

Citation
T. Zarabi et A. Kantzas, Analysis of gamma-ray imaging data to describe hydrodynamic properties of gas-polyethylene fluidized beds, CAN J CH EN, 78(5), 2000, pp. 849-857
Citations number
12
Categorie Soggetti
Chemical Engineering
Journal title
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
ISSN journal
00084034 → ACNP
Volume
78
Issue
5
Year of publication
2000
Pages
849 - 857
Database
ISI
SICI code
0008-4034(200010)78:5<849:AOGIDT>2.0.ZU;2-V
Abstract
A scintillation gamma camera was used for measuring the instantaneous veloc ity profile and average velocity as well as the trajectories of a radioacti ve particle in small laboratory scale air-polyethylene-fluidized beds. A la rge number of frames, with frequencies between 1 and 50 Hz, were analyzed t o investigate the effects of bed height, gas velocity and particle morpholo gy. Subsequently: (1) horizontal and axial variations of the particle veloc ity were found; (2) three different flow zones along the axis (i.e., entran ce zone, circulation zone and free board) were quantified; and (3) a charac teristic time and a new definition of circulation (cycle) period were intro duced. It was also found that the particle sometimes oscillates in the free board or gets trapped in the entrance zone.