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Experimental Study on Time Features of Particle Motion in Rotating Drums
Author(s) -
Liu X. Y.,
Xu X.,
Zhang Y. Y.
Publication year - 2011
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201000483
Subject(s) - residence time (fluid dynamics) , drum , dimensionless quantity , rotational speed , coating , mechanics , rotation (mathematics) , particle (ecology) , work (physics) , residence time distribution , materials science , degree (music) , mathematics , composite material , engineering , mechanical engineering , physics , acoustics , flow (mathematics) , geometry , oceanography , geotechnical engineering , geology
Rotating drums are widely used in pharmaceutical industry to coat tablets. The motion of the tablet particle is one of the most important factors affecting coating uniformity. The purpose of the research is to experimentally investigate two important time variables for the coating process, residence time and turnover time, and their dependence on operating parameters (rotation speed and filling degree of the drum). The average residence time was found to decrease with increasing rotation speed and filling degree. The average turnover time was observed to increase approximately linearly with the inverse of the drum speed, but was found to be independent of the filling degree. A dimensionless time variable, the fractional residence time, i.e., the residence time divided by the turnover time, was introduced. Analysis showed that the fractional residence time could be a good indicator of coating uniformity. Results of the present work provide useful information for theoretical modeling which may ultimately serve as a tool for coating optimization.