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Minimum pickup velocity: The transition between nano‐scale and micro‐scale
Author(s) -
Anantharaman Aditya,
van Ommen J. Ruud,
Chew Jia Wei
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15527
Subject(s) - pickup , particle (ecology) , nano , scale (ratio) , mechanics , rest (music) , nanotechnology , physics , materials science , engineering , chemical engineering , computer science , geology , quantum mechanics , artificial intelligence , image (mathematics) , oceanography , acoustics
The transport of nano‐scale particles has become increasingly important, but the knowledge base available is limited. This study aims to bridge the knowledge gap between the nano‐ and micro‐scales for pneumatic conveying. A key parameter is the minimum pickup velocity (U pu ), which is the minimum fluid velocity required to initiate motion in a particle originally at rest. The U pu values of nine alumina particles with particle diameters (d p ) ranging from 5 to 110,000 nm were determined using the weight loss method, then compared against the established pickup Zones (analogous to the Geldart Groups). Results indicated that: (1) U pu varied non‐monotonically with increasing d p , thus revealing the missing link between the nano‐ and micro‐scales; (2) the intermediate particle diameters surprisingly did not agree with any pickup Zone; (3) Zone III (analogous to Geldart Group C) is inadequate for all the nano‐scale particles, so new boundaries and a new Zone are proposed. © 2016 American Institute of Chemical Engineers AIChE J , 63: 1512–1519, 2017