The critical suspended particle size is defined as the suspended parti
cle size with a minimum collector efficiency in a packed bed filter. I
dentification of the critical size particles is important when a granu
lar filtration process is designed for removal of a mixture of suspend
ed particles with different particle sizes. This note intends to deriv
e a simple expression from the filtration model of Rajagopalan and Tie
n [Rajagopalan, R. and Tien, C. (1976) Trajectory analysis of deep-bed
filtration with the sphere-in-a-cell porous media model. AIChE J. 2(3
), 523-533.] for the critical particle size and to investigate the eff
ects of temperature, suspended particle density, collector diameter an
d approach velocity on the critical particle size and the correspondin
g collector efficiency. (C) 1998 Elsevier Science Ltd. All rights rese
rved.