Page 261 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Mechanical Separations 231

Figure 4-5. Efficiency curves for various types of dust collection equipment as of 1969. Only marginal improvements have been made since
then. By permission, Sargent, G.D., Chemical Engineering, Jan. 27, 1969, p. 130.

and hence, particles influence adjacent particles. This is If, K < 3.3, then Stokes' law applies. If 3.3 � K � 43.6, the
often termed hindered settling [23,46]. Depending upon intermediate law applies, and if K > 43.6, Newton's law
the particles concentration, the hindered terminal set- applies. If K > 2,360, the equations should not be used.
tling velocity will generally be somewhat lower than for
the terminal settling velocity of a single desired particle in Values of a and b 1
the same medium.
From Reference [ 46]: =========-=====-:=--=== -- --
K is a dimensionless number that establishes the Law Range b1 a
regime of settling class, reference to the settling laws: Stokes' K< 3.3 24.0 1.0
Intermediate 3.3 � K� 43.6 18.5 0.6
Newton's K> 43.6 0.44 0
=-.cc=======��- - - �- - ---=- --
113
[
_ , p f (p p - p f ) ]
K - 34.8 DP (4-10)
µ 2 (text continued 011 page 234)