Page 265 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Mechanical Separations 235

Table 4-7
General Applications of Liquid Particle Separators

COLLECTOR TYPES
Impinge- I
Operation Concentration Particle Sizes Gravity ment Cyclone Scrubbers Electrical
Pipeline entrained liquid light fine to coarse No Frequent Yes Occasional Few
Compressor discharge liquid light fine No Frequent Occasional Occasional Rare
Compressor oil haze very light very fine No Frequent Frequent Frequent Occasional
Flashing liquid light to mod. fine to medium No Frequent Frequent Occasional Rare
Boiling or bubbling light to heavy fine to coarse Occasional Frequent Frequent Occasional Rare
Spraying light to heavy fine to coarse No Frequent Frequent Rare Rare
Corrosive liquid particles light to heavy fine to coarse Occasional Frequent Occasional Frequent Rare
Liquid plus solid particles light to heavy medium Occasional Occasional Frequent Frequent I Occasional

100,000 '"
'�
I� Symbols and Legend
�� Ap= Area of Particle Projected on Plane Normal to
Direction of Flow or Motion, sq. fl.
"\ c =Overall Drag Coefficient, Dimensionless
10,000 ' "" " ... Op =Diameter of Particle, ft .
... ' Fd =Drag or Resistance lo Motion of Body in Fluid,
""" ��
ct <, ,, Poundals
i:-i
... ..... � NR,=Reynolds Number, Dimensionless
u, N ::, 1,000 " ,,
-� ' . � u =Relative Velocity Between Particle and Main Body
II I'' of Flu id , ft./sec.
- <, � p
u I� JJ, = Fluid Viscosity, (lb. mass) I ( ftXsecJ = Centipoises + 1488
c:
a,
:� 100 ,, =Fluid Density ,(lb.mass)/(cu. ft.)
::::: <, r� (Any Consistent System of Units may be Employed in
Place of the English Units Specified l
"'
0
u <, "' �
... 1, "I �
Cl
0
Q 10 -- Spheres
...... --- Disks
� ... - � -- Cylinders
:,.,..._ --
-ol:;. .. � ==:- -- .. - --
1.0 - _-:,. ' -
\ ..
\ �
0.1
0.0001 0.001 0.01 0.1 1.0 10 100 1,000 10,000 100,000 1,000,000
DpPU
Reynolds Number , NRe = T
Figure 4-6. Drag coefficients for spheres, disks, and cylinders in any fluid. By permission, Perry, J. H., Chemical Engineers Handbook, 3rd Ed.,
McGraw-H!ll Company, 1950.

sels, the wall effect can become significant (see Refer- Where D' P = diameter of particle, in. or mm
ence [231). a., = acceleration due to gravity, 32.2 ft/s or 9.8 m/s 2
2
Pp = density of particles, lb/ft 3 or kg/rn3
P1 = density of fluid, lb/ft3 01' kg/rn 3
For a single particle, DP can be taken as 2 (hydraulic µ = viscosity of fluid. cp
radius), and the Sauter mean diameter for hindered b , = constant given above
particles. n = constant given in text.