Pressure Drop in Cyclones Reference: Reference: Chapter 4, 4, Equipment Sizing, 'Fortran 'Fortran Programs for Chemical Proc ess Design, Analysis & Simulation' b y 'A. Kayode Cok er'; Jan. 1995 1995
Dc
De
Rectangular Inlet
S a
h
b H
B
where: a= b= B= Dc = De = h= H= S=
inlet height, ft inlet width, ft cyclone dust-outlet diameter, ft cyclone diameter, ft cyclone gas-outlet diameter, ft cylindrical height of cyclone, ft total height, ft gas outlet length, ft
Equation for Pressure Drop
D P 0.003 r f vi N H 2
where: DP = rf =
pressure drop, inches H2O inlet gas density, lb/ft
vi =
inlet velocity, ft/s
NH =
number of inlet velocity heads, dimensionless
ab (Note 1) D e
N H K K= K=
2
16 for no inlet vane 7.5 with a neutral inlet vane
Inputs a= b= De = rf =
4.5 ft 1.896 ft 3.792 ft 0.075 lb/ft
Q= K=
516.7 ft /s 16
Calculations vi = NH = DP =
3
60.6 ft/s
(total gas flow rate)
(Q/ab) (Note1)
9.5 7.834 in. H2O 0.020 bar
Notes 2
1. For circular inlet to the cyclone use cross-sectional area as ' d /4' instead of 'ab' for rectangular inlet, where 'd' is inside diameter of inlet nozzle. 2. Correlations for the pressure drop have been empirical and are acceptable up to DP = 10 in. H20. The pressure drop (DP) or the frictional loss is expressed in terms of the velocity head based on the cyclone inlet area. The frictional loss through cyclones is from 1 to 20 inlet velocity heads and depends on the geometric ratios. Prepared by: Ankur Srivastava Chemical Engineer Email:
[email protected]
