Page 318 - Air Pollution Control Engineering

05_chap_wang.qxd 05/05/2004 3:51 pm Page 297
Wet and Dry Scrubbing 297

G Gas stream flow rate based on tower cross-sectional area at flooding
area, f
2
point (lb/ft -s)
G Gas flow rate (lb-mol/h)
mol
HAP Hazardous air pollutant
HAP HAP emission stream concentration (ppmv)
e
HAP Moles of HAP in inlet stream (mol/min)
e,m
HAP HAP outlet concentration (ppmv)
o
HAP Moles of HAP in outlet stream (mol/min)
o,m
H Height of gas transfer unit (ft)
G
H Height of liquid transfer unit (ft)
L
H Height of an overall gas transfer unit based on overall gas film coef-
og
ficients (ft)
hp Horsepower
HRS System operating hours (h/yr)
Ht Column (packed tower) height (ft)
column
Ht Total column height (ft)
total
Ia Known cost of existing system
Ib Cost of system being sized
IAC Indirect annual cost
L Solvent flow rate (lb/h)
2
L'' Liquid flow rate per cross-sectional area of column (lb/h-ft )
L Solvent flow rate (gal/min)
gal
L Liquid (absorbent) flow rate (lb-mol/h)
mol
L Saturated lb water/lb dry air (from psychrometric chart)
w,s
L Inlet lb water/lb dry air (from psychrometric chart)
w,a
m Empirical parameter or slope of the equilibrium curve
M Molecular weight of specific pollutant gas (lb/lb-mol)
M Moisture content (%)
e
MW Molecular weight of the scrubbing liquor (lb/lb-mol)
MW Molecular weight of the emission stream (lb/lb-mol)
e
MW Molecular weight of HAP (lb/lb-mol)
HAP
MW Molecular weight of solvent (lb/lb-mol)
solvent
n Sizing exponent
N Number of gas transfer units (based on overall gas film coefficients)
og
(dimensionless)
ORD Flooding correlation ordinate
P System pressure drop (in. H O or atm)
2
2
P Pressure drop (lb/ft -ft)
a
PM Particulate matter
P System pressure drop (in. H O)
total 2
P Venturi scrubber pressure drop (in. H O)
v 2
P Pressure of emission stream (mm Hg)
e
PEC Purchased equipment cost ($)
Q Emission stream flow rate (scfm)
e
Q Dilution air required (scfm)
d