Page 317 - Air Pollution Control Engineering

05_chap_wang.qxd 05/05/2004 3:51 pm Page 296
296 Lawrence K. Wang et al.

pollution control perspective (for treatment of the contaminated air emission stream),
it is a scrubbing (absorption) process, whereas from a water pollution control perspec-
tive (for treatment of the contaminated groundwater), it is a gas stripping process.
The process system introduced here employs two separate but almost identical pro-
cess units connected to each other. A gas-stripping process unit removes ammonia
from a contaminated wastewater and a scrubbing (absorption) process unit recovers
the stripped ammonia gas from the emitted gas stream for reuse.

NOMENCLATURE
a Empirical packing constant (dimensionless)
2
A Bed area (ft )
bed
acfh Actual cubic feet/hour
acfm Actual cubic feet/minute
2
A Column (tower) cross-sectional area (ft )
column
AF Absorption factor
3
am /h Actual cubic meters/hour
ABS Flooding correlation absicca
AEC Annual electricity cost ($)
Aex Auxiliary equipment cost ($)
ASC Annual cost of solvent ($/yr)
ASR Annual solvent required (gal/yr)
AVV Absolute void volume (dimensionless)
b Empirical packing constant (dimensionless)
c Empirical packing constant (dimensionless)
Ca Size of existing system
Cb Size of system being considered
CE Collection efficiency (%)
d Empirical packing constant (dimensionless)
3
D Density (lb/ft )
DAC Direct annual cost ($)
D Column (tower) diameter (ft)
column
3
D Density of polluted airstream (lb/ft )
e
3
D Density of gas stream (lb/ft )
G
3
D Density of HAP (lb/ft )
HAP
3
D Density of liquid (lb/ft )
L
D Particle diameter (µm)
p
3
D Density of water vapor (lb/ft )
w
e Empirical packing constant (dimensionless)
EC Equipment cost ($)
f Fraction of flooding
F Fan power requirement (kWh/yr)
p
g Empirical packing constant (dimensionless)
G Gas flow rate (lb/h)
2
g Gravitational constant (32.2 ft/s )
c
2
G Gas stream flow rate based on tower cross-sectional area (lb/ft -s)
area