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92 Lawrence K. Wang et al.

from the literature (32) to be 336.6. The March 2002 CE equipment cost index can also
be obtained from a different issue of the same source (27). In turn, the March 2002
equipment costs can be calculated using the known values of Cost , Index , and
9-1986 3-2002
Index :
9-1986
Cost = Cost (Index )/Index
3-2002 9-1986 3-2002 9-1986,
Readers are referred to ref. 37 for more detailed information on cost estimation.

NOMENCLATURE
2
A Net cloth area (ft )
nc
2
A Gross cloth area (ft )
tc
c Flow constants
C Initial bag cost ($)
B
C Bag replacement cost ($)
RB
Cost Equipment cost ($)
CRF Capital recovery factor
B
D Particle mean diameter (µm)
P
DAC Direct annual costs ($)
ε Porosity or fraction void volume (dimensionless)
F Fan power requirement (kWh/yr)
P
g Gravitational constant
HP Horsepower
HRS Operating hours (h/yr)
i Interest rate
IAC Indirect annual costs ($)
Index Chemical Engineering equipment cost index (dimensionless)
k Kozeny–Carman coefficient (approx 5 for 0.8 ≥ε)
K Kozeny permeability coefficient
K Resistance of the fabric (in. H O/ft/min)
1 2
K Cake–fabric–filter resistance coefficient
2
3
L Inlet solids concentration (lb /ft )
m
M e Moisture content (vol %)
µ Viscosity
µ Fluid viscosity
f
n Equipment life (yr)
P Mechanical shaking power requirement (kWh/yr)
ms
∆P Pressure drop (in. H O)
2
∆P Pressure drop across fabric (in. H O)
1 2
∆P 2 Change in pressure drop due to cake build–up over time interval t (in. H O)
2
ρ Density
ρ True density of solid material (lb /ft )
3
p m
3
Q Volumetric flow rate (ft /min)
S Specific surface area per unit volume of either porous filter media or
2
3
solids in cake layer (ft /ft )
t Time (min)