Geoscience Reference
In-Depth Information
Calculate the Reynolds number,
N
Re
o
, using Equation 18.12:
vd
v
gr
d
N
Re
o
=
g
where
N
Re
o
= Reynolds number for the liquid droplet at the throat inlet (dimensionless).
v
gr
= Gas velocity in the throat (cm/s).
d
d
= Droplet diameter (cm).
v
g
= Gas kinematic viscosity, (cm
2
/s).
vd
v
(9000 cm/s)(0.008 cm)
cm /s
gr
d
N
o
=
=
= 360
Re
2
0.
g
Calculate the drag coefficient for the liquid at the throat entrance,
C
D
, using Equation 18.11:
C
D
= 0.22 +(24/
N
Re
o
)[1 + 0.15(
N
Re
o
)
0.6
]
where
C
D
= Drag coefficient for the liquid at the throat entrance (dimensionless).
N
Re
o
= Reynolds number for the liquid droplet at the throat inlet (dimensionless).
C
D
= 0.22 + (24/
N
Re
o
)[1 + 0.15(
N
Re
o
)
0.6
] = 0.22 + (24/360)[(1 + 0.15(360)
0.6
] = 0.628
Now calculate the parameter characterizing the liquid-to-gas ratio
B
, using Equation 18.8:
p
pC
l
gD
BLG
=
(
/
)
where
B
= Parameter characterizing liquid-to-gas ratio (dimensionless).
L
/
G
= Liquid-to-gas ratio (dimensionless).
p
l
= Liquid density (g/cm
3
).
p
g
= Gas density (g/cm
3
).
C
D
= Drag coefficient for the liquid at the throat entrance (dimensionless).
=
3
p
pC
1000 kg/m
(1.0
= 143
l
gD
BLG
=
(
/
)
(.
0 0009
)
.
3
kg/m )(0.628)
The geometric standard deviation (σ
gm
) is 2.5, and overall penetration (
P
t
*
) is 0.008. The collection
efficiency can be calculated as follows:
η
= 1 -
P
t
*
= 1 - 0.008 = 0.992 = 99.2%
Finally, determine whether the local regulations for particulate emissions are being met. The local
regulations state that the particulate emissions cannot exceed 10 kg/hr. The required collection
efficiency can be calculated by using the following equation:
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