Environmental Engineering Reference
In-Depth Information
Table 6.4
Constants for determining H
G
and H
L
. Range of WL
L
for H
L
is
400 to 15,000 [6].
Range for
H
G
Packing
W
G
W
L
(lb
m
/
ft
2
(in)
a
G
b
c
a
L
d
·
hr)
Raschig rings
3
8
2.32
0.45
0.47
0.0018
0.46
200-500
200-500
1
7.00
0.39
0.58
0.010
0.22
200-800
400-500
1
6.41
0.32
0.51
-
-
200-600
500-4500
Berl saddles
1
2
32.4
0.30
0.74
0.0067
0.28
200-700
500-1500
1
2
0.811
0.30
0.24
-
-
200-700
1500-4500
1
1.97
0.36
0.40
0.0059
0.28
200-800
400-4500
Example 6.5: packed column
Problem:
Agas mixture of 2 mol% SO
2
(
A
) and 98 mol% dry air (
B
)istobetreated with
pure water in a packed absorption column using 1-inch Berl saddles as packing. The
exit gas should contain 0.1 mol% or less SO
2
. The column operates at 30
◦
C and
1 atm pressure. The gas and liquid fluxes in the column are
W
G
=
ft
2
250 lb
m
/
·
hr and
ft
2
W
L
=
4000 lb
m
/
·
hr. Determine the required column height, given:
Air
Water
µ
=
0
.
07 kg
/
m
·
hr
µ
=
3
.
6kg
/
m
·
hr
=
2
.
5lb
m
/
ft
·
hr
046 m
2
10
−
6
m
2
D
AB
=
0
.
/
hr
D
AB
=
6
.
1
×
/
hr
m
3
m
3
ρ
=
1
.
16 kg
/
ρ
=
997 kg
/
.
VLE equation:
y
=
26
x
.
Solution:
µ
ρ
Sc
G
=
D
G
.
/
·
0
07 kg
m
hr
=
1.16 kg
m
3
0
hr
=
1
.
3
.
/
.
046 m
2
/
µ
ρ
Sc
L
=
D
L
3
.
60 kg
/
m
·
hr
=
997 kg
m
3
6
hr
=
592
.
/
.
1
×
10
−
6
m
2
/
Search WWH ::
Custom Search