Page 221 - Design and Operation of Heat Exchangers and their Networks

210 Design and operation of heat exchangers and their networks

2:131
θ ds
A sb ¼ 1 πd s δ sb =2 ¼ 1 π 0:336 0:0044=2
2π 2π
¼ 0:00155 m 2
The baffle hole-to-tube leakage area can be calculated with Eq. (5.29):
π 2 2
A bt ¼ ð d o + δ bt Þ d N t 1 F w Þ
ð
o
4
π 2 2 2
¼ ð 0:019 + 0:0008Þ 0:019 104 1 0:1782ð Þ ¼ 0:002084m
4
The shell-to-tube bundle bypass area is evaluated with Eq. (5.30):
∗ 2
A bp ¼ l bc δ st + N tp δ tp ¼ 0:279 0:01125 + 2 0:0095ð Þ ¼ 0:008439 m
The leakage area ratios used for correction of the effects of tube-
to-baffle and baffle-to-shell leakages are defined by Eqs. (5.58), (5.59):

ð
r s ¼ A sb = A sb + A bt Þ ¼ 0:00155= 0:00155 + 0:002084ð Þ ¼ 0:4265
ð
r lm ¼ A sb + A bt Þ=A sc ¼ 0:00155 + 0:002084ð Þ=0:03209 ¼ 0:1132
The bypass area ratio and the ratio for correction of the effects of bundle
and pass partition bypasses are defined by Eqs. (5.64), (5.65), respectively:

r b ¼ A bp =A sc ¼ 0:008439=0:03209 ¼ 0:2630
r ss ¼ N ss =N rc ¼ 1=9 ¼ 0:1111

In the window section, the number of tubes in one window section is
given by
N tw ¼ F w N t ¼ 0:1782 104 ¼ 18:53
We also obtain the number of effective tube rows in the windows
section as

ð
0:8 l c d s d ctl Þ=2Š
½
N rw ¼ int
s l

½
0:8 0:0867 0:336 0:3058Þ=2Š
ð
¼ int ¼ 3
0:01768
The shell-side flow area in the window section is calculated with
Eq. (5.25):
1 2 π 2
A sw ¼ d θ ds sinθ ds Þ N tw d o
ð
s
8 4
1 2 π 2 2
¼ 0:336 2:131 sin 2:131ފ 18:53 0:019 ¼ 0:01287m
½
ð
8 4