T UA Q: LMTD
T UA Q: LMTD
T UA Q: LMTD
)
Double Pipe Heat
Exchanger
Counter Current double pipe HE
The variables are almost the same
with the
Double Pipe Heat Exchanger with the
addition of T lm
L
Design variable is
Pass
Q= UA T lm
q=D
q UATlm q= total
heat transfer
U= over all heat transfer coefficient
Tlm= temperature gradient
Design veriable Log mean
temperature can be calculated by:
LMTD=
L
( Pass
)( T
lm
FT )
no of shell
no . of pass
)
shell
3.) Evaporators
T 1 T 2
T1
ln
T2
2.)
Shell and Tube Heat
Exchanger
W steam
w Cp T air =
Q=U o A o T lm F T =
wCp T air
U o A o T lm=
E
e=
V0
Crystallizers
Swenson-Walker Crystallizer
FhF=VhV+LhL+ChC
Design variables are the balances OMB,
SB and EB
4.)Humidifier/Dehumidier/Cooling
Tower
Adiabatic Humidifier
6.) Drier
Batch Drier
T 1 =T= t as = t wb
WB: w( H 2H 1 )= L2L1 = M
H LM
MTE: w( H 2H 1 =k ' a S Z
UG a S Z
HT E: w C s ( t 2 t 1 =
T LM
H
1 H 2)
H LM = (
ln ( H 1)
T LM =
5.)
T 1 T 2
T1
ln
T2
Gas Absorber
Q dx
=
Ax R
2
7.)
Cooling tower
1
H 2)
H LM = (
ln( H 1)
8.)
x
1x w
F
1
=
(ln f + m ln
)
W m1
xw
1x f
Fx F WxW
xD =
FW
10.)
Extraction/ Leaching
ln
T 1 T 2
T1
ln
T2
Filter
T LM =
9.)
2
dV P A gC
rf =
=
d c(V + V e )
2V
dV 2
= V+ e
d K
K
2( P) A 2 gC
K=
c
Distillation column
Y bY b
ln
Y aY a
N=
L'
ln
V ' Kb
11.)
Constant Stirred Tank
Reactor (CSTR)
Design variables are volume and
Average time
t=
V
V0
FA X
r A
0