proplem difinition
DESCRIPTION
PROPLEM DIFINITION. - PowerPoint PPT PresentationTRANSCRIPT
Heat exchanger is a device used to transfer heat from a fluid (liquid or gas) to another fluid where the two fluids are physically separated. The Shell and Tube is the most common type of heat exchanger used in the process, petroleum, and chemical industries, it contains a number of parallel u-tubes inside a shell.
Heat exchanger E-104 is shell and tube (horizontal) heat exchanger with change phase in the tube side by condensate the flow of this stream .In the shell side there are benzene but in the tube there are all water
E-104 is operated in the shell in this condition.
Flow rate 4.95E+04 Kg/h Inlet Temperature ,T1 25 oC Outlet Temperature ,T2 165.1 oC Heat Capaxcity of inlet stream, Cpin 1.5196 KJ/kg°C Heat Capacity of outlet stream, Cpout 2.1685 KJ/kgoC Average Heat Capacity, Cpavg 1.84405 KJ/kgoCMass Density of inlet stream , ρin 872.83 kg/m3
Mass Density of outlet stream , ρout 156.51 kg/m3
Average Mass Density, ρavg 514.67 kg/m3
Average Viscosity of stream, µavg 0.606 mNs/m2
Average Thermal conductivity, Kf 0.131 W/moC
And the tube side is operated in these conditions
Flowrate 4.32E+00 Kg/s
Average Heat Capacity, Cp 2.197 kJ/kgoC
Average Mass Density, ρ 2.16 kg/m3
Average Viscosity of stream, µ 0.028 mNs/m2
Average Thermal conductivity of stream, Kf 0.068 W/moC
inlet Temperature , t1 500 oC
outlet Temperature, t2 151.8 oC
Materials of construction:
I checked in the materials compatibility program I found that with cresol the suitable materials is carbon steel because medium corrosion.
The main functions of heat exchanger E-104 are to controlled the feed temperature of the distillation (T-100) , by increase it from 25to 165.1 for the first and decrease it from 500C to 151.8C respectively
Insulation:
The insulation material for E-104 is mineral wool (10.0) according to this figure. Since the highest temperature is 500C .
lmtm
lm
TFT
tT
ttS
tt
TTR
tTtT
tTtTT
11
12
12
21
12
21
1221
;
ln
Exchanger Type and Dimension
T1 C 25
T2 C 165.1
t1 C 500
t2 C 151.8
∆Tlm C 214.26
R - 0.4
S - 0.733
Ft= 0.79 From Fig.12.20
∆Tm 169.27 C
Heat Transfer AreaU= 500 W/m2.C
∆Tm 169.27 C
Q= 3549.9 KW
A= 41.94 m2
Assume Outler diameter (do) 50 mm
Assume inside diameter (di) 46 mm
Assume Length of tubes (L) 4.88 m
tringual Pitch =1.25* dia. 57.5 mm
Assume 4 tube passes
Area of one tube m2 0.766# of tubes 55Tubes/Pass 14
Cross sectional area Mm2 1661.9Area/pass Mm2 415.47Velocity m/s 87.9
From table 12.4 K1 0.175 n1 2.285
Tube side Heat Transfer Coefficients
Re 3.07*10^5
Pr 9.22*!0^-2
where jh is the heat transfer factor , assume that the viscosity of the fluid is the same as at the
wall : (µ/µwall) = 1(hi di / kf) = jh Re Pr0.33 * (µ/µwall)0.14
Shell side heat Transfer Coefficient:
de / (1/3)Pr^* Re*jh * kf hs
_Re,
Pr;Re
917.01.1 22
cutbufflefj
k
cdu
dpd
d
A
FlowRateu
p
lDdpA
h
pes
oto
e
ss
t
Bsots
Assume: lb = .05*Ds
As 0.016007
m2
de 35.5 mmus 1.667 m/s
Assume: baffle cut is 25% , then get jh from figure 12.29
Re 5*10^4jh 2.90E-
03
Overall Coefficient:
ii
o
w
i
oo
oo hd
d
k
ddd
hodhU
1
2
ln111
Assume Kw = 45 W/m.C (for carbon stainless steel) (from figure 12.6)
ho 1100.67 W/m^2.C
hi 1674 W/m^2.C
hod 5000 W/m^2.C
1/Uo 0.002017
C.m2/W
Uo 495.78 W/C.m2
For fouling factor (hod) from table 12.25
Tube Side pressure drop
ΔPt = Np [ 8jf (L/di)(µ/µw)^(-m) +2.5 ] ρut²/2Where ΔPt is tube side pressure drop Np is number of tube side passesUt is tube side velocity L length of one tube Neglecting the viscosity correction term, (µ/µw) = 1
Pressure Drop 24948.538
Pa
Thickness:
t = (Pri/(SEJ-0.6P))+CcWhere:t = shell thickness (in)P = Maximum allowable internal pressure (psig)ri = internal radius of shell before allowance corrosion is added (in)EJ = efficiency of jointsS = working stress (psi)Cc = allowance for corrosion (in)
ri =12.45245
458 inP = 587.8 psiS = 13706.66 psiEJ = 0.85 Cc = 0.125 in
t = 0.773 int = 19.6 mm
Definition:
The Vessel V-100 is used as liquid-vapor separator in which the feed to the vessel enters with 190 oC and 3410 KPa
Metals:
The Separator is made from carbon steel because of its ability to tolerate high temperature and its low cost compare to other metals. Also, from the material compatibility program we found that with our component suitable material is carbon material is carbon steel because there is no corrosion. The range of the temperature for the carbon steel is from -20 to 600 F and our Vessel operates at 190 oC which is within the range
Stream Value UnitFeed 4573 Kgmol/hr
Overhead 337.8 Kgmol/hrBottoms 4235 Kgmol/hr
Flow rate:
Insulation:
The insulation material for our Vessel is Glass Fiber 4.0 according to this figure. Since the Vessel highest temperature is 190ºC
Diameter:Parameter Value Unit
L 3.496*10^5 kg/hr
V 26810 kg/hr
ρl 689.91 kg/m3
ρv 22.599 kg/m3
Tin 190 oC
P 34.1 Bar
Thickness:
The thickness is depending on many factors such as material type, operating temperature and the stress on the material. The following
calculations will show the value of the thickness
Parameter Value Unit CommentD 2.71 M CalculatedP 494.7 Psi Pressure at the
V-100S 13700 Psi Maximum
allowable Stress of
Carbon Steel Ej 0.85 Efficiency of
jointCc 0.125 In Allowance of
corrosion
Cost:•Cost of VesselVolum:V=A*tA=((2*r*3.14*H)+(4*3.14*r^2))
A= 189.277m2V= 11.791m3
Weight:W=V*ρ
ρ carbon steel=7900kg/m3w=93154.83kg= 205313.26ib
Cost From Matche 406000$Cost of insulation = (406000) (0.1) =40600$ Cost = 406000+40600=446600 $
Distillation is defined as a process in which a liquid or vapor mixture of two or more substances is separated into its component fractions of desired purity, by the application and removal of heat.
I checked in the materials compatibility program I found that with cresol the suitable materials is Stainless steel 304 because medium corrosion.
The thickness is depending on many factors such as material type (in my case is stainless steel) and the stress on the material.
T = 8.64mm
The insulation material for our Distillation is mineral wool (10.0) according to this figure. Since the highest temperature is 260.1C .
property Unit Top Bottom
Mwtkgmole/
kg 106.03 142.78
Vapor Flow kmol/h 3710.9 3092.1
Liquid Flow kmol/h 618.49 3119.9
surface tension N/m0.00930
120.0080
6
ru liquid kg/m3 671.54 612.07
ru vapor kg/m3 17.65 20.22
mmLiquidN
PPPlate
Dropessure
papressurebottom
papressureTop
E
NN
Nad
stagesofnumberHYSYSFrom
trayOverallassumeEAssume
AVGliquidal
topbottom
o
hysysstagesal
hysysstages
o
176606.0)805.641)(31(8.9
)583960618430(
81.9_Pr
618430
583960
318.0
251
26Re
26
8.0
Re
/Re
/
smKu
smKu
KKCorrection
KKCorrection
V
LBottomF
V
LTobF
BottomV
L
TopV
L
bottomTopiV
Lad
iv
vLBottomf
iv
vLtopf
ibottom
itop
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v
iLV
iL
v
iLV
i
iMAXi
iMAXi
ii
ii
i
/5864.022.20
22.2007.612)1083.0(
/673.065.17
65.11754.671)1106.0(
1083.002.0
)00806.0()108.0(
02.0
1106.002.0
)00930.0()129.0(
02.0
1856.007.612
22.20021.1)(
027.054.671
65.171666.0)(
021.100806.0
9.3119
016669.3710
49.618
,;Re
1)(
1)(
2.02.0
1)(1
2.02.0
1)(1
Take Tray spacing = 0.9 mAssume flooding= 85 %Assume Down comer area= 45 %
K1 "Top" = 0.129, K1 "Bottom" = 0.108
smuFloodingu
smuFloodingu
MAXii
MAXii
fBottomf
fTopf
/498.0)586.0)(85.0(%
/572.0)673.0)(85.0(%
)(
)(
smMwtmoleFlow
RateFlowVolumetric
smMwtmoleFlow
RateFlowVolumetric
iv
iiBottomi
iv
iiTopi
/3
119.6)3600)(22.20(
)78.142)(9.3119(__
/3
192.6)3600)(65.17(
)03.106)(9.3710(__
)(
)(
2)(
2)(
27.12119.6
4984.0
%
__
81.10572.0
19.6
%
__
mDowncomeru
RateFlowVolumetricArea
mDowncomeru
RateFlowVolumetricArea
i
i
f
iBottomi
f
iTopi
246.20
246.20
)4(4.01
27.2̀14
2022.18
)4(4.01
81.104
)(
)(
mBottomDMAXTakeD
mArea
D
mArea
D
c
i
Bottomi
i
Topi
28.11Re
/3
104.5)07.612)(3600(
)78.142)(9.3119(
Figuread
smMwtMoleflow
FlowVolumerticliquid
MAX
Single Pass Plate could be used