HEAT EXCHANGER DESIGN CALCULATION
SHELL SIDE DATA Mass Flowrate, ms (lb/hr) =
4000
o
Inlet Temperature, T1 ( F) =
205
o
Outlet Temperature, T2 ( F) =
264
Inlet Pressure, Ps (psig) =
1 80 2o
Fouling Allowance, fs (hrft F/Btu) =
0.002
Allowable Pressure Drop, dPs (psi) =
5
PHYSICAL PROPERTIES OF SHELL SIDE FLUID INLET MEAN o
OUTLET
Temperature ( F)
205
234.5
264
o
Sp. Heat (Btu/lb F)
0.58
0.595
0.61
2o
0.072
0.07
0.068
3
41.2 0.284
40.6 0 .2 6 0 5
40 0.237
k (Btuft/hrft F) Density (lb/ft ) Viscosity (cp)
TUBE SIDE DATA Mass Flowrate, mt (lb/hr) =
590
o
Inlet Temperature, t1 ( F) =
620
o
Outlet Temperature, t2 ( F) =
250
Inlet Pressure, Pt (psig) =
65 2o
Fouling Allowance, f t (hrft F/Btu) =
0.005
Allowable Pressure Drop, dPt (psi) =
5
PHYSICAL PROPERTIES OF TUBE SIDE FLUID INLET MEAN o
OUTLET
Temperature ( F)
6 20
435
25 0
o
0.76
0.6615
0 .5 6 3
0.045
0.055
0 .0 6 5
42 0 .4
46.3 1 .3
50.6 2.2
Sp. Heat (Btu/lb F) 2o
k (Btuft/hrft F) 3
Density (lb/ft ) Viscosity (cp)
CALCULATIONS
HEAT DUTY
Q S (Btu/hr) =
140420
Q t (Btu/hr) = 144405.5 LMTD o
LMTD ( F) = 150.3673 R=
6.2711864
FT =
0.7365
0.736501
S = 0.142169 From Fig. 12.19
o
Corrected LMTD ( F) = 110.7455 ESTIMATE LAYOUT Material use for Shell = Material use for Tubes =
Carbon Steel Carbon Steel
Tube Outer Diameter (in) = Tube Length (ft) = Pitch (in) =
0.75 8 1
Tube Inner Diameter (in) =
0.5837
ESTIMATE OVERALL HEAT TRANSFER COEFFICIENT 2o
Uo (Btu/hrft F) =
6.78
NUMBER OF TUBES 2
Ao (ft ) = 187.0135 2
Area of One tube (ft ) = 1.570795 Number of Tubes = 119.0566 = 119 Number of Tubes per pass =
59
2
Tube cross-section area (ft ) = 0.001858 2
So, Area per pass (ft ) = 0.109638 3
Volumetric Flowrate (ft /s) =
0.00354
Tube Side Velocity (ft/s) = 0.032286
Shell pass = Tube pass =
From Table 12.3
1 2
BUNDLE & SHELL DIAMETER K1 =
n1 =
0.156
2.291
From Table 12.4
Bundle Diameter (in) = 13.58975 Bundle-Shell Clearence (in) =
2
Shell Diameter (in) =
12
From Fig. 12.10
TUBE SIDE HEAT TRANSFER COEFFICIENT Reynolds Number = 83.20359 Prandtl Number = 37.8378 Length Diameter Ratio = 164.468 Jh Factor =
0.07
From Fig. 12.23
Nusselt Number = 19.31771
2o
hi (Btu/hrft F) = 21.84288 BAFFLE SPACING & SHELL SIDE VELOCITY Baffle Spacing (in) = 2
As (ft ) =
2.8 0.058333
3
Volumetric Flowrate (ft /s) = 0.027367 Shell Side Velocity (ft/s) = 0.469153 SHELL SIDE HEAT TRANSFER COEFFICIENT Equivalent Diameter (in) = 0.945621 Reynolds Number = 8571.481 Prandtl Number = 5.358485 Jh Factor = 2o
0.015
hs (Btu/hrft F) = 198.7437
From Fig.12.29
CALCULATED OVERALL HEAT TRANSFER COEFFICIENT o
kw (Btu/hrft F) =
30
From Table 2-3 Ken Arnold Vol:2
2o
Uo (Btu/hrft F) = 13.78507 TUBESIDE PRESSURE DROP 2
Pt = Np x (8 x jf x (L/di) + 2.5)(ρ x v /2) L (m) = di (m) =
2.439024 jf = 0.01483 Np = 3
ρ (Kg/m ) = v (m/s)=
0.095 2
741.263 0.009843
Pt =
9.156678 Pa 0.0013284 psi SHELL SIDE PRESSURE DROP 2
Ps = 8 x jf x (Ds/de) x (L/lB) x (ρ x v /2) L (m) =
2.439024 jf =
lB (m) =
0.071138 Ds (in) =
0.304878
650.006 de (in) = 0.143035
0.024025
3
ρ (Kg/m ) = v (m/s)= Ps =
1157.1946 Pa 0.1678832 psi
0.05
INPUT BOXES
HEAT EXCHANGER DESIGN CALCULATION
SHELL SIDE DATA Mass Flowrate, ms (lb/hr) =
4000
o
Inlet Temperature, T1 ( F) =
205
o
Outlet Temperature, T2 ( F) =
264
Inlet Pressure, Ps (psig) =
180 2o
Fouling Allowance, fs (hrft F/Btu) =
0.002
Allowable Pressure Drop, dPs (psi) =
5
PHYSICAL PROPERTIES OF SHELL SIDE FLUID INLET MEAN o
OUTLET
Temperature ( F)
205
234.5
264
o
Sp. Heat (Btu/lb F)
0.58
0.595
0.61
2o
0.072
0.07
0.068
3
41.2 0.284
40.6 0.2605
40 0.237
k (Btuft/hrft F) Density (lb/ft ) Viscosity (cp)
TUBE SIDE DATA Mass Flowrate, mt (lb/hr) =
590
o
Inlet Temperature, t1 ( F) =
620
o
Outlet Temperature, t2 ( F) =
250
Inlet Pressure, Pt (psig) =
65 2o
Fouling Allowance, f t (hrft F/Btu) =
0.005
Allowable Pressure Drop, dPt (psi) =
5
PHYSICAL PROPERTIES OF TUBE SIDE FLUID INLET MEAN o
OUTLET
Temperature ( F)
620
435
250
o
0.76
0.6615
0.563
0.045
0.055
0.065
42 0.4
46.3 1.3
50.6 2.2
Sp. Heat (Btu/lb F) 2o
k (Btuft/hrft F) 3
Density (lb/ft ) Viscosity (cp)
CALCULATIONS
HEAT DUTY
Q S (Btu/hr) =
140420
Q t (Btu/hr) = 144405.5 LMTD o
LMTD ( F) = 150.3673 R = 6.271186 FT =
S = 0.142169
0.7365 o
Corrected LMTD ( F) =
From Fig. 12.19 169
ESTIMATE LAYOUT Material use for Shell = Material use for Tubes =
Carbon Steel Carbon Steel
Tube Outer Diameter (in) = Tube Length (ft) = Pitch (in) =
0.75 8 1
Tube Inner Diameter (in) =
0.5837
ESTIMATE OVERALL HEAT TRANSFER COEFFICIENT 2o
Uo (Btu/hrft F) =
6.78
NUMBER OF TUBES 2
Ao (ft ) = 122.5498 2
Area of One tube (ft ) = 1.570795 Number of Tubes = 78.01769 = 78 Number of Tubes per pass =
39
2
Tube cross-section area (ft ) = 0.001858 2
So, Area per pass (ft ) = 0.072472 3
Volumetric Flowrate (ft /s) =
0.00354
Tube Side Velocity (ft/s) = 0.048842
Shell pass = Tube pass =
From Table 12.3
1 2
BUNDLE & SHELL DIAMETER K1 =
n1 =
0.156
2.291
From Table 12.4
Bundle Diameter (in) = 11.30151 Bundle-Shell Clearence (in) =
2
Shell Diameter (in) =
12
From Fig. 12.10
TUBE SIDE HEAT TRANSFER COEFFICIENT Reynolds Number = 125.8721 Prandtl Number = 37.8378 Length Diameter Ratio = 164.468 Jh Factor =
0.07
From Fig. 12.23
Nusselt Number = 29.22423
2o
hi (Btu/hrft F) = 33.04436 BAFFLE SPACING & SHELL SIDE VELOCITY Baffle Spacing (in) = 2
As (ft ) =
2.8 0.058333
3
Volumetric Flowrate (ft /s) = 0.027367 Shell Side Velocity (ft/s) = 0.469153 SHELL SIDE HEAT TRANSFER COEFFICIENT Equivalent Diameter (in) = 0.945621 Reynolds Number = 8571.481 Prandtl Number = 5.358485 Jh Factor = 2o
0.015
hs (Btu/hrft F) = 198.7437
From Fig.12.29
CALCULATED OVERALL HEAT TRANSFER COEFFICIENT o
kw (Btu/hrft F) =
30
From Table 2-3 Ken Arnold Vol:2
2o
Uo (Btu/hrft F) = 19.01084 TUBESIDE PRESSURE DROP 2
Pt = Np x (8 x jf x (L/di) + 2.5)(ρ x v /2) L (m) = di (m) =
2.439024 jf = 0.01483 Np =
0.095 2
3
ρ (Kg/m ) = 741.263 v (m/s)= 0.014891 Pt = 20.95621 Pa 0.00304 psi SHELL SIDE PRESSURE DROP 2
Ps = 8 x jf x (Ds/de) x (L/lB) x (ρ x v /2) L (m) =
2.439024 jf =
lB (m) =
0.071138 Ds (in) =
0.304878
ρ (Kg/m ) = 650.006 de (in) = v (m/s)= 0.143035
0.024025
3
Ps = 1157.195 Pa 0.167883 psi
0.05
