For I shell-2 tube pass exchanger

VIR+)ln -5) 1
F -RS) T-T) S
R -)
(R-1)In-S[R+I =VR+1D| (2-) (T -
2-S[R+1+ V(R +1)J
For other configurations, use the following charts

Temperature correction factor: one shell pass; two or more even tube 'passes

Temperature correction factor: two shell passes;,four or multiples of four tube passes

04 506 9

Temperature correction factor: divided-flow shell; two or more even-tube passes

1.0

FEF
0.1 0.2

Temperature correction factor, split flow shell, 2 tube pass

4. Calculate the mean temperature difference using AT. = Fi x LMTD

5. Assume overall heat transfer coefficient as initial guess from the table below:
 Table 12.i. Typical overall coefficients

Shell and tube exchangers

Hoo Muid Cold Muid U (Wm"C)

Hear exchangers
Water Water 800-1500
Organic solvents
L g h t oils
Organic solvents 100-30
1 0 0 -4 0 0

Heavy oils
Light ois
Heavy oils S0-300
Gases Gases 10- S0

Ceolers
a n i c solvents
Water 250- 750
ght ols
Heavy oils
Water
Water
350- 300
Watcr
60-
Gases
Organic solvents Bone
20 300
Water Brine
S0-SO
600- 1200
CGases Brine T5-250

Heaters
Sieam Water 1S00-4000
500-1000
Sleam
Steam
Organic sofvents 300-900
Light ols
Steam Heavy oils 6-4500
Steam
Gases
Dowtherm Heavy oils
300
Dowtherm Gases
Stcam
8ses
Flue Hydrocarbon vapours 00
0-

Condensers
Aqueous vapour Water TO00-1500
Organic vapours watcr 700- 10O0
Organics (some non-condensables) Water SO0- 70
Vacuum condensers Water 200-s00
Vaporisers
Steam Aqucous solutions I000-1S00
Steam
Steam
Light organices 900-12000
600-900
Heavy organics
Air-ceoled exchangers
PTocess fluid

Water SOD-450
Light organics
eay
Gases,
oganics
Dar
Condensing hydrocarbons s00-ou

Table 12.1. (continued)

Immersed coils
Coil Pool U (Wim°C)
Agitated
Steam Dilute aqueous solutions 800-1500
Steam Light oils 300-500
Steam Heavy oils 200-400
Water Aqueous solutions -700
Water Light oils 200-300D

Jecketed vessels
Jacket Vessel

Steam Dilute aqueous solutions S00-700D

Steam Light organics 250-500
Water Dilute aqueous solutions 200-500
Water Light organics 200- 3A0

Gasketed-plate exchangers
Ho Muid Cold fluid

Light organic Light organic 2500-5000

Hght organic Viscous organic
Viscous organic IScOus Organic TO0-200
ught organic Process waler
2500-3500
Viscous organic Process waler 250- 500
Light organic Cooling walcr 2000-4SO0
Viscous organic Cooling water 250-450
Condensing steam Light organic 2500-3500
Condensing steam Viscous organc 250-500
Process water Process walcr 5000-7500
Process water Cooling water O00-7000
Dilute aqueous solutions Cooling water SO00-7O00
Condensing steam Process water 3S00-4S00
 -

etoern,
Wim Condensaton
aqueous vapours

d
Prooes Boling aqueous
225

W/mC
2000
U,

Dilute aqueoUs coefcent,

Boiling organics
Estmated ovemil

500
Condensation organic vapours 1500

Paraffins 1250

Heavy orgarncs
Molhen sats 1000

ra
Os
high essun

Hesidue

S00
000 2500 3000 3500 4000 4500
Ar and ga
low pressure Thermal fui
lAr and ga
Brines
River, well, Hot heat Boling
waler
Condensate Sleam condensing

sea water transter o

Retrigerants

Cooling lower water Service fluid coeficient, Wmc

Hgure 12.1. Overall coefficients (join process side duty to service side and read U from centre scale)
 Table 12.6. Conductivity of metals

Metal Temperature (C) k(W/m°C)

Aluminiumm 202
100 206
Brass 97
(70 Cu, 30 Zn) 100 104
400 116
Copper 388
100 378
Nickel 62
212
Cupro-nickel (10 per cent Ni) 0-100
Monel 0-1100
Stainless steel (18/8) 0-100 16
Steel
100
600 6
Titanium 0-100 16
 Table 12.4. Constants for use in equation 12.3

Triangular pitch. ps = 1.25d,

No. asses 2 B

0.319 0.249 0.175 0.0743 0.0365

2.142 2.207 2.285 499 2.675

Square pitch, pi= 1.25d

No. passes
A .215 O.156 0.158 0.0402 0.0331
2.207 2.291 2.263 2.617 2.643

12. Provide/Assume the type of floating head of the exchanger and obtain the bundle
diameter clearance, BDC. Use the chart bellow:

00

Pul-through floating head

Spli-ing fioating head

50

Outside packed head

8/15
20

JO

Fixed and U-tube

0.4 O.6 .8 1.0 1.2

Bundle diameter, mn
0
10

cuS, percent
a

10 34
5700
10
10
0 Hoynolds number Re

I29 Shell-side hear-transier factors, segmental baffies

FHgure
10
number,
eyrolo

Figure 12M Shell-side friction factons, segmental hafmes

0
2 3 4 56789 234 5 6 789 23 4 5 6 789 2 34 5 6 789 456789
0 10 10 10 10 10
Reynolds umber, Re

Figure 12.23. Tube-side heat-ransfer factor

103 7891 7891

10 10 0
eynolds number, Re-

Figure 12.24. Tube-side friction factors

 Table 12.2. Fouling factors (coeficients), typical values
Fluid Coefficient (W/m°C) Factor (resistance) (m°CW)
River water 3000-12,000 0.0003-0.0001
Sea water 1000-3000 0.001-0.00033
Cooling waler (towers) 3000-6000 0.0003-0.00017
Towns water (soft) 3000-5000 0.0003-0.0002
Towns water (hard) 1000-2000 0.001-0.0005
Steam condensate IS00-5000 0.00067-0.0002
Steam (oil free) 4000-10,00 0.0025-0.0001
Steam (oil traces) 2000-5000 0.0005-0.0002
Refrigerated brine 3000-5000 0.0003-0.0002
Air and industrial gases SO00-10.00 0.0002-0.0001
Ffue gases 2000-5000 0.005-0.0002
Organic vapours 5000 0.0002
Organic liquids S000 0.0002
Light hydrocarbons SO00 O.0002
Heavy hydrocarbons 2000 O.0005
Boiling organics 2500 0.0004
Condensing organ ics 5000 0.0002
Heat transfer fluids S000 0.0002
Aqueous salt solutions 3000-5000 0.0003-0.0002

Table 12.3. Standard dimensions for steel tubes

Outside diameter (mm) Wall thickness (mm)

16 1.6 2.0
1.6 2.0 2.6
1.6 2.0 2.6
30 I.6 2.0 2.6 3.2
38 2.0 2.6
50 2.0 2.6

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