Coker A.K. Fortran Programs for Chemical Process Design, Analysis, and Simulation
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Heat Transfer 617
Pressure Drop (AP)
(9) From the fluid Reynolds number, Re~, obtain the friction factor,
f+, from Figure 8-12. A regression method of Figure 8-12 shows that for
Re~ < 500,
0.11183
f+ = (8-46)
0.59246
Re+
Table 8-8
Tube Count for 1-in. OD Tubes on 11/4-in. 0 Pitch
Tube Count for 1-in. OD Tubes on 1V4-in. <> Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 6 1 2 4 6 1 2 4 6 2 4 6 8
33.00 495 478 472 477 460 448
35.00 556 552 538 540 526 508
37.00 632 613 598 608 588 568
39.00 705 685 672 674 654 640
42.00 822 799 786 788 765 756
45.00 946 922 912 910 885 866
48.00 1079 1061 1052 1037 1018 1000
51.00 1220 1159 1176 1181 1160 1142
54.00 1389 1359 1330 1337 1307 1292
60.00 1714 1691 1664 1658 1626 1594
440 424
498 484
562 548
630 620
744 728
872 852
1002 980
1138 1116
1292 1264
1604 1576
Tube Count for 1-in. OD Tubes on 11/4-in. [] Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type
U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 6 1 2 4 6 1 2 4 6 2 4 6 8
5.047 9 6 4 5 4 4 - 5 4 4 - 0 0
6.065 12 12 12 12 6 4 - 12 6 4 - 4 4
7.981 22 20 16 21 16 16 12 17 12 8 12 12 8
10.02 38 38 32 32 32 32 18 30 30 16 18 24 20
12.00 56 56 52 52 52 44 24 52 48 42 24 38 36
13.25 69 66 66 61 60 52 50 61 56 52 50 52 48
15.25 97 90 88 89 84 80 64 85 78 62 64 72 68
17.25 129 124 120 113 112 112 96 108 108 104 96 98 96
19.25 164 158 148 148 144 140 114 144 136 130 114 128 124
21.25 202 191 184 178 178 172 156 173 166 154 156 166 156
23.25 234 234 222 216 216 208 192 217 208 194 192 200 196
25.00 272 267 264 258 256 256 212 252 240 230 212 240 232
27.00 328 317 310 302 300 296 260 296 280 270 260 284 276
29.00 378 370 370 356 353 338 314 345 336 310 314 332 332
31.00 434 428 428 414 406 392 368 402 390 366 368 290 384
33.00 496 484 484 476 460 460 420 461 452 432 420 442 436
35.00 554 553 532 542 530 518 484 520 514 494 484 254 248
37.00 628 621 608 602 596 580 550 588 572 562 548 574 560
39.00 708 682 682 676 649 648 625 661 640 624 620 644 628
42.00 811 811 804 782 780 768 730 776 756 738 724 758 748
45.00 940 931 918 904 894 874 850 900 882 862 844 872 868
48.00 1076 1061 1040 1034 1027 1012 980 1029 1016 984 972 1002 988
51.00 1218 1202 1192 1178 1155 1150 1125 1170 1156 1126 1114 1146 1140
54.00 1370 1354 1350 1322 1307 1284 1262 1310 1296 1268 1256 1300 1288
60.00 1701 1699 1684 1654 1640 1632 1585 1641 1624 1598 1576 1620 1604
Courtesy of TEMA.
618
Fortran Programs for Chemical Process Design
for Re~ > 500,
0.1159 (8-47)
f~
ReO.18597
The shell side pressure drop, AP~, is"
AP - t
f~. G~ 2(_ ID/12 ) .. gl 91D~)~(N+I) }(N)
Table 8-9
Tube Count for 11/4-in. OD Tubes on 19/16-in.
A
Pitch
(8-48)
Tube Count for 11/4-in. OD Tubes on 1o/16-in. ~ Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type
U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 6 1 2 4 6 1 2 4 6 2 4 6
5.047 7 4 4 0 0 0 - 0 0
6.065 8 6 4 7 6 4 - 0 0
7.981 19 14 12 14 14 8 - 6 4
10.02 29 26 20 22 20 16 14 12
12.00 42 38 34 37 36 28 22 22 20
13.25 52 48 44 44 44 36 28 32 28
15.25 69 68 60 64 62 48 45 48 44
17.25 92 84 78 85 78 72 69 64 60
19.25 121 110 104 109 102 96 86 86 80
21.25 147 138 128 130 130 116 112 114 104
23.25 174 165 156 163 152 144 130 138 132
25.00 196 196 184 184 184 172 164 162 152
27.00 237 226 224 221 216 208 196 196 184
29.00 280 269 256 262 252 242 228 232 220
31.00 313 313 294 302 302 280 270 268 256
33.00 357 346 332 345 332 318 305 310 296
35.00 416 401 386 392 383 364 357 356 344
37.00 461 453 432 442 429 412 407 404 388
39.00 511 493 478 493 479 460 449 452 440
42.00 596 579 570 576 557 544 512 534 522
45.00 687 673 662 657 640 628 596 626 612
48.00 790 782 758 756 745 728 696 720 700
51.00 896 871 860 859 839 832 820 822 800
54.00 1008 994 968 964 959 940 892 930 908
60.00 1243 1243 1210 1199 1195 1170 1116 1160 1140
Tube Count for 11/4-in. OD Tubes on 11h6-in. [] Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 1 2 4 6 1 2 4 6 2 4 6
5.047 4 4 4 0 0 0 0 0 0 0 0 0 0
6.065 6 6 4 6 6 4 0 6 6 4 0 0 0
7.981 12 12 12 12 12 12 0 12 12 4 0 6 4
10.02 24 22 16 21 16 16 12 21 12 8 12 12 8
12.00 37 34 32 32 32 32 18 29 28 16 18 20 20
13.25 45 42 42 38 38 32 24 38 34 34 24 28 28
15.25 61 60 52 52 52 52 48 52 48 44 48 42 36
17.25 80 76 76 70 70 68 50 70 66 56 50 56 56
19.25 97 95 88 89 88 88 80 85 84 70 80 74 68
21.25 124 124 120 112 112 112 96 108 108 100 96 98 96
23.25 145 145 144 138 138 130 114 136 128 128 114 124 120
25.00 172 168 164 164 164 156 136 154 154 142 136 140 136
Courtesy of TEMA.
Heat Transfer 619
where G S = lb/ft2hr and fs = g/gw = 1
g = acceleration due to gravity, 4.18 x 108 ft/hr 2
9 = density, lb/ft 3
N~ = number of shells per unit
Alternatively, AP~ can be expressed as"
AP
- { f~" G~" (ID/12)" (N + 1)}(N )
Table 8-10
Tube Count for 11/4-in. OD Tubes on 19/16-in. I-] Pitch
(8-49)
Tube Count for 11/4-in. OD Tubes on 1he-in. [] Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 6 1 2 4 6 1 2 4 6 2 4 6 8
27.00 210
202 202
193 184 184 172 184 180 158 172 176 176
29.00 241 234 230
224 224
216 198 217 212 204 198 200 196
31.00 272 268 268 258 256 256 236 252 248 234 236
232 232
33.00 310 306 302 296 296 282 264 289 276 270 264 272 268
35.00 356 353 338 336 332 332 304 329 316 310 304 312 296
37.00 396 387 384 378 370 370 358 372 368 354 340 348 348
39.00 442 438 434 428 426 414 408 420 402 402 392 396 392
42.00 518 518 502 492 492 484 464 485 476 468 464 472 456
45.00 602 602 588 570 566 556 544 565 554 546 544 552 536
48.00 682 681 676 658 648 648 620 653 636 628 620 628 620
51.00 770 760 756 742 729 722 712 738 726 720 705 712 708
54.00 862 860 856 838 823 810 804 837 820 812 804 808 804
60.00 1084 1070 1054 1042 1034 1026 1008 1036 1028 1012 1008 1012 992
Tube Count for 11/4-in. OD Tubes on 19/1s-in.
0
Pitch
TEMA TEMA TEMA TEMA
Type L or M Type P Type S Type U
Fixed Outside Packed Inside
Tubesheet Floating Head Floating Head U-Tube
Shell No. of Passes No. of Passes No. of Passes No. of Passes
ID in. 1 2 4 6 1 2 4 6 1 2 4 6 2 4 6 8
5.047 5 4 4 0 0 0
6.065 6 6 4 5 4 4
7.981 13 10 8 12 10 8
10.02 24 20 16 21 18 16
12.00 37 32 28 32 28 28
13.25 45 40 40 37 34 32
15.25 60 56 56 52 52 48
17.25 79 76 76 70 70 64
19.25 97 94 94 90 90 84
21.25 124 116 112 112 108 104
23.25 148 142 136 140 138 128
25.00 174 166 160 162 162 156
27.00 209 202 192 191 188 184
29.00 238
232 232
442 430 416
31.00 275 264 264 261 249 244
33.00 314 307 300 300 286 280
35.00 359 345 334 341 330 320
37.00 401 387 380 384 372 360
39.00 442 427 424 428 412 404
42.00 522 506 500 497 484 472
45.00 603 583 572 575 562 552
48.00 682 669 660 660 648 640
51.00 777 762 756 743 728 716
54.00 875 857 850 843 822 812
60.00 1088 1080 1058 1049 1029 1016
0 0
0 0
4 4
12 12
20 20
26 24
40 36
56 52
74 68
96 88
120 112
142 136
170 164
200 192
228 220
268 256
306 296
346 336
390 380
456 448
542 528
618 604
708 692
802 784
1010 984
Courtesy of TEMA.
620
Fortran Programs for Chemical Process Design
O
FLOW L
-~r O
SQUARE (90 ) ROTATED SQUARE (45 )
PT PT
/
FLOW
OTATED
/ ~
TRIANGULAR
(600)
TRIANGULAR (30)
Figure 8-10. Tube layouts.
where G~ = lb/ft2hr and
~)t = W~W =
1
s = specific gravity
N = number of baffles
N~ = number of shells per unit.
If AP~ is unacceptable, assume a new baffle spacing.
(10) The overall heat transfer coefficient, U, is:
1 Btu
U - 1 1 ' hrft 2 ~ (8-50)
+--+FT+F ~
hio ho
(ll)
The outside area of the heat exchanger unit A, ft 2 can be
expressed as:
a (ODt /
- .~.n.N .L (8-51)
12 ~
(12) Heat load on unit Q, Btu/hr, is:
Q = U.A.At (8-52)
. ~',~ \ ~ .
' Xl
, \
° !
i
A\I
:!,:5
I1
"l
~ .~ -
o o
~ ~
..~
o
\,
[
t.s9
t-
c~
"O
~.
c~
',r--
',l'--
t,n
I
!
I
r
• o
o_
..Q
(~
..Q
'0
¢-
q~
c
0
ffJ
~2
"0
-,~
N
¢-
0
t~
c-
O
CO
.=
-j
O3
I.I.
o
622
Heat Transfer 623
Fouling
The scale or fouling resistances represent a necessary safety factor
that increases the surface of the heat exchanger. This enables the full
process duty requirements to be attained between cleaning periods. When
an exchanger is first placed in operation there is no dirt or scale on the
tubes; consequently, the overall resistance consists of the two film and
the tube wall resistances. During operation, dirt or scale accumulates on
the surface of the tubes and the overall heat transfer rate decreases as
the dirt buildup increases. The rate of this scale or dirt depends on the
cleanliness or fouling tendencies of the process fluids.
The fouling experienced in most CPI operations are due to:
Crystallization.
When salts having an inverse solubility characteris-
tic precipitate on a heat transfer surface hotter than the flowing fluid.
Sedimentation.
Caused by deposits of particulate matter such as clay,
sand, or rust.
Corrosion.
When the heat transfer surface material reacts with the
fluid to yield corrosion deposits.
Chemical
reaction product buildup.
Caused by organic products
and polymers. The surface temperature and presence of reactants, particu-
larly oxygen, can have a very significant effect on the rate of accumulation.
Coking. On high temperature surface results in hydrocarbon deposits.
Biofouling.
Deposits formed when biological mechanisms attach and
grow on the heat transfer surface. Untreated cooling water systems are
particularly susceptible to biofouling.
The range of overall heat transfer coefficients (U) is about 10 - 200
Btu/hr
ftZ~
Table 8-11 lists the U-values for various types of equip-
ment, and fouling factors of some flowing media are shown in Table 8-12.
Table 8-13 illustrates a heat exhanger specification form. Factors gov-
erning the selection of process fluids in the tube and shell sides of an
exchanger are illustrated in Table 8-14.
Nomenclature
A - outside area of the heat exchanger unit,
ft 2
a t -" flow area,
ft 2
(text continued on page 628)
Table 8-11
Ranges of Overall Heat Transfrer Coefficients
in Various Types of Exchangers
[U Btu/hrft2~
Equipment
Process
Shell-and-tube exchanger
Double-pipe exchanger
Irrigated tube bank
Plate exchanger
Spiral exchanger
liquid-condensing steam
Compact exchanger
Stirred tank, jacketed
Stirred tank, coil inside
gas ( 1 atm)-gas ( 1 atm)
gas (250atm)-gas (250atm)
liquid-gas (1 atm)
liquid-gas (250atm)
liquid-liquid
liquid-condensing vapor
gas ( 1 atm)-gas ( 1 atm)
gas (250atm)-gas (250atm)
liquid-gas (250atm)
liquid-liquid
water-gas ( 1 atm)
water-gas (250atm)
water-liquid
water-condensing vapor
water-gas (1 atm)
water-liquid
liquid-liquid
gas (1 atm)-gas (1 atm)
gas ( 1 atm)-liquid
liquid-condensing steam
boiling liquid-condensing steam
water-liquid
liquid-condensing steam
water-liquid
1-6
25-50
2-12
35-70
25-200
50-200
2-6
25-90
35-100
50-250
3-10
25-60
50-160
50-200
3-10
60-200
120-440
160-600
2-6
3-10
90-260
120-300
25-60
120-440
90-210
Source: S. M. Walas, Chemical Process EquipmentISelection and Design, Butterworths Series
in Chemical Engineering.
624
Table 8-12
Recommended Minimum Fouling Resistances
Gases and Vapors
Fouling Factor
Centrifugal Compressor exhaust
Reciprocating Compressor exhaust
Reciprocating Compressor refrigerant vapor
Centrifugal compressor refrigerant vapor
Oil-free and clean high-quality steam
Oil-free and clean low-quality steam
Oil-bearing steam
Compressed air
Acid gas
Solvent vapors
Natural gas
0.001
0.01
0.0025
0.0015
0.0003
0.0005
0.001
0.002
0.001
0.001
0.001
Liquids
Bay water
Distilled water
Hard well water
Untreated cooling tower water
Treated cooling tower water
Engine jacket water
Treated boiler feed water
Fuel oils
Clean organic solvents
Vegetable oils
Refrigerant liquids
Industrial heat transfer oils
Hydraulic fluid
Natural gasoline and liquefied petroleum gases
Rich oil
Lean oil
0.0025
0.0005
0.0033
0.0033
0.0015
0.0012
0.0015
0.006
0.001
0.004
0.001
0.001
0.001
0.001
0.001
0.002
625
Table 8-13
Heat Exchanger Specification Sheet (Courtesy of Procede)
Heat Exchanger data sheet
(PROCEDE)
Equipment No.(Tag)
Descript. (Func.)
SIZE
SHELLS PER UNIT
SURFACE PER UNIT
FLUID CIRCULATING
TOTAL FLUID ENTERING
VAPOUR
LIQUID
STEAM
WATER
NON-CONDENSABLES
FLIYID VAPOURISED OR CONDENSED
SPECIFIC GRAVITY LIQUID
Mol Wt VAPOUR
Mol Wt NON-CONDENSABLES
VISCOSITY LIQUID
LATENT HEAT
SPECIFIC HEAT
THERMAL CONDUCTIVITY
TEMPERATURE
OPERATING PRESSURE
Sheet
N 9. ,
No. OF PASSES
FOULING RESISTANCE
TRANSFER RATE SERVICE
DESIGN PRESSURE
TEST PRESSURE
DESIGN TEaMPERATURE
METAL TEMPERATURE
Operating Data
HORIZONTAL CONNECTED IN (parallel or
series)
SURFACE PER SttELI
.... I
[
Performance of one Unit
SHELL
SIDE
...... 7-- -r
TUBE
SIDE
OUT
I
I 111 I [. II[
AU.OW I CALC I 1 AU,OW I [ C~.C.
Construction of one Shell
OUT
II
12
9
13
14
9
15
16
17
18
19
9 20
'21
j
22
, ,
123
[
25
26
27
29
3O
~31
TUBES
SHELL
C~L
BAFFLES CROSS
TUBE SUPPORTS
LONG BAFFLE
IMPINGEMENT BAFFLE
, .
TYPE OF JO]2~rl "
GASKETS SHELL IN
CONNECTIONS SHELL IN
CONNECTIONS CHANNEL IN
CORROSION ALLOWABLE SHELL SIDE
EXPANSION BELLOWS
DESIGN CODE
INSPECTION
WEIGHT OF ONE UNIT EMPTY
DATE OF ORDER
INSPECTION ,FHTrlNG ATTACHM NT, BY
Checked
I-- Approved
,, ,
Date Ensineetin8
Service
I...
Proeem
No. OD ]THICKNESS ] [ LENGTtt [ I I PITCH
I.D. SHELL COVER
FLTNG HEAD COVER
...... FLOATING
TYPE SPACING % CUT
SPACING
TYPE SEAL
SEAL STRIPS
TUBE ATTACHM'r
FLOATING HEAD
INTERCONN SHELL OUT
INTERCONN CHANNEL OUT
TUBE SIDE
BOLTS NUTS
S.R.
PAINTING INSULATION
OPERATING DATE OF ENQ__UIRY __
ORDER No.
DRG. No. .56
t MANUFACTURER ~ 57
3 6
2 5
1 4 .60
REV By . . Aizar. REV By . Date . 61
Company
Address
AI~.
35
36
37
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39
9 40
41
42
43
44
9
45
46
9
47
48
9
49
50
9
51
52
.53
54
55
9 58
59
62
Equipment
No.
Project No.
64
626