Page 343 - Mechanical Engineers' Handbook (Volume 4)

332 Heat Exchangers, Vaporizers, Condensers

Wall temperature, cold fluid side F C
T w, cold
Overall heat transfer coefficient Btu/hr ft F W/m K
2
2
U o
3
V Volumetric flow rate use S.I. only m /s
Face velocity ft/min use S.I. only
V ƒ
Shellside velocity ft/hr m/hr
V s
Tubeside velocity ft/hr m/hr
V t
Air flow rate lb/min use U.S. only
W a
Flow rate, hot fluid lb/hr kg/hr
W 1
Flow rate, cold fluid lb/hr kg/hr
W 2
Flow rate, condensate lb/hr kg/hr
W c
Air-cooled bundle width ft use U.S. only
W d
Flow rate, shellside lb/hr kg/hr
W s
Flow rate, tubeside lb/hr kg/hr
W t
Martinelli parameter — —
X tt
Wall thickness ft m
x w
y Weight fraction vapor — —
Nucleate boiling suppression factor — —
Dynamic pressure loss use S.I. Pa
p d
(typically 40–60 Pa)
Two-phase friction pressure drop psi kPa
P ƒ
Liquid phase friction pressure drop psi kPa
P l
Static pressure drop, air cooler use S.I. only Pa
p s
Shellside pressure drop lb/ft 2 use U.S. only
P s
Tubeside pressure drop lb/ft 2 use U.S. only
P t
Latent heat Btu/lb J/kg
Viscosity, general lb/ft hr Pa
Viscosity, bulk fluid lb/ft hr Pa
ƒ
Viscosity, at wall lb/ft hr Pa
w
Density, liquid lb/ft 3 kg/m 3
l
Density, shellside fluid lb/ft 3 kg/m 3
s
Density, tubeside fluid lb/ft 3 kg/m 3
t
Density, vapor lb/ft 3 kg/m 3
v
Bundle vapor blanketing correction — —
b
Two-phase pressure drop correction — —
l
REFERENCES
Note: Many of the following references are taken from the Heat Exchanger Design Handbook (HEDH),
Hemisphere, Washington, DC, 1982, which will be referred to for simplicity as HEDH.
1. Standards of Tubular Heat Exchanger Manufacturers Association, 6th ed., TEMA, New York, 1978.
2. P. Paikert, ‘‘Air-Cooled Heat Exchangers,’’ Section 3.8, HEDH.
3. A. C. Mueller, in Handbook of Heat Transfer, Rohsenow and Hartnet (eds.), McGraw-Hill, New
York, 1983, Chap. 18.
4. R. L. Webb, ‘‘Compact Heat Exchangers,’’ Section 3.9, HEDH.
5. F. L. Rubin, ‘‘Multizone Condensers, Desuperheating, Condensing, Subcooling,’’ Heat Transfer Eng.
3(1), 49–59 (1981).
6. H. Hausen, Heat Transfer in Counterflow, Parallel Flow, and Crossflow, McGraw-Hill, New York,
1983.
7. D. Chisholm et al., ‘‘Costing of Heat Exchangers,’’ Section 4.8, HEDH.
8. R. S. Hall, J. Matley, and K. J. McNaughton, ‘‘Current Costs of Process Equipment,’’ Chem. Eng.
89(7), 80–116 (Apr. 5, 1982).
9. J. Taborek, ‘‘Charts for Mean Temperature Difference in Industrial Heat Exchanger Configurations,’’
Section 1.5, HEDH.