Page 273 - Pipeline Rules of Thumb Handbook

260 Pipeline Rules of Thumb Handbook

where d = density, g-moles/l Transport properties

Viscosity (liquid) 2
4
in which the constants for methane are:
t°C m, centipoises
B o = 0.042600
-185 0.226 (subcooled)
A o = 1.85500 -180 0.188
-175 0.161
C o = 22,570.0 -170 0.142
-165 0.127
b = 0.00338004
-160 0.115 (at sat. pressure)
a = 0.0494000
7
Viscosity (vapor) at 1atm pressure:
c = 2,545.00
t°C m, centipoises
g = 0.0060000
-181.6 0.00348
a = 0.000124359
-78.5 0.00760
0 0.01026
With these constants, R = 0.0820 liter-atm/(°K) (gram mole), 20 0.01087
100 0.01331
P is in atmospheres, T is in °K, and e is the base of natural
200.5 0.01605
logarithms. Constants in this equation are available for
284 0.01813
ethane, ethylene, propane, propylene, n-butane, i-butane, i- 380 0.02026
butene, n-pentane, i-pentane, n-hexane, and n-heptane. 4
499 0.02264
Using Equation 2 to predict the pressure corresponding to 89
data points 5,6 it was found that the average absolute and Additional data are available.
8
maximum deviations for methane were 0.376% and +2.25%
respectively. Reference 6 discusses a generalization of the
Benedict-Webb-Rubin equation.
Thermal conductivity (liquid)

t°F K, Btu/hrft°F
2
Vapor pressure
-280 0.0841
.
.
Freezing point in air at 1 atm =-296 46 ∞ F (182 48 ∞ C) n.b.p. -258.68 0.0790
-200 0.0568
.
Boiling point at 29.921-in. Hg =-258 68 ∞F crit. temp -115.8 0.029 (reference )
10
∞ )
.
- ( 161 49 C
Values for liquid thermal conductivity represent estimates
9
by the authors using the method of Viswanath which seems
Vapor pressures are tabulated on p. 121 of Reference 2 from to be quite reliable for organic liquids (halogenated com-
10mm to 1,500mmHg and are represented by the Antoine pounds excepted).
equation.
(
+
log 10 P = A - B C t) (3) Thermal conductivity (vapor) 7
or: t°F K, Btu/hrft°F
-300 0.00541
(
t = B A - log 10 P) - C (3a) -200 0.00895
-100 0.01265
-40 0.0149
with P in mmHg and t in °C.
-20 0.0157
0 0.01645
A = 6.61184 20 0.01725
B = 389.93 40 0.01805
C = 266.00 60 0.0190