curacy of those experimental data selected for use. The data chosen for the “basic” properties were formulated in precise equations which were handled rigorously in order that all the accuracy of J the original experiments should be preserved in each of the derived properties. The p r i m a r y e q u a t i o n s comprised (1) an equation of state, (2) the heat capacity of the vapor, and (3) the heat capacity of the liquid. From these expressions, s e c o n d a r y equations were derived as required. New experimental determinations for none of these derived properties appeared necessary, but assurance on this point was not obtained until preliminary tables had been calculated and the results checked against accepted experimental values. H. G. TANNER, A. F. BENNIN‘G, In the preparation of the final tables, AND W. F. MATHEWSON arithmetical computations were carried out to 4s many significant figures as E. I. du Pont de Nemours & Company, Inc., Wilmington, Del. were justified by the precision of the equations, rather than by the absolute accuracy of the basic experimental data involved. This was done because, from the engineering viewpoint, precision and consistency of data are of major importance. HE properties of methyl chloride useful to refrigerating The great complexity of some of the equations made direct engineers have been investigated experimentally by arithmetical calculation of every tabular result prohibitive. numerous authors. Tables (7, 11, 13, 14, 17,24, 28) A “network” of calculated data was therefore constructed of these properties have been published from time to time, and intermediate points were interpolated by graphic and but are little more than assemblies of isolated quantities. algebraic methods. These methods were used with discreThe various sections of data lack thermodynamic consistency. tion in order that no significant sacrifice in precision should Furthermore, these tables no longer possess the qualities of result. accuracy, detail, and extensiveness sufficient to meet the To ensure arithmetical accuracy all preliminary calcularequirements of modern engineering. The present research tions were made in duplicate by persons who worked inwas undertaken to correct this situation. dependently. Prior to the preparation of the final table several preliminary tables were prepared in which all the Outline of the Procedure properties, in both saturated and superheat regions, were The science of refrigeration is concerned with the following calculated for temperatures differing approximately 20 ’ thermodynamic properties of a refrigerant: vapor pressure, between -60’ and 120’ C. The derived results were comheat and entropy of evaporation, specific volume and density pared with corresponding independent values found in the of the liquid as well as the saturated and superheated vapors, literature in order that any major error might be detected and total heat and entropy of the liquid and the saturated before the final detailed calculations were made. and superheated vapors. The abundant literature on methyl chloride was collected and critically examined for experiDevelopment of the Equations mental data which appeared suitable for the construction of a set of equations from which all the required quantities EQUATION OF STATE. The Onnes ( U ) equation of state could be computed. The review indicated that several of was selected to describe the behavior of the vapor. This the more important properties of methyl chloride are known equation has the advantage over many others which have to a high degree of accuracy. been proposed, in that i t can (with a slight modification of Instead of attempting to use as many of the available one or more of the virial coefficients, 99),reproduce smoothed data as possible, a novel approach was devised in which experimental data with very high fidelity over a large range equations expressing the experimental data for only three of conditions. The equation is an awkward one to manipulate properties of methyl chloride were used. These equations and when a large number of computations are involved formed the basis for a complete set of simultaneous equations economical considerations might favor a simpler equation of from which all the above-mentioned properties (except state. density and specific volume of the liquid) were calculated. The equation adopted is This procedure had the advantage of allowing calculated values for the vapor pressure and heat of evaporation to be PV = RT(l B’IV C’/Vz D’jV‘) (1) compared ultimately with published values not used in conwhere structing the equations. Furthermore, since all the calP = pressure in atmospheres culated data resulted from a set of simultaneous equations, V = molal volume, gram molecular volumes per mole consistency was a necessary consequence. Also, the reducR = gas constant = 1/273.1 tion of the number of primary equations to a minimum alT = absolute (Kelvin) temperature B’, C’, and D’ are the virial coefficients, defined as follows: lowed a more critical attitude to be taken toward the ac-
Thermodvnarnic Properties of Methyl Chloride
T
+
878
+
+
INDUSTRIAL AND ENGINEERING CHEMISTRY
JULY, 1939
879
chloride. They considered both the Raman and infrared spectra, and their choice of frequencies agreed substantially with those used by Vold. Since the spectral data for methyl chloride and the frequency analysis thereof appear to be well established, Vold's calculations were adopted without modification and formulated into the following equation : k T.
=
C+ = 2.13944
RT,/Pc = 0.02312015
+3.5775 1.84523 X 10-2 T + X lo-' TP - 8.33 X IO-'
T a (81 ..
critical temperature = 416.1O K P, critical pressure =, 65.9 atmospheres bl, b2, bs . . . db are the Onnes universal constants (16)
C;
The value used for the critical temperature was deduced by Centnerszwer (5) from a series of careful experiments. A more recent determination has been made by Harand (12). Using microtechnique, Harand reported the critical temperature to be 414.6" K. Although his micrometric method is probably capable of great precision, the result is of doubtful accuracy because of the difficulty of attaining physical equilibrium in a capillary tube. The preference given to Centnerszwer's value, 416.1" K., was influenced in part by Pickering (22) who suggested the weighted average value of 416.2" K. The critical pressure was found by Brinkman (3) to be 65.93 atmospheres. This value was confirmed by Baume (2) who reported 65.85. The intermediate value 65.9 was therefore used in this research. Pickering assigned 65.8 atmospheres as the value for this constant. Equations 2, 3, and 4 simplify to:
An approximate comparison of the results of the spectroscopic method for determining the heat capacity of methyl chloride, with those obtained by less accurate methods, is afforded by Table 11, where are listed the ratios of C P / C V calculated from the published data as indicated. Except. for the early data of Muller, these results are as consistent as could be expected.
= =
I
T
instantaneous "ideal" heat capacity of the vapor (calories per mole) at infinite volume = Kelvin temperature
=
OF METHYL CHLORID~ TABLE11. RATIOOF HEATCAPACITIES
Cp/Cv 1.266 1.279 1.199 1.30
-Condit,ionsO C. Pressure, mm. 10 0 16 560 (av.) 17 600 5 0
Author Vold ($7) Capstick ( 4 ) Miiller (BO)
Millar (18)
Method Spectroscopic Velocity of sound Velocity of sound Calorimetric
The heat capacity data published by Shorthose (24) have not been included in the comparison because Shorthose (5) merely estimated his reported values from the behavior of ethyl chloride. C' (6) HEATCAPACITY OF THE LIQUID. The heat capacity of D' = 60 Si/T &/T' &/T4 64/T6 (7) liquid methyl chloride is known over a small temperature range. Shorthose (24) made measurements under saturaThe coefficients in Equations 5, 6, and 7 are merely prodtion conditions between -30" and 30" C. Eucken and ucts of the Onnes universal constants and other constants Hauck (8) performed experiments between -83 O and -33 " C, defined above. They are conveniently grouped in Table I. A d o t of both sets of data showed the ~. curves to have slightly different slopes near the point of intersection (-30" C.). TABLEI. COEFFICIENTS FOR EQUATIONS 5, 6, AND 7 0 1 2 3 4 In spite of this disturbing discontinuity, 8 0.0027235 -2.1938 -6,9212 X 102 -5.0435 X 101 -3,7992 X 1011 the data Of Shorthose were for 7.2482 X IO" -3.0206 X 10-8 2.7389 2.5794 X 10' 1.4154 x 1010 use because his observations were made ? 1.8863 X 10-10 -2 3738 X 10-8 -6.7855 X 10-5 4.7833 -4.0140 X 106 a t temperatures nearer those required in the present study. His data are expressed by the equation The bracketed portion of Equation 5, and the coefficients Csat.iiq. = 12.60 2.2716 X lo-' T (9) listed in Table I, adapt the universal Onnes equation to CBat.liq.= heat capacity (calories per mole) for the methyl chloride, and cause the equation to describe in parliquid at saturation conditions ticular the data originally supplied by Kuenen (16) and subT = Kelvin temperature sequently adjusted to standard conditions by Holst (14). The calculated values for PV differed only *0.2 per cent Secondary Equations from the Kuenen-Holst data, even a t densities between 15 and ENTROPY OF VAPOR. The entropy of the vapor is obtain20 moles per gram molecular volume and a temperature of able from the equation: 400' K. which is only 19.1" below the critical. HEATCAPACITY OF THE VAPOR. The heat capacity of a vapor is a property which has long defied accurate measurement. Until recently the only methods available were But those based on calorimetric and velocity-of-sound data. These methods are still useful for gases of relatively complex composition, but they are inferior to the spectroscopic method where for those gases whose simple structure and composition enable characteristic frequencies to be ascertained from their infraCv = heat capacity of vapor at constant finite volume V red and Raman spectra. Vold (27) calculated the heat capacity of methyl chloride from the characteristic frequencies deduced from the infrared absorption spectrum. Voge and Rosenthal (26)subsequently presented a critical review of the published frequencies assigned to methyl B'
+ t%/T[2.765 + B2/Tz + Bs/T4 + P4/T6 + X 10-17(T0 - T)6.s - O.OOOOS] = Y O + y i / T + y z / T 2 + y s / T 4 + y4/T6 =,
Bo
+
+
+
+
+
VOL. 31, NO. 7
INDUSTRIAL AND ENGINEERING CHEMISTRY
880
The last term can be evaluated from the equation of state. Integration along an isotherm gives
c;
+
The free energy of the vapor is obtainable from the expression
This equation is abbreviated to C” =
Substituting the expressions for Hliq, and S1iq,in 19 yields B’lIq, = 12.60T - 12.60T In T - 1.1358 X 10-zT2 Soiiq, T Cl (21)
+I
Furthermore Since =
($)T
Equation 10 therefore becomes
V and
(g)
= -8
Equation 22 becomes dFvapOr= VdP
‘which upon integration from a fixed point VO’,Tot,arbitrarily chosen for convenience, to the desired point V,T along a path made up of an isotherm and an isometric, gives a result which may be written in the form: Svagor = 2.13944 In T 1.84523 X 10-2 T
+ + 1.7888 X 10-6 T2 - 2.777 X lo-’ T3 + 1.9869 X [In V + ( B e / V ) + 0.5Ce/V2 + 0.25De/V41
+ SO
v&por
(11)
in which = entropy
Be
=--=
dF,,por = d(PV)
dT
+
+
+
+
d(C’T) =--=
+ +
-
11
(12)
+ +
where Cz is an aggregate constant. Placing expression 21 for the free energy of the liquid equal to that for the vapor, 24, and also changing to common logarithms and multiplying certain terms by T J T , for subsequent convenience of calculation, the equation becomes
(so ~ i q . - SOvapor)
+
saturation conditions is expressed by the equation
T
+ So
liq.
(16)
may be obtained by subtracting Equation 16 from 11 and restricting use of the resulting equation to values of V at saturation. = Smt. vap.
S,,,.
=
- Xliq,
++
+ +
+
1.9869[1n V ( B e / V ) (0.5Ce/V2) ( 0 .25De/Ti4)] 0.004264 T 10.4606 In T 1,7888 X 1OMeT2 2.777 X 10-9T3 (SOvapor - SOliq,)
-
(17)
(18)
Specific Volume at Saturation Saturation conditions are those of equilibrium between liquid and vapor. The two phases are a t the same potential (Gibbs). I n short, Ai,. = F,,,,,. The free energy of the liquid, Fli,.. may be derived from the relationship Ais. = Hliq,
&.
- S1iq.T
has been described by Equation 16; and
in which C: is the integration constant.
-
+
+
Equation. 25 contains but two variables, T and V , and they are necessarily confined to saturation (equilibrium) conditions. For any given value of T , therefore, the corresponding value of V can be calculated.
ENTROPY OF EVAPORATION. The entropy of evaporation
Sevsp.
+
[(CI - Cd/Tcl/(T/Tc) 47,4745 24,0863 log (lOT/T,) - 2.132 X lOU3T5.9625 X lO-”TZ 6.9417 X lO-lUT3= 1,9869 [2.3026 log V - (2B/ V ) (1 . 5 C / V 2 ) (1.25D/V4)] (25)
ENTROPY OF LIQUID.The entropy of the liquid under
which becomes, from Equation 9, Sliq,= 12.60 In T + 2.2716 X
(23)
+ + +
+
+
-YO YZ T-2 3 ~ 3 T - ~574T-5 (13) dT De =--= d(D’T) - aO 62T-2 363T-4 564T-6 (14) dT SoYapor = integration constant plus arbitrary base
+
dT
- In V (ZB’/v) 4-(1 .5c’/v2) (1 .25D’/V4)] - [2.13944(T In T - T) 9.226X 10-3T2+ 5.962 X l O - V 3 6.94 X 10-’OT4 SOI & p 5 r TI CZ (24)
= 1.98692’[1
+
[(*)
- PdV - &apor
P and V are related by Equation 11has described .,S ,, the equation of state (Equation 1). If the integration of Equation 23 be performed in the manner used to obtain Equation 11 the result obtained is
of the vapor in (calories)/(rnole)(’K) -po p2T-2 3p3T-4
5PT4-’ -I- 0.00008 2.765 X lO-”(T, - T)6.3 T - T
Ce
or,
F,,,,,
X,,,,,
- S,,,,,dT
(19)
Saturation Pressure
If a value for the saturation volume a t a given temperature be known, the corresponding saturation pressure (vapor pressure) can be calculated by substituting these values of T and V in the equation of state (Equation 1). This circuitous procedure was used for calculating the saturation pressure a t temperatures about 20” F. apart. It would have been tedious to calculate the vapor pressure for every required temperature by this method. The results calculated for the 20” temperature intervals were therefore summarized by an empirical equation of the Kirchoff type, which was used for the calculation of the vapor pressures at the intermediate temperatures. The equation is loglo p
=
24.246131 - 3037.637/T~6.417250 loglo TR 1.5772 X 1 0 - 3 T ~ (26)
+
in which p
=
absolute saturation pressure in po2nds per square inch F. 459.6
TR = absolute Rankine temperature =
+
This equation can reproduce all the “20O-interval” calculated data between -40” and 160’ F. to within five units in the fourth place of the logarithm for p . A small correction curve was plotted, however, to give even closer agreement.
881
INDUSTRIAL AND ENGINEERING CHEMISTRY
JULY, 1939
Fales and Shapiro (9) have proposed a new type of equation, useful for expressing vapor pressures. Their equation was tried as an alternate for the Kirchoff equation. Using seven-place logarithms, the Fales-Shapiro equation yielded results equally as good as those from the Kirchoff equation. The latter was given preference, however, because one less logarithm was involved in performing the computations.
Heat Content of the Vapor The equation Fwpm = H v m m
- Smpm T
enables an expression for the heat content of the vapor to be derived. S,,,,, is known (Equation 11) ; also Fvapor(Equation 24). Substitution yields H,,,,,
=
+++ +
+ +
1.9869T[1 { (2B' B e ) / B ] f ((1.5C' 0.5Ce)/Bzj ((1.250' 0.25De)V4)] f 2.13944T 9.226 X 10-ST2 41.1925 X 1 0 - T 3 - 2.08 X 10-9T4 Cz (26) '
0 X
+
Heat Content of the Liquid
A
@
Equation 20 enables the heat content of the liquid to be calculated.
Latent Heat of Evaporation The latent heat of evaporation, He,,,,, was
- 80
calculated from the equation
- 40
HOLST SHORTHOSE REGNAULT VINCENT AND CHAPPUIS CALC'D., THIS RESEARCH
40
5
100
170
DEG R E E S FA H R ENHE IT (Scale, l/abs T.)
FIGURE 1 Hex.,,.
=
Swap.
T
(27)
SeVap., the entropy of evaporation, was expressed by Equation 18.
Evaluation of the Integration Constants Four integration constants, CI, CZ, S o l i q . , and So appear in the equations above and require evaluation. C1 and SolLq. were obtained directly from Equations 20 and 16, respectively, by making the customary assumption that a t -40" F. both heat content and entropy of liquid are zero. So rapor could be evaluated from Equations 27 and 18, following which Cz could be determined from Equation 25, provided the latent heat of evaporation and the corresponding saturated gas volume be known a t a given temperature. Published experimental data for the heat of evaporation of methyl chloride ( I , 6, 24,SO) were reviewed and reasonably good agreement was found. The value 102.45 calories per gram, a t -23.8" C., as determined by Shorthose, was selected for the present use. A value for the saturated specific volume was obtained * by way of vapor pressure data. Holst (14) had critically reviewed the vapor pressure measurements of six experimenters. He observed additional data and obtained results closer to those of Regnault (23) than to any of the others. Shorthose (2.4) subsequently confirmed the Holst and Regnault values. These various data were plotted for temperatures between -15" and -40" C. and the average curve showed that a t -23.8" C. the vapor pressure of methyl chloride was 0.9980 atmosphere. The corresponding satu- ' rated volume was computed from Equation 1 and found to be 0.8848 gram molecular volume per mole.
The substitutions were made as described and the equation constants were found to have the following values: Soliq. yapor
So
= -73.9841
C1
CZ
=
5.8014 -3554.200 3902.935
Liquid Density The density of the liquid could have been calculated by means of the Clausius-Clapeyron equation, but to have done so would have concentrated accumulated errors upon a quantity small in magnitude. Aside from equation testing, such calculations would have little practical value. Therefore, the tabulated densities and specific volumes of the liquid were obtained directly from published experimental data. Accurate measurements of the density of liquid methyl chloride have been made by several investigators (10, 19, Z4), and Holst (14) calculated the densities between -40" and 104' F. by the rule of rectilinear diameters. The various data were converted to cubic feet per pound (specific volume) and plotted against Fahrenheit temperature. The Holst data formed a smooth curve parallel to but slightly above the curve drawn through the data of Shorthose (24) and Morgan and Lowry. (19). The curve for data reported by the Gas Cylinders Research Committee (10) paralleled the Shorthose curve, but was below the latter and extended to higher temperatures. Relative to the Shorthose curve, the Holst data were high by 0.5 per cent, and the Cylinders Committee data were low by an equal amount. The Shorthose results were
INDUSTRIAL AND ENGINEERING CHEMISTRY
882
chosen as the most accurate because those of Holst were derived by indirect means, and the Cylinders Committee used samples taken directly from a storage tank, whereas Shorthose used freshly distilled material for his experiments. Shorthose made his measurements between -22 O and 86" F., whereas the Cylinders Committee data extended from 50" to 176" F. For use in this research, the Shorthose curve was extended to the higher temperatures by drawing it parallel to the Cylinders Committee curve. The Shorthose curve extrapolated in this manner probably describes accurately the specific volume of liquid methyl chloride over a wide range of temperatures. Tabular data for density and specific volume of the liquid were obtained from this curve.
Conclusions
'
Assuming no mistakes, the accuracy of the derived properties depends upon (1) the accuracy of the data entering the equations, and (2) the precision of the equations between the limits of the variables. If errors from these sources were absent a check on the accuracy of the calculated results would be superfluous. However, the possibility of errors from these sources was not absent and therefore a check on the accuracy of the results was desirable. To this end the calculated data for the heat of evaporation and vapor pressure were compared with independent experimental results. Heat of evaporation is a property which is difficult to measure directly with high accuracy. Most of the published values descend from calculations relating other properties which are more easily measured experimentally. The scarcity of direct experimental results for methyl chloride and the errors inherent in these measurements discount the value of the data as a reference useful for gaging the accuracy of the present work. However, the available data from the literature, along with corresponding values calculated by the procedures described above, are presented for comparison in Table 111.
VOL. 31, NO. 7
These results are probably as consistent as may be reasonably expected. I n contrast with heat of evaporation, vapor pressure measurements are accurately and readily made. Since an abundance of published data exists, the vapor pressure of methyl chloride over a wide temperature range is well established. Many of these experimental values were plotted and a smooth curve was drawn to the best fit. Except for a few apparently wild points, none of the experimental values deviated from the curve more than 1.5 per cent. Between -40" and 160" F. the data computed in this research followed the average curve within 0.5 per cent. In Figure 1 there are plotted published experimental data (14, 23-26) and the results calculated in this research. The curve, drawn through the calculated points, facilitates the comparison of the experimental with the calculated data. The agreement is surprisingly good throughout the entire temperature range. This excellence of agreement indicates not only that the calculated vapor pressures are probably accurate to within a fractional per cent of the true values, but also that the other equations used have likewise described methyl chloride properties with correspondingly high accuracy. Tables IV and V have been abbreviated to conserve space. Detailed tables may be obtained from the Chlorine Products Division, R. & H. Chemicals Department, E. I. du Pont de Nemours & Company, Inc., Wilmington, Del.
Aclmowledgment The authors gladly express their thanks to E. W. McGovern of the R. & H. Chemicals Department, E. I. du Pont de Nemours & Company, Inc., who initiated this project, and whose advice throughout was most helpful. They are also grateful to T. B. Drew and H. C. Carlson of the Engineering Department for simplifying the formulation of the equations for entropy and free energy of the vapor.
Literature Cited TABLE 111. HEATOF VAPORIZATION Temp.
F. 32 51.4 68.0
Calcd. (This Research) Observed B . t. u. per pound 174.08 174.4 168.92 167.95 164.39 171.3
Author Chappuis ( 8 ) Awbery and G r i 5 t h s (1) Yates (80)
TABLEIV. Temp., e
F.
Pressure Abs., Gage Ib./sq. in. Ib./sp. in.
Li uid ou. %./I&.
Volume Vapor ou. ft./fb.
(1) Awbery and Griffiths, Proc. Phys. SOC.(London), 44,121 (1932). (2) Baume, G., J. chim. phys., 6 , 1 (1908). (3) Brinkman, dissertations, Amsterdam, 1904. (4) Capstick, Phil. Trans. Roy. SOC.(London), A185, 1 (1894). ( 5 ) Centnerszwer, 2.qhysik. Chem., 49, 199 (1904). (6) Chappuis, Ann. chim. phys., [B] 13,498 (1888).
PROPERTIES OF SATURATED VAPOR" Density Liquid Vapor lb./cu.fb. lb./cu. it.
64.39 0.07861 0.01553 12.72 6.878 15.92b 63.78 0.1013 0.01568 9.873 11.52b 9.036 0.01583 7.761 63.17 0.1289 11.71 6.09Ob -10 14.96 0.266 0.01598 6.176 62.58 0.1619 62.00 0.2013 0.01613 4.969 0 18.90 4.201 61.65 0.2237 4.471 6.455 0.01622 5 21.15 61.31 0.2477 0.01631 4.038 10 23.60 8.903 60.72 0.3019 0,01647 3.312 20 29.16 14.46 35.68 20.98 0.01665 2.739 60.06 0.3650 30 40 43.25 28.56 0.016S4 2.286 59.38 0.4375 50 51.99 37.29 0.01704 1.920 58.69 0.5208 62.00 47.30 0.01724 1.624 58.00 0.6158 60 70 73.41 58.71 0.01744 1.382 57.34 0.7234 56.69 0.8451 0 01764 1.183 so 86.26 71.56 56.24 0.9253 0.01778 1.081 86 94.70 80.00 55.99 0.9819 0.01786 1.018 85.95 90 100.6 55.31 1.135 100 116.7 102.0 0.0180s 1.8814 54.55 1.303 110 134.5 119.8 0.01833 1.7672 53.79 1.490 120 154.2 139.5 0.01859 1.6710 52.99 1.698 0.01887 1.5889 161.1 130 175.9 52.22 1.927 140 199.6 184.9 0.01915 1.5189 51.41 2.181 150 225.4 0.91945 1.4586 210.7 50.56 . 2.457 160 253.5 238.8 0.01978 1.4070 170 283.9 269.2 0.02015 1.3613 49.63 2.768 b Inohes of mercury below one Copyright, 1939, E. I. du Pont de Nemours & Co., Inc. -40 -30 -20
~~
Entropy from -40° Liquid Vapor B. i.u./ib., B. t. u./ib. F. O F.
Heat Content from -40' Liquid Latent Vapor, B. t. u./ib. B. t. u./ib. B. t. u./lb. 0.000 3.562 7.146 10.75 14.39 16.21 18.04 21.73 25.44 29.17 32.93 36.71 40.52 44.36 46.67 48.21 52.09 56.00 59.93 63.89 67.87 71.87 75.90 79.97 atmosphere.
190.66 188.52 156.34 184.11 181.85 180.70 179.53
177.11
174.59 172.00 169.35 166.62 163.82 160.91 159.13 157.92 154.85 151.70 148.46 145.13 141.71 138.23 134.66 130.96
190.66 192.08 193.49 194.87 196.23 196.92 197.58 198.84 200.03 201.17 202.28 203.33 204.34 205.27 205.80 206.13 206.94 207.70 208.39 209.02 209.58 210.10 210.56 210.93
,
0.0000 0.0084 0.0166 0.0247 0.0327 0.0367 0.0406 0.0484 0.0560 0.0636 0.0710 0.0784 0 .OS56 0.0928 0.0970 0.0998 0.1069 0.1138 0.1206 0.1274 0.1341 0.1407 0.1473 0.1538
0.4544 0.4472 0.4405 0.4343 0.4284 0.4257 0.4229 0.4177 0.4126 0.4079 0.4034 0.3991 0.3950 0.3910 0.3887 0.3872 0.3836 0.8801 0.3768 0.3736 0.3705 0.3674 0.3646 0.3618
INDUSTRIAL AND ENGINEERING CHEMISTRY
JULY, 1939
883
TABLEV. PROPERTIES OF SUPERHEATED VAPOR"
v
H S Absolute pressure, 6 lb. per sq. in.. gage pressure, 17.7 in. vacuum Temp., O F., t (Satn. temp., -44.8'' F.) (0.4580) (14.45) (189.96) (At satn.) 0.4599 14,62 190.77 -40 0.4640 14.99 192.52 -30 0.4681 15.36 194.27 -20 0.4721 15.72 196.06 - 10 0.4760 16.09 197.84 0 0.4799 16.45 199.66 10 0.4838 16.82 201.48 20 0.4876 17.18 203.34 30 0.4914 17.55 205.19 40 0.4952 17.91 207.10 50 0.4989 18.27 209.01 60 0.5025 18.63 210.95 70 0.5061 18.99 212.88 80 0.5097 19.35 214.85 90 0.5133 19.71 216.82 100 0.5169 20.07 218.83 110 0.5204 20 42 220.84 120 0.5239 20.78 222.89 130 0.5274 21.14 224.94 140 0.5308 21.50 227.03 150 0.5342 21.86 229.11 160 0.5376 22.21 231.24 170 0.5410 22.57 233.36 180 0.5443 22.93 235.52 190 0.5476 23.29 237.69 200 0.5510 23.64 239.89 210 0.5542 24.00 242.09 220 0.5575 24.35 244.34 230 0.5607 24.71 246.60 240 0.5640 25.06 248.88 250 0.5672 25.42 251.15 260 I
(At satn.) -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 a
Absolute pressure, 10 Ib. per sq. in., gage pressure, 9.6 in. vacuum (Satn. temp., -26.1'' F.) (0.4446) (192.64) (8.993) 0.4471 193.67 9.124 0.4512 195.50 9.346 0.4552 197.32 9.567 0.4591 199.18 9.788 0,4630 201.04 10.01 0.4669 202.91 10.23 0.4707 204.78 10.45 0.4745 206.70 10.67 0.4782 208,62 10.89 0,4819 210.58 11.11 0.4856 212.53 11.33 0.4892 214.51 11.55 0.4928 216.50 11.77 0.4964 218.52 11.99 0,5000 220.54 12.21 0.5035 222.61 12.43 0.5069 224.67 12.65 0.5104 226.77 12,86 0.5138 228.86 13.08 0.5172 231 .OO 13.30 0.5206 233.13 13,52 0.5240 235.30 13.74 0.5273 237.47 13.95 0.5306 239.68 14.17 0.5339 241.89 14.38 0.5372 244.15 14.60 0.5405 246.42 14.81 0.5437 248.70 15.03 0.5469 250.98 15.24 0.5501 253.32 15.46 0.5532 255.66 15.67
V H 5 V H S Absolute pressure, 100 lb. per 8 9 : in., Absolute pressure, 20 lb. per sq. in., gage pressure, 85.3 lb. ger sq. in. Temp., ' F. Temp., O F. gage pressure, 5.3 lb. per sq. in. (Satn. temp., 89.6 F.) t (Satn. temp., 2.5' F.) t (206.11) (0.3872) (At satn.) (1.025) (196.58) (0.4270) (At satn.) (4.710) 206.21 0.3877 1.026 90 197.95 0.4300 10 4.801 0.3920 1.055 208.58 100 199.90 0.4341 4.917 20 0.3962 1.083 210.96 110 201.82 0.4380 5.032 30 0.4003 213.33 1.111 120 203.75 0.4420 40 6.146 0,4044 1.138 215.74 130 205.71 0.4458 5,260 50 0.4084 1.165 218.15 140 207.66 0.4496 60 5.373 0.4124 1.191 220.55 150 209.66 0.4534 70 5.486 0.4163 1.217 222.94 160 211.65 0.4572 80 5.599 0.4201 1.243 225.33 170 213.67 0.4608 90 5.711 0.4239 1.268 227.71 180 216.69 0.4645 100 5.823 0.4276 1.293 230.10 190 217.75 0.4681 5.935 110 0,4312 1.318 232.50 200 219.80 0.4717 6.046 120 0,4349 234.91 210 1.343 221.90 0.4753 6.157 130 0.4384 1.367 237.32 220 223.99 0.4788 140 6.268 0,4420 1.391 239.76 230 226.12 0.4823 150 6.379 0.4455 1.415 242.20 240 228.24 0.4858 160 6.489 0.4489 244.63 1.439 250 230.40 0.4892 6.599 170 0,4523 1.463 247.06 260 232.56 0.4927 6.709 180 0.4557 1.487 249.51 270 234.75 0.4961 6.819 190 0.4591 1.511 251.96 280 236.94 0.4994 200 6.929 0.4624 1,534 254.44 290 239.17 0.5028 210 7.038 0.4657 256.92 1.557 300 241.40 0.5061 220 7.147 0.4689 1.580 259.43 310 243.68 0.5094 230 7.250 0.4722 1.603 261.93 320 245.96 0.5127 240 7.365 0.4754 1.626 264.45 330 248.26 0.5159 250 7.474 0.4786 1.649 266.97 340 250.55 0.5192 260 7.583 0.4817 1.672 269.52 350 252.89 0.5224 7.692 270 0.4849 1.695 272.07 360 255.23 0.5256 7.801 280 0.4880 1.717 274.66 370 257.60 0.5287 290 7.910 0.4911 1.739 277.25 380 259.90 0.5319 300 8.019 0.4942 279.87 390 1.761 262.36 0.5350 310 8.128
.
(At sntn.) m 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350
Absolute pressure, 50 lb. per sq.. in., gage pressure, 35.3 lb. Der sq. in. (Satn. temp., 47.8' F.) (0,4043) (202.09) (1.992) 0,4053 2.003 202.55 0.4094 204.65 2.054 0.4134 200.77 2.104 0.4174 208.89 2.154 0,4213 211.03 2.203 0.4252 213.18 2.252 0.4290 215.35 2.300 0,4328 217.52 2,348 0.4366 219.70 2.396 0.4402 221.88 2,443 0.4439 224.10 2,490 0.4475 226.32 2.537 0.4511 228.55 2.584 0,4546 230.79 2.630 0.4581 233.05 2.676 0.4616 235.32 2,722 0.4650 2.768 237.61 0.4684 239.90 2.813 0.4718 242.24 2.858 0.4782 244.58 2.903 0.4788 246.92 2.948 0.4818 249.27 2.993 0.4851 251.65 3.038 0.4884 254.02 3.083 0.4916 256.43 3.128 0,4948 258.83 3.173 0.4980 261.27 3.217 0.5011 3.261 263.71 0.5043 266.18 3.305 0.5074 268.65 3.349 0.5105 271.17 3.393
160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440
Absolute pressure, 200 Ib. per sq. in., gage pressure, 185.3 Ib. per sq. in. (Satn. temp., 140.3' F.) (0.3702) (0.517) (209.60) 212.41 0.3749 0.533 0.3796 215.30 0.551 0.3842 0.506 218.09 0.3886 0.582 220.87 0.3929 0.597 223.61 0.3971 0.612 226.35 0.4012 229.05 0.626 0.4052 231.75 0.641 0.4091 234.43 0.654 0.4129 237.12 0.668 0.4167 0.682 239.75 0.4204 242.39 0.695 0.4240 245.02 0.708 0.4276 247.65 0.721 0.4311 0.734 250.29 0.4346 0.747 252.93 0.4380 0.760 255.58 0.4414 0.772 258.21 0.4448 0.785 260.86 0.4481 0.797 263.51 0.4515 206.17 0.810 0.4547 268.84 0.822 0.4580 271.51 0.834 0.4612 274.19 0.847 0.4644 0.859 276.88 0.4676 279.59 0.870 0.4707 0.883 282.31 0,4738 285.05 0.895 0.4769 287.79 0.906 0,4800 290.52 0,918
Copyright, 1939,E. I. du Pont de Nemours & Co., Inc.
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(22) Pickering, Natl. Bur. Standards, Sci. Paper 541 (1926). (23) Regnault. H. V., Inst. France, Paris Acad. Sci. Mdm., 26, 594 (1862). (24) Shorthose, D. N., Dept. Soi. Ind. Research (London), Special R e p t . 1 9 (1924). (25) Vincent, C . , and Chappuis, J., Compt. rend., 100, 1216 (1885). (26) Voge and Rosenthal, J. Chem. Phys., 4 , 137 (1936). (27) Vold, R . D., J . Am. Chem. SOC.,57, 1192 (1935). (28) Wagner, O., 2. ges. Kdlte-Ind., 34, 62 (1927). (29) Wohl, Kurt, 2. physik. Chem., 133, 305-349 (1928). (30) Yates, Phil. Mag., 171 2, 817 (1926). THISpaper is an outgrowth of work originated by W. F. Mathewson, East Weymouth, Mass., and carried out under a grant from the R. & H. Chemicals Department, E. I. du Pont de Nemours & Company, Inc.
