0
.
VOl. 3, No. 2
ANALYTICAL EDITION
144
f 6 8 lo I2 RATE OF FLOM- CC./SEC.
2
Figure 3-Determination
I4
with 5.1 Per Cent COPin Inlet Gas
low. Bottle 7 (Schott and Gen. pattern 101) gave results only slightly inferior to those obtained with the bottle of the spiral type. The poorest results were obtained with the bottles of the Muencke and the Habermann types, the Muencke bottle being only slightly more: efficient than the Habermann bottles. Somewhat similar results were obtained in the experiments made with the inlet gas that contained only 5.1 per cent of carbon dioxide. Decreasing the concentration of the absorbable component in the original mixture has comparatively little effect in increasing the maximum rate at which the gas can be passed through any particular bottle without allowing a detectable amount of carbon dioxide to pass through unabsorbed. A comparison of curves 1 and 8 in Figure 3 shows that the efficiency of the commonly used Muencke bottle can be increased to a considerable extent by filling the space between the inlet tube and the wall of the bottle with glass beads. From the results shown in Figure 4 it is apparent that
0
I 8
4
I
I
I f2
/6
RATE OF fL.OW-CC/SEC Figure 4-Com
arison of Pressure Drop in $arious Bottles
the drop in pressure is considerably greater in those bottles that are provided with a distributing plate of sintered glass. This is to be expected, since in bottles of this type pressure is required not only to overcome the static head of the Iiquid, but also to force the gas through the small pores of the distributing plate.
Alignment Chart for Estimating Viscosity-Gravity Constant of Petroleum Lubricating Oils' W. F. Houghton and J. A. Robb THE ATLANTIC REFININQCOMPANY, PHILADELPHIA, PA.
T H E viscosity-gravity constant as developed by Hill and Coats ( I ) has been found to be a great aid in defining and classifying lubricating oils. It affords a convenient means for following the progress of various refining processes such as acid treatment and solvent extraction. From tests on the heavier fractions of crude oils, it gives an excellent clue to the properties of all the fractions. Table I gives the viscosity-gravity constants of lubricating cuts from various crude oils and shows the value of this index as a means of classification and identification. Constants of Lubricating Cuts from Table I-Viscosity-Gravity Various Crude Oils Reagan County Tex. 0.839 0.918 Sour Lake, Tex. 0,829 Salt Creek, Wy& 0.894 Heavy Mexican Burbank. Okla. 0.828 0.885 Sunset Calif. 0.827 Ranger, +ex. Spindl&op, Tex. 0.876 0.804 Eureka, Pa. Light Mexican 0.860 0.800 Buckeye, Ohio. Van Zandt County, Tex. 0.852 0.800 Milltown, Pa. 0.844 Seminole, Okla. ~~~
The viscosity-gravity constant is based on a relation between Saybolt viscosity and specific gravity as follows:
G
+ 1.0752 - A
log(V-338) -_ where A = viscosity-gravity constant G = specific gravity at 60' F. (1.5.6" C.) V = Savbolt viscosity at 100' F. (37.8' C.) 1
=A
Received November 7 , 1930.
When the viscosity is measured at 210' F. (98.9' C.), the following equation is used: G = 0.24 0.7558 0.022 log (V' - 35.5) where V' = Saybolt viscosity at 210' F. (98.9' G.) These equations are rather cumbersome and make the calculation of the constant so tedious as to detract from its general usefulness. To eliminate this factor, an alignment chart has been constructed which permits the rapid estimation of the constant from the viscosity and gravity data. I n this chart the left side is to be used for viscosities a t 210" F. (98.9' C.) and the right side for viscosities a t 100' F. (37.8' C,). I n using the chart for the evaluation of A , connect by means of a straight edge the proper mark on the viscosity scale with the corresponding value on the gravity scale. Then the value of A is given by the intersection of this line with the viscosity-gravity constant scale. For example, a Winkler distillate has a viscosity of 92 Saybolt seconds a t 210' F. (98.9' C.) and a gravity of 18.6' A. P. I. The constant is found to be 0.880. Another distillate has a viscosity of 350 Saybolt seconds a t 100" F. (37.8" C.) and a gravity of 28.4' A. P. I. The constant in this case is 0.822. This distillate falls in the class of highly paraffinic mixed-base lubricating crudes such as Williamson County, Texas.
+
+
Literature Cited (1) Hill and Coats, IND.ENG.CHEM., 20, 641 (1928).
April 15, 1931
INDUXTRIAL A N D ENGINEERING CHEMISTRY
SAYBOLT
V/SCOs/TY
AT
2/OoE
145
