VOL. 12, NO. 12
INDUSTRIAL AND ENGINEERING CHEMISTRY
748
The Supersonic Oscillator
TABLE 11. DATAOF TYPICAL RUK Conditions of operation: total reaux, atmospheric pressure Mixture: carbon tetrachloride, b. p. 170.2’ F.: toluene, b. p. 231.1’ F. Heaters used: middle a n d lower Steam: 15 pounds per sq. inch gage: 21.48 pounds per hour Reflux rate: 182 pounds per hour Cooling water: in, 43’ F . ; out, 46’ F.; rate, 6630 pounds per hour Plate No. from T o p
1
2 3
4 5 6 7 8 9 10
Temperature, F. 171 172 173 175 178 183 192 200 212 220
Composition, Mole Fraction CClr Liquid Vapor 0.995 0.950 0.952 0.920 0.916 0.873 0 811 0.873 0.805 0 740 0.640 0,732 0 483 0 632 0 340 0 463 0.191 0 314 0 121 0 192
BERNARD H. PORTER Acheson Colloids Corporation, Newark, N. J.
Murphree Plate Efficiency.
%
161. 71.1
61.5 60.8
49.2 55.0 70 59 76 57
9 7 4
3
Boiler 226 ... ... Reflux a t orifice 56 o:i92 .., ... Reflux into column 169 0.992 . . ... Liquid return t o boiler (LO) .. 0 050 ... ... Over-all plate efficiency, 78% Heat balance: Given up by steam, 20,300 B. t . u. per hour Taken out by cooling water, 19,900 B. t. u. per hour Unaccounted for, 400 B. t. u. per hour, 1.97%
attempt was made during the run to maintain conditions any more carefully than is the practice with students. The heat balance is good, and the individual plate efficiencies are typical. These latter vary a little from plate to plate, and the particularly high efficiency of the top plate is not always obtained.
AS
EARLY as 1917 Langevin oscillated quartz crystals at their natural frequency with a Poulsen arc and pro-
duced intense sound waves of high frequency for submarine signaling. Since this initial effort the arc system has been replaced by the more stable vacuum tube oscillator, thereby extending the practical applications for supersonic energy. Some of the more important uses for waves 1%-hichvibrate with frequencies u p to 2,000,000 cycles per second (1.5 X cm. wave length) include the following. Supersonic waves Reduce the viscosity of such colloidal solutions as gelatin, agar-agar, and gum arabic Emulsify such immiscible liquids as benzene, oil, paraffin, and mercury with water Disperse both l o w and high-melting point metals in water, glycerol, and petroleum Aid in the manufacture of catalysts and sols for chemical and pharmaceutical industries
Acknowledgment The authors wish to acknowledge the assistance of Wallace Pritchard, departmental mechanic, in the construction of the still, and Albert Capuro, of the department, for the drawings.
Literature Cited 6’
Perry, J. H., Ed., “Chemical Engineers’ Handbook”, p. 1127, New York, McGraw-Hill Book Co., 1934. (2) Zimrnerman, 0. T., and Lavine, I., “Unit Operations Laboratory Equipment”, 2nd ed., pp. VI-9, XVI-3, University of North Dakota Press, 1940. (1)
OSC/LLATOR UNIT
f
Acetone-Ether Mixtures for Drying Glassware
-L
AARON E. MARKHAM University of Washington, Seattle, Wash.
M
I X T U R E S of acetone and ether have been found more satisfactory than pure acetone for drying glassware. A mixture containing equal parts of the two by volume has been used. The vapor pressure of this mixture a t 30” C. is about 90 per cent higher than that of pure acetone ( I ) , and evaporation is correspondingly faster. Thus bottles rinsed with the mixture and inverted, without the use of suction or air, dried in about two thirds the time required when pure acetone was used. The mixture has better solvent power than acetone for greases, especially the customary stopcock preparations. The formation of a second phase does not occur so long as the water content is low, for the mixture will tolerate 13 per cent b y volume of water.
Literature Cited (1) Sameshima, J. Am. Chem. SOC.,40, 1482 (1918).
LRECT/FlER UNIT
FIGURE 1. OSCILLATOR AND RECTIFIER Prevent grain formation and improve homogeneity and stability during the preparation of photographic emulsions Cleave such highly polymerized molecules as starch, gum arabic, and gelatin Liquefy such thixotropic gels as iron hydroxide, bentonite, and aluminum hydroxide Accelerate peptization (the rate of solution of rubber in aniline and ether, for example, is increased by this means. Supersonic irradiation also peptizes hydrated precipitates such as iron, chromium, and aluminum hydroxide, which cannot be reduced by other mechanical means) Disperse liquids like benzene, toluene, and water in air Coagulate aerosols Orient in liquids such anisodimensional particles as mica, glass, and quartz
