I/EC Brief
I n d . E n g . C h e m . 5 1 , 8 9 - 9 2 (1959)
Possible only with
Correlating Heats of Solution and Vapor-liquid Equilibria. Construction of Ponction Diagrams Heats of solution of solids, liquids, and gases in liquids control heat balances in Ponchon diagrams and enthalpy charts of solutions of solids in liquids. H o w e v e r , few calorimetric data are available for usual construction and theoretical calculations. T h e logarithmic plot of partial pressures of a solvent out of a solution vs. a temperature scale derived from vapor pres sures of a reference substance gives straight lines whose slopes allow determination of heat of solution or of infinite dilution through a novel integration procedure. From these a precise plot of isotherms of integral heats of solution vs. liquid composition is developed. A simple, precise method is demonstrated for constructing a Ponchon diagram for distillation of the irregular system, chloroform-ethanol. D O N A L D F. O T H M E R , R O N A L D C . K O W A L S K I , a n d L E O N A R D M . NAPHTALI P o l y t e c h n i c I n s t i t u t e of B r o o k l y n , 333 J a y S t . , B r o o k l y n 1 , Ν . Υ .
I/EC Brief
I n d . E n g . C h e m . 5 1 , 9 3 - 4 (1959)
Isobaric Vapor-Liquid Equilibria T h e effect of changing temperature on the activity co efficient equations for isobaric vapor-liquid equilibrium sys tems has usually b e e n overlooked. A method to take this into account has b e e n developed. T h e Redlich and Kister equation of activity coefficients in binary solutions is modified for isobaric conditions, giving significant improvement of correlation for some systems. T h e modified equations are appropriate for correlation of isobaric vapor-liquid equilibria w h e n the system shows a wide boiling range and considerable heat of solution. K. C . C H A O D e p a r t m e n t of C h e m i c a l Wisconsin, Madison, Wis.
Engineering,
University
of
I/EC Brief
a
SIGMAMOTOR PUMP M o v e Corrosive Liquids Material being pumped never comes in contact w i t h pump mechanism. W a v e like motion of steel fingers forces m a t e r i a l through Tygon t u b i n g . By changing size of t u b i n g , capacity can be increased or decreased. Pump h o u s i n g o p e n s f o r removal a n d insertion o f tubing.
Pump 2 or 3 Different Liquids Simultaneously Some models w i l l accommo date up to four tubes so that four different liquids can be passed through the pump at one time w i t h o u t danger of c o n t a m i n a t i o n .
Feed a n d M i x One or more tubes can be feeding material to a mix w h i l e a larger tube is recir culating the l i q u i d t o pro duce a g i t a t i o n and thorough m i x i n g . Viscous materials c a n be p u m p e d w i t h o u t danger of g u m m i n g or p l u g g i n g . Remove t u b e a n d pump is clean.
Meter A d d i t i v e s I n d . E n g . C h e m . 5 1 , 9 5 - 1 0 2 (1959)
Activity Coefficients and Molecular Structure. Implications in Separations Activity coefficients of solutes at infinite dilution in sol vents fall into a pattern with respect to carbon numbers of solute and solvent which allows efficient amplification and application of relatively few experimental data to all varie ties of separation processes involving a liquid phase. G . J . P I E R O T T I , C . H . D E A L , a n d E. L. Shell Development Co., Emeryville, Calif.
DERR
One or more additives can be pumped to a solution in the exact amount desired by selecting the correct size of t u b i n g and r e g u l a t i n g pump speed. Various con trols can be incorporated to close valves ahead of p u m p . Capacities f r o m 0.5 cc. per m i n . t o 4.5 G.P.M.
Write for complete information on sizes and capacities.
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REFERENCE-
4 6 N. Main Street VOL. 5 1 . NO. 1
Middleport, Ν. Υ. ·
JANUARY 1959
17 A
