Date of Award

Spring 1972

Document Type

Thesis

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering and Chemistry

First Advisor

Angelo J. Perna

Second Advisor

Howard S. Kimmel

Third Advisor

Richard B. Trattner

Abstract

The object of this research was to investigate the possibility of using externally supplied ultrasonic vibration to surface of a packed distillation column operating at total reflux to improve the separation. The apparatus used for this experimentation consisted of a 2 inch ID Pyrex column having three pairs of ultrasonic transducers epoxied equidistance along the external surface of the column. Each pair of transducers was driven separately by a 50 watt amplifier! power supply and a sine/square wave generator.

There were three types of binary mixtures covered during experimentation: minimum boiling azeotropes, maximum boiling azeotropes and full range mixtures. In all cases the use of ultrasonic vibrations increased the composition of the overhead when compared with the normal operation. The principles which govern this improvement in separation are not well defined but can be partially explained by a combination of the following:

  1. The velocity of the vapor and its direction are affected by the generation of high frequency sound waves and shock waves caused by caviation of the liquid.
  2. The liquid loading as well as the path of the descending liquid are modified by the cavfation of the liquid.
  3. The arrangement of the packing is altered during ultrasonic operation which is evidenced by the presence of broken berl saddles in the areas of the transducers.

The above mentioned conditions are probably only a few of the many phenomena which occur in this quasi-steady state process. Only further experimentation can answer the questions which this experimentation has uncovered.

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