Measurement of Axial Dispersion Coefficient of the Continuous Phase in a Pulsed Disc and Doughnut Column Using Dispersion Model with Radiotracer Technique

Abstract

High efficiency and low required area for the pulsed columns are interesting and useful especially in nuclear industries in spite of exposure and radiation protection requirements. In this research, dispersion coefficient in a typical disc and doughnut pulsed column in a two phase system (water and kerosene) was determined via radiotracer technique. In the radiotracer method, two Geiger-Mueller detectors at the top and bottom of the active section of the pulsed column and 99mTc in the form of NaTcO4 as radiotracer are used. Dispersion is introduced by Pecletdimensionless number which is inversely propotional to the dispersion coefficient. The continuous and dispersed phase flow rate, amplitude and frequency of pulse as the effective parameters on axial mixing and dispersion coefficient magnitude have been studied. Experimental results indicate that by increasing the continuous phase flow rate, the dispersion coefficient decreases. Also, by increasing the dispersion phase flow rate as well as the amplitude and frequency of the pulse, the dispersion coefficient will increase.

Keywords

• pulsed disc and doughnut columns
• radiotracer
• axial dispersion