Development of a Laser Optical Sensor for Measuring Bubble Characteristics in an Oily Liquid Bath.

Oily liquids such as silicone oil and normal pentane have been commonly used as the model for top slag to investigate the role of the top slag on the mixing in the bath of various refining processes. An electroresistivity probe is a powerful tool for measuring bubble characteristics in a bath filled with a liquid of high electrical conductivity and it is extensively used in water model experiments. Unfortunately, the electrical conductivity of oily liquids is very low, and accordingly, the electroresistivity probe looses its validity in oily liquid baths. Considering these circumstances, a two-channel laser optical sensor was developed to measure the bubble characteristics in oily liquid baths. Gas holdup, mean bubble rising velocity and mean bubble chord length were measured accurately, whereas measurement of bubble frequency was disturbed by Doppler signals originating from the bubble surface.