Experimental study of hydrodynamic and bubble size distributions in electroflotation process

摘要

The objective of this contribution is the experimental study of the hydrodynamic and the bubble size distributions in the electroflotation process.The influence of some operating conditions such as current density and physical properties of liquid phase on some hydrodynamic parameters and the bubble size distribution are discussed.The effects of the current density,viscosity and surface tension of the liquid phase on the gas hold up,the bubble rise velocity,the average bubble diameter and the bubble size distributions are experimentally investigated.Bubbles tend to become smaller with decreasing surface tension,current density and viscosity.Gas hold up tends to increase with increasing current density and decreasing viscosity.The bubble rise velocity exhibits the same behaviour as the gas hold up and so it increases with the increasing current density and decreases with increasing viscosity.Bubble size distribution depends only on the current density,and the wide range of bubble sizes increases with increasing current density.For such systems most of the hydrodynamic parameters depend on the current density and physical properties of the liquid phase.Experimental results are also fitted with empirical equations which relate gas hold up,bubble rise velocity,and average bubble diameter with the current density and viscosity of the medium.