Wall to bed mass transfer in the presence of double cone promoter in a three phase fluidized bed with conical entry of electrolyte

Abstract

Investigations have been carried out experimentally to study the effect on wall-to-bed mass transfer coefficient in presence of double cone promoter in a three-phase fluidized bed with a conical entry of electrolyte.  The system chosen was an electrolyte as liquid phase, glass spheres of different diameters as solid phase and inert nitrogen as gas phase.  The electrolyte was an equimolar solution of potassium ferricyanide and potassium ferrocyanide each of 0.01N with 0.5N sodium hydroxide as indifferent electrolyte. The reaction considered was the reduction of ferricyanide ion. The experiment had been carried out at temperature range of 36 to 38oC at which the physical property values of the electrolyte were known from literature. The mass transfer coefficient was computed from the measured limiting current. It was found that the mass transfer coefficient was relatively independent of liquid velocity within the range covered in the present experiment.  The kL increased marginally with increasing gas velocity.  The kL was not influenced significantly by particle size and diameter of promoter within the present study range. The entire experimental data have been correlated in terms of Coulburn jD-factor and particle Reynolds number.