PRESSURE DROP IN ELECTROCHEMICAL CELL WITH FIXED BED

Abstract

Experiments were performed to study hydrodynamic characteristics of three-phase system (Solid-Liquid-Gas) in a cylindrical cell, where a gas phase (hydrogen) was electrochemically generated. Two-phase fluid (gas-liquid), in which an electrolyte was a continuous one, flowed through the fixed bed, packed of glass particles (d=3 mm, d=2 mm, d=1.5 mm). What was examined was the influence that electrolyte velocity, current density and particles diameter had on the relative pressure drop (ΔP/ΔP0) through fixed bed. It was found that with velocity increase of electrolyte flow (w=0.00587-0.03 m/s), the relative pressure drop decreased through the fixed bed. At higher electrolyte velocity (0.03 m/s), fluidisation appeared, whereas at a little lower electrolyte velocity of 0.03 m/s, gas channels, which form through the bed, enable quicker gas flow and also a lesser pressure drop. With the current density increase, pressure drop increased, since greater gas quantities stayed behind in the fixed bed. Besides, it was also found, that relative pressure drop decreased with diameter decrease of glass particles, which formed the bed.