Effect of Gas Evolution on Current Density Distribution in Horizontal Electrolysis

The gas bubbles are evolved in the horizontal electroplating cell, so that the surface uniformity and other properties of electroplated steel sheet are affected by the current density distribution in the direction of net movement of gases. In the electroplating industry, it is essential to know and control the current density distribution. In this study, in order to clear the behavior of gas evolved in the horizontal electroplating cell, the effects of the liquid velocity and average current density on the current density distribution in the horizontal parallel electrolysis cell were experimentally investigated. Gas holdup in horizontal electrolysis cell increases in the direction of liquid flow, causing a corresponding variation in the ohmic resistance between electrode and electroplated steel sheet. The resulting non-uniformity in current density distribution and the increase in overall resistance in the horizontal electroplating cell are characterized by the modified equation of Tobias equation derived for vertical electrolysis cell. The experimental results of effect of gas evolution on current density distribution in the horizontal electrolysis cell were simulated by the model calculation modified by considering the gas holdup, which is effective for electrolysis evolving large amount of gas bubbles.