Special steel and platinised noble metal dialysis electrodes - resist periodic current reversals to clean membranes

摘要

In electrodialysis equipment formed of one or more cell sets each contg. a number of cells aligned in the liq. flow direction, at the outer face of the end cell in each set is one electrode (a or b) and at the outer faces of all intermediate cells are the same electrodes, where a acts as an anode and b as a cathode. Electrode a is pref. of platinised Ti, Nb or Ta, and electrode b is pref. a special steel, neither type being subject to attack when acting as anode/cathode respectively. The electrodes are pref. expanded metal, and sepd. by a perforated non-conductive spacer. The electrodes may be corrugated or have bulged surfaces. Used for desalification plant using cation and anion exchanger membranes in alternating sequence to form the individual dialysis cells. The cells are not damaged by periodic current reversal to remove membrane fouling deposits.