BEHAVIOR OF ELECTROGENERATED HYDROGEN AND OXYGEN BUBBLES IN NARROW-GAP CELLS .2. APPLICATION IN CHLORINE PRODUCTION

A comparison is made between H-2 and O2 evolution inside a thin channe l cell and Cl2 evolution inside an industrial membrane cell. Since the appearance of bridging bubbles is linked to the behaviour of free bub bles and that similar conditions of gas evolution exist (gas flow rate and free bubble escape behaviour), it is concluded that bridging bubb les are expected to form on the anode side inside industrial chlor/alk ali cells. This phenomenon may also occur on the cathode side of the c ell depending on the distance between the membrane and the electrode. Solutions to the problems caused by these particular bubbles are discu ssed which include correct selection of the electrode geometry, membra ne positioning and cell design.