Activated carbon powder continuous regeneration - by resistance heating while descending a column contg. perforated electrodes, giving uniform heating

摘要

Particulate activated carbon is regenerated by allowing it to descend through a vertical column, in which electrodes are arranged horizontally and spaced apart; each electrode comprises a large number of through passages or holes and a number of communicating ducts between these holes on the underside of the electrode. Both ducts and holes are large enough for the carbon particles to pass freely through them. Alternatively, each electrode is composed of a grating with correspondingly large apertures. A voltage is applied across the electrodes, to generate a current through the activated carbon as it flows down and thus heat it. Pref. the passages are uniformly distributed over the electrodes; the activated carbon particles are spherical, and the holes constitute >=25% of the total electrode surface area. The process can be operated continuously, by regularly charging the top of the column with fresh carbon for treatment. The current density is fairly uniform so that uniform heating of the material is produced.