摘要 |
<p>An electrically conducting filter medium (20) is cleaned in situ by applying, at intervals, a brief voltage pulse between the medium (20) and a counter electrode (18) so the process liquid undergoes electrolysis. The cleaning process is significantly improved by occasionally applying a voltage of reverse polarity. For example a 5 second cleaning pulse making the filter medium (20) cathodic might be applied every quarter of an hour, and a reverse polarity pulse of similar duration applied every two hours. This process can significantly increase permeation rates. <IMAGE></p> |