Rotary disc filtration process having means to prevent settlement of solids

A process for filtering a solid-liquid mixture, comprising the steps of:

• providing a filtration device containing a solid-liquid mixture, said filtration device having sidewalls defining a filter trough, a rotating filter disc having filter surfaces spaced from and substantially parallel to said sidewalls, and a feed device positioned at a surface of said mixture, said feed device having a feed pipe with an elongated opening extending parallel to said surface of the mixture, and a pair of guiding plates adjacent said opening in said pipe and extending parallel to and spaced from said filter surface, and spaced from said sidewalls of said trough,
• feeding a solid-liquid mixture through said feed pipe and downwardly between said guiding plates into said mixture contained in the trough and producing a first downward flow stream in the mixture in the trough and in a direction substantially parallel to the filter surfaces,
• producing a second upward flow stream in the mixture and directing the second flow stream against the first flow stream and substantially parallel to the filter surface to resist settlement of solids in the trough, and
• rotating said filter disc whereby said filter surfaces rotate substantially parallel to said first and second flow steams to filter said mixture.