Flexible belt filter unit

Claim 1

A VACUUM FILTERING UNIT COMPRISING A ROTARY FILTERING DRUM AND MEANS SUPPORTING SAME FOR ROTATION ABOUT A HORIZONTAL AXIS, SAID DRUM HAVING A GENERALLY CYLINDRICAL SURFACE FORMED WITH A PLURALITY O AXIALLY PARALLEL RELATIVELY UNIFORMLY SPACED TRACTION GROOVES OF INWARDLY TAPERING CROSS-SECTIONAL CONFIGURATION; A DISCHARGE ROLLER ROTATABLE ABOUT AN AXIS PARALLEL TO THE ROTATIONAL AXIS OF THE DRUM AND SPACED FROM THE DRUM; A FLEXIBLE ENDLESS POROUS FILTER BELT OPERATIVELY DISPOSED AROUND SAID DRUM AND SAID DSCHARGE ROLLER FOR MOVEMENT THROUGH AN ENDLESS CIRCUIT INCIDENT TO ROTATIONOF THE DRUM, SAID BELT HAVING FIXED ON ITS INNER SURFACE A PLURALITY OF RELATIVELY PARALLEL TRACTION RIBS OF INWARDLY TAPERING CROSS-SECTION CONFIGURATION CONFORMING GENERALLY TO SAID TRACTION GROOVES, SAID TRACTION RIBS EXTENDING TRANSVERSELY OF THE BELT AND POSITIONED FOR RECEPTION IN THE RESPECTIVE TRACTION GROOVES FOR IMPARTING A POSITIVE DRIVE TO THE BELT AND PREVENTING WRINKLING THEREOF; MEANS SUPPORTING SAID BELT AROUND THE DRUM WITH ITS INNER SURFACE SPACED FROM THE DRUM FOR RECEPTION OF THE EFFLUENT FROM THE FILTERED MATERIAL, CERTAIN OF THE SAID TRACTION RIBS BEING IMPERFORATE AND EXTENDING CONTINUOUSLY ACROSS THE DRUM TO FUNCTION AS SEALING STRIPS SUBDIVIDING SAID SPACE INTO RELATIVELY ISOLATED SECTORS; SUCTION MEANS COMMUNICATING WITH THE RESPECTIVE SECTORS BETWEEN ADJOINING SEALING STRIPS, SAID RIBS IN EACH SECTOR BETWEEN RELATIVELY ADJOINING SEALING STRIPS BEING FORMED TO PERMIT THE PASSAGE OF FLUID TO THE RESPECTIVE SUCTION PASSAGES, SAID BELT BEING FORMED OF ELASTIC MATERIAL AND HAVING A RESILIENTLY ELONGATED PORTION BOTH AROUND SAID DISCHARGE ROLL AND BETWEEN THE SAID ROLL AND THE DRUM, TO FACILITATE THE LOOSENING AND DISCHARGE OF THE FILTER CAKE FROM THE BELT AND ALSO TO DEFORM TEMPORARILY THE PORES OF THE BELT WHEREBY TO FACILITATE THE REMOVAL OF SOLIDS THEREFROM; THE MESHING RELATON BETWEEN SAID BELT TRACTION RIBS AND SAID DRUM TRACTION GROOVES TOGETHER WITH THEIR TAPERING CROSS-SECTIONAL CONFIGURATION FUNCTIONING TO CONTRACT SAID RESILIENTLY ELONGATED PORTION OF THE BELT INCIDENT TO ITS RETURN TO THE DRUM.