Hydraulic classifier

Claim 1

APPARATUS FOR THE HYDRAULIC CLASSIFICATION TREATMENT OF PULP CONTAINING A MIXTURE OF PARTICLES SIZES RANGING FROM FINE TO COARSE, TO EFFECT THE SEPARATION OF THE MIXTURE INTO A FRACTION OF FINES AND A FRACTION OF COARSE SIZE MATERIAL, DEFINED AS UNDERSIZE AND AS OVERSIZE PARTICES RESPECTIVELY, WHICH APPARATUS COMPRISES A TANK STRUCTURE FOR CONTAINING A CLASSIFYING POOL HAVING OVERFLOW MEANS FOR A FINES FRACTION AND HAVING SAID MIXTURE SUPPLIED THERETO IN ONE PORTION THEREOF AND SAID FRACTIONS DISCHARGED FROM OTHER PORTIONS THEREOF, SAID TANK STRUCTURE COMPRISING AN INTERNAL WALL STRUCTURE DEFINING THE SPACE OF SAID POOL PROPER AND HAVING STATIONARY RISING WALLS PROVIDING OVERFLOW DISCHARGE MEANS FOR THE FINES FRACTION AND PRESENTING FREE HORIZONTAL BOTTOM EDGES, AND FURTHER COMPRISING A HORIZONTAL RECIPROCATORY BOTTOM MEMBER SPACED DOWNWARDLY FROM THE FREE BOTTOM EDGES OF SAID RISING WALLS TO PROVIDE A PASSAGE FOR SAID COARSE FRACTION, SAID TANK STRUCTURE FURTHER COMPRISING AN EXTERNAL WALL STRUCTURE SURROUNDING SAID INTERNAL WALL STRUCTURE AND HAVING A SOLID BOTTOM TO PROVIDE A SANDS RECEIVING POCKETS SPACED DOWNWARDLY FROM SAID RECIPROCATORY BOTTOM MEMBER, TOP COVER MEANS RIGIDLY INTERCONNECTING SAID EXTERNAL AND INTERNAL WALL STRUCTURE, GUIDE MEANS FOR OPERATIVELY SUPPORTING SAID RECIPROCATORY BOTTOM MEMBER TO PERFORM HORIZONTAL RECIPROCATORY MOVEMENTS, AN UPSTANDING SANDS DISCHARGE WEIR PROVIDED EDGESWISE UPON SAID AUXILIARY BOTTOM MEMBER AND SPACED OUTWARDLY FROM SAID PASSAGE IN ORDER THAT COARSE FRACTION MATERIAL MIGRATING FROM SAID POOL THROUGH SAID PASSAGE MAY SPILL ACROSS SAID WEIR INTO SAID SANDS RECEIVING POCKET, SAID OUTER AND SAID INNER WALL STRUCTURES TOGETHER WITH SAID