Hydraulic classifier

Claim 1

APPARATUS FOR THE HYDRAULIC CLASSIFICATION TREATMENT OF A PULP CONTAINING A MIXTURE OF PARTICLE SIZES RANGING FROM FINE TO COARSE, TO EFFECT THE SEPARATION OF THE MIXTURE INTO A FRACTION OF FINES AND A FRACTION OF SANDS, DEFINED AS UNDERSIZE AND OVERSIZE PARTICLES RESPECTIVELY, WHICH APPARATUS COMPRISES A LONGITUDINAL CLASSIFYING POOL HAVING SAID MIXTURE SUPPLIED THERETO IN A PORTION THEREOF AND SAID FRACTION DISCHARGED FROM ANOTHER PORTION THEREOF, SAID POOL PROPER BEING CONFINED WITHIN A SPACE DEFINED BY A HORIZONTAL BOTTOM FACE A PAIR OF WIDE WALL FACES, AND A TRANSVERSE FACE AT EACH END ENDWISE DEFINING THE CLSSIFIER POOL, THERE BEING A HORIZONTAL BOTTOM WHICH PRESENTS SAID BOTTOM FACE TO THE POOL SUPPORTING STRUCTURE FOR PROVIDING HORIZONTAL BACK-AND-FORTH MOVEMENT OF SAID BOTTOM, A PAIR OF SIDE WALL PORTION UNITARY WITH SAID BOTTOM TO PROVIDE SAID SIDE WALL FACES, A STATIONARY WALL PORTION AT EACH END TO PROVIDE SAID END FACES OF THE CLASSIFYING POOL, AND SEALING MEANS EFFECTIVE WITH RESPECT TO EACH END WALL PORTION AND THE ASSOCIATED ENDS OF THE BOTTOM AND SIDE WALL PORTIONS FOR CONFINING THE PULP UNDERGOING CLASSIFICATION BETWEEN SAID STATIONARY END WALL PORTIONS, ACTUATING MEANS FOR IMPARTING HORIZONTAL MOTION TO SAID BOTTOM STRUCTURE SUCH AS WILL PRODUCE RELATIVE MOTION BETWEEN SAID BOTTOM AND OVERSIZE PARTICLES THEREON, CONTROLLABLE WATER SUPPLY CONDUIT AND DISTRIBUTING MEANS FOR EMITTING HYDRAULIC AUXILIARY WATER AT A CONTROLLED RATE DISTRIBUTIVELY IN A MANNER WHEREBY THE WATER IN EFFECT RISES IN SUBSTANTIALLY UNIFORM DISTRIBUTION FROM THE BOTTOM, AND WHEREBY IN TURN THERE ARE FORMED AND MAINTAINED IN SAID POOL HORIZONTAL CLASSIFICATION ZONES COMPRISING SUBSTANTIALLY A SANDS ZONE OF OVERSIZE PARTICLES AT THE BOTTOM, A FINES ZONE OF UNDERSIZE PARTICLE AT THE TOP, AND AN INTERMEDIATE ZONE CONTAINING A MIXTURE OF UNDERSIZE AND OVERSIZE PARTICLES IN TEETER CONDITION, THERE BEING PROVIDED AN OVERLOW WEIR FOR OVERFLOW DISCHARGE OF UNDERSIZE PARTICLES FROM SAID TOP ZONE OF THE POOL, AND AN UNDERFLOW DISCHARGE PASSAGE AT THE BOTTOM, AND ADJUSTABLE MEANS FOR CONTROLLING THE RATE OF UNDERFLOW DISCHARGE AND THUS FOR CONTROLLING THE CUT BETWEEN THE UNDERSIZE AND OVERSIZE, SO THAT BY THE CONCURRENT ACTION OF THE HORIZONTAL MOTION OF THE BOTTOM FACE AND OF THE RINSING FLOW OF THE HYDRAULIC WATER THERE ARE PRODUCIBLE OVERFLOW AND UNDERFLOW SIZE FRACTIONS EACH SUBSTANTIALLY FREE FROM STRAY PARTICLE SIZES OF THE OTHER.