Product discharge means for hydraulic classifying apparatus

Claim 1

HYDRAULIC SIZING APPARATUS COMPRISING, IN COMBINATION, MEANS PROVIDING A TEETER COLUMN FOR RECEIVING DIVIDED SOLIDS TO BE CLASSIFIED ACCORDING TO SETTLING RATE, SAID MEANS INCLUDING MEANS INTRODUCING LIQUID TO PROVIDE UPWARD FLOW IN THE COLUMN FROM THE FOOT THEREOF AND SAID TEETER COLUMN MEANS BEING ADAPTED TO ACCUMULATE SOLIDS OF PREDETERMINED FASTER SETTLING CHARACTERISTICS NEAR THE FOOT THEREOF, SAID TEETER COLUMN MEANS COMPRISING A TANK FOR THE TEETER COLUMN, HAVING MEANS PROVIDING AN UPPER LEVEL FOR LIQUID IN THE TANK, SIPHON MEANS OPENING INTO SAID TEETER COLUMN MEANS NEAR THE FOOT THEREOF FOR WITHDRAWING A PULP OF ACCUMULATED SOLIDS, SAID SIPHON MEANS EXTENDING THROUGH AN UPPER REGION ABOVE THE AFORESAID UPPER LEVEL AND THENCE TO A LOWER REGION WHICH IS BELOW SAID UPPER LEVEL AND OUTSIDE THE TANK, SAID SIPHON MEANS COMPRISING A CONDUIT OPENING FOR DISCHARGE AT SAID LOWER REGION, AND SAID SIPHON MEANS INCLUDING AIR VENT MEANS THEREIN CONTROLLABLE TO MODIFY THE FLOW OF WITHDRAWN PULP THEREIN, A HYDROSTATIC COLUMN'' OPENING IN SAID TEETER COLUMN MEANS NEAR THE FOOT THEREOF AND EXTENDING TO AN UPPER LOCALITY ABOVE SAID UPPER REGION, FOR RISE OF LIQUID IN SAID COLUMN TO A LEVEL MEASURED BY THE PULP DENSITY IN THE TEETER, COLUMN, AND MEANS ASSOCIATED WITH THE HYDROSTATIC COLUMN AND CONTROLLED BY THE LIQUID LEVEL THEREIN AND COMPRISING A VALVE FOR CONTROLLING SAID SIPHON FLOW-MODIFYING MEANS, TO PREVENT WITHDRAWAL OF SOLIDS, IN SAID SIPHON MEANS, THAT DEPART FROM THE SAID PREDETERMINED SETTLING CHARACTERISTS.