Method for separating solids in liquid suspension

Claim 1

THE METHOD OF EFFECTING THE UNDERWATER SCREENING SEPARATION, INTO TWO FRACTIONS, OF A HETEROGENEOUS SUSPENSION OF TWO GROUPS OF PARTICLES, THE PARTICLES OF THE FIRST GROUP HAVING THEIR LONGEST DIMENSIONS SUBSTANTIALLY GREATER AND THEIR SMALLEST DIMENSIONS SUBSTANTIALLY SMALLER THAN ANY DIMENSIONS OF THE PARTICLES OF THE SECOND GROUP, WHICH COMPRISES FORMING AN AQUEOUS SUSPENSION SUPPLY OF THE MIXTURE OF PARTICLES, SUBMERGING IN THE SUSPENSION A PERFORATED SCREEN PLATE HAVING HOLES WHICH ARE UNIFORMLY SUBSTANTIALLY LARGER THAN ANY DIMENSIONS OF THE PARTICLES OF THE SECOND GROUP AND UNIFORMLY SUBSTANTIALLY SMALLER THAN THE SAID LONGEST DIMENSIONS OF THE PARTICLES OF THE FIRST GROUP, THE SCREEN PRESENTING A SUBSTANTIALLY PLANE SURFACE FROM ONE HOLE TO EACH OF THE HOLES NEXT ADJACENT THERETO, APPLYING THE PRESSURE OF A HYDROSTATIC HEAD TO THE SUSPENSION TO MOVE THE SUSPENSION TO THE HOLES WHILE SIMULTANEOUSLY RELATIVELY MOVING THE SUSPENSION AND THE SCREEN AT A SUBSTANTIALLY CONSTANT PREDETERMINED VELOCITY IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE SURFACE OF THE SCREEN TO PRODUCE A RESULTANT VELOCITY OF THE LIQUID PORTION OF THE SUSPENSION THROUGH THE HOLES AT A SUBSTANTIAL INCLINATION TO THE AXES OF THE HOLES, ENTRAINING A PORTION OF THE PARTICLES OF THE FIRST GROUP WITH THEIR LONGEST DIMENSIONS AT AN INCLINATION TO THE HOLES AS THEY ENTER THE HOLES BY FLOW OF THE LIQUID AT SAID RESULTANT VELOCITY, DEFLECTING THE SAID ENTRAINED PORTION OF THE PARTICLES OF THE FIRST GROUP AGAINST THE EDGES OF THE HOLES INTO A REJECTED FRACTION BY DIRECTING THEM AGAINST SAID EDGES BY THE FLOW OF WATER AT SAID RESULTANT VELOCITY, AND PASSING THE PARTICLES OF THE SECOND GROUP THROUGH THE HOLES INTO AN ACCEPTED FRACTION BY SAID WATER FLOW.

Claim 2

THE METHOD OF EFFECTING THE UNDERWATER SCREENING SEPARATION, INTO TWO FRACTIONS, OF A HETEROGENEOUS SUSPENSION OF TWO GROUPS OF PARTICLES, THE PARTICLES OF THE FIRST GROUP HAVING THEIR LONGEST DIMENSIONS SUBSTANTIALLY GREATER AND THEIR SMALLEST DIMENSIONS SUBSTANTIALLY SMALLER THAN ANY DIMENSIONS OF THE PARTICLES OF THE SECOND GROUP, WHICH COMPRISES FORMING AN AQUEOUS SUSPENSION SUPPLY OF THE MIXTURE OF PARTICLES, SUBMERGING IN THE SUSPENSION A PERFORATED SCREEN PLATE HAVING HOLES WHICH ARE UNIFORMLY SUBSTANTIALLY LARGER THAN ANY DIMENSIONS OF THE PARTICLES OF THE SECOND GROUP AND UNIFORMLY SUBSTANTIALLY SMALLER THAN THE SAID LONGEST DIMENSIONS OF THE PARTICLES OF THE FIRST GROUP, THE SCREEN PRESENTING A SUBSTANTIALLY PLANE SURFACE FROM ONE HOLE TO EACH OF THE HOLES NEXT ADJACENT THERETO, APPLYING THE PRESSURE OF A HYDROSTATIC HEAD TO THE SUSPENSION TO MOVE THE SUSPENSION TO THE HOLES WHILE SIMULTANEOUSLY RELATIVELY MOVING THE SUSPENSION AND THE SCREEN AT A SUBSTANTIALLY CONSTANT PREDETERMINED VELOCITY IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE SURFACE OF THE SCREEN TO PRODUCE A RESULTANT VELOCITY OF THE LIQUID PORTION OF THE SUSPENSION THROUGH THE HOLES AT A SUBSTANTIAL INCLINATION TO THE AXES OF THE HOLES, ENTRAINING A PORTION OF THE PARTICLES OF THE FIRST GROUP WITH THEIR LONGEST DIMENSIONS AT AN INCLINATION TO THE HOLES AS THEY ENTER THE HOLES BY FLOW OF THE LIQUID AT SAID RESULTANT VELOCITY, DEFLECTING THE SAID ENTRAINED PORTION OF THE PARTICLES OF THE FIRST GROUP AGAINST THE EDGES OF THE HOLES INTO A REJECTED FRACTION BY DIRECTING THEM AGAINST SAID EDGES BY THE FLOW OF WATER AT SAID RESULTANT VELOCITY, AND PASSING THE PARTICLES OF THE SECOND GROUP THROUGH THE HOLES INTO AN ACCEPTED FRACTION BY SAID WATER FLOW.