Patent ID: 7011741

Claim:
In a pressure filter apparatus for separating a quantity of slurry into slurry solids and slurry filtrate liquids comprising in combination at least one filtration chamber comprising a pair of plates separatable from each other to close and open said chamber, a porous filter medium within said filtration chamber, said plates when closed forming a pressurizeable sealed filtration chamber with said porous filter medium between said plates, and input means in one plate and exit means in the other plate for slurry filtrate from said sealed filtration chamber while slurry solids are collected on said filter medium, a source of slurry at a slurry-input pressure coupled with said at least one closed filtration chamber, means for introducing said slurry into said sealed filtration chamber at said input means, a source of fluid at an elevated pressure higher than said slurry input pressure coupled with said at least one closed filtration chamber, means for introducing said fluid at elevated pressure into said sealed filtration chamber at said input means, said fluid at said elevated pressure having a limited capacity of fluid at elevated pressure, a source of fluid at a conventional pressure lower than said elevated pressure with said at least one closed filtration chamber, means for introducing said fluid at conventional pressure into said sealed filtration chamber at said input means, said source of fluid at said conventional pressure having a substantially unlimited capacity, and means for controlling said means for introducing said slurry, said elevated pressure fluid and said conventional pressure fluid to introduce said slurry and said fluids in controllable sequences and durations with said slurry introduced first, followed by said elevated pressure fluid for a first duration and followed by said conventional pressure fluid for a duration substantially longer than said first duration for extracting slurry filtrate from said slurry within said sealed filtration chamber, said controlling means including means for closing and opening said filter plates.