Method and apparatus for de-watering biomass materials in a compression drying process

Claim 1

Apparatus for reducing the moisture content of biomass material comprising: an enclosed chamber having generally vertical side walls and a base forming the bottom of said chamber and movable with respect to said side walls; means for loading moisture ladened biomass material into said chamber; a vertically reciprocable ram having a working face opposed to said movable base, and disposed in said chamber in slidable relationship to said vertical side walls; a conduit means elongate in the generally vertical direction along said side walls for conducting moisture removed from said biomass material out of said chamber; means for applying a predetermined force on said ram for pressing said biomass material against said base; and means forming a select, non-planar profile in said working face, for developing and sustaining a selected pressure gradient across said biomass material as said ram presses thereagainst; said profile converging toward said base and characterized by a plurality of discrete, substantially horizontal stepped portions, and a vertical stepped portion joined with each pair of adjacent horizontal portions; said gradient characterized by a maximum pressure at the center of said chamber diminishing to a minimum pressure near said side walls to drive moisture radially outward from said center, yet provide a minimum pressure sufficiently large to expel moisture out of said chamber through said conduit means; thus to enhance the amount of moisture expelled from said biomass material and chamber as said ram presses against said material.

Claim 9

A method for de-watering biomass material comprising the steps of: (a) feeding said biomass material in batches into a baling chamber; and (b) forcing a compaction ram against a batch of said biomass material, said ram having a non-planar working face engaging said batch of biomass material, said working face having a profile converging toward said batch and characterized by a plurality of discrete, substantially horizontal stepped portions, and a vertical stepped portion joined with each pair of adjacent horizontal step portions and being shaped to create a predetermined negative pressure gradient from the center of said batch toward the walls of said baling chamber, said gradient being sufficiently steep for driving the moisture radially outward from said center, yet providing a pressure at said walls sufficient to expel moisture out of said chamber, thereby enhancing the flow of moisture from said batch to the walls and out of said baling chamber through a conduit means elongate generally in the direction of ram movement along said walls.

Claim 10

A method for de-watering biomass material comprising the steps of: (a) feeding said biomass material in batches into a baling chamber; and (b) forcing a compaction ram against a batch of said biomass material, said ram having a non-planar working face engaging said batch of biomass material, said working face having a profile converging toward said batch and characterized by a plurality of discrete, substantially horizontal stepped portions, and a vertical stepped portion joined with each pair of adjacent horizontal step portions and being shaped to create a predetermined negative pressure gradient from the center of said batch toward the walls of said baling chamber, said gradient being sufficiently steep for driving the moisture radially outward from said center, yet providing a pressure at said walls sufficient to expel moisture out of said chamber, thereby enhancing the flow of moisture from said batch to the walls and out of said baling chamber through a conduit means elongate generally in the direction of ram movement along said walls.