Patent ID: 8309711

Claim:
A method of dewatering and washing a corn starch and water slurry to form a filter cake from said corn starch and water slurry, said method comprising the steps of: feeding, under pressure, said corn starch and water slurry into a filter housing, wherein said filter housing is of uniform cross-sectional area and includes a plurality of vertical filter elements; passing said water through said vertical filter elements as filtrate; forming a cake of corn starch on said vertical filter elements; ceasing said slurry feeding; allowing any remaining slurry and/or filtrate in said filter housing to drain; feeding a wash liquid into the filter housing such that it flows through the cake and into a filtrate space of said vertical filter elements, displacing any liquid in or around said cake into a filtrate collection header of said filter housing; ceasing said wash liquid feeding; draining the wash liquid through an exhaust port of said filter housing; introducing a gas flow into said filter housing to dry said cake by forcing any remaining wash liquid out of said cake; ceasing said gas flow and opening a drain to allow most of the gas and any remaining wash liquid to exit; opening a cake discharge valve located at the bottom of said filter housing, said cake discharge valve defining an opening having a cross-sectional area that is substantially equal to the cross-sectional area of said filter housing; backpulsing a gas out through said filter elements in a direction opposite to a filtration direction to break and release the filter cake from said filter elements of said filter housing; and allowing released cake to exit through said opening in said discharge valve.