V-shaped trough filters, rotary assemblies thereof and methods of filtering therewith
AssigneeThe Dehydro Corporation
InventorsForrest B. Stannard, Edward J. Highstreet
Life of this patent
Estimating the term…
Abstract
Filter units for use in filtering liquid suspensions of material prone to form a filter cake resistant to continued flow of filtrate therethrough, e.g., wastewater treatment sludge, have a pair of planar sides arranged in a V-shape. Such sides are formed of rigid filter media, e.g., porous sheets of granular material bound in a resin matrix. Suspension to be filtered is charged into the trough and filtrate is drawn by vacuum through its porous sides. A plurality of such units are arranged side-by-side about a common center in a cylindrical assembly which can be rotated about such center at a predetermined rate to permit each unit to pass through a series of filtering steps to provide new filtering methods.
Claims8
A rotary filter device comprising:
- means designed to mitigate problems in the filtration of sewage sludge or similar liquid suspensions prone to form filter cake resistant to the flow of liquid and thereby rapidly reduce the rate of filtration in conventional filtration units, said device being formed of a plurality of filter units,
- each said unit including
- a pair of rigid, porous sheets formed of granular material fixed in a cured resin matrix,
- said sheets each having a substantially flat front side and a substantially flat back side
- said sheets being spaced apart with their front sides defining therebetween a V-shaped trough having a closed apical portion and an opposed open portion, and
- a web closing each end of said trough,
- said filter units being fixed in a cylindrical assembly with the back sides of adjacent units facing one another with a space therebetween and with said apical portion of each unit positioned around a common center,
- means to apply a vacuum to the back side of each of said sheets, and
- means to rotate said cylindrical assembly about said common center.
A filtration method comprising:
- mitigating problems encountered in filtering sewage sludge or similar liquid suspensions prone to form filter cake resistant to the flow of liquid and thereby rapidly reduce the rate of filtration in conventional filtration methods by,
- providing a rotary filter device formned of a plurality of filter units,
- each said unit comprising:
- a pair of rigid, porous sheets formed of granular material fixed in a cured resin matrix,
- said sheets each having a substantially flat front side and a substantially flat back side
- said sheets being spaced apart with their front sides defining therebetween a V-shaped trough having a closed apical portion and an opposed open portion, and
- an impervious web sealing each end of said trough,
- said filter units being fixed in a cylindrical assembly with the back sides of adjacent units facing one another with a space therebetween and with said apical portion of each unit positioned around a common center,
- means to apply a vacuum to the back side of each of said sheets, and
- means to rotate said cylindrical assembly about said common center as a horizontal axis
- rotating said device about said horizontal axis at a predetermined rate sufficient that each said unit therein passes seriatim through a first quadrant wherein said unit will attain an uppermost position of rotation, a second quadrant, a third quadrant wherein said unit will attain a lowermost position of rotation and a fourth quadrant,
- charging a liquid suspension to be filtered into a V-shaped trough positioned in said first quadrant,
- applying vacuum to a back side of said V-shaped trough in its passage through at least one of said first and second quadrants,
- discharging filter cake from said V-shaped trough in its passage through said second or third quadrant, and
- cleaning said V-shaped trough in its passage through at least one of said third and fourth quadrants.
Dependencies are inferred from the claim text.