# US 4,396,509 A · Device for extraction of liquid from suspensions in movement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,509 A - Document ID: US4396509A - Status: Granted - Kind: A - Application number: 06/221,810 - Filed: 1980-12-31 - Granted: 1983-08-02 - Earliest claimed: 1980-01-10 - Assignees: Kamyr, Inc. - Inventors: Tore Foyn - Web page: https://patentgrep.com/patent/US4396509A ## CPC - D21F 1/66: Pulp catching, de-watering, or recovering; Re-use of pulp-water - B01D 29/25: open-ended {the arrival of the mixture to be filtered and the discharge of the concentrated mixture are situated on both opposite sides of the filtering element} - B01D 29/72: involving vibrations - B01D 35/22: Directing the mixture to be filtered on to the filters in a manner to clean the filters {(B01D29/904 takes precedence)} - D21F: PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A screen assembly is provided for the dewatering of flowing suspensions. A screen body having a perforated wall has a first slide bearing mounted at a first end thereof, and a second slide bearing mounted to a second end thereof. The screen body is mounted in a generally cylindrical container through which suspension to be dewatered flows in a first direction, and the screen slide bearings engage first and second bearing surfaces mounted interiorly of the container. The bearing surfaces have different effective cross-sectional areas. The screen between the first and second ends thereof and the bearing surfaces define a screen cavity volume, and a rod attached to a linear actuator moves the screen in the first direction, and in a second direction opposite the first direction, so that the cavity volume changes during movement of the screen. The screen and bearings may have any desired configuration or cross-sectional area. ## Claims ### Claim 1 Apparatus for continuously dewatering flowing suspensions comprising: a generally cylindrical container having a continuously open inlet at one end thereof through which suspension to be dewatered continuously flows on a first direction, and a continuously open outlet at the other end thereof, said container having an axis extending generally parallel to or concentric with said first direction; screen means distinct from and unassociated with said inlet and outlet for removal of a portion of liquid from the suspension flowing through said container, and extending generally along the axis of said container in which it is disposed, said screen means comprising a first end and a second end opposite said first end and spaced generally along said axis from said first end; first and second support members mounted interiorly of said container and parallel to, or concentric with, said first direction, said first and second support members having different effective cross-sectional areas and being continuous and unapertured along the entire length thereof; first and second sealing bearing means, and first and second bearing surface means cooperating with said first and second sealing bearing means; one of said bearing means and said bearing surface means being mounted on said screen means at said first and second ends thereof, and the other of said bearing means and said bearing surface means being mounted on said first and second support members, and being continuous over the entire effective length of said support members; said screen means, between said first and second ends thereof, and said support members defining a screen cavity volume; an outlet extending from said screen cavity volume to an area remote from said containers; and mechanical means for moving said screen means in said first direction with respect to said support members, and in a second direction opposite said first direction, with said sealing bearing means and said bearing surface means cooperating, so that the cavity volume changes during movement of said screen means, so that said cavity volume increases during movement of said screen means in said first direction. ### Claim 2 (depends on 1) Apparatus as recited in claim 1 wherein said container is substantially circular in cross-section, and said bearing surface means are annular. ### Claim 3 (depends on 1) Apparatus as recited in claim 1 wherein said container in quadrate in cross-section and said bearing surface means are planar. ### Claim 4 (depends on 1) Apparatus as recited in claim 1 wherein said mechanical means comprise a rod extending axially in said container, and a linear actuator for effecting linear reciprocatory movement of said rod. ### Claim 5 (depends on 4) Apparatus as recited in claim 4 wherein said linear actuator comprises means for moving said screen means in said first direction at a first speed, and means for moving said screen means in said second direction at a second speed greater than said first speed. ### Claim 6 (depends on 4) Apparatus as recited in claim 4 wherein said mechanical means further comprises a spider connection connecting said rod to said screen means. ### Claim 7 (depends on 1) Apparatus as recited in claim 1 wherein said screen means comprises a plurality of screen bodies including a first body comprising first and second planar screens interconnected for common movement by at least one connector, and a second body comprising third and fourth planar screens interconnected for common movement by at least one connector. ### Claim 8 (depends on 7) Apparatus as recited in claim 7 wherein said first and second support members assocaited with said first body comprise an interior surface of a wall of said container and a parallel surface of an interior divider in said container, and a planar shelf spaced from and substantially parallel to said wall interior surface and a parallel surface of said interior divider, respectively. ### Claim 9 (depends on 8) Apparatus as recited in claim 8 wherein said mechanical means comprises a rod connected by a fork to both said screen bodies, and to a single linear actuator. ### Claim 10 (depends on 8) Apparatus as recited in claim 8 wherein said outlet penetrates said wall interior surface, and wherein said at least one connector is a tubular conduit interconnecting said first and second screens and having a larger interior cross-sectional area at the interconnection thereof to said second screen than at the interconnection thereof to said first screen. ### Claim 11 (depends on 1) Apparatus as recited in claim 1 wherein said container is substantially circular in cross-section, and wherein said screen means comprises a plurality of concentric annular screen bodies, said bodies collectively having screen surfaces facing each other and distributed over the cross-section of said container. ### Claim 12 (depends on 1) Apparatus as recited in claim 1 wherein said first support member includes an interior surface of said container extending substantially parallel to said first direction. ### Claim 13 (depends on 12) Apparatus as recited in claim 12 wherein said second support member includes a tubular sleeve concentric with said container interior surface. ### Claim 14 (depends on 12) Apparatus as recited in claim 12 wherein said first support member includes a first cylindrical interior member substantially concentric with said container, and said second support member includes a second cylindrical interior member substantially concentric with said container and spaced from said first member along said first direction. ### Claim 15 (depends on 14) Apparatus as recited in claim 14 wherein said first cylindrical interior member is hollow, and wherein said outlet extends from said first cylindrical interior member through a wall of said container. ### Claim 16 (depends on 1) Apparatus as recited in claim 1 wherein said screen means comprises first and second distinct screen bodies, each defining a cavity volume; and wherein said first and second support members cooperating with said first screen body comprise the interior surface of said container and a tubular sleeve concentric with said container interior surface, respectively; and wherein first and second support members are provided associated with said second distinct screen body, said first and second support members comprising a pair of cylindrical interior members having different cross-sectional areas, spaced from each other in said first direction, and disposed concentrically with said tubular sleeve. ### Claim 17 (depends on 1) Apparatus as recited in claim 1 wherein said bearing means are mounted on said first end and second end of said screen means for movement with said screen means, and wherein said bearing surface means are mounted stationarily on said support members, for cooperation with said sealing bearing means.