Three-phase centrifuge

Claim 2

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. and vane means mounted on said hub and extending between adjacent flights, said vane means being located adjacent said portion of said inner annular surface which is decreasing in diameter, said vane means being adapted to exclude said second lIquid from that portion of the separation chamber in which said vane means is positioned.

Claim 3

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising; a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. radically extending rib means mounted adjacent to said other end, said radially extending rib means being adapted to control the rotational velocity of one of said liquids with respect to said bowl; f. and screen means mounted adjacent said plurality of radially extending ribs, said screen means being adapted to reduce the turbulence of said first liquid and said second liquid being discharged through said first and said second groups of liquid discharge openings.

Claim 4

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising; a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. radically extending rib means mounted adjacent to said other end, said radially extending rib means being adapted to control the rotational velocity of one of said liquids with respect to said bowl; f. and screen means mounted adjacent said plurality of radially extending ribs, said screen means being adapted to reduce the turbulence of said first liquid and said second liquid being discharged through said first and said second groups of liquid discharge openings.

Claim 5

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. and means defining an annular channel on the exterior of said other end adjacent to said first group of liquid discharge openiNgs, said annular channel opening in an inward direction and being adapted to receive said first liquid discharged through said first group of liquid discharge openings, and further including a skimmer tube having an inlet for receiving said first liquid from said channel, said inlet being disposed within said channel, said first group of liquid discharge openings extending from the interior to the exterior of said bowl in a radially inward direction, and said second group of liquid discharge openings extending from the interior to the exterior of said bowl in a radially outward direction, said first group of liquid discharge openings terminating adjacent said annular channel, said second group of liquid discharge openings terminating at the outer annular surface of said bowl.

Claim 6

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. and means defining an annular channel on the exterior of said other end adjacent to said first group of liquid discharge openiNgs, said annular channel opening in an inward direction and being adapted to receive said first liquid discharged through said first group of liquid discharge openings, and further including a skimmer tube having an inlet for receiving said first liquid from said channel, said inlet being disposed within said channel, said first group of liquid discharge openings extending from the interior to the exterior of said bowl in a radially inward direction, and said second group of liquid discharge openings extending from the interior to the exterior of said bowl in a radially outward direction, said first group of liquid discharge openings terminating adjacent said annular channel, said second group of liquid discharge openings terminating at the outer annular surface of said bowl.

Claim 7

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings, said first group of openings extending from the interior to the exterior of said bowl in a radially inward direction, said second group of openings extending from the interior to the exterior of said bowl in a radially outward direction, said second group of liquid discharge openings terminating at the outer annular surface of said bowl; b. annular ring dam means mounted adjacent to said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber.

Claim 8

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings, said first group of openings extending from the interior to the exterior of said bowl in a radially inward direction, said second group of openings extending from the interior to the exterior of said bowl in a radially outward direction, said second group of liquid discharge openings terminating at the outer annular surface of said bowl; b. annular ring dam means mounted adjacent to said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber.

Claim 9

A three-phase centrifuge according to claim 4 including an annular cup-shaped member, said cup-shaped member comprising a base portion and an annular flange portion extending from said base portion, said flange portion having an inner annular surface which increases in diameter in a direction away from said base portion, said base portion mounted to the exterior of said other end and said flange portion extending in a direction toward said one end of said bowl, the inner annular surface of said flange portion and the outer annular surface of said bowl defining an annular zone, the outer annular surface of said flange portion having a plurality of annular grooves disposed therein, means surrounding said flange portion and cooperating with said annular grooves to define a first space and a second space on either side of said means, said annular cup-shaped member and said means being adapted to rotate with respect to each other, said annular zone communicating with said second space, said first group of liquid discharge openings extending from the interior of said bowl to said first space, and said second group of liquid discharge openings extending from the interior of said bowl to said annular zone.

Claim 10

A three-phase centriFuge according to claim 5 in which said base portion includes a radially inwardly extending rim defining an annular channel between said base portion and said other end, said annular channel being disposed adjacent said first group of liquid discharge openings.

Claim 11

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. and means defining an annular channel on the exterior of said other end adjacent to said first group of liquid discharge openings, said annular channel opening in an inward direction and being adapted to receive said first liquid discharged through said first group of liquid discharge openings, and further including a skimmer tube having an inlet for receiving said first liquid from said channel, said inlet being disposed within said channel.

Claim 12

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. and means defining an annular channel on the exterior of said other end adjacent to said first group of liquid discharge openings, said annular channel opening in an inward direction and being adapted to receive said first liquid discharged through said first group of liquid discharge openings, and further including a skimmer tube having an inlet for receiving said first liquid from said channel, said inlet being disposed within said channel.

Claim 13

A three-phase centrifuge according to claim 7, including annular underdam ring means mounted adjacent said group of liquid discharge openings, said annular underdam ring means being adapted to prevent discharge of said second liquid through said first group of liquid discharge openings.

Claim 14

A three-phase centrifuge according to claim 7 including a radially extending rib means mounted on the interior of said bowl adjacent said other end, said radially extending rib means being adapted to control the rotational velocity of one of said liquids with respect to said bowl and annular underdam ring means mounted adjacent said first group of liquid discharge openings, said annular underdam ring means being adapted to prevent discharge of said second liquid through said first group of liquid discharge openings.

Claim 15

A three-phase centrifuge for separating solids, a first liquid and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance frOm the axis of rotation than said first group of liquid discharge openings; b. means defining an annular channel on the exterior of said other end adjacent said first group of liquid discharge openings, said annular channel being adapted to receive said first liquid discharged through said first group of liquid discharge openings and further including a skimmer tube having an inlet for receiving said first liquid from said annular channel, said inlet being disposed within said channel; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber.

Claim 16

A three-phase centrifuge for separating solids, a first liquid and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance frOm the axis of rotation than said first group of liquid discharge openings; b. means defining an annular channel on the exterior of said other end adjacent said first group of liquid discharge openings, said annular channel being adapted to receive said first liquid discharged through said first group of liquid discharge openings and further including a skimmer tube having an inlet for receiving said first liquid from said annular channel, said inlet being disposed within said channel; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber.

Claim 17

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. annular underdam ring means mounted adjacent said first group of liquid discharge openings, said annular underdam ring means being adapted to prevent discharge of said second liquid through said first group of liquid discharge openings.

Claim 18

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. annular underdam ring means mounted adjacent said first group of liquid discharge openings, said annular underdam ring means being adapted to prevent discharge of said second liquid through said first group of liquid discharge openings.

Claim 19

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. radially extending rib means mounted adjacent to said other end, said radially extending rib means being adapted to control the rotational velocity of one of said liquids with respect to said bowl.

Claim 20

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. radially extending rib means mounted adjacent to said other end, said radially extending rib means being adapted to control the rotational velocity of one of said liquids with respect to said bowl.

Claim 21

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. a scraper member mounted adjacent the distal edges of one of said flights, said scraper member being disposed adjacent said inner annular surface, and adjacent said other end of said bowl, and adapted to rotate about said axis upon rotation of said screw conveyor to remove accumulations of solids on said inner annular surface.

Claim 22

A three-phase centrifuge for separating solids, a first liquid, and a second liquid, each having different specific gravities, from feed comprising a liquids-solids mixture, said centrifuge comprising: a. an elongated hollow bowl of circular cross section mounted for rotation about an axis, said bowl having an inner annular surface with a portion thereof decreasing in diameter approaching one end of said bowl, said bowl having a solids discharge opening disposed at said one end, the other end of said bowl having disposed therein a first group of liquid discharge openings for discharge of the first liquid, and a second group of liquid discharge openings for discharge of the second liquid, said second group of liquid discharge openings opening into the interior of said bowl at said other end at a lesser distance from the axis of rotation than said first group of liquid discharge openings; b. annular ring dam means mounted adjacent said second group of liquid discharge openings, said ring dam means serving as a weir over which said second liquid flows upon being discharged; c. a screw conveyor disposed within said bowl and mounted for coaxial rotation therein, said conveyor including an axially elongated hub radially spaced from said bowl to define therewith an annular separating chamber, flights mounted on said hub for movement therewith, said flights having their distal edges generally complementing the inside contour of said bowl; d. feed means having an outlet, said outlet being positioned between said one end and said other end of said bowl, said outlet being adapted to introduce said feed into said separating chamber; e. a scraper member mounted adjacent the distal edges of one of said flights, said scraper member being disposed adjacent said inner annular surface, and adjacent said other end of said bowl, and adapted to rotate about said axis upon rotation of said screw conveyor to remove accumulations of solids on said inner annular surface.