Patent ID: 7282019
Filing Date: 2007-10-16
Classification: B04B

Abstract:
1. A centrifuge for separation of particulates from a slurry containing the particulates in a liquid comprising: an outer bowl having a longitudinal axis and a peripheral wall surrounding the axis, the peripheral wall extending from a first end of the bowl to a second opposed end of the bowl; a first discharge arrangement at the first end of the bowl for discharge of the particulates; a second discharge arrangement at the second end of the bowl for discharge of the slurry with the particulates removed; a support assembly mounting the outer bowl for rotation about the longitudinal axis such that the particulates in the slurry within the bowl tend to move radially outwardly of the axis toward an inner surface of the peripheral wall; an inner rotor mounted coaxially within the outer bowl for rotation of an outer wall of the inner rotor about the longitudinal axis, the rotor extending along the bowl from a first end of the rotor adjacent the first end of the bowl to a second end of the rotor adjacent the second end of the bowl; a drive system for driving rotation of the outer bowl and the inner rotor for common rotation in the same direction; the drive system providing a differential in rotational speed between the outer wall of the inner rotor and the inner surface of the peripheral wall of the outer bowl such that the outer wall moves angularly relative to the inner surface of the peripheral wall; the outer wall of the rotor being spaced radially inwardly of the inner surface of the bowl so as to define a space therebetween within which the slurry is separated; a helical auger flight carried on the outer wall of the rotor having an outer edge of the auger flight which moves relative to the inner surface of the peripheral wall so as to tend to carry particulates collecting on the inner surface of the peripheral wall in a direction toward the first end of the bowl and the first discharge arrangement located at the first end; the helical auger flight having openings therein allowing movement of the slurry in the space through the openings toward the second end of the bowl; the bowl and the inner rotor each including a tapered portion such that the outer wall of the rotor and the inner surface of the bowl reduce in diameter toward the first end; the rotor having a slurry inlet opening at the first end of the rotor into a feed chamber within the outer wall of the rotor; a slurry inlet duct for transporting the slurry through the first end of the bowl into the inlet opening in the first end of the rotor; the rotor having at least two outlet openings defined in the outer wall at angularly spaced positions around the axis to allow the slurry to exit through the outer wall from the feed chamber into the space; the outlet openings each having a first side edge and a second side edge with the first and second side edges being generally parallel to each other and to the axis; the rotor having an end accelerator plate of the feed chamber mounted within the outer wall of the rotor for rotation therewith; the end accelerator plate lying generally in a radial plane of the axis such that the slurry flowing generally axially into the feed chamber contacts the accelerator plate of the rotor and moves radially outwardly therefrom through the at least two outlet openings into the space; the end accelerator plate being connected to the outer wall of the rotor at an end edge of each of the at least two outlet openings in the outer wall; at least two discharge surfaces within the feed chamber, each discharge surface having first and second end edges connected to the outer wall; the discharge surfaces each being arranged generally at right angles to the end accelerator plate; with the first edge of a respective one of the discharge surfaces being located at and connected to the first edge of a respective one of the outlet openings in the outer wall and with the second edge of the respective one of the discharge surfaces being located at and connected to the second edge of the next outlet opening in the outer wall so that the respective one of the discharge surfaces bridges a space therebetween; wherein the auger flight has a pitch spacing at a portion of the outer wall of the rotor at the outlet openings which is greater than a pitch spacing at an end of the rotor remote from the slurry inlet opening.