US 4,109,872 AGranted

Pulping apparatus for liquid slurry stock

AssigneeThe Black Clawson Company

InventorJoseph W. Couture

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Abstract

A rotor for a pulper for liquid slurry stock includes a rotor body provided with circumferentially spaced composite vanes, each of which includes a defibering portion and a pumping portion. The defibering portion constitutes the outer end portion of each vane and is of relatively small axial dimensions. The pumping portion constitutes the upper portion of each composite vane and is of substantially greater axial dimensions with its upper surface of convex airfoil shape. The leading face of each pumping portion is essentially plane and inclined forwardly to overhang the trailing edge of the adjacent pumping portion and define therewith a groove in which the stock is channeled for forced centrifugally outward flow. In the preferred embodiment, the rotor cooperates with a frustoconical extraction plate, and the defibering vane portions have their undersurfaces inclined to match the inclination of the extraction plate and are proportioned to extend fully across the extraction plate.

Claims10

Dependent claims

A rotor for use in pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of the stock and a perforated annular extraction plate forming a portion of a wall of the tub, comprising:

(a) a rotor body adapted to be mounted for rotation on the central axis thereof in predetermined direction in the tub in cooperative centered relation with the extraction plate and including a hub portion and a plurality of composite vanes projecting generally radially from said hub portion in circumferentially spaced relation,
(b) each of said composite vanes including a defibering portion and a pumping portion,
(c) said defibering portion constituting the radially outer end portion of said vane and having substantially smaller axial dimensions than said hub portion,
(d) means forming an essentially plane leading face on each said defibering vane portion extending tangentially of said rotor body in said direction of rotation from a radius to the radially outer end thereof and defining with said radius an angle a of substantially less than 45.degree.,
(e) said pumping portion constituting the radially inner portion of each said composite vane but being of substantially lesser radial dimensions and substantially greater axial dimensions than said defibering portion,
(f) means forming a leading face on each said pumping portion of such configuration as viewed axially of said rotor body that the angle b defined by a radius and a tangent to the outer end thereof is sufficiently larger than said angle a to promote efficient vortical circulation of the stock, and
(g) said leading face on each of said pumping portions being plane in axial section and forwardly inclined into partially overhanging relation with the forwardly adjacent said pumping portion to define therewith a groove in the upper surface of said body.

4 more elements

In apparatus for pulping liquid slurry stock, the combination of

(a) a cylindrical tub for receiving a quantity of stock,
(b) said tub having a bottom wall comprising a plane center portion and an annular perforate extraction plate surrounding an adjacent said plane center portion,
(c) a rotor body including a hub portion and a plurality of composite vanes projecting outwardly from said hub portion in circumferentially spaced relation,
(d) means mounting said rotor body for rotation in a predetermined direction in centered and closely spaced relation with said horizontal portion of said bottom wall,
(e) each of said composite vanes including a defibering portion and a pumping portion,
(f) said defibering portion constituting the radially outer end portion of said vane and having substantially smaller axial dimensions than said hub portion,
(g) means forming an essentially plane leading face on each said defibering vane portion extending tangentially of said rotor body in said direction of rotation from a radius to the radially outer end thereof and defining with said radius an angle a of substantially less than 45.degree.,
(h) said leading face being forwardly inclined to define an angle of less than 90.degree. with said extraction plate,
(i) said pumping portion constituting the upper portion of each said composite vane but being of substantially lesser radial dimensions and substantially greater axial dimensions than said defibering portion,
(j) means forming a leading face on each said pumping portion of such configuration as viewed axially of said rotor body that the angle b defined by a radius and a tangent to the outer end thereof is sufficiently larger than said angle a to promote efficient vortical circulation of the stock,
(k) said leading face on each of said pumping portions being essentially plane in axial section and forwardly inclined into partially overhanging relation with the forwardly adjacent said pumping portion to define therewith a groove in the upper surface of said body,
(l) said rotor being dimensioned to provide spaces between adjacent said vanes extending substantially the full radial dimension of said extraction plate, and
(m) said defibering vane portions being substantially equal in diameter to said extraction plate to extend fully thereacross.

10 more elements

Dependencies are inferred from the claim text.