Compression rings for column relief in continuous cooking vessels
AssigneeAndritz Inc.
InventorJay K. Sheerer
Life of this patent
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Abstract
The flow of a liquid slurry of comminuted cellulosic fibrous material (e.g. wood chips) in a vertical vessel is made more uniform by providing a plurality of vertically spaced sets of either substantially continuous or discontinuous protrusions which extend inwardly from the internal surface of the vessel a maximum distance of between about 2-12 inches. A preferred vessel is a continuous or batch digester. The protrusions may have an arcuate, rectangular, isosceles or scalene triangular, right triangular, or trapezoidal cross-section, and may be spaced from each other vertically between about 1-12 feet, and have a height of between about 1-3 feet. Discontinuous protrusions have a preferred arcuate spacing of between 1-10 feet.
Claims25
A method of treating a liquid slurry of comminuted cellulosic fibrous material in a substantially vertical vessel having an internal surface, comprising:
- (a) introducing the slurry into the vessel so that the slurry moves substantially downwardly in the vessel in a column;
- and
- (b) at a plurality of vertically spaced locations in the vessel temporarily relieving compressive forces within the column and the normal forces on the internal surface of the vessel so that friction between the comminuted material and the vessel internal surface is temporarily decreased, or substantially eliminated, providing more uniform flow of the material in the vessel.
A substantially vertical vessel having an internal surface and comprising:
- a plurality of vertically spaced sets of circumferentially discontinuous protrusions extending inwardly from said internal surface a maximum distance of about 2-12 inches:
- an inlet at or near a top portion of said vessel;
- and
- an outlet at or near a bottom portion of said vessel.
A method of treating a liquid slurry of comminuted cellulosic fibrous material in a substantially vertical vessel having an internal surface, comprising:
- (a) introducing the slurry into the vessel so that the slurry moves substantially downwardly in the vessel in a column;
- and
- (b) at a plurality of vertically spaced locations in the vessel, causing the slurry to flow over surface manifestations which extend into the vessel a maximum distance of between about 1-12 inches.
A substantially vertical vessel having an internal surface, and comprising:
- an inlet at or adjacent a top portion of said vessel;
- an outlet at or adjacent a bottom portion of said vessel;
- and
- at least one substantially continuous annular protrusion connected to said internal surface and in a substantially horizontal plane, and having a maximum spacing from said internal surface of between about 1-12 inches, said protrusion having a cross-section selected from the group consisting essentially of right, isosceles, or scalene triangular, arcuate, and rectangular.
Dependencies are inferred from the claim text.