Stationary diffuser
OwnerOliver A. Laaksoinventor
Life of this patent
Estimating the term…
Abstract
A method and apparatus for effecting washing, bleaching, or thickening, etcetera of paper pulp or the like utilizes stationary screens, yet provides efficient treatment without significant screen clogging. Pulp introduced into the bottom of a cylindrical upright vessel is caused to flow in particular radial segments and channels. Introduction of pulp into all channels of a particular radial segment, extraction of withdrawn liquid from the radial segments, removal of treated pulp from the top of the vessel, and the introduction of treating liquid between the stationary screens, are coordinated so that uniform treatment of the upwardly flowing pulp results.
Claims31
Apparatus for treating a suspension comprising:
- an upright cylindrical vessel;
- a central shaft mounted for rotation within said cylindrical vessel about the axis of said cylindrical vessel;
- a plurality of annular stationary screens disposed within said vessel and spaced from each other and from said central shaft;
- a plurality of radially extending extraction arms physically and hydraulically connected to said stationary annular screens, said extraction arms partitioning said vessel into a plurality of radial segments of substantially the same cross-sectional area, and said screens partitioning each radial segment into a plurality of vertically extending channels;
- and a suspension inlet means mounted below said extraction arms and screens and operatively connected to said shaft, said inlet means comprising means for introducing suspension into a bottom portion of said vessel with a cross-sectional area substantially the same size and shape as one of said radial segments.
Apparatus for treating a suspension comprising:
- an upright cylindrical vessel;
- a central shaft mounted for rotation within said cylindrical vessel about the axis of said cylindrical vessel;
- a plurality of annular stationary screens disposed within said vessel and spaced from each other and from said central shaft;
- a plurality of radially extending extraction arms physically and hydraulically connected to said stationary annular screens, aaid extraction arms partitioning said vessel into a plurality of radial segments of substantially the same cross-sectional area, and said screens partitioning each radial segment into a plurality of vertically extending channels;
- treated suspension removing means located adjacent to the top of said vessel, above said stationary screens, for simultaneously removing all of the suspension along a radius of said vessel;
- and means for connecting said suspension removing means to said central shaft for rotation therewith.
Apparatus for treating a suspension comprising:
- an upright cylindrical vessel a central shaft mounted for rotation within said cylindrical vessel about the axis of said cylindrical vessel;
- a plurality of annular stationary screens disposed within said vessel and spaced from each other and from said central shaft;
- a plurality of radially extending extraction arms physically and hydraulically connected to said stationary annular screens, said extraction arms partitioning said vessel into a plurality of radial segments of substantially the same cross-sectional area, and said screens partitioning each radial segment into a plurality of vertically extending channels;
- wherein each of said stationary screen structures comprises at least one screen surface and an interior supporting structure extending substantially parallel to the axis of rotation of said shaft;
- and means for mounting each said screen surface with respect to said supporting structures so that a top portion of said screen surface is closer to its respective supporting structure than a bottom portion of said screen surface, providing an increased cross-sectional area of flow as suspension moves upwardly in said vessel.
Apparatus for treating a suspension comprising:
- an upright cylindrical vessel a central shaft mounted for rotation within said cylindrical vessel about the axis of said cylindrical vessel;
- a plurality of annular stationary screens disposed within said vessel and spaced from each other and from said central shaft;
- a plurality of radially extending extraction arms physically and hydraulically connected to said stationary annular screens, said extraction arms partitioning said vessel into a plurality of radial segments of substantially the same cross-sectional area, and said screens partitioning each radial segment into a plurality of vertically extending channels;
- and wherein each screen segment of each of said screen structures in a particular radial segment is hydraulically connected to the same extraction arm, and only a single extraction arm;
- and further comprising a plurality of extraction conduits, one extending from each of said extraction arms;
- and extraction valve means for controlling the flow of liquid from each extraction arm.
Apparatus for the continuous treatment of a suspension in a cylindrical vessel comprising:
- a cylindrical vertical vessel;
- a plurality of annular stationary screens disposed in said vessel, and concentric therewith;
- means defining a plurality of radial segments, and a plurality of vertical channels in each radial segment, in said vessel;
- means for introducing suspension, adjacent the vessel bottom, to flow upwardly in the vessel in a moving suspension column into a cross-sectional area in the vessel corresponding to that of approximately one of the radial segments;
- means for substantially continuously withdrawing liquid from the majority of the stationary screens' area;
- means for terminating extraction from the screens in each radial segment approximately when the suspension is being introduced therein;
- and means for continuously removing from a top portion of said vessel, above the level of said screens, a portion of the entire radial extent of the suspension at the cross-sectional area of the top of the column preceding the radial segment into which the suspension is being introduced at the bottom of the column.
Apparatus as recited in cliam 27 wherein each said nozzle assembly comprises an axially-extending fluid introducing portion, and wherein said surface means comprises a substantially annular wall structure substantially parallel to the walls of said cylindrical vessel, and having an increasing cross-sectional area from a point immediately following said fluid introducing structre in the direction of rotation of said nozzle assembly to a point of connection to said fluid introducing portion.
Dependencies are inferred from the claim text.