US 4,362,536 A · Pulp degassing

Abstract

Pulp degassification is effected by a structure that may be mounted on a pulp treatment vessel, such as an oxygen reactor blow tank. The degassifier includes a housing that is substantially circular in cross-section and tapers from a first end to a second end along a central axis. A pulp inlet is adjacent the first end and introduces pulp tangentially and an outlet is adjacent the second end extending concentrically with the central axis. A blade assembly is mounted for rotation about an axis generally coincident with the housing central axis, and the blade assembly is rotated to impart a high speed rotational velocity component to the pulp as it enters the housing. A gas outlet is adjacent the housing first end, vertically above the housing second end, and adjacent the central axis. A conically shaped baffle or the like is provided surrounding the gas outlet to prevent short-circuiting of pulp from the inlet to the gas outlet.

Claims7

Dependent claims

A method of degassifying pulp having a consistency of about 6-15%, utilizing a degassifier comprising a housing tapering from a first end to a second end thereof along a central axis with a pulp inlet adjacent to the first end and a pulp outlet adjacent to the second end, and a rotatable blade assembly adjacent to the pulp inlet, and a gas outlet adjacent to the first end, comprising the steps of:

feeding the pulp into the housing through the pulp inlet with a velocity component intersecting a plane containing the central axis of the housing;
rotating the blade assembly to impart a high speed rotational velocity component to the pulp as it enters the housing;
effecting movement of the pulp along the central axis of the housing toward the pulp outlet while gas within the pulp is being squeezed out;
and
withdrawing gas separated from the pulp through the gas outlet adjacent the central axis and pulp inlet of the housing.

2 more elements

A pulp degassifier comprising

a housing substantially circular in cross-section and tapering inwardly from a first end thereof toward a second end thereof along a central axis;
means defining a pulp inlet to said housing adjacent said first end thereof, said pulp inlet extending along a line intersecting a plane containing said central axis;
means defining a pulp outlet adjacent said second end of said housing;
a blade assembly;
means for mounting said blade assembly adjacent said pulp inlet for rotation about an axis generally coincident with said housing central axis;
means defining a gas outlet adjacent said housing first end and adjacent said central axis;
means for preventing short-circuiting of pulp from said pulp inlet to said gas outlets, comprising a conically shaped shroud surrounding said gas outlet;
means for rotating said blade assembly about said axis of rotation thereof so that said blade assembly imparts a high velocity to the pulp;
said means for mounting said blade assembly for rotation comprising a shaft extending centrally into said housing through said first end thereof;
and
said means defining a gas outlet comprising:
a top plate capping off said housing first end and receiving said shaft through a central opening thereof;
means defining a plurality of openings in said top plate surrounding said shaft;
and a conduit connected to each of said plurality of openings formed in said top plate surrounding said shaft.

11 more elements

A pulp degassifier comprising

a housing substantially circular in cross-section and tapering inwardly from a first end thereof toward a second end thereof along a central axis;
means defining a pulp inlet to said housing adjacent said first end thereof, said pulp inlet extending along a line intersecting a plane containing said central axis;
means defining a pulp outlet adjacent said second end of said housing;
a blade assembly comprising a hub, a plurality of blades, and interconnections between said hub and blades;
and wherein each of said blades having:
a radially-outwardmost edge having a taper substantially parallel to said housing taper, and spaced in close proximity to said housing;
and a radially-inwardmost edge extending substantially parallel to the radially-outwardmost edge of said blade;
means for mounting said blade assembly adjacent said pulp inlet for rotation about an axis generally coincident with said housing central axis;
means for rotating said blade assembly about said axis of rotation thereof so that said blade assembly imparts a high velocity to the pulp;
means defining a gas outlet adjacent said housing first end and adjacent said central axis;
and
means for preventing short-circuiting of pulp from said pulp inlet to said gas outlet, comprising a conically shaped shroud surrounding said gas outlet, the conical taper of said shroud being substantially the same as the taper of said blades radially-inwardmost edges, and said shroud and said blades being slightly radially spaced from each other, and axially overlapping.

9 more elements

Dependencies are inferred from the claim text.

Pulp degassing

Life of this patent

Pulp degassing

Life of this patent

Abstract

Claims7