Dual zone refiner with separated discharge flow control

A refiner for treating a low consistency fibrous slurry of feed material, comprising:

• a casing;
• a rotor member situated within the casing and having a first plurality of grinding faces;
• a shaft penetrating the casing and connected to the rotor member, for spinning the rotor member about a rotation axis;
• means within said casing, forming a second plurality of grinding faces juxtaposed with said first plurality of grinding faces and thereby defining a plurality of refining gaps therebetween;
• means for directing said feed material into the plurality of refining gaps, whereby each refining gap treats feed material and has a respective outflow rate;
• means within the casing for directing the outflow from each refining gap, to a unique discharge line out of the casing;
• a control valve situated in each discharge line;
• and
• means for selectively controlling said valves to differentially affect the flow rates through the discharge lines.

A refiner for mechanically treating fibrous slurry, comprising:

• a casing;
• a rotor member situated within the casing and having first and second grinding faces on respective sides of a vertical plane passing through the rotor member;
• a horizontal shaft penetrating the casing and connected to the rotor member perpendicularly to said plane, for spinning the rotor member about a horizontal rotation axis;
• means within said casing, forming a third grinding face juxtaposed with said first grinding face and thereby defining a first variable width refining gap therebetween;
• means within said casing, forming a fourth grinding face juxtaposed with said second grinding face and defining a second variable width refining gap therebetween;
• means for directing feed material into the first and second refining gaps simultaneously, whereby a first outflow rate discharged from the casing from the first refining gap varies with the first refining gap width and a second outflow rate discharged from the casing from the second refining gap varies with the second refining gap width;
• means for measuring the first and second refining gap widths and generating respective first and second gap width signals;
• and
• control means responsive to said gap width signals, for adjusting at least one of the first and second outflow rates to thereby vary the width of at least one of said refining gaps.

A refiner for mechanically treating fibrous slurry, comprising:

• a casing;
• a rotor member situated within the casing and having first and second grinding faces on respective sides of a vertical plane passing through the rotor member;
• a horizontal shaft penetrating the casing and connected to the rotor member perpendicularly to said plane, for spinning the rotor member about a horizontal rotation axis;
• means within said casing, forming a third grinding face juxtaposed with said first grinding face and thereby defining a first variable width refining gap therebetween;
• means within said casing, forming a fourth grinding face juxtaposed with said second grinding face and defining a second variable width refining gap therebetween;
• means for directing feed material into the first and second refining gaps simultaneously, whereby a first outflow rate discharged from the casing from the first refining gap varies with the first refining gap width and a second outflow rate discharged from the casing from the second refining gap varies with the second refining gap width;
• divider means extending between the casing and the rotor member, for maintaining isolation between the outflow emerging from the first gap for discharge through a first discharge opening in the casing and the outflow emerging from the second refining gap for discharge through a second discharge opening in the casing;
• means for measuring the first and second outflow rates discharged through said openings in the casing and generating respective first and second discharge flow rate signals;
• and
• control means responsive to said flow rate signals, for adjusting at least one of the first and second outflow rates to equalize said outflow rates within a predetermined tolerance.