Claims
- 1. A method of treating a fiber suspension utilizing a filter apparatus including a filter surface having openings therein, a counter member having an axially and circumferentially extending counter surface provided with protrusions, each of which has an axial length less than the axial length of said counter surface, said counter member cooperating with the filter surface to define a gap therebetween, said filter surface further including a discharge end and an inlet end, with an accepts volume provided on the opposite side of the filter surface from the gap, the method comprising the steps of:
- (a) under force, drawing the suspension into the gap between the filter surface and the counter member at the inlet end of the filter surface;
- (b) effecting relative movement between the filter surface and the counter member, so that relatively fine accepts pass through the openings in the filter surface and relatively coarse rejects pass toward the discharge end, some suspension at the filter surface being coarser and/or of higher solids concentration than the accepts; and
- (c) during the practice of step (b), diverting the suspension at the filter surface of coarser and/or higher solids concentration than the accepts away from the filter surface and physically moving the coarser and/or higher solids concentration suspension to the rotor surface by means of said protrusions, thereby causing new fiber suspension to be fed towards the filter surface to replace the coarser and/or higher solids concentration suspension.
- 2. A method as recited in claim 1 wherein step (b) is practiced by rotating at least one of the filter surface and counter member with respect to the other.
- 3. A method as recited in claim 1 wherein steps (a)-(c) are practiced with the suspension at a solids consistency of about 0.5-2.5%.
- 4. Apparatus for treating suspension, comprising:
- (a) a filter surface having openings therein, an inlet end and an outlet end, and first and second major surfaces;
- (b) a counter member having an axially and circumferentially extending counter surface;
- (c) means for mounting the counter member and filter surface so that there is a gap between them at the first major surface of the filter surface;
- (d) means for effecting relative movement between the filter surface and the counter member;
- (e) means for introducing suspension into the gap, at the inlet end;
- (f) means for withdrawing suspension passing through the filter surface openings away from the second major surface of the filter surface;
- (g) means for withdrawing suspension not passing through the filter surface openings from the discharge end; and
- (h) plural means arranged on said counter surface and having an axial dimension less than the axial length of the counter member for subjecting some thicker and coarser suspension in the gap at said first major surface of said filter surface to a force component that diverts said thicker and coarser suspension away from the first major surface of the filter surface and physically moves said thicker and coarser suspension to the counter surface.
- 5. Apparatus as recited in claim 4 further comprising (i) means for subjecting some suspension in the gap and not at the filter surface to a force component that moves that suspension toward the filter surface first major surface to replace the suspension moved away from the filter surface first major surface.
- 6. Apparatus as recited in claim 5 wherein said means (h) and (i) comprise a plurality of first and second protrusions, respectively, extending from said counter surface toward said filter surface.
- 7. Apparatus as recited in claim 6 wherein said means (h) further comprises guide plates associated with said first protrusions and each extending outwardly from said counter surface toward said filter surface a greater extent than a said corresponding first protrusion, to define an opening between each said guide plate and a said first protrusion, said opening being dimensioned to allow thicker and or coarser suspension than the accepts to flow therethrough.
- 8. Apparatus as recited in claim 7 wherein said filter surface is cylindrical and said counter surface is cylindrical, substantially concentric with said filter surface; and wherein said means (c) and (d) comprise means for mounting said counter surface for rotation with respect to said filter surface and for effecting relative rotation therebetween, said gap being a radial gap, having an annular shape in cross section.
- 9. Apparatus as recited in claim 8 wherein said guide plate is on the trailing side of the first protrusion with which it is associated in the direction of rotation, and forms an acute angle with the counter surface, opening toward said first protrusion.
- 10. Apparatus as recited in claim 9 wherein said second protrusions comprise backwardly, in the direction of rotation of said counter surface, inclined plates.
- 11. Apparatus as recited in claim 4 wherein said means (h) comprise a plurality of first protrusions, extending from said counter surface toward said filter surface.
- 12. Apparatus as recited in claim 11 wherein said means (h) further comprises guide plates associated with said first protrusions and each extending outwardly from said counter surface toward said filter surface a greater extent than a said corresponding first protrusion, to define an opening between each said guide plate and a said protrusion, said opening being dimensioned to allow thicker and or coarser suspension than the accepts to flow therethrough.
- 13. Apparatus as recited in claim 12 wherein said filter surface is cylindrical and said counter surface is cylindrical, substantially concentric with said filter surface; and wherein said means (c) and (d) comprise means for mounting said counter surface for rotation with respect to said filter surface and for effecting relative radial movement between each other, said gap being a radial gap, having an annular shape in cross section.
- 14. Apparatus as recited in claim 13 wherein said guide plate is on the trailing side of the first protrusion with which it is associated in the direction of rotation, and forms an acute angle with the counter surface, opening toward said first protrusion.
- 15. Apparatus as recited in claim 4 wherein said filter surface is cylindrical and said counter surface is cylindrical, substantially concentric with said filter surface; and wherein said means (c) and (d) comprise means for mounting said counter surface for rotation with respect to said filter surface, and effecting rotation therebetween, said gap being a radial gap, having an annular shape in cross section.
- 16. Apparatus as recited in claim 15 wherein said means (i) comprises a plurality of second protrusions extending from said counter surface toward said filter surface, said second protrusions comprising backwardly, in the direction of rotation, inclined plates.
- 17. Apparatus as recited in claim 4 wherein said filter surface comprises a filter cylinder having grooves formed therein by at least two inclined or curved side surfaces.
- 18. A counter member for an apparatus for treating suspension, adapted to cooperate with a filter surface, said counter member comprising:
- a cylinder having an exterior surface;
- means for mounting said cylinder for rotation about an axis;
- a plurality of first protrusions extending radially outwardly from said cylinder a predetermined distance; and
- guide plates axially adjacent to each of said first protrusions and each extending radially outwardly from said counter surface toward said filter surface a greater extent than a said corresponding first protrusion, to define an opening between each of said guide plates and an adjacent one of said first protrusions, whereby the suspension is drawn under force through said opening and under said guide plate so as to direct the suspension towards said cylinder exterior surface.
- 19. A counter member for an apparatus for treating suspension, adapted to cooperate with a filter surface, said counter member comprising:
- a cylinder having an exterior surface;
- means for mounting said cylinder for rotation about an axis;
- a plurality of first protrusions extending radially outwardly from said cylinder a predetermined distance; and
- guide plates adjacent to said first protrusions and each extending radially outwardly from said counter surface toward said filter surface a greater extent than a said corresponding first protrusion, to define an opening between each of said guide plate and a said protrusion, whereby the suspension is drawn under force through said opening and under said guide plate so as to direct the suspension towards said cylinder exterior surface; and
- wherein each said guide plate is on the trailing side, in the intended direction of rotation of said cylinder, of the first protrusion with which it is associated, and forms an acute angle with the cylinder surface, opening toward said first protrusion.
- 20. A counter member as recited in claim 19 further comprising a plurality of second protrusions extending radially outwardly from said cylinder surface.
- 21. A counter member as recited in claim 20 wherein said second protrusions comprise backwardly, in the intended direction of rotation of said cylinder, inclined plates.
Priority Claims (1)
Number |
Date |
Country |
Kind |
892356 |
May 1989 |
FIX |
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Parent Case Info
This is a continuation of application Ser. No. 07/524,752, filed May 17, 1990, now abandoned.
US Referenced Citations (16)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3006482 |
Oct 1981 |
DEX |
56715 |
Mar 1980 |
FIX |
Continuations (1)
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Number |
Date |
Country |
Parent |
524752 |
May 1990 |
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