US4331534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and arrangement for the de-inking of pulp suspensions
Assignee: Stora Feldmuehle AG
•
Filing: 1979-08-18
•
Granted: 1982-05-25
•
Expires: 1999-08-18
Abstract
Abstract A pulp suspension of waste paper which is laden with air bubbles is introduced into a flotation cell. Fine air bubbles rise through the pulp suspension toward the top. Printing ink and other impurities are deposited on the bubbles which form a foam layer on the surface of the pulp suspension. The foam which is laden with impurities is drawn off from the surface. The fibers which have been subjected to preliminary purification in this manner sink downwardly. For reducing the number of cells connected in series to fewer than a third, while obtaining the same degree of whiteness, the fibers which were subjected to preliminary purification are drawn off and are once again supplied to the flotation cell in the form of an air-laden pulp suspension. Alternatively, instead of the air-laden pulp suspension, a water-air suspension can be injected. The air bubbles which are thus introduced once again rise toward the top and traverse the sinking fibers in a counterflow. As a result, an intensive air-pulp contact is created.
Inventors
- 👤 Wolfgang Barnscheidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:09
CPC Classifications
D; D21; D21B; D21B1/00; D21B1/04; D21B1/12; D21B1/30; D21B1/32; D21B1/325; D21B1/327; B; B03; B03D; B03D1/00; B03D1/14; B03D1/1443; B03D1/1456; B03D1/1462; B03D1/24; D21F; D21F1/00; D21F1/66; D21F1/70; B03D1/1487; B03D1/1493; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
114 words
In a method of de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, the improvement which comprises supplying the air-laden pulp suspension to the top region of a flotation cell, drawing off a portion of the accept in the form of purified pulp suspension from the bottom region of said flotation cell, and supplying an air-water suspension to said flotation cell in the region above the accept outlet and conducting said air-water suspension in the counterflow to the sinking accept fibers.
Claim 2
Dependent Claim
114 words
In a method of de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, the improvement which comprises supplying the air-laden pulp suspension to the top region of a flotation cell, drawing off a portion of the accept in the form of purified pulp suspension from the bottom region of said flotation cell, and supplying an air-water suspension to said flotation cell in the region above the accept outlet and conducting said air-water suspension in the counterflow to the sinking accept fibers.
Claim 3
Dependent Claim
16 words
Method according to claim 1 wherein said air-water suspension is accept which is conducted in circulation.
Claim 4
Dependent Claim
22 words
Method according to claim 1 or 2 wherein the returned amount of accept is between 10 and 150% of the total accept.
Claim 5
Dependent Claim
26 words
Method according to claim 1 or 2 wherein said air-laden pulp suspension is supplied to said flotation cell at several points distributed over the entire circumference.
Claim 6
Dependent Claim
39 words
Method according to claim 1 or 2 wherein the pulp is supplied to said flotation cell at an angle α of between 10° and 55° relative to the tangent to the circle of the cross-section of said flotation cell.
Claim 7
Dependent Claim
24 words
Method according to claim 1 or 2 wherein said air-water suspension is supplied at several points distributed over the circumference of said flotation cell.
Claim 8
Dependent Claim
40 words
Method according to claim 1 or 2 wherein said air-water suspension is injected into said flotation cell at an angle α of between 0° and 30° relative to the tangent and said pulp suspension is put into a circular motion.
Claim 9
Dependent Claim
77 words
Method according to claim 1 or 2 wherein in a divided flotation cell, said pulp suspension, rising from the bottom region of a first section, flows over a weir arranged between the first and the second sections, sinks downwardly in said second section and is drawn off from the bottom region, while, simultaneously, an air-water suspension is supplied in a counterflow and the foam accumulating on the surfaces of the suspension in both sections is drawn off.
Claim 10
Dependent Claim
110 words
Method according to claim 1 or 2 wherein in a divided flotation cell, said pulp suspension, rising from the bottom region of a first section, flows over a weir arranged between the first and the second sections, sinks downwardly in said second section and is drawn off from the bottom region, while, simultaneously, an air-water suspension is supplied in a counterflow and the foam accumulating on the surfaces of the suspension in both sections is drawn off and as said air-water suspension, a portion of the accept taken from said second section is returned, after a renewed foaming, to the bottom range of said second section above the accept outlet.
Claim 11
Dependent Claim
95 words
Method according to claim 1 or 2 wherein in a divided flotation cell, said pulp suspension, rising from the bottom region of a first section, flows over a weir arranged between the first and the second sections, sinks downwardly in said second section and is drawn off from the bottom region, while, simultaneously, an air-water suspension is supplied in a counterflow and the foam accumulating on the surfaces of the suspension in both sections is drawn off and said air-water suspension is supplied to said second section at several points distributed over the entire circumference.
Claim 12
Dependent Claim
197 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein in said annular flotation cell(1), (a) the inlet pipe or pipes (34) for said pulp suspension are arranged between 300 and 1000 mm below the level (6) of said pulp suspension, (b) the outlet pipe (35) is arranged approximately at the level of the bottom, (c) the after-aeration pipe or pipes (36) are arranged 300 to 500 mm above said outlet pipe (35) and 300-1700 mm below said inlet pipe or pipes(34), (d) said inlet pipes (34) and said after-aeration pipes (36) are directly connected to injectors (7,20), and (e) said injectors (7,20) are connected to ascending pipes (33) for drawing in air, said ascending pipes (33) being transparent at least in the immediate region of said nozzles (7,20).
Claim 13
Dependent Claim
197 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein in said annular flotation cell(1), (a) the inlet pipe or pipes (34) for said pulp suspension are arranged between 300 and 1000 mm below the level (6) of said pulp suspension, (b) the outlet pipe (35) is arranged approximately at the level of the bottom, (c) the after-aeration pipe or pipes (36) are arranged 300 to 500 mm above said outlet pipe (35) and 300-1700 mm below said inlet pipe or pipes(34), (d) said inlet pipes (34) and said after-aeration pipes (36) are directly connected to injectors (7,20), and (e) said injectors (7,20) are connected to ascending pipes (33) for drawing in air, said ascending pipes (33) being transparent at least in the immediate region of said nozzles (7,20).
Claim 14
Dependent Claim
168 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein in said annular flotation cell (1), (a) the inlet pipe or pipes (34) for said pulp suspension are arranged between 300 and 1000 mm below the level (6) of said pulp suspension, (b) the outlet pipe (35) is arranged approximately at the level of the bottom, (c) the after-aeration pipe or pipes (36) are arranged 300 to 500 mm above said outlet pipe (35) and 300-1700 mm below said inlet pipe or pipes (34), and (d) ascending pipes (33) extend above the filling level of said annular flotation cell (1).
Claim 15
Dependent Claim
168 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein in said annular flotation cell (1), (a) the inlet pipe or pipes (34) for said pulp suspension are arranged between 300 and 1000 mm below the level (6) of said pulp suspension, (b) the outlet pipe (35) is arranged approximately at the level of the bottom, (c) the after-aeration pipe or pipes (36) are arranged 300 to 500 mm above said outlet pipe (35) and 300-1700 mm below said inlet pipe or pipes (34), and (d) ascending pipes (33) extend above the filling level of said annular flotation cell (1).
Claim 16
Dependent Claim
157 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, comprising two annular cells (2, 3) which are arranged essentially concentrically relative to each other and are separated from each other by a weir (24) which facilitates the overflow of pulp suspensions from said first annular cell (2) into said second annular cell (3), and by connections for introducing air-laden pulp suspension at said first annular cell (2), an accept outlet (25) in the bottom region of said second annular cell (3), at least one connection for supplying an additional air-water suspension above said accept outlet (25) of said second annular cell (3) and a device for drawing off the accumulating dirt-laden foam in the top region of both annular cells (2, 3).
Claim 17
Dependent Claim
157 words
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, comprising two annular cells (2, 3) which are arranged essentially concentrically relative to each other and are separated from each other by a weir (24) which facilitates the overflow of pulp suspensions from said first annular cell (2) into said second annular cell (3), and by connections for introducing air-laden pulp suspension at said first annular cell (2), an accept outlet (25) in the bottom region of said second annular cell (3), at least one connection for supplying an additional air-water suspension above said accept outlet (25) of said second annular cell (3) and a device for drawing off the accumulating dirt-laden foam in the top region of both annular cells (2, 3).
Claim 18
Dependent Claim
45 words
Arrangement according to claim 13 wherein said accept outlet (25) is composed of an overflow (9) which is connected at the bottom region of said second annular cell (3) and, outside of said annular cell (3), extends essentially to the level of said weir (24).
Claim 19
Dependent Claim
36 words
Arrangement according to claim 13 or 14 wherein said weir (24) between said first annular cell (2) and said second annular cell (3) is 30 to 150 mm below the level (6) of said pulp suspension.
Claim 20
Dependent Claim
35 words
Arrangement according to claim 13 or 14 wherein said connection or connections for supplying said additional air-water suspension into said second annular cell (3) are arranged 100 to 300 mm above said accept outlet (25).
Claim 21
Dependent Claim
47 words
Arrangement according to claim 13 or 14 wherein said first annular cell (2) to which said pulp suspension is admitted in uniflow forms the inner annular cell and said second annular cell (3) to which said pulp suspension is admitted in counterflow forms the outer annular cell.
Claim 22
Dependent Claim
62 words
Arrangement according to claim 13 or 14 wherein said injectors (7,20) for supplying said pulp suspension to said first annular cell (2) and said second annular cell (3) are arranged at an angle of between 0° and 30° relative to the tangent, wherein said injectors (7,20), at least in one annular cell (2,3), are arranged at different angles relative to one another.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |