CA1335147C - System for wastepaper conditioning - Google Patents
System for wastepaper conditioningInfo
- Publication number
- CA1335147C CA1335147C CA 604656 CA604656A CA1335147C CA 1335147 C CA1335147 C CA 1335147C CA 604656 CA604656 CA 604656 CA 604656 A CA604656 A CA 604656A CA 1335147 C CA1335147 C CA 1335147C
- Authority
- CA
- Canada
- Prior art keywords
- flotation
- stage
- level
- turbulence
- deckering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
- D21C5/02—Working-up waste paper
- D21C5/025—De-inking
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
- B03D1/00—Flotation
- B03D1/02—Froth-flotation processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Landscapes
- Paper (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
The wastepaper conditioning system features in the main circuit two different flotation systems whose design in terms of air supply and mixing is adapted to the various particles to be removed by flotation, as regards their floatability (size or hydrophobia). This makes it possible to achieve a better degree of dirt separation in wastepaper that is to be deinked.
Description
1 3 ~ 7 SYSTEM FOR WASTEPAPER CONDITIONING
The invention concerns a system for wastepaper conditioning (deinking) of wastepaper with several successively arranged cleaning stages of which one comprises a multiple stage flotation system, also through direct sequential arrangement of individual flotation cells, and where a further separation of dirt takes place in another flotation system. Such a system is known from the German Patent Disclosure 28 13 448.
In this system, the deckering water accruing in the concentrator is selectively cleaned of the dirt it carries in another flotation system.
Similarly, according to "Wochenblatt fur Papierfabrikation"
1976, page 780, wash filtrate of a system for wastepaper conditioning is clarified in so-called flotation substance catchers using the flotation principle. These flotation apparatuses, for instance pursuant to "Da~ Papier", 1975, page V 159, operate practically without turbulence so that all floating substances contained in the wash filtrate are being separated, for one downwardly by sedimentation and for another upwardly by flotation. All that remains in the filtrate is practically only a very small, negligible portion of these.
In this way, the clarified wash filtrate can be recycled in the circuit as wash water. This is a relatively commonplace measure, since wasting water through unnecessarily high water consumption must be avoided, whereas on the other hand also relatively clean water is to be used for washing. A similar system is knows also from ~'Paper Technology", pages 282-283.
. r ~ ~ -2- 1 3351 47 The problem underlying the invention is to improve by flotation the dirt separation in the wastepaper suspension, that is, in the major circuit. This problem is inventionally solved by the features of the present invention.
Suitable as first ~otation stage is especially a flotation cell equipped with at the most a few large injectors, for instance, according to the German Patent Disclosure 31 44 387 (published May 19, 1983). Suitable for the flotation setup of the second flotation process stage are cells with a dispersing wheel according to U.S. Patent No. 4,267,052 or flotation cells with very many injectors using the design according to British Patent Application 2,042,788 (published September 17, 1980). It yields a relatively small bubble size at a relatively low ratio of air quantity to suspension quantity.
Dividing the flotation in at least two processing stages accomplishes that a maxin~ separation of the substances to be removed by flotation can take place in accordance with their characteristic flotation features. Relatively large dirt is separated best by a ~otation of great turbulence and with large air bubble diameters while relatively small dirt or such with low hydrophobia is separated best by a flotation with little turbulence.
The invention will be explained hereafter with the aid of embodiments illustrated in the drawings.
Fig. 1 is a schematic diagram of a wastepaper conditioning system in accordance with the present invention.
Fig. 2 is a schematic diagram of another embodiment of a wastepaper t'~ conditioning system.
1~
_3_ l 335 1 47 Illustrated in Fig. l i~ a dual ~tage flotation, where A
means dissolution, V presorting, F I thQ flotation proc~ss stage I with high turbulence, which may comprise also multiple stages, F fine cleaning, 5 sorting, F II the flotation process stage II with relatively little turbulence and very fine air bubbles, which may comprise also multiple stages, and E a deckering stage. These abbreviations apply also to Fig. 2.
These treatment steps are arranged in the main circuit, with a side circuit indicated by broken line that contains a third type F III flotation stage with a very calmed flotation, for instance clarification flotation, that can be likened to a sedimentation and by which filtrate water of the deckering stage can be cleaned further. A relatively large amount of air is used in the flotation stage F I, so that the ratio of air amount L to the total weight of suspension G, based on dry substance (otro), meets the following condition: 30 ~ L/G ~ 100%
The air bubble size should be so selected that at least 80% of these will be greater than 1 mm in diameter. Considerably smaller air bubbles and also a considerably smaller quantity of air, according to the condition ~/G ~ 30~, are used in the flotation stage F II. The air bubble si2e should be so selected that at least 60~ of these will be less than 1 mm in diameter, and more preferably at least 80t will be les3 than 1 mm in diameter. Indicated additionally, by arrows C, C' and C'', is the addition of chemicals for the various process steps. The broken-line arrows mean the addition of water.
The cleaning and sorting stages V, F and S are consistent with those of usual systems, such as following, e.g., from the mentioned "Paper Technology", page 282, Fig. 1, and from the German Patent Publication 26 10 581, Fig. 1.
_4_ 1 335 1 47 In the system according to Fig. 2, the deckering E
including a di~per~ion apparatu~ D is arranged before the flotation stage F II. Provided after the flotation stage F II
is a second deckering stage that is accompanied by a bleaching B. The wastewater of both deckering stages is cleaned as well by a flotation stage F III. Here, too, the flotation stage F
III is of the type of the same stage relative to Fig. 1.
Instead of discarding the flotation rejects from stage F
II, they may be recycled also to the first flotation stage F I
according to the double dot/dash line.
_ -
The invention concerns a system for wastepaper conditioning (deinking) of wastepaper with several successively arranged cleaning stages of which one comprises a multiple stage flotation system, also through direct sequential arrangement of individual flotation cells, and where a further separation of dirt takes place in another flotation system. Such a system is known from the German Patent Disclosure 28 13 448.
In this system, the deckering water accruing in the concentrator is selectively cleaned of the dirt it carries in another flotation system.
Similarly, according to "Wochenblatt fur Papierfabrikation"
1976, page 780, wash filtrate of a system for wastepaper conditioning is clarified in so-called flotation substance catchers using the flotation principle. These flotation apparatuses, for instance pursuant to "Da~ Papier", 1975, page V 159, operate practically without turbulence so that all floating substances contained in the wash filtrate are being separated, for one downwardly by sedimentation and for another upwardly by flotation. All that remains in the filtrate is practically only a very small, negligible portion of these.
In this way, the clarified wash filtrate can be recycled in the circuit as wash water. This is a relatively commonplace measure, since wasting water through unnecessarily high water consumption must be avoided, whereas on the other hand also relatively clean water is to be used for washing. A similar system is knows also from ~'Paper Technology", pages 282-283.
. r ~ ~ -2- 1 3351 47 The problem underlying the invention is to improve by flotation the dirt separation in the wastepaper suspension, that is, in the major circuit. This problem is inventionally solved by the features of the present invention.
Suitable as first ~otation stage is especially a flotation cell equipped with at the most a few large injectors, for instance, according to the German Patent Disclosure 31 44 387 (published May 19, 1983). Suitable for the flotation setup of the second flotation process stage are cells with a dispersing wheel according to U.S. Patent No. 4,267,052 or flotation cells with very many injectors using the design according to British Patent Application 2,042,788 (published September 17, 1980). It yields a relatively small bubble size at a relatively low ratio of air quantity to suspension quantity.
Dividing the flotation in at least two processing stages accomplishes that a maxin~ separation of the substances to be removed by flotation can take place in accordance with their characteristic flotation features. Relatively large dirt is separated best by a ~otation of great turbulence and with large air bubble diameters while relatively small dirt or such with low hydrophobia is separated best by a flotation with little turbulence.
The invention will be explained hereafter with the aid of embodiments illustrated in the drawings.
Fig. 1 is a schematic diagram of a wastepaper conditioning system in accordance with the present invention.
Fig. 2 is a schematic diagram of another embodiment of a wastepaper t'~ conditioning system.
1~
_3_ l 335 1 47 Illustrated in Fig. l i~ a dual ~tage flotation, where A
means dissolution, V presorting, F I thQ flotation proc~ss stage I with high turbulence, which may comprise also multiple stages, F fine cleaning, 5 sorting, F II the flotation process stage II with relatively little turbulence and very fine air bubbles, which may comprise also multiple stages, and E a deckering stage. These abbreviations apply also to Fig. 2.
These treatment steps are arranged in the main circuit, with a side circuit indicated by broken line that contains a third type F III flotation stage with a very calmed flotation, for instance clarification flotation, that can be likened to a sedimentation and by which filtrate water of the deckering stage can be cleaned further. A relatively large amount of air is used in the flotation stage F I, so that the ratio of air amount L to the total weight of suspension G, based on dry substance (otro), meets the following condition: 30 ~ L/G ~ 100%
The air bubble size should be so selected that at least 80% of these will be greater than 1 mm in diameter. Considerably smaller air bubbles and also a considerably smaller quantity of air, according to the condition ~/G ~ 30~, are used in the flotation stage F II. The air bubble si2e should be so selected that at least 60~ of these will be less than 1 mm in diameter, and more preferably at least 80t will be les3 than 1 mm in diameter. Indicated additionally, by arrows C, C' and C'', is the addition of chemicals for the various process steps. The broken-line arrows mean the addition of water.
The cleaning and sorting stages V, F and S are consistent with those of usual systems, such as following, e.g., from the mentioned "Paper Technology", page 282, Fig. 1, and from the German Patent Publication 26 10 581, Fig. 1.
_4_ 1 335 1 47 In the system according to Fig. 2, the deckering E
including a di~per~ion apparatu~ D is arranged before the flotation stage F II. Provided after the flotation stage F II
is a second deckering stage that is accompanied by a bleaching B. The wastewater of both deckering stages is cleaned as well by a flotation stage F III. Here, too, the flotation stage F
III is of the type of the same stage relative to Fig. 1.
Instead of discarding the flotation rejects from stage F
II, they may be recycled also to the first flotation stage F I
according to the double dot/dash line.
_ -
Claims (20)
1. System for conditioning wastepaper comprising:
a main circuit including sequentially arranged first and second flotation systems each operating with turbulence, the first flotation system operating at a level of turbulence greatly exceeding that of the second flotation system, the first flotation system operating with a ratio of air L to dry weight of suspension G such that 0.3 ? L/G ? 1.0, the second flotation system operating at low turbulence just above that level at which fiber flotation occur and with a ratio of air L to dry weight of suspension G such that LG ? 0.3.
a main circuit including sequentially arranged first and second flotation systems each operating with turbulence, the first flotation system operating at a level of turbulence greatly exceeding that of the second flotation system, the first flotation system operating with a ratio of air L to dry weight of suspension G such that 0.3 ? L/G ? 1.0, the second flotation system operating at low turbulence just above that level at which fiber flotation occur and with a ratio of air L to dry weight of suspension G such that LG ? 0.3.
2. The system of claim 1, in which the first flotation system includes multiple like flotation stages.
3. The system of claim 1, in which the second flotation system includes multiple like flotation stages.
4. The system of claim 1, in which each of the first and second flotation systems includes multiple like flotation stages.
5. System according to claim 1, and further including a deckering stage and a third flotation system operating at low turbulence just above that level at which fiber flotation occurs for receiving and cleaning wastewater from said deckering stage.
6. System according to claim 1, in which the second flotation system has an air bubble distribution in which at least 60% of air bubbles have a diameter less than about 1 mm.
7. System according to claim 1, in which the second flotation system has an air bubble distribution in which at least 80% of air bubbles have a diameter less than about 1 mm.
8. System according to claim 3, and further including a deckering stage and a third flotation system operating at low turbulence just above that level at which fiber flotation occurs for receiving and cleaning wastewater from said deckering stage.
9. System according to claim 3, in which the second flotation system has an air bubble distribution in which at least 60% of air bubbles have a diameter less than about 1 mm.
10. System according to claim 3, in which the second flotation system has an air bubble distribution in which at least 80% of air bubbles have a diameter less than about 1 mm.
11. The system of Claim 1, in which the first flotation system operates at a level of turbulence at least 1.5 times the level of turbulence of the second flotation system.
12. The system of Claim 1, in which the first flotation system operates at a level of turbulence at least 2 times the level of turbulence of the second flotation system.
13. A method of conditioning wastepaper comprising the steps of passing said wastepaper through a first flotation system operating at a predetermined level of turbulence with a ratio of air L to dry weight of suspension G such that 0.3 ? L/G ? 1.0, subsequently passing said wastepaper through a second flotation system operating with a level of turbulence significantly less than said predetermined level and just above that level at which fiber flotation occurs and with a ratio of air L to dry weight of suspension G such that L/G ? 0.3.
14. A method according to claim 13 including the step of passing said wastepaper through a first deckering stage between said first and second stages.
15. A method according to claim 14 including the step of passing said wastepaper through a deckering stage located after said second stage.
16. A method according to claim 14 or 15 including the step of dispersing said wastepaper in said first deckering stage.
17. A method according to claim 15 including the step of bleaching in said second deckering stage.
18. A method according to claim 14 or 15 in which wastewater from at least one deckering stage passes through a third flotation stage.
19. A method according to claim 14 or 15 in which wastewater from at least one deckering stage passes through a third flotation stage operating at a level of turbulence just above that level at which fiber flotation occurs.
20. A method according to claim 14 or 15 in which wastewater from said second filtration stage is recycled to said first flotation stage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3822454.2 | 1988-07-02 | ||
| DE3822454A DE3822454C1 (en) | 1988-07-02 | 1988-07-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1335147C true CA1335147C (en) | 1995-04-11 |
Family
ID=6357834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 604656 Expired - Fee Related CA1335147C (en) | 1988-07-02 | 1989-07-04 | System for wastepaper conditioning |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0349806B1 (en) |
| JP (1) | JPH0247381A (en) |
| AT (1) | ATE111985T1 (en) |
| CA (1) | CA1335147C (en) |
| DE (1) | DE3822454C1 (en) |
| ES (1) | ES2058398T3 (en) |
| NO (1) | NO174721C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5770050A (en) * | 1994-07-22 | 1998-06-23 | Voith Sulzer Stoffaufbereitung Gmbh | Flotation apparatus |
| US7267231B2 (en) * | 2003-02-25 | 2007-09-11 | Andritz Ag | Process and device for aerating suspensions |
| DE102015000359A1 (en) | 2015-01-20 | 2016-07-21 | Stora Enso Sachsen GmbH | Plant and deinking process |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4113861A1 (en) * | 1991-04-27 | 1992-10-29 | Gat Handelsgesellschaft Fuer I | Device for cleaning waste layer from printing operations - consists of storage vessel linked to reaction vessel by transfer pump with level switches in reaction vessel control agitator, filling, emptying and reagent dosing |
| DE102004020339A1 (en) * | 2004-04-26 | 2005-11-10 | Voith Paper Patent Gmbh | Process for flotation of contaminants from an aqueous paper fiber suspension |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1177465B (en) * | 1959-03-12 | 1964-09-03 | Voith Gmbh J M | Flotation machine |
| DE2511435B2 (en) * | 1975-03-12 | 1977-02-03 | Flotiervorrichtung Escher Wyss GmbH, 7980 Ravensburg | Waste paper pulp cleaning device - having porous base which is selectively covered by strips to control flow of air adjacent foam removing troughs |
| DE2813448B1 (en) * | 1978-03-29 | 1978-09-21 | Voith Gmbh J M | Process and plant for recycling waste paper |
| GB2041788B (en) * | 1978-08-21 | 1982-10-06 | Feldmuehle Ag | Method and device for cleaning suspension fibres |
| DE2904326C3 (en) * | 1979-02-05 | 1982-05-13 | Naamloze Vennootschap Papierfabriek Gennep, Gennep | Process and device for deinking pulp suspensions |
| US4267052A (en) * | 1979-12-10 | 1981-05-12 | Chang Shih Chih | Aeration method and apparatus |
| CH665962A5 (en) * | 1985-07-19 | 1988-06-30 | Escher Wyss Gmbh | GASIFICATION DEVICE FOR A FLOTATION DEVICE AND ITS USE. |
| DE3634903A1 (en) * | 1986-10-14 | 1988-04-28 | Voith Gmbh J M | Flotation device |
-
1988
- 1988-07-02 DE DE3822454A patent/DE3822454C1/de not_active Expired
-
1989
- 1989-06-16 EP EP89110963A patent/EP0349806B1/en not_active Expired - Lifetime
- 1989-06-16 AT AT89110963T patent/ATE111985T1/en active
- 1989-06-16 ES ES89110963T patent/ES2058398T3/en not_active Expired - Lifetime
- 1989-06-29 JP JP1165505A patent/JPH0247381A/en active Pending
- 1989-06-30 NO NO892725A patent/NO174721C/en unknown
- 1989-07-04 CA CA 604656 patent/CA1335147C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5770050A (en) * | 1994-07-22 | 1998-06-23 | Voith Sulzer Stoffaufbereitung Gmbh | Flotation apparatus |
| US7267231B2 (en) * | 2003-02-25 | 2007-09-11 | Andritz Ag | Process and device for aerating suspensions |
| DE102015000359A1 (en) | 2015-01-20 | 2016-07-21 | Stora Enso Sachsen GmbH | Plant and deinking process |
| WO2016116802A1 (en) | 2015-01-20 | 2016-07-28 | Stora Enso Sachsen GmbH | Plantlayout and deinking method |
| CN107250457A (en) * | 2015-01-20 | 2017-10-13 | 罗曼·克劳泽 | Equipment is arranged and de-inking method |
| CN107250457B (en) * | 2015-01-20 | 2020-11-13 | 罗曼·克劳泽 | Equipment arrangement and deinking method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0247381A (en) | 1990-02-16 |
| EP0349806B1 (en) | 1994-09-21 |
| ES2058398T3 (en) | 1994-11-01 |
| EP0349806A3 (en) | 1991-07-31 |
| NO892725D0 (en) | 1989-06-30 |
| NO174721B (en) | 1994-03-14 |
| NO174721C (en) | 1994-06-22 |
| ATE111985T1 (en) | 1994-10-15 |
| NO892725L (en) | 1990-01-03 |
| EP0349806A2 (en) | 1990-01-10 |
| DE3822454C1 (en) | 1989-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| FI85037B (en) | FOERFARANDE OCH ANORDNING FOER BEHANDLING AV AVFALLSTRYCKPAPPER. | |
| EP1728918A2 (en) | Proces for removing impurities from an aqueous fibrous suspension | |
| KR900004943B1 (en) | A waste paper preparation system | |
| GB2231595A (en) | De-inking waste printed paper using enzymes | |
| PL246957A1 (en) | Method of decolorization of pulp or suspension and apparatus therefor | |
| EP0537416B1 (en) | Process for the treatment of pulp | |
| US6416622B2 (en) | Hybrid multistage forward cleaner system with flotation cell | |
| Kemper | State-of-the-art and new technologies in flotation deinking | |
| US5358605A (en) | Process for recycling waste paper | |
| CA1335147C (en) | System for wastepaper conditioning | |
| US6277239B1 (en) | Process for removing fine impurities from a fibrous suspension | |
| US7296682B2 (en) | Process for controlling operation of a flotation cell | |
| US4368101A (en) | Method and apparatus for the production of a suspension of fibrous material made from waste-paper | |
| ATE32112T1 (en) | ARRANGEMENT FOR THE TREATMENT OF WASTE PAPER. | |
| US6183595B1 (en) | Process for treating a fibrous material suspension using combination of low-intensity and high-intensity flotation | |
| DE10256519A1 (en) | Process to remove printing ink from recycled paper by selective floatation and separation of fibers into coarse and fine fractions | |
| US7267231B2 (en) | Process and device for aerating suspensions | |
| CN106948199A (en) | The system that a kind of use floatation handles waste paper pulp sicker | |
| EP0233517A3 (en) | Process and apparatus for deinking paper pulp obtained from waste paper | |
| EP1591583A1 (en) | Process for removing impurities by flotation from an aqueous fibrous suspension | |
| EP0187909B1 (en) | Process and apparatus for eliminating impurities from a waste paper suspension | |
| EP0398846A2 (en) | Deinking apparatus in the constant density section of paper manufacturing plants | |
| WO1999002770A1 (en) | Use of cationic polyelectrolytes and surfactants in the deinking of wastepaper | |
| CA2032256A1 (en) | Biological Method of Deinking Printed Wastepaper | |
| DE69415035D1 (en) | METHOD AND DEVICE FOR DRAINING A FIBER FIBER SUSPENSION |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |