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(11) | EP 1 010 804 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Method and apparatus for treating broke Verfahren und Vorrichtung zur Behandlung von Ausschuss Procédé et dispositif pour le traitement des cassés |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present invention relates to a method of and apparatus for treating broke. Especially the invention relates to treating broke coming from a paper and/or paperboard machine so that the pulp may be metered back to said machine in a way which is more preferable than prior art methods in view of both paper and/or paperboard manufacture and environmental aspects.
[0002] The word broke refers to waste material generated by a paper, paperboard or the like machine in some stage of the production process. Broke is generated continuously in the so-called edge cutting where the paper or paperboard web produced by the paper or paperboard machine is cut to the desired width, i.e. at both sides of the web a strip of essentially finished product is cut off. In addition to that, broke is generated during process breaks caused by various reasons, whereby the whole production of the production machine has to be diverted to the broke system. Broke is also generated by the winder, and sometimes even whole paper or paperboard rolls are damaged when still in the mill so that they have to be returned to reuse through the broke system. In other words, the water content of broke varies to a remarkable extent according to the generation point of the broke. In the beginning stage of the process, e.g. on the wire part of the paper machine, the broke may well be said to have a consistency, whereby the broke is often referred to as so-called wet broke, but broke obtained after the press section is already in most cases referred to as so-called dry broke. And especially when whole paper rolls are diverted to broke, the product practically corresponds to dry finished product.
[0003] In a conventional broke system, the broke is stored in a consistency of about 3 - 4 %. Such a low consistency requires huge buffer tanks for the paper or paperboard machine for the process waters, because breaks in the production process and sometimes long discontinuous process stages must be prepared for beforehand. In such a case, the broke system has to be able to receive all paper or paperboard produced by the machine either as such, whereby the broke is wet broke being collected in the couch pit or, in case of dry broke, through broke pulpers or the like utilizing process waters in the slushing. Said big buffer tanks increase the time needed for changes of grade and complicate the regulation of the process. In this connection it is worth mentioning that the dimensions of said broke and water containers of big production machines are typically in the order of thousands of cubic meters. As an example it may be stated that when the production of a paper machine is e.g. 700 t/d, the size of both the dilution water tank and the broke tank is about 5000 m3.
[0004] In addition to space requirements and big investments, these large containers cause problems due to relatively slow water circulations creating advantageous conditions for the forming of various slime and microbe growths. And further, due to large amount of process water needed, the only possibility is actually the use of white water generated in the mill in a sufficient amount. Otherwise it would be necessary to use fresh water from watercourses, the use of which is out of order nowadays. Nevertheless, said white water is a good culture medium for said slime and microbe growths. One more problem worth mentioning is that prior art broke systems have not been capable of removing from the pulp the undesired materials introduced to the pulp with the broke, said undesired materials being various microbes, resins, colloidal materials, starches, paper binding agents and other materials disturbing practically the whole process or at least the functioning of a part of it, but these have gone into the production process with the result of decreased quality of the finished product.
[0005] DE-A-195 32 301 discloses a method and an apparatus for treating broke obtained from a paper, paperboard or coating machine. Diluted broke is fed, in sequence, to a pulper, a heavy particle separator, a contamination sorting device and a destipper. The thus processed broke is then fed to a thickening device, such as a press, and subsequently to a storage container.
[0006] Figure 1 illustrates a prior art broke system for treating dry broke and comprising a broke pulper, a dilution liquid tank, an intermediate tank, a press, a storage container and pumps required by the process. This prior art broke system operates so that dry broke is introduced into one of several pulpers in the paper machine and diluted during the slushing to an appropriate consistency with white water obtained from the dilution liquid tank. The slushed broke is taken by means of a pump into the intermediate tank in form of a dilute, most usually 2 - 4 %, suspension. From the intermediate tank the dilute broke suspension is lead by means of a pump into the press, with which press the consistency of the broke is raised into storage consistency, usually in the order of 10 - 20 %. The press filtrate is typically removed from the process.
[0007] This kind of prior art broke system treating dry broke typically operates so that the intermediate tank is dimensioned to .receive all possible low consistency broke that can be thought to be generated from the paper machine, in other words the whole production of the paper mill during some predetermined period of time. Thus, it is clear that also the dilution liquid tank has to be dimensioned to store all the liquid required for diluting the maximum amount of broke being generated. A further characterizing feature of this prior art process is that the press is dimensioned for treating broke practically on a continuous basis. One of the dimensioning principles is that the press must be capable of treating about 15 - 20 % of the maximum production of the paper machine. That is, the pulpers are dimensioned to defiberize the dry broke quickly to a dilute consistency to be taken into the intermediate tank performing the function of a buffer tank for the continuously operating press.
[0008] To solve said problems, among others, a new type of method and apparatus for treating dry broke has been developed. The method and apparatus for treating pulp broke according to one preferred embodiment of the invention are characterized, e.g., in that the dry broke is thickened immediately after defiberizing, most commonly slushing performed with a pulper, by means of an applicable thickening device, preferably a press, to a suitable consistency which may be preferably 20 - 35 %, more preferably 25 - 30 % (when thinking more widely, the consistency may vary even in the range of 12 - 45 %, considering all different situations and pulp grades) and stored in said consistency. The broke is stored e.g. in a HC-silo provided with a diluting scraper at the bottom. As an example it may be mentioned that with a paper machine production of 700 t/d, a press capable of producing 700 t/d only and a storage container of about 500 m3 only are required.
[0009] To put it differently, when a prior art broke treating system requires two storage containers of about 5000 cubic meters (one for low consistency broke and the other for the white water used as dilution liquid), one relatively small press and one HC-storage tower, the system according to our invention requires one thickening device of relatively big size, preferably a press, one HC-storage tower and a small dilution liquid tank, the size of which is about one quarter of the older one.
[0010] The method and apparatus for treating dry broke according to another preferred embodiment of the invention are further characterized in that the filtrate removed from the defiberized pulp by means of a thickening device, preferably a press, is guided back during production break to be used as dilution water in the dry broke defiberizer.
[0011] The method and apparatus according to a third preferred embodiment of the invention are characterized in that in a normal running situation the filtrate of the thickening device, preferably a press, is lead to a suitable separation device in order to remove undesired materials and impurities and further taken into the white water treatment system.
[0012] Other characterizing features of the method and apparatus according to the invention are disclosed in the appended patent claims.
[0013] As advantages of the method and apparatus according to the invention, the following may be mentioned, among others:
- by storing the pulp in high consistency only and thus leaving out-containers causing long delays, the water circulations are intensified, thus preventing the generation of conditions favorable for slime and microbe growths,
- the size of the circulation water containers is essentially decreased, as water absorbed in the broke during the defiberizing of dry broke is immediately removed from the broke and returned into the defiberizer for diluting the broke,
- storing the defiberized broke at a high consistency decreases the size of the broke tank to a fractional part of dimensions needed nowadays (including both the low-consistency intermediate tank and the HC -storage container),
- by treating the filtrate leaving the press by means of an appropriate separating technique, the undesired materials coming with the broke may be removed from the process,
- because the water amount required for the process is essentially decreased, water being stored for dilution may be e.g. clear filtrate from a disc filter instead of white water only, which is preferable for preventing slime and microbe growths.
[0014] In the following, the method and apparatus according to the invention are explained in more detail with reference to the appended figures, of which
Fig. 1 illustrates a prior art broke system for treating dry broke,
Fig. 2 illustrates a broke system for treating dry broke according to a preferred embodiment of the invention, and
Fig. 3 illustrates a broke system for treating dry broke according to another preferred embodiment of the invention.
[0015] The broke system of Fig. 1 for treating dry broke comprises a broke pulper 10, a dilution liquid tank 12, an intermediate tank 14, a press 16, a storage container 18 and pumps 20 and 22 required by the process. This broke system according to prior art operates so that dry broke is introduced to one of several pulpers 10 of the paper machine, and diluted during the slushing into a suitable consistency with white water obtained from the dilution liquid tank 12. The broke slushed in the pulper 10 is taken by means of pump 20 to the intermediate tank 14 in form of a dilute suspension, most usually 2 - 4 %. From the intermediate tank the dilute broke suspension is taken by means of pump 22 to press 16, by means of which the consistency of the broke is raised to storage consistency, usually in the order of 10 - 20 %. The filtrate of the press is typically removed from the process.
[0016] The broke system for treating dry broke according to Fig. 1 typically operates so that the intermediate tank 14 is dimensioned to receive all possible low-consistency broke that may be considered to originate from the paper machine. Thus it is clear that also the dilution liquid tank 12 has to be dimensioned to receive the whole amount of liquid needed to dilute the dry broke in this kind of situation when broke is originated in maximum amount. The process is further characterized in that the press 16 is dimensioned to treat the broke practically on a continuous basis. One principle of dimensioning is that the press must be capable of treating about 15 - 20 % of the maximum production of the paper machine. In other words, the pulpers 10 are dimensioned to disintegrate the dry broke quickly to a dilute consistency to be taken into the intermediate tank functioning as a buffer tank for the continuousty operating press.
[0017] Fig. 2 is a schematic illustration of a broke system for treating dry broke according to a preferred embodiment of the invention, in which the broke obtained in a dilute consistency from the defiberizer 10, preferably a pulper/pulpers, is lead in all different running situations in the mill directly to a thickening device 36, preferably a press, by means of which the consistency of the broke is raised to HC-range, considering all different situations of use and all grades of pulp to a consistency of 12 - 45 %, preferably to a consistency of 20 - 35 %, more preferably to a consistency of 25 - 30 %, and from which the filtrate is immediately returned back to function as dilution liquid of the defiberizer 10. In accordance with the invention the described system is applicable to the treatment of continuously originating broke such as e.g. trimmings and the maximum amount of broke originating during breaks. According to an alternative embodiment of the invention, the filtrate recirculation illustrated in Fig. 2 is utilized only during web breaks, whereby both the defiberizer and the thickening device must be capable of treating the maximum amount of broke. In that case, there is also the biggest need for dilution liquid, so that by recirculating the dilution liquid it is possible to avoid using big dilution liquid buffer tanks. Only at the initial stage of the defiberizing, dilution liquid obtained from another source 32 is needed. Immediately as the thickening, preferably pressing, following the defibrizing starts functioning, essentially all dilution liquid needed in the defiberizing of the dry broke is obtained from the thickening device, preferably a press 36, the filtrate of which is collected, schematically illustrated into a reservoir 40, and taken by means of a pump 42 via pipe line 44 to the defiberizer 10, preferably a pulper.
[0018] Fig. 3 illustrates a broke system for treating dry broke according to another preferred embodiment of the invention, which system describes the liquid circulation of the process better than the system of Fig. 2. In the process according to Fig. 3, operating like the process of Fig. 2 in view of the defiberizing and thickening of the broke, white water obtained from tank 52 is presented to be used not only for diluting the thickened and defiberized broke fed from the press 36 by means of a feeding apparatus into the HC-container 38 and stored in HC-consistency, but also for diluting the broke during the defiberizing. However, this has been arranged so that the white water from tank 52 is circulated through a fiber-recovery filter 54, preferably a disc filter, where an essential part of solid matter may be removed from the water so that clear filtrate from reservoir 56 is used for diluting the dry broke. The same is planned to be done also when filtrate is removed from the press 36. Filtrate line 48 coming from the press 36 is provided with a separation device 50 for removing undesired material from the filtrate, after which the cleaned filtrate is guided into reservoir 58 for the turbid filtrate of the fiber-recovery filter 54, which turbid filtrate is returned back to the feed of filter 54. And again, from the filter, the clear filtrate obtained from reservoir 56 is guided into its own reservoir 32, which reservoir provides the defiberizer 10 with dilution liquid. In principle, the process of Fig. 3 allows for the following two running possibilities. Firstly, it is possible to treat the filtrate of the thickening device 36 with the separation means for the undesired material 50 and the white water filter 54 in every running situation of the defiberizer 10 and the thickening device 36, although, in consideration of possible breaks, the system should be prepared to treat large amounts of liquid quickly with the separation means 50 and the white water filter 54. In principle, this kind of use is not impossible, though, and, accordingly, is not to be excluded from the scope of protection of the invention. The second running possibility is to circulate the filtrate of the thickening device through the separation means 50 and the white water filter 54 only when the defiberizer 10 and the thickening device are subjected to a constant load i.e. to evenly running constant-flow broke, as, e.g., in the defiberizing of the trimmings. In such a case, the dimensioning of both the separation means 50 and the white water filter 54 is simple, thanks to constant loads. In other words, during peak loads the filtrate of the thickening device may be guided directly through pipeline 44 to the defiberizer 10 without treating with the separation device and the white water filter. Peak loads, during which the filtrate of the thickening device 36 is needed to be guided directly to the defiberizer 10, occur, in addition to web breaks, e.g. in situations when the broke entering the defiberizer is relatively dry, i.e. broke coming from the final stage of paper or paperboard manufacture where the most part of liquid has been removed from the product.
[0019] A further possible method is an arrangement wherein there is a separate separation device for undesired material for treating the filtrate of the thickening device and a treatment apparatus for the filtrate for big loads, i.e. for web breaks or for treating dry broke, so that it would be possible to always clean all the filtrate obtained from the thickening device prior to returning it back to the pulper. In view of process purity this kind of arrangement is naturally the most optimal, but naturally it requires investments, compared to the arrangements of Fig. 2 and 3 in which the existing apparatus of the mill is being utilized whenever possible.
[0020] As already stated in a number of contexts in the description above, in the method according to the invention it is preferable to use a press as the thickening device, because many modem presses are capable of producing a consistency of the desired 25 - 35 %, and when using appropriate pulp grades and/or applicable presses even a consistency of 45 %, although said consistency range is by no means inevitable. As the press, e.g. a drum press described for instance in FI patents 84397 and 88435 may be utilized.
[0021] As noticed from the above, a new kind of method and apparatus for treating broke has been developed. The method and apparatus according to the invention eliminate many disadvantages of prior art apparatus and methods, thus simplifying the process and its runnability and allowing for more economical paper production and better quality of paper. Nevertheless, one has to notice that only a few preferred embodiments of the invention have been described above without any intention to limit the appended patent claims to said examples only. Thus, it is clear, e.g., that a press is not the only possible thickening device, but other kinds of thickening devices, such as screws or wire presses may be considered to be utilized as well either alone or connected to series. Accordingly, as a defiberizer of the dry pulp, other apparatus may be utilized just as well as the conventional pulpers. The only precondition for the defiberizer is that it must be capable of defiberizing the dry broke to a form that may be returned back to the process.
1. A method of treating broke, according to which method broke material obtained from
a paper, paperboard or the like production machine is diluted, defiberized and thickened
for storing at a high consistency, characterized in that after said dilution and defiberizing the broke is taken directly to a thickening
device by means of which it is thickened to a high consistency and from which it is
taken into a storage container (38) at a consistency of 12 - 45 %.
2. A method according to claim 1, characterized in that the filtrate obtained from said thickening is returned back to said defiberizing
to be used as dilution liquid.
3. A method according to claim 1 or 2, characterized in that said thickening is practiced with a press (36).
4. A method according to claim 1, 2 or 3, characterized in that the filtrate obtained from said thickening is treated in order to remove undesired
material from said filtrate.
5. A method according to claim 4, characterized in that the filtrate obtained from said thickening is treated by means of a fiber-recovery
device (54).
6. A method according to claim 5, characterized in that at least part of the dilution liquid in the defiberizing is clear filtrate of the
fiber-recovery device (54).
7. A method according to claim 1, 2 or 3, characterized in that the filtrate obtained from said thickening is returned directly back to said defiberizing
to be used as dilution liquid e.g. when there is maximum amount of broke to be treated
or the water amount required for diluting the broke is big.
8. A method according to claim 4, characterized in that the filtrate obtained from said thickening is treated in order to remove undesired
material from the filtrate when the defiberizing and the thickening are practiced
at constant loading.
9. A method according to claim 5, characterized in that the clear filtrate of the fiber-recovery device (54) is used as liquid being stored
for the dilution in the defiberizing.
10. An apparatus for treating broke comprising one or several broke defiberizer/s (10)
which may be a pulper or the like, a broke thickening device and a broke storage container,
characterized in that said defiberizer (10) is connected via a flow path (33) directly, without an intermediate
tank, with the thickening device (36).
11. An apparatus according to claim 10, characterized in that said thickening device (36) is a press.
12. An apparatus according to claim 10 or 11, characterized in that said thickening device (36) is provided with means (40) for receiving the filtrate
and that said means (40) for receiving the filtrate are connected via a flow path
(44) with said defiberizer (10).
13. An apparatus according to claim 12, characterized in that said means (40) for receiving the filtrate are connected via a flow path (48) with
means (50) for removing the undesired material from the filtrate.
14. An apparatus according to claim 12, characterized in that said means (40) for receiving the filtrate are connected to a fiber-recovery device
(54).
15. An apparatus according to claim 14, characterized in that said means (40) for receiving the filtrate are connected to a treatment system (58)
for treating the turbid filtrate of the fiber-recovery device (54).
16. An apparatus according to claim 10, characterized in that the treatment and recirculation system for the filtrate of the thickening device
(36) comprises a fiber-recovery device (54) and a clear filtrate storage container
(32) as well as the required number of pumps.
17. An apparatus according to claim 16, characterized in that the treatment and recirculation system for the filtrate of the thickening device
(36) further comprises an undesired material separating means (50) prior to the fiber-recovery
device (54).
18. An apparatus according to claim 10, characterized in that said thickening device (36) is provided with means for taking the thickened broke
into the HC - storage container (38).
19. An apparatus according to claim 10, characterized in that said thickening device (36) is dimensioned to treat the whole output of the production
machine if necessary.
1. Verfahren zur Behandlung von Ausschuss, nach welchem Verfahren von einer Papier-,
Karton oder einer ähnlichen Produktionsmaschine stammendes Ausschussmaterial verdünnt,
defibriert und eingedickt wird zur Lagerung bei einer hohen Konsistenz, dadurch gekennzeichnet, dass der Ausschuss nach Verdünnung und Defibrierung direkt einer Eindickungsvorrichtung
zugeleitet wird, mit der er auf eine hohe Konsistenz eingedickt wird und aus der er
in einen Lagerbehälter (38) bei einer Konsistenz von 12-45 % geleitet wird.
2. Verfahren nach Patentanspruch 1, dadurch gekennzeichnet, dass das bei der Eindickung anfallende Filtrat zur Defibrierung zurückgeführt wird, um
als Verdünnungsflüssigkeit verwendet zu werden.
3. Verfahren nach Patentanspruch 1 oder 2, dadurch gekennzeichnet, dass die Eindickung mit einer Presse (36) vorgenommen wird.
4. Verfahren nach Patentanspruch 1, 2 oder 3, dadurch gekennzeichnet, dass das bei der Eindickung anfallende Filtrat behandelt wird, um unerwünschtes Material
aus dem Filtrat zu entfemen.
5. Verfahren nach Patentanspruch 4, dadurch gekennzeichnet, dass das bei der Eindickung anfallende Filtrat mit einer Faserrückgewinnungsvorrichtung
behandelt (54) wird.
6. Verfahren nach Patentanspruch 5, dadurch gekennzeichnet, dass zumindest Teil der Verdünnungsflüssigkeit bei der Defibrierung Klarfiltrat der Faserrückgewinnungsvorrichtung
(54) ist.
7. Verfahren nach Patentanspruch 1, 2 oder 3, dadurch gekennzeichnet, dass das bei der Eindickung anfallende Filtrat direkt zur Defibrierung zurückgeleitet
wird, um z. B. als Verdünnungsflüssigkeit verwendet zu werden, wenn es gilt, eine
maximale Ausschussmenge zu behandeln oder die zur Verdünnung des Ausschusses erforderliche
Flüssigkeitsmenge groß ist.
8. Verfahren nach Patentanspruch 4, dadurch gekennzeichnet, dass das bei der Eindickung anfallende Filtrat wird behandelt wird, um unerwünschtes Material
aus dem Filtrat zu entfemen, wenn Defibrierung und Eindickung bei konstanter Belastung
durchgeführt werden.
9. Verfahren nach Patentanspruch 5, dadurch gekennzeichnet, dass das Klarfiltrat der Faserrückgewinnungsvorrichtung (54) als Flüssigkeit verwendet
wird, die für die Verdünnung bei der Defibrierung eingelagert wird.
10. Vorrichtung zur Behandlung von Ausschuss, die sich aus einem oder mehreren Ausschussdefibrator/en
(10), wobei es sich um einen Pulper oder ähnliches handeln kann, einer Ausschuss-Eindickungsvorrichtung
und einem Ausschuss-Lagerbehälter zusammensetzt, dadurch gekennzeichnet, dass der Defibrator (10) über einen Strömungspfad (33) direkt, ohne Zwischenbehälter,
mit einer Eindickungsvorrichtung (36) verbunden ist.
11. Vorrichtung nach Patentanspruch 10, dadurch gekennzeichnet, dass die Eindickungsvorrichtung (36) eine Presse ist.
12. Vorrichtung nach Patentanspruch 10 oder 11, dadurch gekennzeichnet, dass die Eindickungsvorrichtung (36) mit Mitteln (40) zur Aufnahme des Filtrats versehen
ist und dass die Mittel (40) zur Aufnahme des Filtrats über einen Strömungspfad (44)
mit dem Defibrator (10) verbunden sind.
13. Vorrichtung nach Patentanspruch 12, dadurch gekennzeichnet, dass die Mittel (40) zur Aufnahme des Filtrats über einen Strömungspfad (48) mit Mitteln
(50) fürs Entfernen des unerwünschten Materials aus dem Filtrat verbunden sind.
14. Vorrichtung nach Patentanspruch 12, dadurch gekennzeichnet, dass die Mittel (40) zur Aufnahme des Filtrats mit der Faserrückgewinnungsvorrichtung
verbunden (54) sind.
15. Vorrichtung nach Patentanspruch 14, dadurch gekennzeichnet, dass die Mittel (40) zur Aufnahme des Filtrats mit einem Aufbereitungssystem verbunden
(58) sind zur Aufbereitung des Trübfiltrats der Faserrückgewinnungsvorrichtung (54).
16. Vorrichtung nach Patentanspruch 10, dadurch gekennzeichnet, dass das Aufbereitungs- und Rückführsystem für das Filtrat der Eindickungsvorrichtung
(36) eine Faserrückgewinnungsvorrichtung (54) und einen Klarfiltrat-Lagerbehälter
(32) sowie die erforderliche Anzahl Pumpen umfasst.
17. Vorrichtung nach Patentanspruch 16, dadurch gekennzeichnet, dass das Behandlungs- und Rückführsystem für das Filtrat der Eindickungsvorrichtung (36)
des Weiteren Trennmittel (50) für unerwünschtes Material vor der Faserrückgewinnungsvorrichtung
(54) umfasst.
18. Vorrichtung nach Patentanspruch 10, dadurch gekennzeichnet, dass die Eindickungsvorrichtung (36) mit Mitteln zur Leitung des eingedickten Ausschusses
in den HC-Lagerbehälter (38) versehen ist.
19. Vorrichtung nach Patentanspruch 10, dadurch gekennzeichnet, dass die Eindickungsvorrichtung (36) notfalls zur Aufbereitung des gesamten Ausstoßes
der Produktionsmaschine bemessen ist.
1. Procédé de traitement de la pâte aux cassés de fabrication selon lequel le matériau
de cassés de fabrication obtenu de la machine à papier ou à carton, ou autre machine
de production similaire, est dilué, défibré et épaissi pour stockage à une consistance
élevée, caractérisé en ce qu'après lesdites dilution et défibrage la pâte aux cassés de fabrication est conduite
directement au dispositif d'épaississement à l'aide duquel elle est épaissie à une
consistance élevée et à partir duquel elle est conduite vers une cuve de stockage
(38) à une consistance de 12 à 45 %.
2. Procédé selon revendication 1 caractérisé en ce que le filtrat obtenu lors dudit épaississement est retourné vers ledit défibrage afin
de servir en tant que liquide dilutif.
3. Procédé selon revendication 1 ou 2 caractérisé en ce que ledit épaississement se déroule à l'aide d'une presse (36).
4. Procédé selon revendication 1,2 ou 3 caractérisé en ce que le filtrat obtenu dudit épaississement est traité afin d'en extraire le matériau
indésirable dudit filtrat.
5. Procédé selon revendication 4 caractérisé en ce que le filtrat obtenu dudit épaississement est traité à l'aide d'un dispositif de récupération
de fibres (54).
6. Procédé selon revendication 5 caractérisé en ce que au moins une partie du liquide dilutif du défibrage est constitué du filtrat clair
du dispositif de récupération de fibres (54).
7. Procédé selon revendication 1,2 ou 3 caractérisé en ce que filtrat obtenu dudit épaississement est retourné directement vers ledit défibrage
pour être utilisé par exemple en tant que liquide dilutif lorsque la quantité des
cassés à traiter est maximale ou lorsque la quantité de liquide exigée pour diluer
les cassés est élevée.
8. Procédé selon revendication 4 caractérisé en ce que le filtrat obtenu dudit épaississement est traité afin d'en extraire la matière indésirable
lorsque le défibrage et l'épaississement se maintiennent à charge constante.
9. Procédé selon revendication 5 caractérisé en ce que le filtrat clair venant du dispositif de récupération de fibres (54) est utilisé
en tant que liquide stocké pour le défibrage.
10. Dispositif pour le traitement de la pâte de cassés de fabrication qui comprend un
ou plusieurs défibreur(s) (10) soit un désintégrateur ou similaire, un dispositif
d'épaississement et une cuve de stockage, caractérisé en ce que ledit défibreur (10) est couplé via une voie de passage (33) directement avec le
dispositif d'épaississement (36) sans cuve intermédiaire.
11. Dispositif selon revendication 10 caractérisé en ce que ledit dispositif d'épaississement est une presse (36).
12. Dispositif selon revendication 10 ou 11 caractérisé en ce que ledit dispositif d'épaississement (36) est muni d'un dispositif (40) pour recevoir
le filtrat et que ledit dispositif (40) destiné à recevoir le filtrat est couplé via
une voie de passage (44) avec ledit défibreur (10).
13. Dispositif selon revendication 12 caractérisé en ce que ledit dispositif (40) pour recevoir le filtrat est couplé via une voie de passage
(48) avec le dispositif (50) pour extraire la matière indésirable du filtrat.
14. Dispositif selon revendication 12 caractérisé en ce que ledit dispositif (40) pour recevoir le filtrat est couplé avec le dispositif de récupération
du fibre (54).
15. Dispositif selon revendication 14 caractérisé en ce que ledit dispositif (40) pour recevoir du filtrat est couplé à un système de traitement
(58) pour traiter le filtrat trouble du dispositif de récupération de fibres (54).
16. Dispositif selon revendication 10 caractérisé en ce que le système de traitement et de recirculation du filtrat du dispositif d'épaississement
(36) comprend un dispositif de récupération de fibres (54) et une cuve de stockage
du filtrat clair (32) aussi bien qu'un nombre suffisant de pompes.
17. Dispositif selon revendication 16 caractérisé en ce que le système de traitement et de recirculation du filtrat du dispositif d'épaississement
(36) comprend ultérieurement un dispositif pour séparer la matière indésirable précédant
le dispositif de récupération de fibres (54).
18. Dispositif selon revendication 10 caractérisé en ce que le dispositif d'épaississement (36) est muni d'un dispositif pour conduire la pâte
aux cassés de fabrication épaissie dans une cuve de stockage à consistance élevée
(38).
19. Dispositif selon revendication 10 caractérisé en ce que ledit dispositif d'épaississement (36) est prévu à traiter toute la sortie de la
machine de production, si nécessaire.