FR2503748A1 - METHOD AND DEVICE FOR PROCESSING OLD PAPERS - Google Patents

Abstract

PROCESS AND DEVICE FOR TREATING OLD PAPER RELATIVELY CLEANED AND PREVIOUSLY SORTED, IN PARTICULAR WASTE FROM PAPER MANUFACTURING, THE PROCESS INCLUDING THE PHASES WHICH CONSIST IN DISSOLVING THE MATERIAL TO BE TREATED IN A PULIST 1 UNTIL 15 ; SORT THE DOUGH BY PASSING IT CLOSE TO A METAL DETECTOR 5; INTRODUCE THE DOUGH INTO A DISPERSING APPARATUS 4 WHOSE WORKING CAPACITY CORRESPONDS TO THE RANGE OF CONSISTENCIES REGULATED IN PULPER 1; DISPERSING THE PAPER PULP INTO THE DISPENSER 4, THEN DILUTE THE MATERIAL SO OBTAINED, AND FINALLY TREAT THE MATERIAL BY FINE SORTING AND PURIFICATION TO THEN FEED THE MACHINE FOR MAKING THE PAPER OR CARDBOARD. APPLICATION TO THE PAPER AND BOARD INDUSTRY IN GENERAL.

Description

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  The invention relates to a method of treating waste paper.

  So far, recovered waste paper was either dissolved to a lower consistency in a mill or pulper, before being subjected to subsequent processing steps such as bleaching, sorting and thickening, or dissolved in a pulper until to a

  tance, for example by more than 20%, after which they were diluted

  in the pulp where they are reduced to a consistency that allows pumping and sorting from the pulp to feed other

  treatment. In this process, it was necessary in any case to resort to

  thickener, which increased the cost of the entire process and increased

was particularly bulky.

  The problem to be solved by the present invention consists in producing a simplified method, which is more particularly combined with the part of paper making that recycles relatively clean old paper, that is to say either papers previously sorted, either waste paper, or waste, for example the resistant fraction

in the wet state.

  This problem is solved according to the present invention which proposes a rapid and continuous process which, compared to the known methods, is

significantly simplified.

  This method is particularly advantageous when it comes to

  old, relatively soiled papers, by which, it is necessary to

  dre under the heading of disruptive impurities heavy elements such as screws, pebbles, wire, etc., and important surface elements such as leaves, pieces of wood, textiles, etc., as in this case, we results in a very fast processing process for waste paper until reuse in the papermaking machine; in this case, the printing inks they contain will not be eliminated but

  rather finely distributed in the next process.

  A particularly advantageous embodiment of the method consists in using a disc mill, since the working point and the effect produced can be adapted to the consistency of the material by

  the interval between the two disks, which makes

  free choice of the consistency of the material in the mill.

  The invention will be better understood from the following description

  of a possible embodiment, if we refer to the single Figure of the

  attached drawing which shows schematically the whole of a pre-installation

  view for the implementation of the method of the invention.

  we see on the drawing that the path followed by the fibrous material

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  Between the pulper 1 and the disc mill 4 passes through a stop member 10,

  an endless screw 2 and an endless belt conveyor-3, the

  the pension being dispersed in the disk mill 4. Above the belt conveyor 3 is a metal detector 5 intended to give the certainty that no metal part contained in the suspension, such as, for example, screws, staples of Bindings, or the like, can arrive with the fibrous material in the next sorting apparatus, or even in the papermaking machine. In the disc mill 4 the material is defibrce

  to the necessary fineness, ie by dissolving the fibers indi-

  viduals and by dispersing, for example, the printing ink which it

  is holding. In this process, the consistency of the material is about 20% or more, and it will be kept continuously unchanged between the pulper and the disc mill. The favorable consistency of the material, which can also be less than 20%, can be chosen either because of the operating mode of the pulp taken separately, or taking into account the possibilities offered by the disc mill, that is to say of the spacing

  possible between them. In general, however, we will act

  to adjust the dynamic operating point of the disc mill by the integral adjustment of the gap between discs or working slots of the disc mill.

  way to obtain the most favorable consistency for the pulp.

  Of course, it is also possible to choose, instead of a disk mill, another dispersing apparatus, in particular for example a single-cylinder mill, of the type having no adjustable working slot, so that it can not be used. freely choose the consistency of the material in the

  pulp, since it is necessary to guide oneself according to the dynamic operating point.

  (as favorable as possible) of the single cylinder mill.

  Beyond the disc mill, the material is transferred by a

  reverse worm mode reversing in operating mode

  tinu, to an intermediate vat 8, o is a dilution. This is essential to guarantee the presumed conditions with regard to the

  possibility of sorting, especially in view of later sorting and puri

  fication of the material. The material is extracted from the intermediate vat 8

  9. These devices can be followed by different

  sorting lines, such as screen sorters, including vertical dividers

  and also flotation facilities. These can be omitted

  its, of course, in case one would use as old paper

  unprinted waste paper and / or only clippings (waste) from the

  paper making. When the installation is started, the endless belt conveyor 7 can be operated in the opposite direction so

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  to return the material in the pulper 1 by means of a trans-

  endless carrier 11, because at the start of the installation it takes a certain transition time before the material has

  the properties required downstream of the disc mill.

  The drawing also shows schematically how the grinding mill

  4 is supplied with fibrous material by means of a screw of

  12. If a single cylinder mill is used, the material taken from pulp 1 should have a very high consistency, possibly, for example, about 30% and in exceptional cases up to 35%. , which however will have to be overcome in full. In the case

  of a disc mill, the consistencies will be lower and can

  to a greater extent, as already indicated.

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Claims (6)

REVENDICA T IONS   1. Process for the treatment of pre-sorted old paper and   relatively refined, including paper waste resulting from the manufacture of   cation of paper, characterized by the following phases: a) Dissolution in pulp pulp 1 to obtain a strength greater than 15%, b) removal in the pulper 1 of the material at the consistency defined therein C) sorting the paper pulp by passing it in the vicinity of a detector 5 of metal bodies, d) introducing the pulp into a dispersion apparatus 4 whose working zone is within the limits of the consistency of the material fixed by the setting made in the pulper 1, e) dispersion of the pulp in the dispersion apparatus 4, f) dilution of the pulp,   (g) continuous treatment of pulp with fine sorting and   2. Method according to Claim 1, characterized in that the con-   The strength of the pulp in pulp 1 is adjusted according to the   working point (as optimal as possible) of the dispersion apparatus 4.   3. A process according to any one of claims 1 or 2, characterized   by the use of a dispersion apparatus at intervals of   adjustable vane, for example a disc mill, said interval being   adjusted to ensure an optimal mode of operation according to the con- resistance of the material.   4. A process according to any one of claims 1 to 3,   characterized in that extraction of the pulp from the pulper (1) is carried out by means of worm or pallet slats or conveyor belts unending.   5. Device for implementing the method according to any one   according to Claims 1, 2 or 4, characterized in that the device   dispersion is constituted by a single cylinder mill.   6. Device for implementing the method according to any one   conque of Claims 1, 3 or 4, characterized in that the device   dispersion (4) is constituted by a double-disc mill, the   valle between the discs that can be set according to the consistency dough.