FR2801065A1 - PROCESS FOR REPAIRING RAW MATERIALS SUCH AS PAPERS, CARDBOARDS, CELLS, PREHYDRATION DEVICE FOR IMPLEMENTING THE PROCESS AND INSTALLATION - Google Patents

Abstract

Process for re-pulping raw material bales of the paper, cardboard or cellulose type, according to which:. the bales of raw materials are first opened so as to obtain individualized plates ;. then, where appropriate, the impurities are separated from the individualized plates, characterized in that the size of said individualized plates is prehydrated and then reduced before their subsequent introduction into a pulper, the steps of prehydration and of reduction in size of the raw material , and where appropriate separation of impurities, being carried out in a single step in one and the same enclosure.

Description

1 PROCESS FOR REPAIRING RAW MATERIALS FROM

  TYPE OF PAPERS, CARDBOARDS, CELLS, PREHYDRATION DEVICE FOR IMPLEMENTING THE PROCESS AND INSTALLATION5

  The invention relates to a process for re-pulping raw materials such as paper, cardboard and celluloses. It also relates to a device for

  prehydration and reduction of the size of the raw material for the implementation of the process. Finally, it relates to an installation for re-pulping of raw material using the device.

  The pulping or defibration of papers is carried out in a known manner within pulpers and consists in transforming dry and solid papers into pulp.

  Generally, the pulping of paper is carried out from compact bales, which are kept encircled so as to maintain their compactness.

  When the bales of paper consist of old paper, for example old white paper or old brown paper, these also include a certain number of impurities, such as plastic sheets, glasses, metals, sands, stones, pebbles, etc. , whose volume and mass can represent a significant part. In contrast, virgin cellulose bales are free from

  all troublesome impurities, in principle.

  In some installations, the bales are first deposited on conveyors, then the wires are cut manually or automatically.

  The compact bales are then conveyed to the pulper, in which they are precipitated as such with, if appropriate, all of their impurities.

  With regard to the pulping of old paper, the heavy impurities released in the pulper, during disintegration, such as sand, stones, threads

  iron and others, by abrasion wear the faces and edges of the rotor, as well as the perforated plate under or next to the rotor.

  Furthermore, both for pulping old paper and for virgin cellulose, the pulper uses a large amount of consumed energy 2 to the extent that it is necessary, before the disintegration operation properly

  so-called paper, break the ball and moisten its fibrous components beforehand.

  To solve these problems, document US-A-4,812,205 proposes a method and an installation for re-pulping old paper comprising the

following steps.

  First, the bales of paper are conveyed to a device for opening and reducing the size of the bale. The individualized paper plates from this step are then poured onto a second device intended to separate from the paper plates, the contaminating agents of the glass, metal and other type. The paper is then transported to a hydration device arranged above the pulper. 15 If indeed, such an installation allows the pulper to implement a

  less energy consumed, however, it has a number of drawbacks.

  First of all, the means used to separate the impurities from the paper are in the form of a set of discs in combination with magnets, which if they effectively allow the paper to be separated from the small impurities, do not allow separating large heavy impurities. Consequently, heavy impurities accumulate on the surface of the discs25 and lead to blocking the system or are transferred to the pulper. In addition, such an installation remains complex and expensive, and the paper losses of small

  dimensions may be important.

  Therefore, the problem that the invention proposes to solve is to develop a pulping process, both of old paper and of virgin cellulose, using a simple, inexpensive installation while

  now at the level of the pulper, much less energy consumed, and very little wear and tear on its main element, namely the rotor.

  To do this, the invention provides a process for re-pulping bales of raw materials of the paper, cardboard, cellulose type, according to which: e first of all, the uncoupled bales of raw materials are opened so as to obtain individualized plates ; * then, if necessary, the impurities are separated from the individualized plates, characterized in that they are prehydrated and the size of said plates is then reduced

  individualized before their subsequent introduction into a pulper, the steps of prehydration and reduction of size of the raw material, and if necessary of separation of the impurities, being carried out in a single step in a single and same enclosure.

  Of course, the process of the invention relates to the pulping of old paper as well as that of virgin cellulose. However, unlike the old

  paper, the treatment of virgin cellulose does not require a step of separation15 of heavy impurities, insofar as it does not contain, a priori, any annoying impurities.

  Thus, the process of the invention does not consist in carrying out the operations of prehydration and reduction of size of the raw material, and if necessary of

  separation of impurities in two separate steps, but in one step.

  It follows that this operation in a single step makes it possible to carry out the reduction in size and, where appropriate, the separation of the raw material not on dry material, as is the case in the document US-A- 4,812,205, but in an aqueous medium, which allows better separation by difference in densities,

  dense impurities and this, while prehydrating the raw material.

  In a first embodiment of the method, the prehydration step

  of the raw material is made by watering.

  In a second embodiment, the step of prehydrating the material

  first is done by immersion and watering.

  The invention also relates to a device for prehydrating and reducing the size of the raw material for implementing the method.

previously described.

  In a first embodiment, that is to say when the prehydration is carried out by watering, the device comprises an open enclosure equipped

  on the one hand, watering means, and on the other hand, means capable of reducing the size and transferring the sheets of raw material.

  According to a first characteristic of the device, the watering means are in the form of at least one rinser.

  In an advantageous embodiment, and to obtain a uniform watering of the raw material, the rinsers are located at the upper part of the

tank.

  Furthermore, and according to a second characteristic of the device, the means capable of reducing the size and transporting the raw material are in the form of at least one transfer screw with sharp edges.

  Of course, the number of transfer screws varies depending on the production.

  In a first embodiment, the transfer screws are two in number and are parallel. They are fitted with sharp-edged turns intervening

  like knives and counter knives, between them or with bars arranged at the bottom of the tank.

  In a second embodiment, there are two transfer screws, the first screw being intended to force-feed a second screw positioned perpendicular to said first screw, the two screws working at different speeds. Such an arrangement makes it possible to reduce the size of the raw material by

  forming a plug at the end of the first screw, said plug then being subjected to the cutting of the second screw.

  In a third embodiment, there are four transfer screws, the third screw being placed under the first two screws and intended to force-feed a fourth perpendicular screw and turning faster than said third

  screw, in order to always reduce the size of the raw material entering the pulper to facilitate its hydration and reduce the power of shredding.

  Therefore and in practice, the open bales are poured into the enclosure, the raw material then being subjected to intensive watering leading to its softening, while being simultaneously reduced in size thanks to the presence of cutting transfer screws. The transfer screws are simultaneously responsible for transporting the raw material to the next workstation, that is to say the pulper. In addition, part of the water can act in a closed circuit and withdrawal is carried out continuously through a perforated plate for possible treatment in

  cyclonic scrubbing to remove dense impurities. The water is reused.

  As already said, the device for prehydration and reduction in size of the

  raw material can be used both for re-pulping of virgin cellulose and waste paper.

  In the latter case, to recover the heavy impurities fallen by gravity or separated from the raw material by the rinsers, the bottom of the enclosure is inclined

  and includes recovery means.

  In practice, but not limited to, the recovery means are in the form of an airlock with heavy impurities.

  In a second embodiment, that is to say when the hydration of the raw material is carried out by immersion, the device of the invention is

  present in the form of a swimming pool equipped with means capable of reducing the size and transferring the raw material.

  As previously, the means capable of reducing the size and transferring the raw material are in the form of at least one transfer screw to

cutting edge.

  Thus, in a first embodiment, the transfer screws are two in number, of the knife and counter knife type, and are parallel. They are

6 2801065

  equipped with coils with sharp edges acting as knives and counter knives, between them or with bars arranged at the bottom of the tank.

  Similarly, in a second embodiment, there are two transfer screws, the first screw being intended to force-feed a second screw positioned perpendicular to said first screw, the two screws working at different speeds. In a third embodiment, there are four transfer screws, the third screw being placed under the first two screws and intended to force-feed a fourth perpendicular screw and rotating faster than said third screw. From then on and in practice, the open raw material balls are poured into the swimming pool, the impurities then falling by gravity into the bottom of the swimming pool, while the raw material then prehydrated is reduced in size by the cutting screws. As before, the transfer screws are simultaneously responsible for transporting the raw material to the next workstation, i.e. the pulper. 20 To facilitate the movement of the raw material up to the cutting transfer screws, and therefore prevent the open raw material plates from

  stagnate at the entrance of the pool, several solutions can be envisaged.

  In a first embodiment, the cutting screws are positioned in the bottom of the swimming pool, the water level being chosen sufficiently low, so

  that the transfer screws can drive the plates.

  In a second embodiment, the swimming pool is equipped with at least one

  pressurized water supply nozzle creating a hydraulic current, allowing the plates to be pushed towards the screws.

  To recover heavy impurities that have fallen to the bottom of the pool, the bottom of the pool is equipped with recovery means, in particular in the form of an airlock.

heavy impurities.

  Furthermore, to allow all the heavy impurities that have fallen on the inclined bottom of the pool to be recovered, said bottom can be equipped with a system

of cruising.

  To allow maximum elimination of the sand present on the raw material, the pool is also equipped with at least one rinser, the rinsing water

  possibly being treated in cyclonic scrubbers.

  Finally, to allow: - on the one hand, the advance of the raw material on the surface of the pool; - And secondly, its immersion so as to facilitate the separation of heavy impurities; the swimming pool can also be equipped with beaters in the form, for example, of paddle wheels.15

  As already said, the invention also relates to the installation for re-pulping of raw materials incorporating the device described above.

  More specifically, the invention relates to an installation for re-pulping raw material of the paper, cardboard or cellulose type, comprising: * a means of transporting bales of raw materials; * a means of cutting, removing and conditioning the wires surrounding the balls; * a means of opening the balls; * the device for prehydration and reduction of the raw material described above;

  * a pulper able to carry out the pulping proper.

  The invention and the advantages which result therefrom will emerge more clearly from the examples.

  following embodiments, in support of the appended figures.

  Figure 1 is a schematic representation of the device for prehydration and reduction of size of the raw material by sprinkling according to the invention.

  Figure 2 is a schematic representation of the device by immersion of

  prehydration and reduction of the size of the raw material according to the invention according to a first embodiment.

  Figure 3 is a schematic representation of the device by prehydration immersion and reduction of the size of the raw material by immersion according to the invention according to a second embodiment. Figure 4 is a schematic representation of an installation for pulping incorporating the device shown in Figure 2. As already said, the invention relates to pulping, especially of virgin cellulose or waste paper. It is in relation to these that it is more particularly described in the following examples. 10 The device for prehydrating and reducing the size of the bales of raw material shown in FIG. 1 comprises an open enclosure with an inclined bottom (1) at the level of which are arranged an airlock with heavy impurities (2) and a second trap

with stones (3).

  To ensure the actual prehydration of the raw material, the device is equipped with rinsers (5) arranged at the top of the enclosure.

  The enclosure further comprises two parallel cutting screws (4), said screws

  being able to reduce the size of the moistened paper and transport the raw material to the next work station.

  In practice, the uncoupled and open balls are precipitated in the enclosure, the rinsers are actuated. As the raw material plates are hydrated, these are shredded by the screws, then the impurities which have fallen into the bottom of the tank by gravity or by the action of the rinsers, are led into the airlock with heavy impurities and / or the stone trap. The coarsely shredded paper plates and the water are then transferred by means of the screws to the pulper (not shown). In FIG. 2, the device for pre-hydration and reduction of size of the raw material is shown by immersion, particularly recommended for

  highly contaminated raw materials.

  The device consists of a swimming pool (6), the bottom of which is provided with a dirt trap (7). The pool is further equipped with two transfer screws, 9 respectively a first screw (8) with sharp edges intended to force-feed a second

  screw (9) positioned perpendicular to the end of the screw (8).

  In addition, to promote the movement of the raw material in the direction of the cutting screws (8), the wall (10) of the swimming pool is equipped with water supply nozzles (11) under pressure, allowing a hydraulic current to be created . In addition, to promote the immersion of the plates and also the separation of the impurities from said plates, the swimming pool is also equipped with beaters under

paddle wheel shape (12).

  At the same time, the pool is equipped with rinsers (13) allowing the maximum sand present in the raw material to be removed.

  Similarly, the bottom of the pool is equipped with a dredging system (15) capable of driving dense impurities to an airlock.

  The rinsing water is then treated in a cyclonic purification (14).

  In operation, the raw material plates fall to the surface of the pool and are displaced by the hydraulic current created by the nozzles

  water supply (11) to the conveyor screw (8). The transport screw shreds the prehydrated raw material and the cup to form a stopper (23), which in turn is shredded by the perpendicular screw (9).

  In FIG. 3, a second embodiment of the swimming pool has been shown, in which a booster screw (25) is interposed between the transport screw (8) and the

screw (9).

  In Figure 4, there is shown an installation for re-pulping of raw material of the paper, cardboard or cellulose type integrating the

  prehydration and reduction of the size of the raw material previously described.

  This installation consists of: * a means of transport (16) of raw material bales; * a unit for cutting, removing (17) and conditioning the wires of the iron surrounding the bales of raw material; * a unit for opening the bale of raw material (18); * of the device of the invention (19) according to the embodiment of Figure 2;

* a pulper (20).

  In known manner, the means of transport of the raw material bales is

  present as a treadmill.

  Furthermore, the decoupling of the paper ball can be done either manually or by means of an automatic machine not shown.

  The paper ball thus uncovered is then opened by means of a transport screw (24) simultaneously ensuring the separation into individualized plates and the

  separation of heavy impurities from the raw material, which fall to the bottom of the screw support tank.

  The individualized raw material plates are simultaneously conveyed into the prehydration, size reduction and

  separation of heavy impurities from the raw material (19) corresponding to the device described above.

  The raw material thus freed from the majority of heavy impurities, moistened and shredded and is simultaneously conveyed to the pulper, which

  ensures proper pulping.

  The advantages of the invention appear clearly from the description.

  Note in particular the effectiveness of the device not only for removing heavy impurities, but also for prehydration, making it possible to reduce the size of the raw material with reduced energy consumed, and thus to optimize the subsequent work of the pulper. .35 In addition, the device can be implemented in pulping installations and makes it possible to avoid any wear of the pulper thanks to the prior elimination of the

heavy impurities.

Claims (14)

  1 / Process for re-pulping bales of raw materials of the paper, cardboard, cellulose type, according to which: e firstly bales of raw materials are opened so as to obtain individualized plates; * then, if necessary, the impurities are separated from the individualized plates, characterized in that one prehydrates and then the size of said individualized plates is reduced before their subsequent introduction into a pulper, the stages of prehydration and reduction of size of the material first, and the case   separation of impurities, being carried out in a single step in a single enclosure.   2 / A method according to claim 1, characterized in that the step of   prehydration of the raw material is carried out by watering.   3 / A method according to claim 1, characterized in that the step of prehydration of the raw material is carried out by immersion and watering.   4 / device for prehydration and reduction of the size of the raw material for the implementation of the process which is the subject of one of claims 1 to 2,   characterized in that it comprises an open enclosure (1) equipped on the one hand, with watering means (5) and on the other hand, means (4) capable of reducing the size and transferring the raw material. / Device according to claim 4, characterized in that the watering means are in the form of at least one rinser (5) located at the part top of the tank.   6 / Device according to one of claims 4 to 5, characterized in that the means capable of reducing the size and transferring the raw material are presented under   forms at least one cutting edge transfer screw (4).   7 / Device according to claim 6, characterized in that the transfer screws are two in number, the first screw being intended to force-feed a second screw 13 positioned perpendicular to said first screw, the two screws working at different speeds.   8 / Device according to claim 6, characterized in that the transfer screws are four in number, the third screw being arranged under the first two screws and intended to force-feed a fourth perpendicular screw and rotating faster than said third screw.   9 / Device according to one of claims 4 to 8, characterized in that the   bottom of the enclosure is inclined and comprises means for recovering impurities, in particular in the form of an airlock with heavy impurities (2).   / Device for prehydrating and reducing the size of the raw material for implementing the process which is the subject of claims 1 or 3,   characterized in that it is in the form of a swimming pool (6) equipped with means capable of reducing the size and transferring the raw material.   11 / Device according to claim 10, characterized in that the means capable of reducing the size and transferring the raw material are in the form   at least one cutting edge transfer screw, acting against, at least, a bar fixed to the bottom of the tank.   12 / Device according to claim 11, characterized in that the transfer screws are two in number, the first screw (8) being intended to force-feed a second screw (9) positioned perpendicular to said first screw, the two screws   working at different speeds.   13 / Apparatus according to claim 11, characterized in that the transfer screws are four in number, the third screw (25) being arranged under the first two screws (8) and intended to force-feed a fourth perpendicular screw (9) and   rotating faster than said third screw.   14 / Device according to one of claims 10 to 13, characterized in that the   swimming pool is equipped with at least one pressure water supply nozzle (11) creating a hydraulic current.   / Device according to one of claims 10 to 14, characterized in that the bottom of the pool is equipped with means for recovering impurities, in particular   in the form of a heavy impurity lock (7).   16 / Device according to one of claims 10 to 15, characterized in that the pool surface is equipped with beaters (12) in the form of impellers.   17 / Installation for re-pulping the raw material of the paper, cardboard or cellulose type comprising: e a means of transport (16) of raw material bales; * means for cutting, removing (17) and conditioning the wires of the iron surrounding the ball of raw material (18); * a means of opening the balls;   * the prehydration device (19) which is the subject of one of claims 4 to 16;   * a pulper (20) capable of carrying out the pulping proper.