Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
  • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
  • D21B1/30—Defibrating by other means
  • D21B1/34—Kneading or mixing; Pulpers
  • D21B1/345—Pulpers
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
  • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
  • D21B1/30—Defibrating by other means
  • D21B1/34—Kneading or mixing; Pulpers
  • D21B1/345—Pulpers
  • D21B1/347—Rotor assemblies

Definitions

• the invention relates to a pulper for defibering raw materials such as paper, cardboard or cellulose.
• the pulper of the invention applies more particularly to the re-pulping of all kinds of fibrous materials, in bales or in bulk, and more particularly of brown waste paper, of old white paper for the purpose of deinking, for example, but also to the re-pulping of virgin celluloses.
• old paper whether brown or white, is recovered and stored generally in the form of compact bales, which are kept encircled, so as to maintain their compactness.
• Old paper bales are not only made of paper but also include a certain number of impurities such as plastic sheets, glass, metal, sand, stones, pebbles, etc., the volume and mass of which can represent a significant part. of the ball.
• pulping of virgin cellulose can be carried out at medium or high concentration, that is to say from 5-6% to 12-15%.
• pulping is often carried out in conventional pulpers at concentrations of the order of 5 to 6%.
• the document FR-A-2 544 756 describes a so-called "helical” pulper comprising a cylindrical tank provided at its bottom with a propeller-shaped turbine with a vertical axis imparting to the material a movement of axial downward circulation, followed by an ascending centrifugal movement from a smooth, then frustoconical bottom, equipped with deflectors. Even if this pulper has the advantage of disintegrating the paper well, and leaving little shredded impurities, in particular plastic sheets in the mass of the pulp, it nevertheless consumes significant specific energy.
• Document FR-A-2 169 240 describes a pulper for the disintegration of cellulose bales.
• This pulper comprises a cylindrical tank at the bottom of which is positioned a finned rotor, the lower faces of which have a cutter.
• This type of pulper even if it makes it possible to obtain a relatively satisfactory disintegration of the raw material, however requires the use of significant energy to allow the mixing of the mass of fibers and water.
• the energy necessary for the disintegration of paper with this kind of pulpers decomposes, as for all conventional pulpers in, an energy of disintegration proper, and an energy of circulation of the mixture of paper and water, necessary to continuously bring the raw material into contact with the rotor, in order to ensure its disintegration. Said circulation energy can reach or exceed, depending on the pulpers, half of the total energy consumed.
• the problem which the invention proposes to solve is to provide a pulper intended for defibering raw materials, the concept of which makes it possible to reduce the energy consumed, in particular the circulation energy, compared to pulpers of the prior art, thus reducing the cost of the pulping operation of raw materials such as paper, cardboard or cellulose.
• Another objective of the invention is to propose a pulper allowing the pulping of paper, cardboard or celluloses to be carried out higher fiber concentrations, in order to avoid stirring as much water as in the previous pulpers, and on the one hand, to reduce the volume of the pulper, and on the other hand, to reduce the energy specific consumption, to obtain, for a given production, the same disintegration effect.
• the invention provides a pulper intended for defibering raw materials of the paper, cardboard or cellulose type, comprising a tank whose bottom is equipped with means for discharging the defibrated raw material.
• This pulper is characterized in that said tank comprises at least one rotor capable of destructuring the raw material, said rotor being capable of being positioned in different zones distributed over the height of the tank.
• the pulper of the invention is equipped with rotors arranged over all or part of the height of the tank, which makes it possible to on the one hand, to reduce the circulation of the raw material and therefore the energy necessary for this circulation and on the other hand, to obtain a homogeneous disintegration of the raw material.
• the tank is associated with means making it possible to ensure the relative movement of the raw material relative to the rotor.
• the relative displacement of the raw material inside the tank relative to the rotor is obtained by making the rotor mobile relative to said tank or vice versa.
• the means making it possible to ensure the relative movement of the raw material contained in the tank in the direction of the rotor consist of at least a movable deflector.
• such deflectors are preferably three in number, the tank being cylindrical or cylindro-conical and they are driven in rotation parallel to the wall of said tank.
• the tank is cylindrical and the rotor is rotated around the central axis of said tank.
• the tank is of rectangular shape and the rotor is moved in translation parallel to one of the sides of said tank.
• the rotor is fixed and the tank moves.
• the tank is equipped with deflectors and moves the dough towards the rotors.
• the rotor and the tank are fixed, the displacement of the raw material in the direction of the rotor being obtained by means of movable deflectors.
• the rotor and the tank are fixed, the displacement of the raw material in the direction of the rotor being obtained by minimizing the space between the walls of the tank and the rotor.
• the pulper tank has from top to bottom a first hydration zone, the rotor being positioned in a second zone called “shredding” of the raw material.
• the pulper of the invention allows, within the same device:
• the hydration zone is equipped with at least two vertical screws capable of destructuring the entire bales of raw material, in particular of celluloses before introduction into the shredding zone of the pulper itself.
• the arrangement of vertical screws in the hydration zone makes it possible to force-feed the pulper in a forced and above all regular manner, which leads to a subsequent homogeneous disintegration of the raw material within the pulper.
• This system is particularly advantageous for re-pulping of cellulose, which does not contain heavy impurities liable to fall into the pulper tank and thus damage the rotors.
• the number of 2 screws is not limiting, and it is perfectly possible to envisage the presence of 4 screws, which will have the advantage of keeping the ball above the pulper tank as and when it is destructured .
• the screws are driven in a downward movement and can have a constant or variable pitch.
• provision can be made for the direction of the screws to be reversed, so as to unlock the ball.
• the top of the screws is of conical shape so as to be able to accept bales of raw material of different sizes.
• At least one rotor is positioned in a third zone called “defibering” of the material.
• the pulper of the invention acts in two, even three successive phases, respectively:
• the rotor arranged in the shredding zone designated hereinafter as the shredding rotor is in the form of at least one disc fitted with teeth.
• the shredding rotor is in the form of at least one disc fitted with teeth.
• those skilled in the art can choose any suitable rotor shape to perform the shredding function, for example of the flat rotor type, helical rotor with solid screw or soulless screw.
• defibration rotor is in the form of a crown fitted with teeth.
• a person skilled in the art can choose any suitable rotor shape to perform the disintegration function, for example of the flat rotor type with or without bars, helical rotor with solid screw or soulless screw.
• At least one rotor called de-skidding is positioned in a fourth zone called “de-skidding” of the raw material.
• the deflashing rotor present in the fourth zone cannot be assimilated to the defibration rotor formed in the bottom of a conventional pulper.
• the rotor of a conventional pulper works as already explained on raw material of variable size
• the rotor present in the fourth zone of the pulper of the invention works on previously defibrated material and of homogeneous size.
• the deflashing rotor is equipped with finer teeth than those of the defibration rotor. Furthermore, it can also be equipped with holes or protrusions, making it possible to improve, by hydraulic shocks, the de-tacking of the dough. However, a person skilled in the art will be able to choose any form of rotor suitable for performing the deflagging function.
• the spacing of the rotors may vary not only over the same area but also from one area to another.
• the disc can be advantageously replaced by individualized teeth working as a disc would, allowing their easy replacement in the event of damage.
• the axis of the rotor is parallel to the side wall of the tank.
• the axis of the rotor is perpendicular to the side wall of the tank.
• the tank is equipped with rotors with an axis parallel to the side wall of the tank and rotors with an axis perpendicular to the side wall of the tank.
• the tank is equipped with rotors with inclined axes and if necessary with horizontal and / or vertical axes.
• all these rotors can be, for the same axis or separate axes, of the same diameter or of different diameters with similar or very different profiles in order to best adapt to the corresponding work phase.
• the number of rotors is not limited and is determined according to the size of the tank, and the production to be carried out.
• the number of rotors is determined as a function of the distance between the central axis of the tank and the wall thereof, as well as the height of the tank, the defibration energy chosen and the production to be treated.
• the number of rotors is determined as a function of the length of the tank, but also as a function of the width and height of the tank, of the defibration energy chosen and of the production to be processed.
• the tank is oblong in shape and contains at least two rotors, preferably shredding, defibrating and deflashing rotors each mounted on two axes, also designated “shafts", parallel to the wall of the tank, said wall enveloping the '' set of rotors.
• the distance between the wall of the tank and the rotors is reduced so as to minimize the circulation of the raw material and therefore the energy expenditure linked to this circulation.
• the rotors can be mounted on one or more shafts.
• the shredding rotors, the defibration rotors and the raw material stripping rotors are arranged on the same shaft, parallel to the wall of the tank, the shredding rotors being arranged on all the shredding area, the defibration rotors being arranged over the entire defibration zone and the deflashing rotors being arranged over the entire deflagging zone.
• the shredding, defibration and de-sheathing rotors are arranged on different shafts, the shredding rotors being disposed over the entire shredding area, the defibration rotors being disposed over the entire defibration area and the slewing rotors being arranged over the whole slewing area.
• the tank contains several parallel shafts provided with shredding, defibration and de-sheathing rotors, said rotors are advantageously interposed over the entire height of the tank by overlapping.
• the shaft on which the rotor is fixed is held by a horizontal arm integral with the central axis of the tank, substantially at its top, said horizontal arm being rotated by means of a motor.
• said arm is held in a frame formed by two horizontal arms connected to the central axis of the tank, respectively at its top and its base, and by two arms vertical connecting the horizontal arms, the frame being rotated by means of a motor.
• the shaft on which the rotor is fixed is secured to a carriage located at the top of the tank, said carriage being moved in translation by means of a motor.
• the rotors are driven by means of one or more motors positioned, in the case where the rotors move relative to the tank, above said tank.
• the motors driving the rotors are advantageously arranged under the tank, so as to have optimum accessibility at the top of the tank.
• the diameter of the rotors is reduced so as to concentrate the axes on which the rotors are fixed on only part of the surface of the tank, the material first being conducted to the area occupied by the rotors by any known means.
• the raw material is conveyed to the area occupied by the rotors by means of deflectors.
• the axis on which the rotors are fixed is driven by a satellite movement by means of a crown and a toothed zone.
• the energy gain is further increased when the diameter of the rotors occupies the surface of the tank as much as possible, which implies, as already said, that the space between the tank and the rotors, which are then fixed, is reduced .
• a particularly advantageous embodiment is that in which the tank is of oblong shape and envelops at least two rotors each distributed on two vertical axes, the rotors being offset and partially overlapping.
• the bottom of the tank also includes means for evacuating the re-pulped raw material.
• the raw material is discharged at the working concentration of the pulper.
• the evacuation of the raw material is carried out at a lower concentration after dilution.
• the evacuation means are in the form of at least one extraction screw, advantageously two extraction screws.
• the speed of rotation of the screw is adjusted so that it extracts as much raw material re-pulped as raw material and water added to the tank, so that the level of the tank remains constant.
• the discharge means are constituted by a pump, after possible dilution or not of the dough at the bottom of the tank.
• the top of the tank is equipped with partial closing means.
• closure means is in the form of a cover or helmet having an opening intended to ensure the entry of the raw material and of the water into the pulper.
• the helmet or cover is equipped with a helical feeding screw and / or preliminary disintegration to reduce the size of the raw material to disintegrate reaching the pulper itself.
• Figure 1 is a schematic representation of the pulper of the invention according to a first embodiment.
• FIG 2 is a top view of the pulper of Figure 1.
• Figure 3 is a schematic representation of the pulper of the invention according to a second embodiment.
• Figure 4 is a top view of Figure 3.
• Figure 5 is a schematic elevational view in section of a third embodiment of a pulper according to the invention.
• Figure 6 is a top view of Figure 5.
• Figure 7 is a schematic representation of the pulper of the invention according to a fourth embodiment.
• FIG. 8 is a top view of FIG. 7.
• FIG. 9 is a schematic representation of an improved embodiment of FIG. 7.
• FIG. 1 shows the pulper intended for re-pulping of raw material of the paper, cardboard or cellulose type of the invention in a first embodiment according to which the rotors are movable relative to the tank.
• This pulper comprises a cylindrical tank designated by the general reference (1) provided with a central axis (2) and means for discharging the re-pulped material (3).
• the tank (1) comprises at least one rotor (5) mu in rotation around the central axis (2) of the tank.
• the shredding (5a), defibration (5b) and deflashing (5c) rotors are distributed on different vertical axes (4,6,7) in the different zones B, C and D.
• said axes are held inside a frame designated by the general reference (8), consisting of two horizontal arms (9,10), the ends of which are connected by two vertical arms (11,12).
• the frame (8) is rotated about the central axis (2) of the tank by means of a motor (13).
• the frame (8) is made integral with the central axis (2) by any known mechanical means.
• FIG. 2 there is shown, seen from above, the pulper according to FIG. 1.
• the arm (9) is equipped with three axes (4,6,7) supporting the rotors (5), the axes being distributed regularly over the length of the arm (9).
• the arm may include more or less axes equipped with rotors depending on the diameter of the tank, but also on the nature of the raw material to be disintegrated and the production to be treated.
• the axes fitted with rotors (4, 6, 7) are driven in rotation by means of a single motor (14) or of one motor per axis.
• the tank is of generally parallelepiped shape.
• the arm (9) is fixed by each of its ends to a carriage (15), which is moved, by means of a motor not shown, on rails (16).
• the rotors (5) are moved in translation over the entire length of the parallelepiped tank.
• the means of evacuation (3) of the raw material re-pulp are represented in the figure in the form of two extraction screws. These two extraction screws make it possible to keep constant, by adding water and raw material to the top of the tank, the level of said tank, so that the treatment can be carried out continuously when necessary.
• the pulper can process all the fibrous raw materials and the installation can operate discontinuously.
• FIGS 5 and 6 illustrate a third embodiment in which the tank (1) and the rotors (5) are fixed relative to each other, and said tank (1) is generally cylindrical in shape upper (la) and conical in its lower part (lb).
• the displacement of the raw material inside the tank (1) in the direction of the rotors (5) arranged in a central position and three in number is obtained by means of deflectors designated by the same general reference (P). These deflectors will be driven in rotation by a gear motor (M), inside the tank.
• P general reference
• M gear motor
• the deflectors (P) have at their base a solid part (PI) in the shape of a blade and are connected to a frame (C) associated with the gear motor (M) by an openwork structure constituted, in the form illustrated, of connecting bars spaced from each other.
• the tank (1) has a generally oblong shape ( Figure 8) and comprises shredding rotors (5a), defibration (5b) and sheathing rotors (5c) arranged on two vertical axes (4, 6).
• the rotors (5a, b, c) are offset and partially overlap from one vertical axis to the other. The rotors are rotated on themselves by motors (17) arranged under the tank so that access to the raw material in the tank is facilitated.
• the choice of an oblong shaped tank makes it possible to reduce as much as possible the gap existing between the wall (1) and the rotors (5) which makes it possible to reduce the circulation of the raw material and therefore the energy necessary for this circulation. Furthermore, to improve the shearing of the dough, the tank is equipped over the entire height of its walls with stators (18) interposed between the rotors (5a, b, c). Finally and as in the other embodiments, the bottom of the tank is equipped with an extraction screw (3).
• FIG. 9 a pulper similar to that shown in FIG. 7 has been shown but comprising in the hydration zone two screws (18, 19) intended to deconstruct whole bales (22) of raw material and in particular of celluloses before their subsequent introduction into the shredding area.
• these screws are driven in a downward movement and have sharp edges of constant pitch.
• the top (21) of each of the screws has a cone shape for receiving balls of raw material of various sizes.
• the balls are poured between the screws then are gradually destructured thanks to the downward movement of the two screws.
• This system makes it possible to force-feed the pulper regularly with raw material, in other words with a uniform size of raw material. This system therefore has the advantage of reducing the work of the pulper who will no longer have to disintegrate raw material of various sizes.
• the pulper of the invention makes it possible to pulp continuously or discontinuously any type of raw material, whether it is virgin cellulose, old paper, etc., by implementing a consumed energy that is significantly less compared to the pulpers of the prior art, and obtaining a more homogeneous disintegration.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Mechanical Engineering (AREA)
• Paper (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9552416

Family Applications (1)

Country Status (4)

Families Citing this family (3)

Family Cites Families (1)

• 1999
  • 1999-11-23 FR FR9914697A patent/FR2801326B1/fr not_active Expired - Fee Related
• 2000
  • 2000-11-09 AU AU15286/01A patent/AU1528601A/en not_active Abandoned
  • 2000-11-09 EP EP00977640A patent/EP1232303A1/de not_active Withdrawn
  • 2000-11-09 WO PCT/FR2000/003118 patent/WO2001038631A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events