US20150034744A1

US20150034744A1 - Processor with a closed vessel that can be pressurized

Info

Publication number: US20150034744A1
Application number: US14/384,730
Authority: US
Inventors: Hans-Joachim Boltersdorf
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-03-13
Filing date: 2013-03-11
Publication date: 2015-02-05
Also published as: WO2013135224A3; CN104508200A; WO2013135224A2; EP2825697B1; DE112013001451A5; KR20150005520A; EP2825697A2

Abstract

A processor with a closed vessel which can be pressurised and comprises an upper region with a smaller diameter and a lower region with a larger diameter, wherein the upper region comprises a small helix and the lower region comprises a large helix, wherein an admission for materials and one for water are in turn disposed in the upper region and a heavy-part trap is disposed in the lower region.

Description

The invention relates to a processor with an upper region with a smaller diameter and a lower region with a larger diameter, wherein the upper region comprises a small helix and the lower region comprises a large helix, wherein an admission for materials and one for water are in turn disposed in the upper region and a heavy-part trap is disposed in the lower region. This processor can also comprise a closed vessel which can be pressurised. Moreover, the invention relates to a method for operating a pulper.
Various processes are known for processing fibrous raw materials. These processes differ with regard to the degree of recovery of fibrous material, the extraction of fibrous material per unit of time, the quality of fibrous material, the specific power requirement, the heating and auxiliary aid requirements and the specific capital requirement. Even fairly small design changes in the constitution of a processor have a marked influence on these factors. On account of the high quantities of material that are treated with these processors, even minor design changes thus affect the profitability of a processor.
The problem underlying the invention, therefore, is to develop further a processor in such a way that it can perform as many functions as possible and is suitable for different secondary raw materials. Moreover, a method for operating a pulper is provided.
This problem is solved with a processor with the features of claim 1 and with a method with the method steps of claim 19.
Depending on the embodiment, this processor is suitable for the following functions: suspension, sorting, end-stage sorting, fractionation, improving whiteness, grinding and partial de-sanding. Insofar as the processor comprises a heating device, it is even suitable for dispersion. The processor can also operate as a thickener when use is made of a mesh screen.
The processor is suitable in particular for the following secondary materials: fibrous raw materials from the sectors of the paper industry (waste paper processing, paper-making machine, paper processing), dual systems, the industrial economy, the biowaste sector, residual waste recycling and the timber industry.
Moreover, the processor is also suitable for composite materials such as drinks cartons, wallpaper, kraft sack paper, laminated cardboard, posters, photographic paper, nappies and absorber composites, paper-aluminium composites and paper-plastic composites.
Furthermore, it is suitable for the processing of labels, insoles, wet-strength silk tissue paper, filter paper, wet-strength tissue paper, map paper and postage stamp paper. The processing of stripped labels, for example, can be mentioned from the sector of the industrial economy outside the paper industry. PET flakes and DS fractions are mentioned from the dual systems sector and bio-waste from markets and green waste such as in particular grass from the bio-waste sector. Furthermore, the processor is suitable for fibrous raw materials such as for example straw and wood chips.
The processor is suitable for a charge operation or a batch operation, which as a rule is more advantageous than a fully continuous operation.
In the structural embodiment of the processor, it is advantageous if the upper region can be separated from the lower region. Moreover, it is advantageous if the lower region comprises an upper part and a lower part, which are connected detachably to one another in a radially outer region.
An advantageous embodiment makes provision such that a collar is disposed at the upper end of the lower region. The length of this collar acts on the height of the pulper region and makes it possible to configure this height individually. The collar prevents or hinders a backflow from below upwards, i.e. from the lower region into the upper region of the processor. The collar can be constituted simply as a necking. It can however also be constituted as a downwardly tapering cone and behind that a widened section, so that the flow from above downwards is conveyed by the collar and a flow from below upwards is prevented by the collar.
A perforated plate is preferably provided as a separating device. As an alternative, however, a slotted screen, a mesh screen or grid screen can also be provided as a separating device. The mesh screen can be produced here from plastic and/or metal.
Tests have shown that slots which are over 2 mm long and less than 1.2 mm, preferably less than 0.3 mm wide are particularly well suited as a separating device for coarse sorting.
Especially in the case of a bottom plate, it is advantageous if the slots have a longitudinal axis which lies on a straight line which corresponds to a tangent to the rotor motion. If the rotor motion is represented as an arrow direction, the orientation of the slots thus lies roughly in the arrow direction. More detailed investigations have however shown that an orientation of the slots precisely in the orientation of a tangent to the rotor motion does not represent the optimum slot orientation. It is therefore proposed that slots are provided as a separating device whose longitudinal axis lies on a straight line which runs in a horizontal sector of +/−45° to a tangent to the rotor motion. Advantageous results can already be achieved with a deviation of +/−5° to the tangent to the rotor motion.
A corresponding effect can be observed with vertically disposed separating devices. Here too, slots are advantageous whose longitudinal axis lies on a straight line which corresponds to a tangent to the rotor motion on a vertical separating device wall. It is therefore proposed that the slots can also have a longitudinal axis which lies on a straight line which runs in a vertical sector of +/−45° to the tangent to the rotor motion. Here too, even deviations of +/−5° show advantageous results.
The screws can also be used as a liquid guidance device. It is therefore proposed that at least one of the screws comprises a mesh or grid screen. Liquid can be introduced by these screws. However, they are used primarily to take up liquid by suction.
This also makes it possible for at least one of the screws to comprise a hollow body and to be constituted as a separating device.
A particularly preferred embodiment variant makes provision such that the large helix comprises an upwardly pointing end in the radially outer region. This is advantageous especially in the case of basket-like separating devices.
It has emerged that advantageous results are achieved especially when the large helix comprises at least 3 and preferably 5 helix arms.
A particular degree of recovery of fibrous material and a particular quality of fibrous material is achieved by the fact that the diameter of the lower region is at least twice as large and preferably at least three times as large as the diameter of the upper region.
In order to enable continuous processing, it is proposed that the admission for materials enables a feed under excess pressure. A particularly large throughput is thus achieved. Moreover, it has been shown that, as a result of the excess pressure, the sucking-in of air can be avoided and the foam formation is reduced.
If the closed vessel comprises loose bodies made of plastic, these bodies can absorb ink for a deinking process. Alternatively or cumulatively, they can also serve as grinding bodies. A method for operating a processor is particularly advantageous in which materials are made free-flowing in a pulper with a first perforated plate, the larger components are separated out, readily defibrable components are carried away through the perforated plate and the larger components are fed to a processor, in which they are separated by a second perforated plate which has a smaller hole diameter than the first perforated plate.
It is advantageous if long materials and accompanying materials are separated in a first processor in a continuous operation and the accompanying materials are treated charge-wise in a second processor, wherein long materials are separated out in the secand processor and accompanying materials are fed from the second processor via a buffer back to the second processor, wherein the accompanying materials are removed from the circuit after a treatment period.
It is proposed in this regard that the first perforated plate has a perforation diameter of 10 mm or less and the second perforated plate has a smaller hole diameter than the first perforated plate of 2 to 5 mm.
The larger materials can be difficultly defibrable materials and accompanying materials which are preferably transferred via a pump from the pulper into the processor.
For example, approximately 70% (between 50 and 90%) of the materials can run via the pulper, whilst approximately 30% (between 10 and 50%) are fed to the processor. The long material removed from the processor can either be separately recycled or fed to the fibres removed from the pulper preferably after coarse sorting.

Various functions and possible uses of the processor are represented in the drawing and are described in greater detail below. In the figures:

FIG. 1 shows the basic structure of the processor using the example of a suspension process,

FIG. 2 shows the processor shown in FIG. 1 using the example of a pressure sorting process,

FIG. 3 shows the processor shown in FIG. 1 for end-stage sorting,

FIG. 4 shows the processor shown in FIG. 1 for fractionation,

FIG. 5 shows the processor shown in FIG. 1 for grinding,

FIG. 6 shows the processor shown in FIG. 1 for dispersion,

FIG. 7 shows the free fibre stock density as a shred content over time,

FIG. 8 shows a processor circuit for an application of the processor as a pulper disposal unit,

FIG. 9 shows a processor circuit for an application of the processor as a fine sorter,

FIG. 10 shows a processor circuit for an application of the processor for wet-strength wet broke,

FIG. 11 shows a processor circuit for a fully continuous pulper disposal unit,

FIG. 12 shows a processor circuit for an application of the processor as a complete processor,

FIG. 13 shows a processor for waste paper and

FIG. 14 shows a processor with a plurality of lateral chambers.

Processor 1 shown in FIG. 1 is used for the suspension of shreds in the presence of accompanying materials. For this purpose, the processor has a closed vessel 2, which comprises an upper region 3, which has a smaller diameter than lower region 4.
Provided in the upper region 3 is a cover 5, which can seal vessel 2 air-tight and permits vessel 2 to be pressurised.
A small screw 6 is disposed in upper region 3 and a large screw 7 is disposed in lower region 4. Upper region 4 has a first admission 8 for materials 9 and a second admission 10 for water 11.
Provided at the lower end of lower region 4 is a separating device 12, above which a displacer helix 13 is disposed. Located beneath this separating device 12 is outlet 14 for free fibrous material and dissolved matter. This outlet 14 and a material collector 16 disposed upstream are shown in FIG. 2. Moreover, FIG. 2 shows a heavy-part trap 17.
Arrows 18 and 19 in FIG. 1 show how shreds, accompanying materials and free fibrous material are circulated, so that the accompanying materials are carried out via discharge coil 15. Finally, free fibrous material and dissolved matter leave processor 1 via outlet 14, whilst accompanying materials 20 leave the processor via discharge coil 15.
Processor 1 comprises a plurality of parts. Lower region 4 comprises an upper part 21 and a lower part 22, which are connected to one another detachably in a radially outer region 23. At an upper end 24 of lower region 4 is a collar 25, to the upper end 26 whereof upper region 3 is fixed by means of a flange.
In the present case, separating device 12 is a perforated plate. It can however also be constituted by a mesh or grid screen made of plastic or metal.
Whereas FIG. 1 shows the use of the processor for suspension and FIG. 2 shows pressure sorting, FIG. 3 shows end-stage sorting and FIG. 4 fractionation. In the end-stage sorting shown in FIG. 3, starting materials 30 pass according to arrow 29 into the processor and are washed there. Buffer container 27 is then filled via discharge coil 15 according to arrow 20. In a multi-stage process, the processor will run until only very little fibrous material can still be removed at outlet 14. The procedure is then started with new starting material. For this, the processor is first emptied and then filled with new starting material. If buffer container 27 is used as a first in/first out container, the processor can already process new starting materials, while the buffer container is still being pushed empty towards discharge arrow 28. For the processing of beverage packaging, the dirt is first washed out of the shreds in the processor. In the following process step, the shreds are pulped and the fibres are washed out. For the processing of rejects, the fibrous material is first washed out as short material and is then suspended in the processor in order to wash out fibres, in particular long fibres.
It is shown in FIG. 4 that container 2 can be constituted by a special embodiment of separating device 12 with different slot sizes and different downstream regions, in such a way that fibrous materials can be removed in different fibrous material fractions. The separating device with downstream removal points can be constituted in such a way that long and short fibres leave the container in different fibre length fractions. Moreover, the circuit shown in FIG. 4 corresponds to the circuit shown in FIG. 3.
For the treatment of rejects from waste paper, the printing ink has hitherto been chemically dissolved, agglomerated and skimmed off. It is advantageous if the rejects containing the fibres are dis-agglomerated and for the ash to the removed, in order to recover the fibres and dispose of the rest. The agglomerated crumbly stock can be treated with little water on a perforated plate with for example 2 to 2.5 mm in the processor.
A white layer forms on the upper side of the crumbly stock and the black colour pigments migrate downwards towards the perforated plate. The colour pigments and the fillers are washed out in the processor. The fillers form a white layer on the surface and the black colour pigments migrate downwards as sludge. A process for wash-deinking is thus made available with little water, wherein for example 10 l of crumbly stock with 10 to 15% stock density is circulated. Approximately 300 l per hour can thus be processed. A mesh screen in the processor instead of a perforated plate is particularly well suited for deinking.
The use of the processor for grinding is shown in FIG. 5. There, the processor acts as a ball mill, since balls are contained in the starting material which serve as grinding bodies. Provided beneath separating device 12 is a first chamber 30, via which balls can be removed from container 2. For this purpose, a separating device with larger openings, such as for example with holes with a diameter of 6 mm, is provided above chamber 30. When this chamber is opened, balls can pass out of container 2 into chamber 30 and from there can be used further.
Provided beside chamber 30 is a chamber 31, which serves as a further chamber for accommodating fibrous material, said further chamber being able to be disposed at an arbitrary point. For this purpose, a separating device with holes with a diameter of 1.5 mm is provided, for example, above chamber 31. Finally, a chamber 32 is provided as a third chamber, which comprises a plate with holes having a diameter of 1 mm as a separating device and accommodates ball broke.
A particularly preferred method makes provision such that the processor is filled with a material/ball mixture. The processor is first operated in the circuit and water, ball broke and fine material are removed from it via a first chamber. The fibres thus build up in the processor and the material is thickened. The outlet via the first chamber is then closed and the operation is carried out in the circuit with a large quantity of fed water. Another chamber is opened in order to remove fibrous material. The grinding process is thus terminated and many fibres are washed out. The other chamber is then closed and the balls are removed. The accompanying materials are then removed via accompanying material outlet 15 and buffer 27.
FIG. 5 thus shows a processor which serves as any grinding device and in which various chambers 30, 31, 32 for various fractions are provided beneath separating device 12. The processor shown in FIG. 4 is also constituted correspondingly, in order to achieve fractionation with specially adapted separating device dimensions.
FIG. 6 shows how a dispersion can also be carried out by the additional supply of steam 33 in an arrangement such as that shown in FIG. 5.
FIG. 7 shows the change in the free fibre stock density with a treatment of fibrous material in the processing process. Shred content 40 is plotted as a function of time 41. After a short time, the shred content is still very high and the gradient of tangent 42 to curve 43 is still very sharp at approx. 90% shred content. This means that the shred content diminishes very sharply at the start. Gradient 44 with approx. 10% shred content to curve 43 is already very flat and shows that the duration for further defibration becomes ever longer after defibration of the majority of the shreds. This means that as long as the operation is being carried out with a high shred content, a particularly high defibration capacity also results. Upon discharge of the free fibres, the processor should therefore be operated as far as possible in the region of tangent 42 at approx. 90% shred content. A mode of operation in the range between 70 and 95% shred content is advantageous.
The processor can be operated fully continuously according to FIG. 2. Materials 9 and water 11 are continuously fed and heavy parts are continuously removed at heavy-part trap 17, fibrous materials at outlet 15 and accompanying materials 20 out of the processor. In practice, a batch operating mode has emerged as a possible alternative to the charge operation. Here, material 9 and water 11 are fed until an upper level is reached roughly in the region of collar 25. The processor is then operated until the level has dropped into the region of the height of discharge helix 13.
The charge operation with a buffer and accompanying-material return system shown in FIGS. 3 to 6 is however particularly advantageous.
A use of the processor as a pulper disposal unit is shown in FIG. 8. Fibrous material 52 is removed from a pulper 50 as undersize 51, fed to a sorting unit 53 and finally to a paper-making machine 54. From sorting unit 53 or a processing unit and from paper-making machine 54, return water 55 again passes into pulper 50 for the processing of waste paper 56 fed to pulper 50.
Oversize 57 of pulper 50 is fed via coarse material pump 58 to processor 59, which separates the oversize into fibrous material 52 and accompanying materials 60.
The upgrading of the pulper to a fractionator is particular advantageous here. Upstream pulper 55 defibrates only the short material, whereas difficultly defibrable long material is transferred to processor 59 and sorted onwards, i.e. no longer enters into pulper 50. In an example of embodiment, sorting unit 53 comprises a coarse sorting unit and a fine sorting unit, wherein rejects are extracted in each case. The fibrous materials removed from the processor are then fed after the coarse sorting and before the fine sorting to the material flow from pulper 50 to paper-making machine 54.
Instead of pulper 50, use can also be made of a screening drum. The starting material is supplied at the inlet at the other end of an inclined drum. The starting material is then first treated with a great deal of water as it passes through the drum in order to remove short fibres. Then, close to the outlet, less water is added in order to remove longer fibres. The starting material is thus relatively dry at the end of the drum, although water has been added to it in the drum.
An application of the processor as a pressure sorting device is shown in FIG. 9. A pulper 61 with a perforated plate with for example 100 mm through-holes is used there. Oversize 62 is fed to a first processor 63, whilst undersize 64 is fed to a second processor 65. This second processor has a slotted plate with a slot width (or length?) of for example 0.2 to 1.2 mm.
Whereas first processor 63 separates large accompanying materials 66 from fibrous material 67, second processor 65 separates small accompanying materials 68 from fibrous material 69. Fibrous material 67 and 69 can then be further treated together as all-fibre material 70.
The use of the processor for wet-strength wet broke or dry broke is shown in FIG. 10. There, wet broke is fed from a wet broke pulper 71 to a processor. After separation of the accompanying materials, the fibrous materials of processor 72 are fed to a waste paper processing unit 73, from there the fibrous materials migrate into a thickener 74, to machine chest 75 and finally onto screen part 76.
FIG. 11 finally shows a fully continuous disposal of the starting materials pumped away from a pulper. In pulper 80, approx. 96% fibres and 4% accompanying materials are treated on a perforated plate with 8 mm through-holes. Short material 81 is drawn off beneath the screen and the remainder serves as starting material 82 which is pumped by a pump 83 into first processor 84. Long materials 85 and accompanying materials 86 are removed separately from this first processor 84. The accompanying materials pass as rejects 86 into a second processor 87, from which accompanying materials 88 are removed and are fed back via a buffer 89 to second processor 87. Long materials 90 are separated in the second processor.
Buffer 89 is used to receive accompanying materials 88 conveyed in the circuit after a suitable treatment duration and to discharge them from the circuit. While accompanying materials 88 can still be fed to the buffer, new rejects 86 can already be fed to second processor 87.
FIG. 12 shows how starting materials 91 are fed to a two- buffer system 92 a and 92 b. This makes it possible to still fill the one buffer 92 a while the other buffer 92 b is being emptied. Fibrous material 94 is separated in processor 93 via a slotted basket with 0.2 mm, said fibrous material being de-sanded in a hydrocyclone 95. Fibrous material 94 then passes into a thickener 96, from which the liquid fraction passes into processor 93, while the solid phase is made available via a compactor (not shown) as a solid fibre block 97. As is also shown in FIG. 11, accompanying materials 98 conveyed in the circuit are discharged after a suitable treatment time via buffer 99 and, if need be, post-treated with a compactor (not shown). Accompanying materials 98 are preferably conveyed in the circuit until essentially only accompanying materials without fibres are still present in processor 93.
With suitable process management and the use of difficulty defibrable fibrous materials, such as for example wet-strength papers (e.g. labels), the printing ink is the first to leave the processor, i.e. before the bright fibres pass as free fibres through the holes/slots.
The use of mesh screens instead of hole/slot screens is recommended for this. Such screens with almost arbitrary mesh widths also have the property of retaining free fibres. The possibility thus arises of also washing out printing ink from readily defibrable fibrous materials (newspapers and magazines). In a first step, the readily defibrable fibrous material is separated with hole/slot screens from the less readily defibrable fibrous material (brown fractions, in particular sodium paper)—including the mineral oil constituents.
In the deinking process, suitable additives can also be added (chemicals such as for example soda lye or peroxide). The chemicals are first allowed to act so that they can then be washed out.
The processor thus becomes a fibrous material washer and serves to improve the degree of whiteness.
The rotor itself can be constituted as a drainage system. That is to say that it requires a hollow structure with a screen covering. In order to keep the screen of the rotor free, the rotor (bottom helix+lateral wings) should have a very small spacing from the screens of the bottom and the sides.
The processor can thus be operated either with relatively thick fibrous material and slotted plates or more fluidically with a mesh screen. The slotted plates enable perforated plates with finely lasered holes or slots. The mesh screens enable very fine through-holes with a diameter of several μm up to a few millimetres.
The processor with screen fabric can of course also thicken—i.e. remove the water. The dissolved matter as well as the colloids and fillers and fine materials and zero fibres are thereby also washed out.
Processor 100 shown in FIG. 13 is preferably used as a waste paper processor. It has only one helix 101, which however has 5 arms. Beneath helix 101 there is a large screen surface 102, which can be pulled radially outwards and also upwards. Ends 103 of helix 101 are raised somewhat radially outwards. Lower region 104 of processor 100 comprises an upper part 105 and a lower part 104, which are connected to one another detachable in a radially outer region 106. The connection takes place by flange or screws at the radially outermost edge of the lower region. Radial ends 103 of helix 101 extend up to radially outer region 106. A narrow raised helix can thus be used. A stable mixer screw 107 above a screw 109 and a compact design are advantageous. Screw 109 has a relatively large internal diameter. For example, the internal diameter is approximately half that of the external diameter. A free passage area thus arises inside the screw with a cross-section of half the external diameter of the screw. The relative internal diameter can also be relatively still greater. For example, with a screw 109 with an external diameter of 120 cm, the internal diameter can be 100 cm. The screw with the free internal diameter makes it possible, by means of a so-called hollow screw, to move the material in the circumferential direction over a particularly large screen area, without moving a particularly large volume in the vertical direction.
Upper part 105 has a collar 110, which transfers into a feeder region 111. This collar 110 has one or more necking sections 112, which comprise inclined surfaces 113, which enable an inflow from feeder region 111 into lower region 112, but prevent a backflow in the opposite direction.
Moreover, accompanying material outlet 108 is disposed at least above lower region 104 in order to guarantee a pressure in the processor. The inclined surfaces can extend in a spiral manner in the collar region in order to give angular momentum to the fed material, said angular momentum preferably corresponding to the direction of rotation of the mixer screw. The angular momentum can however also be in the opposite direction in order to produce a particular friction in this region.
Waste paper differs from difficultly defibrable paper raw material by the fact that this fibrous material has only a low resistance to defibration.
The described processor offers the possibility of processing readily defibrable fibrous materials in a large quantity. The processor should be operated under a counter- pressure, because otherwise cavitation arises in the perforated plate. Cavitation leads to the formation of water vapour bubbles, which make the screen impassable.
Excess pressure leads to water flows at both openings of the system—accompanying material outlet 108 and the material feed system. The water is therefore conducted away in a targeted manner—with the retention of the accompanying materials and the waste paper—and is pumped back into the inlet line. The targeted backflow in the feed system comprises a level control in the feed funnel. A certain pressure at the accompanying material discharge and at the material feed can be generated by raised lines, which lead to a pressure in the system as a result of the water standing in the line. An advantageous pressure increase can also be achieved by “stuffing”. The material in the line is thereby compressed such that, when the material is fed, the pressure in the processor is increased and, when the accompanying materials are discharged, an escape of water and therefore a reduction of the pressure in the processor is prevented.
In the accompanying material system, a drainage system ensures an adequate water backflow. Moreover, an overflow control ensures that not too much water is fed back, i.e. is withdrawn from the processor.
An almost arbitrary high pressure can thus be generated in the reactor and consequently a very high production of free fibrous material can also be permitted, without the screen closing. Limited only by the rheological transition from laminar into turbulent flow, which would lead to an uncontrollable pressure increase.
The simplicity of the processor is also characterised in that, instead of the known tangential (two-part) accompanying material discharge coil, it comprises a single more or less vertical one. The possibility thus arises of keeping the lower cone small (low) and thus of enabling a large perforated plate diameter with a much freer screen area. The helix arms extend up to the greatest diameter, are kept flat and are provided with more than three arms, in particular with 5 or even 7. This leads to an intensive sweeping action even at low peripheral speeds or rotational speeds.
The shape with relatively sharp transitions diverging from the round shape is essential, said transitions guaranteeing the material flow even with the highest total stock densities. In the cross-section shown, lower region 104 therefore comprises edges with obtuse angles at which the material is broken. The material thus loses its internal consistency and only as a result of this is the ability to be diverted created despite extremely high internal friction.
Waste paper is characterised by a low specific defibration resistance. Consequently, a waste paper processor produces, as is described above, a lot of fibrous material with given dimensions relative to the effective reactor volume. It must be ensured that this fibrous material can leave the reactor by means of a relatively large water flow, without displacing the screen.
A further structure of a processor 120 is shown in FIG. 14. This processor is especially suitable for waste paper and has many advantages.
In the first place: The large free internal diameter of circulation screw 121, which like screw 109 is constituted hollow, occupies a relatively large space and produces a markedly reduced defibration capacity - relative to the external dimensions of the processor.
Secondly, bottom helix 122 has a comparatively small height (less than half the height of the lower region of the pulper) and therefore a small circulation capacity. Depending on the requirement profile, the bottom helix can however also be raised at its radial end (dotted line), in order to change the circulation capacity or the particle guidance. In the example of embodiment, screen basket 123 is essentially disposed in the radially outer regions. It can however extend, also as a basket, additionally over the bottom area. Since the distance between circulation screw 121 and screen basket 123 is relatively small (smaller than half the radius of screw 121), it also requires only a relatively small circulation capacity to maintain the circulation, without so-called bank formation (flow blockades) occurring.
Thirdly, the raised helix keeps the cylindrically disposed screen free. This screen can certainly comprise slots which are disposed at an angle to the axial direction, said angle to be optimised. Thus, for example, horizontal slots or slots which run diagonally to the vertical wall of the screen plate. This enables the passage of fibres through the screen without the retention of the long fibres that is otherwise common. It is advantageous, for example, if the slots run approximately in the flow direction of the material.
Viewed as a whole, the effect of the stated parameters is that, with the upscaling with the increase in the size of the processor by the choice of a greater diameter and a greater height, the arising fibrous material flow (with a given free fibre stock density of, for example, 1%) is controlled, since the available free hole/slot area relative to the reactor volume increases proportionally.

Claims

1. A processor (1) with an upper region (3) with a smaller diameter and a lower region (4) with a larger diameter, wherein the upper region (3) comprises a small screw (6) and the lower region (4) comprises a large screw (7), wherein a first admission (8) for materials (9) and a second admission (10) 5 for water (11) are disposed in the upper region (3), wherein a discharge coil (15) is disposed above a separating device (12) and an outlet (14) for free fibrous material and dissolved matter is disposed beneath the separating device (12).

2. The processor according to claim 1, wherein a large helix is disposed as a displacer helix (13) at the lower end of the large screw (7).

3. The processor according to claim 1, wherein a heavy-part trap (17) is disposed in the lower region (4).

4. The processor according to claim 1, wherein the upper region (3) can be separated from the lower region (4).

5. The processor according to claim 1, wherein the lower region (4) comprises an upper part (21) and a lower part (22), which are connected detachably to one another in a radially outer region (23).

6. The processor according to claim 1, wherein a collar (25) is disposed at the upper end (24) of the lower region (4).

7. The processor according to claim 1, wherein a perforated plate is provided as a separating device (12).

8. The processor according to claim 1, wherein slots are provided as a separating device (12) which are more than 2 mm long and less than 1.2 mm, preferably less than 0.3 mm wide.

9. The processor party according to claim 1, wherein slots are provided as a separating device (12) whose longitudinal axis lies on a straight line which runs in a horizontal or vertical sector of +/−45° to a tangent to the rotor motion.

10. The processor according to claim 1, wherein the large helix comprises an upwardly pointing end in the radially outer region.

11. The processor according to claim 1, wherein the large helix comprises at least 3 and preferably 5 helix arms.

12. The processor according to claim 1, wherein the diameter of the lower region is at least twice as large and preferably at least three times as large as the diameter of the upper region.

13. The processor according to claim 1, wherein the admission for materials enables a feed under excess pressure.

14. The processor according to claim 1, wherein the closed vessel comprises loose bodies made of plastic.

15. A method for operating a processor, in which materials are made free-flowing in a pulper with a first perforated plate, the larger components are separated out, readily defibrable components are carried away through the perforated plate and the larger components are fed to a processor, in which they are separated by a second perforated plate which has a smaller hole diameter than the first perforated plate.

16. The method according to claim 15, in which long materials (85) and accompanying materials (86) are separated in a first processor (84) in the continuous operation and the accompanying materials (86) are treated charge-wise in a second processor (87), wherein long materials (90) are separated out in the second processor (87) and accompanying materials (88) are fed from the second processor (87) via a buffer (89) back to the second processor (87), wherein the accompanying materials (88) are discharged from the circuit after a treatment period.

17. The method according to claim 15, in which the second perforated plate has a smaller hole diameter than the first perforated plate.