HK1201494B - Apparatus for processing plastic material - Google Patents

Description

The invention relates to a device within the meaning of claim 1.

The state of the art has given rise to a number of similar devices of different types, including a receptacle or a cutting compressor for crushing, heating, softening and processing a plastic material to be recycled and a conveyor or extruder connected to it for melting the material so prepared.

For example, EP 123 771 or EP 303 929 describe devices with a reception tank and an extruder attached to it, whereby the plastic material fed to the reception tank is crushed by rotating the crushing and mixing tools and circulated in a drum and heated by the energy supplied at the same time. This results in a mixture with a sufficiently good thermal homogeneity. This mixture is then, after a suitable time, extracted from the reception tank into the screw extruder, and then extruded and plasticized or melted. The screw extruder is placed at about the height of the separation machine. This softening process is actively pushed by the plastic adhesive into the extruder.

EP 1 233 855 B1 discloses a device in accordance with the general concept of claim 1.

Most of these long-established designs are not satisfactory in terms of the quality of the plastic material processed at the end of the shell and/or in terms of the shell's exhaust. Studies have shown that the requirements for the shell following the container, usually a plasticizer shell, are uneven throughout the operation and that this is due to the fact that some batches of the good to be processed remain in the container longer than others. The average shelf life of the material in the container is calculated from the filling weight in the container divided by the shell's output per unit. This container shelf life is - but is not to be mentioned - medium for large parts of the material, which are generally different, such as the amount of oil and oil. These can be caused by the uncontrollable amount of oil and oil in the container, but also by the uncontrollable amount of oil and other residual materials.

For thermally and mechanically homogeneous materials, the quality of the product obtained at the end of the slurry is usually improved by keeping the depth of the slurry measuring zone very high and the slurry rate very low. However, if the emphasis is on an increase in slurry output or an improvement in performance, such as a shredder-extruder combination, the slurry rate must be increased, which means that the cutting rate is also increased. This increases the mechanical and thermal demand on the processed material from the slurry, i.e. there is a risk that the molecular chains of the plastic material will be damaged.

However, in both slow-running and deep-cut snails (high-running depth) and fast-running snails, the different quality of individual parts of the material fed to the snails, as mentioned above, e.g. different flake sizes and/or different temperature of the plastic material, has a negative effect on the inhomogeneities of the plastic material obtained at the snail outlet. In addition, in order to compensate for these inhomogeneities, the temperature profile of the extruder is increased in practice, which means that additional energy must be fed to the plastic, which results in the thermal damage of the plastic material and an increased energy loss. This has reduced the plastic material obtained in the extruder in its thin liquid, which in turn reduces the difficulties of further processing the plastic material.

It follows that the process parameters which are favourable for maintaining good material quality at the slurry outlet are in conflict with each other.

Err1:Expecting ',' delimiter: line 1 column 516 (char 515)

Such systems were therefore generally well-functioning and advantageous, but despite their good functionality and high quality of recyclate, systems with containers or cutting compressors with large diameters, e.g. 1500 mm or more, and longer residence times are not optimally space-saving and efficient or have a high heat dissipation.

The idea of putting the particles in the conveyor direction into the conveyor or extruder was also quite close and corresponded to the conventional notion of the professional, since the conveyor, in particular an extruder, did not have to change its direction of movement and thus no additional direction was needed for the extruder to move. This was done to create a high-speed, even in the case of extrusion, and to increase the radial force of the extruder, which was also used to create a more powerful and more powerful stop in the extrusion process, and to prevent the extrusion of the material from moving through the extrusion process.

Such devices are generally functional and work satisfactorily, although with recurring problems: For example, in the case of materials with a low energy content, such as PET fibres or films, or with an early adhesive or softening point, such as polylactic acid (PLA), it has been repeatedly observed that the effect of deliberately plugging the plastic material into the extruder or conveyor inlet under pressure leads to an early melting of the material immediately after or even in the single-sided area of the extruder or conveyor. This reduces the shredding effect of the conveyor and may also lead to a partial return of this melting into the conveyor or conveyor inlet, which results in the melting of the unfused mixture in a more stable manner, as this usually requires the first complete discharge of the melting mixture and the subsequent discharge of the mixture into the melting mixture, and in such cases the melting process can be completed and the final discharge of the mixture can be stopped and the resulting material can be removed and the mixture can be used in the most stable and stable form, and the resulting mixture can be used in the most difficult cases.

In addition, problems arise with polymer materials that have already been heated in the cutting compressor to close to their melting point, where the recess area is overfilled, the material melts and the recess slows.

Problems also arise with the most stretched, striped, fibrous materials with a certain length extension and low thickness or stiffness, for example with plastic films cut into strips, primarily because the elongated material hangs on the outlet end of the screw opening, with one end of the strip protruding into the receptacle and the other end into the receptacle area. Furthermore, since both the mixing tool and the screw run evenly or apply the same conveyor and pressure-treating components to the material, both ends of the strip are pressurised in the same direction and the pressure is reduced and the cutting force is no longer increased. This can lead to the material being more intensively blocked in this area, and this can lead to problems in the treatment of the material and the further processing of the material in a more efficient manner, resulting in a narrowing of the opening and a further reduction of the pressure and the flow of water through the cutting.

The present invention is intended to overcome the aforementioned disadvantages and to improve a device of the type described at the beginning so that even sensitive or striped materials can be easily removed from the snail and processed or treated with high quality of material, as space-saving, time-efficient and energy-saving as possible and with high throughput.

This problem is solved for a device of the type mentioned at the beginning by the characteristics of claim 1.

This first provides that the intended extension of the central longitudinal axis of the conveyor, in particular the extruder, if it has only one conveyor, or the longitudinal axis of the conveyor nearest the inlet, if it has more than one conveyor, passes opposite the conveyor direction on the rotating axis without cutting it, the longitudinal axis of the conveyor, if it has only one conveyor, or the longitudinal axis of the conveyor nearest the inlet, being displaced one radial axis from the conveyor direction to the outer side of the container, downstream of the longitudinal axis parallel to the three-axis, of the axis of the mixing and/or cutting tool in the conveyor direction.

This means that the direction of the conveyor and the direction of the conveyor are no longer identical, as is known from the state of the art, but at least slightly opposite, reducing the stopping effect mentioned at the beginning. By deliberately reversing the direction of rotation of the mixing and crushing tools compared to previously known devices, the pressure on the inlet area decreases and the risk of overflow is reduced.

This prevents the material from melting in the inlet area, thus increasing operational efficiency, extending maintenance intervals and reducing downtime due to any repairs and cleaning measures.

The reduction in the discharge pressure makes the slides which are known to regulate the filling rate of the slug much more sensitive and the filling rate of the slug even more precise, making it easier to find the optimum operating point of the system, especially for heavier materials such as high-density polyethylene (HDPE) or PET.

It has also been found to be surprisingly advantageous that materials which have already been softened to close to the melt are better absorbed in the reverse operation according to the invention. In particular, when the material is already in a malleable or softened state, the screw cuts the material from the malleable ring which is adjacent to the wall of the container.

In addition, when working the striated or fibrous materials described above, the deposits or accumulations formed can be more easily dissolved or not formed at all, since on the edge in the direction of rotation of the mixing tools, on the downstream or downstream edge of the opening, the direction vector of the mixing tools and the direction vector of the conveyor show almost opposite or at least slightly opposite directions, so that a longer strip cannot bend and deposit around this edge, but is torn away by the mixing drum in the reception tank.

This behaviour of the device is supported by the presence on the inside wall surface of the container of at least one rod-shaped indicator, which is directed towards the inside of the container, the height of which decreases from top to bottom in the direction of rotation of the mixing tool and includes a sharp angle along its length with a plane perpendicular to the axis of rotation of the mixing tools.

Overall, the design according to the invention improves the inlet behaviour and significantly increases throughput, making the overall system of cutting compressors and conveyors more stable and efficient.

This specific design of a cutting compressor-conveyor system makes it possible to use smaller-diameter containers or cutting compressors, contrary to previous expectations, and to achieve high throughput and output even with shorter residence times.

Due to the gentle retraction of the slug due to the opposite rotation of the mixing tools, more aggressive tools can be used in the cutting compressor, which provide more energy to the material. This also reduces the average residence time of the material in the cutting compressor. The cutting compressor can therefore be operated at a higher temperature, which in turn results in better homogeneity. The material can therefore also be well prepared in containers with smaller diameters and residence times.

In addition, such a combination of cutting compressor and extruder unexpectedly improves the material's entry and melting performance in a connected extruder, thus compensating for any inhomogeneities and giving the material entering the shell casing from the container and then compressed and melted a high degree of thermal and mechanical homogeneity. Accordingly, the final quality of the plastic or aggregate at the extruder or aggregator end is very high and shells can be used which, due to the high processing and the preferential insertion, can handle the already treated material and bring particularly little shell into a polymer to melt this material.

In order to adapt to different materials and fill volumes, the invention may provide that the angle over the length of the projector is at least partially constant or that the projector is curved over at least a portion of its length, particularly downward, in which case the angle is the tangential angle at the respective point of the projector and/or that the angle, especially in the middle area of the projector, is 15° to 45°, preferably 20° to 40°, and/or that the angle to the lower end of the projector decreases, if necessary to an angle α = 0°.

To assist the slurry in intake behaviour and material entry into the intake opening, it has been shown to be advantageous if the lower end of the projector is located in a perimeter area of the container between the two lateral edges of the intake opening and this area is enlarged, if necessary in the direction of rotation of the tools, by a maximum of 50% to 80% of the length of a longitudinal edge and/or if the lower end of the projector is located at a height level to the container wall, which is in the area between the upper and lower longitudinal edges of the intake opening and, if applicable, a maximum of 50% to 80% of the height of the upper longitudinal opening or a maximum of 20% to 30% of the height of the unit of the opening, below the edge of the intake opening/opening, or if the device is located at least 15° to the upper edge of the rotation, or at a height of the unit of the opening, if it is located at a distance of 15° or 30° from the edge of the entrance, or at least 55° to the opposite edge of the rotation, when the device is placed in the direction of rotation, and, if necessary, at a maximum of 20% to 30% of the height of the unit of the opening.

The rod-shaped indicator may be provided with a rectangular cross-section, preferably rounded at the edges protruding in the container, and shall be fixed with its narrow side to the inner wall of the container.

The width and length of the strippers may be adapted to the type of materials and their treatment and the desired insertion behaviour, and the width of the stripper may be increased towards the end or reduced, where appropriate in stages.

It is advantageous if the width of the rejector is between 1% and 10% of the diameter of the container.

A special design of the ejector may provide for the addition of an extension, in particular a single extension, to the lower end, which is the lowest part of the ejector and which is oriented upwards in the direction of rotation, in particular to improve the flow of material down the direction of rotation of the inlet.

It has been shown that the end of the reflector outside the light cross section of the intake opening is beneficial for the intake behaviour.

The following features describe other advantages of the invention: The device is particularly advantageous when the constant K is in the range 90 to 170. At these K values and the corresponding container sizes and residence times, the tool transmits the material to the conveyor particularly efficiently and the partially opposite characteristics of container size, residence time, inlet behaviour or flow rate and the quality of the final product are well balanced.

According to a further development of the invention, the conveyor is arranged on the reception vessel in such a way that the scalar product is oriented from tangential to the plane of the radial outermost point of the mixing and/or crushing tool or to the plastic material passing through the opening and normally to a radial of the reception vessel, in the direction of rotation or movement of the mixing and/or crushing tool (directional vector of rotation) and the directional vector of the reception vessel at each point or in the entire area of the opening or at each point or in the entire area immediately before the opening, radially zero or negative.In particular, the spatial arrangement of the mixing tools and the screw does not depend on the spatial arrangement of the screw, for example the axis of rotation does not have to be oriented normally to the ground surface or to the longitudinal axis of the conveyor or the screw. The directional vector of the direction of rotation and the directional vector of the conveyor are in a normal, preferably horizontal, or in a plane oriented normally to the axis of rotation.

Another advantage is that the directional vector of the direction of rotation of the mixing and/or crushing tool includes an angle greater than or equal to 90° and less than or equal to 180° with the directional vector of the conveyor, measured at the intersection of the two directional vectors at the edge of the opening upstream of the direction of rotation or movement, in particular at the point furthest upstream of this edge or opening. This describes the angle range in which the conveyor must be positively arranged at the receiving end of the conveyor to achieve the desired effects.

A further advantageous design of the invention is that the directional vector of the direction of rotation or motion with the directional vector of the conveyor direction includes an angle between 170° and 180°, measured at the intersection of the two directional vectors in the centre of the opening.

To ensure that no excessive stopping effect occurs, it may be advantageous to provide that the distance or displacement of the longitudinal axis to the radial is greater than or equal to half the inner diameter of the conveyor or check case.

In this respect, it may also be advantageous to measure the distance or displacement of the longitudinal axis to the radials greater than 5 or 7%, or even greater than 20%, of the radius of the reception vessel. In the case of conveyors with an extended inlet area or a nut case or an extended pocket, it may be advantageous if this distance or displacement is greater than or equal to the radius of the reception vessel.

The outermost passages of the snail do not protrude into the container.

This is particularly advantageous if the conveyor or the conveyor-beam or the conveyor-beam nearest to the inlet or the inner wall of the housing or the casing of the check is tangential to the inside of the side wall of the container, preferably with the conveyor-beam on its front side connected to a drive and on its opposite front side to an exit opening, in particular an extruder head, located on the front of the housing.

In the case of conveyors which are radially displaced but not tangentially arranged, it is advantageous to provide that the intended extension of the conveyor's longitudinal axis in the direction of conveyance passes through the interior of the reception vessel at least in secant form.

It is advantageous to provide that the opening is connected to the inlet opening directly and directly and without any longer distance or transfer distance, e.g. a conveyor belt, allowing for an efficient and gentle transfer of material.

The reversal of the direction of rotation of the mixing and crushing tools in the container cannot be done by accident or accident, and neither in the case of the apparatus known nor in the case of the apparatus of the invention can the mixing tools be made to rotate in the opposite direction without further delay, especially because the mixing and crushing tools are arranged in a certain way asymmetrically or directionally so that they act only on one side or in one direction. If such an apparatus were deliberately rotated in this direction, neither a good mixing drum would be formed nor the material would be sufficiently crushed or heated. Each has thus fixed its own direction of rotation and cutting of the mixing and crushing machine.

In this context, it is particularly advantageous to provide that the front and front axes of the mixing and/or shredding tools acting on the plastic material in the direction of rotation or movement are differently formed, curved, positioned or arranged compared to the rear and rear axes in the direction of rotation or movement.

A favourable arrangement is to arrange on the mixing and/or shredding tool tools and/or blades which act on the plastic material in a rotational or motion direction to heat, shred and/or cut. The tools and/or blades may be either directly attached to the shaft or preferably mounted on, or formed or shaped into, a rotating tool holder or a supporting disc, especially parallel to the floor surface.

In principle, the effects mentioned are relevant not only for compressing extruders or agglomerators, but also for no-compressing or less compressing conveyor slugs.

Another particularly advantageous design provides that the reception tank is essentially cylindrical with a flat floor surface and a cylindrical sidewall oriented vertically to it. It is also simpler in design when the rotation axis coincides with the central axis of the reception tank. Another advantageous design provides that the rotation axis or the central axis of the reception tank is oriented vertically and/or normally to the floor surface. This particular geometry optimizes the intake behaviour in a structurally stable and easily constructed device.

In this context, it is also advantageous to provide that the mixing and/or crushing tool, or, if several mixing and/or crushing tools are provided in a stack, the lowest, nearest to the ground mixing and/or crushing tool, and the opening are placed at a short distance from the floor, in particular in the lower quarter of the height of the reception tank. The distance is defined and measured from the bottom edge of the opening or intake opening to the bottom of the tank in the periphery of the tank. Since the corner edge is usually rounded, the distance from the edge of the opening of the intended extension to the bottom of the tank is measured at a distance of approximately 400 mm from the intended extension to the outer edge of the tank.

It is also advantageous for machining if the radial outermost edges of the mixing and/or shredding tools reach close to the sidewall.

In this context, it is particularly advantageous if the distance A of the radial outermost point of the lowest mixing and/or crushing tool or the distance A of the circumference of this point from the inner surface of the sidewall of the container is greater than or equal to 20 mm, in particular between ≥ 20 mm and 60 mm, resulting in a particularly effective and gentle recruitment behaviour.

The container need not necessarily be cylindrical, although this is advantageous for practical and manufacturing reasons. Container shapes which differ from the circular shape, such as conical or cylindrical containers with an elliptical or oval base, must be converted into a cylindrical container of the same volume of barrel, assuming that the height of this fictitious container is equal to its diameter. Heights of containers which are significantly higher than the resulting mixing drum (taking into account the safety distance) are not taken into account, as these containers are therefore not overheated and no longer affect the material used.

The term 'conveyor' here refers to both systems with non-compressing or decompressing conveyor belts, i.e. pure conveyor belts, and systems with compressing belts, i.e. extruder belts with an agglomerating or plasticizing effect.

For the purposes of this Regulation, the term 'extruder' or 'extruder slug' means both extruder or slug used to fully or partially melt the material and extruder used only to agglomerate the softened material but not to melt it. In the case of aggregate slug, the material is only briefly compressed and sheared, but not plasticized. The aggregate slug therefore produces at its output a soft material which is not fully melted but consists only of slugs fused at its surface, which are baked together as part of a sintering process. In both cases, however, pressure is applied to the material via the slug and this material is compacted.

The examples given in the following figures show conveyors with a single conveyor, e.g. single-wave or single-wave extruders, but alternatively conveyors with more than one conveyor, e.g. double- or multi-wave conveyors or extruders, in particular with several identical conveyors having at least the same diameter d, may be provided.

Further features and advantages of the invention are shown by describing the following non-limiting examples of the subject matter of the invention, which are shown in the drawings in a schematic and non-scale manner: Figure 1 shows a vertical cut by a device according to the invention with an extruder connected tangentially.Figure 2 shows a horizontal cut by the embodiment of Figure 1.Figure 3 shows another embodiment with minimal displacement.Figure 4 shows another embodiment with greater displacement.Figures 5 and 6 show a container with rejectors.Figure 7 shows a detail.Figures 8 to 10 show schematically the arrangement and training of rejectors.

For the sake of clarity, the indicators are merely indicated in Figures 1, 3 and 4.

The design of the containers, the snails and the mixing tools is not in scale, either as such or in relation to each other.

The advantageous cutting compressor-extruder combination for processing or recycling plastic material shown in Figures 1 and 2 has a cylindrical container or cutting compressor or shredder 1 with a flat horizontal floor area 2 and a normally oriented vertical cylindrical sidewall 9.

At a small distance from floor 2, at a maximum height of about 10 to 20 per cent, or less if applicable, of the sidewall 9 - measured from floor 2 to the upper edge of the sidewall 9 - is a flat support disc or tool holder 13 aligned parallel to floor 2 which is arranged around a central pivot axis 10 which is also the central axis of the container 1 into which the direction of rotation 12 marked by an arrow 12 can be attached. The support drive 13 is driven by a 21 motor located below the container 1. On the top of the support disc 13 are the cutters or cutters, which together with the supporting disc 13 and the cutting tool 13 form the 14 small cutters.

As shown in the diagram, the blades 14 on the supporting disc 13 are not symmetrically arranged but are specially trained, positioned or arranged on their front edges 22 pointing in the direction of rotation or movement 12 to have a specific mechanical effect on the plastic material.

The container 1 has a filling opening at the top through which the product to be processed, e.g. portions of plastic foil, is thrown in towards the arrow, e.g. by means of a conveyor. Alternatively, container 1 may be closed and evacuated to at least a technical vacuum, with the material being introduced via a locking system. This product is captured by the circulating mixing and/or shredding tools 3 and rotated upwards in the form of a mixing drum 30, whereby the product is raised along the vertical sides 9 and crushed upwards in the area of the mixing container by gravity and back downwards in the area of the mixing container 12 without any further movement. The height of the mixing device 1 is not to be adjusted in the direction of its movement, and therefore the material can only be rotated upwards in the direction of its movement, either from the top or the bottom, without any special adjustment of the height of the mixing device 12 or 12 and without any further adjustment of the height of the mixing device 12 or 12 and therefore the material can only be rotated in the opposite direction of the mixing device 12 or 12 due to the special adjustment of the mixing device 12 and 12 and 12 respectively.

The plastic material is crushed, mixed and heated and softened by the mechanical friction energy applied, but not melted, by the circulating mixing and shredding tools 3 and after a certain period in container 1, the homogenised, softened, but not melted, ductile material, as discussed in detail below, is released from container 1 through an opening 8 and brought into the intake area of an extruder 5 where it is collected by a snail 6 and subsequently melted.

At the level of the single crushing and mixing tool 3 in the present case, the opening 8 is formed in the sidewall 9 of tank 1 through which the pre-treated plastic material can be extracted from the inside of tank 1. The material is passed to a single-screw extruder 5 located tangentially on tank 1, the housing 16 of the extruder 5 having a cowl opening 80 in its casing for the material to be extracted from the screw 6. Such an embodiment has the advantage that the screw 6 can be extracted from the bottom of the screw in Figure 6 by only a widely represented drive, so that the drive in the upper part of the screw is extracted from the screw without the use of a screw engine. This is not possible for plastic material, which is not cut in the shape of the screw 6 shown in Figure 3 or 6 and therefore cannot be extracted from the top of the screw without the use of a screw driven by the screw driven by the screw.

The intake opening 80 is connected to opening 8 for the conveyance or transfer of materials and is in this case directly, directly and without any longer interval or distance connected to opening 8 and only a very short transfer area is provided.

In case 16, a compressing slug 6 is stored rotatively around its longitudinal axis 15. The longitudinal axis 15 of slug 6 and extruder 5 converge. Extruder 5 moves the material in the direction of the arrow 17. Extruder 5 is a well-known conventional extruder in which the softened plastic material is compressed and thereby melted down, and the melt is then released on the opposite side at the extruder head.

The mixing and/or crushing tools 3 and the cutters 14 are at approximately the same height and level as the central longitudinal axis 15 of the extruder 5.

In the embodiments shown in Figures 1 and 2, the extruder 5 is connected tangentially to the container 1 or runs tangentially to its cross section, as mentioned above. The intended extension of the central longitudinal axis 15 of the extruder 5 or the screw 6 in the direction of conveyance 17 of the extruder 5 to the rear passes in the drawing next to the rotation axis 10 without cutting it. The longitudinal axis 15 of the extruder 5 or the screw 6 is parallel to the longitudinal axis 15 of the mixing and/or separation tool 3 in the direction of conveyance 17 of the extruder 5 to the outer radial axis 11 of the extruder 1 by 18 knots. In the present case, the extension of the screw 5 of the extruder 1 is not directed in the direction of conveyance 15 but in the direction of the extruder 5 to the outer radial axis 11 of the extruder 1.

The distance 18 is slightly larger than the radius of the container 1. This slightly displaces the extruder 5 outwards or the intake area is slightly lower.

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In other words, the scalar product is composed of a directional vector 19 of the direction of rotation 12 tangential to the circumference of the outermost point of the mixing and/or crushing tool 3 or tangential to the plastic material passing through the opening 8 and having a direction of rotation 12 of the mixing and/or crushing tool 3 and a directional vector 17 of the extruder's direction of delivery 5 parallel to the central longitudinal axis 15 in the direction of delivery at each point of the opening 8 or in the radial area immediately in front of the opening 8, everywhere negative or positive, but nowhere positive.

In the inlet aperture in Figures 1 and 2, the scalar product from the direction vector 19 of the direction of rotation 12 and the direction vector 17 of the direction of conveyance at each point of the aperture 8 is negative.

The angle α between the direction vector 17 of the conveyor and the direction vector 19 of the rotor, measured at the point 20 of aperture 8 and at the edge of aperture 8 which is the furthest upstream of the direction of rotation 12, is approximately 170°.

If you go downwards along the opening 8 in Fig. 2 in the direction of rotation 12, the blunt angle between the two directional vectors will become larger and larger. In the middle of the opening 8 the angle between the directional vectors is about 180° and the scalar product is at its maximum negative, further below it the angle even becomes > 180° and the scalar product decreases slightly again, but always remains negative.

An angle β between the direction vector of the direction of rotation 19 and the direction vector of the direction of conveyance 17 measured at the centre or centre of the opening 8 and not shown in Fig. 2 is approximately 178° to 180°.

The device described in Figure 2 represents the first limit or extreme value. Such an arrangement allows for a very gentle stopping effect or a particularly advantageous feed and is particularly advantageous for sensitive materials which are processed near the melting point or for long-range goods.

Figure 3 shows an alternative embodiment in which the extruder 5 is not tangential but is connected to the container 1 by its front side 7. The screw 6 and the housing 16 of the extruder 5 are aligned and repositioned at the bottom to the outline of the inner wall of the container 1 in the area of the opening 8. No part of the extruder 5 protrudes through the opening 8 into the interior of the container 1.

The distance 18 corresponds here to about 5 to 10% of the radius 11 of the container 1 and about half the inner diameter d of the housing 16. This embodiment thus represents the second limit or extreme value with the smallest possible shift or distance 18 in which the direction of rotation or movement 12 of the mixing and/or crushing tools 3 is at least slightly opposite to the conveyor direction 17 of the extruder 5 over the entire area of the opening 8.

The scalar product is exactly zero in Fig. 3 at the limiting point 20 at the furthest upstream point 20 at the furthest upstream edge 20' of aperture 8. The angle α between the direction vector 17 of the conveyor direction and the direction vector 19 of the rotation direction is exactly 90° as measured in Fig. 3. If one goes downwards along aperture 8, i.e. in direction 12, the angle between the direction vectors increases and becomes a blunt angle > 90° and the scalar product simultaneously. At no point or in no region of aperture 8 can the scale product or the angle be positive or negative than 90°.

It is also a crucial difference from a purely radial arrangement, since at point 20 or at the edge 20', if the extruder 5 were fully radial, there would be an angle α < 90° and those areas of the opening 8 which are above radials 11 or upstream or downstream in the drawing would have a positive scalar product, so that local molten plastic material could accumulate in these areas.

In Fig. 4 another alternative embodiment is shown, in which the extruder 5 is slightly further out than in Fig. 3 but not yet tangential as in Fig. 1 and 2. In this case, as in Fig. 3, the rearward-facing extension of the longitudinal axis 15 of the extruder 5 penetrates the interior of the container 1 in a secant fashion. This results in the opening 8 being wider than in the embodiment of Fig. 3 as measured in the perimeter of container 1. The opening 18 is also correspondingly larger than in Fig. 3, but slightly smaller than the radius 11.

In order to achieve optimal conditions for the residence times of the plastic in all these container-extruder combinations for pre-gilding, pre-drying and preheating of the plastic material in container 1, the diameter D of container 1 is related to the outer diameter d of the slurry 6. $D=10.\sqrt[3]{K\mathrm{.}{d}^2},$ where D is the inside diameter of the container 1 in millimetres, d is the diameter of the screw 6 in millimetres and K is a constant, which is in the range 60 to 180.

As mentioned above, the specific ratio between the inner diameter D of tank 1 and the average diameter d of the shell 6 ensures, at relatively short average residence times of the material, that the inlet 80 of the housing 16 always receives goods of sufficiently constant thermal and mechanical properties, even if the goods to be processed are difficult to process, e.g. film residues of different properties (thickness, size, etc.). The mixing machine or shredding machine 3 ensures, by means of its special rotary direction 12 relative to the direction of the cutting axes 6 that the material already being injected into the extruder is always injected and ensures that, at high throughput, a homogeneous alloy of materials is obtained.

Figure 5 shows a schematic section through a container 1 in which two indicators 50 are placed on opposite inner wall areas. One indicator 50 is opposite the inlet 80; the other indicator, which has an end-extension 57, has a lower end area or a lower end area 58, which is above the inlet 80 respectively.

Figure 6 shows an overview of the container shown in Figure 5.

Figure 7 shows a detailed section of the connection of a conveyor or extruder nozzle 6 to the container 1. Above the inlet opening 80 is a reflector 50. This rod-shaped reflector 50 is fixed to the container wall with its narrow side and protrudes into the container.

The projector 50 is designed to have a height gradient, the height level of which decreases from top to bottom in the direction of rotation 12 of the mixing tool 3 as shown in Figures 8 and 9, whereby each projector 50 includes at least for most of its length a sharp angle α with a plane E, which plane E is perpendicular to the axis of rotation 10 of the rotating mixing and shredding tools 3.

The projector 50 may extend along the inner wall of the container at a constant angle α in the form of a straight line. It is self-evident that the projector 50 follows the inner wall of the container and, in view of this, as shown in Figure 6, has a corresponding curvature along the perimeter of the container. However, the angle α is measured with respect to the plane E and, if a projector 50 has a curvature over its height, the respective tangential angle α at the points considered of the projector 50 may be used as the angle α.

It is advantageous if, as shown in the figures, at least over a section of the projector 50 the angle α is 15° to 45°, preferably 20° to 40°.

It is clear from Figures 8 and 9 that the height of the projector 50 is usually a convex curve directed against the direction of rotation 12 of the tool 3.

Figure 8 shows a large number of indicators of different lengths and/or heights 50. Figure 8 also shows that the direction of rotation 12 of tool 3 is directed against the direction of conveyance FS of the screw 6, as explained in detail in Figures 1 to 4. Figure 8 shows the area 70 surrounding the inlet 80 area.

It shall be provided that the lower end of the projector 50 is in a perimeter area of the container wall between the two side edges 55, 56 and the inlet 80 and that this area is enlarged, if necessary in the direction of rotation of the tools 3, by a maximum of 50% to 80% of the length of a longitudinal edge 52, 53.

In addition, it is provided that the lower end of the projector 50 is at a level which lies in the range 70 between the upper and lower longitudinal edge 52, 53 of the inlet 80 and, where applicable, is not more than 50% to 80% of the height HE of the inlet 80 above the upper longitudinal edge 52 or not more than 20% to 30% of the height HE of the inlet 80 below the lower edge 53 of the inlet 80.

For the upper ends of the indicators, the upper end of the indicator 50 may be positioned facing the direction of rotation 12 of the mixing tool 3 at least 10° to 15°, preferably 30° to 55°, before the upward edge 56 of the inlet 80 or after the downward edge 55 of the inlet 80; this position of the indicator 50 will greatly improve the inlet behaviour.

The width b and the length I of the marker 50 can be adjusted and specified as shown in Fig. 10. In Fig. 10 a marker 50 with a rectangular cross-section is shown. Next to it on the right is the marker 50 which expands or spreads towards its lower end 58 in its last section. The marker shown on the right has different widths b over its length I or is blunted in its end range.

It is possible that several indicators 50 may terminate in the range of the inlet 80; preferably, the ends 58 of indicators 50 are in a perpendicular to the edge 52 radius 70 and terminate at or below the height of edge 52.

The other tell-tales 50 in container 1 located away from the inlet opening (80) may have the same characteristics, in particular as regards height and level, as the tell-tales 50 located within the scope of the inlet opening 80.

Claims (16)

1. Apparatus for the pretreatment and subsequent conveying, plastification or agglomeration of plastics, in particular of thermoplastics waste for recycling purposes, with a container (1) for the material to be processed, where the arrangement has, in the container (1), at least one mixing and/or comminution implement (3) which rotates around an axis (10) of rotation and which is intended for the mixing, heating and optionally comminution of the plastics material, where an aperture (8) through which the pretreated plastics material can be removed from the interior of the container (1) is formed in a side wall (9) of the container (1) in the region of the level of the, or of the lowest, mixing and/or comminution implement (3) that is closest to the base, where at least one conveyor (5), in particular one extruder (5), is provided to receive the pretreated material, and has at least one screw (6) which rotates in a housing (16) and which in particular has plastifying or agglomerating action, where the housing (16) has, located at its end (7) or in its jacket wall, an intake aperture (80) for the material to be received by the screw (6), and there is connection between the intake aperture (80) and the aperture (8), where the imaginary continuation of the central longitudinal axis (15) of the conveyor (5) or of the screw (6) closest to the intake aperture (80), in a direction opposite to the direction (17) of conveying of the conveyor (5), passes, and does not intersect, the axis (10) of rotation, characterized in that, on the outflow side in the direction (12) of rotation, there is an offset distance (18) between the longitudinal axis (15) of the conveyor (5) or of the screw (6) closest to the intake aperture (80), and the radius (11) that is associated with the container (1) and that is parallel to the longitudinal axis (15) and that proceeds outwards from the axis (10) of rotation of the mixing and/or comminution implement (3) in the direction (17) of conveying of the conveyor (5), and in that, on the internal wall area of the container (1) there is at least one bar-shaped deflector (50) which is directed into the interior of the container (1), and the height profile of which decreases in the direction (12) of rotation of the mixing implement (3), seen from above, and the angle included thereby, over its length, with a plane (E) perpendicular to the axis (10) of rotation of the mixing implements (3) is an acute angle (α).
2. Apparatus according to Claim 1, characterized in that the angle (α) is constant at least in sections over the length of the deflector (50), or that the profile of the deflector (50) is curved, in particular curved downwards, at least over a section of its length (I), and in that case the angle (α) represents the tangential angle present at the respective point on the deflector (50).
3. Apparatus according to Claim 1 or 2, characterized in that the angle (α), in particular in the central region of the deflector (50), is from 15° to 45°, preferably from 20° to 40° and/or that the angle (α) decreases towards the lower end of the deflector (50), optionally to an angle α = 0°.
4. Apparatus according to any of Claims 1 to 3, characterized in that the lower end (58) of the deflector (50) is within a circumference (70) between the two lateral edges (55, 56) of the intake aperture (80), and this region is optionally enlarged in the direction of rotation of the implements (3) only by at most from 50% to 80% of the length of a longitudinal edge (52, 53) and/or that the lower end (58) of the deflector (50) is at a height level on the container wall, where this level is within the region (70) between the upper and lower longitudinal edge (52, 53) of the intake aperture (80) and optionally at most from 50% to 80% of the height (HE) of the intake aperture (80) above the upper longitudinal edge (52) or at most from 20% to 30% of the height (HE) of the intake aperture (80) below the lower edge (53) of the intake aperture (80).
5. Apparatus according to any of Claims 1 to 4, characterized in that the deflector (50) protrudes radially from the internal wall of the container and/or that the bar-shaped deflector (50) has a rectangular cross section optionally rounded at the edges projecting into the container (1), and is secured by its narrow side on the internal wall of the container (1).
6. Apparatus according to any of Claims 1 to 5, characterized in that the width of the deflector (50) optionally decreases in stages in the direction towards the end, or that the deflector (50) is widened in the end region and/or that viewed in the direction (12) of rotation of the mixing implements (3), the upper end of the deflector (50) is at least 10° to 15°, preferably 30° to 55°, prior to that edge (56) that is associated with the intake aperture (80) and that is situated upstream in the direction of rotation, or after that edge (55) that is associated with the intake aperture (80) and that is situated downstream in the direction of rotation.
7. Apparatus according to any of Claims 1 to 6, characterized in that the width (b) of the deflector (50) is in the range from 1% to 10% of the diameter of the container, and/or that the width of the deflector (50) is greater than 15 mm, preferably from 20 to 250 mm.
8. Apparatus according to any of Claims 1 to 7, characterized in that the lower end representing the lowest section (58) of the deflector (50) is followed by an extension (57), which is directed upwards in the direction (12) of rotation, in particular as a single piece and/or that the deflector (50) ends outside of the open cross section of the intake aperture (80).
9. Apparatus according to any of Claims 1 to 8, characterized in that, for a conveyor (5) in contact with the container (1), the scalar product of the direction vector that is associated with the direction (19) of rotation and that is tangential to the circle described by the radially outermost point of the mixing and/or comminution implement (3) or that is tangential to the plastics material transported past the aperture (8) and that is normal to a radial (11) of the container (1), and that points in the direction (12) of rotation or of movement of the mixing and/or comminution implement (3) and of the direction vector (17) that is associated with the direction of conveying of the conveyor (5) at each individual point or in the entire region of the aperture (8) or immediately radially prior to the aperture (8) is zero or negative.
10. Apparatus according to any of Claims 1 to 9, characterized in that the angle (α) included between the direction vector that is associated with the direction (19) of rotation of the radially outermost point of the mixing and/or comminution implement (3) and the direction vector (17) that is associated with the direction of conveying of the conveyor (5) is greater than or equal to 90° and smaller than or equal to 180°, measured at the point of intersection of the two direction vectors (17, 19) at the inflow-side edge that is associated with the aperture (8) and that is situated upstream in relation to the direction (12) of rotation or of movement of the mixing and/or comminution implement (3), in particular at the point (20) that is on the said edge or on the aperture (8) and is situated furthest upstream.
11. Apparatus according to any of Claims 1 to 10, characterized in that the angle (β) included between the direction vector (19) that is associated with the direction (12) of rotation or of movement and the direction vector (17) that is associated with the direction of conveying of the conveyor (5) is from 170° to 180°, measured at the point of intersection of the two direction vectors (17, 19) in the middle of the aperture (8).
12. Apparatus according to any of Claims 1 to 11, characterized in that the distance (18) is greater than or equal to half of the internal diameter of the housing (16) of the conveyor (5) or of the screw (6), and/or greater than or equal to 7%, preferably greater than or equal to 20%, of the radius of the container (1), or in that the distance (18) is greater than or equal to the radius of the container (1) or that the imaginary continuation of the longitudinal axis (15) of the conveyor (5) in a direction opposite to the direction of conveying is arranged in the manner of a secant in relation to the cross section of the container (1), and, at least in sections, passes through the space within the container (1) or that the conveyor (5) is attached tangentially to the container (1) or runs tangentially in relation to the cross section of the container (1), or in that the longitudinal axis (15) of the conveyor (5) or of the screw (6) or the longitudinal axis of the screw (6) closest to the intake aperture (80) runs tangentially with respect to the inner side of the side wall (9) of the container (1), or the inner wall of the housing (16) does so, or the enveloping end of the screw (6) does so, where it is preferable that there is a drive connected to the end (7) of the screw (6), and that the screw provides conveying, at its opposite end, to a discharge aperture which is in particular an extruder head and which is arranged at the end of the housing (16).
13. Apparatus according to any of Claims 1 to 12, characterized in that there is immediate and direct connection between the aperture (8) and the intake aperture (80), without substantial separation, in particular without transfer section or conveying screw.
14. Apparatus according to any of Claims 1 to 13, characterized in that the mixing and/or comminution implement (3) comprises implements and/or blades (14) which, in the direction (12) of rotation or of movement, have a comminuting, cutting and heating effect on the plastics material, where the implements and/or blades (14) are preferably arranged or formed on or at a rotatable implement carrier (13) which is in particular a carrier disc (13) and which is in particular arranged parallel to the basal surface (12) and/or that the manner of formation, set-up, curvature and/or arrangement of the frontal regions or frontal edges (22) that are associated with the mixing and/or comminution implements (3) or with the blades (14), act on the plastics material and point in the direction (12) of rotation or of movement, differs when comparison is made with the regions that, in the direction (12) of rotation or of movement, are at the rear or behind.
15. Apparatus according to any of Claims 1 to 14, characterized in that the container (1) is substantially cylindrical with circular cross section and with a level basal surface (2) and with, orientated vertically in relation thereto, a side wall (9) which has the shape of the jacket of a cylinder, and/or the axis (10) of rotation of the mixing and/or comminution implements (3) coincides with the central axis of the container (1), and/or the axis (12) of rotation or the central axis are orientated vertically and/or normally in relation to the basal surface (2) and/or that the lowest implement carrier (13) or the lowest of the mixing and/or comminution implements (3) and/or the aperture (8) are arranged close to the base at a small distance from the basal surface (2), in particular in the region of the lowest quarter of the height of the container (1), preferably at a distance of from 10 mm to 400 mm from the basal surface (2).
16. Apparatus according to any of Claims 1 to 15, characterized in that the conveyor (5) is a single-screw extruder (6) with a single compression screw (6), or is a twin- or multiscrew extruder, where the diameters d of the individual screws (6) are all identical.