Disc agglomerator with a starting aid

Abstract

The invention relates to a disc agglomerator which is designed to receive plastic waste and form same into elongated pin-shaped or sausage-shaped agglomerates in a pasty state, comprising two discs which are profiled on the mutually facing surfaces thereof, can be moved relative to each other, and are arranged parallel and at a distance to each other and between which a disc intermediate area is formed. The agglomerator has an inlet opening for the recycled plastic, said opening leading into the central region of the disc intermediate area, and an outlet opening for the agglomerates in the outer circumference of the disc intermediate area. According to the invention, the outlet opening (34) can be selectively at least partly closed by means of a closure such that the outlet opening is restricted such that the agglomerates cannot pass through at all or can pass only to a limited extent.

Description

[0001] "Disc agglomerator with starting aid"

[0002] Description:

[0003] The invention relates to a disc agglomerator according to the preamble of claim 1.

[0004] EP 2 817 131 B1 discloses a generic disc agglomerator in which plastic waste is processed into elongated strands of material. These strands can then be shredded to form small particles. For the purposes of this proposal, both the plastic waste to be recycled in the disc agglomerator and the agglomerates produced in the disc agglomerator are referred to as plastic recyclate.

[0005] These particles can later be used as raw materials in the plastics processing industry, for example, they can be further processed in an extruder.

[0006] The invention is based on the object of improving a generic disc agglomerator in such a way that it can be operated with low energy and economic expenditure.

[0007] This object is achieved by a disc agglomerator according to claim 1. Advantageous embodiments are described in the subclaims. In other words, the invention proposes retaining the agglomerated material strands, which strive radially outward between the two discs of the disc agglomerator and towards the outlet opening of the disc agglomerator, in the disc agglomerator when the disc agglomerator is put into operation for the first time or after a rest period - i.e., when it is "started up". For this purpose, an outlet opening of the disc agglomerator is partially or completely closed so that the material located between the discs that is not yet sufficiently agglomerated remains between the discs. Only gradually, as the operating time of the disc agglomerator increases, is the outlet opening enlarged.Accordingly, the possibility of closing the outlet opening when starting up the disc agglomerator is referred to as a start-up aid.

[0008] The invention is based on the idea that when the ring agglomerator is started up, there is initially only a small amount of recycled plastic between the two discs. Depending on the material used, it may happen that instead of the desired elongated material strands, for example, imperfect, flake-like agglomerates are initially formed, which complicates further processing in the systems downstream of the agglomerator. By reducing the size of the outlet opening or even completely closing it, the residence time of the material in the disc agglomerator can be extended until the material is sufficiently agglomerated and, for example, the desired elongated material strands are formed.

[0009] The two discs of the disc agglomerator are movable relative to each other. For example, both can be rotationally driven at different speeds and / or in different directions of rotation. Or one disc, known as the stator, is stationary and the other, known as the rotor, is rotationally driven. The plastic material to be processed that enters the space between the discs is heated and agglomerated due to external kneading action, namely by a surface profiling of the discs, e.g. in the form of elongated kneading bars, as well as due to the internal friction generated, so that it can later be further processed in another system. The start-up aid provided according to the invention is, on the one hand, energetically advantageous compared to collecting the insufficiently agglomerated material and later feeding it back into the disc agglomerator during ongoing operation, where it is mechanically processed and heated again.

[0010] Due to the energy advantage, there is also an economic advantage in avoiding the need to feed material into the disc agglomerator and heat it twice, or even having to discard the insufficiently agglomerated material that is produced during start-up.

[0011] In a disc agglomerator, the outlet opening is either the gap opening resulting from the distance between the two discs, i.e. an annular opening between the two discs on their outer circumference, corresponding to the disc circumference, or an opening in a housing surrounding the two discs.

[0012] In one embodiment, the outlet opening of the disc agglomerator can be located directly on the periphery of the two discs. The space between the discs, in which the material is located between the discs, creates an annular, circumferential gap on the outer periphery of the discs, which accordingly creates an annular, circumferential outlet opening through which the agglomerates can emerge radially outward from the space between the discs.

[0013] As a variant of this design, the outlet opening can be selectively closed or opened, either completely or partially, depending on the position of the ring, by means of a ring that is movable in the axial direction and can be moved or retracted across the gap. Due to the annular design of the closure element, with which the outlet opening can be selectively closed or opened, and because this ring forms the starting aid, the ring can be referred to as a starting ring.

[0014] As another variant of this design, the circumferential gap can be practically closed by a housing that fits tightly to the circumference of the two discs, but at least without contact with the rotating disc, if an outlet opening of the housing is closed and a material backflow immediately forms on the circumference of the two discs, so that no material can escape from the space between the discs.

[0015] In another embodiment, the outlet opening of the disc agglomerator can be located at a distance from the periphery of the two discs, for example, if the housing does not fit as tightly as possible to the periphery of the two discs, but rather if the housing extends at a distance around the two discs and has a closable outlet opening. In this case, too, the material backlog described above occurs between the discs, albeit with a delay. This is because the space inside the housing and outside the discs is first filled with material.

[0016] In order to process and agglomerate even the insufficiently agglomerated material that collects in this space, drivers, scrapers, or similar elements can be provided in this space. The drivers, scrapers, or similar elements can be arranged on a rotating disc so that they rotate together with the disc and move through the aforementioned space. Due to this movement, the material collected in this space is mechanically acted upon, and this material is further agglomerated. With the outlet opening open, during operation of the disc agglomerator after start-up, there is practically no relative movement between the drivers, scrapers, or similar elements and the material in the space; rather, they can then serve to convey the agglomerated material that has emerged between the discs in the space to the outlet opening.

[0017] In one embodiment, the agglomerated material strands can be shredded using a ring shredder, i.e., with several shredding tools arranged in a circular line and located radially adjacent to or outside the outlet opening, and thus downstream of the disc agglomerator in the flow direction of the recycled plastic. The agglomerated material strands emerging from the outlet opening of the disc agglomerator are accordingly brought into contact with the shredding tools and broken down into shorter pieces, namely the small particles mentioned above, which can be used as starting material in a downstream plant in the plastics processing industry.

[0018] The comminution eliminates the need to transport the material strands via an additional conveyor system to a comminution device located at a distance from the disc agglomerator, further enhancing the energy efficiency of the disc agglomerator. Not only can the energy required for this additional conveyor system be saved, but the cooling process that would otherwise occur when transporting the material strands to a comminution device is also avoided. Instead, the relatively softer, not yet cooled, material strands are comminuted directly at the exit of the disc agglomerator, so the energy required for this comminution is lower than the energy required to comminution the same, but cooled and thus harder, material strands.Ultimately, this will create a particularly compact agglomeration and crushing plant.

[0019] The comminution tools can, for example, be arranged directly on a disc of the disc agglomerator, or they can be mounted on a dedicated ring, which is therefore referred to as a comminution ring. For example, the aforementioned start-up ring can form a component of the ring crusher by supporting the comminution tools, so that the start-up ring simultaneously also forms the comminution ring.

[0020] The start-up or shredding ring can be adjusted in the axial direction of the ring agglomerator, i.e. essentially transversely to the plane of the two discs, so that it opens or closes the annular outlet opening to varying degrees in the axial direction, i.e. can make the gap width of the outlet opening narrower or wider. Adjusting the gap width of the outlet opening is likely to be of minor importance during continuous operation of the ring agglomerator. However, in addition to the start-up aid, it also offers the possibility of adapting the gap width to different plastic recyclates to be processed, so that in different facilities where different types or compositions of plastic waste are processed, the shredding can be easily adjusted to the optimal gap width of the outlet opening.

[0021] The outlet opening can be enlarged based on in-house experience, for example, after a certain period of time. Alternatively, the outlet opening can be enlarged automatically by moving the start-up ring, for example, motor-driven, depending on the current consumption if the disc agglomerator is driven by an electric motor and the current consumption reaches a certain value due to the increased rotational resistance that occurs between the discs. This can be an absolute value, i.e., a specific current of X amperes.

[0022] However, the specific value can also be a relative value, resulting, for example, from the temporal progression of the power consumption. For example, the power consumption can rise with increasing fill level if increasing amounts of plastic recyclate enter the space between the two discs. If less material exits the outlet opening per unit of time than plastic recyclate flows into the space because the outlet opening is partially or completely closed, this leads to an increase in the amount of plastic recyclate in the space. Due to the higher fill level and the longer residence time, the material is processed more intensively in the disc agglomerator and takes on higher temperatures due to external influences and internal friction.

[0023] The resulting softening of the material leads to a reduction in the rotational resistance of the disc agglomerator, so that the power consumption of the drive motor at least does not increase further and typically even decreases again. If the power consumption is monitored by an electronic system control system, the outlet opening can be automatically enlarged based on the current consumption curve. This is achieved by automatically controlling the drive means of the comminution ring and automatically moving the comminution ring in the axial direction. The agglomerated material in the disc agglomerator can now leave the disc agglomerator through the outlet opening in the form of the desired material strands, which are then divided into the desired shorter pieces in the comminution ring.The possibility of completely or partially closing the outlet opening of the disc agglomerator during the start-up phase can be achieved, depending on the design of the disc agglomerator and its outlet opening, by an axial adjustment of the two discs relative to each other, by an adjustable start-up ring - with or without crushing tools - or by a movable slide or similar closure elements closing the outlet opening.

[0024] In a conventional manner, the disc agglomerator can be designed such that not both discs rotate, but rather one disc remains stationary. This disc, known as the stator, has the inlet opening through which the recycled plastic enters the space between the two discs. The other disc, known as the rotor, is rotatably mounted and driven. In this design, the shredding ring—which can also serve as the starting ring—can be mounted on the stator in a rotationally fixed manner.Initial practical tests have shown that an excellent comminution effect can be achieved even when the comminution ring is stationary, since the agglomerated material strands are carried along by the rotor and move relative to the stator and accordingly also to the comminution ring not only in the radial but also in the tangential direction, so that the comminution tools can act on the material strands.

[0025] In principle, the comminution tools can simply form an abutment against which the material strands emerging from the disc agglomerator collide, shearing them off and thus comminuting them. In one embodiment, the comminution tools can be designed as knives, so that the comminution of the material strands can take place with as little resistance as possible and therefore requires as little energy as possible. The knives can advantageously be arranged at an angle of between 35° and 80° with respect to the axis of the agglomerator, as far as the cutting edge of the knives is concerned. This creates a pulling cut, which is advantageous in terms of energy and also reduces the mechanical stress on the knives.With regard to these two aspects, the angle at which the cutting edges of the knives are aligned to the axis of the agglomerator can, in a configuration considered advantageous, be between 45° and 60°.

[0026] In one embodiment, the blades can be arranged in the ring shredder so that they can be replaced. This allows for quick and easy replacement of individual worn blades, or, if necessary, the replacement of one or all of the blades with differently shaped cutting edges.

[0027] In one embodiment, the knives can each be arranged in a knife holder that is replaceably mounted on the ring shredder. This also allows for the replacement of individual or all of the knives, as explained above. Furthermore, the knife holder can be designed as a stable element, eliminating the need to handle a narrow, delicate knife separately. For example, the knife holder, which can be made of a greater material thickness than the knife itself, allows the knife to be screwed to the ring shredder with a high tightening torque of the fastening screw without endangering the knife.

[0028] Regardless of whether the knives are attached to the ring shredder directly or by means of a knife holder, they can be mounted in one design so that they can be adjusted in the radial direction. In this way, the gap width of the annular gap that results between the outlet opening and the knives can be adjusted in order to influence the size of the shorter pieces produced. In one design, the shredding ring can have several receptacles designed to accommodate shredding tools, for example by holding the knives themselves or the knife holders equipped with the knives in the receptacles. In this design, the shredding ring can have so many receptacles that in many practical applications a corresponding number of knives is not necessary.Accordingly, in this system configuration, not all receptacles are equipped with a shredding tool. Depending on the plastic recyclate used or the desired size of the shorter pieces into which the agglomerated material strands are to be shredded, the number of shredding tools used can vary.

[0029] In this design, the receptacles that are not required and therefore not equipped with a shredding tool are covered with a cover element. This protects the receptacles themselves, for example, from contamination that could potentially complicate the subsequent installation of a shredding tool in this receptacle. Furthermore, personnel protection is achieved in terms of accident prevention by ensuring the system has the smoothest possible surface and avoiding a jagged outer surface of the shredding ring.

[0030] In one embodiment, it can be provided that the ring shredder not only has a row of shredding tools arranged in a ring on the stator of the disc agglomerator, but rather has a row of shredding tools arranged in a ring on each of the discs, so that the agglomerated material strands emerging radially outward from the outlet opening are shredded into short pieces by a shearing movement between the two different rows of shredding tools. The system therefore has first shredding tools arranged on a first circular line with a first diameter and connected to a first disc of the disc agglomerator, and second shredding tools arranged on a second circular line with a second diameter and connected to a second disc of the disc agglomerator.The first and second comminution tools are movable relative to each other, as the two discs of the disc agglomerator are movable relative to each other. The diameters of the first and second circular lines differ, so that the first and second comminution tools interact like scissors, shredding the agglomerated material strands between them.

[0031] In this described embodiment of the system, it can be provided that the first and second comminution tools are each arranged on a retaining ring that is connected to the respective first and second disc of the disc agglomerator. Both retaining rings each have a free space designed as an annular groove, into which the comminution tools arranged on the other retaining ring can be inserted when the comminution tools are adjusted in the axial direction of the disc agglomerator. For example, if the comminution tools arranged on the stator are adjusted in the axial direction toward the rotor, the comminution tools each insert into the annular groove of the opposite retaining ring.Due to the possibility of being accommodated in the respective opposing retaining ring, the comminution tools can be designed so long that a shearing effect between the comminution tools can be ensured across the entire gap width, even with a large gap width of the outlet opening. The invention is explained in more detail below using purely schematic representations, whereby individual design features of a specific embodiment of a system for agglomerating and comminuting plastic recyclate are not limited to this embodiment, but can also be implemented in other configurations and / or in other combinations.

[0032] Fig. 1 is a perspective view of a plant for agglomerating and shredding plastic recyclate, with a first disc agglomerator,

[0033] Fig. 2 and 3 views of a first embodiment of a ring crusher, in a normal position

[0034] Fig. 4 and 5 views of the ring crusher of Fig. 2 and 3, in a starting position,

[0035] Fig. 6 is a perspective view of a crushing ring of the ring crusher of Figs. 2 to 5,

[0036] Fig. 7 is a vertical cross-section through a second embodiment of a disc agglomerator,

[0037] Fig. 8 is a perspective view of a longitudinal section through a second ring crusher in the starting position,

[0038] Fig. 9 is a view of the ring crusher of Fig. 8 in the normal position,

[0039] Fig. 10 is a perspective view of a longitudinal section through a third ring crusher in the starting position,

[0040] Fig. 11 is a view of the ring crusher of Fig. 10 in the normal position,

[0041] Fig. 12 a vertical cross section through another embodiment of a disc agglomerator,

[0042] Fig. 13 is a vertical longitudinal section through the upper portion of the disc agglomerator of Fig. 12 in the start-up position, and Fig. 14 is a vertical longitudinal section through the lower portion of the disc agglomerator of Fig. 12 in the start-up position, and

[0043] Fig. 15 shows a vertical cross-section similar to Fig. 12 through a fourth disc agglomerator.

[0044] Fig. 1 shows a plant 1 for agglomerating and shredding plastic recyclate, which has a disc agglomerator 2. Fig. 1 shows the viewer the rear side of a first disc, referred to as stator 3, of the disc agglomerator 2, with a central inlet opening 4 through which the plastic recyclate is introduced into a space between the two discs. Through the inlet opening 4, the view falls on a rotationally driven second disc, referred to as rotor 5, of the disc agglomerator 2. By means of three stator actuating cylinders 6s, the stator 3 can be moved in the axial direction so that the gap width between the stator 3 and the rotor 5 can be changed. By means of three ring actuating cylinders 6r, each of which has an essentially cylindrical protective cover, a shredding ring can be moved in the axial direction, as will be explained in more detail later.

[0045] In the lower peripheral area of ​​the two discs of the disc agglomerator 2, a conveyor device 7 is connected to the disc agglomerator 2, so that the agglomerates produced in the disc agglomerator 2 can be transported by means of the conveyor device 7 in a conveying direction F to a downstream device. An exhaust connection 7a serves to remove gases produced during agglomeration from the agglomerate stream, so that unwanted gas entry, for example into a downstream extruder, can be reduced as much as possible.

[0046] Figures 2 and 3 each show the central components of a

[0047] Disc agglomerator 2, namely the rotor 5, which can be connected to a drive shaft, and the stator 3, which is largely concealed by a ring shredder 8. The ring shredder 8 consists of a shredding ring 9 and several shredding tools 10, whereby the shredding ring 9 in turn is composed of three segments 11. In Figs. 2 and 3, the disc agglomerator 2 is in its normal position, which it normally assumes during operation, namely with a certain distance between the stator 3 and the rotor 5, so that on the outer circumference of the disc agglomerator 2, a circumferential gap 12 is created between the two discs. In this normal position, the gap 12 forms an open, annular outlet opening 34 on its outer circumference between the two discs of the disc agglomerator 2.

[0048] The three ring actuating cylinders 6r allow the comminution ring 9, which is arranged radially outward on the lateral surface of the stator 3, to be moved in the axial direction and thus brought closer to or further away from the rotor 5, even if the stator 3 maintains its position. This allows the comminution ring 9 to be brought into the working position shown in Figs. 2 and 3, namely into a retracted position away from the rotor 5, in which the outlet opening 34 is open, so that the comminution tools 10 of the ring comminutor 8 are arranged radially outside the circumferential gap 12 and the outlet opening 34. The elongated agglomerates emerging from the outlet opening 34 between the stator 3 and the rotor 5 at the circumference of the gap 12 are captured by the comminution tools 10 and, assisted by the rotational movement of the rotor 5 and the inclined position of the comminution tools 10 shown in Figs. 2 and 3, are crushed in a pulling cut.

[0049] When the ring actuating cylinders 6r are extended, the crushing ring 9 of the ring crusher 8 is pushed over the gap 12, thus closing the outlet opening 34. This is referred to as the starting position of the disc agglomerator 2 and ensures that the material located between the stator 3 and the rotor 5 in the disc agglomerator 2 cannot escape radially outward from the outlet opening 34 as quickly when the disc agglomerator 2 starts up, but can be held in the disc agglomerator 2 for a longer time and mechanically processed. The crushing ring 9 thus forms the starting aid.Although direct contact between the stationary and rotating components of the disc agglomerator 2 is avoided, the minimal opening width of the outlet opening 34 and the required directional deflection that the material must take on its path radially outwards create a type of labyrinth seal with the comminution ring 9 moved into the start-up position, which seals the outlet opening 34 sufficiently tightly from a practical point of view.

[0050] The start-up process is shortened by closing the outlet opening 34, and the escape of insufficiently agglomerated material can be largely or even completely prevented. Therefore, in deviation from the illustrated embodiment, the comminution ring 9 can also be used without comminution tools 10, so that in this case it can be referred to as a start-up ring, which merely has the closing function of closing the outlet opening 34 when the disc agglomerator 2 starts up.

[0051] Figures 4 and 5 show the central components of the disc agglomerator 2 of Figures 2 and 3, but in a so-called starting position, in which the two discs are spaced closer together, so that there is practically no gap 12 between the stator 3 and the rotor 5. In particular, it can be seen from Figure 4 that the rotor 5 is provided with a number of deflectors 14, which serve to convey plastic recyclate, which has reached behind the rotor 5 in an agglomerated or non-agglomerated state, radially outwards and to prevent it from reaching the drive shaft of the disc agglomerator 2.

[0052] Fig. 6 shows the ring shredder 8 separate from the other components of the disc agglomerator 2. The structure of the shredding ring 9, consisting of three segments 11, is visible. The shredding tools 10 each have a holder 15 and an interchangeable blade 16 arranged therein. The cutting edges of the blades 16 are each aligned at an angle of approximately 45° to the axis of the disc agglomerator 2, so that a pulling cut is achieved when, due to the rotational movement of the rotor 5, the agglomerates emerging from the gap 12 are guided in the direction of rotation against the blades 16. Because the agglomerates are carried along by the rotor 5 in the direction of rotation, the rotor 5 also provides the cutting energy required for cutting.

[0053] The holders 15 are fixed to the segments 11 by means of elongated holes in the radial direction so that the radial distance at which the knives 16 are located in front of the gap 12 can be adjusted. Each segment 11 has three so-called receptacles 17, namely mounting locations for comminution tools 10, and thus offers the possibility of mounting three comminution tools 10 on a segment 11. In the illustrated embodiment, only one comminution tool 10 is shown per segment 11, while the two remaining receptacles 17 are each protected against contamination and the ingress of plastic by means of a cover element 18 in order to enable problem-free mounting of a comminution tool 10 if necessary.

[0054] Fig. 7 shows a vertical section through the gap 12 of a disc agglomerator 2, so that the stator 3 is not visible, but rather the rotor 5 and its central opening for receiving a drive shaft are visible. On the surface of the rotor 5, a multitude of differently designed kneading bars 19 can be seen. These serve to mechanically treat, heat, and agglomerate the plastic recyclate entering the disc agglomerator 2 in cooperation with the stator 3, which also has a profiled surface, forming elongated agglomerates. The plastic recyclate migrates radially outward from the central inlet opening 4 and leaves the space between the two discs through the gap 12. In the embodiment of Fig. 7, the outlet opening 34 is also created on the outer circumference of the two discs, as a circumferential opening of the gap 12 between the stator 3 and the rotor 5.

[0055] 7 and 8, the agglomerates enter a ring shredder 8 which has shredding tools 10 which, in contrast to the embodiment in Figs. 2 to 6, are not designed as knives. Rather, the ring shredder 8 in Fig. 7 has two shredding rings 9 with different effective diameters. The shredding ring 9 shown on the right in Fig. 8 is referred to as the outer shredding ring 9 because its shredding tools 10 are located on a circular line with a comparatively larger diameter, and is connected to the stator 3. In the so-called inner shredding ring 9, shown on the left in Fig. 8, the shredding tools 10 are located on a circular line with a smaller diameter than the outer shredding ring 9.The inner crushing ring 9 is connected to the rotor 5, thus achieving a relative movement between the two crushing rings 9. Since the crushing tools 10 of the two crushing rings 9 are arranged on circular lines of different radii, the inner and outer crushing tools 10 interact to produce a cutting effect and divide the elongated agglomerates through their combined shearing action. A rhomboid cross-sectional shape of the crushing tools 10 promotes this shearing action.

[0056] At a radial distance from the two discs of the disc agglomerator 2, a housing 20 extends outside the illustrated rotor 5, so that the agglomerates emerging through the gap 12 and reduced into shorter pieces in the ring crusher 8 can be pneumatically removed. For this purpose, the housing 20 is connected to a pneumatic conveying line 21, as shown in Fig. 7. Apart from the fact that a fan (not visible in the drawing) generates an air flow in the conveying line 21, the direction of rotation of the rotor 5 also generates or supports an air flow that transports the agglomerates reduced into shorter pieces through the conveying line 21 in a conveying direction F indicated by an arrow.

[0057] Fig. 8 shows a section through the upper circumferential region of the disc agglomerator 2 of Fig. 7. The stator 3 and the rotor 5 can be seen within the housing 20. Similar to the exemplary embodiment in Figs. 4 and 5, the exemplary embodiment in Fig. 8 is also in its starting position. In the exemplary embodiment in Figs. 7 and 8, the starting position is achieved by axially adjusting the stator 3 using the disc adjusting cylinders 6s, so that the gap 12 on the outer circumference of the two discs is closed by the stator 3 being adjusted axially up to the rotor 5. Accordingly, the two comminution rings 9 of the ring comminutor 8 also bear against one another. In this exemplary embodiment, the starting aid is provided by both the two discs and the two comminution rings 9.Both comminution rings 9 are each provided with a circumferential annular groove 22 on their mutually facing end faces, which serves to accommodate the comminution tools 10 of the respective opposite comminution ring 9. A disc space 23 tapers to a gap 12, and in the starting position shown, both the gap 12 and the outlet opening 34 are considered practically closed at its outer circumference, even if the stationary and rotating components of the disc agglomerator 2 do not touch, but rather have a minimal distance from each other.

[0058] Because the gap 12 is completely open as in Fig. 8 or, in contrast to the embodiment in Fig. 8, possibly slightly open, the plastic recyclate is held in the space between the discs when the disc agglomerator 2 is put into operation, i.e. when it is "started up". Losses in the form of plastic recyclate that is not sufficiently agglomerated and is therefore not suitable for further processing can be reduced or even completely avoided in this way. Only when the material that has entered the space between the discs between the stator 3 and the rotor 5 during start-up has sufficiently agglomerated is the stator 3 removed from the rotor 5 by means of the adjusting cylinders 6r and the gap 12 opened wide enough for agglomerates to escape and enter the ring shredder 8.

[0059] Fig. 9 shows the embodiment of Fig. 8 after the disc agglomerator 2 has been started up, when it assumes its normal position and, by adjusting the stator 3, the space between the discs has been enlarged and the gap 12 and the outlet opening 34 have been opened. It can be seen how the comminution tools 10, arranged at different radii, interact in a shearing manner and have emerged from the annular groove 22 of the respective opposite comminution ring 9.

[0060] Fig. 10 shows a situation similar to Fig. 8, wherein in Fig. 10, a disc space 23 between the stator 3 and rotor 5 is closed at the outer circumference by means of a disc actuating cylinder 6s, since the disc agglomerator 2 shown in Fig. 10 is in its starting position. In this embodiment, the comminution tools 10 are shown as cylindrical pins, which have a comminution-effective cutting or inclined surface outside their respective comminution ring 9.

[0061] Fig. 11 shows a situation similar to Fig. 9 for the embodiment of Fig. 10, in which the gap 12 is opened by corresponding adjustment of the stator 3 and the disc agglomerator 2 assumes its normal position.

[0062] Fig. 12 shows a view similar to Fig. 7 of another embodiment of a disc agglomerator 2 and its rotor 5, but the kneading bars 19 of the rotor 5 are configured differently than in Fig. 7. The housing 20 is also designed differently in that it runs at a comparatively shorter distance around the two discs of the disc agglomerator 2. A ring shredder 8 is designed to interact with the housing 20. The ring shredder 8 does not have a physical shredding ring 9, but rather a plurality of shredding tools 10 that are arranged on a circular line and thus form a shredding ring. In the embodiment of Fig. 12, no pneumatic conveying of the agglomerates cut into shorter pieces is provided. Rather, the elongated agglomerates emerging from the gap 12 are conveyed by means of the shredding tools 10.Unlike the deflectors 14 in Fig. 7, the comminution tools 10 in Fig. 12 are not arranged on the rear side of the rotor 5, but rather adjoin radially outwardly to the outer circumference of the rotor 5. However, similar to the deflectors 14 in Fig. 7, they also serve to clear the space within the housing 20 into which plastic material enters and to transport the captured material. By means of the comminution tools 10, the captured material is conveyed within the housing 20 to a housing opening 24, which forms the outlet opening 34 of the disc agglomerator 2. There, a shearing action for comminuting the agglomerates occurs not with the aid of a second comminution ring, but rather in interaction with the edge of the housing 20, which surrounds the housing opening 24.The elongated agglomerates are not crushed into separate, shorter pieces, but are literally spatula-shaped into the space adjacent to the housing opening 24 and thus crushed. For this purpose, the crushing tools 10 have a front side acting on the material, which deviates from a purely radial orientation to the rear at a suitable angle. In this way, a spatula-like effect is achieved, with which the material is introduced into a conveying line 21, which, in the illustrated embodiment, is directly connected to the housing 20.

[0063] In contrast to the embodiment of Fig. 7, the conveyor line 21 of Fig. 12 does not serve for the pneumatic transport of the material, but rather has a conveyor screw 25 that transports the material in the conveying direction F. To ensure good filling of the conveyor screw 25, in this embodiment the conveying direction F runs opposite to the direction in which the rotor 5 moves in the region of the housing opening 24. The conveyor line 21 can, for example, be the intake screw of an extruder or a short transfer screw, which in turn is connected to an extruder screw.In both cases, the temperature losses of the material can be kept as low as possible, so that in a particularly energetically advantageous embodiment of the system 1, the plastic material, which is initially agglomerated and then comminuted into shorter pieces, can be further processed in an extruder that is connected downstream of the disc agglomerator 2 with the shortest possible route. The conveyor line 21 has an opening where it connects to the housing 20 of the disc agglomerator 2. In contrast to the illustrated embodiment, a closure element can be arranged between the housing 20 and the conveyor line 21 as a start-up aid, for example in the form of a slide valve arranged on the housing 20 or on the conveyor line 21.Similar to the possibility of closing the outlet opening 34 by means of an axially adjustable comminution ring 9 or an axially adjustable stator 3, material can also be held in the disc agglomerator 2 during the start-up phase by means of the closure element until the material is sufficiently agglomerated.

[0064] Furthermore, not shown in the embodiment of Fig. 12, a suction connection can be arranged in the region of the transition from the housing 20 to the conveyor line 21 in order to be able to suck out gases produced during agglomeration before these gases can reach the conveyor screw 25.

[0065] In contrast to the embodiment shown in Fig. 12, the scraper-like comminution tools 10 can be omitted and the housing 20 can run radially outwards tightly around the discs of the disc agglomerator 2. The smallest possible distance between the housing 20 and the discs ensures friction-free and trouble-free operation of the disc agglomerator 2, but also prevents larger accumulations of agglomerates from radially moving outwards between the discs. The pressure that builds up in the space 23 between the discs due to the material being conveyed into the disc agglomerator 2, as well as the centrifugal forces generated by the rotor 5 in the disc agglomerator 2 and the conveying effect of the kneading bars 19 cause the agglomerates to push radially outwards. Fig. 13 shows a section through the upper region of the disc agglomerator 2 from Fig.12, which is in its starting position, so that the gap 12 and the outlet opening 34 on the outer circumference of the disc space 23 are closed. The section in Fig. 13 runs through a comminution tool 10 of the ring comminutor 8. By means of different screws 26, both the housing 20 is fastened to the stator 3 and the comminution tools 10 are fastened to the rotor 5. Behind the rotor 5, a rotor holder 27 is shown, which is provided with a sealing ring 28 on its outer circumference.

[0066] The sealing ring 28 has a thread profile 30, namely a helical groove, extending toward a space 29 that extends radially outside the gap 12 in a ring around the discs of the disc agglomerator 2, as well as on its radial outer side, toward the housing 20. The pitch of this thread profile 30 is coordinated with the direction of rotation of the rotor 5 in such a way that any material that has penetrated into the helical groove is conveyed back into the space 29.

[0067] Furthermore, sealing air is used to counteract the penetration of plastic into the area of ​​the thread profile 30: the housing 20 is provided with an air connection 31 to which a compressed air line can be connected. The compressed air flows into a circular sealing air channel 32 and from there into the area of ​​the thread profile 30, forcing any material located between the sealing ring 28 and the housing 20 back into the space 29.

[0068] Fig. 14 shows the lower circumferential area of ​​the disc agglomerator 2 of Figs. 12 and 13. The section runs in the longitudinal direction of the axis of rotation around which the rotor 5 rotates, and thus transversely to the conveyor screw 25. On the inside of the tubular housing of the conveyor line 21, the conveyor line 21 has several retaining grooves 33, each having a wedge cross-section. They serve to prevent the material, which has been introduced into the conveyor line 21 through the housing opening 24 with the aid of the comminution tools 10, from rotating together with the conveyor screw 25, so that a translatory movement of the material within the conveyor line 21 can be achieved by means of the conveyor screw 25 with the greatest possible conveying efficiency.

[0069] Fig. 15 shows, similar to the illustration in Fig. 12, the lower peripheral area of ​​another variant of a disc agglomerator 2. In this variant, no drivers are provided on the outer circumference of the rotor 5. The conveying effect with which the agglomerates are introduced into the conveying line 21 is based on the rotary movement of the rotor 5, the shape of the kneading bars 19 and the supply of material that is conveyed into the disc agglomerator 2. In order to keep the material between the stator 3 and the rotor 5 for a sufficiently long time when starting up the disc agglomerator 2 and to ensure sufficient agglomeration, the housing 20 can be closed by means of a housing slide 35 and / or the conveying line 21 can be closed by means of a line slide 36 as a start-up aid. Purely as an example, Fig.15 shows both slides as starting aids, so that, for example, depending on the plastic material being processed in the disc agglomerator 2, either the housing slide 35 or the line slide 36 can be used. Deviating from Fig. 15, the disc agglomerator 2 can have only one of the two slides. Reference numeral:

[0070] Plant disc agglomerator stator

[0071] Inlet opening rotor

[0072] 6s = Stator actuating cylinder 6r = Ring actuating cylinder Conveying device, 7a = Suction connection F = Conveying direction Ring shredder Shredding ring Shredding tool Segment Gap Deflector Holder Blade Receptacle Cover element Kneading bars Housing Conveying line Ring groove Disc space Housing opening Conveyor screw Screw Rotor receptacle Sealing ring Space

[0073] Thread profile Air connection Sealing air duct Retaining groove Outlet opening Housing slide Line slide

Claims

Claims:

1. Disc agglomerator (2), o designed to receive plastic waste and form it into elongated, cone-shaped or sausage-shaped agglomerates in a doughy state, o with two discs, ■ which are profiled on their mutually facing surfaces, ■ are movable relative to each other, ■ are arranged parallel to each other and at a distance from each other ■ and create a disc space (23) between them, o and which has an inlet opening (4) for the plastic recyclate, which opens into the central area of ​​the disc space (23), o and which has an outlet opening (34) for the agglomerates, characterized in that the outlet opening (34) can be selectively closed at least partially by means of a closure in such a way that it is only partially or not at all passable for the agglomerates.

2. Disc agglomerator according to claim 1, characterized in that the outlet opening (34) is arranged in the outer circumference of the disc space (23), and that the closure has a starting ring which is arranged radially outside the outlet opening (34) and is movable in the axial direction of the ring agglomerator (2) in such a way that it selectively opens the outlet opening (34). a disc agglomerator according to claim 2, characterized by a ring crusher (8) with several crushing tools (10) arranged annularly adjacent to the outlet opening (34), wherein the crushing tools (10) are arranged radially outside the space between the discs (23), such that agglomerates emerging from the outlet opening (34) are broken down into shorter pieces by means of the crushing tools (10), and wherein the starting ring is designed as a crushing ring (9) of the ring crusher (8) and carries the crushing tools (10). Disc agglomerator according to claim 3, characterized in that one of the two discs of the ring agglomerator (2) is arranged as a stator (3) so as to be non-rotatable and has the inlet opening (4), and the second disc is rotatably mounted as a rotor (5), wherein the crushing ring (9) is held non-rotatably on the stator (3).Disc agglomerator according to claim 1, characterized in that a housing (20) extends annularly around the discs of the disc agglomerator (2) and the outlet opening (34) of the disc agglomerator (2) is designed in the form of a housing opening (24) which connects to a conveying line (21). Disc agglomerator according to claim 5, characterized in that comminution tools (10) are arranged radially within. The discharge opening (34) extends effectively into the space (29) between the housing (20) and the discs of the disc agglomerator (2), such that it breaks down agglomerates located in this space and conveys them to the housing opening (24). Disc agglomerator according to claim 5 or 6, characterized in that a conveying line (21) with a conveying screw (25) is connected to the disc agglomerator (2). Disc agglomerator according to claim 7, characterized in that the conveying line (21) is configured as an extruder screw or as a transfer screw connected to an extruder. Disc agglomerator according to any one of claims 5 to 8, characterized in that the conveying line (21) can be selectively closed by means of a line slide (36).Disc agglomerator according to one of the preceding claims, characterized in that a housing (20) extends annularly around the outside of the discs of the disc agglomerator (2) and the outlet opening (34) of the disc agglomerator (2) is designed in the form of a housing opening (24) which can be selectively closed by means of a housing slide (35).

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