Agglomerator arrangement with connection to an extruder

Abstract

The invention relates to an arrangement (1) for processing plastics (9) having: an agglomerator (2) which is intended to process and combine plastics (9) into agglomerates; a housing; an annular die wall (5) which has a plurality of outlet openings (6) running radially outwards; a rotationally driven pressing blade (8) in the housing and within the die wall (5), which is intended to mechanically act on plastics (9) conducted into the housing and to press same radially outwards against the die wall (5) and through the outlet openings (6) thereof; and an extruder which is downstream of the agglomerator (2) and is intended to process the agglomerated plastics (9). According to the invention, the housing of the agglomerator (2) connects directly to the extruder such that the agglomerated plastics (9) are conducted from at least one opening that creates a housing outlet (18) into a conveyor screw (3), which transports the plastics (9) and is designed as an extruder screw or a feed screw of the extruder, while avoiding an intermediate processing step.

Description

[0001] "Agglomerator arrangement connected to an extruder"

[0002] Description:

[0003] The invention relates to an arrangement according to the preamble of claim 1.

[0004] DE 26 14 730 C2 discloses a generic device for processing plastic waste in the form of thermoplastic films, whereby the initially produced agglomerates are crushed into granules. It is also known in practice to crush agglomerated plastics originating from an agglomerator into granules and then further process these granules in an extruder.

[0005] The invention is based on the object of improving a generic arrangement so that it can be operated with the lowest possible energy consumption.

[0006] This object is achieved by an arrangement according to claim 1. Advantageous embodiments are described in the subclaims.

[0007] In other words, the invention proposes feeding the agglomerated plastics produced in the agglomerator as directly as possible into the extruder downstream of the agglomerator. Suitable plastics include virgin plastics or plastic waste. The plastics may contain additives such as fillers and reinforcing materials, color pigments, fibers, and the like, and they may be in the form of film pieces or fragments. While generic arrangements provide for pneumatically conveying the crushed agglomerates as granules to downstream processing units, the proposed agglomerator housing is connected to a screw conveyor.The conveyor screw can either be an extruder screw itself or a feed screw, as is provided, for example, when the extruder cannot be directly connected to the agglomerator via its extruder screw due to spatial constraints. Such feed screws are typically short and significantly shorter than the commonly used pneumatic pipe connections between two processing units.

[0008] The invention is based on the idea that in the agglomerator, the plastics are heated by mechanical traction, such as kneading and pressing, both externally, namely by the kneading or pressing tools, such as the rotating press blade, and internally due to friction during deformation. This causes the plastics to plasticize without, however, reaching their melting point. When the agglomerated plastics emerge from the annular die wall, they are at a temperature that facilitates further processing because they are already plasticized.The direct connection of the agglomerator to the extruder eliminates the energy consumption associated with pneumatic conveying, and eliminates the need to reheat the plastics for processing in the extruder. This makes the proposed arrangement energy-efficient in two ways. Furthermore, it enables a particularly compact design with minimal space requirements.

[0009] In a first embodiment of the arrangement, the housing of the agglomerator, which is directly connected to the extruder, can have the annular die wall as a housing part. In this case, the die wall is not provided with outlet openings for the agglomerated plastics evenly all around; rather, the outlet openings are only located where the housing connects to the conveyor screw, so that the agglomerated plastics pass directly from the die wall into the conveyor screw. In this embodiment of the arrangement, the housing is therefore referred to as the working housing, which has working walls, because the working housing and the working walls define the working space in which the plastics are treated by the rotating press blade, e.g., kneaded and pressed radially outwards, and in which working space the plastics, which are in the form of, for example, fingernail-sized pieces of film, are pressed into the agglomerates.

[0010] In a second embodiment of the invention, it is not the working housing itself that is directly connected to the extruder, but rather an outer housing that surrounds the working housing on the outside.

[0011] In a variant of this second design, the outer housing extends at a comparatively small distance around the die wall, creating a comparatively small collection chamber between the outer housing and the die wall, in which the agglomerated plastics emerging from the die wall are collected. The pressure under which the agglomerated plastics emerge from the die wall with the aid of the press vane displaces the agglomerated plastics already in the collection chamber, creating a flow toward the housing opening. In this way, the agglomerated plastics in the collection chamber are conveyed to the housing opening and thus into the immediately adjacent conveyor screw.

[0012] In this variant, which does not require any specially provided, movable conveyor elements within the outer casing, the collecting chamber can be designed to be heated, thus preventing the agglomerated plastics located in the collecting chamber from cooling down, which would increase flow resistance. The fact that the collecting chamber is heatable means that the agglomerated plastics located in the collecting chamber can be subjected to heat and thus kept flowable. This can be achieved, for example, by electrical resistance heating, or by a heat transfer medium flowing in a heating line or the like. For example, it can be provided to heat the components adjacent to the collecting chamber, such as the outer casing and / or the die wall, and in this way transfer the heat to the collecting chamber and the agglomerated plastics located therein.

[0013] In a second variant of the second configuration of the arrangement, which features an outer housing, the outer housing extends at a greater distance around the die wall, creating a larger collection space for the agglomerated plastics. This larger collection space offers the possibility of arranging a conveyor element in the collection space, which rotates around the die wall and, for example, has one or more carriers, so that the agglomerated plastics emerging from the die wall are conveyed to the housing opening by means of the conveyor element.

[0014] In the second variant of the second embodiment of the arrangement, which has an outer housing, the larger collecting space for the agglomerated plastics can also be used to arrange a ring shredder in the collecting space, which rotates around the die wall and whose shredding tool is designed, for example, as a knife, scraper or the like, so that the agglomerated plastics, which each emerge from an outlet opening of the die wall as a continuous strand, are shredded by means of the ring shredder into smaller separate bodies in the form of granules.

[0015] The two above-mentioned possibilities of arranging a conveyor element or a ring shredder in the collecting space can also be implemented in combination, for example by the shredding tool of the ring shredder also serving as a carrier for the produced granulate, or by a movable element being equipped with both a shredding tool and additionally with a carrier, so that this movable element forms both the ring shredder and the conveyor element.

[0016] The invention is explained in more detail below using purely schematic representations.

[0017] Fig. 1 to 3 show three different embodiments of an arrangement according to the invention, each in the form of a vertical section through the respective arrangement.

[0018] Figures 1 and 2 relate to embodiments in which an outer housing is connected to a conveyor screw and a collecting space is created between the working space, in particular the annular die wall, and the outer housing.

[0019] Fig. 1 shows an arrangement 1 comprising, on the one hand, an agglomerator 2 and, on the other hand, a conveyor screw 3. The conveyor screw 3 can be an extruder screw, i.e., a component of an extruder, or it can be a feed screw connected to the extruder. In the embodiment shown in Fig. 1, the conveying direction of the conveyor screw 3 runs from right to left.

[0020] The agglomerator 2 has a working chamber which is delimited by two spaced-apart lateral working walls 4 and by an annular die wall 5 which is provided with a plurality of outlet openings 6 which lead radially outwards from the working chamber through the die wall 5. Within the working chamber, the working walls

[0021] 4 surface profiles in the form of kneading strips 7 are provided, and furthermore a rotary-driven pressing wing 8 is arranged in the working space, which rotates counterclockwise.

[0022] Schematically indicated, small-piece plastics 9, e.g., in the form of approximately fingernail-sized pieces of film, are mechanically treated, kneaded, and pressed within the working chamber by the movement of the press wing 8, causing them to agglomerate. By means of the press wing 8, which carries pressure pieces 19 for this purpose, the agglomerated plastics 9 are pressed out of the working chamber through the outlet openings 6. They enter a collecting chamber 10, which is located outside the die wall 5 and is delimited by an outer housing 11.

[0023] Within the collecting chamber 10, a ring shredder runs in a circular manner, comprising two shredding tools 12, which, like knives, cut the agglomerated plastics 9, which each emerge as a strand of material from the outlet openings 6, into smaller particles referred to as granules. The shredding tools 12 are designed in such a way that, in their radially outer region, they are separated from the die wall

[0024] 5, form drivers 14 which convey the granulate from the collection chamber 10 into the conveyor screw 3. The ring shredder thus also represents a conveyor element. The conveyor screw 3 has a screw 15 which runs within a conveyor pipe 16. The conveyor pipe 16 has an inlet window 17 on its upper circumference which communicates with a housing outlet 18 of the outer housing 11, so that the agglomerated plastics 9 pass from the collection chamber 10 through the housing outlet 18 and the inlet window 17 into the conveyor screw 3. The drivers 14 ensure that the granulate is practically spatula-shaped into the screw 15, so that the screw 15 has as few air inclusions as possible in the plastic material.

[0025] The housing outlet 18 and / or the inlet window 17 can be closed by means of a slide valve, so that when the agglomerator 2 is started up, the granulate located in the collecting chamber 10 is initially held in the collecting chamber 10 and moved by the rotating ring crusher. Plastic granulate that is not sufficiently agglomerated, as cannot be ruled out when the agglomerator 2 is started up, can thus be held in the agglomerator 2 and further processed until it is sufficiently agglomerated, and only then is the aforementioned slide valve opened, so that start-up losses can be significantly minimized or even completely avoided.

[0026] Fig. 2 shows an embodiment of an assembly 1 which, in many respects, corresponds to the embodiment of Fig. 1, so that only the differences will be discussed below. The collecting chamber 10 is considerably smaller, since the distance between the outer housing 11 and the die wall 5 is considerably smaller than in Fig. 1.

[0027] The outer housing 11 is surrounded by a heating jacket 20 so that the outer housing 11, the collecting chamber 10, and in particular the agglomerated plastics located in the collecting chamber 10 can be protected from temperature losses or even heated. In this way, the plastics 9 located in the collecting chamber 10 are kept in a flowable state. Without the need for specially provided comminution or conveying means, a material flow of the agglomerated plastics emerging from the outlet openings 6 of the die wall 5 and entering the collecting chamber 10 is caused by the pressure of further, incoming agglomerated plastics 9. This agglomerate flow flows within the collecting chamber 10 to the housing outlet 18, where it enters the inlet window 17 of the conveyor screw 3.

[0028] Fig. 3 shows an embodiment of an arrangement 1, in which several features again correspond to those of the two embodiments described above, so that these will not be explained in more detail. In contrast to the embodiments in Figs. 1 and 2, no outer housing is provided and, correspondingly, no collection chamber outside the die wall 5. Rather, the working chamber connects to the conveyor screw 3, namely by means of the die wall 5, so that the outlet openings 6 of the die wall 5 form the housing outlet 18 and the die wall 5 together with the side walls 4 form the housing of the agglomerator 2, which connects to the conveyor screw 3.

[0029] The outlet openings 6 in the die wall 5 are therefore limited to the area in which the die wall 5 communicates with the inlet window 17 of the conveyor screw 3. In the remaining circumferential area of ​​the die wall 5, it is designed free of outlet openings 6 and, instead, is provided with a profiling 21 on the inside, towards the working chamber, in order to enable particularly intensive friction of the plastics 9 for the benefit of higher agglomeration performance.

[0030] The slide valve already mentioned above, which is not shown in Figs. 1 and 2 and serves to close the housing of the agglomerator 2 when the agglomerator 2 is started up, is shown in the embodiment of Fig. 3 and is marked with 22.

[0031] Purely by way of example, a collar 23 is shown in Fig. 3, which provides a tight connection of the housing outlet 18 of the agglomerator

[0032] 2 to the inlet window 17 of the conveyor screw 3. With appropriate wall thicknesses of the conveyor pipe 16 and / or the die wall 5, the die wall 5, as the housing of the agglomerator 2, can connect directly, without a collar 23, to the conveyor pipe 16, without a collision occurring between the die wall 5 and the screw 15.

[0033] Reference symbol:

[0034] 1 arrangement

[0035] 2 Agglomerator

[0036] 3 screw conveyor

[0037] 4 work wall

[0038] 5 matrix wall

[0039] 6 Outlet opening

[0040] 7 Kneading bar

[0041] 8 press wings

[0042] 9 Plastics

[0043] 10 Assembly room

[0044] 11 Outer casing

[0045] 12 shredding tools

[0046] 14 drivers

[0047] 15 snail

[0048] 16 conveyor pipe

[0049] 17 inlet windows

[0050] 18 Housing outlet

[0051] 19 Pressure piece

[0052] 20 heating jacket

[0053] 21 Profiling

[0054] 22 sliders

[0055] 23 collars

Claims

Claims:

1. Arrangement (1) for processing plastics (9), comprising an agglomerator (2) designed to combine plastics (9) into agglomerates, • with a housing, • and with an annular matrix wall (5) which has several radially outward extending outlet openings (6), • and with a press vane (8) driven circumferentially in the housing and within the die wall (5), which is designed to mechanically actuate plastics (9) that have entered the housing and to press them radially outwards against the die wall (5) and through its outlet openings (6), and with an extruder downstream of the agglomerator (2), which is designed to process the agglomerated plastics (9), characterized in that the housing of the agglomerator (2) connects directly to the extruder in such a way that the agglomerated plastics (9) pass from at least one opening creating a housing outlet (18) into a conveying screw (3) transporting the plastics (9), which is designed as an extruder screw or as a feed screw of the extruder, without the need for an intermediate processing step.

2. Arrangement according to claim 1, characterized in that the housing is designed as a substantially cylindrical working housing which has two lateral working walls (4) and the annular die wall (5) which connects the two lateral working walls (4), wherein the die wall (5) connects to the screw conveyor (3) and the outlet openings (6) are limited to the area of ​​the die wall (5) in which the die wall (5) connects to the screw conveyor (3), such that the outlet openings (6) of the die wall (5) form the housing outlet (18) through which the agglomerated plastics (9) enter the screw conveyor (3). Arrangement according to claim 1, characterized in that the housing is designed as an outer housing (11) which surrounds the annular die wall (5) at a distance and forms the housing outlet (18) through which the agglomerated plastics (9) enter the screw conveyor (3), wherein the outer housing (11) creates a collection space (10) between the die wall (5) and the outer housing (11) for the agglomerated plastics (9) that have come out of the outlet openings (6) of the die wall (5).Arrangement according to claim 3, characterized in that the collection chamber (10) is heatable and the outer housing (11) extends at such a small distance around the die wall (5) that the agglomerated plastics (9) located in the collection chamber (10) are conveyed to the housing outlet (18) by inflowing plastics (9) emerging from the outlet openings (6) of the die wall (5). Arrangement according to claim 3, characterized in that a conveying element is arranged in the collection chamber (10) which is driven around the die wall (5) and is designed to convey the plastics (9) emerging from the outlet openings (6) of the die wall (5) into the collection chamber (10). to convey the agglomerated plastics (9) to the housing outlet (18). Arrangement according to claim 3, characterized in that a ring crusher is arranged in the collection chamber (10), which is driven around the die wall (5) and is designed to crush the agglomerated plastics (9) entering the collection chamber (10) from the outlet openings (6) of the die wall (5) into granules.

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