JPS6235884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an apparatus for compressing and granulating thermoplastic waste (hereinafter referred to as a compression/granulating apparatus), and more specifically, the present invention relates to an apparatus for compressing and granulating thermoplastic waste (hereinafter referred to as a compression/granulating apparatus). provided in a perforated hollow cylinder with a plurality of passage holes, at least one compression element disposed within the perforated hollow cylinder and extending in the radial direction of the perforated hollow cylinder along the inner wall of the perforated hollow cylinder; The present invention relates to such a device in which at least one material cutting element moves and slides on the outer wall of the perforated hollow cylinder.

Prior Art In order to reuse thermoplastic waste such as polyvinyl chloride, polyethylene, or polypropylene, it is usual to form it into a compressed granule with flowability beforehand, and to recycle the pulverized plastic waste. The larger the volume of the object, that is, the lower the density, the greater the need for it. This is particularly true in the case of plastic oils, which can only be recycled after being compressed into flowable granules.

For this purpose, the following installations are already known, in which the plastic waste is first crushed into slices, fritters or flakes in an impeller crusher and then fed pneumatically to a compression and granulation device. is publicly known. In this equipment, plastic slices are compressed into granules, which, after passing through pneumatic cooling and sorting equipment, are finally made into flowable granules.
Leave the facility in a more or less homogeneous state.

A device of this kind, especially for the recycling of polyethylene foil, is disclosed in the magazine "Plastic Bellator", May 1961 issue, page 370, which rotates about its axis. It has a perforated hollow cylinder, which is provided with radial passage holes for the material to be compressed. Two compression rollers that face each other and act as compression elements roll on the inner wall of this perforated hollow cylinder, and while the foil fritter (or foil slice) is compressed by these compression rollers, it is compressed into the perforated hollow cylinder. passes through the hole. In this case, the compression roller is provided with two distribution vanes. The purpose of this distribution vane is to distribute the foil fritters, which are fed into the perforated hollow cylinder by means of a coaxially arranged feed screw, onto the inner wall of the perforated hollow cylinder as evenly as possible. When the compression roller rolls on the inner wall of the perforated hollow cylinder, the foil fritter rolls into the passage hole of the perforated hollow cylinder, and other foil fritters are pushed in one after another. As a result, the compressed fibers or compressed rods pass through the passage hole while being compressed due to the action of compression heat and frictional heat, and as a result, the foil fritter is compressed more or less compressed and sticks to each other. The shape is ejected at the outer wall of the perforated hollow cylinder and cut to length by a fixed cutter sliding on the outer wall of the rotating perforated hollow cylinder.

A disadvantage of this known compaction and granulation device is that granules are obtained which are relatively inhomogeneous in terms of structure; for example, granules can consist of simply folded foil fritters or can be fused in a defined manner. It may also consist of parts that have been One of the foil fritters rolls into one of the passage holes of the perforated hollow cylinder, and the other foil fritters are pushed in one after another until the foil passes through the passage hole while being compressed. How often the fritters are processed by compaction rollers is more or less left to chance, and the aforementioned inconsistency of the granules depends precisely on this point. The foil fritter may be forced into the through hole during the first roller treatment, or it may be forced into the through hole after multiple roller treatments. It goes without saying that a foil fritter that has been subjected to multiple roller treatments has been subjected to a more intensive compression process than a foil fritter that is forced into the passage hole during the first roller treatment. This variation in the compression process causes the above-mentioned non-uniformity of the granule, and this non-uniformity causes problems during subsequent processing in the die-casting machine, extruder, or blower. be. Furthermore, in this known device, it is difficult to synchronize the material charging time and residence time with respect to each other, taking into account the properties of the material. Finally, because of the uneven compaction effect, the energy consumption is also relatively high in this known compaction and granulation device.

German Patent No. 1454873 has already disclosed the following method in order to eliminate at least the above-mentioned drawback of non-uniformity in the structure of the resulting granules. That is, the compression of the previously shredded waste film takes place between elements that generate frictional heat while the waste film is forced to pass through the passage hole only once. A compaction and granulation device suitable for this method and disclosed in German Patent No. 1 454 875 is rotatable relative to one another, is equipped with friction elements, is axially adjustable with respect to one another, and has material in the center. The friction element is preferably designed as a tooth-shaped projection. Although this known compression/granulation device can achieve sufficiently homogeneous compression, the compressed granules are not sent to the friction gap between both toothed disks as a predetermined granule, but rather are unevenly distributed. The disadvantage is that it is fed in the form of longer or shorter strands, which then have to be ground in a separate cutting granulator. The granules made in this way have a fairly uniform internal structure, but on the other hand, the shape is irregular due to the toothed disks and the cutting-type granulator installed separately behind these toothed disks. It is. Furthermore, the gap width between the toothed discs and/or their relative rotational speeds must be adjusted to correspond to the different properties of the various types of plastics obtained as waste.

Purpose The object of the present invention is to proceed from the above-mentioned prior art to a method which, regardless of the type and characteristics of the plastic waste to be treated, is suitable for structural consumption and energy consumption, and that the material is not susceptible to thermal damage. To provide a compression/granulation device that can always obtain uniform granules with high density and fluidity without overdoing the granules.

Configuration In order to achieve the above object, the present invention provides that the compression element is formed as a robust compression vane, and the working side of the compression vane, together with the inner wall of the perforated hollow cylinder,
A compression space is formed that narrows in a direction opposite to the direction of relative movement of the compression vane to the perforated hollow cylinder, and the compression space is fixed to the compression vane in the circumferential direction of the perforated hollow cylinder. The perforated hollow cylinder is closed by a compression member in contact with the inner wall, and the two annular walls connected to the perforated hollow cylinder partially close both end faces of the perforated hollow cylinder, causing compression. It is characterized by covering the front and rear surfaces of the space.

Actions and Effects Since the compression space that rotates relative to the perforated hollow cylinder gradually becomes narrower,
The plastic oil supplied to the perforated hollow cylinder and captured by the working side of the compression vane and drawn into the compression space by the relative movement of the compression vane is placed under an increasing compression, and this compression This continues until the compression force generated in the compression space exceeds the adhesive resistance of the plastic in the passage hole of the perforated hollow cylinder used as the forming tool. In this case, in addition to the compressive force, a considerably large shear force is generated within the compressed space. This shear force is due to the relative movement between the compression vanes and the perforated hollow cylinder, which creates a laminar tumbling flow of plastic within the compression space. Therefore, due to the strong friction between the plastics and between them and the surfaces forming the compression space, the plastics are rapidly and automatically heated and are thereby quickly brought to a homogeneous dough-like state, which The plastic is then discharged from the compression space under the appropriate pressure.

Once the above state is reached, the compression and shear forces in the compression space no longer increase (despite the compression space becoming increasingly narrow) and therefore the conversion of drive energy into heat no longer increases. . Such an equilibrium between the internal compression force and the resistance force in the passage hole always occurs at the same position in the compression space for the same type of plastic, i.e. when used as a specific compression tool to open the compression space. They always occur at equal intervals for the closed compression members in the circumferential direction of the hollow cylinder. This means that this position moves along the circumference of the perforated hollow cylinder synchronously with the relative movement of the compression space and the perforated hollow cylinder. In this way, an unnecessary supply of energy to the already sufficiently softened plastic is automatically avoided in the compression space, and thus not only a rapid plasticization of the plastic but also its unnecessary heating is prevented. , so that even if the melting point is reached or exceeded, the material will not be thermally damaged.

By the way, apart from the protection of this material from heat, the softening process of the plastic oil that takes place under automatic pressure and temperature regulation in the compression space provided according to the invention has no effect from a functional point of view. As you can see, it has an advantageous effect on the process within the compression/granulation equipment.
The plastic oil, which is merely softened in the above compression space, exerts its original compression effect for the first time in the passage hole of the perforated hollow cylinder while adhering to each other and fusing (sintering). Finally, it passes through the passage hole while being compressed by a compression member attached to the compression vane and closing the compression space in the circumferential direction of the perforated hollow cylinder. In this case, the compressive force required for the sintering process within the passage hole may be of a level corresponding to the passage resistance generated within the passage hole. The passage resistance of the softened plastic oil in the passage hole does not depend on the geometrical state of the plastic, and above all on the viscosity that corresponds to the degree of softening obtained at this very moment, so that it passes while being compressed. It goes without saying that the higher the viscosity of the plastic, the greater the compressive force and sintering pressure within the passage hole.

Finally, the relatively high viscosity of the plastic when passing through a perforated hollow cylinder also has functional advantages. This is because the filament-compacted plastic discharged from the passage hole can be easily granulated directly on the outer wall of the perforated hollow cylinder, i.e. without the need for prior cooling, only if the plasticity range is not exceeded. Because you can.

Therefore, softening of the plastic oil is absolutely necessary in order for the plastic oil to enter the passage hole and for the plastic oil to compress or stick together during the sintering process in the compression space. insofar as it takes place in compressed space. On the other hand, in order to ensure the necessary compaction and sintering pressure in the passage hole, and to subsequently cut the plastic material compressed into threads into flowable granules, the softening is kept to a minimum. It will be done.
Therefore, the compressed space formed according to the invention is
It serves to idealize and automatically suppress the change of state of the supplied plastic within the necessary limits, so that the actual compaction and sintering process that subsequently takes place in the passage hole, It also creates the physical conditions for the subsequent cutting process into granules.

In this case, the changes in the state of the plastic that occur in the compression space provided according to the invention are not exhausted during the above-mentioned centrally and automatically regulated plasticizing process. Rather, an intensive mixing process is carried out by the tumbling flow of plastic forced by the relative movement between the compression vanes and the perforated hollow cylinder, which passes through the inner wall of the perforated hollow cylinder. This is additionally facilitated by the fact that the provision of the holes increases the roughness of the perforated hollow cylinder and thus increases the frictional effect. Moreover, the sharp edges on the inner surface of the passage holes shear off small parts of the already softened plastic as it continually advances over this edge, and in this way it is forced into the compression space. It also acts as a crushing element, insofar as it supports to a considerable extent the mixing and homogenization processes that proceed simultaneously with the plasticization process.

According to the invention, therefore, the compression vane and the perforated hollow cylinder, in addition to their conventionally known and effective functions as compression elements and forming tools, can therefore:
Furthermore, it also produces the mixing, plasticizing and homogenizing effects of the plastic necessary for the actual compaction and sintering process in the passage holes of the perforated hollow cylinder. In this case, technological pre-treatments are carried out in order to automatically adapt the two above-mentioned elements, which are functionally integrated with each other, that is, they influence, cooperate and complement each other, to the particular properties of the plastic. This is realized in that the active side surface of the compression vane formed according to the invention forms the above-mentioned continuously tapering compression space with the inner wall of the perforated hollow cylinder due to its shape.

Embodiment Next, one embodiment of the present invention will be described with reference to the accompanying drawings.

In the compaction and granulation equipment known per se in its basic construction, which is diagrammatically illustrated in FIG.
A granulation device 9 is provided. The pre-cleaned plastic waste to be treated is first sent via a material inlet 1 to an impeller crusher 2, from which the pre-crushed material is passed through a suction pipe 3 to an impeller crusher 2. The air is sent to the blower 4 of No. 1. This blower 4
sends the pre-crushed material to a separator 6 via a pressure pipe 5. The material separated in the separator 6 then falls into a collection container 7 from where it is transferred by a transfer device 8 to the intake of a compression and granulation device 9 formed according to the invention. sent to.

The material compressed and granulated into granules in the compression/granulation device 9 falls downward into the suction pipe 10 . A suction pipe 10 delivers the material to a granule separator 11. After granule separation 11 is also used as a cooling and washing device. If the granules flowing into the granule separator 11 contain uncompressed parts or dust,
These uncompressed parts or dust are discharged via the suction pipe 14 and are fed again after separation 6 via the return pipe 16 by a second blower 15 and thus to the compression and granulation device 9. be done. Finally, it is cleaned and
The dedusted, compressed and granulated material is removed from the granule separator 11 in the direction of the arrow 13 by a delivery device 12 in the form of flowable granules.

FIG. 2 is a longitudinal sectional view of the compression/granulation device 9 according to the invention. Inside the housing 23 is a drive shaft 20 driven by a gear motor (not shown).
is provided. Shaft extension 20' of drive shaft 20
A boss 21 is fixed to the housing, and the boss 21 is firmly connected to the compression vane 19 and the feed screw 18. Therefore, the drive shaft 20, the boss 21, the compression vane 1
9. The feed screw 18 forms a rotating unit which is supported in a cantilevered manner on a bearing 22. The bearing 22 is arranged in a housing rear passage 24 which is formed into a tubular shape.

The housing front passage for the feed screw 18 is provided with a housing cover 28 which can be pivoted outwards.
It is located inside. The housing cover 28 is
Supply screw 18 via mounting flange 29
casing and the material inlet 17 of the feed screw.

The compression vane 19 is surrounded by a perforated hollow cylinder 34 arranged concentrically with respect to the drive shaft 20 . The perforated hollow cylinder 34 is provided with passage holes 48 (FIG. 3) uniformly distributed over its entire surface and radially oriented. The perforated hollow cylinder 34 provided with the passage hole 48 is partially closed at both end faces by two annular walls, namely a rear annular wall 26 and a front annular wall 27.
The distance between the rear annular wall 26 and the front annular wall 27 in the central axis direction of the perforated hollow cylinder 34 is smaller than the diameter of the perforated hollow cylinder 34 in the illustrated example, so that a disc-shaped internal space is formed. has been done. The compression vane 19 rotates within this internal space. The rear annular wall 26 is fixed to a housing flange 25 formed integrally with the tubular housing rear passage 24, while the front annular wall 27 is connected to a housing cover 28 which is pivotable on its outer axis. Both annular walls 26, 27 form cooling chambers 26' and 2
7', and a cooling medium is supplied to these cooling chambers 26' and 27' through a duct 30 provided in the rear penetration part 24 of the tubular housing or by a pipe 31 connected to a water supply hose. be done. As a packing portion between the rear annular wall 26 and the boss 21, a threaded packing fin 32 is used. Furthermore, an additional packing ring 33 is provided in the area of the bearing 22.

Two cutters 35 serving as material cutting elements are arranged facing each other on the outer wall of the perforated hollow cylinder 34, and these cutters 35 are each fixed to a cutter holder 36 so as to be adjustable in position. Both cutter holders 36 are mounted on bosses 37, which are supported on the housing rear passage 24 by bearings 38. The boss 37 of the cutter holder has a sprocket 39,
A drive chain (not shown) rotates via the sprocket 39, and the drive chain is driven via another sprocket attached to the gear motor.

3 and 4 show the compression vane 19 and the perforated hollow cylinder 34 surrounding it. In the embodiment described here, the two compression vanes 19 rotating in the direction of the arrow 47 (direction of relative movement of the compression vanes 19 with respect to the perforated hollow cylinder 34) are arranged offset from each other by 180°. The working side surface 19' of the compression vane 19 extends according to a continuously curved curve, i.e. the working side surface 19' along with the inner wall of the perforated hollow cylinder 34 runs in the direction opposite to the arrow 47. It extends in the form of a continuously narrowing sickle-shaped compression space 40, in which case a groove 43 can be provided on this active side 19'. A compression member 44 is fixed to the outer end of each compression vane 19, and the compression member 44 is positionally adjustable toward the inner wall of the perforated hollow cylinder 34. The compression member 44 has a compression surface 45 that contacts the inner wall of the perforated hollow cylinder 34 . Furthermore, the compression vane 19 is provided with a pocket-shaped recess 41 in a portion facing the supply screw 18 and facing the outlet of the screw spiral portion 18' of the supply screw, and has a reduced thickness in an outer region 42. It is formed by

The compression and granulation device according to the invention operates as follows.

The pre-shredded plastic material is fed to the material intake 17 via a suitably controllable transfer device 8 and captured by a feed screw 18 which pre-compacts and mixes the material. Then, it is supplied to the perforated hollow cylinder 34. In the perforated hollow cylinder 34 the material is
The compression vane 19 is press-fitted into the free intermediate space in the direction of rotation of the arrow 46, and at this time the compression vane 1
Pocket-shaped recess 41 provided on the end surface of 9
has a favorable effect on the distribution of the material. The plastic is then captured by the active side 19' of the compression vane 19 and drawn into the continuously narrowing sickle-shaped compression space 40. In this case, the mechanism of action described in detail above has already stopped. The mechanism of action is that the plastic is finally discharged in the form of a sintered homogeneous compressed thread around a perforated hollow cylinder 34, and the threaded material is discharged in a direction opposite to the direction of arrow 47. The cutter 35 rotates to cut the bar into short pieces of the same length.

In order to avoid uncontrollable heat accumulation in the mechanical elements of compaction and granulation equipment and this heat having undesirable effects on the processed material, the heat generated by the conversion of drive energy must be The parts are constantly removed from the compression space by means of a cooling medium flowing through the cooling chambers 26' and 27', so that the process proceeds isothermally during continuous operation.

The compaction and granulation device according to the invention can be used to adjust the conversion of the drive energy required for plasticization into heat in accordance with the properties of the type of plastic being treated in each case, so that it can be used to process different heat It can be used in a wide range of plastics, depending on the particular case, by simply replacing the perforated hollow cylinder and only making minor structural readjustments. However, in most cases it is sufficient to control the material charge in each case as a function of the received driving energy.

Furthermore, the compaction and granulation device according to the invention provides a method for intensively mixing and homogenizing the materials before sintering in the compaction space configured according to the invention, thereby producing heat particles with different chemical composition and appearance. Not only can plastic plastics alone be processed, but thermoplastics can also be granulated by mixing high proportions of non-thermoplastic plastics. Heat-sensitive organic materials are also suitable for this purpose, since automatic temperature control takes place during plasticization.

Due to its properties and functions, the compaction and granulation device according to the invention is particularly suitable for the reprocessing of plastic wastes such as: That is, wastes whose sources change frequently and whose physical properties vary due not only to their chemical composition but also to the relatively initial loading during production and use. . The compacting and granulating device according to the invention therefore makes it possible to process not only thermoplastic plastic oils, but also plastic wastes of fibrous and foam structure, while also forming plastic layers containing support substances into compacted granules. It can also be easily processed.

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing the known configuration of the entire compression/granulation equipment, Fig. 2 is a vertical sectional view taken along the line--line of Fig. 1 of the compression/granulation equipment according to the present invention, and Fig. 3 2 is an enlarged cross-sectional view taken along the line - in FIG. 2, and FIG. 4 is an enlarged longitudinal sectional view taken along the line - in FIG. 3. 18... Supply screw, 19... Compression vane,
19'... Working side of compression vane, 20... Drive shaft, 26, 27... Annular wall, 26', 27'... Cooling chamber, 34... Hollow cylinder with holes, 35... Cutter, 36, 37 ... cutter holder, 4
0... Compression space, 44... Compression member, 48... Passing hole.

Claims (1)

[Claims] 1. An apparatus for compressing and granulating thermoplastic waste, wherein the material to be treated is
provided in a perforated hollow cylinder with a plurality of passage holes, at least one compression element disposed within the perforated hollow cylinder and extending in the radial direction of the perforated hollow cylinder along the inner wall of the perforated hollow cylinder; In the device in which at least one material cutting element moves and slides on the outer wall of the perforated hollow cylinder, the compression element is formed as a solid compression vane 19 and the working side 1 of the compression vane
9′ together with the inner wall of the perforated hollow cylinder 34;
A compression space 40 is formed that narrows in the direction opposite to the relative movement direction 47 of the compression vane 19 with respect to the perforated hollow cylinder 34, and the compression space 40 is formed in the circumferential direction of the perforated hollow cylinder. It is closed by a compression member 44 fixed to the compression vane 19 and in contact with the inner wall of the perforated hollow cylinder 34, and the two annular walls 26, 27 connected to the perforated hollow cylinder 34 are closed by the perforated hollow cylinder 34. Both end surfaces of the cylinder 34 are partially closed, and the compression space 40 is
A device characterized in that the front and rear surfaces of the device are covered. 2. Device according to claim 1, characterized in that the compression space 40 is continuously narrowed and is approximately sickle-shaped. 3. The distance between the annular walls 26 and 27 in the central axis direction of the perforated hollow cylinder 34 is smaller than the diameter of the perforated hollow cylinder 34, and as a result, a disk-shaped internal space is formed, and the compression vane is formed within the internal space. 1
3. Device according to claim 1, characterized in that 9 rotates relative to the interior space. 4. Claim 1, characterized in that the working side surface 19' of the compression vane 19 is provided with a groove 43.
Apparatus according to any one of clauses 3 to 3. 5. The perforated hollow cylinder 34 is stationary and the compression vanes 19 and the material cutting elements 35, 36, 37 rotate. Device. 6. Device according to claim 1, characterized in that the compression vanes 19 are designed as two symmetrical vanes. 7. Device according to any one of claims 1 to 6, characterized in that the material cutting element consists of two cutters 35 facing each other. 8. Device according to any one of claims 1 to 7, characterized in that the passage holes 48 of the perforated hollow cylinder 34 extend in the radial direction of the perforated hollow cylinder. 9. Claim 1, characterized in that the passage hole 48 of the perforated hollow cylinder 34 is cylindrical.
Apparatus according to any one of clauses 8 to 8. 10. Device according to any one of claims 1 to 9, characterized in that each passage hole 48 of the perforated hollow cylinder 34 is formed in the same shape as one another. 11 The compression member 44 that closes the compression space 40 in the circumferential direction of the perforated hollow cylinder has a compression blade 19 whose position can be adjusted in the radial direction of the perforated hollow cylinder 34.
11. Device according to any one of claims 1 to 10, characterized in that it is fixed to. 12. Claims 5 to 1 are characterized in that a supply screw 18 is provided for supplying the material, and the supply screw 18 is coupled to a drive shaft 20 of the compression vane 19 in a manner that is non-rotatable relative to the drive shaft 20 of the compression vane 19.
Apparatus according to any one of clauses 1 to 1. 13 The compression vane 19 is placed on the supply screw 18 side and the screw helical portion 18' of the supply screw
13. The device according to claim 12, further comprising a pocket-like recess 41 in a portion facing the outlet. 14 The cutter 35 is a perforated hollow cylinder 34
According to any one of claims 7 to 13, characterized in that the cutter holder 36, 37 rotates concentrically around the cutter holder 36, 37 and is driven via a transmission. The device described. 15. Claim 1, characterized in that the annular walls 26, 27 partially covering the front and rear sides of the compression space 40 are provided with chambers 26', 27' for the heat exchange medium. 15. The device according to any one of clauses 1 to 14.