Heavy-duty vortex internals for processing plastic particulate material and related methods

Abstract

The invention relates to a heavy-duty in-vortex device (1) for processing plastic particulate material, comprising a vibrating trough (10) for receiving plastic particles, the vibrating trough having a trough base (11) and two opposite side walls (12a, 12b), the length of the vibrating trough (10) in a longitudinal direction (a) being greater than the maximum height and width of a trough cross-section perpendicular to the longitudinal direction; at least two vibration exciters (20) for generating a vibration excitation, the vibration excitation having a transverse component (y) perpendicular to a plane, the plane being formed by the longitudinal direction (a) and a vertical direction (z); and at least two trough supports (31) which are spaced apart from one another in the longitudinal direction (a) of the vibrating trough (10), each supporting the trough base (11) and the side walls (12a, 12b) from the outside and also spanning the vibrating trough (10) on the side opposite the trough base (11), in each case one of the vibration excitators (20) being fastened to at least two of the trough supports (31). The invention further relates to a method for crystallizing plastic particles having a tendency to stick together.

Description

[0001] This invention relates to a vortex trough device for processing plastic granules.

[0002] Some plastic granules undergo post-granulation treatment, particularly thermal treatment, after actual granulation to alter their structure. For example, polylactic acid (PLA) granules and polytetrafluoroethylene (PET) granules are initially obtained from the granulation process in an amorphous state. The amorphous granules are then transformed into a state that is at least partially crystalline during the post-processing steps, a process also known as crystallization. This results in an increased arrangement of molecular chains.

[0003] Temperature control plays a crucial role in crystallization. On the one hand, amorphous particles must be brought to or maintained at the corresponding reaction temperature. However, on the other hand, some particles (such as PLA particles, PET particles, and PU particles) tend to agglomerate during the transition phase.

[0004] PLA granules typically leave the granulator at temperatures ranging from 80°C to 120°C. The individual PLA particles initially have extremely sticky surfaces. Due to their glass transition temperature of approximately 60°C to 80°C and crystallization temperature of approximately 90°C, they are very close to each other, making the drying and crystallization of PLA difficult, as it is essential to prevent the particles from sticking together during crystallization.

[0005] Furthermore, PET particles are already sticky at the reaction temperature required for crystallization, which is approximately 80°C to 170°C. Therefore, to avoid particle aggregation, these particles must move during crystallization. The tendency to stick together decreases as the degree of crystallization increases.

[0006] Many technical solutions for crystallizing such particles are known from existing technology.

[0007] The newer method is based on the consideration that, immediately following the downstream crystallization process, the pre-dried, warm granules obtained from granulation are subjected to vibrational excitation. This vibrational excitation prevents the particles from agglomerating. Simultaneously, the process heat stored within the particles can be used for crystallization, eliminating the need for additional heating. In contrast, to prevent agglomeration, granules, for example, temporarily stored in silos, must first be cooled and then reheated for crystallization.

[0008] EP1924414B1 discloses a post-treatment of particles within their crystallization reaction temperature range, utilizing a known vortex tank apparatus. Such an apparatus includes a vibrating tank for receiving the particles and at least one vibration exciter for vibrating the tank. The vibration excitation occurs in different transverse components perpendicular to a plane that includes the longitudinal and vertical directions of the vibrating tank.

[0009] This special type of vibration excitation causes the particles to move spirally in the longitudinal direction of the vibrating trough, a characteristic feature of vortex trough devices. Due to the vibration excitation in the transverse direction, the particles move upward on the sidewalls of the vibrating trough and then slide back into the trough above the subsequently rising particles upon reaching the vertical wall section. This results in a continuous, uninterrupted flow of particles with high interaction between them, allowing these particles to exchange process heat. This achieves not only a very narrow residence time spectrum for the particles during the crystallization stage but also a very uniform temperature profile, which is beneficial for product quality. Such effects are not achievable using conventional vibrating conveyors, screening machines, or screw conveyors because the spiral movement of the particles (with their high interaction) is impossible in this case.

[0010] The vortex groove device proposed by the applicant of EP1924414B1 is only suitable for small product production rates due to its design. As the product volume increases, a high inertial force is generated transversely to the vertical and longitudinal directions of the vibrating groove due to the lateral component required for the helical movement used to generate the product.

[0011] The purpose of this invention is to achieve a high product productivity by utilizing a vortex tank device during the crystallization of plastic particles.

[0012] This objective is achieved by the heavy-duty vortex trough device according to claim 1. The device includes a vibrating trough for receiving plastic granules, the trough having a base and two opposing sidewalls, wherein the length of the vibrating trough in the longitudinal direction is greater than the maximum height and width of the trough cross-section perpendicular to the longitudinal direction; at least two vibration exciters for generating vibration excitation having a transverse component perpendicular to a plane formed by the longitudinal and vertical directions; at least two trough supports spaced apart from each other in the longitudinal direction of the vibrating trough, each supporting the base and the sidewalls from the outside, and also bridging the vibrating trough on the side opposite the base; wherein, in each case, one vibration exciter is fastened to at least two of the trough supports.

[0013] This configuration has the potential to handle product volumes of 3 to 10 tons for the first time without loss of product quality. In this case, a speed of 30 kgm / s can be achieved. 2 Up to 60 kgm / s 2 The acceleration.

[0014] Due to the special design of the groove support, high inertial forces in the lateral direction can be well controlled.

[0015] Advantageous embodiments of the present invention constitute the content of the other claims.

[0016] Therefore, for a particularly stable design, the groove supports can each form a closed loop that radially surrounds the vibration groove.

[0017] Preferably, the vibration groove passes substantially perpendicularly through the groove support, such that the longitudinal direction of the vibration groove and the main extension plane of the corresponding groove support form a minimum angle within the range of 75° to 88°. Therefore, the groove support substantially supports the vibration groove in the plane of its cross-section.

[0018] In one variation, the main extending plane of the groove support is a vertical plane that extends generally transversely to the longitudinal direction of the vibration groove. Several groove supports may be placed parallel to each other in the longitudinal direction of the vibration groove.

[0019] In another variation, the groove support has a one-piece support plate with a constant wall thickness, in which the passage opening for the vibration groove is formed. Such a plate can be manufactured effortlessly. If necessary, it can be further reinforced at its edges with flange plates.

[0020] Furthermore, the base of the vibrating trough can be inclined downwards in the longitudinal direction from the feed end to the outlet end. This facilitates the conveying of particles through the vibrating trough in the longitudinal direction. Preferably, product conveying is caused solely by new feed at the feed end, but it can also be assisted by vibration. However, the surface vibration excitation component remains consistent in the transverse direction, avoiding high acceleration of particle particles in the longitudinal direction.

[0021] In a preferred variant, the base of the vibration groove is inclined to a horizontal plane in the longitudinal direction at an angle ranging from 2° to 15°.

[0022] According to another variant, the cross-section of the vibratory trough between the inlet and outlet ends has no obstructions. This promotes mixing in the product stream and is beneficial for uniform product quality.

[0023] The groove support may be incorporated into a cage-like shell structure, which on the one hand has high rigidity, but on the other hand requires a small amount of material and is therefore relatively lightweight. For this purpose, according to another variation, adjacent groove supports are connected to each other in the longitudinal direction of the vibration groove by at least three longitudinal members.

[0024] It has also been shown that the direction of the force of the vibration excitation plays a crucial role in achieving high product quality within the vibratory groove. Preferably, furthermore, regarding the overall height and support of the device according to the invention, the vibration exciter is positioned above the vibratory groove and preferably in a region above or near one of the sidewalls, arranged in such a way that the line of action of the vibration excitation force of the respective vibration exciter extends a distance to the upper edge of the sidewall on one side of the vibration exciter, this distance being at most 20% of the width of the vibratory groove between the sidewalls, preferably at most 10%. This arrangement of the vibration exciter also achieves simple thermal insulation of the vibratory groove from below.

[0025] Preferably, the line of action of the vibration excitation force of the corresponding vibration exciter is consistent with and matches the width of the vibration groove, such that it intersects the groove base upstream of the center of the groove base in the transverse direction of the vibration groove.

[0026] In another variation, the line of action of the vibration excitation of the corresponding vibration exciter in a vertical plane including the lateral direction preferably forms an angle between 25° and 50° with the base of the groove. Angles that are too flat or too steep prevent the desired rise of particles on the sidewalls and the formation of significant helical movement or eddies in the vibration groove.

[0027] To promote the spiral movement of particles in the vibrating groove, the base of the groove has a straight portion in the plane of the groove cross-section, which is inclined downward toward the horizontal direction away from the vibration exciter, and in particular, can be inclined to this horizontal direction at an angle of 2° to 15°.

[0028] With a larger groove width, the straight portion can be divided into two or more straight segments by one or more beads extending in the longitudinal direction of the vibrating groove. In this case, the average total inclination is preferably maintained within the aforementioned range of 2° to 15°.

[0029] In this regard, it is also advantageous that the sidewalls of the vibration groove are each joined to the groove base via a curved portion, wherein the radius of curvature of the curved portion on the vibratory actuator side is greater than the radius of curvature of the curved portion on the opposite side. Due to the reduced radius of curvature on the side away from the vibratory actuator, the usable capacity of the vibration groove is also increased.

[0030] Preferably, the ratio of the radius of curvature of the curved portion on one side of the vibration exciter to the radius of curvature of the curved portion on the opposite side is greater than 2, more preferably greater than 5.

[0031] Furthermore, the ratio of the radius of curvature of the curved portion on one side of the vibration exciter to the width of the vibration groove between the sidewalls should be selected as little as possible to be less than 0.3 and greater than 0.1.

[0032] As already mentioned, the radius of curvature of the curved portion on one side of the vibration exciter is larger, in particular significantly larger, than the radius of curvature of the curved portion on the opposite side. In another variation, this larger radius of curvature is chosen such that it is at least one-quarter of the maximum groove depth of the vibration groove (i.e., the height of the vibration groove measured on its inner side).

[0033] The target filling volume of the vibration groove is greater than 50% of the groove cross-section.

[0034] The heavy-duty vortex tank apparatus explained above is particularly suitable for performing a method for crystallizing plastic granules that tend to agglomerate. The method involves loading plastic granules into a vibrating tank according to any one of the preceding claims, the plastic granules having a temperature above their glass transition temperature range when fed; exciting the vibrating tank by the vibration exciter, in which the plastic granules in the vibrating tank undergo helical movement, wherein the residence time of the plastic granules in the vibrating tank is 20 to 60 minutes, and the vibrating tank is filled with plastic granules at least 50% of its cross-section. In this case, the feeding of the granules is preferably performed continuously. However, batch operation is also possible.

[0035] The present invention will be explained in more detail below with reference to the embodiments shown in the accompanying drawings, wherein:

[0036] Figure 1 A three-dimensional view of a heavy-duty vortex groove device according to an embodiment of the present invention.

[0037] Figure 2 According to Figure 1 Another three-dimensional view of the heavy-duty vortex flume device.

[0038] Figure 3 According to Figure 1 A cross-sectional view of a heavy-duty vortex groove device, and

[0039] Figure 4 A detailed view of the groove base of a variant with a beaded straight section.

[0040] Figures 1 to 3 The embodiments illustrate a device in the form of a heavy-duty vortex groove apparatus 1, which is suitable for and configured for crystallizing plastic particles. The technical principles of the vortex groove on which the present invention is based are explained in EP1924414B1, the contents of which are expressly incorporated herein by reference.

[0041] In the diagram and in the explanation below, reference is made to the Cartesian coordinate system xyz, where x represents the horizontal axis, y represents the horizontal axis orthogonal to x, and z represents the vertical axis orthogonal to both x and y. The vertical axis z coincides with the direction of gravity. Therefore, the x-axis and y-axis span the horizontal plane xy, which is perpendicular to the direction of gravity.

[0042] For heavy-duty vortex flume devices, another Cartesian position coordinate system abc is also referenced, where a defines the longitudinal axis of the device, b defines the transverse direction of the device orthogonal to a, and c defines the horizontal direction orthogonal to both a and b. The transverse direction b coincides with the y-axis. If the transverse direction is referred to below, it should be understood as defined above. The longitudinal axis a may coincide with the x-axis, and the vertical direction c coincides with the z-axis. However, typically, the longitudinal axis a and the vertical direction z are slightly tilted toward the corresponding axes x and z, as will be explained in further detail below.

[0043] The heavy-duty vortex trough device 1 according to the invention initially includes a vibrating trough 10 for receiving plastic particles. The vibrating trough 10 is designed as an elongated trough with a generally U-shaped cross-sectional profile. Thus, it has a trough base 11 and two opposing sidewalls 12a and 12a, which are connected to each other through the trough base 11.

[0044] Preferably, the cross-sectional profile is constant along the length of the vibration groove 10. Furthermore, this cross-sectional profile has no obstructions between its ends in the longitudinal direction a.

[0045] The sidewalls 12a and 12b may be oriented to be generally parallel to each other and have a constant distance from each other in the longitudinal direction, preferably in the range of 1000 mm to 3000 mm, more preferably in the range of 1500 mm to 2500 mm. They extend in the longitudinal direction a and the vertical direction c of the vibrating groove.

[0046] The sidewalls 12a and 12b are each joined to the groove base 11 via a curved portion 13a or 13b.

[0047] The base 11 of the groove can be designed as a generally planar surface in the horizontal plane xy. However, it is preferably slightly inclined in the longitudinal direction a and / or the transverse direction b of the vibration groove 10.

[0048] Therefore, the base 11 of the vibrating trough 10 can be inclined downward in the longitudinal direction a from the feed end 14 to the outlet end 15 of the vibrating trough 10 to facilitate the passage of particles from the feed end 14 to the outlet end 15. In particular, when the particle feeding in the vibrating trough 10 is achieved solely by feeding particles into the vibrating trough 10, i.e., there is no need to convey a vibration support. However, in its improved form, the particles can also vibrate during feeding in the longitudinal direction a. The latter also includes the possibility of reversing the feeding direction of the particles in the vibrating trough 10.

[0049] Preferably, the tilt in the longitudinal direction a is performed at an angle α relative to the horizontal plane xy, ranging from 2° to 15°. Regarding the coordinate system defined above, this means that the longitudinal axis is set relative to the x-axis and the aforementioned angle α.

[0050] The inclination of the groove base 11 in the transverse direction b is shown in Figure 3 The groove base 11 has a straight portion, i.e., a plane bc, in the plane of the groove cross-section, inclined from the first sidewall 12a to the second sidewall 12b. The straight portion inclines downward in the plane bc of the groove cross-section to the horizontal direction b. The straight portion of the groove base 11 is preferably inclined at an angle β, particularly relative to the horizontal direction b, between 2° and 15°. Therefore, the groove base 11 represents an inclined plane in the transverse direction b of the vibrating groove 10.

[0051] In an improved embodiment, the straight portion of the groove base 11 extending in the longitudinal direction a of the vibration groove 10 is divided into two or more straight segments 11b, 11c by one or more beads 11a, the straight segments 11b, 11c being at an angle to each other. Figure 4 The cross-section of the curved groove base 11, having two straight segments 11b and 11c, is shown by way of example. In this case, the average total inclination β (which is measured between the groove base 11 and the junction of the curved portions 13a and 13b) is preferably kept in the range of 2° to 15°. The bends of the groove base 11 achieve a reinforcing effect.

[0052] As already mentioned, the vibration grooves 12a and 12b are each joined to the groove base 11 via bent portions 13a and 13b. In this case, it is also as follows Figure 3 As shown, the radius of curvature r of the curved portion 13a on one side a The radius of curvature r of the curved portion 13b on the opposite side is greater than b In the region of the curved portion 13a on the first side, eddies are formed within the particles. The smaller radius of curvature r on the opposite side... b A large filling volume in the vibratory trough 10 is advantageous, thus enabling high product output.

[0053] Larger radius of curvature r a The depth is selected such that it is at least one-quarter of the maximum groove depth of the vibration groove 10 (i.e., the height of the vibration groove 10 measured on its inner side).

[0054] The radius of curvature r of the curved portion 13a on the first side a The radius of curvature r of the curved portion 13b on the opposite side b The ratio is greater than 2, more preferably greater than 5.

[0055] For a groove width of 1800 mm, the particularly suitable radius of curvature r of the curved portion 13a on the first side is... a It falls within the range of 180mm to 450mm.

[0056] Regarding the net width w of the vibration groove 10 between the sidewalls 12a and 12b (i.e., its extension in the lateral direction b or y), the radius of curvature r of the curved portion 13a on the first side a The ratio of the width of the vibration groove 10 to the width of the vibration groove 10 is preferably less than 0.25 and / or greater than 0.1.

[0057] Typically, the net width w is chosen to be greater than the groove depth t.

[0058] The device 1 according to the invention further includes at least two vibration exciters 20 for generating vibration excitation on the vibration groove 10, wherein the vibration excitation has a component in the transverse direction b or y. For the formation of vortex or helical movement of particles about an axis parallel to the longitudinal direction a, this transverse component of the vibration excitation is decisive in the vibration groove 10, taking into account the structure of the cross-sectional profile of the vibration groove 10. Furthermore, the vibration excitation may include a component in the vertical direction z or the height direction c. In contrast, the proportion in the longitudinal direction a or the x-axis direction can be neglected.

[0059] Multiple vibration exciters 20 can be designed, for example, as directional exciters, coupled to each other so that excitation through all vibration exciters 20 is performed synchronously. However, other types of exciters are also feasible.

[0060] The vibration exciter 20 is not directly attached to the vibration groove 10, but is attached to the cage-like outer shell structure 30, which will be explained in more detail below and carries the vibration groove 10.

[0061] The outer casing structure 30 is based on two or more slot supports 31, which are preferably arranged in parallel sequence, i.e., in the longitudinal direction a of the vibration groove 10. In this case, the slot supports 31 are spaced apart from each other, such as... Figure 1 and Figure 2It can be clearly seen that the groove support 31 can be fabricated as an initial independent component. In this example, three groove supports 31 are shown by way of example. However, the number can also be selected to be less or more, depending on the length of the vibration groove 10.

[0062] The outer shell structure 30 also has longitudinal members 32, through which adjacent slot supports 31 are rigidly connected to each other. In this example, three longitudinal members 32 are provided, extending laterally into the vibration slot 10, preferably in the x-direction, to connect at least two adjacent slot supports 31, or optionally, to connect all slot supports 31. The longitudinal members 32 may be rod-shaped or strip-shaped. In one variation, these longitudinal members 32 have a constant cross-sectional profile. In particular, the longitudinal members 32 may also be designed with a hollow profile.

[0063] The outer casing structure 30 is supported against the base plate by springs 40. Springs 40 are preferably arranged on at least some slotted support members 31.

[0064] The vibration exciter 20 is preferably located on the groove support 31 and above the vibration groove 10, preferably above the side wall 12a on the first side, or to some extent laterally located outside it.

[0065] For the simultaneous processing of a large number of particles on the order of 3t to 10t in the vibrating tank 10, the tank support 31 is designed in a special way.

[0066] The cross-section of the groove support 31 is in Figure 3 As clearly shown in the diagram, the groove support 31 is rigidly connected to the vibration groove 10. Specifically, the groove support 31 has two vertical supports 31a and 31b, which extend vertically upward from the lower base portion 31c. The vertical supports 31a and 31b are connected to each other via a support portion 31d, such that the passage opening 33 of the vibration groove 10 is formed between said portions 31a and 31d. The groove support 31 has its main extensions in the directions of the y-axis and z-axis; that is, its extension in the x-direction is relatively small relative to these main extensions, making it suitable for description as disc-shaped or plate-shaped.

[0067] like Figures 1 to 3 As can be seen, the groove support 31 supports the groove base 11 and sidewalls 12a and 12b of the vibration groove 10 from the outside. Therefore, the vertical supports 31a and 31b rest against the sidewalls 12a and 12b of the vibration groove from the outside. Similarly, the groove base 11 rests against the lower base portion 31c.

[0068] Furthermore, the groove support 31 spans the vibration groove 10 on the side opposite to the groove base 11. Therefore, the support portion 31d that connects the vertical pillars 31a and 31b to each other extends above the vibration groove 10 in the lateral direction b or y.

[0069] In this example, each of the groove supports 31 forms a closed loop that radially surrounds the vibration groove 10.

[0070] In this example, the vibration groove 10 passes through the groove support 31 approximately vertically, that is, the longitudinal direction a of the vibration groove 10 and the main extension plane xy of the corresponding groove support 31 together form a minimum angle in the range of 75° to 90°.

[0071] Therefore, a very stable mounting of the vibration groove 10 on the housing structure 30 is achieved, and the housing structure 30 can then be designed to be relatively lightweight. In particular, any widening or narrowing of the vibration groove 10 in the lateral direction b is prevented.

[0072] In one variant, each of the groove supports 31 has an integral support plate 34 with a constant wall thickness, and the passage opening 33 of the vibration groove 10 is formed in the integral support plate 34. Additional reinforcement can be easily achieved by welding a flange plate 35 to the outer edge of the support plate 34.

[0073] Instead of the integrated support plate 34, the ring structure of the groove support member 31 that directly supports the vibration groove 10 can also be assembled from several individual parts, particularly by welding.

[0074] In addition, a groove support 31 can be manufactured as a casting.

[0075] The vibration exciter 20 is arranged in a region above the groove support 31 of the vibration groove 10 and above or near one of the side walls 12a, such that the line of action k of the vibration excitation force of the corresponding vibration exciter 20 extends a certain distance to the upper edge 12c of the side wall 12a on one side of the vibration exciter, the distance being at most 20%, more preferably at most 10%, of the width w of the vibration groove 10 between the side walls 12a and 12b.

[0076] The line of action k of the vibration excitation force of the corresponding vibration exciter 20 intersects the groove base 11 upstream of the center of the groove base 11 in the transverse direction b or y of the vibration groove 10. This promotes the formation of eddies in the region of the more gently curved portion 13a on one side of the vibration exciter in the vibration groove 10 and ensures a large number of collisions between the particles to be processed.

[0077] Furthermore, the force line k of the vibration excitation of the corresponding vibration exciter 20 in the vertical plane yz, including the lateral direction b or y, forms an angle γ with the groove base 11, which is in the range of 25° to 50°.

[0078] The aforementioned heavy-duty vortex trough device 1 can simultaneously process particles weighing 3 to 10 tons without loss of product quality, with an acceleration value of up to 30 kgm / s². 2 Up to 60 kgm / s 2 Within this range, this ensures that the particles do not stick together.

[0079] In this example, the target filling amount of the vibrating trough 10 can be greater than 50% of the trough cross-section, that is, a good utilization rate of the particle processing space is achieved.

[0080] Due to the radial encirclement of the groove-shaped vibration groove 10, the groove support 31 is particularly well-suited to absorb forces introduced in the y-axis direction, which is perpendicular to the product flow direction. These forces are very high in cases of large product fill volumes and can be further amplified by the dynamic excitation of the product, particularly by the formation of agglomerates within the product (which cannot be ruled out).

[0081] The achievable width of the vibration groove 10 is approximately 1000 mm to 3000 mm. In this case, a construction length of 5000 mm to 10000 mm is possible.

[0082] This takes into account the fact that, in the case of certain plastics, increasingly higher performance is desired, namely, product capacity over a roughly constant residence time; however, for installation and cost reasons, the number of vibratory troughs used in series should be kept as limited as possible to a maximum of three vortex trough units.

[0083] The housing structure 30 supporting the vibration groove 10 includes several preferred disc-shaped groove supports 31, each groove support 31 radially surrounding the groove-shaped vibration groove 10 and simultaneously absorbing the force introduced by the vibration exciter 20. The housing structure is designed to support high lateral forces while remaining relatively lightweight and easy to manufacture.

[0084] The heavy-duty vortex tank apparatus 1 described above is particularly suitable for performing a method of crystallizing plastic particles, such as PLA, PET, or PU, that tend to agglomerate together. For this purpose, the vibrating tank 10 of the heavy-duty vortex tank apparatus 1 is loaded with plastic particles that are heated during feeding, i.e., particularly having a temperature higher than their glass transition temperature within the range of their crystallization reaction temperature.

[0085] In particular, to save energy, the raw material particles can be sourced directly from the pelletizing unit without prior cooling. However, this means that, given limited space, sufficient space must be available for one or more subsequent vortex troughs, which is extremely important for a compact design that allows for high throughput.

[0086] The vibrating trough 10 is excited by a vibration exciter 20, which is advantageously spatially attached to the trough support 31. The exciter excites the plastic particles in the vibrating trough 10 by subjecting them to helical or vortex-like movement, thereby achieving good mixing of the particles. This, in turn, results in a very uniform temperature distribution among all the particles, meaning that all particles are processed under as similar conditions as possible, thus establishing a very uniform product quality.

[0087] Under vibration excitation conditions, the residence time of plastic granules in the vibrating tank 10 is typically 20 to 60 minutes, during which time the vibrating tank is filled to approximately 50% or more of its cross-section. At the end of the residence time, crystallization has progressed to the point where the granules are no longer sticky, allowing them to be completely filled or to crystallize to a higher degree in other devices.

[0088] The present invention has been explained in detail above with reference to one possible embodiment and other modifications. These embodiments and modifications serve to demonstrate the feasibility of the invention. The independent technical features explained above in the context of other independent features may also be implemented independently of said other independent features and in combination with other independent features, even if not explicitly described, provided that it is technically feasible. Therefore, the present invention is explicitly not limited to the specifically described embodiments, but includes all embodiments as defined by the claims.

Claims

1. A heavy-duty vortex groove device (1), comprising: A vibrating groove (10) for receiving plastic particles has a groove base (11) and two opposing sidewalls (12a, 12b). The length of the vibrating groove (10) in the longitudinal direction (a) is greater than the maximum height and width of the groove cross section perpendicular to the longitudinal direction. At least two vibration exciters (20) are used to generate vibration excitation, the vibration excitation having a transverse component perpendicular to a plane formed by the longitudinal direction (a) and the vertical direction (z); and At least two groove supports (31) are spaced apart from each other in the longitudinal direction (a) of the vibration groove (10), each supporting the groove base (11) and the sidewalls (12a, 12b) from the outside, and also crossing the vibration groove (10) on the side opposite to the groove base (11). In each case, one of the vibration exciters (20) is fastened to at least two of the slot supports (31).

2. The heavy-duty vortex groove device (1) according to claim 1, characterized in that, Each of the groove support members (31) forms a closed loop that radially surrounds the vibration groove (10).

3. The heavy-duty vortex groove device (1) according to claim 2, characterized in that, The vibration groove (10) passes through the groove support (31) substantially vertically, such that the minimum angle formed by the longitudinal direction (a) of the vibration groove (10) and the main extension plane of the groove support (31) is in the range of 75° to 90°. The main extending plane of the groove support (31) is the yz vertical plane.

4. The heavy-duty vortex groove device (1) according to claim 3, characterized in that, The groove support (31) has an integral support plate (34) with a constant wall thickness, and the passage opening (33) of the vibration groove (10) is formed in the integral support plate (34).

5. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The base (11) of the vibrating trough (10) is inclined in the longitudinal direction (a) from the feed end (14) to the outlet end (15).

6. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, There are no obstructions in the cross-section of the vibrating trough (10) between the feed end (14) and the outlet end (15).

7. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, Adjacent groove supports (31) are connected to each other in the longitudinal direction (a) of the vibration groove (10) by at least three longitudinal members (32).

8. The heavy-duty vortex groove device according to any one of claims 1 to 4, characterized in that, The vibration exciter (20) is positioned above the vibration groove (10), in a region above either of the sidewalls, in such a way that the line of action (k) of the vibration excitation force of the vibration exciter (20) extends a distance to the upper edge (12c) of the sidewall (12a) on one side of the vibration exciter, the distance being at most 20% of the width of the vibration groove (10) between the sidewalls (12a, 12b).

9. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The line of action (k) of the vibration excitation force of the vibration exciter (20) intersects the groove base (11) in front of the center of the groove base (11) in the transverse direction of the vibration groove (10).

10. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The groove base (11) has a straight portion in the plane of the groove cross section (bc), and the straight portion is inclined to a horizontal portion in the plane of the groove cross section (bc) away from the vibration exciter (20).

11. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The groove base (11) has at least one bend (11a) extending in the longitudinal direction.

12. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The sidewalls (12a, 12b) of the vibration groove (10) are each joined to the groove base (11) via curved portions (13a, 13b), and the radius of curvature (r) of the curved portion (13a) on one side of the vibration exciter (20) is... a The radius of curvature (r) of the curved portion (13b) on the opposite side is greater than that of the curved portion on the opposite side. b ).

13. The heavy-duty vortex groove device (1) according to claim 12, characterized in that, The radius of curvature (r) of the curved portion (13a) on one side of the vibration exciter (20) a The radius of curvature (r) of the curved portion (13b) on the opposite side b The ratio of ) is greater than 2.

14. The heavy-duty vortex groove device (1) according to claim 12, characterized in that, The radius of curvature (r) of the curved portion (13a) on one side of the vibration exciter (20) a The width ratio between the vibration groove (10) and the sidewalls (12a, 12b) of the vibration groove (10) is less than 0.3 and greater than 0.

1.

15. The heavy-duty vortex groove device (1) according to claim 12, characterized in that, The radius of curvature (r) of the curved portion (13a) on one side of the vibration exciter (20) a It is at least one-quarter of the maximum groove depth (t) of the vibration groove (10).

16. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The vibration excitation of the vibration exciter (20) forms an angle (γ) between the line of action (k) of the force in the vertical plane including the transverse direction and the base of the groove (11) in the range of 25° to 50°.

17. The heavy-duty vortex groove device (1) according to any one of claims 1 to 4, characterized in that, The nominal fill level is greater than 50% of the cross-sectional area (bc) of the groove.

18. The heavy-duty vortex groove device according to any one of claims 1 to 4, characterized in that, The vibration exciter (20) is positioned above the vibration groove (10) in a region near the lateral outer side of either of the sidewalls, in such a manner that the line of action (k) of the vibration excitation force of the vibration exciter (20) extends a distance to the upper edge (12c) of the sidewall (12a) on one side of the vibration exciter, the distance being at most 20% of the width of the vibration groove (10) between the sidewalls (12a, 12b).

19. A method for crystallizing plastic particles that tend to agglomerate, characterized in that, The heavy-duty vortex tank device (1) according to any one of claims 1 to 4 is loaded with plastic particles in the vibrating tank (10), the plastic particles having a temperature above their glass transition temperature range when fed, and The vibration exciter (20) excites the vibration groove (10) in such a way that the plastic particles in the vibration groove (10) undergo helical movement. The residence time of the plastic particles in the vibrating trough is 20 to 60 minutes, and the vibrating trough (10) is filled with plastic particles in at least 50% of its cross-section.

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