Die plate assembly for a granulator, and granulator equipped with said die plate assembly

Abstract

The die plate assembly has at least one inlet located on the melt inlet side for introducing the melt and multiple outlets located on the melt discharge side for discharging the melt. The die plate assembly further has a melt transport region having at least one, and preferably multiple, melt flow paths extending from the melt inlet side to the melt discharge side. In the die plate assembly, the melt transport region is separable from the die plate assembly and is designed as a melt transport section that is reversibly attachable to and detachable from the die plate assembly.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This patent application claims the benefit of German Patent Application No. 102023100777.7, filed January 13, 2023, the entire text of which is incorporated herein by reference.

[0002] The present invention relates to a die plate assembly for a pelletizing apparatus for producing granules from a liquid resin melt, particularly a thermoplastic material, the die plate assembly comprising: at least one inlet located on a melt inlet side for introducing the melt; multiple outlets located on a melt discharge side for discharging the melt; and a melt transport region having at least one, and preferably multiple, melt flow paths extending from the melt inlet side to the melt discharge side. The present invention also relates to a melt transport section for transporting the melt, a pelletizing apparatus for producing granules from the melt, and a method for repairing a pelletizing apparatus having a die plate assembly. [Background technology]

[0003] Such die plate assemblies are known in the prior art and are used, for example, in granulators. They are primarily used to extrude a liquid resin melt, such as a thermoplastic resin melt, into multiple molten strands through a melt transport zone. In underwater granulation, the individual molten strands pass through the melt transport zone and are then separated into strand pieces by a cutting device. A cooling medium, such as water, flows along the discharge side of the die plate assembly, and the molten strands exiting the discharge side come into contact with the cooling medium, cooling the separated strand pieces that become granules. Underwater granulation allows for the highly efficient production of resin granules from a liquid resin melt.

[0004] In die plate assemblies known from the prior art, a liquid resin melt is supplied from an inlet to the die plate body, particularly to its melt transport region. A channel, preferably a plurality of channels, provided in the melt transport region of the die plate body divides the liquid resin melt into molten strands, the number of which corresponds to the number of channels present in the melt transport region. On the melt discharge side, the die plate body is provided with a plurality of outlets for discharging the melt, the size of which can be changed depending on the type of resin melt to be processed. Due to the large number of outlets, die plate assemblies known from the prior art exhibit high productivity in producing resin granules with relatively small particle sizes.

[0005] In the production of resin granules, die plate assemblies are subject to continuous wear due to the relatively high pressures encountered during granule production and the cutting equipment that moves continuously along the melt discharge side. Reconditioning such die plate assemblies at least once can extend their useful life. However, die plate assemblies known from the prior art can only be reconditioned a limited number of times. After a certain number of reconditionings or operating hours, the primarily one-piece die plate assemblies eventually wear out and require replacement. The melt transport region is typically secured by a middle portion that contacts the inside of the melt transport region and a peripheral portion that contacts the outside of the melt transport region. The adjacent peripheral and middle portions provide the die plate assemblies known from the prior art with high structural strength.

[0006] Therefore, periodic replacement of the die plate assemblies entails correspondingly high material and labor costs, essentially making the manufacture of such die plate assemblies very costly. Even if the die plate assemblies known from the prior art can be reused multiple times, the known die plate assemblies have diameters of 200 to 800 mm and weigh more than 100 kg, making them difficult to handle, and such a re-use process still requires a considerable amount of labor.

[0007] In light of this background, the object of the present invention is to provide a die plate assembly for a granulator, a granulator for producing granules, and a method for repairing a granulator, which eliminate as far as possible the drawbacks identified in the prior art. In particular, a die plate assembly, a granulator, and a method for repairing a granulator are specified that can be manufactured simply and at low cost and are easy to handle when repairing the die plate assembly. Summary of the Invention

[0008] According to the present invention, this object is achieved in a die plate assembly of the initially defined type by means of an arrangement having the features of claim 1. In particular, the melt transport region is designed as a melt transport section that is separable from the die plate assembly and that is reversibly attachable to and detachable from the die plate assembly.

[0009] The approach taken in the present invention is to provide a melt transport region, which is subject to continuous wear during extrusion of a resin melt, as a separate part of the die plate assembly, particularly the die plate body, rather than using an integrated die plate assembly. The melt transport section of such a die plate assembly is reversibly detachable from the die plate assembly. If necessary, the melt transport section can be replaced and reused on the die plate assembly of the present invention after a simplified reconditioning process, or replaced with a completely new melt transport section.

[0010] Therefore, the manufacture of such a die plate assembly significantly reduces material and cost consumption, and such a die plate assembly of the present invention can simplify repair and maintenance of the granulation apparatus. Therefore, the die plate assembly, or the die plate body of the die plate assembly, has a replaceable melt transport portion that forms in the die plate assembly a melt inlet side for introducing a liquid resin melt, a melt discharge side having a plurality of outlets for discharging the melt in the form of molten strands, and a flow path extending from the melt inlet side toward the melt discharge side.

[0011] According to a preferred embodiment of the die plate assembly of the present invention, the die plate assembly is formed by at least a melt transport section and an intermediate section and / or an outer ring, with the melt transport section being detachably coupled to the intermediate section and / or the outer ring. In addition to the melt transport section, the die plate assembly has at least an outer ring that contacts the outside of the melt transport region and / or an intermediate section that contacts the inside of the melt transport section. The outer ring that contacts the outside of the melt transport section is preferably used to mount the die plate assembly to a die plate holder, particularly a start-up valve, associated with a pelletizing apparatus. A compact die plate assembly can also be mounted to the pelletizing apparatus itself. The intermediate section that contacts the inside of the melt transport section is particularly used to distribute the liquid resin melt flowing toward the melt inlet side of the die plate assembly to a generally annular inlet region of the die plate assembly. The inlet region particularly extends in a generally circular shape around the central axis of the die plate body.

[0012] The melt transport section is preferably generally annular, and the flow channels are preferably spaced apart on at least one circle. The annular design of the melt transport section provides a particularly structurally simple design, and the circular arrangement of the flow channels allows for a relatively high material throughput in a melt transport section configured according to the present invention.

[0013] According to one embodiment of the die plate assembly of the present invention, a plurality of outlets corresponding to each flow path may be formed on circles of different sizes on the melt transporting section, and such a melt transporting section of the present invention may have a plurality of rows of flow path outlets spaced apart from each other in the radial direction.

[0014] According to a preferred embodiment of the present invention, the outer ring of the die plate assembly has a receiving portion for positioning the melt transport portion relative to the outer ring. The receiving portion securely fixes the melt transport portion to the outer ring of the die plate assembly and holds the outer ring and the melt transport portion relative to each other in the flow direction of the liquid resin melt. In the simplest embodiment, the receiving portion of the outer ring is provided with one or more holding areas that are contactable with the melt transport portion and prevent relative movement of the outer ring and the melt transport portion in a direction parallel to the flow path in the melt transport portion or in a radial direction.

[0015] In a preferred embodiment, the accommodation for the melt transport section is accessible from the melt inlet side or the melt discharge side. The advantage of providing the accommodation for the melt transport section on the outer ring and on the melt inlet side of the die plate assembly is that pressure acting in the direction of resin melt flow is safely absorbed by the outer ring that holds the melt transport section and dispersed to a structure that strengthens the die plate assembly. On the other hand, the advantage of providing the accommodation section on the melt discharge side is that the melt transport section formed separately from the outer ring according to the present invention can be removed from the die plate assembly while the die plate assembly of the present invention remains attached to the granulator, further improving handling, particularly during repair of such a die plate assembly of the present invention.

[0016] According to one embodiment, the outer ring has a recess, preferably a stepped recess, with a stop surface extending substantially radially for receiving the melt transport portion, to form the receiving portion. Preferably, the outer ring has a central recess into which the melt transport portion can be inserted, the outer ring having at least one stop surface protruding radially in the insertion direction of the melt transport portion, and the separately formed melt transport portion contacts this stop surface when inserted into the outer ring. The outer ring is provided with a stepped recess, preferably circumferential, as the receiving portion. In another embodiment, the outer ring is provided with stepped recesses that are spatially discontinuous in the circumferential direction.

[0017] To obtain a form-fit connection between the outer ring and the melt transport portion that acts in the flow direction, the melt transport portion is formed with at least one preferably circumferential protrusion that protrudes radially outward and has an abutment surface that corresponds to a stop surface on the outer ring. The recess on the outer ring and the protrusion on the melt transport portion fit together conformally and provide a locking function when the melt transport portion is inserted into the outer ring along the longitudinal direction of the flow path. In a preferred embodiment, the recess on the outer ring and the protrusion on the melt transport portion are designed so that the outer ring and the melt transport portion are locked together in the circumferential direction.

[0018] According to another embodiment, the outer ring has a receiving surface that conically narrows from the melt inlet side toward the melt outlet side to form a receiving section. The outer ring has a receiving cone that forms the receiving section, so that when a separately formed melt transport section is inserted, the contacting surfaces of the outer ring and the melt transport section converge. In addition to the form-fit connection achieved by the gradually decreasing diameter of the receiving cone, the components of the die plate assembly are radially centered relative to one another between the converging surfaces. The outer ring of the die plate assembly also has a self-locking mechanism for locking the melt transport section.

[0019] Preferably, the melt transport section has a conically tapered diameter from the melt inlet side toward the melt outlet side and an abutment surface defining a portion of its outer periphery, the abutment surface corresponding to the receiving surface of the outer ring. In addition to the longitudinal locking effect of the flow passage, a sealing effect is achieved between the receiving cone of the outer ring and the conically tapering outer periphery. The conically tapering surfaces of the outer ring and the melt transport section are preferably formed only along portions that run parallel to the longitudinal axes of the outer ring and the melt transport section, respectively. In addition to the axial locking effect between the melt transport section and the outer ring, the melt transport section is aligned radially inward of the receiving portion of the outer ring.

[0020] In another alternative or substitutive embodiment of the die plate assembly of the present invention, the receiving portion of the outer ring is designed as a rotary plug connection having at least one groove-like recess extending in the circumferential direction and an axially open insertion area for inserting the fastening portion of the melt transport portion into the recess. The rotary plug connection advantageously positions the melt transport portion circumferentially relative to the outer ring in addition to axially positioning the outer ring and the melt transport portion relative to each other. A groove-like recess, preferably extending over a limited circumferential range, forms a stop surface for the fastening portion inserted therein. The rotational direction of the rotary plug connection along the circumferential direction, and the resulting stop function, preferably corresponds to or is identical to the rotational direction of the cutting head cooperating with the die plate assembly.

[0021] Preferably, the melt transport section has at least one protrusion axially spaced from the melt inlet side and the melt discharge side of the melt transport section, protruding radially from the outer periphery and extending along a portion of the circumferential direction to form a stop. A multi-component die plate body having such a rotary plug connection can be used to form a receiving section, particularly accessible from the melt discharge side. The matching mating material areas of the melt transport section and the outer ring form a secure structural connection between the reversibly detachable parts of the die plate assembly, particularly one that can withstand pressures generated during the production of resin granules. Preferably, multiple such protrusions are arranged along the outer periphery of the melt transport section. To ensure the necessary strength of the die plate assembly of the present invention, the protrusions have a thickness parallel to the longitudinal direction of the flow channel that corresponds to approximately one-third to one-half of the total thickness of the die plate body from the melt inlet side to the melt discharge side.

[0022] In another preferred embodiment of the die plate assembly of the present invention, matching mating elements are formed on the insert region and the corresponding protrusion, respectively, as positioning means, thereby defining a preferred orientation when assembling the melt transport section and the outer ring. The mating elements provided on only one insert region and one protrusion can prevent incorrect assembly of the melt transport section and the outer ring relative to each other. In a preferred embodiment, when a heating tube is provided extending radially from the outside through the outer ring to the melt transport section, correct assembly of the die plate assembly components ensures fluid flow through the melt transport section.

[0023] According to another preferred embodiment of the die plate assembly of the present invention, the outer ring and the melt transport section are provided with corresponding recesses that are axially aligned with each other during operation and are arranged to secure the outer ring and the melt transport section to each other. The recesses in the outer ring and / or the melt transport section, some of which are preferably threaded, provide a firm and secure connection between the two components joined in the die plate assembly of the present invention. The fastening means housed in the recesses in the outer ring and the melt transport section can be loosened to allow the components to be separated again. Preferably, a detachable connection is formed between the melt transport section and the outer ring so that the melt transport section can be reversibly attached to and detached from the die plate assembly of the present invention. Depending on the configuration of the recesses in the melt transport section and / or the outer ring, these recesses may be provided with threads. In this case, the diameter of the axially adjacent recesses in the respective components is set to be larger than the outer diameter of the fastening means inserted therein to ensure a clamping effect between the connected components.

[0024] According to another preferred embodiment of the die plate assembly of the present invention, the melt transport section and / or the outer ring have at least one heating channel for transporting a heat transfer medium or a heating conductor receptacle for inserting an electric heating conductor, positioned radially inward and / or outward relative to the melt flow path. The at least one heating channel, preferably adjacent to the flow path in the melt transport section, heats the die plate assembly and maintains the liquid resin melt at a desired temperature, thereby maintaining a flowable state during normal operation. By combining this with the embodiments described below (such as an air gap or forming the melt transport section from a material with a different thermal conductivity from that of the outer ring and / or the middle section), heat transfer to the outer ring and the middle section can be further reduced so that sufficient heat input is achieved only through the melt transport section during normal operation. The multi-component structure of the die plate assembly can reduce energy consumption during operation of the granulation device. In a preferred embodiment of the present invention, the outer ring is provided with one or more heating channels for rapid heating of the die plate assembly upon startup of the granulation process, and these heating channels are preferably supplied with a fluid gas or liquid heat transfer medium. Alternatively, an electrical heating conductor may be placed within the heating channel of the outer ring. Heater strips may also be wrapped around the outer ring during start-up.

[0025] Preferably, the heating channel in the melt transport section extends along a portion of the flow path, and the heating channel is located on the outlet end side of the flow path. The heating channel adjacent to the flow path in the melt transport section allows efficient heat input to the adjacently arranged flow path and the resin melt flowing through the flow path. The heating channel or a portion of a single heating channel is preferably positioned radially inward and radially outward relative to the flow path. This further improves heat input to the flow path in the separately formed melt transport section.

[0026] According to a preferred embodiment of the die plate assembly, the heating channel is an annular space, and the melt transport section has at least one inlet for a heat transfer medium to enter the heating channel and at least one outlet for the heat transfer medium to exit the heating channel. The heating channel or a portion thereof preferably extends as an annular space along a flow path arranged circularly on the melt transport section. Such annular spaces through which a heat transfer medium flows to heat the melt transport section are preferably formed both inside and outside the flow path.

[0027] To improve heat transfer to the resin melt passing through the flow path, the inner and outer heating channels are fluidly connected to each other, preferably via connecting channels extending radially. In one embodiment, the heating channels have a radially extending inlet and, in particular, at least one radially extending outlet, which are formed in opposite regions across the melt transport section. In a preferred embodiment, the heating channels have two outlets for discharging the heat transfer medium, which are located approximately opposite the inlet at the periphery of the melt transport section and are arranged at an angle of approximately 35° to 55° from each other.

[0028] According to the present invention, the melt transport section has at least one base member surrounding the flow path and at least one separately constructed, substantially cylindrical sleeve member, which defines the boundary of at least one inner and / or outer wall region of the melt transport section and preferably defines the outer wall of the heating channel facing away from the flow path. The sleeve member, which is arranged separately from the base member having the flow path, particularly defines the outer wall region of the heating channel and simultaneously defines the inner and / or outer wall region of the melt transport section. The above-mentioned dual-function sleeve members are preferably arranged inside and outside the base member. These sleeve members have different diameters.

[0029] Preferably, each sleeve element is hermetically or materially connected to the melt transport element, particularly to the adjacent region of its base element. This serves as a seal between the contact surfaces of the sleeve element and the base element of the melt transport element, ensuring the heat transfer medium is retained within the heating channel spatially bounded by the sleeve element. A welded connection is preferred as the materially connected sleeve element to the melt transport element. Alternatively, the sealing function can be achieved by, for example, pressing a sealing element arranged on the base element of the melt transport element with the corresponding contact surface of the sleeve element, thereby achieving a sealing effect between the connected components.

[0030] According to a preferred embodiment of the present invention, the melt transport section is divided into at least two separate segments, preferably ring segments. Instead of a single annular member, the melt transport section can be divided into two, three, or more segments. This has the advantage that, if necessary, only a portion of the melt transport section of the die plate assembly of the present invention needs to be replaced rather than the entire melt transport section, for example, if one segment of the melt transport section suddenly becomes defective, necessitating early replacement of that portion. The two, three, or more segments are arranged relative to each other on the outer ring of the die plate assembly, like pieces of a cake, with their end faces in contact with each other and preferably sealed to prevent the flowing resin melt from penetrating between the end faces of adjacent segments of the melt transport section. Alternatively, the melt transport section can be designed as a single segment with a radially extending separating slit, like a Zager circlip ring.

[0031] In a preferred embodiment of the die plate assembly of the present invention, each segment has at least one connection port as an inlet to the heating channel and at least one further connection port as an outlet from the heating channel, and preferably a radially extending recess is provided in the outer ring on the melt inlet side. Each segment of the melt transport section has at least one inlet as an inlet point for the heat transfer medium and at least one outlet as an outlet point for the heat transfer medium to ensure the necessary heat input in its flow path region. These connection ports are preferably located at opposite ends of the segment, thereby allowing efficient transfer of thermal energy contained in the heat transfer medium to the melt transport section and the resin melt flowing through the melt transport section.

[0032] Preferably, instead of purely radially extending through-holes, radially extending recesses accessible from the melt inlet side are provided in the outer ring for inserting the heating pipes for the heat transfer medium connected to the segments, so that the segments with pre-assembled heating pipes can be easily inserted from the melt inlet side into the designated sections provided in the outer ring.

[0033] Preferably, the melt transport section has a receiving portion for holding the intermediate section in the melt transport section, and the intermediate section is preferably composed of a plurality of individual parts. The receiving portion of the melt transport section allows the intermediate section to be securely positioned and securely connected to the melt transport section formed separately from the intermediate section. In one possible embodiment of the die plate assembly, a cylindrical receiving portion for the intermediate section is preferably provided inside the melt transport section.

[0034] According to a preferred embodiment of the present invention, the receiving portion for the intermediate portion is accessible from the melt discharge side and has at least one stepped recess with a radially extending receiving surface for the intermediate portion. The stepped recess and its substantially radially extending circumferential receiving surface provide a receiving portion for the intermediate portion in the melt transport portion that is structurally simple to manufacture and achieves a perfect fit. The intermediate portion is preferably inserted into the receiving portion provided in the melt transport portion from the melt discharge side. This facilitates the attachment and detachment of the die plate assembly of the present invention to and from the granulation apparatus.

[0035] Preferably, the intermediate portion has a radially outwardly protruding, preferably circumferentially shaped, protruding portion having an abutment surface corresponding to the receiving surface of the melt transport portion. The intermediate portion having the radially protruding protrusion on its outer periphery is particularly designed to abut in a shape that matches the receiving surface of the melt transport portion. As a result, when the intermediate portion comes into contact with the melt transport portion, the intermediate portion is automatically positioned relative to the melt transport portion. The intermediate portion is particularly positioned in the axial direction of the die plate assembly.

[0036] According to one embodiment of the die plate assembly of the present invention, the intermediate section comprises a substantially cylindrical base member and a guide cone connectable to the base member, the intermediate section having at least one alignment element for positioning the guide cone on the base member. The base member and guide cone constituting the intermediate section are positioned to contact a portion of the melt transport section from opposite sides of the die plate body (the melt inlet side and the melt outlet side). The components of the intermediate section that engage in this manner are connected to each other and create a clamping effect on the portion of the melt transport section sandwiched therebetween. Preferably, the guide cone is fixed to the base member using the alignment element so that the longitudinal axes of the base member and the guide cone coincide with each other.

[0037] In one embodiment of the die plate assembly, a preferably circumferential air gap is formed at least partially between the outer ring and the melt transport section and / or between the melt transport section and the intermediate section. The air gap, which preferably extends along a portion of the axial direction between the surfaces of the outer ring, the melt transport section, and the intermediate section, which would otherwise be in contact, can improve the thermal insulation of the parts being joined. This is sufficient in this embodiment, and heat transfer to the components of the die plate assembly connected to the melt transport section is minimized, so that only the melt transport section receives thermal energy to maintain the melt in a liquid state through the heating path formed therein. To form the air gap, recesses or depressions may be partially formed in the inner and outer walls of the melt transport section or in the walls of the outer ring and the intermediate section facing the melt transport section.

[0038] According to a possible development of the die plate assembly, the outer ring and / or the intermediate section, as well as preferably the sleeve member, are made of a material with a lower thermal conductivity than the material forming the melt transport section. In certain embodiments of the die plate assembly of the present invention, the use of materials with different thermal conductivities can minimize heat transfer around the melt transport section of the die plate assembly and further improve the thermal insulation effect. The intermediate section and the outer ring, as well as portions of the sleeve member that form part of the inner and outer walls of the melt transport section, are preferably made of a material that has thermal insulation properties compared to the melt transport section, which is preferably made of a metallic material. This reduces the heat input and, therefore, the amount of energy required to maintain the resin melt in a fluid state as it passes through the die plate assembly of the present invention. Therefore, embodiments of the die plate assembly of the present invention help to reduce the amount of energy required to produce granules.

[0039] According to another embodiment, the melt transport portion is manufactured by additive manufacturing, particularly three-dimensional printing. Additive manufacturing allows the melt transport portion to be designed as a one-piece molded part, preferably including all structural features, including shoulders, undercuts, flow channels extending from the melt inlet side to the melt outlet side, and annular heating channels disposed adjacent to the flow channels, during the manufacture of the component. The melt transport portion can be manufactured without the need for post-processing, but is not limited to this. Alternatively, the melt transport portion can be manufactured using a casting process. Additive manufacturing can be used to manufacture one-piece molded parts, particularly those with a small distance between the heating channel and the melt channel within the component, and with closed cavities, which improves structural stability compared to components made of individual components and minimizes weight for easier handling.

[0040] A further aspect of the present invention relates to a melt transport section for transporting a melt, particularly a melt of a thermoplastic material, for a die plate assembly of a granulator, particularly for at least one of the die plate assemblies of the above-mentioned preferred embodiments. The melt transport section of the present invention has a melt inlet side and a melt outlet side and a plurality of flow passages extending from the melt inlet side to the melt outlet side, and similarly achieves the objectives of the die plate assembly by being designed as a separate part provided with an abutment surface for an outer ring reversibly contactable with the outside of the melt transport section and / or for an intermediate part of the die plate assembly reversibly contactable with the inside of the melt transport section.

[0041] The separately configured melt transport section according to the present invention allows for a multi-component structure of the die plate assembly including the melt transport section, which is advantageous for later assembly and disassembly of the die plate assembly in a pelletizing apparatus when repairs are required. Therefore, instead of disassembling and replacing the entire die plate assembly from the pelletizing apparatus, it is possible to simply disassemble a portion of the die plate assembly (the melt transport section and the intermediate section of the die plate assembly connected to it) while leaving the outer ring attached to the pelletizing apparatus. Furthermore, the refurbishment or replacement of the melt transport section on the die plate assembly of the present invention is simplified, resulting in significant reductions in material and cost consumption. The outer ring and intermediate section of the die plate body of the present invention can be used in combination with a refurbished or new melt transport section. The preferred outer and inner abutment surfaces of the melt transport section allow for particularly simple and reversible contact and separation of the melt transport section with the outer ring of the die plate assembly and / or the intermediate section of the die plate assembly. Preferably, an air gap is provided partially in the outer ring and / or the intermediate section that contact the melt transport section, thereby improving the thermal insulation of the melt transport section from the outer ring and / or the intermediate section. This means that the heat input from the heat transfer medium that maintains the melt passing through the melt transport section in a liquid state is preferably limited to the area of ​​the melt transport section. For this purpose, recesses or depressions may be partially formed in the inner and outer walls of the melt transport section or in the walls of the outer ring and the intermediate section that face the melt transport section.

[0042] Such a melt transport section for the die plate assembly of the invention has the same advantages and preferred developments as the die plate assembly of the invention, and vice versa.

[0043] A third aspect of the present invention relates to a granulation apparatus for producing granules from a melt, particularly a thermoplastic material, comprising a die plate assembly for transporting a melt. The granulation apparatus is characterized in that the die plate assembly is a die plate assembly according to any of the above-mentioned preferred embodiments. The present invention utilizes the discovery that melt transport regions known from the prior art can be configured as separate components configured separately from the die plate assembly. According to this third aspect, the die plate assembly comprises a multi-component die plate body comprising at least an outer ring, a separate melt transport section, and a similarly separate middle section, which can be reversibly separated from one another and reassembled to form the die plate body.

[0044] In yet another aspect, the present invention relates to a method for repairing a granulation apparatus having a die plate assembly, particularly a granulation apparatus according to the preferred embodiment described above, comprising the steps of at least partially disassembling the die plate assembly, replacing a melt transport section or segment of the die plate assembly, and mounting the section of the die plate assembly with the new melt transport section or segment attached to a die plate holder or the granulation apparatus, wherein the section of the die plate assembly is disassembled and mounted from the melt discharge side.

[0045] The method steps of the present invention allow for easier repair of granulators equipped with the die plate assembly of the present invention. Repairing the die plate assembly preferably requires only partial disassembly, replacing defective or used segments or the entire melt transport section, and then simply installing new components on the die plate assembly, which remains at least partially attached, for example, to the die plate holder and the granulator. In one variation of the method of the present invention, the entire die plate assembly is disassembled from the die plate holder, and then the melt transport section, or a portion thereof, is disassembled and replaced from the removed die plate assembly. Replacement of the melt transport section is preferably performed from the melt inlet side when the die plate assembly is completely disassembled.

[0046] The preferred embodiments and developments described with respect to the die plate assembly or the melt transport section are also preferred embodiments of the granulation apparatus and the method for replacing a granulation apparatus comprising a die plate assembly of the present invention. The preferred embodiments and developments of the granulation apparatus and the method described herein that relate to the die plate assembly or the melt transport section are also preferred embodiments of the die plate assembly or the melt transport section itself.

[0047] Certain aspects of the present disclosure have thus been outlined in order that the detailed description herein may be understood, and that the present invention may be better appreciated as a contribution to the art. There are, of course, additional aspects of the disclosure that will be described hereinafter and which will form the subject matter of the appended claims.

[0048] In this regard, before explaining at least one aspect of the present disclosure in detail, it is to be understood that the disclosure is not limited to the details of construction and the arrangement of parts set forth in the following description or set forth in the drawings. The disclosure is capable of being practiced and carried out in various ways in addition to those described. Moreover, the phraseology and terminology used herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.

[0049] As such, those skilled in the art will appreciate that the conception underlying this disclosure may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the purposes of the present disclosure, and the appended claims should accordingly be construed to include such equivalent structures insofar as they do not depart from the spirit and scope of the present disclosure.

[0050] Further features and advantages of the invention will become apparent from the following detailed description of the preferred embodiments, which are illustrated with reference to the accompanying drawings. [Brief explanation of the drawings]

[0051] [Figure 1]FIG. 1 is a perspective view showing one embodiment of a granulation apparatus equipped with a die plate assembly of the present invention. [Figure 2] FIG. 1 is a perspective view of a first embodiment of a die plate assembly of the present invention with a heating tube connected thereto. [Figure 3] 2 is a perspective view of the first embodiment of the melt transport section of the present invention shown in FIG. 1. FIG. [Figure 4] FIG. 2 is a partial cross-sectional view of the die plate assembly of the present invention shown in FIG. [Figure 5] FIG. 10 is a partial cross-sectional view of another embodiment of the die plate assembly of the present invention. [Figure 6] FIG. 10 is a partial cross-sectional view of another possible embodiment of the die plate assembly. [Figure 7] 7 illustrates a portion of one embodiment of the melt transport section of the die plate assembly shown in FIG. 6. [Figure 8] FIG. 10 shows another embodiment of the die plate assembly of the present invention with a heating tube connected thereto. [Figure 9] FIG. 9 is a partial cross-sectional view of the die plate assembly of the present invention shown in FIG. 8. [Figure 10] FIG. 10 is a perspective view of the embodiment of the melt transport portion shown in FIGS. 8 and 9. [Figure 11] FIG. 10 is a perspective view of another embodiment of the die plate assembly of the present invention. [Figure 12] FIG. 12 is an exploded perspective view of the melt transport portion of the die plate assembly of the present invention shown in FIG. 11. [Figure 13] FIG. 10 is a perspective view from the melt entry side of another embodiment of the die plate assembly of the present invention having a melt transport portion according to one embodiment. [Figure 14] FIG. 10 is a perspective view from the melt discharge side of another embodiment of a die plate assembly of the present invention having a melt transport portion according to one embodiment. [Figure 15] 1 is a schematic cross-sectional view showing the structure of one embodiment of a molten material transport section of the present invention. [Figure 16] 1 is a schematic cross-sectional view showing the structure of one embodiment of a molten material transport section of the present invention. [Figure 17] 1 is a schematic block diagram of a method for repairing a granulation device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0052] 1 shows a pelletizing apparatus 100 designed herein and preferably configured as an underwater pelletizer. The inventive embodiments of the die plate assemblies 1, 1' described below are of course also applicable to other pelletizing apparatuses. The pelletizing apparatus 100 comprises an underwater pelletizer 102 driven by a drive means 104. The pelletizing apparatus is also provided with a protective cover 106.

[0053] The pelletizing apparatus 100 is associated with an underwater pelletizer 102 and further includes a die plate assembly 1 to which a liquid resin melt is typically supplied from an extruder (not shown). The die plate assembly 1 is attached to a die plate holder (not shown), for example, by a plurality of fixing screws 108, and is heated via an inlet and an outlet 56 that function as connection ports for a heat medium supplied via a heating tube 112 (see FIG. 2) in the die plate assembly 1.

[0054] The underwater pelletizer 102 has a process water inlet 114 and a process water outlet 116, through which process water is supplied to and discharged from the melt discharge side 6 of the die plate assembly 1 of the present invention. During operation of the pelletizer 100, a resin melt flows into the die plate assembly 1 shown in FIG. 1 from the melt inlet side 4 of the die plate body 2, is split into multiple resin strands inside the die plate body 2, and flows out as continuously flowing molten strands at the melt discharge side 6 (FIG. 4). The underwater pelletizer 102 further includes a cutting device (not shown) that moves along the melt discharge side of the die plate body 2 and continuously splits the discharged molten strand into individual strand pieces.

[0055] In one embodiment, the cutting device of the underwater pelletizer 102 includes a rotary cutting head (not shown) with a plurality of cutting blades arranged thereon. In the underwater pelletizer 102, the exiting molten strands / separated strand pieces are cooled by contact with process water, and the separated strand pieces are discharged from the underwater pelletizer via the process water outlet 116 and separated from the process water in a separation process step.

[0056] The drive means 104 is used to drive the cutting device (not shown), and in particular to impart rotational movement to the cutting device and its cutting blades. The assembly including at least the underwater pelletizer 102 and the drive means 104 is mounted via spacer elements 120 to a machine bed 118 arranged in a movable housing structure 122.

[0057] 2 shows a possible embodiment of the die plate assembly 1 shown in FIG. 1 in a state separated from the granulation apparatus 100. The die plate assembly 1 includes a die plate body 2 having a melt inlet side 4 and a melt discharge side 6 located opposite the melt inlet side 4. The melt inlet side 4 is provided with at least one inlet 8 for supplying the melt to the die plate assembly 1. The melt discharge side 6 is provided with a plurality of discharge ports 10 (see FIG. 4) for discharging the melt.

[0058] The die plate assembly 1 also has a melt transport region 12, and in this embodiment, this region is formed with a plurality of flow paths 14 for the resin melt, extending from the melt inlet side 4 toward the melt outlet side 6. The die plate body 2 has an outlet 10 disposed at the end of each flow path 14, and the resin melt is discharged from the die plate body 2 as a plurality of molten strands, which are supplied to an underwater granulator 102 and split into strand pieces.

[0059] According to the present invention, the melt transport region 12 is designed as a melt transport section 16 that is separable from the die plate assembly 1, in particular from the die plate body 2. The melt transport section 16 is therefore reversibly attachable to and detachable from the die plate body 2. In addition to the melt transport section 16, the die plate assembly 1 further comprises an outer ring 18 and an intermediate section 20. The die plate body 2 is therefore of a multi-component construction.

[0060] The die plate assembly 1 is connected to a die plate holder (not shown) via an outer ring 18. For that purpose, the outer ring 18 is provided with a number of screw holders 22 for the fixing screws 108 shown in Figure 1. The inlets and outlets 56 of the heating tubes 112 formed as connection ports in the die plate assembly 1 can also be seen. The resin melt is fed via an intermediate section 20 to a circular inlet 8 at the melt inlet side 4 of the die plate assembly 1.

[0061] 3 shows a generally annular melt transport section 16 separated from the die plate assembly 1. In the melt transport section 16, channels 14 can also be seen adjacent to the circular inlet 8 on the melt inlet side 4. In this embodiment, the channels 14 are arranged side by side in an annular shape.

[0062] 4, it can be seen that the outer ring 18 has a receptacle 24 for the melt transport section 16 that is surrounded on the outside by the outer ring 18. The receptacle 24 positions the melt transport section 16 radially and longitudinally relative to the central axis L of the die plate assembly 1. In the embodiment shown in FIG. 4, the receptacle 24 for the melt transport section 16 is accessible from the melt inlet side 4.

[0063] 5 , the receiving portion 24′ of the outer ring 18′ is accessible from the melt discharge side 6. Thus, the melt transport portion 16′ is inserted into the receiving portion 24′ from the melt discharge side 6. The receiving portion 24′ is similarly designed to position the melt transport portion 16 radially and longitudinally relative to the central axis L of the die plate assembly 1.

[0064] In FIG. 5, the outer ring 18′ and the melt transport section 16′ are further provided with corresponding recesses 26, 26′ in the form of drilled holes, which are aligned with each other when the die plate assembly 1 is in an assembled state and are configured to secure the outer ring 18′ and the melt transport section 16′ to each other by means of fastening means 27.

[0065] In the embodiment of the die plate assembly 1 shown in FIGS. 4 and 5, the outer ring 18, 18' has stepped recesses 28, 28' that define the receiving portions 24, 24'. Each recess 28, 28' has a radially extending stop surface 30, 30' that contacts and axially positions the melt transport portion 16, 16' when inserted into the outer ring 18, 18'. To achieve this stop function, the melt transport portion 16, 16' shown in FIGS. 4 and 5 has at least one radially outwardly projecting protrusion 32, 32', preferably a circumferential protrusion in this case. When the separately constructed melt transport portion 16, 16' is installed, the protrusion 32, 32' abuts at its abutment surface 34, 34' against the corresponding stop surface 30, 30' of the outer ring 18, 18'.

[0066] The intermediate section 20 of the die plate assembly 1 shown in FIGS. 4 and 5 includes a base member 36 and a guide cone 38 connectable to the base member 36. The guide cone 38 guides the melt flowing toward the die plate assembly 1 to the inlet 8 of the die plate body 2 formed in the melt transport section 16, 16'. The melt transport sections 16, 16' shown in FIGS. 4 and 5 each include a receiving section 40 for holding the intermediate section 20 in the melt transport section 16, 16'. Each receiving section 40 for the intermediate section 20 is accessible from the melt discharge side 6. The receiving section 40 preferably has a stepped recess 42 for the intermediate section 20, which preferably has a receiving surface 44 extending radially. The intermediate section 20, particularly the base member 36, preferably has a protrusion 46 protruding radially outward, which has an abutment surface 48 corresponding to the receiving surface 44 of the melt transport section 16, 16'.

[0067] 5, the base member 36 has alignment elements 50 for securing the guide cone 38. The guide cone 38 is secured to the base member 36 by a plurality of fastening means 52, such as screws, thereby securing the portion of the melt transport section 16'' inserted therebetween.

[0068] 4 and 5, at least one heating path 54 for transporting a heat medium is provided in the melt transport sections 16, 16', which is disposed radially inward and radially outwardly offset with respect to the melt flow path 14. The heat medium selectively introduces thermal energy to the outlet region of the flow path 14 via the heating path 54, thereby maintaining the resin melt in a flowable state within the multiple discharge ports 10 with reduced cross-sections of the melt transport sections 16, 16' of the die plate assembly 1.

[0069] In the embodiments shown in Figures 4 and 5, a preferably circumferential air gap 25 is provided at least partially between the outer ring 18, 18' and the melt transport section 16, 16', and between the melt transport section 16, 16' and the intermediate section 20. For this purpose, in Figure 4, a material recess 25' is partially formed in the inner wall region 94 of the melt transport section 16 or in the wall 95 of the outer ring 18 facing the melt transport section 16. Meanwhile, in Figure 5, a material recess is partially introduced in the inner and outer wall regions 94, 94' of the melt transport section 16'.

[0070] In this embodiment, the flow channel 14 is connected to a number of (in this case four) outlets 10 with a greatly reduced cross section, through which the molten strand is discharged from the melt discharge side 6 .

[0071] The outer rings 18, 18' and melt transport sections 16, 16' have inlets and outlets 56, 56' configured as connection ports for introducing and discharging the heat transfer medium into and from the heating passage 54. Each of the inlets and outlets 56, 56' is connected to at least one heating tube 112.

[0072] 6 and 7 show another embodiment of the die plate assembly 1 of the present invention. In this die plate assembly 1, instead of the stepped recess shown in the previous figures, the outer ring 18'' is provided with a receiving portion 58 having a conically tapered diameter from the melt inlet side 4 to the melt outlet side 6. The conical receiving surface 58 extends over a portion of the total depth TG of the outer ring 18''. In this embodiment, the melt transport portion 16'' is insertable into the outer ring 18'' from the melt inlet side 4. The melt transport portion 16'' has an abutment surface 62 along a portion of its outer periphery 60 that conically taperes from the melt inlet side to the melt outlet side, and the abutment surface 62 corresponds to the receiving surface 58 of the receiving portion 24''. As shown in FIG. 7, the abutment surface 62 preferably extends over approximately half of the total depth TG of the melt transport portion 16''.

[0073] For the design of the receiving portion 40 of the melt transport portion 16" for the intermediate portion 20 and the design of the intermediate portion 20 itself, please refer to the above description of the embodiment shown in Figures 4 and 5. Although not shown in detail, material recesses 25' may also be provided in the abutment surface 62 and the receiving portion 40 or recessed area of ​​the melt transport portion 16" to form an air gap 25 between the outer ring 18" and adjacent areas of the intermediate portion 20.

[0074] For the basic design of the melt transport section 16" of the corresponding outer ring 18", see, for example, the above-described embodiment with regard to the melt flow path 14, the inlets and outlets 8, 10, and the heating path 54, the inlets and outlets 56, 56' for the heat transfer medium. As in the above-described embodiment, the heating path 54 preferably extends along a portion of the flow path 14 of the melt transport section 16" and is assigned to the outlet end side of the flow path 14. The heating path 54 is formed in the form of an annular space and extends adjacent to both the inside and outside of the annularly arranged flow path 14.

[0075] 8 shows another embodiment of a die plate assembly 1 having a multi-component die plate body 2 as viewed from the melt discharge side 6. The die plate body 2 comprises a melt transport section 16''' and an outer ring 18''', which are connected to each other by a rotary plug connection. The rotary plug connection 64 provides an alternative configuration of the receptacle 24''' for the melt transport section 16''' on the outer ring 18'''.

[0076] To form the receiving portion 24''' as a rotary plug connection 64, the outer ring 18''' is provided with at least one circumferentially extending groove-like recess 66 ( FIG. 9 ), and the outer ring 18''' is provided with an axially opening insertion region 68 designed to cooperate with the groove-like recess 66 and receive a corresponding locking portion 70 of the melt transport portion 16'''. To insert the melt transport portion 16''' into the outer ring 18''', they are first moved axially relative to each other until the locking portion 70 is aligned with the groove-like recess 66, and then the melt transport portion 16''' and the outer ring 18''' are rotated relative to each other about the central axis L. The outer ring 18''' preferably has a total of three such insertion regions 68 and corresponding groove-like recesses 66.

[0077] As shown in FIG. 10 , the outer periphery 60 of the melt transport section 16′″ is provided with three material protrusions 72 that protrude radially from the outer periphery 60 of the melt transport section 16′″ and extend circumferentially to form a stop 70. Each material protrusion 72 is positioned axially spaced apart from the melt inlet side 4 and the melt discharge side 6 of the melt transport section 16′″. This embodiment allows the melt transport section 16′″ to be inserted into the outer ring 18′″ from the melt discharge side 6 of the die plate assembly. As can be seen in FIG. 8 , the base member 36 of the intermediate section 20 is covered by a cover plate 74 on the melt discharge side 6. Around and outside the cover plate 74, under which a thermal insulator can be placed, are visible discharge ports 10 arranged in an annular shape, through which the molten strand discharged from the melt discharge side 6 flows. The outer ring 18′″ also has screw holders 22 into which electrical fastening screws 108 are inserted.

[0078] 11 and 12 show a modification of the embodiment shown in FIGS. 8 to 10. To position the outer ring 18''' and the melt transport section 16''', matching mating elements 76, 78 are formed on the outer ring 18''' and the melt transport section 16''', particularly on one of the insertion regions 68 and one of the locking portions 70 in the form of the material protrusions 72. The mating elements 76, 78 allow the outer ring 18' and the melt transport section 16''' to be joined in only one specific direction. This allows the inlets and outlets 56, 56' formed in the melt transport section 16''' and the outer ring 18''' as connection ports for the heat transfer medium to align with each other after the two parts are joined, preventing incorrect assembly.

[0079] 13 and 14 show another embodiment of the die plate assembly 1' of the present invention, in which the melt transport section 80 is divided into multiple segments 80', preferably ring segments, instead of the integral melt transport section 16. In this embodiment, the melt transport section 80 is divided into three segments 80'. Each segment 80' has a connection port as an inlet 82 to a heating channel 54 and at least one additional connection port as an outlet 82' for discharging the heat transfer medium from the heating channel. Therefore, the heat transfer medium required to heat the resin melt is supplied to each segment 80' via the corresponding heating channel 54.

[0080] The outer ring 18 of the die plate assembly 1′ has a receptacle 24 for a melt transport section 80 that is externally surrounded by the outer ring 18. To form the receptacle 24, the outer ring 18 has a stepped recess 28. The recess 28 has a radially extending stop surface 30 that contacts the melt transport section 80, particularly a segment 80′ thereof, when it is inserted into the outer ring 18.

[0081] The end faces 84 of the segments 80' are designed or arranged to form a seal with one another, thereby preventing the resin melt from passing between the segments 80' during operation of such a die plate assembly 1'.

[0082] 13 and 14, heating pipes 112 for the heat transfer medium are directly connected to each segment 80'. To allow the segments 80' thus formed to be inserted into the outer ring 18, radially extending recesses 86 are provided on the melt inlet side 4 of the outer ring 18 to accommodate the heating pipes 112 inserted into the outer ring 18 together with the segments 80'.

[0083] For the design of the receiving portion 40 of the intermediate section 20 in the melt transport section 16'' of Figures 8 to 12 or the melt transport section 80 of Figures 13 and 14, and the design of the intermediate section 20 itself, please refer to the description of the above-mentioned embodiment shown in Figures 4 and 5.

[0084] For the basic design of the melt transport section 16" of the corresponding outer ring 18", reference should be made to the above-described embodiment, e.g., with regard to the melt flow path 14, the inlets and outlets 8, 10, and the heating channel 54 for the heat transfer medium, and the inlets and outlets 56, 56' configured as connecting ports. As in the above-described embodiment, the heating channel 54 preferably extends along a portion of the flow path 14 of the melt transport section 16" and is assigned to the outlet end side of the flow path 14. The heating channel 54 is formed in the form of an annular space and extends adjacent to both the inside and the outside of the annularly arranged flow path 14.

[0085] In one embodiment of the present invention, the melt transport portions 16-16", 80 can be fabricated by additive manufacturing, particularly three-dimensional printing, which allows the melt transport portions 16-16", 80 to be integrally formed, including all recesses, undercuts, and cavities.

[0086] In one possible embodiment of the present invention, the melt transport section is fabricated using conventional manufacturing and processing methods such that the melt transport section 16-16''', 80 shown in FIGS. 15 and 16 is comprised of multiple parts. As shown in FIGS. 15 and 16, the melt transport section 16-16''', 80 includes at least one base member 90 having an inlet 8, an outlet 10, and a flow passage 14, and two separately constructed, generally cylindrical sleeve members 92, 92'. The sleeve members 92, 92' respectively define inner or outer wall regions 94, 94' of the melt transport section 16-16'". The sleeve members 92, 92' also define outer walls 96, 96' of the heating passage 54 facing away from the flow passage 14.

[0087] In one embodiment of the present invention, the sleeve members 92, 92' are sealingly connected at their contact surfaces 98, 98' to the region of the base member 90 of the melt transport section 16-16''' by means of, for example, sealing elements arranged on the base member 90. In another embodiment, a form-fit connection is formed in the region of the contact surfaces 90, 96, in particular the contact surfaces are welded to one another.

[0088] Furthermore, a preferred embodiment of a method 200 for repairing a pelletizing apparatus 100 having a die plate assembly 1, 1′ is shown in block diagram form in FIG. 17. The method 200 of the present invention allows, in particular, the separately formed melt transport section 16-16″, 80 shown in FIGS. 1-16 to be disassembled from the die plate assembly 1, 1′ of the pelletizing apparatus 100 and reattached after a reconditioning process, or to be replaced with another melt transport section 16-16″, 80.

[0089] In a first step 201, the die plate assemblies 1, 1′ are at least partially disassembled. The entire die plate assembly on the granulator 100 may be disassembled, or a portion of the die plate assembly 1, 1′ may be disassembled, in particular the melt transport section 16′, 16′″, which may be detached from the die plate body 2 at the melt discharge side 6.

[0090] In the next step 202, the melt transport section 16-16''' of the die plate assembly 1, 1' is replaced. The melt transport section 16-16''' may be replaced in its entirety, or only a segment 80' of the melt transport section 80 located on the die plate body 2, 2' may be replaced.

[0091] Finally, in step 203, at least a portion of the die plate assembly 1, 1' with the new melt transport section 16-16''', 80 or segment 80' attached is attached to the die plate holder or granulator. At this time, it is preferable to disassemble and attach the parts of the die plate assembly 1, 1' from the melt discharge side 6 of the die plate assembly.

[0092] When disassembling and installing the melt transport sections 16, 16''', 80 on the die plate body 2, 2', they are typically removed together with the intermediate section 20 of the die plate assembly 1, 1', and the melt transport sections 16, 16''', 80 and the intermediate section 20 are reinserted together into the outer ring 18-18''' of the die plate assembly.

[0093] In this specification, terms such as "first," "second," etc. are used to describe various elements, but these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, a first element can be called a second element, and similarly, a second element can be called a first element, without departing from the scope of the disclosure. In this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0094] When an element, such as a layer, region, or substrate, is described as being located "on" or extending "on" another element, the element may be located directly on or extending directly onto the other element, or intermediate elements may exist between them. On the other hand, when an element is described as being located "directly on" or extending "directly onto," there are no intermediate elements. Similarly, when an element, such as a layer, region, or substrate, is described as being located "above" or extending "above" another element, the element may be located directly on or extending directly onto the other element, or intermediate elements may exist between them. On the other hand, when an element is described as being located "directly above" or extending "directly above," there are no intermediate elements. When an element is described as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or intermediate elements may exist between them. On the other hand, when an element is described as being "directly connected" or "directly coupled," there are no intermediate elements.

[0095] Relative terms such as "bottom," "top," "upper," "lower," "horizontal," and "vertical" are used to describe the relationship of one element, layer, or region to another element, layer, or region as shown in the figures. It should be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

[0096] The terms used herein are for the purpose of describing particular aspects and are not intended to limit the scope of the disclosure. As used herein, the singular forms "a," "an," and "the" are construed to include the plural forms unless the context clearly dictates otherwise. Furthermore, it should be understood that as used herein, the term "comprises" is used to specify the presence of stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0097] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Furthermore, it should be understood that the terms used herein should be interpreted in a manner consistent with their meaning in the context of the present specification and the relevant art, and should not be interpreted in an idealized or overly formal sense unless explicitly defined as such.

[0098] The many features and advantages of the present disclosure will be apparent from the detailed description. Accordingly, it is intended by the appended claims to cover all features and advantages of the present disclosure that fall within the spirit and scope of the present disclosure. Moreover, since numerous modifications and variations will readily occur to those skilled in the art, the present disclosure is not limited to the exact construction and operation as illustrated or described, and therefore, all suitable variations and equivalents within the scope of the present disclosure are intended to be included. [Explanation of symbols]

[0099] 1, 1' Die plate assembly 2, 2' Die plate body 4. Melt inlet side 6 Melt discharge side 8 Introduction 10 Outlet 12 Melt transport area 14 Flow path 16, 16', 16'', 16'' Melt transport section 18, 18', 18'', 18'' outer ring 20 Middle section 22 Screw holder 24, 24', 24'', 24'' accommodation 25 Air gap 25' Material recess 26, 26' recess 27, 52 Fixing means 28, 28' recess 30, 30' stopping surface 32, 32' convex part 34, 34' contact surface 36 Base member 38 Guide Cone 40 Receptor 42 recess 44 Receptive Surface 46 Convex part 48 Contact surface 50 Alignment Elements 54 Heating path 56, 56' entrance and exit 58 Receptive Surface 60 perimeter 62 Contact surface 64 Rotating plug connection 66 Depression 68 Insertion Area 70 Locking part 72 Material protrusion 74 Cover Plate 76, 78 Mating elements 80 Molten Material Transport Section 80' segment 82, 82' entrance and exit 84 End face 86 Recess 90 Base material 92, 92' sleeve members 94, 94' wall area 95 Inner wall of outer ring 96, 96' wall 98, 98' contact surface 100 Granulation equipment 102 Underwater granulator 104 Driving means 106 Protective Cover 108 Fixing screw 112 Heating tube 114 Process water inlet 116 Process water outlet 118 Machine stand 120 spacer element 122 Housing Structure 200 ways 201 Decomposition Steps 202 Replacement Steps 203 Installation Steps L center axis TG total depth

Claims

1. A die plate assembly (1, 1') for a granulator (100) for producing granules from a liquid resin melt, in particular a thermoplastic material, comprising: At least one inlet (8) arranged on a melt inlet side (4) for introducing a melt, and a plurality of outlets (10) arranged on a melt outlet side for discharging the melt; a melt transport region (12) having at least one, preferably a plurality of melt flow channels (14) extending from the melt inlet side (4) to the melt outlet side (6), The melt transport region (12) is designed as a melt transport section (16-16''', 80) that is separable from the die plate assembly and reversibly attachable to and detachable from the die plate assembly (1, 1').

2. 2. The die plate assembly according to claim 1, wherein the die plate assembly (1, 1') is formed by at least the melt transport section (16-16''', 80) and the intermediate section (20) and / or the outer ring (18-18'''), and the melt transport section (16-16''', 80) is detachably coupled to the intermediate section (20) and / or the outer ring (18-18''').

3. 3. The die plate assembly according to claim 1, wherein the melt transport section (16-16''', 80) is substantially annular, and the flow channels (14) are spaced apart from one another, preferably arranged on at least one circle.

4. 4. The die plate assembly according to claim 2, wherein the outer ring (18-18''') of the die plate assembly (1, 1') has a receiving portion (24-24''') for positioning the melt transport portion (16-16''', 80) relative to the outer ring (18-18''').

5. 5. The die plate assembly according to claim 4, wherein the accommodations (24-24''') for the melt transport sections (16-16''', 80) are accessible from the melt inlet side (4) or the melt outlet side (6).

6. 6. The die plate assembly according to claim 4 or 5, characterized in that the outer ring (18, 18') has a preferably stepped recess (28, 28') with a substantially radially extending stop surface (30, 30') for receiving the melt transport portion (16, 16') so as to form the receiving portion (24, 24').

7. 7. The die plate assembly according to claim 6, wherein the melt transport portion (16, 16', 16''', 80) has at least one preferably circumferential protrusion (32, 32', 72) projecting radially outward, the protrusion having an abutment surface (34, 34') corresponding to the stop surface (30, 30') of the outer ring (18, 18').

8. 6. The die plate assembly according to claim 4, wherein the outer ring (18'') has a receiving surface (58) that conically reduces in diameter from the melt inlet side (4) to the melt outlet side (6) to form the receiving portion (24'').

9. 9. The die plate assembly according to claim 8, wherein the melt transport section (16'') has a conically tapered diameter from the melt inlet side (4) to the melt outlet side (6) and an abutment surface (62) defining a part of an outer periphery (60), the abutment surface corresponding to the receiving surface (58) of the outer ring (18'').

10. 6. The die plate assembly according to claim 4, wherein the receiving portion (24''') of the outer ring (18''') is designed as a rotary plug connection (64) having at least one groove-like recess (66) extending in the circumferential direction and an axially opening insertion area (68) for inserting a locking portion (70) of the melt transport portion (16''') into the recess (66).

11. 11. The die plate assembly according to claim 10, wherein the melt transport portion (16''') has at least one protrusion (72) that is axially spaced from the melt inlet side (4) and the melt outlet side (6) of the melt transport portion, protrudes radially from the outer periphery (60), and extends along a portion of the circumferential direction to form the stop portion (70).

12. 12. The die plate assembly according to claim 10 or 11, characterized in that the insertion region (68) and the protrusion (72) corresponding to the insertion region (68) are formed with mating elements (76, 78) that match each other as positioning means.

13. 13. The die plate assembly according to claim 2, wherein the outer ring (18', 18'") and the melt transport portion (16', 16'") are provided with corresponding recesses (26, 26') that are axially aligned with each other in operation and are arranged to secure the outer ring (18', 18'") and the melt transport portion (16', 16'") to each other.

14. 14. The die plate assembly according to claim 1, wherein the melt transport section (16-16''', 80) and / or the outer ring (18-18''') has at least one heating channel (54) for transporting a heat transfer medium or a heating conductor receiving section (22) for inserting an electric heating conductor (108), the heating channel (54) being arranged radially inward and / or outwardly offset with respect to the melt flow path (14).

15. 15. The die plate assembly according to claim 14, wherein the heating channel (54) in the melt transport section (16-16''', 80) extends along a portion of the flow path (14), and the heating channel (54) is allocated to an outlet end side of the flow path (14).

16. 16. The die plate assembly according to claim 14 or 15, wherein the heating channel (54) is an annular space, and the melt transport section (16-16''', 80) has at least one inlet (56, 82) for a heat transfer medium to enter the heating channel (54) and at least one outlet (56', 82') for a heat transfer medium to exit the heating channel (54).

17. 17. The die plate assembly according to claim 1, wherein the melt transport section (16-16''', 80) comprises at least one base member (90) surrounding the flow path (14) and at least one separately constructed, substantially cylindrical sleeve member (92, 92'), which defines the boundary of at least one inner and / or outer wall region (94, 94') of the melt transport section (16-16''', 80) and preferably defines an outer wall (96, 96') of the heating channel (54) facing away from the flow path (14).

18. 18. The die plate assembly of claim 17, wherein the sleeve member (92, 92') is hermetically connected or materially bonded to an adjacent region of the melt transport section (16-16''', 80).

19. Die plate assembly according to any one of the preceding claims, characterized in that the melt transport section (80) is divided into at least two separate segments (80'), preferably ring segments.

20. 20. The die plate assembly according to claim 19, characterized in that each segment (80') has at least one connection port for an inlet (82) to a heating channel (54) and at least one further connection port for an outlet (82') from said heating channel (54), preferably in that a radially extending recess (86) is provided in the outer ring (18) at the melt inlet side (4).

21. 21. The die plate assembly according to claim 2, wherein the melt transport section (16-16''', 80) has a receiving section (40) for holding the intermediate section (20) in the melt transport section (16-16''', 80), the intermediate section (20) preferably being made up of a plurality of individual parts.

22. 22. The die plate assembly according to claim 21, wherein the receiving portion (40) for the intermediate portion (20) is accessible from the melt discharge side (6), and the receiving portion (40) has at least one stepped recess (42) with a radially extending receiving surface (44) for the intermediate portion (20).

23. 23. The die plate assembly according to claim 22, wherein the intermediate portion (20) has a preferably circumferential convex portion (46) protruding radially outward, the convex portion having an abutment surface (34, 34') corresponding to the receiving surface (44) of the melt transport portion (16-16''', 80).

24. The die plate assembly according to any one of claims 2 to 23, characterized in that the intermediate portion (20) is composed of a substantially cylindrical base member (36) and a guide cone (38) connectable to the base member (36), and the intermediate portion (20) has at least one alignment element (50) for positioning the guide cone (38) on the base member (36).

25. 25. The die plate assembly according to any one of claims 2 to 24, characterized in that a preferably circumferential air gap (X) is formed at least in part between the outer ring (18-18''') and the melt transport section (16-16''', 80) and / or between the melt transport section (16-16''', 80) and the intermediate section (20).

26. 25. The die plate assembly according to any one of claims 2 to 24, wherein the outer ring (18-18''') and / or the intermediate portion (20) and preferably the sleeve member (92, 92') are made of a material having a lower thermal conductivity than the material forming the melt transport portion (16-16''', 80).

27. Die plate assembly according to any one of the preceding claims, characterized in that the melt transport section (16-16''', 80) is manufactured by additive manufacturing, in particular by three-dimensional printing.

28. A melt transport section (16-16''', 80) for transporting a melt, in particular a melt of a thermoplastic material, for a die plate assembly of a pelletizing device (100), in particular for a die plate assembly (1, 1') according to any one of claims 1 to 27, comprising: a melt inlet side (4) and a melt outlet side (6); a plurality of flow paths (14) extending from the melt inlet side (4) to the melt outlet side (6); The melt transport section (16-16'") is provided with an abutment surface (34, 34', 62) for an outer ring (18-18'") that can reversibly contact the outside of the melt transport section (16-16'", 80) and / or for an intermediate section (20) of a die plate assembly (1, 1') that can reversibly contact the inside of the melt transport section (16-16'", 80).

29. A granulation device (100) for producing granules from a melt, in particular a thermoplastic material, comprising: a die plate assembly (1, 1') for directing the melt; Granulating device, characterized in that the die plate assembly (1, 1') is a die plate assembly according to any one of claims 1 to 27.

30. A method (200) for repairing a granulator (100) having a die plate assembly, in particular a granulator according to claim 29, comprising: At least partially disassembling (201) the die plate assembly (1, 1'); replacing (202) the melt transport section (16-16''', 80) or segment (80') of the die plate assembly (1, 1'); and (203) attaching the new melt transport section (16-16''', 80) or the segment (80') attached to the die plate assembly (1, 1') to a die plate holder or the granulator (100), The parts of the die plate assembly (1, 1') are disassembled and installed from the melt discharge side (6).

31. 1. A die plate assembly for a granulator for producing granules from a liquid resin melt, particularly a thermoplastic material, comprising: At least one inlet arranged on a melt inlet side for introducing a melt, and a plurality of outlets arranged on a melt discharge side for discharging the melt; a melt transport region having at least one, and preferably a plurality of, melt flow passages extending from the melt inlet side to the melt outlet side; The die plate assembly, wherein the melt transport region is separable from the die plate assembly and is designed as a melt transport section that is reversibly attachable to and detachable from the die plate assembly.

32. 32. The die plate assembly of claim 31, wherein the die plate assembly is formed by at least the melt transport section and an intermediate section and / or an outer ring, and the melt transport section is detachably coupled to the intermediate section and / or the outer ring.

33. 33. A die plate assembly according to claim 31 or 32, wherein the melt transport section is generally annular, and the channels are spaced apart from one another, preferably arranged on at least one circle.

34. 34. The die plate assembly of claim 32 or 33, wherein the outer ring of the die plate assembly includes a receiving portion for positioning the melt transport portion relative to the outer ring.

35. 35. The die plate assembly of claim 34, wherein the accommodation for the melt transport is accessible from the melt entry side or the melt discharge side.

36. 36. A die plate assembly according to claim 34 or 35, wherein the outer ring has a recess, preferably stepped, with a generally radially extending stop surface for receiving the melt transport portion, to form the receiving portion.

37. 37. The die plate assembly of claim 36, wherein the melt transport portion has at least one, preferably circumferential, protrusion protruding radially outward, the protrusion having an abutment surface corresponding to the stop surface of the outer ring.

38. 36. The die plate assembly according to claim 34 or 35, wherein the outer ring has a receiving surface whose diameter conically decreases from the melt inlet side toward the melt outlet side to form the accommodation portion.

39. 39. The die plate assembly of claim 38, wherein the melt transport section has a conically tapered diameter from the melt inlet side toward the melt outlet side and an abutment surface defining a portion of an outer periphery, the abutment surface corresponding to the receiving surface of the outer ring.

40. 36. The die plate assembly according to claim 34 or 35, wherein the receiving portion of the outer ring is designed as a rotary plug connection having at least one groove-like recess extending in the circumferential direction and an axially opening insertion area for inserting the locking portion of the melt transport portion into the recess.

41. The die plate assembly of claim 40, wherein the melt transport portion has at least one protrusion that is axially spaced from the melt inlet side and the melt outlet side of the melt transport portion, protrudes radially from the outer periphery, and extends along a portion of the circumferential direction to form the engaging portion.

42. 42. The die plate assembly according to claim 40 or 41, wherein the insertion region and the protrusion corresponding to the insertion region are formed with mating elements as positioning means, the mating elements having matching shapes with each other.

43. 43. The die plate assembly of any one of claims 32 to 42, wherein the outer ring and the melt transport portion are provided with corresponding recesses that are axially aligned with each other during operation and are positioned to secure the outer ring and the melt transport portion to each other.

44. The die plate assembly according to any one of claims 31 to 43, wherein the melt transport section and / or the outer ring have at least one heating channel for transporting a heat medium or a heating conductor receiving section for inserting an electric heating conductor, the heating channel being offset radially inward and / or outward relative to the melt flow path.

45. 45. The die plate assembly of claim 44, wherein the heating channel in the melt transport section extends along a portion of the flow path, the heating channel being allocated toward an outlet end of the flow path.

46. 46. ​​The die plate assembly of claim 44 or 45, wherein the heating channel is an annular space, and the melt transport section has at least one inlet for a heat transfer medium to flow into the heating channel and at least one outlet for a heat transfer medium to flow out of the heating channel.

47. 47. The die plate assembly of claim 31, wherein the melt transporting section has at least one base member surrounding the flow path and at least one separately constructed, generally cylindrical sleeve member, the sleeve member defining the boundary of at least one inner and / or outer wall region of the melt transporting section, and preferably defining the outer wall of the heating channel facing away from the flow path.

48. 48. The die plate assembly of claim 47, wherein the sleeve member is hermetically connected or materially bonded to an adjacent region of the melt transport portion.

49. A die plate assembly according to any one of claims 31 to 48, wherein the melt transport section is divided into at least two separate segments, preferably ring segments.

50. 50. The die plate assembly of claim 49, wherein each segment has at least one connection port for an inlet to a heating channel and at least one further connection port for an outlet from said heating channel, and preferably a radially extending recess is provided in the outer ring at the melt inlet side.

51. A die plate assembly as described in any one of claims 32 to 50, wherein the melt transport section has a receiving portion for holding the intermediate section in the melt transport section, and the intermediate section is preferably composed of a plurality of individual parts.

52. 52. The die plate assembly of claim 51, wherein the receiving portion for the intermediate portion is accessible from the melt discharge side, and the receiving portion has at least one stepped recess having a radially extending receiving surface for the intermediate portion.

53. 53. The die plate assembly of claim 52, wherein the intermediate portion has a preferably circumferential convex portion that protrudes radially outward, the convex portion having an abutment surface that mates with the receiving surface of the melt transport portion.

54. The die plate assembly of any one of claims 32 to 53, wherein the intermediate portion is comprised of a substantially cylindrical base member and a guide cone connectable to the base member, and the intermediate portion has at least one alignment element for positioning the guide cone on the base member.

55. 55. The die plate assembly of claim 32, wherein a preferably circumferential air gap is formed at least partially between the outer ring and the melt transport section and / or between the melt transport section and the intermediate section.

56. A die plate assembly as described in any one of claims 32 to 54, wherein the outer ring and / or the intermediate portion and preferably the sleeve member are made of a material having a lower thermal conductivity than the material forming the melt transport portion.

57. A die plate assembly according to any one of claims 31 to 56, wherein the melt transport section is manufactured by additive manufacturing, in particular by three-dimensional printing.

58. A melt transport section for transporting a melt, in particular a melt of a thermoplastic material, for a die plate assembly of a granulator, in particular for a die plate assembly according to any one of claims 31 to 57, comprising: a melt inlet side and a melt outlet side; a plurality of flow paths extending from the melt inlet side to the melt outlet side; The melt transport section is provided with an abutment surface for an outer ring that can reversibly contact the outside of the melt transport section and / or an intermediate portion of a die plate assembly that can reversibly contact the inside of the melt transport section.

59. A granulating device for producing granules from a melt, in particular a thermoplastic material, comprising: a die plate assembly for directing the melt; A granulating apparatus, wherein the die plate assembly is the die plate assembly according to any one of claims 31 to 57.

60. 60. A method for repairing a granulating apparatus having a die plate assembly, in particular a granulating apparatus according to claim 59, comprising the steps of: at least partially disassembling the die plate assembly; replacing a melt transport section or segment of the die plate assembly; and attaching the part of the die plate assembly to which the new melt transport section or segment is attached to the die plate holder or the granulator; The method wherein the die plate assembly parts are disassembled and installed from the melt discharge side.

61. 1. A die plate assembly for a granulator for producing granules from a liquid resin melt, particularly a thermoplastic material, comprising: At least one inlet arranged on a melt inlet side for introducing a melt, and a plurality of outlets arranged on a melt discharge side for discharging the melt; a melt transport region having at least one, and preferably a plurality of, melt flow passages extending from the melt inlet side to the melt outlet side; The die plate assembly, wherein the melt transport region is separable from the die plate assembly and is designed as a melt transport section that is reversibly attachable to and detachable from the die plate assembly.

62. 62. The die plate assembly of claim 61, wherein the die plate assembly is formed by at least the melt transport section and an intermediate section and / or an outer ring, and the melt transport section is detachably coupled to the intermediate section and / or the outer ring.

63. 62. The die plate assembly of claim 61, wherein the melt transport region is generally annular, and the channels are spaced apart from one another, preferably arranged on at least one circle.

64. 63. The die plate assembly of claim 62, wherein the outer ring of the die plate assembly includes a receptacle for positioning the melt transport relative to the outer ring.

65. 65. The die plate assembly of claim 64, wherein the accommodation for the melt transport is accessible from the melt entry side or the melt discharge side.

66. 65. The die plate assembly of claim 64, wherein the outer ring has a recess, preferably stepped, with a generally radially extending stop surface for receiving the melt transport portion to form the receiving portion.

67. 67. The die plate assembly of claim 66, wherein the melt transport portion has at least one preferably circumferential protrusion protruding radially outward, the protrusion having an abutment surface corresponding to the stop surface of the outer ring.

68. 65. The die plate assembly of claim 64, wherein the outer ring has a receiving surface that conically narrows from the melt inlet side toward the melt outlet side to form the receiving portion.

69. 69. The die plate assembly of claim 68, wherein the melt transport portion has a conically tapered diameter from the melt inlet side toward the melt outlet side and an abutment surface defining a portion of an outer periphery, the abutment surface corresponding to the receiving surface of the outer ring.

70. 65. The die plate assembly of claim 64, wherein the receiving portion of the outer ring is designed as a rotary plug connection having at least one groove-like recess extending in the circumferential direction and an axially opening insertion area for inserting the locking portion of the melt transport portion into the recess.

71. The die plate assembly of claim 70, wherein the melt transport portion has at least one protrusion that is axially spaced from the melt inlet side and the melt outlet side of the melt transport portion, protrudes radially from the outer periphery, and extends along a portion of the circumferential direction to form the engaging portion.

72. The die plate assembly according to claim 70, wherein the positioning means are formed in the insertion region and the protrusion corresponding to the insertion region, and the matching mating elements are formed in the insertion region and the protrusion corresponding to the insertion region.

73. 63. The die plate assembly of claim 62, wherein the outer ring and the melt transport portion are provided with corresponding recesses that are axially aligned with one another during operation and are positioned to secure the outer ring and the melt transport portion to one another.

74. 74. The die plate assembly of claim 73, wherein the melt transport section and / or the outer ring have at least one heating channel for transporting a heat medium or a heating conductor receiving section for inserting an electric heating conductor, the heating channel being offset radially inward and / or outward relative to the melt flow path.

75. 75. The die plate assembly of claim 74, wherein the heating channel within the melt transport section extends along a portion of the flow path, the heating channel being allocated toward an outlet end of the flow path.

76. 75. The die plate assembly of claim 74, wherein the heating channel is an annular space, and the melt transport section has at least one inlet for a heat transfer medium to enter the heating channel and at least one outlet for a heat transfer medium to exit the heating channel.

77. 62. The die plate assembly of claim 61, wherein the melt transport section has at least one base member surrounding the flow path and at least one separately constructed, generally cylindrical sleeve member, the sleeve member defining the boundary of at least one inner and / or outer wall region of the melt transport section and preferably defining the outer wall of the heating channel facing away from the flow path.

78. 78. The die plate assembly of claim 77, wherein the sleeve member is hermetically connected or materially bonded to an adjacent region of the melt transport portion.

79. 62. The die plate assembly of claim 61, wherein the melt transport section is divided into at least two separate segments, preferably ring segments.

80. 80. The die plate assembly of claim 79, wherein each segment has at least one connection port for an inlet to a heating channel and at least one further connection port for an outlet from said heating channel, and preferably a radially extending recess is provided in the outer ring at the melt inlet side.

81. 63. The die plate assembly of claim 62, wherein the melt transport section has a receiving portion for holding the intermediate section in the melt transport section, the intermediate section preferably being comprised of a plurality of individual pieces.

82. 82. The die plate assembly of claim 81, wherein the receiving portion for the intermediate portion is accessible from the melt discharge side, and the receiving portion has at least one stepped recess having a radially extending receiving surface for the intermediate portion.

83. 83. The die plate assembly of claim 82, wherein the intermediate portion has a preferably circumferential convex portion that protrudes radially outward, the convex portion having an abutment surface that corresponds to the receiving surface of the melt transport portion.

84. 63. The die plate assembly of claim 62, wherein the intermediate portion comprises a generally cylindrical base member and a guide cone connectable to the base member, the intermediate portion having at least one alignment element for positioning the guide cone on the base member.

85. 63. The die plate assembly of claim 62, wherein a preferably circumferential air gap is formed at least partially between the outer ring and the melt transport section and / or between the melt transport section and the intermediate section.

86. 78. The die plate assembly of claim 77, wherein the outer ring and / or the intermediate portion and preferably the sleeve member are constructed from a material that has a lower thermal conductivity than the material forming the melt transport portion.

87. 62. The die plate assembly according to claim 61, wherein the melt transport portion is manufactured by additive manufacturing, in particular by three-dimensional printing.

88. A melt transport section for transporting a melt, in particular a melt of a thermoplastic material, for a die plate assembly of a granulator, in particular for the die plate assembly according to claim 61, comprising: a melt inlet side and a melt outlet side; a plurality of flow paths extending from the melt inlet side to the melt outlet side; The melt transport section is provided with an abutment surface for an outer ring that can reversibly contact the outside of the melt transport section and / or an intermediate portion of a die plate assembly that can reversibly contact the inside of the melt transport section.

89. A granulating device for producing granules from a melt, in particular a thermoplastic material, comprising: a die plate assembly for directing the melt; 62. A granulating apparatus, wherein the die plate assembly is the die plate assembly of claim 61.

90. 90. A method for repairing a granulating apparatus having a die plate assembly, in particular a granulating apparatus according to claim 89, comprising the steps of: at least partially disassembling the die plate assembly; replacing a melt transport section or segment of the die plate assembly; and attaching the part of the die plate assembly to which the new melt transport section or segment is attached to the die plate holder or the granulator; The method wherein the die plate assembly parts are disassembled and installed from the melt discharge side.

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