US-12617125-B2 - Pelletizing apparatus for the production of pellets from a melt flow and related operating and maintenance method

US12617125B2US 12617125 B2US12617125 B2US 12617125B2US-12617125-B2

Abstract

A pelletizing apparatus for the production of pellets from a melt flow comprising a pelletizer ( 12, 112 ), a cutting chamber ( 14, 114, 172 ), and a suspension structure ( 4, 104 ) for suspension of the pelletizer ( 12, 112 ) and/or the cutting chamber, wherein the suspension structure ( 4, 104 ) has a stationary portion ( 8, 108 ) and a portion ( 6, 106 ) connected rotatably about an axis of rotation ( 18, 118 ) to the stationary portion ( 8, 108 ) by means of a joint ( 16, 116 ). According to the invention it is proposed that the pivotable portion ( 6, 106 ) has a substantially horizontal support arm ( 20, 120 ) which extends from the axis of rotation ( 18, 118 ) and has a distal end ( 22, 122 ), wherein in the region of the distal end ( 22, 122 ) the pivotable portion ( 6, 106 ) has a support ( 10, 110 ) adapted to support the pivotable portion ( 6, 106 ) in a vertical direction ( 24, 124 ).

Inventors

Nikolai Schnellbach
Stefan Wöstmann

Assignees

NORDSON CORPORATION

Dates

Publication Date: 20260505
Application Date: 20210623
Priority Date: 20200624

Claims (20)

1 . A pelletizing apparatus for producing pellets from a melt flow comprising a pelletizer, a cutting chamber, and a suspension structure for suspension of the pelletizer and/or the cutting chamber, wherein the suspension structure has a stationary portion and a pivotable portion connected rotatably about an axis of rotation to the stationary portion by means of a joint, wherein the pivotable portion has a support arm which extends from the axis of rotation and has a distal end spaced from the axis of rotation in a distal direction, wherein the pivotable portion has, in a region of the distal end, a vertical support adapted to support the pivotable portion in a vertical direction, and wherein the pivotable portion comprises or is formed from at least one substantially horizontally extending runner rail extending along a longitudinal axis that extends from the axis of rotation to the distal end of the support arm, wherein the at least one substantially horizontally extending runner rail is adapted to mount the pelletizer in a suspended relationship moveably along the longitudinal axis, wherein the vertical support is offset from the axis of rotation and the stationary portion along the distal direction, which extends along the longitudinal axis, and wherein the vertical support is configured to vertically support the at least one substantially horizontally extending runner rail.
2 . A pelletizing apparatus according to claim 1 wherein the vertical support has rollers at its underside.
3 . A pelletizing apparatus according claim 1 wherein the vertical support extends substantially vertically.
4 . A pelletizing apparatus according to claim 1 wherein the support arm is provided by at least one runner rail.
5 . A pelletizing apparatus according to claim 1 wherein the pelletizer is accommodated in a carrier structure, wherein the carrier structure can be reversibly connected to at least one runner rail and has at least one adjusting means adapted to set a vertical position of the pelletizer.
6 . A pelletizing apparatus according to claim 1 wherein a process water feed is fluid-conductingly coupled to the cutting chamber and a process water and pellet discharge is fluid-conductingly coupled to the cutting chamber, wherein the process water feed and the process water and pellet discharge are arranged on the stationary portion of the suspension structure.
7 . A pelletizing apparatus according to claim 1 , wherein the at least one substantially horizontally extending runner rail is at least one substantially horizontally extending first runner rail, wherein the longitudinal axis is a first longitudinal axis, wherein the stationary portion of the suspension structure has at least one substantially horizontally extending second runner rail having a second longitudinal axis, the pelletizing apparatus further has a start-up valve connected fluid-conductingly to the cutting chamber, and that the at least one substantially horizontally extending second runner rail is adapted to carry the cutting chamber and/or the start-up valve moveably along the second longitudinal axis.
8 . A pelletizing apparatus according to claim 1 wherein the stationary portion of the suspension structure has two substantially vertical supports and a substantially horizontally extending carrier portion connecting the vertical supports, wherein a second runner rail is arranged on the carrier portion.
9 . A pelletizing apparatus according to claim 1 wherein a start-up valve has a central axis, wherein the axis of rotation of the suspension structure substantially corresponds to the central axis.
10 . A method of maintaining a pelletizing apparatus according to claim 1 , comprising the steps: providing the cutting chamber suspended moveably relative to an extruder of the pelletizing apparatus, wherein the extruder is coupled to the cutting chamber and the pelletizer in a production configuration; pivoting the pelletizer away from the cutting chamber; moving the cutting chamber away from the extruder; and maintaining the extruder, including removing and maintaining an extrusion screw of the extruder.
11 . A method according to claim 10 wherein the step of moving the cutting chamber away from the extruder includes the step: moving away a valve, which is coupled to the cutting chamber.
12 . A pelletizing apparatus for producing pellets from a melt flow comprising a pelletizer, a cutting chamber, and a suspension structure for suspension of the pelletizer and/or the cutting chamber, wherein the suspension structure has a stationary portion and a pivotable portion connected rotatably about an axis of rotation to the stationary portion by means of a joint, wherein the pivotable portion has a support arm which extends from the axis of rotation and has a distal end, wherein the pivotable portion has, in a region of the distal end, a vertical support adapted to support the pivotable portion in a vertical direction, wherein the cutting chamber is a first cutting chamber and the pelletizing apparatus has an additional second cutting chamber, wherein the first and second cutting chambers are fluid-conductingly coupled to a start-up valve, and wherein the pelletizer is adapted to be selectively coupled to the first cutting chamber or the second cutting chamber by pivoting the pivotable portion.
13 . A pelletizing apparatus according to claim 12 wherein the start-up valve is in a form of a 4/3 directional control valve.
14 . A pelletizing apparatus according to claim 12 wherein the pivotable portion has at least one substantially horizontally extending runner rail having a longitudinal axis or is formed therefrom, wherein the runner rail is adapted to mount the pelletizer in suspended relationship moveably along the longitudinal axis.
15 . A pelletizing apparatus according to claim 12 wherein the first cutting chamber and the second cutting chamber are coupled to a common process water feed and/or process water and pellet discharge.
16 . A pelletizing apparatus according to claim 12 wherein the cutting chamber has a first transverse axis and the second cutting chamber has a second transverse axis, wherein the cutting chamber is so arranged relative to the second cutting chamber that the first transverse axis assumes an angle of 45° to 135°, relative to the second transverse axis.
17 . A method of operating a pelletizing apparatus according to claim 12 , comprising the steps: providing the first cutting chamber and the second cutting chamber, wherein the first cutting chamber and the second cutting chamber respectively have a heatable apertured plate, providing the pelletizer arranged pivotably relative to the first and second cutting chambers, coupling the pelletizer to the first cutting chamber and producing the pellets, preheating the apertured plate of the second cutting chamber during the producing of pellets in the first cutting chamber, and pivoting the pelletizer from the first cutting chamber to the second cutting chamber after termination of the preheating of the apertured plate of the second cutting chamber.
18 . A method according to claim 17 and further comprising the steps: providing the start-up valve, wherein the start-up valve has a bottom position in which melt is fed to neither of the first and second cutting chambers, a first production position in which the melt fluid is fed exclusively to the first cutting chamber and a second production position in which the melt is fed exclusively to the second cutting chamber; switching over the start-up valve into the bottom position prior to the pivoting of the pelletizer from the first cutting chamber to the second cutting chamber; and switching over the start-up valve into the second production position after the pivoting of the pelletizer from the first cutting chamber to the second cutting chamber.
19 . A pelletizing apparatus according to claim 12 , wherein when the pelletizer is coupled to one of the first cutting chamber and the second cutting chamber, the pelletizer is configured to be decoupled from the one of the first cutting chamber and the second cutting chamber and then coupled to another one of the first cutting chamber and the second cutting chamber.
20 . A pelletizing apparatus according to claim 12 , wherein the distal end of the support arm is spaced from the axis of rotation in a distal direction, wherein a longitudinal axis extends from the axis of rotation to the distal end of the support arm, wherein the vertical support is offset from the axis of rotation and the stationary portion along the distal direction, which extends along the longitudinal axis, and wherein the vertical support is configured to vertically support the support arm.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage Application of International Patent App. No. PCT/US2021/038568, filed Jun. 23, 2021, which claims priority to European Patent Application No. 20182058.6, filed Jun. 24, 2020, the entire disclosures of both of which are hereby incorporated by reference as if set forth in their entirety herein. FIELD OF THE INVENTION The invention concerns a pelletizing apparatus for the production of pellets from a melt flow comprising a pelletizer, a cutting chamber, and a suspension structure for suspension of the pelletizer and/or the cutting chamber, wherein the suspension structure has a stationary portion and a portion connected rotatably about an axis of rotation to the stationary portion by means of a joint. BACKGROUND TO THE INVENTION Such pelletizing apparatuses for the production of pellets from a melt flow comprising a liquefied plastic are known from the state of the art. They are based on the functional principle that melt, for example in the form of a multiplicity of melt strands, is fed to a cutting chamber, wherein the melt is then cooled in the cutting chamber by means of the feed of a fluid and comminuted by means of a pelletizer. The pelletization method in question is also referred to as underwater pelletization. Particularly in the event of changes in material in respect of the melt or also in relation to maintenance operations which are to be regularly carried out the individual components of a pelletization apparatus are to be separated from each other, for example the pelletizer from the cutting chamber. To make that easier pelletizing apparatuses in which the pelletizer is mounted moveably on a rail system with respect to a stationarily arranged cutting chamber and pelletizing apparatuses in which the pelletizer and/or the cutting chamber are mounted in suspended relationship on a carrier structure are known from the state of the art. Such a suspended mounting of a pelletizer is known for example from EP 3 308 920 B1. The document in question discloses suspension of a pelletizer on a pivotal arm with a plurality of pivot joints, wherein the pivotal arm is mounted on a single suspension base. It is found that the described state of the art suffers from the disadvantage that such a suspension arrangement on a single suspension base requires the elements of the pivotal arm to be of massive dimensions as, by virtue of the typically high masses of the pelletizers, high levels of moment are applied to the suspension base by way of a lever arm formed by the pivotal arm. Such an apparatus is therefore suitable at most only for smaller and lighter pelletizers. In addition there is found to be the disadvantage that only the pelletizer can be pivoted by means of the arrangement in question, in relation to the further components of the pelletizing apparatus. If further components of the pelletizing apparatus are to be subjected to maintenance then the previously known suspension arrangement is unable in that respect to provide any support. SUMMARY OF THE INVENTION With that background in mind the object of the present invention is to develop a pelletizing apparatus of the kind set forth in the opening part of this specification such that the disadvantages encountered in the state of the art are overcome to the greatest possible extent. In particular the invention seeks to provide an apparatus which allows suspended mounting of a pelletizer and/or a cutting chamber, which at the same time is as easy and inexpensive to produce as possible and in addition is suitable even for suspending heavy pelletizers. According to the invention that object is attained in a pelletizing apparatus of the kind set forth in the opening part of this specification in that the pivotable portion has a substantially horizontal support arm which extends from the axis of rotation and has a distal end, wherein in the region of the distal end the pivotable portion has a support adapted to support the pivotable portion in a vertical direction (claim 1). The invention makes use of the realisation that a support means for the pivotable portion by means of a support arranged at a distal end of the horizontal support arm is advantageously suitable for supporting the pivotable portion so that it can mount heavy pelletizers in suspended relationship and thus can be of dimensions which are as material-saving and inexpensive as possible. Such a pelletizing apparatus advantageously permits pivotal movement of the pelletizer with respect to the cutting chamber, for example for maintenance of the components or for cleaning thereof upon a change in material. In addition the ground footprint required for the operation of such a pelletizing apparatus in a manufacturing environment is minimised. A development of the invention provides that the support has rollers at its underside. The provision of such rollers has proven to be advantageous to permit easy pivotablility of the pivot