Patent Publication Number: US-2022212391-A1

Title: Die Plate Heating/changing System And Method For Changing Plates In A Pelletizer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage Application of International Patent App. No. PCT/US2020/034612, filed May 27, 2020, which claims the benefit of U.S. Provisional Patent App. No. 62/856,271, filed Jun. 3, 2019, the entire disclosures of both of which are hereby incorporated by reference as if set forth in their entirety herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to die plate changing systems, and more particularly to die plate changing systems configured to hold and heat two die plates in a pelletizing system. 
     BACKGROUND 
     Conventionally, pelletizing systems can be utilized to produce pellets of material from a molten stream of the material, which can be an adhesive. In such pelletizing systems, a diverter valve and a die plate are operably connected to a pelletizer. In such an arrangement, the die plate has a plurality of holes therein and is mounted between the diverter valve and the pelletizer, specifically at the entrance to the pelletizer. The pelletizer then includes a rotating cutting head having cutting blades positioned adjacent a face of the die plate, from which streams of molten material flow. The rotating cutting head cuts the streams of material into pellets of various sizes depending upon the extrusion flow rate through the holes in the die plate and the speed of rotation of the cutting head. The pellets can be received by a flow of water, which cools the pellets and serves to carry the pellets away from the pelletizing assembly. 
     During operation of pelletizing systems, it can become necessary to replace the die plate. This can be necessary in order to produce pellets of different sizes, perform routine maintenance, fix an issue affecting operation, etc. However, replacing a die plate can place a high burden on a pelletizing operation, as pellet production must stop, the pelletizing system at least partially disassembled, the currently used die plate removed, and a new die plate installed. Further, the new die plate must be heated after installation before a pelletizing operation can begin again. This further lengthens downtime between pelletizing operations and increases pellet production costs. 
     Therefore, there is a need for a die plate changing system capable of holding and heating two die plates in a pelletizing system. 
     SUMMARY 
     An embodiment of the present disclosure is a die plate changing system configured to hold first and second die plates and selectively transition the first and second die plates into and out of communication with a material source. The die plate changing system comprises a frame having a body defining a first recess configured to receive the first die plate and a second recess configured to receive the second die plate, where the first and second die plates are disposed in the first and second recesses, respectively, and are heated. The die plate changing system also includes a movement assembly operably coupled to the frame and configured to selectively move the frame between a first position, where the first die plate is configured to receive material from the material source, and a second position, where the second die plate is configured to receive the material from the material source. 
     Another embodiment of the present disclosure is a method of changing die plates in a pelletizing system. The method comprises heating a first die plate and providing a material to the first die plate when the frame is in a first position. The method also includes heating a second die plate, moving the frame from the first position to a second position, and providing the material to the second die plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present application is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the subject matter, there are shown in the drawings exemplary embodiments of the subject matter; however, the presently disclosed subject matter is not limited to the specific methods, devices, and systems disclosed. In the drawings: 
         FIG. 1A  is a perspective view of a pelletizing system according to an embodiment of the present disclosure; 
         FIG. 1B  is an alternative perspective view of the pelletizing system shown in  FIG. 1A ; 
         FIG. 2  is a cross-sectional view of the pelletizing system shown in  FIG. 1A , taken along line  2 - 2  in  FIG. 1B ; 
         FIG. 3  is a front view of the die plate changing system of the pelletizing system shown in  FIG. 1A ; 
         FIG. 4  is a cross-sectional view of a portion of the die plate changing system shown in  FIG. 3 , taken along line  4 - 4  shown in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of a portion of the die plate changing system shown in  FIG. 3 , taken along line  5 - 5  shown in  FIG. 2 ; 
         FIG. 6A  is a perspective view of a pelletizing system according to another embodiment of the present disclosure; 
         FIG. 6B  is an alternative perspective view of the pelletizing system shown in  FIG. 6A ; 
         FIG. 7  is a cross-sectional view of the pelletizing system shown in  FIG. 6A , taken along line  7 - 7  shown in  FIG. 6B ; 
         FIG. 8  is a cross-sectional view of the die plate changing system of the pelletizing system shown in  FIG. 6A , taken along line  8 - 8  shown in  FIG. 7 ; and 
         FIG. 9  is a process flow diagram of a method of changing die plates in a pelletizing system according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Described herein is a pelletizing system  10  configured to create pellets P from a flow of liquid material L. The pelletizing system  10  includes a die plate changing system  70 ,  370  configured to hold and heat first and second die plates  25 ,  50 ,  325 ,  350 . Certain terminology is used to describe the pelletizing system  10  in the following description for convenience only and is not limiting. The words “right”, “left”, “lower,” and “upper” designate directions in the drawings to which reference is made. The words “inner” and “outer” refer to directions toward and away from, respectively, the geometric center of the description to describe the pelletizing system  10  and related parts thereof. The terminology includes the above-listed words, derivatives thereof and words of similar import. 
     Unless otherwise specified herein, the terms “longitudinal,” “lateral,” and “vertical” are used to describe the orthogonal directional components of various components of the pelletizing system  10  as designated by the longitudinal direction  2 , lateral direction  4 , and vertical direction  6 . It should be appreciated that while the longitudinal and lateral directions  2 ,  4  are illustrated as extending along a horizontal plane, and the vertical direction  6  is illustrated as extending along a vertical plane, the planes that encompass the various directions may differ during use. 
     Referring to  FIGS. 1A-3 , a pelletizing system  10  according to an embodiment of the present disclosure is depicted. The pelletizing system  10  can include a material source in fluid communication with an extruder (not shown), where the material source is configured to receive a flow of the liquid material L from the extruder. In one example, the material source can be a diverter valve  14 , although examples of the disclosure are not so limited. The diverter valve  14  can define a body that extends from a first end  14   a  to a second end opposite the first end  14   a  along the longitudinal direction  2 , as well as a passage  18  that extends through the diverter valve  14  from the first end  14   a  to the second end  14   b . The passage  18  can be configured to receive the flow of liquid material L from the extruder at the first end  14   a , such that the flow of liquid material L flows through the passage  18  of the diverter valve  14  along the longitudinal direction  2 . A bypass valve piston  20  can be attached to the diverter valve  14  and in fluid communication with the passage  18 . The bypass valve piston  20  can be configured to selectively divert the flow of liquid material L from the passage  18 , such as to a trolley for recycling or disposal of the liquid material L. This diversion can occur during breaks in a pelletizing operation or when a component of the pelletizing system  10  is being serviced or replaced. 
     A second die plate  50  can be positioned adjacent the second end  14   b  of the diverter valve  14 , such that the second die plate  50  is configured to receive the flow of liquid material L exiting the passage  18  of the diverter valve  14 . The second die plate  50  can be supported by the frame  75  of a die plate changing system  70 , where first and second die plates  25 ,  50  and the die plate changing system  70  will be discussed further below. The second die plate  50  can have a body  58  defining a plurality of passages  61  extending therethrough. Each of the passages  61  can define a diameter that correlates to the diameter of the pellets P produced by the pelletizing system  10 . In relation to other features of the pelletizing system  10 , the diameter of each of the passage  61  can be substantially smaller than that of the passage  18  of the diverter valve  14 . The flow of liquid material L can be pressurized to an extent that it is forced through the passage  61  of the second die plate  50 , producing elongated rods of the liquid material L. The liquid material L is then forced into an output line  124 , as will be described further below. 
     The pelletizing system  10  can further include a pelletizer  100 . The pelletizer  100  can be positioned on tracks  102 , such that the pelletizer  100  can be moved away from other components of the pelletizing system  10 , such as the die plate changing system  70 , during certain maintenance procedures, such as a die plate changing operation. The pelletizer  100  can comprise a motor  104 , as well as a shaft  108  extending from the motor  104  to a cutting head  112 . The cutting head  112  can be positioned within a cutting chamber  122  adjacent the second die plate  50 , specifically at a side of the second die plate  50  opposite the diverter valve  14 . In operation, the motor  104  of the pelletizer  100  can be configured to rotate the cutting head  112  via the shaft  108 . The cutting head  112  can include a plurality of blades, such that the cutting head  112  is configured to cut the elongated rods of liquid material L exiting the second die plate  50  into discrete pellets P of a particular length. The length of the pellets P created by the cutting head  112  can be increased or decreased by adjusting the rotational speed of the cutting head  112 . 
     Continuing with  FIGS. 1A-3 , the pelletizing system  10  can include an input line  120  defining a water input  116 . The input line  120  can be configured to receive water W through the water input  116  from a water source (not shown), where the water source can be configured to provide room temperature or cooler water W to the pelleting system  10 . The input line  120  is configured to direct the water W through the pelletizing system  10  to a cutting chamber  122 . The cutting chamber  122  can be configured to receive the cutting head  112  and can be positioned adjacent the end of the second die plate  50  opposite the diverter valve  14 . The cutting chamber  122  can be configured to receive both the flow of water W from the input line  120  and the pellets P cut by the cutting head  112 . When the pellets P are placed into contact with the water W, the water W serves multiple purposes. First, as the water W can have a significantly lower temperature than the pellets P immediately after they exit the second die plate  50  and are cut by the cutting head  112 , the water W can cool the pellets P such that the pellets P maintain their as-cut size and shape. Second, the flow of water W can carry the pellets P away from the cutting head  112  through the pelletizing system  10 . Specifically, the flow of water W and pellets P can flow upwards along vertical direction  6  from the cutting chamber  122  and into an output line  124 . The output line  124  can extend from the cutting chamber  122  to a slurry output  128 . From the slurry output  128 , the mixture of pellets P and water W can flow to a pellet dryer (not shown), which can function to separate the water W from the pellets P, providing the operator of the pelletizing system  10  with a supply of substantially dry pellets P. 
     Now referring to  FIGS. 3-5 , the die plate changing system  70  and the first and second die plates  25 ,  50  will be described in greater detail. The first die plate  25  can comprise a body  28 , as well as a plurality of passages  31  extending through the body  28  along the longitudinal direction  2 . In the depicted embodiment, the passages  31  are positioned in a substantially ring-like arrangement, though in other embodiments it is contemplated that the passages  31  can be alternatively situated. The passages  31  can define substantially cylindrical, elongate bores that can be designed so as to correspond in diameter to the intended diameter of the pellets P produced by the pelletizing system  10 . As a result, the passages  31  can have alternative sizes and/or shapes so as to produce pellets P having other sizes. Further, though the first die plate  25  is shown as defining a particular number of passages  31 , the first die plate  25  can define any number of passages in other embodiments. 
     The first die plate  25  can further define a plurality of bores  34  extending through the upper end of the body  28  of the first die plate  25  along the longitudinal direction  2 . Each of the bores  34  can be positioned along the periphery of the first die plate  25 , though other positions for the bores  34  are contemplated. The bores  34  can be configured to each receive a fastener  35  so as to secure the first die plate  25  to the frame  75  of the die plate changing system  70 , where the frame  75  will be described further below. The fasteners  35  can be bolts, screws, pins, or any conventional fastener capable of extending through respective bores  34  so as to releasably couple the first die plate  25  to the frame  75 . The first die plate  25  can define an input passage  43  positioned at the lower end of the body  28 . The input passage  43  can extend from the channel  40  to an outer surface of the first die plate  25 . The input passage  43  can be configured to receive the heated liquid from the frame  75  and provide the heated liquid to the channel  40 . Though shown as positioned at the lower end of the body  28 , the input passage  43  can be otherwise positioned on the first die plate  25  as desired. The channel  40  can be configured to receive the heated liquid from the input passage  43  and distribute the heated liquid throughout the first die plate  25  so as to evenly heat the first die plate  25 . In a pelletizing operation, it is important to heat the first and second die plates  25 ,  50  so as to maintain the flow of liquid material L in a substantially liquid state as it is being forced through one of the first and second die plates  25 ,  50 . Undue cooling of the liquid material L within the first and second die plates  25 ,  50  can lead to clogging of the passages  31 ,  61 , thus disrupting the entire operation of the pelletizing system  10 . 
     In the depicted embodiment, the channel  40  is shown as having a substantially ring-like shape that extends radially around the entirety of the passages  31 . However, the channel  40  can be otherwise configured so as to heat the first die plate  25 . For example, it is contemplated that the channel  40  can define any combination of additional passages or channels or define various other shapes. The first die plate  25  can further define a first output passage  37   a  extending from the outer surface of the first die plate  25 , as well as a second output passage  37   b  spaced from the first output passage  37   a  that also extends from the outer surface of the first die plate  25 . Though depicted as positioned at the upper end of the first die plate  25 , the first and second output passages  37   a ,  37   b  can be otherwise located on the first die plate  25  as desired. Each of the first and second output passages  37   a ,  37   b  can be configured to receive the heated liquid from the channel  40  and direct the heated liquid to the frame  75 . The first and second output passages  37   a ,  37   b  can extend from the outer surface of the first die plate  25  to the channel  40 . Further, though the first die plate  25  is shown as defining two output passages  37   a ,  37   b  and one input passage  43 , the first die plate  25  can define more or less input and output passages in other embodiments. 
     Continuing with  FIGS. 3-5 , the pelletizing system  10  can include a second die plate  50 . The second die plate  50  can comprise a body  58 , as well as a plurality of passages  61  extending through the body  58  along the longitudinal direction  2 . In the depicted embodiment, the passages  61  are positioned in a substantially ring-like arrangement, though in other embodiments it is contemplated that the passages  61  can be alternatively situated. The passages  61  can define substantially cylindrical, elongate bores that can be designed so as to correspond in diameter to the intended diameter of the pellets P produced by the pelletizing system  10 . As a result, the passages  61  can have alternative sizes and/or shapes so as to produce pellets P having other sizes. Further, though the second die plate  50  is shown as defining a particular number of passages  61 , the second die plate  50  can define any number of passages in other embodiments. In the depicted embodiment, the passages  31 ,  61  of the first and second die plates  25 ,  50  are depicted as having substantially identical designs and arrangements. However, it is contemplated that the first and second die plates  25 ,  50  can have differently sized and/or arranged passages  31 ,  61 , such as when the die plate changing system  70  is being utilized to alternate between two different pelletizing operations. 
     The second die plate  50  can further define a plurality of bores  64  extending through the upper end of the body  58  of the second die plate  50  along the longitudinal direction  2 . Each of the bores  64  can be positioned along the periphery of the second die plate  50 , though other positions for the bores  64  are contemplated. The bores  64  can be configured to each receive a fastener, such as fastener  35  described above, so as to secure the second die plate  50  to the frame  75  of the die plate changing system  70 . The second die plate  50  can further define an input passage  69  positioned at the lower end of the body  58 . The input passage  69  can extend from the channel  68  to an outer surface of the second die plate  50 . The input passage  69  can be configured to receive the heated liquid from the frame  75  and provide the heated liquid to the channel  68 . Though shown as positioned at the lower end of the body  58 , the input passage  69  can be otherwise positioned on the second die plate  50  as desired. The channel  68  can be configured to receive the heated liquid from the input passage  69  and distribute the heated liquid throughout the second die plate  50  so as to evenly heat the second die plate  50 . 
     In the depicted embodiment, the channel  68  is shown as having a substantially ring-like shape that extends radially around the entirety of the passages  61 . However, the channel  68  can be otherwise configured so as to heat the second die plate  50 . For example, it is contemplated that the channel  68  can define any combination of additional passages or channels or define various other shapes. The second die plate  50  can also define a first output passage  67   a  extending from the outer surface of the second die plate  50 , as well as a second output passage  67   b  spaced from the first output passage  67   a  that also extends from the outer surface of the second die plate  50 . Though depicted as positioned at the upper end of the second die plate  50 , the first and second output passages  67   a ,  67   b  can be otherwise located on the second die plate  50  as desired. Each of the first and second output passages  67   a ,  67   b  can be configured to receive the heated liquid from the channel  68  and provide the heated liquid to the frame  75 . The first and second output passages  67   a ,  67   b  can extend from the outer surface of the second die plate  50  to the channel  68  that extends through the second die plate  50 . Further, though the second die plate  50  is shown as defining two output passages  67   a ,  67   b  and one input passage  69 , the second die plate  50  can define more or less input and output passages in other embodiments. 
     Continuing with  FIGS. 3-5 , the die plate changing system  70  will be described in greater detail. The die plate changing system  70  can be configured to hold the first and second die plates  25 ,  50  and selectively transition the first and second die plates  25 ,  50  into and out of communication with the diverter valve  14 . The die plate changing system  70  can include a frame  75 , where the frame  75  has a body  78 . The body  78  can define a front surface  78   a , as well as a rear surface  78   b  opposite the front surface  78   a  along the longitudinal direction  2 . The body  78  can also define a top surface  78   c , and a bottom surface  78   d  opposite the top surface  78   c  along the vertical direction  6 . Further, the body  78  can define a first side surface  78   e  and a second side surface  78   f  opposite the first side surface  78   e  along the lateral direction  4 . As such, the body  78  of the frame  75  can be substantially shaped as a rectangular prism. However other shapes and designs for the frame  75  are contemplated. Within the pelletizing system  10 , the front surface  78   a  of the frame  75  can be adjacent the diverter valve  14 , and the rear surface  78   b  can be adjacent the cutting head  112  of the pelletizer  100 . 
     The frame  75  can define a first recess  82   a  extending into the body  78  from the front surface  78   a , as well as a second recess  82   b  extending into the body  78  from the front surface  78   a . The first recess  82   a  is configured to receive the first die plate  25 , and the second recess  82   b  is configured to receive the second die plate  50 . Portions of the first and second recesses  82   a ,  82   b  can extend completely through the body  78  from the front surface  78   a  to the rear surface  78   b , such that the flow of liquid material L can flow through the passages  31 ,  61  of one of the first and second die plates  25 ,  50  when the first and second die plates  25 ,  50  are disposed within the first and second recesses  82   a ,  82   b . The frame  75  can include a plurality of bores  95   a  that are configured to align with the bores  34  of the first die plate  25  when the first die plate  25  is received within the first recess  82   a , and receive fasteners  35  therethrough so as to secure the first die plate  25  to the frame  75 . The frame  75  can also include a plurality of bores  95   b  that are configured to align with the bores  64  of the second die plate  50  when the second die plate  50  is received within the second recess  82   b , and receive fasteners  35  therethrough so as to secure the second die plate  25  to the frame  75 . The number, alignment, and shape of the bores  95   a ,  95   b  will generally correspond to that of the bores  34 ,  64  with which they are configured to align, as well as the fasteners  35  that they are configured to receive. However, like the bores  34 ,  64 , the bores  95   a ,  95   b  can be shaped and/or positioned differently than depicted in other embodiments. 
     The frame  75  can be configured to couple to the diverter valve  14  during a pelletizing operation. Specifically, the frame  75  can include a plurality of bores  95   a  positioned radially around the first recess  82   a , where the bores  95   a  are each configured to receive a respective fastener  98  so as to couple the frame  75  to the diverter valve  14  when the first die plate  25  is in fluid communication with the diverter valve  14  and the pelletizer  100 . The frame  75  can also include a plurality of bores  95   b  positioned radially around the second recess  82   b , where the bores  95   b  are each configured to receive a respective fastener  98  so as to couple the frame  75  to the diverter valve  14  when the second die plate  50  is in fluid communication with the diverter valve  14  and the pelletizer  100 . Though a particular number and arrangement of bores  95   a ,  95   b  is shown, more or less bores  95   a ,  95   b  can be included in the frame  75 , as well as bores  95   a ,  95   b  having different designs. It is contemplated that the fasteners  98  could be bolts, or any other type of conventional fastener capable of releasably coupling the frame  75  to the diverter valve  14 . 
     In operation, only one of the first and second die plates  25 ,  50  is in fluid communication with the diverter valve  14  and the pelletizer  100 . In previous pelletizing systems, the system would have to be disassembled in order to service and/or replace a die plate. In the pelletizing system  10 , the die plate changing system  70  can easily transition between positioning the first die plate  25  and the second die plate  50  in fluid communication with other aspects of the pelletizing system  10 . To do this, the die plate changing system  70  can include a movement assembly  204  operably coupled to the frame  75  and configured to selectively move the frame  75  between multiple positions. For example, the movement assembly  204  can be configured to move the frame  75  between a first position, where the first die plate  25  is configured to receive the liquid material from the diverter valve  14 , and a second position, where the second die plate  50  is configured to receive the material from the diverter valve  14 . The second position is explicitly shown in  FIGS. 1A-2 . 
     In the embodiment shown in  FIGS. 1-5 , the movement assembly  204  is configured to move the frame  75  linearly along the lateral direction  4  between the first and second positions. To do this, the movement assembly  204  can comprise a linear track  208 . The die plate changing system  70  can further include a support structure  200 , where the linear track  208  is coupled to the support structure  200 . The support structure  200  depicted can have an arch-shaped body comprising metal beams, though other shapes for the support structure  200  are contemplated. The pelletizing system  10  can further include first and second supports  216   a ,  216   b , where each of the first and second supports  216   a ,  216   b  are configured to extend from the frame  75  to the linear track  208  so as to couple the frame  75  to the linear track  208 . Specifically, the frame  75  can hang from the linear track  208  via the first and second supports  216   a ,  216   b . As such, the frame  75  is configured to selectively move along the linear track  208  between the first and second positions. To move the frame  75 , the die plate changing system  70  can include a motor  212  operatively coupled to the frame  75 . Specifically, the motor  212  can be coupled to the support structure  200 , the linear track  208 , and/or the first and second supports  216   a ,  216   b . The motor  212  can be configured to automatically move the frame  75  along the linear track  208  between the first and second directions, either upon commands received by a controller or upon direction by the operator of the pelletizing system  10 . Alternatively, the frame  75  can be manually transitioned between the first and second positions by the operator. To do this, the operator can manually apply a lateral force to the frame  75  and/or the first and second supports  216   a ,  216   b  so as to move the frame  75  along the linear track  208  into the desired first or second position. 
     In addition to moving between first and second positions so as to selectively place one of the first and second die plates  25 ,  50  in fluid communication with the diverter valve  14  and the pelletizer  100 , the die plate changing system  70  can further be configured to heat the first and second die plates  25 ,  50 . In other words, the die plate changing system  70  can heat both the one of the first and second die plates  25 ,  50  that is in fluid communication with the diverter valve  14  and the pelletizer  100 , as well as the other one of the first and second die plates  25 ,  50  that is not in fluid communication with the diverter valve  14  or the pelletizer  100 . In pelletizing systems, die plates must be heated before use so that the liquid material forced therethrough stays heated and maintains optimal flow characteristics. As a result, when a die plate must be replaced, additional downtime is conventionally needed to allow the newly installed die plate to sufficiently increase in temperature until a pelletizing operation can be performed. This additional downtime further increases the costs associated with performing a die plate changing operation. 
     In contrast, the die plate changing system  70 , and particularly the frame  75 , is configured to heat both the first and second die plates  25 ,  50  when the first and second die plates  25 ,  50  are disposed in the first and second recesses  82   a ,  82   b , respectively. As a result, the one of the die plates  25 ,  50  that is to replace the other die plate  25 ,  50  that is in fluid communication with the diverter valve  14  and pelletizer  100  can be brought up to temperature prior to installation, thus eliminating a previously-required time-consuming step in die plate replacement. To perform this function, the die plate changing system  70  can include a plurality of passages and valves for controlling a flow of heated liquid through the die plate changing system  70 . The heated liquid can be a heated oil or heated water, though other liquids are contemplated. 
     To supply the first die plate  25  with heated liquid, the die plate changing system  70  can include a first input passage  140  that extends from a first input valve  148  to a first input  86   a  defined by the frame  75 . The first input passage  140  can be configured to receive the heated liquid from a heated liquid source (not shown) and direct the heated liquid to the first input  86   a  of the plate. As the first input valve  148  is in fluid communication with the first input  86   a , the first input valve  148  can be configured to control the flow of heated liquid into the first input passage  140  and the first input  86   a . For example, the first input valve  148  can be configured to allow the heated liquid to flow to the first input  86   a  during a die plate heating operation, as well as selectively prevent the heated liquid from flowing to the first input  86   a  during a liquid drainage operation, which will be described further below. 
     As stated above, the frame  75  can include a first input  86   a  configured to receive the heated liquid from the first input passage  140 . The frame  75  can further include a first input passage  90   a  that extends from the first input  86   a  to the first recess  82   a . When the first input valve  148  is open, the first input passage  90   a  is configured to receive the heated liquid from the first input  86   a  and supply the first die plate  25  with the heated liquid. Specifically, the first input passage  90   a  can be in fluid communication with the input passage  43  of the first die plate  25 , where the input passage  43  directs the heated liquid into the channel  40  of the first die plate  25 , and then to the first and second output passage  37   a ,  37   b  of the first die plate  25 . The frame can also define first and second output passages  92   a ,  92   b , where each of the first and second output passages  92   a ,  92   b  extends from the first recess  82   a  to a first and second outputs  94   a ,  94   b , respectively. The first and second output passages  92   a ,  92   b  can be configured to receive the heated liquid from the first die plate  25 , specifically the first and second output passages  37   a ,  37   b  of the first die plate  25 , and direct the heated liquid to the first and second outputs  94   a ,  94   b , respectively. The die plate changing system  70  can further include a first output passage  172  that extends from the first and second outputs  94   a ,  94   b  to a first output valve  176 . Specifically, the first output passage  172  can include a first branch  172   a  that extends from the first output  94   a  and a second branch  172   b  that extends from the second output  94   b . As the first output valve  176  is in fluid communication with the first and second outputs  94   a ,  94   b , the first output valve  176  can be configured to selectively control the flow of heated liquid from the frame  75 , through the first output valve  176 , and back to the heated liquid supply or a used heated liquid collection area (not shown). For example, the first output valve  176  can be configured to allow the heated liquid to flow through the first output valve  176  during a die plate heating operation, as well as selectively prevent the heated liquid from flowing through the first output valve  176  during a liquid drainage operation, which will be described further below. 
     The die plate changing system  70  can include additional components that can be utilized in a drainage operation of the first die plate  25 . This can be performed when the first die plate  25  is no longer in operation, and the operator of the pelletizing system  10  needs to remove the first die plate  25  from the frame  75 , such as to install a new die plate or perform maintenance on the first die plate  25 . The die plate changing system  70  can include a first drainage passage  144  that extends from the first input passage  140  to a first drainage valve  152 , as well as a first ventilation passage  180  that extends from the first output passage  172 . When the first input valve  148  and the first output valve  176  are closed, and the first drainage valve  152  is open, the heated liquid can flow from within the frame  75  and the first die plate  25 , through the first drainage passage  144 , and out of the die plate changing system  70 . The first ventilation passage  180  can allow air to flow through the frame  75  and the first die plate  25  to replace the heated liquid exiting the frame  75  and first die plate  25  through the first drainage passage  144 . 
     Continuing with  FIGS. 3-5 , to supply the second die plate  50  with heated liquid, the die plate changing system  70  can include a second input passage  156  that extends from a second input valve  164  to a second input  86   b  defined by the frame  75 . The second input passage  156  can be configured to receive the heated liquid from a heated liquid source (not shown) and direct the heated liquid to the second input  86   b  of the frame  75 . As the second input valve  164  is in fluid communication with the second input  86   b , the second input valve  164  can be configured to control the flow of heated liquid into the second input passage  156  and the second input  86   b . For example, the second input valve  164  can be configured to allow the heated liquid to flow to the second input  86   b  during a die plate heating operation, as well as selectively prevent the heated liquid from flowing to the second input  86   b  during a liquid drainage operation, which will be described further below. 
     As stated above, the frame  75  can include a second input  86   b  configured to receive the heated liquid from the second input passage  156 . The frame  75  can further include a second input passage  90   b  that extends from the second input  86   b  to the second recess  82   b . When the second input valve  164  is open, the second input passage  90   b  is configured to receive the heated liquid from the second input  86   b  and supply the second die plate  50  with the heated liquid. Specifically, the second input passage  90   b  can be in fluid communication with the input passage  69  of the second die plate  50 , where the input passage  69  directs the heated liquid into the channel  68  of the second die plate  50 , and then to the first and second output passage  67   a ,  67   b  of the second die plate  50 . The frame  75  can also define third and fourth output passages  92   c ,  92   d , where each of the third and fourth output passages  92   c ,  92   d  extends from the second recess  82   b  to a third and fourth output  94   c ,  94   d , respectively. The third and fourth output passages  92   c ,  92   d  can be configured to receive the heated liquid from the second die plate  50 , specifically the first and second output passages  67   a ,  67   b  of the second die plate  50 , and direct the heated liquid to the third and fourth outputs  94   c ,  94   d , respectively. The die plate changing system  70  can further include a second output passage  184  that extends from the third and fourth outputs  94   c ,  94   d  to a second output valve  188 . Specifically, the second output passage  184  can include a first branch  184   a  that extends from the third output  94   c  and a second branch  184   b  that extends from the fourth output  94   d . As the second output valve  188  is in fluid communication with the third and fourth outputs  94   c ,  94   d , the second output valve  188  can be configured to selectively control the flow of heated liquid from the frame  75 , through the second output valve  188 , and back to the heated liquid supply or a used heated liquid collection area (not shown). For example, the second output valve  188  can be configured to allow the heated liquid to flowing through the second output valve  188  during a die plate heating operation, as well as selectively prevent the heated liquid from flowing through the second output valve  188  during a liquid drainage operation, which will be described further below. 
     The die plate changing system  70  can include additional components that can be utilized in a drainage operation of the second die plate  50 . This can be performed when the second die plate  50  is no longer in operation, and the operator of the pelletizing system  10  needs to remove the second die plate  50  from the frame  75 , such as to install a new die plate or perform maintenance on the second die plate  50 . The die plate changing system  70  can include a second drainage passage  160  that extends from the second input passage  156  to a second drainage valve  168 , as well as a second ventilation passage  192  that extends from the second output passage  184 . When the second input valve  164  and the second output valve  188  are closed, and the second drainage valve  168  is open, the heated liquid can flow from within the frame  75  and the second die plate  50 , through the second drainage passage  160 , and out of the die plate changing system  70 . The second ventilation passage  192  can allow air to flow through the frame  75  and the second die plate  50  to replace the heated liquid exiting the frame  75  and second die plate  50  through the second drainage passage  160 . 
     As described above, the die plate changing system  70  can include two fluidly isolated systems of passages for heating the first and second die plates  25 ,  50 , as well as the frame  75 , using a heated liquid. This allows each of the first and second die plates  25 ,  50  to be heated or drained of heated liquid and removed from the frame  75  independent from each other, thus allowing die plates to be used in future operations to be installed in advance and brought up to temperature before the die plate currently in fluid communication with the diverter valve  14  and the pelletizer  100  is to be removed from operation. As a result, the time required to perform a die plate changing operation is significantly reduced, which likewise reduces associated pelletizing operation costs. 
     Now referring to  FIGS. 6A-8 , another embodiment of a pelletizing system  310  will be described. The pelletizing system  310  can include a diverter valve  314  in fluid communication with an extruder (not shown), where the diverter valve  314  is configured to receive a flow of the liquid material L from the extruder. The diverter valve  314  can define a body that extends from a first end  314   a  to a second end opposite the first end  314   a  along the longitudinal direction  2 , as well as a passage  318  that extends through the diverter valve  314  from the first end  314   a  to the second end  314   b . The passage  318  can be configured to receive the flow of liquid material L from the extruder at the first end  314   a , such that the flow of liquid material L flows through the passage  318  of the diverter valve  314  along the longitudinal direction  2 . A bypass valve  320  can be attached to the diverter valve  314  and in fluid communication with the passage  318 . The bypass valve  320  can be configured to selectively divert the flow of liquid material L from the passage  318  to device for disposal or recycling, such as during breaks in a pelletizing operation or when a component of the pelletizing system  310  is being serviced or replaced. 
     A first die plate  325  can be positioned adjacent the second end  314   b  of the diverter valve  314 , such that the first die plate  325  is configured to receive the flow of liquid material L exiting the passage  318  of the diverter valve  314 . The first die plate  325  can be supported by the frame  375  of a die plate changing system  370 , where first and second die plates  325 ,  350  and the die plate changing system  370  will be discussed further below. The first die plate  325  can have a body  328  defining a plurality of passages  331  extending therethrough. Each of the passages  331  can define a diameter that correlates to the diameter of the pellets P produced by the pelletizing system  310 . In relation to other features of the pelletizing system  310 , the diameter of each of the passages  331  can be substantially smaller than that of the passage  318  of the diverter valve  314 . The flow of liquid material L can be pressurized to an extent that it is forced through the passages  331  of the first die plate  325 , producing elongated rods of the liquid material L. The liquid material L is then forced into an output line  424 , as will be described further below. 
     The pelletizing system  310  can further include a pelletizer  400 . The pelletizer  400  can comprise a motor  404 , as well as a shaft  408  extending from the motor  404  to a cutting head  412 . The cutting head  412  can be positioned within a cutting chamber  422  adjacent the first die plate  325 , at a side of the first die plate  325  opposite the diverter valve  314 . In operation, the motor  404  of the pelletizer  400  can be configured to rotate the cutting head  412  via the shaft  408 . The cutting head  412  can include a plurality of blades, such that the cutting head  412  is configured to cut the elongated rods of liquid material L exiting the first die plate  325  into discrete pellets P of a particular length. The length of the pellets P created by the cutting head  412  can be increased or decreased by adjusting the rotational speed of the cutting head  412 . 
     Continuing with  FIGS. 6A-8 , the pelletizing system  310  can include an input line  420  defining a water input  416 . The input line  420  can be configured to receive water W through the water input  416  from a water source (not shown), where the water source can be configured to provide room temperature or cooler water W to the pelleting system  310 . The input line  420  is configured to direct the water W through the pelletizing system  310  to a cutting chamber  422 . The cutting chamber  422  can be configured to receive the cutting head  412  and can be positioned adjacent the end of the first die plate  325  opposite the diverter valve  314 . The cutting chamber  422  can be configured to receive both the flow of water W from the input line  420  and the pellets P cut by the cutting head  412 . When the pellets P are placed into contact with the water W, the water W serves multiple purposes. First, as the water W can have a significantly lower temperature than the pellets P immediately after they exit the first die plate  325  and are cut by the cutting head  412 , the water W can cool the pellets P such that the pellets P maintain their as-cut size and shape. Second, the flow of water W can carry the pellets P away from the cutting head  412  through the pelletizing system  310 . Specifically, the flow of water W and pellets P can flow upwards along vertical direction  6  from the cutting chamber  422  and into an output line  424 . The output line  424  can extend from the cutting chamber  422  to a slurry output  428 . From the slurry output  428 , the mixture of pellets P and water W can flow to a pellet dryer (not shown), which can function to separate the water W from the pellets P, providing the operator of the pelletizing system  310  with a supply of substantially dry pellets P. 
     As stated above, the first die plate  325  can comprise a body  328 , as well as a plurality of passages  331  extending through the body  328  along the longitudinal direction  2 . In the depicted embodiment, the passages  331  are positioned in a substantially ring-like arrangement, though in other embodiments it is contemplated that the passages  331  can be alternatively situated. The passages  331  can define substantially cylindrical, elongate bores that can be designed so as to correspond in diameter to the intended diameter of the pellets P produced by the pelletizing system  310 . As a result, the passages  331  can have alternative sizes and/or shapes so as to produce pellets P having other sizes. Further, though the first die plate  325  is shown as defining a particular number of passages  331 , the first die plate  325  can define any number of passages in other embodiments. 
     The first die plate  325  can further define a plurality of bores  334  extending radially through the outer surface of the body  328  of the first die plate  325 . Each of the bores  334  can be spaced apart about the circumference of the first die plate  325 , though other positions for the bores  334  are contemplated. The bores  334  can be configured to each receive a fastener  335  so as to secure the first die plate  325  to the frame  375  of the die plate changing system  370 , where the frame  375  will be described further below. The fasteners  335  can be bolts, screws, pins, or any conventional fastener capable of extending through respective bores  334  so as to releasably couple the first die plate  325  to the frame  375 . In contrast with the first and second die plates  25 ,  50 , which are configured to be heated through receiving a flow of heated oil, the first die plate  325  can define a plurality of cartridge passages  337  extending radially through the outer surface of the body  328 , where each cartridge passage  337  is configured to receive a respective heating cartridge  388 . The heating cartridges  388  can be various types of electrical heating cartridges. When powered, the heating cartridges  388  can be configured to heat the first die plate  325  prior to and after placement into fluid communication with the diverter valve  314  and the pelletizer  400 . As shown, the outer circumference of the body  328  defines an alternating arrangement of bores  334  and cartridge passages  337 . However, it is contemplated that other arrangements and numbers of bores  334  and cartridge passages  337  can be utilized. 
     The pelletizing system  310  can also include a second die plate  350 . The second die plate  350  can comprise a body  358 , as well as a plurality of passages  361  extending through the body  358  along the longitudinal direction  2 . In the depicted embodiment, the passages  361  are positioned in a substantially ring-like arrangement, though in other embodiments it is contemplated that the passages  361  can be alternatively situated. The passages  361  can define substantially cylindrical, elongate bores that can be designed so as to correspond in diameter to the intended diameter of the pellets P produced by the pelletizing system  310 . As a result, the passages  361  can have alternative sizes and/or shapes so as to produce pellets P having other sizes. Further, though the second die plate  350  is shown as defining a particular number of passages  361 , the second die plate  350  can define any number of passages in other embodiments. 
     The second die plate  350  can further define a plurality of bores  364  extending radially through the outer surface of the body  358  of the second die plate  350 . Each of the bores  364  can be spaced apart about the circumference of the second die plate  350 , though other positions for the bores  364  are contemplated. The bores  364  can be configured to each receive a fastener  335  so as to secure the second die plate  350  to the frame  375  of the die plate changing system  370 . Like the first die plate  325 , the second die plate  350  can define a plurality of cartridge passages  367  extending radially through the outer surface of the body  358 , where each cartridge passage  367  is configured to receive a respective heating cartridge  388 . When powered, the heating cartridges  388  can be configured to heat the second die plate  350  prior to and after placement into fluid communication with the diverter valve  314  and the pelletizer  400 . As shown, the outer circumference of the body  358  defines an alternating arrangement of bores  364  and cartridge passages  367 . However, it is contemplated that other arrangements and numbers of bores  364  and cartridge passages  367  can be utilized. 
     Continuing with  FIGS. 6A-8 , the die plate changing system  370  will be described in greater detail. The die plate changing system  370  can be configured to hold the first and second die plates  325 ,  350  and electively transition the first and second die plates  325 ,  350  into and out of communication with the diverter valve  314 . The die plate changing system  370  can include a frame  375 , where the frame  375  has a body  378 . The body  378  can define a first recess  382   a  and a second recess  382   b  extending into the body  378 . The first recess  382   a  is configured to receive the first die plate  325 , and the second recess  382   b  is configured to receive the second die plate  350 . Portions of the first and second recesses  382   a ,  382   b  can extend completely through the body  378  such that the flow of liquid material L can flow through the passages  331 ,  361  of one of the first and second die plates  325 ,  350  when the first and second die plates  325 ,  350  are disposed within the first and second recesses  382   a ,  382   b . Further, each of the heating cartridges  388  can extend through the frame  375  and at least partially into one of the first and second die plates  325 ,  350 , such that the plurality of heating cartridges  388  are configured to heat the frame  375  as well as the first and second die plates  325 ,  350 . 
     The one of the first and second die plates  325 ,  350  that is in fluid communication with the diverter valve  314  and the pelletizer  400  during a pelletizing operation can be configured to couple the frame  375  and the first and second die plates  325 ,  350  to the diverter valve  314 . Specifically, the first die plate  325  can define a plurality of bores  396   a  that are each configured to receive a fastener  398  so as to couple the frame  375  and the first die plate  325  to the diverter valve  314 . Similarly, the second die plate  350  can define a plurality of bores  396   b  that are each configured to receive a fastener  398  so as to couple the frame  375  and the second die plate  350  to the diverter valve  314 . The fasteners  398  can be bolts, or any other type of conventional fastener capable of releasably coupling the first and second die plates  325 ,  350  to the diverter valve  314 . Further, though a certain number and configuration of bores  396   a ,  396   b  are depicted, the bores  396   a ,  396   b  can be otherwise design and/or arranged as desired. 
     Like the pelletizing system  10 , during operation of the pelletizing system  310 , only one of the first and second die plates  325 ,  350  is in fluid communication with the diverter valve  314  and the pelletizer  400 . In previous pelleting systems, the system would have to be disassembled in order to service and/or replace a die plate. In the pelletizing system  310 , the die plate changing system  370  can easily transition between positioning the first die plate  325  and the second die plate  350  in fluid communication with other aspects of the pelletizing system  310 . To do this, the die plate changing system  370  can include a movement assembly  430  operably coupled to the frame  375  and configured to selectively move the frame  375  between multiple positions. For example, the movement assembly  430  can be configured to move the frame  375  between a first position, where the first die plate  325  is configured to receive the liquid material from the diverter valve  314 , and a second position, where the second die plate  350  is configured to receive the material from the diverter valve  314 . The first position is explicitly shown in  FIGS. 6A-8 . 
     The movement assembly  430  of the pelletizing system  310  is configured to rotate the frame  375  between the first and second positions. To do this, the movement assembly  430  can comprise a support structure  438  and a pivot  434  coupled to the frame  375  and the support structure  438 . The support structure  438  is depicted as a metal beam, though other types of support structures  438  are contemplated. The pivot  434  can be configured to extend through a pivot bore  399  defined by the frame  375  so as to selectively rotate the frame between the first and second positions. The pivot  434  can be configured to rotate the frame  375  about an axis that is substantially parallel to the longitudinal direction  2 , though other orientations for this axis are contemplated. In one embodiment, the frame  375  is configured to be manually transitioned between the first and second positions. However, it is also contemplated that the die plate changing system  370  can include automated means for transitioning the frame  375  between the first and second positions, such as a motor. 
     Now referring to  FIG. 9 , a method of changing die plates  25 ,  50 ,  325 ,  350  in a pelletizing system  10 ,  310  will be described. The method  900  begins with step  904 , which includes heating a first die plate  25 ,  325  within a frame  75 ,  375 . Heating the first die plate  25  in step  904  can comprise providing a heated liquid to the first die plate  25 . Alternatively, heating the first die plate  325  in step  904  can comprise powering the heating cartridges  388 . After step  904 , in step  908  the material is provided to the first die plate  25 ,  325  from a diverter valve  14 ,  314  when the frame  75 ,  375  is in a first position. Then, in step  912 , the second die plate  50 ,  350  is heated within the frame  75 ,  375 . After step  912 , step  916  involves moving the frame  75 ,  375  from the first position to a second position. In one embodiment, moving the frame  75  comprises linearly translating the frame from the first position to the second position. Moving the frame  75 ,  375  in step  916  can be performed manually. Alternatively, moving the frame  75  in step  916  can be performed automatically using a motor  212 . Further, moving the frame  375  can comprise rotating the frame  375  from the first position to the second position. Then step  920  is performed, which includes providing the material to the second die plate  50 ,  350 . Step  920  can comprise providing the heated liquid to the second die plate  50 . Alternatively, step  920  can comprise powering the plurality of heating cartridges  388 . 
     While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts, and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features, and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts, and features that are fully described herein without being expressly identified as such or as part of a specific invention, the scope of the inventions instead being set forth in the appended claims or the claims of related or continuing applications. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated. While the invention is described herein using a limited number of embodiments, these specific embodiments are not intended to limit the scope of the invention as otherwise described and claimed herein. The precise arrangement of various elements and order of the steps of articles and methods described herein are not to be considered limiting.