Patent Publication Number: US-11655590-B1

Title: Through-air apparatus with cooling system

Description:
FIELD OF THE INVENTION 
     The invention relates, in part, to a through-air apparatus for manufacturing web products, where the through-air apparatus includes a system to cool the web. 
     BACKGROUND 
     “Through air technology” is a term used to describe systems and methods enabling the flow of air through a paper or nonwoven web for the purpose of drying or bonding fibers or filaments. Examples include the drying of nonwoven products (e.g., tea bags and specialty papers); drying and curing of fiberglass mat, filter paper, and resin-treated nonwovens; thermobonding and drying of spunbond nonwovens; drying hydroentangled webs; thermobonding geotextiles with or without bicomponent fibers; drying and curing interlining grades; and thermobonding absorbent cores with fusible binder fibers. The drying of tissue paper is also another application of through air technology. 
     Systems and methods related to through-air drying are commonly referred to through the use of the “TAD” acronym. Systems and methods related to through-air bonding are commonly referred to through the use of the “TAB” acronym. 
     A through-air apparatus generally includes a rigid air-permeable web-carrying structure, typically called a through-air roll. A web is placed on the through-air roll, and as the through-air roll rotates, a fan may blow air through the wall of the through-air roll to treat the web. The through-air roll typically has a plurality of openings to permit the air to pass through the roll. 
     SUMMARY OF THE INVENTION 
     According to one embodiment, a through-air apparatus for drying, curing, or bonding paper or non-woven products is provided. The apparatus includes a through-air roll configured for rotational movement about a first axis, and the through-air roll is configured to carry a web. The apparatus also includes a hood at least partially enclosing the through-air roll, and a cooling system positioned adjacent the through-air roll. The cooling system is configured to provide cool air to a web as the web leaves the through-air roll, and all of the cooling system is external to the through-air roll. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of a prior art through-air apparatus; 
         FIG.  2    is a schematic diagram of a through-air apparatus according to one embodiment which illustrates a carrying wire; 
         FIG.  3    is a schematic diagram of a through-air apparatus according to another embodiment which illustrates a carrying wire and a supply duct system; 
         FIG.  4    is a schematic diagram of a through-air apparatus according to another embodiment; 
         FIG.  5    is a schematic diagram of a through-air apparatus according to yet another embodiment which illustrates a restraining wire; 
         FIG.  6    is a schematic diagram of a though-air apparatus according to one embodiment which illustrates a carrying wire and a restraining wire; 
         FIG.  7    is a schematic diagram of a though-air apparatus according to yet another embodiment in which the cool air flow through the cooling system is in the opposite direction from the earlier described embodiments; and 
         FIG.  8    is a perspective view of a portion of a through-air apparatus according to yet another embodiment that illustrates a cross beam exhaust header. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed to a through-air apparatus configured to manufacture various products, such as paper/tissue and/or nonwoven webs. The through-air apparatus may be configured for drying, curing, or bonding, and one of ordinary skill in the art would recognize that the through-air apparatus may be configured as a through-air dryer (TAD) and/or a through-air bonder (TAB), depending on the context in which the apparatus is used. One of ordinary skill in the art will also recognize that the through-air apparatus may be used to make various web products that are rolled in their finished end product form. It should also be recognized that the product may not be rolled and/or may be cut into a finished end product. Furthermore, one of ordinary skill in the art will also recognize that the through-air apparatus may be configured to make various products, including, but not limited to various films, fabric, or other web type material, and the apparatus may be used for various processes that may include mass transfer, heat transfer, material displacement, web handling, and quality monitoring, including, but not limited to drying, thermal bonding, sheet transfer, water extraction, web tensioning, and porosity measurement. 
     As set forth in more detail below, the through-air apparatus includes a through-air roll configured to rotate relative to another portion of the apparatus. A web is placed on the through-air roll, and as the web rotates, a fan may blow air through the wall of the through-air roll to treat the web. The through-air roll typically has a plurality of openings to permit the air to pass through the roll. 
     In one embodiment, a web (i.e. product) is typically in a sheet-form and is partially wrapped around the cylindrical outer surface/shell of the through-air roll. The web is wrapped about a portion of the roll ranging from, for example, 90° to 360°, and typically between 180°-300° around the roll. The cylindrical wall of the through-air roll typically has a plurality of openings configured for air to pass through. A fan/blower may be used to circulate the air across the product, and the through-air roll is typically positioned within a hood to optimize the air flow characteristics. As the product travels with the rotating shell through the active zone of the apparatus, the fan/blower circulates air through the wall of the cylindrical shell to treat the product. A heater may be provided so that heated air circulates through the through-air roll. 
       FIG.  1    illustrates a portion of a conventional prior art through-air apparatus  100 . As shown, the through-air apparatus  100  includes a though-air roll  120  that is configured to rotate about a first axis  130 . The roll  120  is configured to carry a web  10 . In this embodiment, the roll  120  and web  10  rotate in a clockwise direction about the first axis  130 . As shown, a carrying wire  20  may be configured to extend around at least a portion of the through-air roll  120  to carry the web  10 . Also, a hood  110  at least partially encloses the through-air roll  120 . 
     As shown in  FIG.  1   , the conventional through-air apparatus  100  includes a cooling system  50  that is configured to cool the web  10  as the web leaves the through-air roll  120 . A cooling system  50  may be used to set the fiber bonds within the web  10 . It is generally desirable to cool the web  10  as soon as the bonds have been formed and as close to the detachment point  124  (i.e. tangent point) where the web leaves the through-air roll  120 . A cooling system  50  may also be used for a clean separation of the web  10  from the carrying wire  20 . 
     In this prior art apparatus  100 , the cooling system  50  includes a first duct component  52  adjacent the through-air roll  120  and a second duct component  54  inside of the through-air roll  120 . As shown by the arrows that represent cool air flow through the cooling system in  FIG.  1   , the conventional cooling system  50  is configured so that cool air passes through the web  10  and into the first duct component  52 , and across the rotating through-air roll  120  and into the second duct component  54  towards the first axis  130  of the through-air roll  120 . The arrows that represent cool air are depicted without one or more channels or nozzles to localize the region of cooling on the web.  FIG.  1    depicts ambient cooling air simply being draw by negative pressure from the environment in which the system is assembled, through the web and the downstream ducting. One of skill in the art will recognize that one or more channels and/or nozzles may be provided which are useful for focusing the incoming cooling air, in the area of the arrows in  FIG.  1   , for the purpose of optimizing the process. As shown, the cooling system  50  may also include a third duct component  56  that extends inside of the through-air roll  120  along the first axis  130  (i.e. axis of rotation of the roll  120 ). It should be appreciated that the second and third duct components  54 ,  56  may be part of a stationary baffle system inside of the through-air roll  120 . Prior art embodiments in which cooling air passes through the web may have ducting systems internal to the through-air roll differing from those described herein. 
     The Applicant recognized problems associated with the conventional through-air apparatus  100  shown in  FIG.  1   . In particular, the inventor recognized that with the conventional cooling system shown in  FIG.  1   , it was difficult and time consuming to access the components of the cooling system that were inside of the through-air roll. As mentioned above, the second and third duct components  54 ,  56  are positioned inside of the through-air roll  120 . Conventional cooling systems  50 , such as the one shown in  FIG.  1   , typically require frequent cleaning, seal adjustments and other general maintenance of the components inside of the through-air roll  120 . However, it may be difficult to access these confined spaces in the interior of the through-air roll  120 . As set forth in more detail below, aspects of the present disclosure are directed to a new cooling system where all of the cooling system is external to the through-air apparatus. 
     The Applicant contemplated that the present disclosure may have a variety of advantages. First, a configuration where all of the cooling system is external to the through-air roll  120  enables all of the components of the cooling system to be more easily accessed for cleaning and maintenance, as entering the through-air roll is not required. Second, a configuration where all of the cooling system is external to the through-air roll  120  may also improve the energy efficiency of the through-air apparatus. In particular, by separating all of the components of the cooling system away from the inside of the through-air roll (and the hot process air) the overall energy efficiency of the apparatus may be improved, as the cool air is less likely to mix with the warmer process air (and vice versa). 
     Turning now to  FIG.  2   , one embodiment of a through-air apparatus  200  according to the present disclosure will now be described. The through-air apparatus  200  shown in  FIG.  2    has a cooling system  300  that is external to the through-air roll  120 . In other words, unlike the conventional cooling system  50  shown in  FIG.  1   , none of the components of the cooling system  300  are positioned inside of the through-air roll  120 . Further details regarding the cooling system  300  are discussed below. 
     The through-air apparatus  200  shown in  FIG.  2    has a through-air roll  120  which is configured to rotate about a first axis  130 . A through-air apparatus  200  is typically a very large machine. For example, the through-air roll  120  may have an axial length ranging from 1 foot—30 feet, and a diameter ranging from 1 foot—25 feet. The cylindrical wall of the roll  120  may be formed of an open rigid structure to permit the flow of air therethrough. In one embodiment, the through-air roll  120  may be a HONEYCOMB ROLL® obtained from Valmet, Inc. 
     As shown, a hood  110  at least partially encloses the through-air roll  120 . One of ordinary skill in the art will appreciate that in one embodiment, the hood  110  is configured to fully enclose the through-air roll  120 . In another embodiment, the hood  110  is configured to only partially enclose the through-air roll  120 , as the disclosure is not limited in this respect. In one embodiment, it is contemplated that the hood may enclose from about 20° around the through-air roll  120  up to about 360° around the through-air roll  120 . Furthermore, one of ordinary skill in the art will also appreciate that the through-air roll  120  and the hood  110  are typical components of a through-air apparatus and thus are not discussed in great detail. 
     As shown in  FIG.  2   , a web  10  is wrapped around the roll  120 . One or more idler rolls  12  may be provided to transfer a web  10  off of the through-air roll  120 . In this particular embodiment, the cooling system  300  is positioned between the through-air roll  120  and the idler roll  12 . 
     The cooling system  300  may include one or more of the following components. First, as shown in  FIG.  2   , the cooling system  300  includes a wedge-shaped duct component  310 . As shown, the wedge-shaped duct component  310  is adjacent the through-air roll  120  and is also external to the through-air roll  120 . As shown, the shape of the wedge-shaped duct component  310  may substantially follow the radius of curvature of the through-air roll  120 , so that it can be positioned at the tangent point where the web  10  separates from the roll  120 . As shown in  FIG.  2   , the cooling system  300  may also include an exhaust duct system  320 ,  350  which is external to the through-air roll  120 . In one illustrative embodiment, the exhaust duct system  320 ,  350  is downstream of the wedge-shaped duct component  310 . As shown, one or more dampers  340  may be provided inside of the cooling system  300  to control the flow of the cool air. In one embodiment, one damper  340  may be used to control the overall flow rate of the cool air. In another embodiment, a plurality of dampers  340  may be used to control the flow profile of the cool air. Further embodiments illustrating various air flow control dampers are also set forth in more detail below. 
     As shown by the representative cool air flow path arrows in  FIG.  2   , in one illustrative embodiment, cool air may pass up through the web  10  to cool the web  10  as it leaves the through-air roll  120 . After the cool air passes through the web  10 , the cool air enters into the wedge-shaped duct component  310 . It should be appreciated that the bottom surface of the wedge-shaped duct component  310  has one or more openings to permit the passage of air therethrough. From the wedge-shaped duct component  310 , the cool air may enter the exhaust duct system  320 ,  350 . After the cool air passes through the exhaust duct system  320 ,  350  it may be vented to atmosphere. 
     As mentioned above, the apparatus  200  may include one or more idler rolls  12  which may assist in transfer of the web  10  onto and off of the roll  120 . As shown in  FIG.  2   , the apparatus  200  may also include an idler roll  22  which may assist in the transfer of a carrying wire  20  onto and off of the roll  120 . The idler rolls  12 ,  22  may or may not be driven by a motor, chain, or other mechanism. As shown, a carrying wire  20  may be configured to extend around at least a portion of the through-air roll  120  to carry the web  10 . The carrying wire  20  acts as a support structure for the web  10 , and as shown in  FIG.  2   , the carrying wire  20  is positioned between the through-air roll  120  and the web  10 . As shown in  FIG.  2   , in one illustrative embodiment, the cooling system  300  is configured to provide cool air to the web  10  while the web  10  is still in contact with the carrying wire  20 . The idler rolls  12 ,  22  may be positioned to separate the web  10  from the carrying wire  20  just after the cooling system  300  provides cool air to the web  10 . 
     The specific embodiment disclosed in  FIG.  2    illustrates a configuration which includes at least one blocking plate configured to prevent cool air from entering the through-air roll  120 . For example, in one illustrative embodiment, the wedge shaped duct component  310  includes a blocking plate  312 , and the through-air roll  120  may also include a blocking plate  122 . As shown, the one or more blocking plates  312 ,  122  may be curved pieces that match the contour of the through-air roll  120 . In another embodiment, the blocking plates  312 ,  122  may have a different contour and may also be flat. In the embodiment illustrated in  FIG.  2   , the blocking plate  312  on the wedge-shaped duct component  310  prevents the cool air that passes into the duct component  310  from passing into the through-air roll  120 . In this embodiment, the blocking plate  312  is also configured to direct the cool air up into the exhaust duct system  320 ,  350 . In one embodiment, the blocking plate  122  inside of the through-air roll  120  may be part of a stationary baffle system inside of the through-air roll  120 . 
     As mentioned above, the cooling system  300  is configured to provide cool air to a web  10  as the web  10  leaves the through-air roll  120 . The “cool air” may be defined as air that has a temperature that is lower than the drying/curing/bonding process air temperature within the through-air apparatus. In one embodiment, the temperature of the cool air may range from about 40° F. to about 300° F. In another embodiment, the temperature of the cool air may range from about 55° F. to about 80° F. 
     The cool air may be sourced from a variety of locations. As shown in  FIG.  2   , the cool air may be sourced from the air surrounding the through-air apparatus  200 . The present disclosure also contemplates that the cool air may be sourced from an external source, including but not limited to air that is sourced from the outside, a chilled unit, a machine hall, and/or a moist air source. In one embodiment, the cool air may be sourced from system air from another portion of the through-air apparatus system. In one embodiment, the cool air is sourced from the exhaust line of the through-air apparatus. In one embodiment, the cool air is chilled to a temperature below room temperature (i.e. between about 60-80° F.). 
     As shown in  FIG.  2   , in one embodiment, the cooling system  300  includes a perforated plate cartridge  330  which is external to the through-air roll  120 . The perforated plate cartridge  330  may be configured to adjust the air flow across the web for substantially uniform cooling. In one embodiment, the plate cartridge  330  is removable from the cooling system  300  for cleaning and maintenance. In one embodiment, the plate cartridge  330  slides in and out of the exhaust duct system  320 . 
       FIG.  3    illustrates another embodiment of a through-air apparatus  202  according to the present disclosure.  FIG.  3    is similar to the above-described through-air apparatus  200  shown in  FIG.  2   . Accordingly, similar components have been given identical reference numbers. Unlike  FIG.  2   , in which the cooling system  300  sources the cool air from the surrounding environment, in  FIG.  3   , the cooling system  300  further includes a supply duct system  360 , which is also external to the through-air roll  120 . As shown, the supply duct system  360  may include one or more dampers  370  to control the flow of the cool air through the cooling system  300 . As shown in  FIG.  3    by the cool air flow path arrows, in one embodiment, cool air may pass from the supply duct system  360  and through the web  10  to cool the web  10  as it leaves the through-air roll  120 . As shown, after the cool air passes through the web  10 , the cool air enters into the wedge-shaped duct component  310 . From the wedge-shaped duct component  310 , the cool air may then enter the exhaust duct system  320 ,  350 . 
     It is also contemplated that in any of the embodiments described herein, one or more of the cooling system duct component  310 ,  320 ,  330 ,  350 ,  360  may include one or more seals to capture the cool air flow into the desired plenums. In one embodiment, the one or more seals may be mechanical seals, and in another embodiment for example, seals provided by an air knife, air curtain, or a stream of air are also contemplated. 
     As shown in  FIG.  3   , in one illustrative embodiment, the cooling system  300  is configured to provide cool air to the web  10  while the web  10  is still in contact with the carrying wire  20 . The idler rolls  12 ,  22  may be positioned to separate the web  10  from the carrying wire  20  just after the cooling system  300  provides cool air to the web  10 . As mentioned above, the cool air in the supply duct system  360  may be sourced from the outside, a chilled unit, a machine hall, and/or a moist air source. It should also be recognized that any of the embodiments described herein may include a supply duct system  360  as shown in  FIG.  3   . 
       FIG.  4    illustrates yet another embodiment of a through-air apparatus  204  according to the present disclosure.  FIG.  4    is similar to the above-described through-air apparatus  200  shown in  FIG.  2   . Accordingly, similar components have been given identical reference numbers. Unlike  FIG.  2   , the through-air apparatus  204  shown in  FIG.  4    does not include a carrying wire  20  or idler roll  22 . Instead, the web  10  is in direct contact with the through-air roll  120 . Optionally in this configuration, the roll  120  may be covered with a wire sleeve, as one of ordinary skill in the art would recognize. Thus, as the web  10  separates from the roll  120 , the cooling system  300  is configured to provide cool air directly through the web (and not also through a carrying wire  20 ). As shown in  FIG.  4    by the cool air flow path arrows, in one embodiment, cool air may pass from the surrounding environment and through the web  10  to cool the web as it leaves the through-air roll  120 . After the cool air passes through the web  10 , the cool air enters into the wedge-shaped duct component  310  and then through the exhaust duct system  320 ,  350  as described above. 
       FIG.  5    illustrates yet another embodiment of a through-air apparatus  206  according to the present disclosure.  FIG.  5    is also similar to the above-described through-air apparatus  200  shown in  FIG.  2   . Accordingly, similar components have been given identical reference numbers. Unlike  FIG.  2   , the through-air apparatus  206  shown in  FIG.  5    does not include a carrying wire  20  or idler roll  22 . Instead, the through-air apparatus  206  includes a restraining wire  30  which is configured to extend around at least a portion of the through-air roll  120  and over the web  10  to restrain the web  10 . As shown, the web  10  is positioned between the through-air roll  120  and the restraining wire  30 . Optionally in this configuration, the roll  120  may be covered with a wire sleeve, as one of ordinary skill in the art would recognize. In one illustrative embodiment, the through-air apparatus  206  may also include one or more idler rolls  32  which may assist in the transfer of the restraining wire  30  onto and off of the roll  120 . As shown in  FIG.  5   , in one illustrative embodiment, the cooling system  300  is configured to provide cool air to the web  10  while the web  10  is still in contact with the restraining wire  30 . The idler rolls  12 ,  32  may be positioned to separate the web  10  from the restraining wire  30  just after the cooling system  300  provides cool air to the web  10 . After the cool air passes through the web  10 , the cool air enters into the wedge-shaped duct component  310 . From the wedge-shaped duct component  310 , the cool air may then enter the exhaust duct system  320 ,  350 . 
       FIG.  6    illustrates another embodiment of a through-air apparatus  208  according to the present disclosure.  FIG.  6    is also similar to the above-described through-air apparatus shown in  FIGS.  2 - 5   . Accordingly, similar components have been given identical reference numbers. However, the through-air apparatus  208  shown in  FIG.  6    includes both a carrying wire  20  and a restraining wire  30 . As shown, the web  10  is positioned between the carrying wire  20  and the restraining wire  30 , and the cooling system  300  is configured to provide cool air to the web  10  while the web  10  is in contact with both the carrying wire  20  and the restraining wire  30 . 
     As shown in  FIG.  6    by the cool air flow path arrows, in one embodiment, cool air may pass from the surrounding environment and through the restraining wire  30 , web  10 , and carrying wire  20  to cool the web  10  as it leaves the through-air roll  120 . It should also be recognized that in one embodiment, the embodiment shown in  FIG.  6    may also include a supply duct system  360 . After the cool air passes through the web  10 , the cool air enters into the wedge-shaped duct component  310 . From the wedge-shaped duct component  310 , the cool air may then enter the exhaust duct system  320 ,  350 . 
     In one illustrative embodiment, the cooling system  300  includes a fan  380  configured to direct cool air onto the web or pull cool air through the web  10  as the web  10  leaves the through-air roll  120 . As shown in  FIG.  6   , in one embodiment, the fan  380  is positioned within the exhaust duct system  320 ,  350 . One of ordinary skill in the art will appreciate that in another embodiment, one or more fans  380  may be positioned in different locations within the cooling system  300  to cause the cool air to move desirably through the cooling system  300  and also across the web  10 . For example, in one embodiment that includes a supply duct system  360 , such as the embodiments shown in  FIGS.  3  and  7   , a fan (not shown) may be positioned in the supply duct system  360 . Also, in one embodiment, the fan speed may be adjusted to control the cool air flow through the cooling system  300 . 
     Furthermore, the embodiment shown in  FIGS.  2 - 6    all illustrate configurations where the cool air flows in the same upward direction. The present disclosure also contemplates other cool air flow paths as the disclosure is not limited in this respect. For example,  FIG.  7    illustrates an embodiment with a different cool air flow path. In  FIG.  7   , the through-air apparatus  210  is similar to the above-described embodiments. Accordingly, similar components have been given identical reference numbers. However, in the through-air apparatus  210  shown in  FIG.  7   , the cool air flow path is in the opposite downward direction. In this configuration the duct systems  320 ,  350  act as the supply duct system and the duct system  360  acts as the exhaust duct system, as the disclosure is not so limited. As shown, the cool air flows through the supply duct system (duct systems  320 ,  350 ) and also in the opposite direction through the wedge-shaped duct component  310  to provide cool air to the web  10  as the web leaves the through-air roll  120 . After the cool air passes through the web  10 , the cool air enters into the exhaust duct component  360 . From there, the cool air may then continue through additional exhaust duct systems and it may be vented to atmosphere. As shown, the cooling system  300  includes one or more air flow control dampers  340 ,  370  to control the flow of cool air or the uniformity of air flow through the cooling system  300 . In this air flow arrangement illustrated in  FIG.  7   , a restraining wire  30  and a carrying wire  20  are both shown. It is also contemplated that in another embodiment, the web  10  may be carried on the through-air roll  120  without the restraining wire  30  and/or the carrying wire  20 , as the disclosure is not so limited. Optionally, the roll  120  may be covered with a wire sleeve, as one of ordinary skill in the art would recognize 
       FIG.  8    illustrates yet another embodiment of a through-air apparatus  212 . In some respects, the through-air apparatus  212  is similar to the above-described embodiments. Accordingly, similar components have been given identical reference numbers. As shown, the cooling system  300  includes a wedge-shaped duct component  310 . For simplicity, the through-air roll  120  is not included in  FIG.  8   . However, one of ordinary skill in the art would appreciate that in one embodiment, the through-air roll  120  would be positioned adjacent to and in front of the wedge-shaped duct component  310 . In this particular illustrative embodiment, the cooling system  300  includes an exhaust duct system  350  which is configured as a cross beam exhaust header. In one embodiment, the cross beam exhaust header has a length L, and each end of the cross beam exhaust header may be coupled to vertical support columns on the through-air apparatus. In one embodiment, a through-air roll has a first end and second end, and the cross beam exhaust header length L may extend from the first end of the through-air roll to its second end, thus the cooling system  300  extends the length of the through-air roll. As shown in  FIG.  8   , in one embodiment, the cooling system  300  includes a plurality of dampers  340  spaced apart across the length of the cross beam exhaust header  350 . As mentioned above, the dampers  340  may be provided to control the flow, or uniformity of flow across the machine, of the cool air through the cooling system  300 .  FIG.  8    also illustrates another view of the perforated plate cartridge  330  which may be configured to adjust the air flow across the web for substantially uniform cooling and may also be removable from the cooling system  300  for cleaning and maintenance. 
     It is contemplated that the above-described concepts can be incorporated into a new through-air apparatus. The inventor also contemplated that these above-described concepts can be retrofitted onto an existing through-air apparatus. In other words, one could retrofit an existing through-air apparatus, such as the one shown in  FIG.  1   , and alter it so that it has a cooling system  300  that is external to the through-air roll  120 , as shown in the embodiments illustrated in  FIGS.  2 - 8   . 
     Although several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto; the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and/or methods, if such features, systems, articles, materials, and/or methods are not mutually inconsistent, is included within the scope of the present invention. 
     All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. 
     The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” 
     The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified, unless clearly indicated to the contrary. 
     All references, patents and patent applications and publications that are cited or referred to in this application are incorporated in their entirety herein by reference.