Abstract:
A grain dryer has a grain column configured to receive grain to be dried and ducts extending from a first wall of the grain column to a second wall of the grain column. The grain dryer is configured so that different numbers of the ducts are selectable for handling cooling air used for cooling the grain.

Description:
FIELD 
     The present disclosure relates generally to grain dryers, and, in particular, the present disclosure relates to grain dryers configured so that different numbers of ducts in a grain column are selectable for cooling. 
     BACKGROUND 
     Duct-type grain dryers (e.g., sometimes called mixed-flow grain dryers) typically do not have any screens that can plug or that may need to be cleaned. This can reduce the need for maintenance and may allow a wide variety of different grains to be dried. 
     In duct-type grain dryers, grain may flow downward under the influence of gravity, e.g., through a grain column containing a plurality of ducts. The grain may be dried by passing heated air through the grain as the grain flows downward through the grain column. In some duct-type grain dryers, some of the ducts in the grain column might direct the heated air into contact with the downward flowing grain. The heated air may then flow through the downward flowing grain and may be subsequently cooled by the grain. The cooled air may then be directed from the grain column by other ducts in the grain column. 
     In some applications, after heated drying, the grain might be cooled before the grain exits the grain dryer, e.g., to prevent deterioration during storage. Some duct-type grain dryers, for example, might use pressurized air cooling in their grain columns. For example, ducts might be used to direct the pressurized cooling air into the grain. However, pressurized cooling can result in undesirable heat loss and energy consumption. 
     For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternatives to existing cooling systems for duct-type grain dryers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cutaway end view of an example of an interior of a grain dryer. 
         FIG. 2  is an enlarged view of region  185  in  FIG. 1 . 
         FIG. 3  is a view taken along the lines  3 - 3  in  FIG. 2 . 
         FIG. 4  illustrates cooling air flows and heating air flows in an enlarged view of a portion of the left side of  FIG. 1 . 
         FIG. 5  is a plan view of an example of an adjustable intake assembly as viewed along line  5 - 5  in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, specific embodiments. In the drawings, like numerals describe substantially similar components throughout the several views. Other embodiments may be utilized and structural and mechanical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense. 
       FIG. 1  is a cutaway end view of an interior of a duct-type grain dryer  100 .  FIG. 2  is an enlarged view of region  185  in  FIG. 1 . For some embodiments, grain dryer  100  might not have any screens, e.g., grain dryer  100  might be screenless. 
     Grain dryer  100  may include a duct (e.g., a plenum)  110 , that may be vertical, between ducts (e.g., grain columns)  115  that might be identical to each other and that might be vertical. Grain (e.g., “wet” grain) to be dried may be received in grain columns  115  from a garner bin  118 . The grain might be gravity fed downward through grain columns  115  into metering sections  120  that may respectively include motor-driven metering rolls  122 , as shown in  FIG. 2 . The rotational speed of metering rolls might control the rate at which the grain flows through each of grain columns  115 . For example, the higher the rotational speed of the metering rolls; the higher the rate at which the grain flows through grain columns  115 . Metering sections  120  respectively direct the grain onto conveyers  125 . 
     It should be recognized the term vertical takes into account variations from “exactly” vertical due to routine manufacturing and/or assembly variations and that one of ordinary skill in the art would know what is meant by the term vertical. 
     A burner  127  may be located in the interior of grain dryer  100 , below duct  110  and between the respective grain columns  115 . A motor-driven blower (e.g., fan)  130 , such as an axial blower, may be located in the interior of grain dryer  100 , below burner  127  and between the respective grain columns  115 . Operation of blower  130  may cause an inlet  132  (e.g., the suction side) of blower  130  and a region  135  (e.g., that might be referred to as a tub) of grain dryer  100  that is below blower  130  and fluidly coupled to inlet  132  to be at vacuum pressure, e.g., below the atmospheric pressure of the outside air external to grain dryer  100 . Blower  130  directs air through burner  127  that is fluidly coupled to an outlet (e.g., the pressure side) of blower  130 . Burner  127  subsequently heats the air for drying the grain in grain columns  115 . 
     As used herein “fluidly coupled” means to allow the flow of fluid (e.g., air). For example, air is allowed to flow between fluidly coupled elements, i.e., from one of the fluidly coupled elements to the other. For selectively fluidly coupled elements, air flows from one of the elements to the other in response to an action, such as the opening of a damper between the elements. That is, when one or more dampers are between two elements, the two elements are selectively fluidly coupled to each other, for example. When ducts are fluidly coupled to a region or element, the flow passages within these ducts are fluidly coupled to the region or element, for example. 
     Each of grain columns  115  might be between duct  110  and a respective duct (e.g., air cavity)  137  that opens to and that is fluidly coupled, through openings  138 , to the outside air (e.g., atmospheric air) that is external to and that surrounds grain dryer  100 . For example, air cavities  137  might be at the pressure of the outside air. 
     Each air cavity  137  might between a respective heat shield  139  and a respective one of grain columns  115 . That is, the respective heat shield  139  might form at least a portion of an exterior shell of grain dryer  100 , for example. For example, an exterior surface of heat shield  139  might be in contact with the outside air that is external to and that surrounds grain dryer  100 . That is, for example, each heat shield  139  may be between the outside air and a respective air cavity  137 . Heat shields  139  might be made from galvanized steel, for example. 
     Each of the grain columns  115  includes a plurality of ducts (e.g., channels)  140  and a plurality of ducts (e.g., channels)  142 . For example, each of ducts  140  and  142  may be between duct  110  and an air cavity  137 . Ducts  140  and  142  might alternate along the lengths of grain columns  115  so that a respective duct  142  is at a vertical elevation between the vertical elevations of successively adjacent ducts  140 . That is, for example, respective ones of ducts  142  might be between successively adjacent ducts  140 . 
     Each of ducts  140  might open into duct  110 . For example, each duct  140  might have an inlet/outlet  144  at one of its ends, such as an end  150  ( FIG. 2 ), that opens into duct  110 , e.g., though a wall  152  of a respective grain column  115  adjacent to duct  110 , as shown in  FIG. 2 . An opposite end of that duct  144 , such as an end  154 , might be closed by a portion of a wall  155  of the respective grain column  115  adjacent to a respective air cavity  137 , as shown in  FIG. 2 . 
     For example, ducts  140  might be horizontal and might span the entire distance between walls  152  and  155  of a grain column  115 . Ducts  140  might be transverse (e.g., perpendicular to within routine manufacturing and/or assembly variations) to the direction of the grain flow in grain columns  115 , for example. 
     It should be recognized that the term horizontal takes into account variations from “exactly” horizontal due to routine manufacturing and/or assembly variations and that one of ordinary skill in the art would know what is meant by the term horizontal. It should be recognized that vertical and horizontal are perpendicular to each other to within routine manufacturing and/or assembly variations. 
     Each of ducts  142  might open into a respective air cavity  137 . For example, each duct  142  might have inlet/outlet  158  at one of its ends, such as an end  160  ( FIG. 2 ), that opens into a respective air cavity  137 , e.g., though a respective wall  155 , as shown in  FIG. 2 . An opposite end of that duct  142 , such as an end  162 , might be closed by a portion of a respective wall  152 , as shown in  FIG. 2 . 
     For example, ducts  142  might be horizontal and might span the entire distance between walls  152  and  155  of a grain column  115 . Ducts  142  might be transverse (e.g., perpendicular) to the direction of the grain flow in grain columns  115 , for example. 
     A lower portion of duct  110  might include an outer duct (e.g., channel)  175  on either side of an inner duct (e.g., channel)  180 , as shown in  FIGS. 1 and 2 . For example, a wall  182  of a pair of walls  182  might be between a respective one of outer ducts  175  and inner duct  180 . Burner  127  might be located within inner duct  180  between walls  182 , as shown in  FIGS. 1 and 2 . Inner duct  180  is configured to receive pressurized air exiting the pressure side (e.g., the outlet) of blower  130 . Outer ducts  175  and inner duct  180  might be vertical, for example. 
     Each of a plurality of dampers  190 , such as dampers  190   1  to  190   4  ( FIG. 2 ), might be configured to selectively partition each of outer ducts  175  into two regions, e.g., a region above a respective damper and a region below the respective damper. Each of dampers  190   1  to  190   4  might be configured to be selectively opened and closed. For example, each of dampers  190   1  to  190   4  might be configured to be selectively moved from an open position, e.g., as shown for each of dampers  190   1  to  190   3  in  FIG. 2 , to a closed position, e.g., as shown for damper  190   4  in  FIG. 2 . In its closed position, damper  190   4  extends across a respective duct  175  from a respective wall  182  to respective wall  152 . Each of dampers  190   1  to  190   4  may be configured to be selectively pivoted, e.g., about a shaft  192 , between its open and closed positions. 
     When a damper  190  is closed, that damper  190  partitions (e.g., divides) a respective duct  175 , and thus an adjacent grain column  115 , into a region above the closed damper  190  and a region below the closed damper  190 . For example, each of closed dampers  190   4  partitions its respective duct  175  into a region  195  above that closed damper  190   4  and a region  197  below that closed damper  190   4 , e.g., by closing region  195  off from region  197 , as shown in  FIG. 2 . That is, for example, a region in a respective grain column  115  above a closed damper  190   4  might correspond to the region  195  in an adjacent duct  175 , and a region in the respective grain column  115  below that closed damper  190   4  might correspond to the region  197  in the adjacent duct  175 . 
     The region in a grain column  115  above a closed damper  190 , such as closed damper  190   4 , might be subjected to heating, where heating air might flow from the region in the adjacent duct  175  above the closed damper  190 , such as region  195  above closed damper  190   4 , into the region in that grain column  115  above the closed damper  190  through the inlet/outlets  144  of ducts  140  that open into the adjacent duct  175 . The air may then flow from region in the grain column  115  above the closed damper  190  into the adjacent air cavity  137  through inlet/outlets  158 . 
     The region in a grain column  115  below a closed damper  190 , such as closed damper  190   4 , might be subjected to cooling, where cooling air might flow from the adjacent air cavity  137  into the region in that grain column  115  below the closed damper  190  through the inlet/outlets  158  of ducts  142  that open into that air cavity  137 . The air may then flow from region in the grain column  115  below the closed damper  190  into the region in the adjacent duct  175  below the closed damper  190 , such as region  197  below closed damper  190   4 , through inlet/outlets  144 . For example, a closed damper  190  might select region in a grain column  115  above the closed damper  190  for heating and a region in that grain column  115  below the closed damper  190  for cooling. 
     A portion of a grain column  115  might have a plurality zones adjacent to a duct  175  that are defined by the locations of dampers  190 . For example, zone  200   1 , zone  200   2 , and zone  200   3  of a grain column  115  might respectively be between successively adjacent dampers  190   1  and  190   2 , successively adjacent dampers  190   2  and  190   3 , and successively adjacent dampers  190   3  and  190   4 . A zone  200   4  might be between damper  190   4  and a lowermost end (e.g., an outlet)  201  of a duct  175 . A lowermost zone  202  of a grain column  115  might be below the outlet  201  of a duct  175 . 
     When all of dampers  190   1  to  190   4  adjacent to a respective grain column  115  are open, all of the zones  200  of the respective grain column  115  might be subjected to heating, while the lowermost zone  202  is subjected to cooling. For example, lowermost zone  202  might always be subjected to cooling, regardless of the state (e.g., open or closed) of any of dampers  190   1  to  190   4 . 
     Note that the number of the zones  200  of each grain column  115 , and thus the length of each grain column  115  subjected to cooling, may be selectively adjustable using the dampers  190 . For example, selectively closing dampers  190   4  and leaving the remaining dampers  190   1  to  190   3  selects zones  204   4  below closed dampers  190   4  for cooling and the remaining zones  200   1  to  200   3  above closed dampers  190   4  for heating. For example, selectively closing dampers  190   3  and leaving the remaining dampers  190   1 ,  190   2 , and  190   4  open selects zones  200   3  to  200   4  below closed dampers  190   3  for cooling and the remaining zones  200   1  and  200   2  above closed dampers  190   2  for heating. For example, different ones of the plurality of dampers  190  are configured to respectively select different amounts (e.g., a different number of zones  200 ) of the grain columns for cooling. 
       FIG. 3  is a view taken along the lines  3 - 3  in  FIG. 2 , showing the general layout of ducts  140  and  142  in a portion of a representative zone  200  and/or a representative zone  202 . Note, for example, that each of ducts  140  might have an inlet/outlet (e.g. an opening)  310  along its bottom. For example, each duct  140  might be an open channel that faces downward toward the bottom of a respective grain column  115 . An inlet/outlet  310 , for example, might span the entire length of a respective duct  140 , e.g., from wall  152  to wall  155  of a respective grain column  115 . 
     Each of ducts  142 , for example, might have an inlet/outlet (e.g. an opening)  320  along its bottom. For example, each duct  142  might be an open channel that faces downward toward the bottom of a respective grain column  115 . An inlet/outlet  320 , for example, might span the entire length of a respective duct  142 , e.g., from wall  152  to wall  155  of a respective grain column  115 . 
       FIG. 4  illustrates cooling air flows and heating air flows in an enlarged view of a portion of the left side of  FIG. 1 , including the left side of  FIG. 2 . Arrows  405 ,  410 ,  415 ,  420 ,  425 ,  430 ,  435 ,  440 , and  441  represent flows of cooling air, and arrows  450 ,  455 ,  460 ,  465 ,  470 ,  471 ,  472 ,  473 , and  474  represent flows of heating air. 
     In  FIG. 4 , a portion  480  of a respective grain column  115  is selected for cooling in that it is below closed damper  190   3 . For example, closing damper  190   3  selects portion  480  for cooling. For example, portion  480  might include the zones  200   3  and  200   4  shown in  FIG. 2 . Note that zone  200   4  below closed damper  190   4  is selected for cooling in  FIG. 2 . Therefore,  FIGS. 2 and 4  illustrate how closing different dampers (damper  190   4  in  FIG. 2  and damper  190   3  in  FIG. 4 ) respectively selects different portions (e.g., different lengths) of a grain column  115  for cooling, and thus different numbers of ducts  140  and different numbers of ducts  142  for handing cooling air for cooling the grain. For example, a larger number of ducts  140  and ducts  142  are used for handing cooling air in  FIG. 4  when damper  190   3  is closed than in  FIG. 2  when damper  190   2  is closed. Note that each of the grain columns  115  and the respective ducts  175  adjacent to grain columns  115  may be as described below in conjunction with  FIGS. 3 and 4 . 
     Portion  485  is subjected to heating in  FIG. 4  in that it is above closed damper closed damper  190   3 . For example, portion  485  might include the zones  200   1  and  200   2  shown in  FIG. 2 . Note that zones  200   1  to  200   3  above closed damper  190   4  are subjected to heating in  FIG. 2 . Therefore,  FIGS. 2 and 4  illustrate how closing different dampers (damper  190   4  in  FIG. 2  and damper  190   3  in  FIG. 4 ) causes different portions (e.g., different lengths) of a grain column  115  to be subjected to heating. For example, the dampers  190   1  to  190   4  may be respectively configured to selectively close each of the respective the respective ducts  175  at different locations along a length of the respective ducts  175 . 
     In portion  480  of the grain column  115  below closed damper  190   3  in  FIG. 4 , the closed damper  190   3  might cause cooling air to flow into a duct  142  from a respective air cavity  137 , as shown by arrows  410 , through the inlet/outlet  158  of that duct  142  that opens into the air cavity  137  and then to flow into grain column  115  from that duct  140 , as shown by arrows  415 , through the inlet/outlet  320  ( FIG. 3 ) of that duct  142 . The closed damper  190   3  might cause the cooling air to then flow into a duct  140  from grain column  115 , as shown by arrows  420 , through the inlet/outlet  310  ( FIG. 3 ) of that duct  140  and then to flow from that duct  140 , as shown by arrows  405 , into the region  486  of duct  175  (e.g., corresponding to the portion  480  of grain column  115 ) below the closed damper  190   3  through the inlet/outlet  144  of that duct  142  that opens into region  486  of duct  175  below the closed damper  190   3 . The cooling air flowing in the region  486  of duct  175  may then flow from region  486 , as shown by arrows  440 , into the region  135  that is below blower  130  and fluidly coupled to inlet  132  of blower  130 . 
     Grain in the grain column  115  may transfer heat to the cooling air so that the cooling air flowing in a duct  175  is heated. Note that the region  486  of duct  175  might be fluidly coupled to the inlet  132 , e.g., to the suction side, of blower  130 , and the region  486  of duct  175  might be at a lower pressure than air cavity  137  while blower  130  is operating. That is, blower  130  might cause the region  486  of duct  175  to be at vacuum pressure, for example. 
     During cooling of a zone  202  in  FIG. 4 , the cooling air may flow into a duct  142  from air cavity  137 , as shown by an arrow  441 , through the inlet/outlet  158  of that duct  142  and may then flow into grain column  115  from that duct  142 , as shown by arrows  430 , through the inlet/outlet  320  ( FIG. 3 ) of that duct  142 . The cooling air may then flow into a duct  140  from the respective grain column  115 , as shown by arrows  425 , through the inlet/outlet  310  ( FIG. 3 ) of that duct  140  and may then flow from that duct  140  into the region  135 , as shown by arrow  435 , through the inlet/outlet  144  of that duct  140 . 
     Note that the grain in the grain column  115  transfers heat to the cooling air so that the cooling air flowing into region  135  from zone  202  is heated. Also note that zone  202  might be subjected to cooling during the operation of blower  130 , and thus grain dryer  100 , regardless of whether any of the dampers  190  are open or closed. For example, zone  202  might receive cooling air whenever blower  130  is operating. 
     In  FIG. 4 , heating air might flow into a region  488  of duct  175 , as shown by arrows  470 , above closed damper  190   3 , e.g., from the upper portion of duct  110  ( FIG. 1 ). Note that region  488  of duct  175  corresponds to the portion  485  of grain column  115  above closed damper  190   3 . Closed damper  190   3  might cause the heating air flowing in region  488  of duct  175  to flow into a duct  140  from region  488 , as shown by arrows  450 , through the inlet/outlet  144  of that duct  140  and then to flow into grain column  115  from that duct  140 , as shown by arrows  455 , through the inlet/outlet  310  ( FIG. 3 ) of that duct  140 . Closed damper  190   3  might then cause the heating air to flow into a duct  142  from grain column  115 , as shown by arrows  460 , through the inlet/outlet  320  ( FIG. 3 ) of that duct  142  and then to flow from that duct  142  into air cavity  137 , as shown by arrows  465 , through the inlet/outlet  158  of that duct  142 . 
     Note that the region  488  of duct  175  might be fluidly coupled to the outlet, e.g., to the pressure side, of blower  130 , and the region  488  of duct  175  might be at a higher pressure than air cavity  137 , and thus region  486  of duct  175 , while blower  130  is operating. 
     During heating of the upper portion of a grain column  115  above duct  175 , and thus above the zones  200  in  FIG. 2  and above portion  485  in  FIG. 4 , heating air may flow into a duct  140 , as shown by an arrow  471  in  FIG. 4 , from the upper portion of duct  110  through the inlet/outlet  144  of that duct  140  and may then flow into grain column  115  from that duct  140 , as shown by arrows  472 , through the inlet/outlet  310  ( FIG. 3 ) of that duct  140 . The heating air may then flow into a duct  142 , as shown by arrows  473 , from grain column  115  through the inlet/outlet  320  ( FIG. 3 ) of that duct  142  and may then flow from that duct  142  into air cavity  137 , as shown by arrow  474 , through the inlet/outlet  158  of that duct  142 . 
     Note that the portion of a grain column  115  above ducts  175  may be heated regardless of the configuration of dampers  190 . For example, the portion of a grain column  115  above ducts  175  is heated whenever grain dryer  100  is operation (e.g., blower  130  and burner  137  are in operation), regardless of whether dampers  190  are open or closed. Also note that the heating of portion  485  above the closed damper  190   3 , the cooling of portion  480  below the closed damper  190   3 , the cooling of zone  202 , and the heating of the portion of a grain column  115  above ducts  175  may occur concurrently while grain dryer  100  is operating. 
     An adjustable intake assembly  210  might be located below the lowermost ends of grain columns  115 , upstream of inlet  132  of blower  130 . Adjustable intake assembly  210  might be fluidly coupled to the suction side of blower  130 , for example. Adjustable intake assembly  210  might be configured to adjust the amount of outside air that is drawn into grain dryer  100  from the atmosphere external to grain dryer  100 . For example, adjustable intake assembly  210  might be configured to adjust the amount of outside air that enters region  135 . During operation of grain dryer  100 , blower  130  draws the adjusted amount of outside air into region  135 . 
     The outside air might be cooler than the cooling air from the grain columns  115  that enters region  135  from ducts  175  and/or zone  202 . The cooling air from grain columns  115  might mix with the outside air within region  135 . As such, the mixed air might be warmer than the outside air. Blower  130  then causes the warmer mixed air to flow through burner  127 . 
     The warmer mixed air acts to reduce the heating load on burner  127 , thereby reducing the fuel consumption of burner  127  by about 15 to 20 percent and reducing the combined fuel and power consumption by about 30 to 40 percent, e.g., compared to pressurized cooling systems used in conventional duct-type grain dyers that do not recycle cooling air to preheat outside air before the outside air reaches the burner. The warmer mixed air is lighter (e.g., has a lower density) than the outside air. This can reduce the load on, and thus the power consumption of, blower  130 , e.g., compared to pressurized cooling systems used in conventional duct-type grain dyers that do not recycle cooling air to preheat outside air before the outside air reaches the blower. 
     As such, adjustable intake assembly  210  might be configured to adjust the amount of outside air that is mixed with the cooling air from the grain columns  115  that is heated by the grain. For example, adjustable intake assembly  210  may be configured to adjust the amount outside air that enters region  135  through adjustable intake assembly  210  from zero percent of the cooling air that is heated by the grain, in which case adjustable intake assembly  210  does not allow any outside air to enter region  135  directly from adjustable intake assembly  210 , to about 15 to 25 percent of the cooling air that is heated by the grain. 
       FIG. 5  is a plan view of an example of an adjustable intake assembly  210  as viewed along line  5 - 5  in  FIG. 2 . In the example of  FIG. 5 , adjustable intake assembly  210  might include a selectively adjustable door (e.g., that might be referred to as an adjustable outside-air blend door)  510  that might be configured to selectively adjust a size of an inlet  520  to the region  135  of grain dryer  100  that is under blower  130  and between grain columns  115 . 
     For example, door  510  might be configured to selectively move (e.g., slide) over an opening  530  so as to selectively uncover a portion of opening  530  that is inlet  520  and to cover a remaining portion  540  of opening  530 , as shown in  FIG. 5 . That is, for example, selectively sliding door  510  to different locations adjusts the size of inlet  520 . For example, door  510  might be configured to selectively uncover different portions of opening  530 , where the different uncovered portions of the opening  530  may respectively allow different amounts of outside air to be drawn therethrough into region  135 . 
     When door  510  is completely closed, door  510  covers the entire opening  530 , and little or no outside air is drawn directly into region  135  through adjustable intake assembly  210 . Door  510  might be configured to adjust the amount of opening  530 , that is inlet  520 , that is uncovered by door  510  from zero percent of the size of opening  530  when door  510  covers the entire opening  530  to 100 percent of the size of opening  530  when the entire opening  530  is uncovered by door  510 . When the entire opening  530  is uncovered by door  510 , the amount outside air that enters region  135  through adjustable intake assembly  210  might be about 85 percent of the cooling air that gets heated by the grain. 
     Grain dryer  100  might include a scalper drag  198 , as shown in  FIG. 1 . For example, scalper drag  198  might be configured to separate large foreign materials (e.g., larger than the size of the grains) from the grain before the grain enters garner bin  118  and subsequently enters grain columns  115  from garner bin  118 . In one example, scalper drag  198  might include a conveyer that might drag the grain across a screen that allows the grain to pass through its mesh, but not any materials larger than the mesh, and thus the size of the grains. For example, the conveyer might include a plurality of scrapers coupled to a chain that might move in a continuous loop for moving (e.g., dragging) the scrapers over the screen. The scrapers might drag the grain and any larger materials over the screen, where the grain passes through the screen while the scrapers drag the larger materials that do not pass through the screen off the screen. 
     CONCLUSION 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the embodiments will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the embodiments.