Patent Publication Number: US-2010120350-A1

Title: Air knife

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/112,775, entitled “Air Knife,” filed on Nov. 9, 2008, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates generally to fluid discharge devices and, more particularly, to fluid discharge devices configured to deliver a sheet or “blade” of air. Such a device is sometimes referred to as an “air knife.” 
     A variety of systems transfer fluids from a fluid supply source to one or more fluid discharge devices. In some systems, an arrangement of fluid conduits, which may include metal pipes, plastic pipes, and/or hoses, may provide a flow path for routing, channeling, or otherwise delivering a fluid from a fluid supply source to a fluid discharge device, such as an air knife. In the case of an air knife, air received via an inlet may be pressurized and directed through a slot-shaped outlet as a sheet or “blade” of air. The output of the air knife may be utilized for a variety of applications, such as drying and removing moisture from objects, removing dust or debris, cooling, and so forth. 
     BRIEF DESCRIPTION 
     Certain aspects of embodiments disclosed herein by way of example are summarized below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms an invention disclosed and/or claimed herein might take, and that these aspects are not intended to limit the scope of any invention disclosed and/or claimed herein. Indeed, any invention disclosed and/or claimed herein may encompass a variety of aspects that may not be set forth below. 
     Embodiments of an air knife system that includes improved end caps and mounting mechanisms are provided. In one embodiment, a system includes an air knife that includes a main body coupled to first and second end caps having recessed openings. Fasteners may extend through the recessed openings to fasten the first and second end caps to a main body of the air knife. Further, the recessed openings may prevent fasteners from protruding beyond the first end cap and the second end cap, thereby allowing for first and second mounting plates to be secured flush against the first and second end caps, respectively. 
     In a further embodiment, an air knife system includes a mounting system having first and second mounting plates configured to couple to first and second ends, respectively, of the air knife. One of the first or second mounting plates may be secured to the air knife via a first fastener that retains the air knife axially while providing a pivot point for rotational adjustments. A second fastener radially offset from the first fastener is configured to provide for rotational movement of the air knife about the pivot point. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a simplified block diagram depicting a fluid-based system having one or more air knives, in accordance with embodiments of the present disclosure; 
         FIGS. 2-4  are perspective views of an embodiment of an air knife that may be utilized in the system of  FIG. 1 ; 
         FIG. 5  illustrates an embodiment of an end cap that may be secured to an inlet end of a main body of the air knife, as shown in  FIGS. 2-4 ; 
         FIG. 6  illustrates an embodiment of an end cap that may be secured to an adjustment end of a main body of the air knife, as shown in  FIGS. 2-4 ; 
         FIG. 7  is a more detailed side view of the embodiment of the end cap shown in  FIG. 6  taken along line  7 - 7  of  FIG. 3  that illustrates a recessed opening for receiving a fastener; 
         FIG. 8  is an exploded perspective view of the inlet side of the embodiment of the air knife shown in  FIGS. 2-4 ; 
         FIG. 9  is an exploded perspective view of the adjustment side of the embodiment of the air knife shown in  FIGS. 2-4 ; 
         FIG. 10  is a front view of the embodiment of the air knife shown in  FIGS. 2-4  with the adjustment end facing forward, wherein the air knife is retained in a first rotational position by a tool-free fastener; 
         FIG. 11  is a partial cross-sectional view of the air knife, as shown in  FIG. 10 , taken along line  10 - 10 ; and 
         FIG. 12  is front view of the air knife, as shown in  FIG. 10 , wherein the air knife is repositioned to and retained at a second rotational position by the tool-free fastener. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments will be described below. These described embodiments are provided only by way of example, and do not limit the scope of the present disclosure. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments described below, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, while the term “exemplary” may be used herein in connection to certain examples of aspects or embodiments of the presently disclosed subject matter, it will be appreciated that these examples are illustrative in nature and that the term “exemplary” is not used herein to denote any preference or requirement with respect to a disclosed aspect or embodiment. Additionally, it should be understood that references to “one embodiment,” “an embodiment,” “some embodiments,” and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the disclosed features. 
     As discussed in further detail below, various embodiments of an air knife system are provided with improved end caps and mounting systems. In one embodiment, a system includes an air knife having a main body coupled to first and second end caps with having recessed fastener openings. The recessed fastener openings may be used to fasten the first and second end caps to the main body of the air knife. Further, the recessed fastener openings may prevent fasteners from protruding beyond the first end cap and the second end cap, thereby allowing for first and second mounting plates to be secured flush against the first and second end caps, respectively. In another embodiment, an air knife system includes a mounting system having first and second mounting plates configured to couple to first and second end caps, respectively, of the air knife. One of the first or second mounting plates may be secured to the air knife via a first fastener and a second fastener. The first fastener retains the air knife axially while providing a pivot point for rotational adjustments. The second fastener may be a too-free fastener, such as a hand lever, thumb screw, or a latch, which is operable without use of a tool. In certain embodiments, the second fastener is radially offset from the first fastener and is selectively securable to block all movement and releasable to permit rotational movement of the main body relative to the respective mounting plate. In other words, the first fastener may provide only one degree of freedom (e.g., rotational movement) of the main body relative to the respective mounting plate. 
     Turning now to the drawings,  FIG. 1  illustrates a processing system  10  that may incorporate one or more aspects of the presently disclosed techniques. The processing system  10  includes an air supply source  12  that may deliver a fluid (e.g., air) to air knives  14 A and  14 B along a flow path  16 . In the illustrated embodiment, the flow path  16  includes the fluid conduits  20 ,  22 ,  26 ,  36 , and  38 , the adapters  24  and  28 , and the divider  32 . 
     In the presently illustrated system  10 , the air supply source  12  may include a high flow centrifugal blower (“air blower”) which, in some embodiments, may include a supercharger and motor configuration. In one embodiment, the operating characteristics of the air blower  12  may provide an air flow having a pressure of between approximately 1-10 pounds per square inch (psi) and having a flow rate of between approximately 50-2000 cubic feet per minute (CFM) or more specifically, between approximately 150 to 1500 CFM. In some embodiments, the air blower  12  may be housed within an enclosure. The air blower  12  may be separated from the air knives  14 A and  14 B by a distance of 10, 20, 30, 40, 50, 100, or 200 feet or more. As such, the flow path  16  is configured to provide a path through which air provided by the air blower  12  may be routed and ultimately delivered to the air knives  14 A and  14 B. 
     The air blower  12  may include an outlet  18  coupled to the fluid conduit  20  that defines a first portion of the flow path  16 . The fluid conduit  20  may be coupled to the downstream fluid conduit  22  by way of a first adapter  24 . By way of example only, the fluid conduit  20  may be a hose, such as a flexible hose, and the fluid conduit  22  may be a pipe, such as a stainless steel pipe or a polyvinyl chloride (PVC) pipe. The adapter  24  may be configured to provide an interface for coupling the hose  20  and pipe  22 . For instance, the adapter  24  may include a first adapter end configured to couple to the hose  18 , and a second adapter end configured to couple to the pipe  20 . In this manner, the hose  20 , adapter  24 , and pipe  22  are fluidly coupled, thereby allowing air discharged from the outlet  18  of the blower  12  to flow from the hose  20  into the pipe  22 . 
     The flow path  16  continues to the distal end of the pipe  22 , which may be coupled to another hose  26  by way of a second adapter  28  that may be similar in design to the first adapter  24 . Thus, by way of the adapters  24  and  28 , the air flow from the blower  12  may be received by an inlet  30  of a manifold or flow divider  32 . The divider  32  may be configured to distribute or split the air flow to multiple outlets  33  and  34 . Additional fluid conduits  36  and  38  may respectively couple the outlets  33  and  34  to the air knives  14 A and  14 B, respectively. In the illustrated embodiment, the air knives  14 A and  14 B may each include an inlet ( 40 A and  40 B) configured for a hose connection, and the fluid conduits  36  and  38  may thus be provided as hoses, such as flexible hoses. In other embodiments, a pipe may be disposed between the divider  32  and one of the air knives  14 A or  14 B, whereby adapters similar to the above-discussed adapters  24  or  28  are coupled to each end of the pipe to facilitate a fluid connection between hoses extending from an outlet (e.g.,  33  or  34 ) of the divider  32  and from an inlet (e.g.,  40 A or  40 B) of one of the air knives (e.g.,  14 A or  14 B). A hose connection to an inlet of an air knife will be illustrated in more detail below with respect to  FIG. 8 . In some embodiments, the system  10  may include only a single air knife (e.g.,  14 A) and thus may not include a divider  32 . In such embodiments, the fluid conduit  26  may be coupled directly to the air knife  14 A. 
     As will be discussed further below, the air knife  14 A may include a main body having first and second end caps that define a plenum or fluid cavity for receiving an air flow via the inlet  40 A. In certain embodiments, the air knife  14 A may be formed of materials including aluminum, stainless steel, or some combination thereof. In some embodiments, the main body may be generally cylindrical in shape with one end along the cylindrical body tapering to form a narrow discharge outlet  42 A, which may include a single continuous slot or, in other embodiments, a series of narrow holes or openings. In embodiments utilizing such a design, the main body of the air knife  14 A may generally take the form of a tear drop shape. 
     In operation, the plenum may pressurize and discharge air received via the inlet  40 A through the outlet  42 A. By way of example, an outlet  42 A in the form of a continuous “discharge slot” may have a width of between approximately 0.025 to 0.1 inches, and may have an area that is substantially less than the area of the inlet  42 A. Accordingly, the air flow  44 A (which may take the form of an air “blade” having a “knife-like” edge) exiting the outlet  42 A of the air knife  14 A may have a velocity that is greater than the velocity of the air flow entering via the inlet  40 A. As can be appreciated, the air knife  14 B may be constructed in a manner that is similar to the air knife  14 A and, thus may operate in a similar manner. Further, while only two outlets  33  and  34  are shown in  FIG. 1 , it should be appreciated that the divider  26  may be configured to provide any suitable number of outlets, and may provide flow paths to any suitable number of devices, including additional air knives, additional dividers, manifolds, and so forth. 
     As shown in  FIG. 1 , the air flows  44 A and  44 B exiting the respective discharge slots  42 A and  42 B of each of the air knives  14 A and  14 B, may be directed towards the applications  48  and  50 , respectively, of the processing system  10 . For instance, the applications  48  and  50  may be transported through the system  10  along a conveyor belt  52  or some other suitable type of transport mechanism. As will be appreciated, the application represented by the system  10  may utilize the air flows  44 A and  44 B provided by the air knives  14 A and  14 B, respectively, for a variety of functions, including but not limited to drying products, removing dust or debris, coating control, cooling, leak detection, surface impregnation, corrosion prevention, and so forth. For instance, in certain embodiments, the system  10  may be a system for drying food or beverage containers, such as cans or bottles, or may be a system for removing dust and other debris from sensitive electronic products, such as printed circuit boards (PCBs) or the like. In addition, some embodiments of the system  10  may also utilize the air flows  44 A and  44 B may to clean and/or remove debris from the conveyer belt  52 . 
     In accordance with aspects of the present disclosure, the air knives  14 A and  14 B may each include an adjustable mounting system that enables a user to position each air knife so as to direct the exiting air flows  44 A and  44 B in a desired direction. For instance, in  FIG. 1 , the air knife  14 A is mounted within the system  10  and oriented such that the exiting air flow  44 A is directed in the downward vertical direction  46 . By comparison, the air knife  14 B is mounted within the system  10 , such that the exiting air flow  44 B is directed towards the application  50  at an angle that is offset with respect to the vertical direction  46 . As discussed below, the disclosed embodiments of the air knife  14 A and  14 B may provide angular positions ranging over a span of at least approximately 90, 180, 270, or 360 degrees, or an angular range between 0 and 360 degrees. 
     In certain embodiments, the adjustable mounting system may include a mounting plate that is fastened to a pivot point on an end cap secured to one end of the air knife body using a first fastener in conjunction with a spacer or standoff element. The first fastener blocks movement in an axial direction while the standoff provides clearance to enable pivotal movement in a rotational direction about the pivot point. A second fastener may be received at an adjustment point on the end cap that is radially offset from the pivot point. When the air knife is oriented to a desired position, rotational retention may be provided by securing the second fastener within the adjustment point. Such a mounting system will be discussed in further detail below with respect to  FIGS. 9-12 . 
     Referring now to  FIGS. 2-4 , several perspective views showing an embodiment of an air knife  14  that may be utilized in the system  10  of  FIG. 1  are illustrated. In order to facilitate a better understanding of the disclosure,  FIGS. 2-4  will generally be described together. Specifically,  FIG. 2  shows a perspective view of the air knife  14  from an inlet end.  FIG. 3  shows a perspective view of the air knife  14  from an adjustment end, opposite the inlet end. Further,  FIG. 4  shows another perspective view of the air knife  14  from the inlet end to more clearly depict the outlet  42 . 
     As shown in  FIGS. 2-4 , the air knife  14  includes a main body  60  which may have an axial length  61  (e.g., in the axial direction  73 ). By way of example only, the axial length  61  of the main body may be between approximately 0.5 feet to 4 feet (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4 feet). A first end cap  62  that includes the inlet  40  and a second end cap  64  are secured to opposite first and second ends of the main body  60  by one or more fasteners  66 . The fasteners  66  may be provided as screws, bolts, rivets, latches, stakes, or some other suitable type of fastening device. As discussed in more detail below with respect to  FIGS. 5-7 , the fasteners  66  are configured to secure the first end cap  62  (an “inlet-side end cap”) and the second end cap  64  (an “adjustment-side end cap”) through recessed openings formed along the outer perimeter of each end cap  62  and  64 . For instance, the fasteners  66  may be inserted through the recessed openings on the end caps  62  and  64  and into holes (not shown) on the main body  60 . In this manner, the main body  60  and the end caps  62  and  64  define a plenum or fluid cavity that receives an air flow entering via the inlet  40 . 
     In the present embodiment, the main body  60  has a tear drop shape or airfoil shape which includes a taper that forms a discharge slot  42 . In certain embodiments, the discharge slot  42  may have a width of between approximately 0.025 to 0.1 inches, and may have a length that is approximately equivalent to the length  61  of the main body  60 . Accordingly, air entering the inlet  40  may be pressurized within the main body  60  and discharged through the slot  42 , generally having an impact velocity that is greater than the velocity of the air entering the main body  60  via the inlet  40 . The main body  60  and the end caps  62  and  64  may be formed from aluminum, stainless steel, or any other type of suitable material that may provide a fluid-tight cavity for receiving the air flow via the inlet  40 . 
     As shown in  FIG. 2 , the inlet side of the air knife  14  includes the inlet  40  (e.g., an annular protrusion), which has an annular outer wall  70  and an annular inner wall  72 . An adjustable mounting system, which may include the mounting plates  76  and  78 , are also provided, and may be retained against the end caps  62  and  64 , respectively, as discussed below. The mounting plate  76  (referred to as the inlet-side mounting plate), which includes an opening  77  (e.g., a circular opening), may be fitted against the inlet-side end cap  62  such that the inlet  40  fits through the opening  77 . As will be appreciated, the inlet  40  and the opening  77  may be sized to accommodate any suitable fluid conduit for delivering and air flow from the blower  12  ( FIG. 1 ). For instance, in some embodiments, the inlet  40  may be joined to a fluid conduit, such that the outer wall  70  fits against an inner wall of the fluid conduit. By way of example only, the inlet  40  may be configured to fit with a flexible hose having an inside diameter of between approximately 2 to 6 inches (e.g., 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 6 inches). 
     In some embodiments, the outer wall  70  of the inlet  40  may include one or more surface features, such as spiral-shaped grooves or gripping teeth, which may grip the inner wall of the hose, thus facilitating a secure connection between the hose and the inlet  40 . The connection of the inlet  40  to the fluid conduit may thus retain the inlet-side mounting plate  76  in the axial direction  73 , i.e., between the inlet-side end cap  62  and a fluid conduit, while allowing the mounting plate  76  to rotate about the inlet  40  in the rotational direction  75 . 
     Referring to  FIG. 3 , the adjustment end of the air knife  14  includes the mounting plate  78  (referred to as the “adjustment-side mounting plate”), a tool-free fastener  84  with a handle  86  (e.g., a lever), a separator element  92  (e.g., a spacer or standoff), and a fastener  94  (e.g., a screw). The adjustment-side mounting plate  78  includes arcuate grooves or slots  88  and  90  that are radially offset (e.g., radial direction  74 ) from the fastener  94 . The end cap  64  may include an opening, such as a threaded hole, for receiving mating threads of the fastener  94 . As will be discussed in further detail below, the separator element  92  and the fastener  94  may provide axial retention (e.g., in direction  73 ) of the air knife  14 , but still permit a degree of rotational movement (e.g., in the rotational direction  75 ) suitable for pivoting the main body  60  about the rotational axis  68  to adjust the rotational position of the air knife  14 . In other words, the separator element  92  and the fastener  94  provide only one degree of freedom (e.g., rotational movement of the main body  60  relative to the mounting plate  78 ). In this manner, the direction of the exiting air flow  44  from the discharge slot  42  may be adjusted. 
     Once the air knife  14  has been oriented to a desired position, retention in the rotational direction may be accomplished via the tool-free fastener  84 . For instance, once a desired rotational position is obtained, the tool-free fastener  84  may be inserted through one of the arcuate grooves  88  or  90  and secured into a threaded hole on the end cap  64 . The tool-free fastener  84  may then be tightened via the handle  86  to retain the desired rotational position. As can be appreciated, the amount of adjustment in the rotational direction  75  is defined by the angular range provided by the arcuate grooves  88  and  90 . By way of example only, each of the arcuate grooves may provide an angular range of rotational movement over a span of at least approximately 90, 180, 270, or 360 degrees, or an angular range between 0 and 360 degrees. 
     As further shown in  FIGS. 2-4 , the mounting plates  76  and  78  each include openings  80 , which may be used to couple the mounting plates  76  and  78  to a component of the system  10  ( FIG. 1 ). Thus, in practice, the adjustable mounting system of the air knife  14  may be utilized such that the mounting plates  76  and  78  are fixedly coupled or anchored to the system  10 , and such that the mounting plates  76  and  78  may be coupled to a component of the system  10 , such as a stationary mounting arm, a robotic arm, or the like. Axial retention of the air knife  14  is provided on the inlet end by the connection of a fluid conduit to the inlet  40 , and on the adjustment end via the fastener  94  and separator element  92 . Prior to securing (e.g., tightening a threaded connection of) the tool-free fastener  84 , the air knife  14  may be pivoted about the rotational axis  68  until a desired orientation is obtained, at which point the tool-free fastener  84  may be secured to retain the desired rotational position. These features are illustrated more clearly with respect to  FIGS. 8-12 , which are described further below. 
     Referring now to  FIGS. 5 and 6 , the end caps  62  and  64  of  FIGS. 2-4  are illustrated in more detail. Specifically,  FIG. 5  shows the inlet-side end cap  62 , and  FIG. 6  shows the adjustment-side end cap  64 . As illustrated, the inlet-side end cap  62  has an outer face  100 , an inner face  102  (with the reference lead line shown partially in phantom), and a perimeter or edge  101  extending therearound and defining a thickness of the inlet-side end cap  62 . The inlet-side end cap  62  includes an opening  103  from which the inlet  40  extends. As discussed above, the inlet  40  includes an outer wall  70  that may be adapted to couple against an inner wall of a fluid conduit that provides an air flow (e.g., supplied by blower  12 ) to the air knife  14 . 
     The adjustment-side end cap  64  similarly includes an outer face  106 , an inner face  108  (with the reference lead line shown partially in phantom), and a perimeter or edge  107  extending therearound and defining a thickness of the adjustment-side end cap  64 . It should be noted that in the present embodiment, the perimeters  101  and  107  of the end caps  62  and  64 , respectively, define shapes that are substantially the same as the “tear drop” cross-sectional shape of the main body  60  (e.g., taken through a radial plane perpendicular to the longitudinal rotational axis  68 ). The adjustment-side end cap  64  also includes the openings  120  and  122 . The opening  122  may receive a threaded end of the fastener  94  which, in combination with the separator element  92 , provides axial retention of the air knife  14  and mounting plate  78 . The opening  120  may receive a threaded end of a tool-free fastener  84  to provide rotational retention of the air knife  14 . Thus, when securely threaded into each of the respective openings  120  and  122 , the fastener  94  and the tool-free fastener  84  ( FIGS. 2-4 ) may retain the position of the air knife  14  in axial (e.g., direction  73 ) and rotational (e.g., direction  75 ) directions, such that the “knife-edged” air flow exiting the discharge slot  42  may be directed towards a particular application (e.g.,  48  or  50 ). 
     As shown in  FIGS. 5 and 6 , each of the end caps  62  and  64  may include a plurality of recesses  110  formed along their respective edges  101  and  107 . Within each recess  110 , an opening  112  is provided through which a respective fastener  66  (e.g.,  FIGS. 2-4 ) may be inserted to secure the end caps  62  and  64  to the main body  60  of the air knife via threaded connections. For instance, the recessed openings  112  on the end caps  62  and  64  may generally align to corresponding screw holes on the inlet-side end and the adjustment-side end of the main body  60 , and the end caps  62  and  64  may be secured to the main body  60  by tightening the fasteners  66  within their respective corresponding threaded holes. 
       FIG. 7  illustrates a more detailed side view of a recess  110  on the end cap  64  taken along line  7 - 7  of  FIG. 3 . As depicted in  FIG. 7 , the adjustment-side end cap  64  may be secured against the main body  60  by one or more screws  66 . Each screw  66  may include a head  132  and a threaded portion  134  (shown in phantom). As illustrated, the screw  66  may be inserted through the recessed opening  112  of the recess  110  into a corresponding screw hole of the main body  60 . The opening  112  may be recessed from the outer face  106  of the end cap  64  by a distance  130 . In accordance with aspects of the present disclosure, the distance  130  may be selected such that the head  132  of the screw  66 , when threaded to the main body  60 , does not extend beyond the outer face  106  of the end cap  64 . In other words, the head  132  may be flush or recessed relative to the outer face  106 . By way of example only, the distance  130  may be between approximately 0.25 to 2 inches (e.g., 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.25, 1.5, 1.75, or 2 inches). 
     Although  FIG. 7  shows a detailed view of a recess  110  on the adjustment-side end cap  64  of  FIG. 6 , it should be understood that the recesses  110  on the inlet-side end cap  62  may be formed in a similar manner. Thus, the recessed openings  112  may allow for the screws  66  to secure the end caps  62  and  64  to the main body  60  without protruding beyond their respective outer surfaces  100  and  106 . As will be appreciated, this technique of providing recessed openings  110  for the fasteners  66  allows for the mounting plate  76  to fit flush against the outer face  100  of the inlet-side end cap  62 , and also allows for the mounting plate  78  to fit flush against the outer face  106  of the adjustment-side end cap  64 . 
     The manner in which the mounting plates  76  and  78  may be fitted against the end caps  62  and  64  may be better understood with reference to  FIGS. 8 and 9 . In particular,  FIG. 8  shows a partial perspective exploded view depicting how the mounting plate  76  and a fluid conduit  148  are fitted to the inlet end of the air knife  14 .  FIG. 9  further shows a partial perspective exploded view depicting how the mounting plate  78  may be secured to the adjustment end of the air knife  14  via the fasteners  84  and  94 . 
     Referring first to  FIG. 8 , the mounting plate  76  includes the opening  77 , an outer face  142 , and an inner face  144  (with the reference lead line shown partially in phantom). The inlet  40  (e.g., annular protrusion) may be figured to fit through the opening  77 , such that the inner face  144  of the mounting plate  76  fits against the outer face  100  of the end cap  62 . As discussed above, because the recessed openings  112  ( FIGS. 5-7 ) provide that the heads (e.g.,  132 ) of the fasteners  66  do not extend or protrude beyond the outer face  100 , the mounting plate  76  may be fitted flush against the outer face  100 . 
     A fluid conduit  148 , such as a hose, includes an outer wall  150  and an inner  152 . The inner wall  152  of the hose  148  may fit against the outer wall  70  of the inlet  40 . As discussed above, in some embodiments, the outer wall  70  of the inlet  40  may include one or more surface features, such as spiral-shaped grooves or gripping teeth, which may grip the inner wall  152  of the hose  148 , thus facilitating a secure connection between the hose  148  and the inlet  40 . When assembled onto the inlet  40 , the hose  148  may provide axial retention with regard to the mounting plate  76 . That is, the mounting plate  76  may be held in place by the hose  148  and the outer face  100  of the end cap  62 . 
     As mentioned above, the assembly of the adjustment-side mounting plate  78  to the end cap  64  may be facilitated by the fasteners  84  and  94 . For instance, as shown in  FIG. 9 , the mounting plate  78  includes an outer face  153  and an inner face  155  (with the reference lead line shown partially in phantom). The separator element  92 , which may include an axial spacer or standoff, and the fastener  94  may provide for axial retention of the air knife  14  (e.g., in the axial direction  73 ), while still allowing for the rotational position of the air knife  14  to be pivoted about the longitudinal axis  68 . For instance, the separator  92  includes an inner cylindrical portion  158  that has a smaller diameter compared to an outer cylindrical portion  157 . The inner cylindrical portion  158  may be fitted into the circular opening  154  on the mounting plate  78 , leaving the outer cylindrical portion  157  to extend from the outer face  153 . The fastener  94  includes a threaded portion  56 , which may be inserted through an opening  159  of the separator  92  and the opening  154  of the mounting plate  78  and threaded into the hole  122 , thereby securing the inner face  155  of the mounting plate  78  to the outer face  106  of the end cap  64  and providing for axial retention of the air knife  14 . As discussed above, due to the recesses  110 , the mounting plate  78  may be fitted flush against the outer face  106 . 
     As shown in the present embodiment, the hole  122 , opening  154 , separator  92 , and fastener  94  are all generally aligned with the longitudinal axis  68  of the air knife  14 . While the fastener  94  and separator  92  provide axial retention (e.g., via a friction fit), the rotational position of the air knife  14  may still be adjustable prior to tightening the tool-free fastener  84  within the hole  120 , i.e., via pivoting the air knife  14  about the longitudinal axis  68 . As discussed above, the tool-free fastener  84  includes a handle or lever  86  that enables a user to turn the fastener  84  clockwise or counter-clockwise without a separate tool. The assembly of the tool-free fastener  84  to the hole  120  may include inserting a threaded portion  162  of the fastener  84  through a washer  160  and through one of the arcuate grooves  88  or  90 . As discussed above, the arcuate grooves  88  and  90  may be provide for an angular range of rotational movement with respect to the rotational axis  68 , at which the fastener  94  acts as the pivot point. Thus, the relative location of the hole  120  for receiving the threaded portion  162  of the tool-free fastener  84  may vary within grooves  88  or  90  depending on the rotational position (e.g., in rotational direction  75 ) of the air knife  14 . 
     To retain a particular rotational position, the tool-free fastener  84  may be tightened (e.g., via clockwise rotation) within the threaded hole  120 . The foregoing technique provides for relatively easy adjustment of the rotational position of the air knife  14  to adjust the direction of the exiting air flow  44  ( FIG. 1 ) by: loosening (e.g., via counter-clockwise rotation) the tool-free fastener  84 , repositioning the air knife  14 , and then re-tightening the tool-free fastener  84  once a new desired rotational position is obtained. As will be appreciated, the rotational adjustment of the air knife  14  may be performed without completely removing the tool-free fastener  84  from the hole  120 . That is, the tool-free fastener  84  need only be loosened to allow for movement within the grooves  88  or  90  (although complete removal of the fastener  84  may be necessary if a user wishes to reposition the location of the hole  120  from the groove  88  to the groove  90 ). 
       FIGS. 10-12  depict the adjustment side of the air knife  14 , and further illustrate how the rotational position of the air knife  14  may be adjusted. For clarity, elements illustrated in  FIGS. 10-12  that have already been described above are labeled using like reference numbers.  FIG. 10  illustrates a front view of the air knife  14  with the adjustment end facing forward. As shown, the air knife  14  is retained in a first rotational position, such that the air flow  44  exiting the discharge slot  42  is directed downwards in the vertical direction  46 . 
     A cross-sectional view (taken along cut-line  10 - 10 ) of the air knife  14  in the first rotational position is further depicted in  FIG. 11 . As shown, the mounting plate  78  is secured flush against the adjustment-side end cap  64 . The separator  92  and fastener  94  are inserted through the opening  154  of the mounting plate  78 , and the threaded portion  156  of the fastener  94  may be threaded into the hole  122  to provide axial retention of the air knife  14 . Additionally, the threaded portion  162  of the tool-free fastener  84 , which is inserted through the washer  160  and the arcuate groove  88 , is threaded within the hole  120  to provide retention of the air knife  14  in the first rotational position, as shown in  FIG. 10 . 
       FIG. 12  shows a front view of the air knife  14  with the adjustment end facing forward, wherein the air knife  14  is repositioned to a second rotational position. As discussed above, the rotation of the air knife  14  may be about the rotational axis  68  ( FIGS. 2-4 ), whereby the fastener  94  acts as a pivot point for rotational movement. In the illustrated second rotational position of  FIG. 12 , the air knife  14  is rotated clockwise to an angle  168  with respect to the vertical direction  46 , such that the air flow  44  exits the discharge slot  42  at the angle  168 . As discussed above, adjusting the rotational position of the air knife  14  from the first rotational position of  FIG. 10  to the second rotational position of  FIG. 12  may include loosening the tool-free fastener  84 , repositioning the air knife  14  to the second rotational position, and then re-tightening the tool-free fastener  84  after obtaining the second rotational position. In this manner, the mounting system, which includes the plates  76  and  78  and the tool-free fastener  84 , may provide a technique for adjusting the position of an air knife that may be accomplished with relative ease and without requiring separate tools. 
     While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.