The present application relates generally to classifiers for use in the separation of particles according to size or mass. More specifically, the present application relates to static axial classifiers configured to more accurately separate the solid particles of fuel, such as coal, to make the combustion of the fuel more efficient and to reduce undesirable emissions.
It is generally well known to use particle classifiers, such as coal classifiers, in the power industry, such as for use in coal-fired power plants, burning in suspension. Typically, the particle classifier is positioned between a fuel crushing device (e.g., pulverizer) and a fuel combustion device (e.g., boiler, furnace). The coal enters the pulverizer as large irregular pieces and exits transformed into smaller more regular pieces, which are then directed into the classifier. The classifier separates the coal based on particle size or mass, where the larger particles are routed to pass through the pulverizer again for a further reduction in size, and where the smaller particles are directed to exit the classifier and enter the combustion device.
Typically, classifiers have been grouped into two types, static and dynamic. Conventional static classifiers generally involve the use of a fluid (e.g., air, gas) flow to generate centrifugal forces by cyclones or swirling flows to move particles to the periphery walls of the classifier where a combination of gravity and friction overcomes drag forces, which allows the heavier or larger particles to drop out of the flow and be rejected back to the pulverizer. Conventional dynamic classifiers generally involve the use of a rotating classifier blades to generate the centrifugal forces necessary to improve particle classification, wherein the rotating blades may physically impact with particles to reject them from the bulk fluid flow back to the pulverizer. The present application relates to an improved static classifier that more efficiently separates the coarse and fine particles of fuel, such as coal.
An example of a conventional static axial classifier 10 is illustrated in
Pneumatically conveyed pulverized coal enters the lower end of the inlet pipe 12 of the conventional static axial classifier 10, as illustrated by fluid flow 19. The fluid and coal particles exit the inlet pipe 12 and may collide with the outside surface of the cone 14 or the inside surface of the housing 11 while passing through the passage formed between the cone 14 and housing 11. The cross sectional flow area is also increased, slowing the flow. Some coal particles may contact the cone 14 or housing 11 will experience further velocity reductions due to friction off-setting upward drag forces from the fluid flow 19′. If the combination of gravity, friction, and inelastic collisions exceed the drag force created by the fluid flow, then the particles will stagnate and may fall or descend from the passage into the annular portion of the reclaim pipe 16, which transfers the coal back to the pulverizer. Other coal particles are dragged by the fluid flow 19′from the passage through the baffle 15 into the outlet pipe 13 (shown as fluid flow 19″), which ultimately transfers the particles toward the combustion zone, either directly or indirectly, as particles may be stored in a bin. The blades 15 forming the baffle are typically configured to direct the fluid flow 19′ to exit the baffle in the form of a cyclone or vortex, which increases the potential for gravity to overcome the fluid drag forces and allow particles to drop toward the reclaim pipe 16. The larger particles having relative higher momentum and inertia may impact or collide with the blades 15 to slow the particles through inelastic collisions. The imparted swirl, in conjunction with the change in flow direction at the roof of the housing 11, increases the potential for larger particles to impact stationary surfaces, which may slow the particles or redirect the impacted particles flow from the fluid flow direction toward the reclaim pipe 16.
Conventional static axial classifiers, such as the classifier shown in
With the increased use of combustion staging (internal or external to the primary flames), generally used for the control of the emissions of nitrogen oxides, the top size of particles injected into the combustion zone becomes a greater concern. Since the coal char or fixed carbon oxidizes on the surface exposed to the oxygen, the size of the particle and the particle's surface area to volume or weight ratio influences the overall reaction rate, during combustion. Thus, a smaller or fine particle will oxidize more quickly relative to a larger or coarse particle. Increasing the fraction of fine coal particles relative to total particles injected into the combustion zone, generally, improves the efficiency of combustion and emission control of the nitrogen oxides, while reducing the potential for unburned coal (or char) from leaving the combustion zone.
An exemplary embodiment relates to an axial classifier for separating the particles of a fluid flow based on the size of the particles. The classifier includes an inlet pipe having a first end and a second end wherein the first end receives the fluid flow from another device and the second end outputs the fluid flow, a reclaim pipe having an opening configured to receive the particles separated from the fluid flow, a reflecting cover provided above the inlet pipe for redirecting the fluid flow exiting the inlet pipe toward the reclaim pipe, and a housing forming a chamber for the fluid flow to flow therein, wherein the housing includes an opening for the fluid flow to exit the classifier. The second end of the inlet pipe is provided above the opening of the reclaim pipe, wherein the particles of the fluid flow are separated in the chamber after existing the reflecting cover.
Another exemplary embodiment relates to a power plant for producing electric power from the combustion of a fuel source. The power plant includes a pulverizer configured to reduce the particle size of the fuel source input into the pulverizer, a combustion device having an igniter and a combustion chamber wherein the igniter provides the heat to initiate the combustion of the fuel in the combustion chamber, and an axial classifier. The axial classifier is configured to separate the particles of fuel of a fluid flow received from the pulverizer, in order to transfer the separated coarse particles back to the pulverizer and to transfer the fine particles to the combustion device. The axial classifier includes an inlet pipe, a reflective cover, a deflecting member, a reclaim pipe fluidly coupled to the pulverizer, a fluid flow guide and a housing forming a chamber for the fluid flow to pass therein. The inlet pipe directs the fluid flow received from the pulverizer upwardly toward the reflective cover. The reflective cover redirects the fluid flow downwardly toward the deflecting member and reclaim pipe. The fluid flow guide is coupled to the housing and configured to influence the direction of the fluid flow, wherein the coarse particles are separated from the fluid flow and enter the reclaim pipe to pass back through the pulverizer to be resized, and wherein the fine particles of the fluid flow remain in the fluid flow and are redirected upwardly by the deflecting member toward an opening in the housing to pass into the combustion device.
The static axial classifiers described herein improve coarse particle separation efficiency over conventional classifiers, by reducing or eliminating the fraction of coarse particles relative to total particles that exit the classifier and hence are introduced to the combustion zone. The classifiers increase the fraction of fine particles relative to total particles entering the combustion zone, since a reduction in the mean particle size generally improves the efficiency of the combustion device, reduces the amount of undesirable emissions, and reduces the fraction of particles that exit the combustion zone unburned. The static axial classifiers disclosed herein increase the proportion of fine particles reaching the combustion zone by more efficiently separating the coarse particles from the fluid flow within the classifier and returning the coarse particles to the pulverizer for additional size reduction. The static axial classifiers disclosed herein are preferably for use in coal power plants to separate coal particles received from a pulverizer and transferred to a combustion zone, however it should be noted that these axial classifiers may be utilized for separating any material comprising a powder or a combination of particles for use in any industry.
The outlet pipe 40 may be strong and durable enough to withstand the potential internal pressure, impact and abrasion from high velocity coal particles. According to an exemplary embodiment, the outlet pipe 40 may be configured to pass fluid flow containing particles of fuel (e.g., coal) from the classifier 30 to either a storage bin or to the combustion zone, and includes a lower end 41 (or first end) and an upper end 42 (or second end). The lower end 41 of the outlet pipe 40 may couple to the upper portion 33 of the housing 31, and the upper end 42 may couple to a storage bin, to the combustion zone or to another pipe connected (e.g., fluidly coupled) to the combustion zone. The outlet pipe 40 may also be integrally formed with the housing 31, such that the upper end 42 has an opening that is configured to pass the fluid flow to the combustion zone either directly or through another pipe.
The inlet pipe 50 may be strong and durable enough to withstand the potential internal pressure, impact and abrasion from high velocity coal particles. According to an exemplary embodiment, the inlet pipe 50 may be configured to pass fluid flow 39 containing particles of fuel (e.g., coal), and may pass inside the reclaim pipe 35 and within at least a portion of the housing 31, such as the lower portion 32. The inlet pipe 50 may include a lower end 52 (or first end) configured to receive pressurized fluid and coal particles from a pulverizing device (e.g., pulverizer) and an upper end 51 (or second end) configured to output the fluid, including the coal particles, in an upward direction toward the reflecting cover 60. The upper end 51 of the inlet pipe 50 may be higher relative to the entrance 37 of the reclaim pipe 35. This configuration addresses the deficiency of conventional classifiers, which have the upper end of the inlet pipe configured relatively adjacent to the entrance of the reclaim pipe, such as shown in
The reflecting cover 60 may be strong and durable enough to withstand the potential internal pressure, impact and abrasion from high velocity coal particles. According to an exemplary embodiment, the reflecting cover 60 may include a top surface 61, an annular side wall 62, and an aperture or opening 63. The reflecting cover 60 may include a plurality of apertures or openings 63. The top surface 61 of the reflecting cover 60 may couple to the annular side wall 62 and may be a concave/convex shaped surface to deflect and re-route the fluid flow. According to an exemplary embodiment, the annular side wall 62 may have a substantially uniform diameter. According to another exemplary embodiment, the annular side wall 62 may have a varying diameter. For example, the annular side wall 62 may extend at an oblique angle towards the inlet pipe 50, thus forming a downwardly funneling or conical shaped exit portion 64. This configuration may increase the velocity of the fluid flow exiting the aperture 63 of the reflecting cover 60. According to an exemplary embodiment, the reflecting cover 60 may be open in the bottom, forming an aperture or opening 63 for receiving a portion of the upper end 51 of the inlet pipe 50. According to another exemplary embodiment, the upper end 51 of the inlet pipe 50 may end short of the opening 63 formed by the lack of a bottom surface of the reflecting cover 60.
According to yet another exemplary embodiment, the reflecting cover 60 may include a bottom surface (or bottom portion) that may couple to the upper end 51 of inlet pipe 50. The bottom surface (or bottom portion) may include one or a plurality of openings (or apertures) 63 to permit fluid flow 39 to pass. The bottom surface (or bottom portion) may also be configured as a baffle having a plurality of fins or blades to direct and regulate the fluid flow. The plurality of fins of the bottom portion may be separated by a plurality of openings (or apertures) 63, wherein the fins are aligned at a similar (or unique) oblique angle (relative to vertical) to control the direction of fluid flow 39 that exits the reflecting cover 60. The plurality of obliquely aligned fins of the bottom portion of the reflecting cover 60 may cause the fluid flow 39 to exit the reflecting cover 60 in the form of a cyclone or vortex to induce impact of the particles of the fluid flow 39, such as with each other, with the outside wall of the inlet pipe 50, and/or with the deflecting member 70. The drag forces acting on the coarse particles may be overcome by these impacts (e.g., with other particles, with the input pipe, with the deflecting member, with the housing, etc.), thereby causing the coarse particles to separate from the fluid flow 39 and descend to the reclaim pipe 35 of the classifier 30 to be redirected for additional size reduction, such as by the pulverizer.
The reflecting cover 60 is configured to redirect the fluid flow 39 containing coal particles from the substantially upward direction as carried through the inlet pipe 50 to the substantially downward direction when exiting through aperture 63 of the reflecting cover 60. The reflecting cover 60 may direct the fluid flow 39 at an oblique downward angle away from the reflecting cover 60. According to an exemplary embodiment, the reflecting cover 60 may direct the fluid flow 39 containing particles in a substantially downward direction along the outside surface or wall of the inlet pipe 50 toward the deflecting member 70.
The exit portion 64 of the reflecting cover 60 may be shaped to minimize the pressure drop losses at the flow transition from inside the reflecting cover 60 to below the reflecting cover 60. For example, the exit portion 64 may be flared, having a linear or curved shaped that extends away from the annular side wall 62. The shape of the exit portion 64 of the reflecting cover 60 may vary. As shown in
According to the exemplary embodiment shown in
The deflecting member 70 may be strong and durable enough to withstand the potential internal pressure, impact and abrasion from high velocity coal particles. According to an exemplary embodiment, the deflecting member 70 may extend at an adjustable oblique angle from the outer surface or wall of the inlet pipe 50 towards the inside surface or wall of the housing 31, where a gap 44 may formed between the housing 31 and the deflecting member 70 to allow coarse particles to pass through the gap 44 to enter the reclaim pipe 35.
The classifier may further include a linkage 72 and an adjustment mechanism 74, as shown in
The adjustment mechanism 74 and linkage 72 may be configured using any method for providing remote adjustment. For example, the linkage may include a threaded shaft that treads into the deflecting member 70 and has a handle as an adjustment mechanism 74 fixed to the other end of linkage 72. Rotating the adjustment mechanism 74 rotates the linkage 72, causing the deflecting member 70 to displace along the length of the linkage 72 driven by the treads, causing the end of the deflecting member 70 coupled to the linkage 72 to raise or lower (depending on the direction of rotation of the adjustment mechanism 74), while the other end of the deflecting member 70 may be fixed to the inlet pipe 50. Thus, rotation of the adjustment mechanism 74 may displace the end of the deflecting member 70 relative to the fixed end, while the fixed end remains stationary, therefore changing the angle of the deflecting member 70 relative to the inlet pipe 50 and housing 31. Alternatively, the adjustment mechanism 74 may displace or adjust the linkage 72 using any suitable method, such as using solenoids, fluid pressure or linear electric actuators.
According to another exemplary embodiment, the classifier 30 may include a linkage 72 and an adjustment mechanism 74, wherein the linkage 72 may couple to the deflecting member 70 at one end and may couple to the adjustment mechanism 74 at the other end. Adjustment (e.g., actuation) of the adjustment mechanism 74, may vary the elevation (e.g., height) of the deflecting member 70 relative to the inlet pipe 50 and the reflective cover 60, such as through the linkage 72. In other words, the position (e.g., the height) of the deflecting member 70 relative to the inlet pipe 50 may be adjusted, such as by actuation of the adjustment mechanism 74. The elevation (e.g., height) of the deflecting member 70 may be varied (e.g., increased, decreased) to influence the size of the particle that may be reclaimed by passing through the reclaim pipe 35 and/or that may pass through the outlet pipe 40. The classifier 30 may have a broad range of adjustment of the elevation of the deflecting member 70. For example, the linkage 72 may be threaded to the housing 31, wherein the rotation of the linkage 72 may move the end of the linkage 72 that is coupled to the deflecting member 70 in a linear (e.g., upward, downward) direction (depending on the direction of rotation of the linkage 72). Accordingly, the rotation of the adjustment mechanism 74 may in-turn rotate the linkage 72, such as relative to the housing 31, to move (e.g., displace) the linkage 72 to thereby adjust the elevation of the deflecting member 70.
The classifier may further include a support plate 38, which may be strong and durable enough to withstand the potential internal pressure, impact and abrasion from high velocity coal particles. The support plate 38 includes an outer surface coupled to the housing 31, and an inner surface coupled to the reflecting cover 60. The support plate 38 may provide structural support to the classifier 30 by maintaining the position of the reflecting cover 60 relative to the housing 31. According to an exemplary embodiment, support plate 38 may be annular shaped having an outer diameter which is coupled to the inside surface of the housing 31 and an inner diameter which is coupled to the outside surface of the side wall 62 of the reflecting cover 60. The support plate 38 may include a plurality of apertures to allow fluid flow 39 to pass therethrough without tailoring the direction of fluid flow. According to another exemplary embodiment, the support plate may be configured as a baffle having a plurality of fins or blades to tailor the direction of the fluid flow. Thus, the support plate may be configured to provide an additional (e.g., as second) method of particle separation.
The fluid flow 39 is illustrated in
As the fluid flow 39 travels downwardly, the velocity of the fluid flow may decrease, wherein the coarse particles may be separated from the fine particles that remain in the fluid flow through inertia (i.e., the resistance of the particles to change direction), gravity, friction, and inelastic collisions. Since the inertia of the particle, as well as the force induced by the acceleration of the particle, is effected by the mass of the particle, the coarse particles separate from the fluid flow by continuing to travel downwardly after contacting the inlet pipe 50, the housing 31 and/or the deflecting member 70 wherein the coarse particles enter the reclaim pipe 35 through the entrance 37 after passing through the gap 44. The inertia or momentum of the coarse particles coupled with gravity overcomes the drag forces of the fluid flow, allowing the coarse particles to pass to the reclaim pipe 35 for additional size reduction, such as in a pulverizer. However, the drag forces from the fluid flow turns the fine particles in a substantially vertical or in the upwardly direction to pass through the support plate and pass out the outlet pipe 40 toward the combustion zone. The inertia or momentum of the fine particles flowing in a downward direction may be overcome by the drag force of the fluid flowing in the upward direction, such that the fluid drives the fine particles upward with the pressurized fluid.
As shown in
The elevation (e.g., height) of the reflecting cover 260 may be varied (e.g., raised, lowered) to influence the size of the particle that may be separated from the fluid flow. The classifier 230 may allow a broad range of adjustment of the elevation of the reflecting cover 260. For example, the linkage 272 may be threaded to the housing 231, wherein the rotation of the linkage 272 may move the end of the linkage 272 that is coupled to the reflecting cover 260 in a linear (e.g., upward, downward) direction (depending on the direction of rotation of the linkage 272). Accordingly, the rotation of the adjustment mechanism 274 may in-turn rotate the linkage 272, such as relative to the housing 231, to move (e.g., displace) the linkage 272 to thereby adjust the elevation of the reflecting cover 260.
The classifier 230 may also include an adjustment mechanism 274 and/or a linkage 272 coupled to the reflecting cover 260 to adjust the cross-sectional area in which the fluid flow exits the reflecting cover 260. For example, the classifier 230 may be configured such that adjustment of the adjustment mechanism 274 may move the linkage 272 to thereby change (e.g., increase, decrease) the cross-sectional area of the exit of the reflective cover, such as by adjusting the reflecting cover 260 relative to the inlet pipe 250 and/or the housing 231. The fluid flow exiting the reflective cover 260 may be influenced by the adjustment of the cross-sectional area at the exit. For example, the reflective cover 260 may be adjusted to provide a Venturi effect on the fluid flow, whereby the velocity of the fluid flow may be increased with a corresponding reduction in the surface area at the exit of the reflective cover 260 or the velocity of the fluid flow may be decreased with a corresponding increase in the surface area. The ability to vary the cross-sectional area at the exit of the reflective cover 260 of the classifier 230, such as between the end of the exit portion 264 of the reflective cover 260 and the outside of the inlet pipe 250, allows the velocity and pressure (e.g., static) of the fluid flow exiting the reflective cover 260 to be varied to tailor the performance (e.g., classification) of the classifier 230.
The classifier 230 may also include a support plate 238 that is provided between the housing 231 and the reflecting cover 260. The support plate 238 may support the reflecting cover 260 to help the reflecting cover 260 maintain a concentricity to the inlet pipe 250, while allowing the reflecting cover 260 to move (e.g., upwardly, downwardly) relative to the support plate 238 to allow adjustment of the elevation of the reflecting cover 260. The support plate 238 and/or the reflecting cover 260 may include a bearing or have a bearing surface to allow efficient relative movement between them.
The classifier 230 may also include a fluid flow guide to help turn the fluid flow (and entrained fine particles) upwardly toward the outlet pipe 240 and/or to capture coarse particles to be reclaimed. As shown in
The fluid flow guides 277, 278 may help direct the fluid flow that enters the first chamber 234a (from the reflecting cover 260) upwardly toward the second chamber 234b to exit the classifier 230 through the outlet pipe 240. The fluid flow guides 277, 278 may turn the fluid flow, including the fine particles flowing therein, from the downwardly direction to the upwardly direction within the first chamber 234a. Additionally, the fluid flow guides 277, 278 may capture the coarse particles, which may get caught under the fins or veins, to separate the coarse particles to be reclaimed. It should be noted that the classifiers, as disclosed herein, may include any number of fluid flow guides having any suitable configuration and location within the classifier, and those embodiments shown and described herein are not meant as limitations.
The classifier 230 may also include a deflecting member 270, which may extend at an oblique angle from the outer surface of the inlet pipe 250 toward the inner surface of the housing 231. The deflecting member 270 may work alone or in conjunction with the fluid flow guides 277, 278 to help direct the fluid flow upwardly, while separating the coarse particles to be reclaimed.
The classifier disclosed herein advantageously utilizes the natural segregation of particles from the conveying medium streamline through a 180 degree change in direction. In the process, particle momentum and inertia, coupled with gravity and conveying medium velocities, are used to preferentially keep the finer (and lighter) particles entrained in the fluid flow 39, while rejecting the coarser (and heavier) particles in the process. For example, the coarse particles (e.g., particles having sizes greater than 300 microns) may be rejected in order to be reprocessed to reduce the size of the coarse particles. It should be noted that although the coarse particles are described above as particles having sizes greater than 300 microns, the classifiers disclosed herein may be configured (e.g., adjustable) to separate coarse particles having sizes that are less than 300 microns. For example, the classifiers disclosed herein may be configured to separate particles having sizes greater than 250 microns. The design velocities of the conveying medium through the classifier are such that the pressure drop through the classifier is nominally very small, particularly in comparison to swirling classifiers and dynamic classifiers. Similarly, the upper end 51, 251 (or outlet end) of the inlet pipe 50, 250 and/or the lower end 41, 241 (or inlet end) of the outlet pipe 40, 240 may be configured to minimize pressure drop losses at these flow transitions, such as by having contoured (e.g., curved, flared, angled) shapes.
The classifiers disclosed herein, such as classifier 30, are more efficient at separation (i.e., have a higher reclaim percentage of coarse sized particles and higher percentage of fine sized particles entering the outlet pipe) relative to conventional axial classifiers. This increased separation efficiency leads to an increased combustion efficiency, since the size of the particle and the surface area to weight or volume ratio of the particle effect reaction rates during combustion. The increased separation efficiency also generally reduces the carbon content of the fly-ash.
The reclaim pipe 35 may include an oblique guide surface 36 configured to direct the coarse particles that pass through the entrance 37 of the reclaim pipe 35 to be routed back to the pulverizer. The reclaim pipe 35 may include an exit 46 that may couple directly to the raw solid material feed for the pulverizer or may couple to a carrying pipe that transfers the coarse particles to the pulverizer. The classifier 30 may also include a valve (e.g., trickle, rotary) to discourage fluid flow back through (e.g., up) the reclaim pipe, in the reverse of the reclamation direction.
As shown in
As shown in
Conversely, the predictive analysis of
As shown in
As shown in
However, the predictive analysis of
The results of the CFD analysis are further illustrated in Tables 1-3 below. Table 1 illustrates the particle size distribution used by the CFD analysis. The results from Tables 1 and 2 show that the classifier of
With reference to
where R is the percent (%) material retained, x is the particle size in mm, k is the absolute size constant, and n is the size distribution constant. The x-axis of the Rosin-Rammler plot is on log scale representing the particle sizes plotted at their square hole mm equivalent. The y-axis of the Rosin-Rammler plot is a probability distribution based on the Rosin-Rammler equation above. The value for “n” corresponds to the slope of the line. The plot of
By way of illustration,
The static axial classifiers described and shown herein may be configured to separate coarse particles of fuel, such as coal, from a fluid flow including the fuel, wherein the fine particles of fuel may be used to generate heat and power in a power plant. For example, the power plant may produce electric power from the combustion of the fuel source, wherein the power plant includes a pulverizer, a combustion device, and an axial classifier provided therebetween. The pulverizer may be configured to reduce the particle size of the fuel source that is input into the pulverizer, then output the fuel having a reduced particle size to the axial classifier. The axial classifier may be configured to separate the particles (e.g., the coarse particles) of fuel from a fluid flow received from the pulverizer. The axial classifier may transfer the separated coarse particles back to the pulverizer and transfer the fine particles to the combustion device. The axial classifier may include an inlet pipe, a reflective cover, a deflecting member, a fluid flow guide, a reclaim pipe fluidly coupled to the pulverizer, and a housing forming a chamber for the fluid flow to pass therein. The inlet pipe may direct the fluid flow received from the pulverizer upwardly toward the reflective cover; wherein the reflective cover may redirect the fluid flow downwardly toward the deflecting member and reclaim pipe. The particles impact other particles, as well as the housing and inlet pipe, inducing forces (e.g., friction forces) that counteract the drag forces from the fluid flow that cause the coarse particles to be separated from the fluid flow and enter the reclaim pipe to pass back through the pulverizer to be resized and allow the fine particles to remain in the fluid flow. The fine particles of the fluid flow are then redirected upwardly toward an opening in the housing to pass into the combustion device, which includes an igniter and a combustion chamber. The igniter may provide the heat to initiate the combustion of the fuel in the combustion chamber.
As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.
It should be noted that the term “exemplary” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).
The terms “coupled,” “connected,” and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.
References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.
It is important to note that the construction and arrangement of the classifiers as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/397,903, filed Jun. 18, 2010, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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61397903 | Jun 2010 | US |