Abstract:
A vibratory material separating apparatus has at least two plateau conveying surfaces interrupted by a drop out opening. A composite mixture is conveyed by a vibrating action beyond the first conveying plateau and over a foraminous section in the first conveying plateau adjacent the drop out opening. Air is directed upwardly through the foraminous section to break apart the composite mixture, and an air supply formed by an air duct is also directed angularly in relationship to the plane of the first conveying plateau to further break apart the composite mixture and to propel particles of predetermined density and/or dimension to the landing area on the second conveying plateau. The air duct is adjustable between a first position and a second position to form an air stream having an adjustable and width. In another aspect, a separating tube is located between and spaced from the first and second conveying plateaus, within the drop out opening. The separating tube interacts with the air stream produced by the air duct to assist in carrying particles passing over the leading edge of the separating tube over the drop out opening and onto the landing area of the second conveying plateau.

Description:
REFERENCE TO PRIOR APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/613,137, entitled “Material Separator having an Adjustable Air Knife,” filed Sep. 24, 2004, incorporated herein by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present disclosure relates generally to vibratory process equipment, and more particularly to a vibrator material separator. 
   BACKGROUND 
   It is known to provide a vibratory conveying structure to separate composite mixtures including particles of different size and density. An exemplary use for such a structure is to separate accumulated materials in a wood yard. The composite mixture in this instance may include wood fiber, dirt, stones, steel, and/or other materials that commonly are found around such an operation. Other composite mixtures may include glass, plastic, paper, metal, or other materials. 
   A typical conveying structure may use a vibrating trough to advance the composite mixture from a supply source to a discharge area. The flow path along the trough is interrupted by a drop out opening. The composite mixture is directed from a first plateau across the drop out opening so that the trajectory of certain of the particles is intercepted by a landing surface at the discharge side of the drop out opening and beneath the elevation of the first plateau. A fixed width forced air supply is directed through the flow path and propels additional low density particles onto the landing surface or second plateau. The more dense particles fall to the bottom of the structure for accumulation in a first area while the particles on the landing surface are conveyed, typically by a vibratory force, to a second, separate area. 
   In some previous systems, the air supply impinging on the particles falling off of the first plateau into the drop out opening was ineffective in propelling the desired lower density particles to the landing area. For example, in some systems, the particles lodged together as clumps so that the force of the fixed width air stream was not sufficient to cause the particles to reach the landing area, though their individual weight dictated that they should follow the path of the low density material. As a result, sometimes an incomplete separation occurred. To attempt to break up the clumps, the air flow velocity was sometimes increased with a typical result that heavy unwanted particles were propelled across the drop out opening and onto the landing area. 
   In other systems, to attempt to break up the clumps, a foraminous fluidizing deck was provided in the conveying plateau adjacent the drop out opening for directing an air supply upward through the fluidizing deck. Air forcibly delivered through the fluidizing deck tended to aid in the initial break up of lumped particles, before the composite mixture entered the main air stream directed through the drop out opening. 
   However, in some instances, even the combination of a fluidizing deck and a fixed width main air stream proved ineffective in propelling the desired particles to the landing area. For example, in some instances, the composition of the particles varied depending upon initial make-up of the mixture, and/or depending upon the particular environment within which the apparatus operated. Thus, in some circumstances, the set up conditions of the fluidizing deck and the air stream were calibrated for the average composite mixture, and were sometimes not optimized for each particular mixture, resulting in incomplete separation. Consequently, a vibratory device having improved material separating capabilities is desired. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a vibratory material separator having an adjustable air knife in accordance with the teachings of the present disclosure. 
       FIG. 2  is a cross sectional view of the vibratory material separator of  FIG. 1 . 
       FIG. 3  is a plan view of the vibratory material separator of  FIG. 1 . 
       FIG. 4  is a cross sectional view of a main separation stage of the vibratory material separator of  FIG. 1  and showing the adjustable air knife in a first configuration. 
       FIG. 5  is a cross sectional view of the main separation stage of the vibratory material separator of  FIG. 1  and showing the adjustable air knife in a second configuration. 
       FIG. 6  is a bottom elevational view of the main separation stage of the vibratory material separator along line  6 - 6  of  FIG. 5 . 
       FIG. 7  is a cross sectional view of the main separation stage of the vibratory material separator similar to  FIG. 4  and showing a separation tube. 
   

   DETAILED DESCRIPTION 
   The examples described herein are not intended to be exhaustive or to limit the scope of the disclosure to the precise forms disclosed. Rather, the following exemplary embodiments have been chosen and described in order to best explain the principles of the disclosure and to enable others skilled in the art to follow the teachings thereof. 
   Referring now to  FIGS. 1-3  of the drawings, a vibratory material separator  10  constructed in accordance with the teachings of the present disclosure is illustrated. The vibratory material separator  10  includes a trough  12  with an input end  14  and an open discharge end  16 . The trough  12  includes a conveying surface  18  divided into two generally horizontally disposed vertically spaced plateaus including a first conveying plateau  20  and a second conveying plateau  22  between which a drop out  24  is defined. The trough  12  has a hopper  26  adjacent the input end  14  to admit a composite mixture from a supply source (not shown). A hood  30  encloses the trough  12  to confine very light particles of the composite mixture entrained in a forced air stream as described below. 
   The trough  12  is supported for vibratory motion relative to a base  32 , bearing against a support surface  34 . In this example, the trough  12  is suspended such that the trough  12  slopes generally downward from the input end  14  towards the discharge end  16  to assist in motion of the mixture as described below. Resilient isolation members  36 , seated on corresponding isolation seats  40 , are located between the trough  12  and base  32 . The isolation members  36  may be, for example, marshmallow type isolation springs. It will be appreciated, however, that any other suitable isolation spring and/or resilient member may be used. 
   The separator  10  includes a vibratory actuator  42 , which may be a mounted motor associated with an eccentric drive as is known. The vibratory actuator  42  may be coupled to the trough  12  through at least one link  44  such as, for instance, a spring assembly. Together, the actuator  42  and the at least one link  44  impart a controlled vibratory conveying force to the trough  12 . The vibratory force moves the trough  12  in a vibratory motion that advances material on the trough  12  in a series of gentle throws and catches between the input end  14  and the discharge end  16 . 
   An exemplary first separation stage  50  is illustrated generally in  FIGS. 1-2 . The first separation stage  50  includes a deck  52  coupled to the first conveying plateau  20  in a substantially co-planar configuration. The deck  52  may be, for example, a solid deck, a finger screen deck, or any other suitable deck. When utilizing a finger screen deck, “fine” particles of a predetermined size may fall through the first conveying plateau  20  for collection. For example, the deck  52  may include a plurality of apertures sized to allow particles below one-half inch in size to pass through the deck  52 . To facilitate the collection of fine particles, the first separation stage  50  may additionally include a first discharge chute  54  to discharge, funnel, and collect any material which may fall through the deck  52 . 
   Additionally, located above the first conveying plateau  20 , and in this example suspended from the hood  30  above the deck  52 , is a flexible flap  56 . The flexible flap  56  may be constructed of any suitable material, including, for example, cloth, rubber, and/or the like. The flap  56  may assist in the confinement of particles of the composite mixture entrained in a forced air stream as described below, and may additionally aid in the prevention of any particle from traveling against the intended flow path, as will be better understood below. 
   As shown in  FIGS. 1-3 , the separator  10  further includes a pair of pressurized chambers  60 ,  62  supplied with air by a remote blower  64  mounted to the surface  34  separate from the trough  12 . The blower  64  communicates through a pair of flexible conduits  66 ,  68  with the inside of each pressure chamber  60 ,  62  through air intakes  70 ,  72 . The conduits  66 ,  68  can be readily attached and removed by use of band claps  74 ,  76 . Additionally, the amount of air flowing into the flexible conduits may be controlled by the utilization of slide gates  77 ,  79 . It will be appreciated that the conduits  66 ,  68  may be attached to the pressure chambers  60 ,  62  in any suitable manner, and additionally, the air flowing through the conduits  66 ,  68  may controlled by utilizing any suitable control means, including, for example, separate blowers, control valves, and/or similar control. 
   The separator  10  also includes a second or main separation stage  80  shown in detail in  FIGS. 4-5 . The second separation stage  80  generally includes the first conveying plateau  20 , the pressure chambers  60 ,  62 , an adjustable fluidizer deck  82 , an adjustable air knife  84 , the drop out  24 , an adjustable landing plate  86 , the second conveying plateau  22 , and a second discharge chute  90 . 
   In the illustrated example, the pressure chamber  62  is defined, at least in part, by the first conveying plateau  20 , the fluidizer deck  82 , and walls  94  and  96 . As mentioned before, the pressure chamber  62  is in communication with the blower  64  through the conduit  68  secured to the air intake  72 . The pressure chamber  62  also has part of its lower surface common with an air knife baffle  100  to give an upward trajectory to air flowing through the pressure chamber  62 . The fluidizer deck  82  is defined as lying in a plane above the pressure chamber  62  extending between the first conveying plateau  20  and an end of the air knife baffle  100 . The fluidizer deck  82  is a foraminous surface  102  having openings  104 , which are, in this example, louvered openings. The openings  104  are of a size determined by the fluidizing properties of the material. For example, bark chunks typically require more fluidizing air and therefore may need larger openings  104 , while saw dust typically needs less fluidizing air and therefore may need smaller openings  104 . It will be appreciated that the fluidizer deck  82  may optionally be a solid surface, wherein the deck  82  effectively closes the pressure chamber  62 . 
   The pressure chamber  60  is defined, at least in part, by the first conveying plateau  20 , a wall  108  of the first discharge chute  54 , a bottom wall  110 , walls  94  and  96 , air knife baffle  100  and an adjustable deflector plate  112 . Similar to the pressure chamber  62 , and as mentioned above, the pressure chamber  60  is in communication with the blower  64  through the conduit  66  secured to the air intake  70 . The adjustable deflector plate  112  extends angularly upwardly from the bottom wall  110  of the trough  12  and runs generally parallel to the air knife baffle  100 . Together, the baffle  100  and the adjustable deflector plate  112  form the air knife  84 , which directs the air from the pressure chamber  60  upward into the drop out opening  24 . The adjustable air knife  84 , therefore, causes air from the pressurized chamber  60  to impinge upon particles passing over an edge  114  of the first conveying plateau  20 . The action of the air upon the particles separates heavier and lighter particles. 
   In particular, the vibratory motion of the trough  12  causes the composite material, which is composed of materials of various densities, to move over the fluidizer deck  82  wherein the material is fluidized as it passes over the openings  104  in the foraminous surface  102 . Air from the pressure chamber  62  blows up through the openings  104  to initially tumble and agitate the large bound together clumps. The fluidizing air works the various sized parts of the disintegrating clumps to form a bed of the parts of the composite material, allowing the heavier fraction to collect at the bottom or lower level of the bed. This causes some of the lighter loose particles to bob and jump above the upper level of the bed. The air from the pressure chamber  62  adds to the vibratory motion to increase the agitation and tumbling of the composite material for abrading one clump against another and at the same time the pressurized air emitting from the openings  104  in the foraminous surface will tear, shred and rip the clumped and matted mass apart prior to the main separation stage  80  of the separator  10 . 
   Fluidizing air works the composite material bed and allows the heavier fraction to collect at the bottom or lower level of the bed. This allows the heavier particles to fall down through the adjustable air stream formed by the air knife  84 , reducing lighter particles from hitting or impacting on heavies causing incomplete separation. The openings  104  in the foraminous surface  102  may be aimed in any desired direction, including for example, a generally perpendicular direction to the surface  102 . The lighter loose particles that are carried forward toward the second conveying plateau  22  will be picked up by the air stream formed by the air knife  84  and propelled to the second conveying plateau  22  and/or onto the landing plate  86  where they will be conveyed and separated as any material falling thereon from the first conveying plateau  20 . The particles that fall short will pass through the second discharge chute  90 . Furthermore, any particles that may be blown “back” toward the inlet end  14  may be confined by the flap  56 . 
   As noted above, the deflector plate  112  is adjustably mounted to the bottom wall  110  of the trough  12  and is shiftable between a first position ( FIG. 4 ) and a second position ( FIG. 5 ). For example, as shown in  FIG. 6 , the deflector plate  112  may be mounted to the bottom wall  110  of the trough  12  within at least one transverse slot  116 , whereby, for purposes of adjustment, the deflector plate  112  may be shifted to alter the width of the air knife  84 . 
   Turning to  FIG. 4 , the deflector plate  112  is illustrated in the first position. Specifically, the deflector plate  112  is adjusted toward the baffle  100  such that the width of the air knife  84  is narrowed. In this example, the width of the air knife  84  may be approximately one inch (1″) to one and one-quarter inches (1¼″). By adjusting the deflector plate  112  towards the baffle  100 , the air stream, or column of air passing between the pressurized chamber  60  and the drop out opening  24 , will characteristically have a high velocity, narrow width profile. The high velocity, narrow width profile may be well suited for separating two or more commingled, relatively light objects, such as paper and glass. 
   Turning to  FIG. 5 , the deflector plate  112  is illustrated in the second position, wherein the deflector plate  112  is adjusted away from the baffle  100  such that the width of the air knife  84  is enlarged. By adjusting the deflector plate  112  away from the baffle  100 , a column of air passing between the pressurized chamber  60  and the drop out opening  24  will characteristically have a lower velocity, wider width profile. The lower velocity, wider width profile may be well suited for separating other, heavier commingled objects, such as wood and rock. 
   While each of the first and second positions (and any number of various position therein between) is well suited to separate heavier and lighter particles as described above, each column of air formed by the two adjusted positions may be better suited for different compositions. It can be seen that by adjusting the width of the air column to suit the particular composition of the particles, higher density particles will drop through the air column and fall into the second discharge chute  90 . The less dense material will be carried by the air column and will fall onto or over the landing plate  86  for collection by the second conveying plateau  22 . Graduated adjustments to the deflector  112  can be made to choose a desired line of separation. By adjusting the widths of the air column, the separator  10  may be configured to separate a variety of composite mixtures within the same physical trough dimensions. In this way, a single separator  10  may service a number of different environments. 
   Additionally, as illustrated in  FIG. 4 , the landing plate  86  may be adapted to adjust the size of the drop out opening  24  and to adjust the angle of the landing surface. For example, in this embodiment, the landing plate  86  includes flanges  87  on each end of the plate. A pivot rod (not shown) passes through one of at least one opening  88  in the side walls of the trough  12  and is secured thereto by, for example, nuts threaded on threaded bolt ends. The first one of the flanges  87  has an opening through which the bolt passes to secure the end of the plate to the sidewalls trough  12 . The second one of the flanges  87  is secured by nuts and bolts to the side walls of the trough  12  extending into opposed arcuate shaped slots  89 . Loosening the nuts on the bolts will permit the angle of the landing plate  86  to be changed. Additionally, mounted on the plate  86  is an extension  91  which is slideably adjustable toward and away from the drop out opening  24 . The slideable adjustment is effected by studs  93  on the undersurface of the extension  91  engaging through slots  95  in the extension  91 , which are locked in place by a nut. 
   The second separation stage of  FIGS. 4 and 5  may have an optional separation member, such as the exemplary separation tube  120  illustrated in  FIG. 7 , disposed between the first conveying plateau  20  and the second conveying plateau  22  and extending substantially along the width of the trough  12 . The separation tube  120  is located within the drop out opening  24  and spaced from the first conveying plateau  20  and the landing plate  86  of the second conveying plateau  22 , forming a first drop out sub-opening  122  and a second drop out sub-opening  124 . In the illustrated example, the separation tube  120  is positioned so as to interact with the air stream produced by the air knife  84  to produce desirable air flow characteristics. In one example, the separation tube  120  is spaced approximately 195 mm away from the edge  114  of the foraminous surface  102  and 65 mm away from the leading edge of the landing plate  86 . The separation tube  120  may additionally be mounted to the trough  12  by a shaft  115  positioned eccentric with respect to a center of the tube  120 . Accordingly, the position of the separation tube  120  may vary within the drop out opening  24  by rotating the tube  120  about the shaft  115 . Alternatively, the separation tube  120  may be mounted on an adjustable shaft (not shown), such as a shaft mounted in a generally transverse slot, such that the position of the tube  120  may be varied. Additionally, the size and shape of the tube  120  with the drop out  24  may be chosen based on any number of desired design characteristics. 
   In particular, in the illustrated embodiment, the separation tube  120  is a cylindrical tube having a generally circular cross section and includes an upper surface  130 , a lower surface  132 , a leading edge  134  and a trailing edge  136 . It will be appreciated, however, that the separation tube  120  may have any suitable shape, including, for example, semi-circular, arcuate, annular, air foil, or the like. 
   In operation, the separation tube  120  interacts with the air column produced by the air knife  84  to aid in the separation of the composite material. Specifically, the separation tube  120  may be placed within and/or below the air stream formed by the air knife  84  to produce an “air-foil” effect on the air stream whereby at least a portion of the air stream travels over the upper surface  130  of the separation tube  120 . The “air-foil” effected air stream will thereby have a “lift and carry” effect on any material traveling within the stream. For example, as described above, the composite material will pass over the edge  110  of the first conveying plateau  20  and pass into the air stream formed by the air knife  84 . Material having a relatively dense structure will pass through the air stream and fall through the first drop out sub opening  122  into the second discharge chute  90 . Alternatively, some material having a relatively dense structure will strike the leading edge  134  of the separation tube  120  and will be deflected downward through the opening  122 . 
   The remaining material will be lifted and carried by the “air-foil” effected air stream over the separation tube  120 . Of the remaining material carried over the separation tube  120 , some of the larger remaining particles may be heavy enough to fall out of the “air foil” affected air stream, and fall through the second drop out sub-opening  124 , ultimately passing through the second discharge chute  90 . The remaining lighter loose particles will continue to be propelled over the separation tube  120 , over the second drop out sub-opening  124  and toward the second conveying plateau  22  and/or onto the landing plate  86 , where they will be conveyed and separated as any material falling thereon from the first conveying plateau  20 . 
   By varying the shape and position of the separation tube  120 , as well as by optionally varying the width and/or velocity of the air stream, the separator  10  may be optimized for a variety of composite mixtures. Furthermore, while specific embodiments are disclosed herein, there is no intent to limit the invention to such embodiments. On the contrary, the disclosure of this application is to cover all modifications and embodiments fairly falling within the scope of the disclosure.