Abstract:
A discharge valve assembly is provided for discharging bulk material from a container having an opening formed in the lower portion thereof. The discharge valve assembly includes a discharge valve that is movable between opened and closed positions and typically disposed adjacent the opening in the container. An actuating assembly is operatively connected to the discharge valve for moving the discharge valve between open and close positions. The discharge valve includes a pair of generally flat surfaces that form at least a part of an upper portion of the discharge valve. The generally flat surfaces of the discharge valve taper generally inwardly and upwardly. Further, the pair of generally flat surfaces extend upwardly and inwardly and wherein there is formed about a top of the discharge valve a horizontal edge that extends horizontally across the discharge valve and above a substantial portion of the pair of generally flat surfaces.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to Provisional U.S. Patent Application Ser. No. 61/385,198 filed Sep. 22, 2010. The disclosure of that application is expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to material handling and more particularly to a discharger for directing bulk material to and through an opening of a container holding the bulk material. 
       BACKGROUND OF THE INVENTION 
       [0003]    Typically, the flow of bulk material downwardly through a hopper is controlled by a discharge valve disposed over an opening in a hopper, bin or other material handling structure. The discharge valve is movable between a closed position where it seats in the opening and an extended position where the discharge valve is elevated over the opening. In the open position, material flows downwardly around the discharge valve in an annulus flow configuration and through the opening in the hopper or other material handling structure. 
         [0004]    For the most part, discharge valves of the prior art have assumed the shape of an inverted cone or have been pyrimoidal shaped. Such discharge valves have numerous drawbacks and shortcomings. In many applications employing these prior art discharge valves, the bulk material under certain conditions does not flow efficiently across the surfaces of the discharge valve. Under some circumstances a cone or pyramidal shaped discharge valve is unable to overcome the powder or bulk solids strength or consolidation to induce flow. 
         [0005]    Therefore, there has been and continues to be a need for a discharge valve that facilitates a downward annulus flow around the discharge valve and where the upper initial contact surfaces of the discharge valve are designed to facilitate flow from hoppers, silos and other similar material storage or handling structures. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to a discharger having a discharge valve for controlling the flow of bulk material from a hopper, silo or other material holding structure (as well as portable hoppers and bins) where the discharge valve includes at least two flat surfaces that taper inwardly and upwardly to meet and form an upper edge. This results in the discharge valve assuming a wedge or chisel shape about the upper portion thereof. 
         [0007]    Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view showing the wedge or chiseled-shaped discharge valve disposed in an open position over an opening in a hopper. 
           [0009]      FIG. 2  is a fragmentary perspective view of an alternative design for the discharge valve, but wherein the discharge valve still includes two generally flat surfaces that taper inwardly and upwardly to form an edge. 
           [0010]      FIGS. 3A and 3B  show an alternative discharge valve that includes an air plenum that extends over the wedge or chisel-shaped discharge valve. 
           [0011]      FIGS. 4A ,  4 B and  4 C show the discharger and discharge valve of the present invention disposed within a hopper and  FIGS. 4A and 4B  specifically show one type of actuator that can be employed to move the discharge valve between open and close positions. 
       
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0012]    With further reference to the drawings, a discharger is shown therein for controlling the flow of powder or bulk solids through an opening in a hopper or a container that contains the powder or bulk solids. More particularly, the discharger includes a discharge valve that is indicated generally by the numeral  10 . As will be appreciated from subsequent discussions, the discharge valve  10  facilitates the flow of powder or bulk solids through an opening in a hopper or a container that contains the powder or bulk solids. In the embodiments illustrated, the upper portion of the discharge valve assumes a wedge or chisel shape. Discharge valve  10  is usually disposed over an opening such as an opening in a hopper. Typically powder or other bulk material is held within the hopper or container and extends around the discharge valve  10 . Discharge valve  10 , which will be discussed in more detail subsequently herein, is movably mounted for movement between a seated or closed position (FIG.  4 A) in the opening to an extended or open position ( FIG. 2B ) above the opening. In the seated position, the discharge valve  10  effectively closes the opening in the hopper or container and prevents the flow of powder or bulk material through the opening therein. In the extended position, the discharge valve  10  rises above the opening and the opening in the hopper or the container is open such that powder and bulk material can flow around the discharge valve  10  and downwardly through the underlying opening. This gives rise to what is sometimes referred to as an annulus flow. This is because the flow pattern of the powder or bulk material assumes an annulus configuration as the powder or bulk material passes downwardly past the discharge valve  10 . 
         [0013]    The term “bulk material” is a broad term that means granular or powder material, such as for example, grains and other fine particled material of all types. 
         [0014]    Discharge valve  10  can take on various overall shapes but the upper portion includes a wedge or chisel shape. 
         [0015]    With particular reference to the drawings and the discharge valve  10 , it is seen that the upper portion of the discharge valve includes two generally flat and planar surfaces  12  and  14 . Each of the surfaces  12 ,  14  taper inwardly and define an upper elongated edge  16 . Edge  16  extends horizontally a substantial distance across the upper extremity of the discharge valve  10 . The remaining structure of the discharge valve  10 , that is the structure other than the surfaces  12 ,  14  and edge  16 , can vary. 
         [0016]    In the case of a first embodiment, that is the embodiment shown in  FIG. 1 , the discharge valve  10  includes a round base  18 . Also, the discharge valve  10  includes opposed curve sides  20  that sweep upwardly from the base  18  and join the flat surfaces  12 ,  14 . 
         [0017]    The first embodiment shown in  FIG. 1  is but one example of the overall shape of the discharge valve  10 . The base could be square, rectangular or various shapes and the sides could also be of various configurations and shapes. For example, see the embodiment shown in  FIG. 2 . In the embodiment of  FIG. 2  the discharge valve  10  still includes the wedge or chisel shape. That is, it includes the upper and inwardly tapering flat surfaces  12  and  14  that form the edge  16 . However, in the case of the embodiment shown in  FIG. 2 , the flat surfaces  12  and  14  are generally triangular shaped. The remaining structure of the second embodiment of the discharge valve  10  shown in  FIG. 2  is similar but not identical to that shown in  FIG. 1 . In the  FIG. 2  embodiment, each side includes two different surfaces  20 A and  20 B. 
         [0018]    The discharge valve  10  is typically contained within a hopper, a silo or other structure (fixed or portable) that holds bulk material or powder. In the drawings, the discharge valve  10  is shown in connection with a hopper indicated by the numeral  30 . See  FIGS. 4A ,  4 B and  4 C. Again, it is appreciated that the discharge valve  10  could be utilized in many different types of structures that hold powder or other bulk material. In any event, hopper  16  includes a surrounding sidewall structure that tapers downwardly to a lower opening  32  formed in the hopper. Typically the sidewall structure of the hopper tapers inwardly and downwardly towards the opening  32  and towards the discharge valve  10  that is disposed above the opening  32 . It is appreciated that when the hopper  30  is full of particles, bulk solids, powder, etc., the discharge valve  10  will project into the material within the hopper  30 . Upon actuation the discharge valve  10  moves from the seated or closed position upwardly into the material. This upward movement unseats the discharge valve  10 , exposing the opening  32  underneath. Then this results in a downwardly directed flow of bulk material through the hopper, around the discharge valve  10  and into and through the opening  32 . As discussed above, the flow configuration will be that of an annulus flow pattern since the bulk material is constrained to flow around the discharge valve  10 . 
         [0019]      FIGS. 3A and 3B  show an alternate embodiment for the discharge valve  10 . Basically the discharge valve  10  assumes the same basic wedge or chisel shape as discussed above, but in this embodiment, an air plenum is formed on the wedge surfaces  12  and  14  for disbursing air outwardly from the wedge shape surfaces  12  and  14 . The disbursement of air outwardly from the surfaces  12  and  14  facilitates the flow of bulk material downwardly past the discharge valve  10 . With continuing reference to  FIGS. 3A and 3B , disposed over each surface  12  and  14  is a plenum plate  40 . The plenum plates  40  are spaced slightly above the flat surfaces  12  and  14  so as to define an air space between the surfaces  12  and  14  and the plenum plates. The plenum plates includes an array of openings formed therein that permits air to be forced through the plenum space and outwardly through the various openings in the plenum plates, 
         [0020]    The formed air plenum is operatively connected to a source of compressed air. Although not shown, the source of compressed air would be operatively connected to one or more air conduits that extend from the compressed air source through the main body of the discharge valve  10  and ultimately to the air plenum. This would enable air to flow under pressure from the compressed air source, through the air conduits, through the main body of the discharge valve  10  into the air plenum defined between the flat surfaces  12  and  14  and the plenum plates  40 . Various conventional controls can be provided for actuating the air supply and even controlling the air pressure or air flow exhausted from the air plenum. 
         [0021]    The air plenum discussed above facilitates the movement of material across the upper surfaces of the discharge valve  10 . This makes it less likely that material would not freely flow across the surfaces of the discharge valve  10 . The air prevents material from lodging or simply remaining on the upper portion of the discharge valve  10 . That is, the air being exhausted through the plenum plates  40  actively induces the material to flow downwardly and around the discharge valve  10 . 
         [0022]    The discharge valve  10  discussed above has many and varied applications. For example, the discharge valve  10  can be used in agricultural, pharmaceutical and biotechnical applications as well as any applications where one is faced with dispensing powder or bulk material such as grain, particles, powder, etc. 
         [0023]    Attention is now directed to  FIGS. 4A ,  4 B and  4 C. This discloses one exemplary actuation system for moving the discharge valve  10  up and down with respect to the underlying opening  32  in the hopper  30 . Note in  FIG. 4A , that the discharge valve  10  is seated in the opening  32  of the hopper  30  and is therefore disposed in a closed position.  FIG. 4B  shows the discharge valve  10  in an open position. Here the discharge valve  10  is elevated with respect to the opening  32  in the hopper  30  so as to permit the flow of bulk material to flow downwardly past the discharge valve  10  into and through the opening  32 . 
         [0024]    There are various ways to actuate and move the discharge valve  10  between closed and open positions. The actuating mechanism shown in  FIGS. 4A and 4B  is but one example of a suitable type activating mechanism. 
         [0025]    With reference to  FIG. 4A and 4B , there is provided a transfer hopper or chute that is suspended from the hopper  30 . Note that the transfer hopper or chute includes two portions, a rigid lower section  50 A and a flexible upper section  50 B. Note in  FIG. 4A  where the upper section  50 B is extended and the transfer hopper is relatively deep.  FIG. 4B  illustrates the lower section  50 A being raised and in the process the flexible upper section of  50 B tends to curl and includes some general overlapment. 
         [0026]    A support structure for supporting the discharge valve  10  is contained within the transfer hopper  50 A,  50 B. This structure in this example includes three gussets  52 . Each gusset  52  is welded or secured by suitable means to the inner wall of the lower section  50 A of the transfer hopper. Each gusset  52  extends inwardly and upwardly. A support plate  54  is secured to the top of the gussets  52 . The discharge valve  10  is in turn secured to the support plate  54  by a series of bolts. 
         [0027]    Extending outwardly from the outer wall of the lower section  50 A of the transfer hopper is a series of uniformly spaced plates  56 . Associated with each plate is a bushing  58 . There is provided a series of pneumatic bladders that underlie the respective plates  56  and which rest on a surrounding frame structure. Plates  56  in turn rest on the pneumatic bladders  60 . The bushings  58  are mounted on vertical guide rods  62 . The vertical guide rods  62  form a part of the surrounding frame structure. Thus it follows as the pneumatic bladders  60  are inflated, the plates  56  along with the bushings  58  move upwardly. The bushings  58  surrounding the vertical guide rods  62  and maintain the transfer hopper and discharge valve  10  in proper alignment with respect to the opening  32  in the hopper  30 . There is also provided on the surrounding frame structure a series of nylon bumper stops  64 . These stops may typically engage the plates  56  when the pneumatic bladders  60  are actuated, effectively limiting the vertical movement of the plates  56  and the discharge valve  10 . 
         [0028]    In operation, the discharge valve  10  normally assumes the closed position shown in  FIG. 4A . In this case, the discharge valve  10  seats in the opening of the hopper  30  and prevents bulk material flow from flowing downwardly through the lower opening in the hopper. To actuate the discharge valve  10  the pneumatic bladders  60  are inflated by well known conventional means. This causes the transfer hopper to move from the position shown in  FIG. 4A  to the position shown in  FIG. 4B . This effectively opens the opening  32  within the hopper  30 . See  FIG. 4B . Now the bulk material or powder disposed within the hopper can flow downwardly past the discharge valve  10  into and through the underlying opening  32  in the hopper  30 . Because of the particular shape of the upper portion of the discharge valve  10 , the flow of powder, bulk material or other particles is greatly facilitated. 
         [0029]    The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.