Abstract:
A vibrating fluid bed dryer includes a first dryer stage including a first fluid bed air distribution plate mounted therein, and also includes a first air inlet. A a second dryer stage that includes a second fluid bed air distribution plate mounted therein is positioned to receive material from the first dryer stage. The second dryer stage includes a second air inlet. A drive assembly is coupled to vibrate the first dryer stage and the second dryer stage. The first dryer stage may be coupled to a source of cooling air and the second dryer stage may be coupled to a source of warming air, or vice-versa, or both dryer stages may be coupled to a source or warming air or cooling air.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of provisional application no. 62/168,660 filed on May 29, 2015. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to vibratory fluid bed processing equipment. 
       BACKGROUND 
       [0003]    Fluid bed processors dry, moisturize, heat, or cool bulk solid material by causing the material to vibrate on a screen or perforated surface within a rising column of heated, chilled, or moisturized air. Typical applications include sifting, scalping, classifying, de-dusting and de-lumping of dry bulk solids, or dewatering of solids-laden slurries. 
         [0004]    Current designs of circular vibrating fluid bed dryers are generally limited to about a seven-foot diameter in order to achieve higher rates. Current designs of circular vibrating fluid bed dryers require a separate second cooling unit to cool the material after drying. This second, separate unit, requires more headroom and plot space and a second set of drive motors. 
       SUMMARY 
       [0005]    Embodiments disclosed herein provide a second stage below a first dryer stage and still only use one drive. This eliminates the need for a separate second dryer or cooler, a second set of drive motors, less plot space, less head room, and requires less overall cost. In the past, larger diameter or multiple dryers and/or coolers were used to increase the dryer or cooling capacity. The circular vibrating fluid bed disclosed herein is unique with an internal back mixing capability. 
         [0006]    In one aspect, a vibrating fluid bed dryer comprises a first dryer stage including a first fluid bed air distribution plate mounted therein, and includes a first air inlet. A second dryer stage including a second fluid bed air distribution plate mounted therein is positioned to receive material from the first dryer stage. The second dryer stage includes a second air inlet. A drive assembly is coupled to vibrate the first dryer stage and the second dryer stage. 
         [0007]    The foregoing apparatus permits a variety of configurations to achieve a variety of material processing purposes. The first dryer stage may be coupled to a source of cooling air, while the second dryer stage is coupled to a source of warming air. Alternatively, the first dryer stage may be coupled to a source of warming air while the second dryer stage is coupled to a source of cooling air. In other configurations, the first dryer stage and the second dryer stage are both coupled to a source of cooling air, or to a source of warming air. 
         [0008]    The vibrating fluid bed dryer as set forth above may have a first dryer stage and second dryer stage that are substantially circular in shape and are in a stacked configuration. In other embodiments, the first dryer stage and the second dryer stage may be substantially rectangular in shape, or one stage may be circular and the other rectangular. 
         [0009]    In other embodiments, the first dryer stage includes a product outlet with an adjustable weir to control the flow of product through the product outlet and the second dryer stage is positioned beneath the first dryer stage to receive product from the product outlet by way of a product inlet. The second dryer stage may also include a product outlet with an adjustable weir to control the flow of product through the product outlet. The second dryer stage may also be removably mounted. 
         [0010]    Additional aspects related to the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the description, or may be learned by practice of the invention. Aspects of the invention may be realized and attained by means of the elements and combinations of various elements and aspects particularly pointed out in the following detailed description and the appended claims. It is to be understood that both the foregoing and the following descriptions are exemplary and explanatory only and are not intended to limit the claimed invention or application thereof in any manner whatsoever. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The accompanying drawings, which are incorporated in and constitute a part of this specification exemplify the embodiments of the present invention and, together with the description, serve to explain and illustrate principles of the inventive techniques. Specifically: 
           [0012]      FIG. 1  illustrates an embodiment of a vibratory processor employing the principles of the invention. 
           [0013]      FIG. 2  illustrates an embodiment of a multi-spout spacing frame of the processor of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In the following detailed description, reference will be made to the accompanying drawing(s), which show by way of illustration, and not by way of limitation, specific embodiments and implementations consistent with principles of the present invention. These implementations are described in sufficient detail to enable those skilled in the art to practice the invention and it is to be understood that other implementations may be utilized and that structural changes and/or substitutions of various elements may be made without departing from the scope and spirit of present invention. The following detailed description is, therefore, not to be construed in a limited sense. 
         [0015]      FIG. 1  illustrates an embodiment of a circular vibratory processor  5  employing the principles of the invention. A cylindrical housing comprising a plurality of components described herein, and generally designated  10 , is covered by a cover  12 . Material is fed into the housing  10  via material inlet port  14  onto the center of fluid bed media (referred to more generically as a fluid bed air distribution plate)  16 . The cover  12  has an opening, for air outlet (exhaust)  18 . The cover  12  is attached to spacing frame  20  which has a product outlet  22  by which material fed into the housing  10  via inlet port  14  exits. An adjustable weir  24  permits adjustment of the bed depth which controls residence time of the material within the spacing frame  20 . 
         [0016]    Fluid bed air distribution plate  16  is mounted to the spacing frame and permits air to pass through but not the material. The fluid bed air distribution plate  16  is installed between the spacing frame and the air inlet frame. Clamps and a gasket, seen generally at  26  and  27 , are used to clamp the spacing frame  20  to an upper air inlet frame  28 . The upper air inlet frame  28  has a spout  30 , which permits outside air to enter the housing  10  via the upper air inlet frame  28 . The fluid bed air distribution plate  16  may include a variety of different sizes of holes, or include mesh or a screen to permit different rates and types of air flow through the plate. 
         [0017]    In the lower portion of the housing  10 , multi-spout frame  32  is attached to the upper air inlet frame  28  via clamps seen generally at  34  and  36 . A product intake spout  38  on the multi-spout frame  32  accepts material that exits the product outlet  22 . The product intake spout  38  has an inclined chute, which directs the material received from the product outlet to lower fluid bed  40 . Air exhaust  42  permits outward flow of air. Product outlet  49  on the multi spout frame  32  permits discharge of product from the housing  10 . The lower fluid bed  40  is clamped between the multi spout frame  32  and lower air inlet frame  44  with clamps  46 ,  48 . An adjustable weir  50  permits adjustment of the bed depth, which controls residence time of the material within the multi-spout frame  32 . Air inlet  52  permits outside air to enter the housing via lower air inlet frame  44 . The lower end of air inlet frame  44  is attached to a drive plate  54  of drive assembly  56  by way of a plurality of clamps, two of which are shown at  58  and  60 . The drive plate  54  is attached on its lower surface to a plurality of springs  62 . This permits the portions above the drive plate  54 , in other words, the housing  10  to be suspended on springs  62  that allow the housing  10  to vibrate freely while minimizing power consumption and preventing vibration transmission to the floor. The drive assembly  56  is preferably equipped with one imbalanced-weight gyratory motor that creates multi-plane inertial vibration for the purpose of controlling the flow path of material on fluid bed media surfaces  16  and  40 . 
         [0018]      FIG. 1  also illustrates operation of the apparatus by showing material flow (solid arrows) and airflow (dotted arrows) through the apparatus  5 . Material enters onto the top fluid bed air distribution plate  16  through the opening  14  on the cover  12 . The drive system  56  causes vibration, typically in a circular motion, of the apparatus by way of a conventional motor. Moist exhausted air may be passed to a dust collector that separates the dust and moist air. Air entering the air inlets  30  or  52  may be heated or cooled and may be provided via a conventional source to enter the housing  10  and flow from the bottom of the fluid bed air distribution plate  16  or  40  up through the plate and into the spacing frame  20  (in the case of plate  16 ) or multi-spout frame  32  (in the case of plate  40 ). After heat exchange that occurs above the fluid bed air distribution plate  16 , the product is discharged from the top apparatus through the discharge spout  22  on the spacing frame  20 , and the moist exhaust air is emitted through the air outlet  18  on the cover  12 . 
         [0019]    The upper apparatus and the lower apparatus are clamped together in a manner to allow the product from the upper apparatus to enter the top of the fluid bed media  40  of the lower apparatus. The heating air or cooling air comes from the bottom of the fluid bed air distribution plate  40  though the lower air inlet frame  44 . After the heat exchange above the fluid bed air distribution plate  40 , the product will discharge from the lower apparatus though the discharge spout  49  on the multi-spout frame  32 , and the exhaust air is emitted from the air outlet  42  on the multi-spout frame  32 . 
         [0020]    The upper and lower portions, which may be fed by different sources of air, permit flexibility in operation of the apparatus. When heating air is introduced to both the top and bottom apparatus, the material will be dried two times, thereby increasing the dryer capacity. When cooling air is introduced to both the top and bottom apparatus, the material will be cooled two times, thereby increasing the cooling capacity. When heating air is introduced to the upper apparatus, and cooling air is introduced to lower apparatus, material will be dried first and then cooled, such as for packaging. When cooling air is introduced to the upper apparatus, and heating air is introduced to the lower apparatus, the material will be cooled first and then heated. This apparatus uses a small footprint, and can do multiple tasks. In contrast, conventional devices will have a large footprint or will use two separate apparatus to do the drying and cooling. 
         [0021]      FIG. 2  is a diagram of a preferred embodiment of the multi-spout spacing frame  32  shown in  FIG. 1 . The product intake spout is shown at  38  with an inclined chute. The air outlet is shown at  42 . Also seen in  FIG. 2  are inspection ports  70  and  72 . 
         [0022]    The circular vibrating fluid bed differs from a rectangular vibrating fluid bed as follows:
       The circular vibrating fluid bed has an internal backmixing (blending of wet and semi-dry feed materials in the center of the feed zone) capability and as a result can handle a wider range of wet feed material.   The dual deck unit is stacked one on top of the other and takes up less plot space while a rectangular unit is horizontal with the zones side by side   The circular vibrating fluid bed is fed in the middle while the rectangular unit is fed in the front of the unit.   The circular double deck fluid bed apparatus uses one drive assembly with two fluid bed decks clamped up and down together.       
 
         [0027]    The embodiment illustrated in  FIGS. 1 and 2  is inherently rigid and does not require heavy steel sidewalls or cross braces to withstand extensive vibration. Moreover, with no internal cross members, fewer seams and corners, such embodiments dramatically reduce cleaning time. Certain embodiments may feature lighter gauge shell and components, with fewer weld seams, and require only one air inlet and outlet resulting in lower material and labor costs—especially when finished to food, dairy, or pharmaceutical standards. Other embodiments may be frame-mounted with casters for low cost shipping, easy installation, and in-plant mobility. 
         [0028]    While a circular vibrating fluid bed has the advantageous characteristics as noted above, the upper apparatus or the lower apparatus may also be rectangular in shape and need not be circular. The apparatus can also be used to dedust or screen. A screen could replace the second stage cooler (or dryer). 
         [0029]    While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.