Patent Abstract:
A blueberry drying apparatus is disclosed that includes a longitudinally extending produce conveyer and a drying chamber through which the conveyer passes. The conveyer belt is constructed of a wire mesh, which allows air flow through the conveyer. The drying chamber includes two separate sets of fans. One set of fans is mounted above the conveyer and blows air directly onto the berries carried atop the conveyer. The other set of fans is mounted below the conveyer and draws air through the conveyer and around the berries.

Full Description:
This invention relates to an apparatus for drying small produce, and specifically an apparatus for drying blueberries in an automated packaging process. 
   BACKGROUND OF THE INVENTION 
   Moisture on blueberries in the form of a watery film or water droplets is a significant problem for blueberry processors. Blueberries have a smooth skin with a waxy coating or bloom, which tends to hold moisture to the berry&#39;s skin. Moisture on the berries attracts and holds mold, yeast and bacteria, which results in spoilage. Since blueberries are typically cleaned and sanitized in a water bath or with a spray bar, the berries must be dried before packaging or further processing in order to minimize spoilage. Conventional blueberry drying apparatus use an array of fans to blow air onto the bulk blueberries carried atop a conveyer. While most drying apparatus employ high velocity fans and blowers, the air flow created by these dryers fail to complete dry the berries and simply blow the water droplets to the bottom side of the berries. 
   SUMMARY OF THE INVENTION 
   The present invention seeks to improve the airflow over the berries to facilitate the drying process. The blueberry dryer embodying the present invention includes a longitudinally extending produce conveyer and a drying chamber through which the conveyer passes. The conveyer belt is constructed of a wire mesh, which allows air flow through the conveyer. The drying chamber includes two separate sets of fans. One set of fans is mounted above the conveyer and blows air directly onto the berries carried atop the conveyer. The other set of fans is mounted below the conveyer and draws air through the conveyer and around the berries. The use of two sets of drying fans promotes tighter laminar airflow around the berries. In addition, the baffles inside the drying bay direct and channel the airflow from the fans and reduce turbulence which increases the volume of air moving around the berries through the conveyer. The present invention also includes a vibrator mechanism that vibrates the transport conveyer to shake the water droplets from the bottom of the berries. 
   Theses and other advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings illustrate an embodiment of the present invention in which: 
       FIG. 1  is a perspective view of an embodiment of the invention; 
       FIG. 2  is a front end view with portions cut way of the embodiment of  FIG. 1  without the hopper shown; 
       FIG. 3  is a simplified side sectional view of the conveyer, fans and vibrators of the embodiment of  FIG. 1 ; and 
       FIG. 4  is a simplified side view illustrating the laminar airflows around a blueberry facilitated by the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings, a blueberry drying apparatus, or simply “dryer” is designated generally as reference numeral  10 . Dryer  10  includes a long drying chamber  40  and a produce conveyer  30  that extends longitudinally through the drying chamber. Conveyer  30  and drying chamber  40  are built on a table like frame  20 , which includes two elevated side members  22  supported by eight upright legs  23 . Frame  20  also includes various other beams, braces and supports to provide sufficient structural integrity to dryer  10 . 
   Conveyer  30  is formed by a conveyer belt  31 , which is trained about a plurality of traverse rollers and longitudinal rails mounted between side members  22 . Conveyer belt  31  is constructed of a flexible stainless steel wire mesh, which allows airflow through the conveyer. While, conveyer belt  31  is illustrated with a wire mesh construction, any conveyer belt which allows air to pass therethrough may be employed. Drive rollers  32  are mounted at opposite ends of side members  22  and are operably connected to a variable speed electric motor  34  by a gear box, belt drive or other drive means. Each drive roller  32  has a toothed gear  33  at opposite ends of the roller, which mates with conveyer belt  31 , so that rotation of the drive rollers  32  propels the conveyer belt  31  along the length of the conveyer. A tension roller  35  is shiftably mounted to frame  20  so that the tension of conveyer belt  31  can be adjusted. 
   Four paddle vibrators  54  are transversely mounted between side members  22  just below the top conveyer run. Each paddle vibrator  54  consists of a flat elongated paddle operatively connected to an electrical drive motor, which rotates the paddles about their longitudinal axises. When rotated, paddle vibrators  54  intermittently contact conveyer belt  31  to impart a slight vibration through the conveyer belt to berries  2 . Typically, each paddle vibrator  54  is powered by one or more variable speed electric motor, which can be selectively controlled to vary the amount of vibrations generated. 
   Drying chamber  40  has an internal drying bay  41  defined by two sidewalls  24 , which extend vertically from side members  22 . Each sidewall  24  has a window  25  therein. Drying chamber  40  includes three upper drying fans  42 , two lower drying fans  4  and a high velocity blower  46 . As shown, upper fans  42  are suspended over conveyer  30  and lower fans  44  are suspended below conveyer  30 . Fans  42  and blower  46  are mounted atop the open drying chamber  40  to cross members  28  that extend transversely between side walls  24 . Fans  44  are mounted between side members  22 . As shown, drying fans  42  and  44  are staggered longitudinally with respect to one another. Drying fans  42  and  44  both generate vertical air flows with fans  42  blowing air downward through conveyer  30  and fans  44  drawing air vertically through the conveyer. Typically, drying fans  42  and  44  are conventional electric powered axial or propeller fans, but any type of fan may be employed within the scope of this invention. Blower  46  is mounted above conveyer  30  at the front of drying bay  41 . Blower  46  is illustrated as a conventional radial fan, but again any suitable type of fan may be employed within the scope of this invention. Drying chamber  40  also includes four longitudinal baffles  50 , which extend the length of drying bay  41  and three lateral baffles  52 , which extend the width of the drying bay. Baffles  50  and  52  reduce turbulence within drying bay  41  and direct the air flow downward through conveyer belt  31 . 
   It should be noted that dryer  10  is designed to be used as a stand alone unit or as a component unit in an automated conveyer driven packaging system for drying bulk blueberries prior to packaging in individual containers. As part of an automated unit or system, typically all of the electrical drive motors of dryer  10  (conveyer, vibrators, fans and blowers motors) are wired to conventional electrical controller (not shown). While the electrical controller is not illustrated or described herein, such controllers are well known in the industry. 
   In operation, berries  2  are metered onto the top run of conveyer  30  from a hopper  6  located at the front of dryer  10 . Conveyer  30  carries the berries through drying bay  41  from one end of dryer  10  to the other. Paddle vibrators  54  initially help spread berries  2  across the width of the top run of conveyer  30 . More importantly, paddle vibrators  54  gently vibrate berries  2  to shake the water droplets  4  from the bottoms of the berries and continually turn the berries as they move through drying bay  41 . Blower  46  provides the initial high velocity air flow to remove the largest water droplets  4  from berries  2 . Within drying bay  41 , drying fans  42  and  44  complete the drying process by simultaneously blowing air downward onto the tops of berries  2  and drawing air from the bottom of the berries. Drying fans  42  blow cool ambient air through conveyer belt  31  onto berries  2 . Drying fans  44  pull air through conveyer belt  31  around berries  2 , which facilitates a tighter laminar airflow around the individual berries. Facilitating tighter laminar airflow around the berries whisks more moisture off the berries and improves evaporation. Baffles  50  and  52  help direct and channel the airflow from drying fans  42  downward onto berries  2  and reduce turbulence within drying bay  41 . At the end of dryer  10 , conveyer  30  deposits the newly dried berries having emerged from drying chamber  40  into a collection bin  8  or some other conveyer or processing equipment as desired for the processing system. 
   ADVANTAGES 
   One skilled in the art will note that the present invention has several advantages over conventional dryers. The use of two sets of drying fans promotes tighter laminar airflow around the berries. In addition, the baffles inside the drying bay direct and channel the airflow from the fans and reduce turbulence which increases the volume of air moving around the berries through the conveyer. By improving air flow around the berries through the conveyer, the present invention improves the drying process. The paddle vibrators gently vibrate the berries to shake the water droplets from the bottom of the berries, which significantly improves the drying process. 
   The embodiment of the present invention herein described and illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is presented to explain the invention so that others skilled in the art might utilize its teachings. The embodiment of the present invention may be modified within the scope of the following claims.

Technology Classification (CPC): 5