Patent Publication Number: US-11656027-B2

Title: Biomass drying system and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application Ser. No. 62/992,731, filed on Mar. 20, 2020, the entire disclosure of which is hereby expressly incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     A biomass drying system and method. The system and method facilitates a continuous automated drying process. 
     BACKGROUND 
     Post-harvest drying is a key processing step in a number of crop production processes. For example, the moisture content of hemp as harvested can be as high as 80%-85%. If the harvested hemp improperly dries, the hemp can become contaminated by fungi or bacteria and become spoiled and unsuitable for food or medical processing. Conversely, drying hemp well can maximize the quality of food, medicine, or fiber products that can be realized from the harvest. Current drying systems and processes are imprecise, labor intensive, and/or not easily adapted to match the scale of the production. There is a need in the field for improved drying systems and methods. 
     SUMMARY 
     The present disclosure provides a system that facilitates the controlled drying of biomass. The system and method of the present disclosure provides automated control over the rate of drying and the moisture content of the resulting product. Some embodiments of the system and method also includes auto-loading and unloading, thereby providing a fully automated drying process. The system and method is easily adapted to match the scale of the production and therefore has applicability in large operations as well as micro operations. In addition, since the drying rate and moisture content of the material being dried is monitored and controlled, the system and method can be used to dry products for a wide range of different applications (e.g., drying hemp for medical use as well as for industrial use). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following Detailed Description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
         FIG.  1    is an isometric view of a biomass drying system of the present disclosure; 
         FIG.  2    is an isometric view of a component of the system of  FIG.  1   ; 
         FIG.  3    is the component of  FIG.  2    with a wall portion removed to show the internal structure of the component; 
         FIG.  4    is a schematic illustration of the flow of biomass through the component of  FIG.  2   ; 
         FIG.  5    is a schematic illustration of the component of  FIG.  2    fully loaded with biomass; 
         FIG.  6    is a side elevation view of the system of  FIG.  1   ; 
         FIG.  7    is a top view of the system of  FIG.  1   ; 
         FIG.  8    is a bottom view of the system of  FIG.  1   ; 
         FIG.  9    is a first end view of the system of  FIG.  1   ; 
         FIG.  10    is a second end view of the system of  FIG.  1   ; and 
         FIG.  11    is an isometric view of a component of the system of  FIG.  2   . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     Referring to the figures, a drying system according to an embodiment of the present disclosure is described in further detail. In the depicted embodiment, the drying system  10  includes a housing  12 . The housing  12  contains the material to be dried during the drying process. The material to be dried could be any number of materials including, for example, chopped up hemp. 
     In the depicted embodiment, the housing  12  includes a top  14 , a bottom  16 , and a side wall  18 . The side wall  18  extends between the top  14  and the bottom  16 . The housing  12  includes an upper portion  58 , a middle portion  60 , and a lower portion  62 . In the depicted embodiment, the housing  12  has a rectangular cube-like shape. It should be appreciated that many alternative housing configurations are possible. 
     In the depicted embodiment, the housing  12  also includes a material inlet  20 , a material outlet  22 , an air inlet  24 ,  26 , and air outlet  28 ,  29 . In the depicted embodiment, the material inlet  20  and the air outlets  28 ,  29  are located in the upper portion  58  of the housing  12 . In the depicted embodiment, the material outlet  22  and the air inlet  24 ,  26  are located in the lower portion  62  of the housing  12 . It should be appreciated that many alternative configurations are possible. For example it should be appreciated that he location and sizes of the air inlets and outlets can vary. For example, in an alternative embodiment the housing may including a single air outlet on the upper portion as opposed to the air outlets  28 ,  29 . 
     The drying system  10  of the depicted embodiment includes a blower  30  configured to blow air into the air inlet  24 ,  26 . In the depicted embodiment, the blower  30  is a heater and blower combination that is configured to deliver forced heated air to the housing  12 . In the depicted embodiment, the air inlet  24 ,  26  includes a first air inlet  24  and a second air inlet  26 . In the depicted embodiment, both the first and second air inlets  24 ,  26  are located in the lower portion  62  of the housing  12 . The drying system  10  of the depicted embodiment includes a loading conveyer  32  configured to load material into the housing  12  and an unloading conveyer  34  configured to move material out of the housing  12 . The drying system  10  of the depicted embodiment includes a moisture sensor  36  positioned within the housing  12  to monitor the moisture content of the biomass material in the housing  12 . It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the drying system  10  further includes an electronic control unit and a user interface. An operator can program the drying system  10  to continue to fill the housing  12  and output dried material at a particular target moisture content. If the operator desires that the material be dried faster, the operator can program the blower  30  to force more air into the housing  12  and/or increase the temperature of the air forced into the housing  12 . It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the housing  12  includes a first air inlet chamber  38  and a second air inlet chamber  40 . Each of the chambers  38 ,  40  defines an open air space in the housing  12  that remains open during normal drying operation when material is being housed and moved through the housing  12 . In the depicted embodiment, the first and second air inlet chambers  38 ,  40  are separate discrete areas in the housing  12 . In the depicted embodiment, the first and second air inlet chambers  38 ,  40  are located on opposite sides of the housing  12 . It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the first air inlet chamber  38  is adjacent the first air inlet  24  and the second air inlet chamber  40  is adjacent the second air inlet  26 . The first and second air inlet chambers  38 ,  40  are configured to allow air to flow into and out of the air inlet chambers  38 ,  40 . In the depicted embodiment, the first air inlet chamber  38  is at least partially defined by a first lower material deflector member  44 . In the depicted embodiment, the second air inlet chamber  40  is at least partially defined by a second lower material deflector member  46 . In the depicted embodiment, the first and second lower material deflector members  44 ,  46  are perforated metal walls that deflect material away from the air inlets  24 ,  26  so that the material does not block the first and second air inlets  24 ,  26 . As discussed above, the lower material deflector members  44 ,  46  define the first and second air inlet chambers  38 ,  40  in the housing  12 . In the depicted embodiment, the bottom  16  of the housing  12  is a solid wall that partially defines the first air inlet chamber  38  and the second air inlet chamber  40  in the housing  12 . It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the first and second lower material deflector members  44 ,  46  direct the material in the housing  12  (e.g., chopped up hemp) downwardly towards the material outlet  22 . The first and second lower material deflector members  44 ,  46  form a V-shaped funnel that funnels the material in the housing  12  out of the housing  12 . The depicted configuration leverages gravity to generate and maintain material flow in the housing  12 . In the depicted embodiment, the material outlet  22  is rectangular with two opposed short edges  74 ,  76  and two opposed long edges  78 ,  80 . In the depicted embodiment, a conveyer  90  is positioned at the material outlet  22  and configured to convey material out of the housing  12  at a controlled rate. In the depicted embodiment, the opposed long edges  78 ,  80  are coincident with the lower edges of the first and second lower material deflector members  44 ,  46 . When material is conveyed out of the housing  12  through the material outlet  22 , the material in the housing  12  settles downwardly opening up more space at the top  14  of the housing  12  to receive more material. In the depicted embodiment, the moisture content of the material near the material outlet  22  is monitored and controlled. The flow rate of material out of the housing  12  is in part determined by the moisture content of the material near the material outlet  22 . It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the housing  12  includes a center chamber  42  within the housing  12  located in a central portion of the housing  12 . The center chamber  42  is configured to allow air flow into and out of the center chamber  42 . In the depicted embodiment, the center chamber  42  is at least partially defined by a material deflector  48 . In the depicted embodiment, the material deflector  48  defines a roof shape. In the depicted embodiment, the material deflector  48  includes a first angle side  64  and a second angle side  66 . In the depicted embodiment, the angled sides  64 ,  66  are connected at an apex  68 . In the depicted embodiment, the apex  68  defines a 30 to 120 degree angle (e.g., 45 degrees). In the depicted embodiment, the material deflector  48  is positioned in the middle portion  60  of the housing  12  with the apex  68  located directly below the material inlet  20  of the housing  12 . The material deflector  48  maintains a central open air space (center chamber  42 ) in the middle portion  60  of the housing  12  and splits the inflow of material from the material inlet  20  to a first side  70  of the housing  12  and a second side  72  of the housing  12 . In the depicted embodiment, the material deflector  48  is constructed of a perforated metal sheet. In the depicted embodiment the perforated metal sheet includes an array of holes having a dimeter of 0.15 inches. See, for example,  FIG.  11   . 
     The material deflector  48  separates the material in the housing  12  into two sides that each receive forced air from the respective first and second air inlets  24 ,  26  below. It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, the housing  12  includes a first upper corner air chamber  50  and a second upper corner air chamber  52 . Each of the first and second upper corner air chambers  50 ,  52  are partially defined by a perforated wall  54 ,  56 . In the depicted embodiment, the top  14  of the housing  12  at least partially defines the first upper corner air chamber  50  and the second upper corner air chamber  52  in the housing  12 . The upper corner air chambers  50 ,  52  provide an air flow path and prevents buildup of material in the upper corners. It should be appreciated that many alternative configurations are possible. 
     In the depicted embodiment, a method of drying biomass such as hemp is provided. The method includes the steps of auto-loading hemp into a hopper (e.g., housing  12 ), blowing air into the hopper, monitoring the moisture content of the hemp near an outlet of the hopper, auto unloading hemp from the hopper based on the sensed moisture content, and auto-loading the hopper to maintain a particular volume of hemp in the hopper. The blown-in air is directed from an air inlet through the hemp in the hopper top air outlet. It should be appreciated that many alternative steps are possible. 
     The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.