Abstract:
A converter converts an existing bulk bag unloader to a bulk cargo receiver that eliminates the use of bulk bags. The converter enables the unloader to receive a continuous feed of bulk cargo without any interruptions such as those needed to unload emptied bulk bags and reload the unloader with full bulk bags.

Description:
FIELD 
       [0001]    The field of this disclosure is flexible intermediate bulk container or bulk bag unloaders. In particular, the field of this disclosure is a method of converting an existing bulk bag unloader to a bulk cargo receiver that eliminates the use of bulk bags. 
       BACKGROUND 
       [0002]    A flexible intermediate bulk container (FIBC) or a bulk bag is a large container of flexible fabric that is used to store and transport heavy loads of flowable products such as seeds, nuts, sand, fertilizer and granules or pellets of plastic. The bags are constructed with woven polypropylene or other equivalent fabrics, and often have a large opening at their top and a spout that can be closed at their bottom. A typical bulk bag can be dimensioned to hold approximately 50 cubic feet of bulk cargo. A typical bulk bag is constructed with four heavy duty strap loops that are positioned at four corners of the bag around the top opening of the bag. A bulk bag filled with bulk cargo can be lifted and transported by a forklift with the forks of the forklift each passing through pairs of adjacent strap loops of the four strap loops. A bulk bag filled with bulk cargo can also be transported by being positioned on a pallet that is lifted by a forklift. 
         [0003]    The bulk cargo transported in a bulk bag is unloaded from the bulk bag by a bulk bag unloader.  FIG. 1  is a representation of a typical unloader  10 . The unloader  10  has a rigid, stationary framework  12  supporting the component parts of the unloader  10 . A hopper  14  is supported by the framework  12  at a bottom of the unloader. A rail  16  is supported by the framework  12  at a top of the unloader. The rail  16  extends over the top of the hopper  14  and over an area adjacent the hopper  14 . 
         [0004]    A trolly  22  having a hoist  24  is provided on the rail  16 . The trolly  22  is moveable on the rail  16  from one end of the rail  16  where the hoist  24  is positioned adjacent the hopper  14  to an opposite end of the rail  16  where the hoist  24  is positioned above the hopper  14 . 
         [0005]    A cable  26  extends downwardly from the hoist  24 . The bottom of the cable  26  is connected to an X-shaped lifting member  28 . The lifting member  28  has four arms  32  with hooks  34  at the distal ends of the arms. 
         [0006]    A conveyor  36  is positioned beneath the hopper  14 . The conveyor  36  receives bulk cargo dispensed from the hopper  14  and conveys the bulk cargo away from the unloader  10 . 
         [0007]    In operation of the bulk bag unloader  10 , a bulk bag  38  containing bulk cargo is first positioned adjacent the hopper  14  of the unloader  10 . The hoist  24  is then operated to lower the X-shaped lifting member  28 . The lifting member  28  is lowered a sufficient distance to enable the four strap loops on the bulk bag  38  to be engaged in the four hooks  34  of the lifting member  28 . Engaging the four strap loops  40  of the bulk bag  38  in the four hooks  34  attaches the bulk bag to the lifting member  28  of the bulk bag unloader  10 . 
         [0008]    The hoist  24  is then operated to retract the cable  26  and lift the bulk bag  38  suspended by its four strap loops  40  from the lifting member  28 . The bulk bag  38  is raised a sufficient distance to position the bulk bag above the top of the hopper  14 . The trolley  22  is then operated to move the lifted bulk bag  38  from its position adjacent the hopper  14  to a position of the bulk bag  38  over the hopper  14 . 
         [0009]    With the bulk bag  38  positioned over the hopper  14 , the spout at the bottom of the bulk bag can then be opened. Opening the spout allows the bulk cargo contained in the bulk bag  38  to pour from the spout and into the top of the hopper  14 . When all of the bulk cargo has exited the bulk bag  38  into the hopper  14 , the trolley  22  is then operated to move the emptied bulk bag  38  from its position over the hopper  14  to a position adjacent the hopper  14 . The hoist  24  is then operated to lower the emptied bulk bag  38  a sufficient distance to enable the strap loops  40  of the emptied bulk bag  38  to be removed from the four hooks  34  of the lifting member  28 . The process of attaching a bulk bag  38  containing bulk cargo to the lifting member  28 , and then moving the bulk bag  38  containing bulk cargo to a position over the hopper  14  where the bulk bag  38  can be emptied is repeated. 
         [0010]    It can be appreciated that the above described repeated sequences of unloading bulk cargo from bulk bags to a hopper is significantly time consuming. 
         [0011]    There are existing continuous bulk cargo unloaders that use vacuum pressure to draw a stream of bulk cargo to a hopper which then dispenses the bulk cargo to a conveyor. However, removing an existing bulk bag unloader from its location and replacing it with a new continuous bulk cargo unloader can be very expensive. 
       SUMMARY 
       [0012]    The method of this disclosure that converts an existing bulk bag unloader to a bulk cargo receiver overcomes the disadvantage of the significant time required to repeatedly unload bulk cargo from bulk bags to a hopper. The method basically replaces the bulk bags that are unloaded by a bulk bag unloader such as that described earlier. Additionally, the method does not require that the existing bulk bag unloader be entirely replaced, but makes use of the existing unloader. This significantly reduces the cost of the conversion. 
         [0013]    The method involves assembling a converter to an existing bulk bag unloader. The converter includes a rigid tank that is attached to the framework of the existing unloader and is supported by the framework of the unloader. The tank has at least one side wall that extends around an interior volume of the tank. The tank has a top opening at a top end of the at least one side wall of the tank and a bottom opening at a bottom end of the at least one side wall of the tank. The tank is suspended by the lifting member and hoist of the existing unloader over the hopper of the existing unloader. The interior volume of the tank is communicated through the bottom opening of the tank with the interior volume of the hopper through the top opening of the hopper. 
         [0014]    A tube is attached to the tank. The tube has a length with opposite proximal and distal ends and an interior bore that extends through the length of the tube. The proximal end of the tube is connected to the tank. A proximal end opening of the tube communicates the interior bore of the tube with the top opening of the tank and the interior volume of the tank. The distal end of the tube is configured for communication with bulk cargo. A distal end opening of the tube communicates the bulk cargo with the interior bore of the tube. The bulk cargo could be contained in a silo, a rail car, day bins, box tippers, drums or other equivalent means of containing bulk cargo. 
         [0015]    A vacuum source is connected to the tank and communicates with the interior volume of the tank. The vacuum source is operable to create a vacuum pressure in the interior volume of the tank. The vacuum pressure is communicated to the interior bore of the tube and to the distal end of the tube where the distal end opening of the tube is communicated with the bulk cargo. The vacuum pressure draws the bulk cargo through the distal end opening of the tube, through the interior bore of the tube, through the proximal end opening of the tube, through the top opening of the tank and into the interior volume of the tank. The bulk cargo in the interior volume of the tank is fed or dropped by gravity through the bottom opening of the tank, through the top opening of the hopper and into the interior volume of the hopper. From the interior volume of the hopper, the bulk cargo drops through the bottom opening of the hopper to the conveyor below the bottom opening of the hopper. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Further features of the method of converting an existing bulk bag unloader to a bulk cargo receiver are set forth in the following detailed description of the method and the drawing figures. 
           [0017]      FIG. 1  is a representation of the construction of a typical bulk bag unloader. 
           [0018]      FIG. 2  is a representation of a perspective view of the method of converting the existing bulk bag unloader to a bulk cargo receiver using the converter of this disclosure. 
           [0019]      FIG. 3  is a representation of the existing bulk bag unloader of  FIG. 1  with the converter of this disclosure being assembled to the bulk bag unloader. 
           [0020]      FIG. 4  is a representation of the existing bulk bag unloader that has been modified with the converter of this disclosure. 
           [0021]      FIG. 5  is a representation of a flow chart of the method of this disclosure. 
       
    
    
     DESCRIPTION 
       [0022]    Referring to  FIGS. 3 and 4 , the method of converting an existing bulk bag unloader  10 ′ to a bulk cargo receiver using the converter  42  of this disclosure is shown. The existing bulk bag unloader  10 ′ has the same construction as the bulk bag unloader  10  described earlier and therefore will not again be described in detail. The component parts of the bulk bag unloader  10 ′ shown in  FIGS. 3 and 4  are labeled with the same reference numbers used in describing the construction of the bulk bag unloader  10  of  FIG. 1 , with the reference numbers being followed by a prime (′). 
         [0023]      FIG. 2  shows a representation of the converter  42  used in the method of this disclosure. As stated earlier, the converter  42  basically replaces the bulk bags that are unloaded by a bulk bag unloader. The converter  42  enables a continuous feed or flow of bulk cargo to the converter  42 . That continuous flow of bulk cargo is then delivered by the converter  42  to the hopper of the existing bulk bag unloader  10 ′. This method does not require that the existing unloader be entirely replaced with a continuous bulk cargo receiver, but makes use of the existing bulk bag unloader. This significantly reduces the cost of the conversion. 
         [0024]    The converter  42  includes a tank  44 . The tank  44  is constructed of rigid material, for example steel or stainless steel. Other equivalent materials could be employed in constructing the tank  44 . The tank  44  has at least one side wall  46  that extends around a hollow interior volume  48  of the tank. The side wall  46  gives the tank  44  a general cylindrical configuration. However, the tank  44  could be constructed with other equivalent configurations. The at least one side wall  46  of the tank  44  has a lower portion  52  having a general conical shape. The tank lower portion  52  tapers as it extends downwardly to a circular bottom opening  54  at a bottom end of the at least one side wall  46 . The tank has a circular top opening  56  at the top end of the at least one side wall  46  of the tank. 
         [0025]    An outlet pipe  58  is attached to the bottom of the tank  44 . The outlet pipe  58  has a cylindrical configuration and a hollow interior bore  60  that communicates with the interior volume  48  of the tank  44  through the bottom opening  54  of the tank  44 . The outlet pipe  58  has a flexible portion  62  at a bottom end of the outlet pipe. 
         [0026]    An inlet tube  68  is connected to the at least one side wall  46  of the tank  44 . As represented in  FIG. 2 , the inlet tube  68  is connected to the at least one side wall  46  adjacent the top opening  56  of the tank  44  and at an orientation that is generally tangent to the at least one side wall. 
         [0027]    A supply tube  72  is connected to the inlet tube  68 . The supply tube  72  has a length with opposite proximal  74  and distal  76  ends and an interior bore that extends through the length of the tube. The supply tube proximal end  74  is connected to the inlet tube  68  of the tank  44 . The supply tube proximal end  74  has a proximal end opening that communicates through the inlet tube  68  with the interior volume  48  of the tank  44 . The distal end  76  of the supply tube  72  has a distal end opening. The distal end opening of the supply tube  72  is configured for communication with bulk cargo  86 . The distal end  76  of the supply tube  72  has a flexible portion that facilitates communication with the bulk cargo  86 . The bulk cargo  86  is represented schematically in  FIG. 2 . The bulk cargo  86  could be contained in a storage silo, in a rail car, in day bins, and box tippers, in drums or other equivalent means of containing, storing and transporting bulk cargo. 
         [0028]    A domed shaped cover  88  is attached over the top opening  56  of the tank  44 . The cover  88  is secured to the top end of the at least one side wall  46  of the tank  44 . The domed shape of the cover  88  encloses the interior volume  48  of the tank  44 . The cover  88  could have another equivalent configuration to the dome shape represented in the drawing figures. 
         [0029]    An outlet tube  90  is connected to the cover  88 . As represented in  FIG. 2 , the outlet tube  90  is connected to the domed shaped cover  88  adjacent a peripheral edge of the cover  88  and at an orientation that is directed toward the center of the domed shaped cover  88  and the center of the tank  44 . 
         [0030]    A vacuum tube  92  is connected to the outlet tube  90  of the dome shaped cover  88 . The vacuum tube  92  has a length with opposite proximal  94  and distal  96  ends and an interior bore that extends through the length of the tube. The vacuum tube proximal end  94  is connected to the outlet tube  90  of the domed shape cover  88 . The vacuum tube proximal end  94  has a proximal end opening that communicates through the outlet tube  90  with the interior volume  48  of the tank  44 . The distal end  96  of the vacuum tube  92  is configured for communication with a vacuum source  98 . The vacuum source  98  is represented schematically in  FIG. 2 . The vacuum source  98  could be any type of vacuum source, for example a regenerative vacuum blower. The vacuum source  98  communicates through the vacuum tube  92  with the interior volume  48  of the tank  44 . 
         [0031]    A support structure  102  is attached to the tank  44 . The support structure  102  is constructed of metal angled pieces or other equivalent types of materials. As represented in  FIG. 2 , the support structure  102  has a plurality of horizontal members  104  that extend around the tank  44 . Additionally, the support structure  102  has a plurality of legs  106  that extend downwardly from the horizontal members  104  to a pair of unloader engaging members  108  at opposite bottom ends of the support structure  102 . The unloader engaging members  108  are configured for engaging with portions of a bulk bag unloader  10 ′ in assembling the converter  42  to the existing bulk bag unloader according to the method of this disclosure and supporting the tank  44  over the hopper  14 ′ of the unloader  10 ′. 
         [0032]    According to the method of this disclosure, four slings  112  are attached to four corners of the support structure  102  of the converter as represented in  FIG. 2 . The slings could be constructed as steel chains or other equivalent materials. The four slings  112  extend upwardly to four lifting rings  114  formed at the top ends of the slings. The lifting rings  114  are dimensioned to fit over the arms  32 ′ and into the hooks  34 ′ of the lifting member  28 ′ of the existing unloader  10 ′. 
         [0033]      FIGS. 3 and 4  are representations of the converter  42  being assembled to an unloader  10 ′ according to the method of this disclosure. Basically, the converter  42  is assembled to the unloader  10 ′ in much the same manner as the bulk bag  38  is assembled to the unloader  10  represented in  FIG. 1 . In the first step of the method of converting an existing bulk bag unloader a continuous bulk cargo receiver, the converter  42  is first positioned adjacent the hopper  14 ′ of the unloader  10 ′. This is represented in the first step  120  of  FIG. 5 . The trolley  22 ′ is then operated to move along the rail  16 ′ to a position over the converter  42 . This is represented in step  122  of  FIG. 5 . The hoist  24 ′ is then operated to lower the X-shaped lifting member  28 ′. The lifting member  28 ′ is lowered a sufficient distance to enable the four slings  112  of the converter  42  to be manually extended upwardly to reach the arms  32 ′ of the lifting member  28 ′. This is represented in the step  124  of  FIG. 5 . The lifting rings  114  at the distal ends of the four slings  112  are then positioned over the arms  32 ′ of the lifting member  28 ′ and are engaged with the hooks  34 ′ at the ends of the arms. Engaging the lifting rings  114  in the hooks  34 ′ attaches the converter  42  to the lifting member  28 ′ of the unloader  10 ′. This is represented in step  126  of  FIG. 5 . 
         [0034]    The hoist  24 ′ is then operated to retract the cable  26 ′ and lift the converter  42  suspended by the four slings  112  from the existing lifting member  28 ′. This is represented in  FIG. 3  and in step  128  of  FIG. 5 . The converter  42  is raised a sufficient distance to position the converter above the top of the hopper  14 ′ of the unloader  10 ′. The trolley  22 ′ is then operated to move the raised converter  42  from its position adjacent the hopper  14 ′ to a position of the converter  42  over the hopper  14 ′. This is represented in step  132  of  FIG. 5 . 
         [0035]    With the converter  42  positioned over the hopper  14 ′, the hoist  24 ′ is then operated to lower the converter  42 . The lowering of the converter  42  continues until the unloader engaging members  108  of the support structure  102  of the converter  42  engage on top of portions of the framework  12 ′ of the unloader  10 ′. This is represented in  FIG. 4  and in step  134  of  FIG. 5 . At this point, the framework  12 ′ of the unloader  10 ′ is supporting the converter  42  in a position above the hopper  14 ′. 
         [0036]    The flexible portion  42  of the outlet pipe  58  of the converter  42  is then communicated with a top opening of the hopper  14 ′. This is represented in step  136  of  FIG. 5 . This completes the method of converting the existing bulk bag unloader  10 ′ to a continuous bulk bag receiver. 
         [0037]    The distal end  76  of the supply tube  72  is then communicated with the bulk cargo  86 . This is represented in step  138  of  FIG. 5 . 
         [0038]    The vacuum source  98  is then operated to create a vacuum pressure in the interior volume  48  of the tank  44 . This is represented in step  142  of  FIG. 5 . The vacuum pressure is communicated from the interior volume  48  of the tank  44 , through the inlet tube  68 , through the proximal end  74  of the supply tube, through the interior bore of the supply tube and to the distal end  76  of the supply tube. 
         [0039]    The vacuum pressure at the supply tube distal ends  76  draws the bulk cargo  86  through the distal end  76  of the supply tube, through the interior bore of the supply tube, through the proximal end  74  of the supply tube, through the inlet tube  68  attached to the tank  44  and into the interior volume  48  of the tank. The bulk cargo drawn into the interior volume  48  of the tank is fed or dropped by gravity through the bottom opening  54  of the tank  44 , through the outlet pipe  58 , through the top opening of the hopper  14 ′ and into the interior volume of the hopper. This is represented in step  144  of  FIG. 5 . From the interior volume of the hopper  14 ′, the bulk cargo drops from the hopper to the conveyor  36 ′ below the bottom of the hopper. The conveyor  36 ′ then conveys the bulk cargo away from the unloader  10 ′. 
         [0040]    In the above manner, the conversion of the existing bulk bag unloader  10 ′ according to the method of the disclosure enables a continuous flow of bulk cargo  86  to the hopper  14 ′ without any interruptions such as those needed to replace an emptied bulk bag. 
         [0041]    As various modifications could be made in the method herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present disclosure should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.