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.
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.
The bulk cargo transported in a bulk bag is unloaded from the bulk bag by a bulk bag unloader.
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.
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.
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.
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.
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.
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.
It can be appreciated that the above described repeated sequences of unloading bulk cargo from bulk bags to a hopper is significantly time consuming.
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.
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.
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.
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.
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.
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.
Referring to
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.
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.
An inlet tube 68 is connected to the at least one side wall 46 of the tank 44. As represented in
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
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.
An outlet tube 90 is connected to the cover 88. As represented in
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
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
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
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
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
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
The distal end 76 of the supply tube 72 is then communicated with the bulk cargo 86. This is represented in step 138 of
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
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
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.
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.