Abstract:
An apparatus is configured to control the distribution of tobacco strip in a charger of a tobacco packing press. The apparatus includes a housing. A plurality of ducts extend from the housing to the charger. Each duct is configured to direct a portion of the air flow from the housing to the charger. A plurality of nozzles are spaced around the perimeter of the charger. Each nozzle is connected to a corresponding one of the plurality of ducts. Each duct may include a flow controller that is selectively openable and closable to direct the portion of the air flow around a perimeter of the charger to distribute the tobacco strip in the charger. A method of controlling distribution of tobacco strip in a charger of a tobacco packing press includes providing an air flow and selectively directing portions of the air flow around a perimeter of the charger to distribute the tobacco strip in the charger.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an apparatus for controlling distribution of tobacco strip. The present invention also relates to methods of controlling distribution of tobacco strip. 
   2. Description of the Related Art 
   Vertically operating tobacco packing presses are used in tobacco processing to pack tobacco strip, or lamina, into containers, e.g. rectangular cases or cylindrical hogsheads. The container communicates at its top with an elongated, hollow, upright charger. The charger supports a column of tobacco strip extending upwardly from the container. Stationary chargers, vertically movable chargers and telescoping chargers are used. A vertically acting press ram having a press head is aligned above the charger so that the ram can be operated to force the press head downwardly through the charger to, or into, the container. Alternatively, the tobacco packing press may press the tobacco into a compression chamber, from where it is further forced into the container or a sleeve. With the press head raised, the tobacco strip is supplied into the top of the charger, for example by a conveyor positioned below the press head. The tobacco strip is supplied until the charger contains a predetermined quantity of loose uncompacted tobacco strip. The ram is then operated to force the press head downwardly through the charger and compress the entire quantity of tobacco into the container or the compression chamber. 
   It is desirable to evenly distribute the tobacco strip throughout the container to promote uniform aging of the tobacco and prevent degradation and breakage of the tobacco strip. Current tobacco packing presses include mechanical flaps or distributor blades that move back and forth or in a circular motion and are positioned near the top of the charger to distribute the flow of tobacco strip evenly into the charger. These mechanical systems may be unreliable and their effectiveness varies with the rate of tobacco strip flow into the charger. 
   SUMMARY OF THE INVENTION 
   It is an aspect of the present invention to provide an apparatus for controlling the distribution of tobacco strip that evenly distributes the tobacco strip. It is also an aspect of the present invention to provide a method of controlling the distribution of tobacco strip. 
   According to an aspect of the present invention, an apparatus for controlling distribution of tobacco strip in a charger of a tobacco packing press includes a housing configured to contain an air flow; a plurality of ducts extending from the housing to the charger, each duct being configured to direct a portion of the air flow from the housing to the charger; and a plurality of nozzles spaced around the perimeter of the charger, each nozzle being connected to a corresponding one of the plurality of ducts, wherein each duct includes a flow control device that is selectively openable and closable to direct the portion of the air flow into the charger to distribute the tobacco strip in the charger. 
   According to another aspect of the present invention, a method of controlling distribution of tobacco strip in a charger of a tobacco packing press includes providing a flow of air; and selectively directing portions of the flow of air around a perimeter of the charger to distribute the tobacco strip in the charger 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: 
       FIG. 1  depicts a plan view of an apparatus for controlling the distribution of tobacco strip in accordance with an embodiment of the present invention; 
       FIG. 2  depicts a perspective view of the apparatus of  FIG. 1 ; 
       FIG. 3  depicts a nozzle arrangement to control distribution of tobacco strip according to an embodiment of the present invention; and 
       FIG. 4  depicts a nozzle arrangement to control distribution of tobacco strip according to another embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1 and 2 , an apparatus  10  for distributing tobacco strip includes a housing  12 . The apparatus  10  may be provided in a tobacco processing plant or factory in which tobacco strip is delivered from redryers to tobacco packing presses  1 ,  2 . The housing  12  is configured to act as a plenum. The housing may contain a flow of air. For example, the housing may include a fan as the source of the air flow, or the housing  12  may be connected to an air flow source. The housing may also contain air that is pressurized to higher than ambient so as to provide a source of air flow from the housing  12 . A pump may be operatively connected to the housing to pump air into the housing, thus creating a pressure differential that provides an air flow from the housing  12 . 
   A duct  14  is connected to the housing  12  and forms an outlet from the housing for the air flow. It should be appreciated that as used throughout, the term “duct” may include any conduit, passage, or channel, of any cross sectional size and shape. It should also be appreciated that as used throughout, the term “duct” may include rigid or flexible conduits, passages or channels. 
   A Y-branch  16  is connected to the duct  14  and includes two ducts  18 ,  20  forming first and second flow paths. The Y-branch  16  may include a diverter  22  that is operable to divert the entire air flow into one duct of the Y-branch  16 . The diverter  22  may be pivotable in the direction shown by arrow A to either position shown in dotted lines. 
   The duct  18  may be connected to a Y-branch  24  that includes two ducts  26 ,  28 . The duct  26  may be connected to a Y-branch  30  that includes two ducts  32 ,  34 . The ducts  32 ,  34  may each include a flow control device  36 ,  38 , respectively that is operable to control the air flow through the duct  32 ,  34 . Each flow control device may be operable between two positions, a first position that permits full air flow through the duct and a second position that blocks air flow through the duct. The flow control device may be a solenoid operated damper. The duct  28  may be connected to a Y-branch  40  that includes ducts  42 ,  44 . The ducts  42 ,  44  may include flow control devices  46 ,  48 , respectively, in the same manner as the ducts  32 ,  34 . 
   The duct  20  may be connected to a Y-branch  50  that includes ducts  52 ,  54 . The duct  52  may be connected to a Y-branch  56  that includes ducts  58 ,  60 . Each duct  58 ,  60  may include a flow control device  62 ,  64 , respectively, in the same manner as the ducts  32 ,  34 ,  42 ,  44 . The duct  54  may be connected to a Y-branch  66  that includes ducts  68 ,  70 . Each duct  68 ,  70  may include a flow control device  72 ,  74 , respectively, in the same manner as ducts  32 ,  34 ,  42 ,  44 ,  58 ,  60 . 
   As illustrated in  FIG. 1 , the apparatus  10  may be configured to control distribution of tobacco strip in two tobacco packing presses, including a first tobacco packing press  1  and a second tobacco packing press  2 . The diverter  22  is pivoted to block air flow into duct  20  and permit air flow into duct  18 . The air flow may be further divided at Y-branch  24  and then further divided at Y-branches  30  and  40 . As tobacco strip is being delivered to the tobacco packing press  1 , the air flow from ducts  32 ,  34 ,  42 ,  44  may be controlled, as described in more detail below, to evenly distribute the tobacco strip in a charger of the first tobacco packing press  1 . While tobacco strip is being delivered to the first tobacco packing press  1 , the second tobacco packing press  2  may be attended to remove a container filled with packed tobacco strip and insert an empty container. 
   Once delivery of a predetermined quantity of tobacco strip to the first tobacco packing press  1  is completed, the diverter  22  may be pivoted to block air flow into duct  18  and permit air flow into duct  20 . Tobacco strip is delivered to the second tobacco packing press  2  and the air flow from ducts  58 ,  60 ,  68 ,  70  may be controlled to evenly distribute the tobacco strip to a charger of the second tobacco packing press  2 . The first tobacco packing press  1  may be attended to remove the filled container and insert an empty container. 
   Referring to  FIG. 3 , tobacco strip is delivered by a conveyor  76 . A funnel or hopper  78  may be positioned between the conveyor  76  and a charger  80  of the first tobacco packing press  1  to receive tobacco strip from the conveyor  76 . Positioned around the perimeter of the top of the charger  80  are nozzles  82 ,  84 ,  86 ,  88  that are connected to the ducts  30 ,  32 , 42 ,  44 . It should be appreciated that the ducts  30 ,  32 ,  42 ,  44  may be connected to the nozzles  82 ,  84 ,  86 ,  88  by flexible ducts, rigid ducts, or by a combination of flexible and rigid ducts. Although not illustrated in  FIG. 3 , it is understood that second tobacco packing press  2  also includes a charger having nozzles that are connected to ducts  58 ,  60 , 68 , 70 . It is also understood that the nozzles of the second tobacco packing press  2  may be connected to the ducts  58 ,  60 ,  68 ,  70  in a manner similar to that described for the first tobacco packing press  1 . 
   The distribution of tobacco strip in the charger  80  may be controlled by opening and closing the flow control devices  36 ,  38 ,  46 ,  48  in the ducts  32 ,  34 ,  42 ,  44  to evenly distribute the tobacco strip in the charger  80 . As used herein, the term “evenly distribute” refers to providing a predetermined quantity of uncompacted tobacco strip so that the umcompacted volume of tobacco strip has a substantially uniform density throughout. During filling of the charger  80 , the flow control devices  36 ,  38 ,  46 ,  48  may be opened and closed in a predetermined pattern to direct the tobacco strip evenly into all portions of the charger  80 . The opening and closing of the flow control devices may be controlled by a programmed logic controller (PLC)  90 . It should be appreciated that during filling of the charger of the second tobacco packing press  2 , the flow control devices  62 ,  64 ,  72 ,  74  in the ducts  58 ,  60 ,  68 ,  70  may be controlled in a manner similar to that described above with respect to the first tobacco packing press  1 . 
   The PLC  90  may be programmed to open and close the flow control devices in a predetermined pattern. The predetermined pattern may be dependent on a variety of parameters, including for example, the volume of air flow; the number, length, cross sectional size and shape of the ducts; the volume of tobacco strip flow; the range of size of the individual tobacco strips; the moisture content of the tobacco strip; the temperature of the air flow; and/or the size, shape and/or number of nozzles. It should be appreciated that other parameters may be considered. The PLC may also be configured to control the pivoting of the diverter  22 . 
   As shown in  FIG. 3 , the charger  80  has a rectangular cross section. The nozzles  84 ,  86  may be positioned on the side opposite the end of the conveyor and the nozzles  82 ,  88  may be positioned on opposite sides of the charger  80  on corresponding opposite sides of the conveyor  76  to control the distribution of the tobacco strip in the charger. The two nozzles  84 ,  86  may be positioned on the side opposite the end of the conveyor to maintain an even flow of tobacco strip into the charger  80 . 
   Referring to  FIG. 4 , a cylindrical charger  81  may be used to pack tobacco into a hogshead. The nozzles  82 ,  84 ,  86 ,  88  may be positioned around the perimeter of the charger  81  near the top of the charger  81 . The nozzles  84 ,  86  may be positioned opposite the end of the conveyor  76  to maintain an even flow of tobacco strip into the charger  81 . The axis of the nozzles  82  may be at an angle B to the centerline CL of the charger  81  and the conveyor  76 . The axis of the nozzle  88  may be at an angle C to the centerline CL. The axes of the nozzles  82  and  88  may be at an angle D with respect to each other. The axes of the nozzles  84 ,  86  may be at an angle E with respect to each other. In an embodiment of the present invention, the angles B, C, D may each be 120° and the angle E may be 38°. Although not shown in  FIG. 4 , it should be appreciated that a funnel or hopper may be placed between the conveyor  76  and the charger  81 . 
   It should be appreciated that the angular spacing of the nozzles may be dependent on a number of parameters. For example, the angular spacing of the nozzles may depend on the diameter of the charger, the speed of the conveyor and the flow rate of the tobacco strip, and/or the height of the charger. Other parameters may also be considered. In a manner similar to  FIG. 3  discussed above, the flow control devices may be opened and closed in a predetermined pattern to evenly distribute the tobacco strip in the charger. The PLC  90  may control the opening and closing of the flow control devices. The predetermined pattern may be dependent on a variety of parameters, including those discussed above with respect to  FIG. 3 . 
   Although two tobacco packing presses are shown in  FIG. 1 , it should be appreciated that the apparatus  10  may be configured to control the distribution of tobacco strip to any number of tobacco packing presses, including a single tobacco packing press. It should also be appreciated that although the control of the distribution of tobacco strip to the first and second tobacco packing presses has been described as sequential, the apparatus may be configured to control the distribution of tobacco strip to the packing presses simultaneously. In the event that the apparatus is configured to control the distribution of tobacco strip to more than two packing presses, it should be appreciated that the apparatus may be configured to control the distribution in any number, including all, of the packing presses and in any sequence, including sequentially or simultaneously. For example, in an apparatus configured to control the distribution of tobacco strip in three tobacco packing presses, the apparatus may be configured to control the distribution in two of the tobacco packing presses simultaneously while the third tobacco packing press is attended to remove a full container and insert an empty container. 
   It should be further appreciated that although the apparatus has been described as controlling the distribution of tobacco strip to tobacco packing presses, the apparatus may be used to control distribution of tobacco strip to other processing apparatus. It should be even further appreciated that the apparatus may be used to control the distribution of material other than tobacco strip. 
   It should be appreciated that although four ducts and nozzles are shown for each charger, any plural number of ducts and nozzles may be provided for each charger. It should also be appreciated that although a single duct  14  is shown as providing air flow from the housing  12 , any number of ducts may provide air flow from the housing. Each of the ducts may include a flow control device controllable by the PLC to control the air flow from the housing. It should be further appreciated that each nozzle may be connected directly to the housing by a duct. Although the flow control devices have been described as either blocking or permitting air flow, it should be appreciated that the flow control devices may be operable to control the air flow in a range between full air flow and complete blocking. The apparatus for controlling the distribution of tobacco strip according to the present invention may be installed into existing tobacco processing plants or factories, or it may be provided as part of a newly constructed tobacco processing plant or factory. 
   While the present invention has been disclosed with respect to the examples described above, it should be appreciated that numerous modifications may be apparent to those of ordinary skill in the art without departing from the spirit and scope of the present invention.