Abstract:
A mobile harvesting unit which utilizes a high volume fan to separate crops from foreign matter, has a dust suppression system which substantially reduces particulates which are discharged with the fan exhaust. The dust suppression system has two stages. The first stage separates larger particles of foreign matter by deploying an air stream cleaning chain upstream of the fan. The second stage is contained within a air stream discharge duct. Within the air stream discharge duct, a liquid, such as water, is sprayed into the dust entrained air stream. The moistened air stream flows through a plurality of collection members which extend radially from a brush drum, where the moistened dust particles are accumulated on the collection members, such that the volume of dust particles contained within the air discharged from the harvesting unit is substantially reduced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     U.S. Provisional Application No. 61/220,893 for this invention was filed on Jun. 26, 2009, U.S. Provisional Application No. 61,238,067 was filed on Aug. 28, 2009, and U.S. Provisional Application No. 61/278,522 was filed on Oct. 6, 2009, for which three applications these inventors claim domestic priority. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to agricultural equipment, and devices which are utilized with agricultural equipment for controlling dust and other particulates generated from operation of the equipment. In particular, a mobile harvester is disclosed which is used for harvesting crops, such as nuts and/or fruits, where the harvester utilizes high volume air generated by an on-board fan to separate crops from foreign matter. The disclosed harvester addresses problems presented by the deposition of particulate matter into the air through the air exhaust of the harvester. The disclosed harvester comprises means for reducing dust and other particulate matter generated by the operation of the machinery which, by the nature of its operation, would otherwise generate substantial quantities of dust and disperse it into the atmosphere. The general mechanisms employed by the disclosed harvester capture and immobilize dust particles before the particles are dispersed into the atmosphere by the fan exhaust emitted from the machinery. 
     Dust generation by agricultural and construction machinery is a known problem, particularly in arid areas. To name just a few problems caused by the dust generation, dust particles result in air pollution, water pollution, soil loss, human and animal health problems, and potentially hazardous reductions in visibility. In addition, the dust can adversely impact the health of various plants. In an effort to reduce dust production, some air pollution control districts impose various operating limitations on farm machinery or otherwise impose different dust control measures. 
     Dust generation from nut and fruit harvesting equipment can be particularly problematic. These devices typically utilize high volume fans to separate nuts and/or fruit from the debris which may be picked up by the harvesting equipment, including leaves, branches, dirt clods, soil, etc. (collectively, “foreign material”). However, a large portion of the foreign material is typically blown out through the fan discharge, resulting in the dispersion of a large volume of dust into the atmosphere. An example of such a harvester is disclosed in U.S. Pat. No. 4,364,222, which is incorporated herein by this reference. In these devices, a mixture of fruit or nuts (generally referred to as “crops”) and foreign material is picked up and deposited on conveyors enclosed by a housing connected to a fan inducing a vigorous flow of air through the conveyors. Various baffles, walls and guide plates direct the air so as to enhance the separation of the desirable crops from the foreign material. However, a substantial volume of foreign material is typically discharged into the atmosphere with a minimum amount of processing, thus creating a large discharge of dust. 
     SUMMARY OF THE INVENTION 
     The system described herein utilizes a primary separation methodology comprising an “air stream cleaning chain” to remove the larger particles of foreign material from the air stream before these particles are passed through the fan, pulverized, and discharged into the atmosphere. The collected larger particles of foreign material are thereafter deposited on a separate conveyor for discharge through an air lock and collected or disposed of as solid material rather than being entrained in the air stream and discharged through the fan exhaust. Not only does this greatly reduce dust produced by the discharge but it also greatly reduces fan wear by preventing the foreign material from passing through the discharge fan. The system further utilizes a fine particle collection methodology which is applied to the air stream which has passed through the air stream cleaning chain, which air stream contains fine particulate matter. 
     Harvested crops, such as fruit or nuts, and associated foreign material are gathered together at the front end of the harvesting unit by gathering means and then picked off the ground using lifting means such as a pick up belt or conveyor. The crops and foreign matter are eventually transferred onto a primary cleaning chain. As crops and foreign matter are transferred from the primary cleaning chain to an elevator chain, air is pulled through the cleaning chain and the articles conveyed thereon by the high volume fan. The air stream generated by the fan is effective in for removing the foreign material from the crops. It is to be appreciated that through the various stages of the device, a fraction of the crops and foreign material may be dropped from the harvester. Thus, the utilization of the terms “crops” and “foreign matter” are not intended to mean that the volume of these materials remain constant as they are transported through the stages of the invention. 
     The air stream cleaning chain is the key component of the primary separation methodology. The air stream cleaning chain may comprise, but is not limited to, a chain of about 4 feet in width which allows air to pass through the chain but stops larger foreign material such as grass, leaves, dirt clods, etc. Other embodiments of this component could include but are not limited to various widths, lengths, and structure of material that would accomplish the purpose of stopping foreign material while allowing the air to pass through. This allows the air stream cleaning chain to remove much of the foreign material from the air stream and delivering the foreign material to the cross conveyor discharge belt to be discharged from the machine through the air lock rather than being discharged through the fan. 
     Following this primary separation, the air discharge from the fan, which may include fine dust particles, is directed through an air baffle or air stream discharge duct, through which the air stream is discharged from the unit. The air stream discharge duct comprises dust particle suppression means comprising liquid introduction means and particulate collection means. 
     Liquid is introduced into the dust-laden air stream through liquid introduction means, such as spray tips, jets, or other orifices. For example, spray tips comprising a variety in number and tip size may be used for this purpose. As another embodiment, the system may utilize multiple manifolds of spray tips to offer various options of liquid volume to be introduced into the dust infused air stream. As another embodiment, the liquid introduction means may comprise nozzles contained within the walls of the air stream discharge duct. The liquid introduction means causes a pressurized liquid, such as water, to be sprayed into the dust-laden air stream, essentially creating a curtain of mist for the air stream to pass through. 
     The dust particle suppression system further comprises a dust scrubber, such as a wafer brush drum, through which the air stream passes after having passed through the spray of the liquid introduction means. The wafer brush drum consists of multiple wafer brushes mounted on a brush attachment sleeve. The wafer brush drum is typically rotated in a concurrent direction with the discharged air flow so as not to cause undue back pressure on the air system. The moistened air stream flows through the rotating wafer brush drum, which radially extending members collect small pieces of moist dirt from the air stream. The accumulated dust particles are discharged from the wafer brush drum as solids, thus allowing generally clean air to be discharged from the harvesting unit. 
     The disclosed dust suppression system may be adapted for use in any application which presents a high velocity air discharge to minimize the dust pollution from the discharge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a left hand view of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 2  is a right hand view of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 3  is a front view of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 4  is a rear view of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 5  is a top view of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 6  is an isometric view of the left hand side of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 7  is an isometric view of the right hand side of a harvester comprising an embodiment of the disclosed dust suppression system. 
         FIG. 8  is a sectional view of a harvester along line  8 - 8  of  FIG. 6 . 
         FIG. 9  is a sectional view of a harvester along line  9 - 9  of  FIG. 6 , with a portion of the housing removed to show the fan rotor and drum brush. 
         FIG. 10  is a top view of an embodiment of the harvester. 
         FIG. 11  is a sectional view taken along line  11 - 11  of  FIG. 10 . 
         FIG. 12  is a partial isometric showing a portion of the upper housing for for an embodiment of the disclosed dust suppression system. 
         FIG. 13  shows a partial front view of the housing for an embodiment of the harvester. 
         FIG. 14  is a sectional view taken along line  14 - 14  of  FIG. 13 . 
         FIG. 15  is a partial top view of the housing for an embodiment of the harvester. 
         FIG. 16  is a partial isometric view of the housing for an embodiment of the harvester. 
         FIG. 17  is a partial sectional view showing, among other things, the relative positions of the air stream cleaning chain and the cross conveyor discharge belt which may be utilized in an embodiment of the disclosed harvester. 
         FIG. 18  shows a partial isometric view of a fan-brush combination which may be utilized in an embodiment of the disclosed harvester, showing the flow direction. 
         FIG. 19  shows a partial side view of the fan-brush combination shown in 
         FIG. 18 . 
         FIG. 20  shows a partial top view of the exterior of the housing for the fan-brush combination shown in  FIG. 18 . 
         FIG. 21  shows a partial front view of the fan-brush combination shown in  FIG. 18 , showing an option for placement for liquid spray tips. 
         FIG. 22  shows a partial isometric view of a fan brush combination which may be utilized in an embodiment of the disclosed harvester. 
         FIG. 23  shows another view of a fan brush combination which may be utilized in an embodiment of the disclosed harvester. 
         FIG. 24  shows a view of a liquid introduction means which might be utilized in an embodiment of the disclosed harvester. 
         FIG. 25  shows a close up view of another liquid introduction means which might be utilized in an embodiment of the disclosed harvester. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Now with reference to the figures,  FIG. 1  shows an embodiment of a harvesting unit  10  which may comprise the dust suppression system disclosed herein. This type of harvesting unit  10  is mobile, having ground conveyance means such as wheels  12 , but it might also comprise tracks, rollers, etc. Harvesting unit  10  gathers harvested crops, such as nuts, fruits and the like, from the ground surface, where the crops will typically have been deposited from the shaking of trees or other harvesting method. The crops are typically deposited in a spread out configuration, forming a carpet on the ground surface. This type of harvesting unit  10  is well suited for the processing of almonds, but could also be utilized in the gathering of a variety of other crops lying on a ground surface after having been removed from a tree. In addition to almonds, the harvested crop may be another variety of nut, such as cashews, chestnuts, hazelnuts, macadamia nuts, pecans, walnuts and tung nuts. Certain fruits, such as figs and oranges, and any fruit, nut or vegetable, as conventionally known to require collection and processing from the ground, may also be gather with this type of harvester, and the present dust suppression system employed. It is to be appreciated that while the Figures herein show a harvester  10  which is equipped to be towed by a tractor or other towing vehicle, the present dust suppression system may equally be utilized with a self-propelled harvesting unit. The various conveyors, chains, drive wheels, etc. of the harvester will be driven by the means known in the art, typically by hydraulic motors. 
     The type of harvesting unit  10  which may comprise the dust suppression system disclosed herein generally comprises a collection means for collecting the agricultural products, such as crops  14 , from the ground surface S. Because the crops  14  are blanketed across the ground dispersed among other foreign matter  16 , such as leaves, twigs, dirt, gravel, dirt clods, etc., the collection means will gather a combination of all of these materials into the harvesting unit. The foreign matter  16  will typically comprise a mixture of larger and smaller particles, and some foreign matter will comprise dirt or other relatively fine grained particles. The collection means may comprise brushes, conveyors, or a sweeping array as disclosed in U.S. Pat. Nos. 7,131,254 and 7,412,817 which were invented by some of the inventors herein and which are incorporated herein in their entireties by this reference. One embodiment of the collection means may comprise a rotating sweeper  18  and/or pickup belt  20  which gather the agricultural products and foreign matter from the ground S. The collection means directs all of the gathered materials onto a primary chain  22 . The primary chain  22  has a receiving end  24  which receives the crops and foreign matter which have been collected by the collection means. At the end opposite the receiving end  24 , the primary chain comprises a delivery end  26  to which substantially all of the crops and foreign matter are delivered. However, it is to be appreciated that the primary chain  22 , and the other chains of most harvesters, are typically linked chain with openings, such that smaller foreign matter and perhaps smaller crops will fall through back onto the ground surface S. Therefore, while a substantial amount of the crops and foreign matter will reach the receiving end  24 , some of the crops and foreign matter may have fallen through the openings in the primary chain  22 . 
     The harvesting unit  10  further comprises an elevator chain  28 . The elevator chain  28  receives crops and foreign matter from primary chain  22 . The crops are carried up elevator chain  28  and discharged through discharge chute  30  to a storage container, the ground, or other repository for the crops. Adjacent to elevator chain  28  is the end  32  of a ductwork or housing  34  which may be oriented along the lengthwise axis of the harvesting unit  10 . An opening is defined at the end  32  of the housing by the top 36, side pieces  38 , and bottom  40 . A fan  42  is disposed within housing  34  within its own fan housing  46 . Fan  42  generates an air stream A by pulling air from the opening at the end  32  of the housing  34  and discharging the air into discharge duct  44  on the opposite site of the fan  42 . The air stream A flows through housing  34 , with the direction of the air stream generally moving from the elevator chain  28  toward the fan  42 . The fan  42  may thus be considered to have a suction side which is oriented toward end  32  and at least a portion of elevator chain  28  and a discharge side which begins on the opposite side of the fan, with the generated air stream discharging into air stream discharge duct  44 . As suction is pulled by the air stream A through the openings in elevator chain  28 , and through the crops and foreign matter being transported on the elevator chain, the lighter foreign matter is carried in the air stream toward fan  42  through housing  34 . 
     Disposed between fan  42  and elevator chain  28  is an air stream cleaning chain assembly  48 . The air stream cleaning chain assembly  48  comprises the primary separation methodology for removing foreign material from the air stream before much of the foreign material is passed through the fan  42  and discharged into the atmosphere. The air stream cleaning chain assembly  48  may comprise air stream cleaning chain  50 , drive roller  52  and idler rollers  54 . As air stream cleaning chain  50  is rotated about the idler rollers  54 , a portion of the air stream cleaning chain is continually positioned to be normal to the general direction of the air stream A. Air stream cleaning chain  50  allows the air stream to pass through it, but stops the larger particles of foreign material, such as leaves, grass, etc., because the air stream cleaning chain comprises a plurality of closely spaced links, wherein the openings between the links are relatively small. Air stream cleaning chain  50  may have a width of approximately four feet in width. 
     Foreign material which is stopped by the air stream cleaning chain  50  is discharged from the harvesting unit  10  by discharging means which transport the larger particles of the foreign matter collected on the air stream cleaning chain to the exterior of the harvesting unit. The discharging means may comprise a cross conveyor discharge belt  56  which is disposed below the air stream cleaning chain  50 . Foreign material accumulated on the air stream cleaning chain is deposited onto the cross conveyor discharge belt  56 , which transports the larger particles of the foreign material to a disposal duct through an air lock assembly  58 . 
     The finer particles of foreign material will be carried through the openings in air stream cleaning chain  50  and transported through housing  34  by air stream A through fan  42  and into air stream discharge duct  44 , which is on the discharge side of the fan. The air stream discharge duct  44  comprises a further mechanism for removing particulates from the air exhaust of the harvester  10 , which is utilized to remove smaller particles which passed through the air stream cleaning chain  50 . This mechanism employs injecting water or other appropriate liquid into the air stream A as it enters the air stream discharge duct  44 . As shown in  FIGS. 18 through 25 , the air stream discharge duct  44  comprises liquid introduction means such as a plurality of spray tips  60 , or other liquid introduction means, such as directional jets  160  shown on  FIG. 25 . Directional jets  160  may be set within the inside wall of air stream discharge duct  44  and may be installed and directed to provide a curtain of liquid spray through which the air stream A, with its entrained dust particles, passes. Other liquid introduction means may be utilized. For example, spray tips comprising a variety in number and tip size may be used for this purpose. As another embodiment, the system may utilize multiple manifolds of spray tips to offer various options for the introduction of the liquid into the dust infused air stream. The harvester  10  may comprise liquid storage tanks for storing the liquid utilized for the liquid sprayed into the air stream discharge duct  44 , and the related pumps and conduits required for the liquid injection process. Alternatively, the storage tanks and pumps may be carried on a separate apparatus. 
     The air stream discharge duct  44  may comprise additional means for suppressing the fine dust particles transported in the air stream A. The air stream discharge duct may further comprise a dust scrubber assembly  62 . Dust scrubber assembly  62  may comprise a rotating wafer brush drum  64 . The wafer brush drum consists of multiple wafer brushes  66  mounted on a brush attachment sleeve  68 , or other collection members which radially extend from the brush attachment sleeve. The wafer brush drum  64  may be rotated in a concurrent direction with the flow of air stream A so as not to cause undue back pressure on the air system. Because of the liquid introduction means discussed above, the air stream A reaching the wafer brush drum is moistened. As the moistened air stream A flows through the wafer brushes, small pieces of moist dirt are scrubbed from the air stream, accumulating on the collection members such that the air being discharged through air exhaust  70  has been substantially cleaned of particulate matter. Aggregated solids may be discharged from the apparatus through solids discharge chute  71 . 
     Air stream discharge duct  44  connects to fan housing  46  at flange  72 . Portions of air stream discharge duct  44  may be easily removable to gain access to the various components of the dust scrubber assembly  62  and the liquid introduction means contained therein. For example, flange  72  may be held together with a quick-release mechanism  74  and air stream discharge duct  44  may be hinge connected at the flange to allow the air stream discharge duct to pivot outwardly so there is easy access to the internal components. 
     While the above is a description of various embodiments of the present invention, further modifications may be employed without departing from the spirit and scope of the present invention. Thus the scope of the invention should not be limited according to these factors, but according to the following appended claims.