Abstract:
A coloring agent addition system which generally includes a processing module having an in-feed conveyor for receiving and processing a raw material and a coloring unit connected to the in-feed conveyor for adding a coloring agent to the raw material. The coloring unit is driven by the processing module to deliver the coloring agent depending on operation of the processing module. The coloring unit includes a motor that is in fluid communication with a hydraulic fluid line of a processing module motor, whereby the processing module motor is connected in series to the coloring unit motor to drive the coloring unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/475,146, filed on Jun. 2, 2003. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to coloring agent addition systems and, more particularly, to a system for adding a dry coloring agent to a landscape product processing stream. The present invention has broader application to all such machinery that reduce particle size or classify particle size of incoming materials and addresses the need for environmentally sound and low-cost coloring of materials to meet market demands.  
         BACKGROUND OF THE INVENTION  
         [0003]    Landscape product manufacturers, and other related industries, use horizontal bulk material grinders, shredders, and screening devices (“the processing equipment”) to produce large volumes of material such as garden mulch and compost. Such processing equipment provide particle size reduction and particle size classification. For certain types of landscape products, a coloring agent is added to enhance the product&#39;s appearance and aesthetic value.  
           [0004]    The most common approach for adding color to these materials is by spraying a liquid coloring agent on the material, either at the raw material inlet or at the raw material outlet of the processing equipment. Because the material passes below on a conveyor belt, application of a liquid coloring agent at the processing equipment outlet results in an over application of color to the material on top of the belt and an under application of color to the material underneath. Other drawbacks of liquid coloring agents are their relatively high costs in comparison to dry coloring agents and the fact that liquid coloring agents cannot be used in freezing winter climates and require water flows up to 20 gallons per minute for diluting concentrated liquid coloring agent and spraying onto the raw material.  
           [0005]    Dry coloring agents are available on the market, however, primitive practices are currently required to mix it with raw material. These practices include dumping sacks of dry coloring agent on large piles of raw material and re-mixing the entire pile to distribute the coloring agent, or filling a bulldozer bucket with dry coloring agent and dumping it on the pile, followed by more mixing. In either case, these practices result in significant amounts of fugitive dust, health hazards to employees, and increased costs from additional material handling. Further, these practices do not achieve an acceptable consistency of coloring necessary for maximum market value of the finished product.  
           [0006]    Application of either a liquid or a dry coloring agent at the processing equipment inlet would allow better mixing of the coloring agent and the raw material with a minimum of additional material handling. However, it is difficult to achieve consistent coloring when waste material flow rates fluctuate during normal processing, due to plugs, excessive moisture, and other normal variations in material consistency.  
           [0007]    Accordingly, it would be desirable to provide a low-cost coloring unit for installation on any horizontal processing equipment inlet conveyor that can efficiently and automatically respond to changes in raw material feed rates while taking advantage of the processing equipment&#39;s natural mixing operation to apply the coloring agent concurrently and proportionally.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is a coloring agent addition system generally including a processing module having an in-feed conveyor for receiving and processing a raw material and a coloring unit connected to the in-feed conveyor for adding a coloring agent to the raw material. The coloring unit is driven by the processing module to deliver the coloring agent depending on operation of the processing module. Preferably, the coloring agent is delivered at a rate dependent on a rate of operation of the processing module.  
           [0009]    In a preferred embodiment, the processing module includes a hydraulic motor for driving the in-feed conveyor and the coloring unit includes a hydraulic motor for delivering the coloring agent to the raw material. The coloring unit motor is in fluid communication with a hydraulic fluid line of the processing module motor, whereby the processing module motor is connected in series to the coloring unit motor to drive the coloring unit.  
           [0010]    Preferably, the coloring unit includes a hopper for containing an amount of coloring agent, a motor and a rotating metering shaft. The hopper has a bottom with an opening and the rotating metering shaft is disposed adjacent the hopper bottom opening. The metering shaft is driven by the motor to deliver the coloring agent through the hopper bottom opening. The rotating metering shaft may include at least one groove for receiving and intermittently delivering a fixed amount of coloring agent through the hopper bottom opening as the metering shaft rotates.  
           [0011]    The hopper may further include an inclined side wall and a removable wear plate made from a low-friction material disposed on an interior of the side wall. Also, the coloring unit may further include a rotating agitator driven by the motor for tumbling the color agent within the hopper.  
           [0012]    The present invention further involves a method for adding a coloring agent to a raw material stream. The method generally includes the steps of receiving the raw material on an in-feed conveyor of a processing module, delivering the coloring agent to the raw material upstream of the processing module at a rate dependent on a rate of operation of the processing module and mixing the raw material and the coloring agent in the processing module.  
           [0013]    In a preferred embodiment, the rate of operation of the processing module is communicated to a coloring unit, which delivers the coloring agent to the raw material. Preferably, hydraulic fluid is routed from a processing module motor to a coloring unit motor, wherein the rate of operation of the coloring unit motor is dependent on the rate of operation of the processing module motor. The processing module motor drives the in-feed conveyor of the processing module and the coloring unit motor drives the delivery of the coloring agent to the raw material.  
           [0014]    The present invention may take the form of a coloring unit that can be mounted on any conventional horizontal processing equipment inlet conveyor. The unit is interconnected with the existing processing equipment hydraulic system and interlocked to deliver the proper amount of coloring agent in proportion to the processing equipment raw material in-feed rate, thus assuring consistent, high-quality, low-cost colored material for market. By interconnecting in series with the existing hydraulic system, the dry coloring unit stops whenever the processing equipment stops, thus minimizing spillage and excessive loss of coloring agent typical for prior art inlet coloring systems.  
           [0015]    The present invention utilizes a hopper, specially designed to deliver coloring agent without bridging or plugging, an agitator to deliver coloring agent to a metering shaft, and a low-cost aluminum extruded grooved metering shaft to meter coloring agent onto the waste in-feed conveyor. By stopping and starting the dry coloring unit&#39;s hydraulic drive motor in response to the main processing equipment operation, exact control is achieved with a minimum amount of waste or spillage.  
           [0016]    The present invention is inexpensive to construct and operate because of its parasitic use of the existing hydraulic system of the processing equipment (e.g., grinder or shredder) and solves all of the problems associated with the current practices. Even transportation cost of finished product to market is minimized by completely eliminating the use of water in liquid coloring systems.  
           [0017]    The preferred embodiments of the coloring agent addition system as well as other objects, features and advantages of this invention, will be apparent from the following detailed description, which is to be read in conjunction with the accompanying drawing.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0018]    [0018]FIG. 1 is a schematic drawing of the coloring agent addition system formed in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    The present invention improves upon the current art of applying liquid and dry coloring agents to large volumes of raw landscape material to enhance the marketability of processed landscape products such as landscape mulch and other products. Such landscape raw material may include lawn clippings, tree branches and other yard wastes. It has become increasingly more common for residential communities to have separate municipal yard waste collection for delivery to recycling facilities, which in turn convert the yard waste to valuable landscape products. During processing, however, it is often desirable to provide an aesthetically pleasing color to the landscape product. The present invention provides a simple yet innovative method for metering and controlling dry coloring agents onto the in-feed conveyor of a recycling facility&#39;s raw material processing equipment. Existing technology offers either liquid systems, that are more expensive and more difficult to control, or primitive dry application procedures that are inefficient, dangerous, and unhealthy.  
         [0020]    [0020]FIG. 1 is a schematic diagram showing the design features of the coloring agent addition system  10  of the present invention. The system  10  generally includes a dry coloring unit  12  mounted on the side rails  14  of an in-feed conveyor  16  of a processing unit  18 . As discussed above, the processing unit  18  includes processing equipment, such as a horizontal grinder, shredder, mixer or screening device, for mixing and/or reducing the particle size of the incoming raw material  19 . The processing unit  18  further includes a motor  20  for simultaneously driving both the processing equipment and the in-feed conveyor  16 . For example, the in-feed conveyor  16  may be driven by the processing unit motor  20  via a sprocket  21  and a belt or chain  22 .  
         [0021]    The system  10  shown in FIG. 1 and described herein below is a hydraulic system, wherein the processing unit motor  20  is a hydraulic motor connected to a hydraulic fluid supply line  24  and a hydraulic fluid return line  26 . However, it is conceivable that the system of the present invention can be electrically driven. In such case, the hydraulic fluid supply line  24  and the hydraulic fluid return line  26  would not be needed.  
         [0022]    The coloring unit  12  may be mounted to the side walls  14  of the conveyor  16  using four to six adjustable mounting feet  28 . Preferably, a breaker bar  30  is provided to stiffen the mounting structure of the unit  12  and protect the unit from damage by passing raw material. The dry coloring unit  12  includes a dry coloring unit hopper  32 , which is constructed preferably of ¼″ steel plate and is designed to hold up to 1,000 pounds of a dry coloring agent  33 , normally available in standard packages. The hopper  32  includes a bottom  34  having an opening  35  through which the dry coloring agent  33  is gravity-fed and applied to the incoming raw material  19 . An inclined side  36  of the main hopper  32  is preferably provided with a removable wear plate  38  made of a suitable low-friction material, such as polyethylene plastic, to facilitate the downward flow of the coloring agent  33 . The wear plate  36  can be secured to the inclined side  36  of the hopper  32  by mounting bolts that are countersunk to provide a smooth sliding surface for the coloring agent inside the main hopper.  
         [0023]    The dry coloring unit  12  is further provided with a motor  40 , which drives a sprocket  41  and chain  42 . The hopper chain  42  drives an agitator  44 , which may include blades or fins  46 , for tumbling the dry coloring material within the main hopper  32 . This tumbling action eliminates bridging of the dry coloring agent and regulates feed to a coloring agent metering shaft  48  located adjacent the opening  35  of the hopper bottom  35  and which is also driven by the hopper chain  42 . The coloring agent metering shaft  48  is a specially designed low-cost aluminum extruded grooved shaft, which is adapted especially for consistent delivery of dry coloring agent. The grooves  50  of the shaft  48  hold a fixed amount of dry coloring agent to be delivered through the opening  35  of the hopper bottom  34 . The delivery rate of the coloring agent metering shaft  48  can be varied by varying the speed of the motor  40 .  
         [0024]    As mentioned above, in a preferred embodiment, the system  10  of the present invention is hydraulically driven. Accordingly, the hopper motor  40  is a hydraulic motor having a hydraulic fluid inlet  52  and a hydraulic fluid return  53 . The hydraulic fluid inlet  52  and the hydraulic fluid return  53  of the hopper motor  40  are fluidly connected to the existing hydraulic system of the processing unit  18 . For example, hydraulic fluid from the return line of the processing unit&#39;s hydraulic motor  20  can be rerouted first through a check valve  54 , to protect against reverse operation of the processing equipment, and further through a control valve  55  to the hopper hydraulic motor  40 .  
         [0025]    Preferably, the rate of operation of the processing module motor  20  determines the rate of operation of the hopper motor  40 . However, the control valve  55  can be manually adjustable to provide varying speeds to the hydraulic hopper motor  40  for different types of coloring needs and products. Hydraulic fluid not passing through the control valve  55  is bypassed, along with fluid leaving the hydraulic hopper motor  40  to the main processing equipment hydraulic fluid return line  26 .  
         [0026]    In operation, as the hydraulic motor system  20  of the raw material processing unit  18  is activated to feed raw material  19  along the in-feed conveyor  16 , hydraulic fluid from the processing equipment is supplied to the hydraulic hopper motor  40  to activate the coloring agent addition unit  12 . The hopper chain  42  connected to the motor  40  in turn drives the agitator  44  and the coloring agent metering shaft  48  to intermittently deposit a fixed amount of dry coloring agent  33  through the bottom opening  35  of the hopper  32  onto the raw material passing below the hopper on the in-feed conveyor  16 . The combined raw material  19  and coloring agent  33  is then fed to the processing equipment of the processing unit  18  where it is mixed thoroughly to provide a uniformly colored finished landscape product. If for any reason the raw material in-feed conveyor  16  is stopped by the processing unit motor  20 , the hydraulic hopper motor  40  is also automatically stopped since its hydraulic fluid supply is tied to the hydraulic line of the processing unit. This prevents the coloring agent addition system of the present invention from continuing to operate if there is a stoppage of raw material flow.  
         [0027]    By connecting the hopper motor  40  in series with the processing equipment motor  20 , the hopper motor operates only when the processing equipment motor operates. This arrangement provides positive shut-off in the event of processing equipment stoppage. Moreover, in the preferred embodiment, the feed rate of the dry coloring agent  33  through the hopper  32  varies proportionally with the speed of the raw material in-feed rate, both of which is determined by the processing equipment motor  20 . Thus, the present invention improves upon problems with current art related to feeding too much or too little coloring agent when surges or plugs of raw material occur, as they do frequently in normal operation.  
         [0028]    Although the preferred embodiments of the present invention have been described with reference to the accompanying drawing, it is to be understood that the invention is not limited to those precise embodiments, and that other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the invention.