Patent Publication Number: US-2023132803-A1

Title: Mulch coloring

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to systems and methods for coloring mulch products, and, more particularly, to systems and methods that use a screw conveyor to transport mulch colorant from a tank to a mulch conveyor. 
     Mulch is a material with many applications, for example inhibiting weed growth, conserving soil moisture, and landscaping aesthetics. Mulch is often formed from an organic material, such as wood chips. For wood mulches in particular, while the natural color of the wood may be desirable for some applications, other colors may be desirable. 
     BRIEF SUMMARY OF THE INVENTION 
     A coloring system includes a reservoir that holds a colorant. A vibrator motor is attached to the reservoir and applies a vibration to the reservoir to cause the colorant to collect at a bottom of the reservoir. An auger moves the colorant from the reservoir to an outlet. 
     A mulch coloring system includes a reservoir that holds a powdered colorant. A vibrator motor is attached to the reservoir and applies a vibration to the reservoir to cause the colorant to collect at a bottom of the reservoir. A conveyor transports a coarse mulch material. An auger moves the powdered colorant from the reservoir to the conveyor. A grinder receives the coarse mulch material and the powdered colorant from the conveyor and grinds the coarse mulch material and the powdered colorant together to produce a colored mulch. 
     A method for coloring mulch includes dispensing powdered colorant from a reservoir, including vibrating the reservoir to cause the powdered colorant to collect at an outlet of the reservoir. Mulch material is transported to a grinder using a conveyor. Powdered colorant is added to the mulch material, on the conveyor, using an auger. The mulch material and the powdered colorant are ground together in the grinder to produce a colored mulch. 
     These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will provide details in the following description of preferred embodiments with reference to the following figures wherein: 
         FIG.  1    is a view of a coloring system that uses an augur to transport powdered colorant from a reservoir tank to a conveyor, in accordance with an embodiment of the present invention; 
         FIG.  2    is a view of an augur that can be used to transport powdered colorant from a reservoir tank to a conveyor, in accordance with an embodiment of the present invention; 
         FIG.  3    is a block/flow diagram of a method for using powdered colorant to color a mulch material, in accordance with an embodiment of the present invention; 
         FIG.  4    is a diagram of a process for coloring mulch, including inputs and outputs of a conveyor, in accordance with an embodiment of the present invention; 
         FIG.  5    is a block diagram of a motor that may be used to operate an augur, in accordance with an embodiment of the present invention; and 
         FIG.  6    is a block diagram of a vibrator motor that may be used to stop powdered colorant from clumping and sticking to walls of the reservoir tank. 
     
    
    
     DETAILED DESCRIPTION 
     Mulch material, such as wood chips, may be colored to any of a variety of colors before it is used, making it possible to use mulch as a decorative landscaping option. Any appropriate colorant may be used, such as a liquid or powdered colorant, but applying the colorant to the mulch can be challenging. Powdered colorant, in particular, may be difficult to apply evenly. However, powdered colorant can be used even when low temperatures would cause a liquid-based colorant to freeze. Additionally, wet wood can be difficult to use with liquid colorants, for example if the mulch material has been exposed to the rain, in which case a powdered colorant can be more effective. For similar reasons, powdered colorants are easier to store in cold conditions, because they do not freeze and so do not need to be kept warm. 
     A screw conveyor may be employed to efficiently move powdered colorant, from a tank or dispenser to a conveyor belt that transports mulch material. The screw conveyor may be used to apply the powdered colorant at a consistent rate to the passing material, ensuring the correct ratio of colorant to mulch. This can be performed as the mulch material passes to a grinder, where the material will be ground to an appropriate size and, at the same time, will be mixed with the powered colorant, thereby producing colored mulch with any desired granularity and color. 
     In some cases, the powdered colorant may clump or stick to the sides of the tank, rather than freely flowing down to the screw conveyor. Powdered materials are more likely to stick together than other materials, such as fluids or relatively large-sized grains (e.g., gravel or livestock feed), particularly in the presence of moisture or humidity. To address this, a vibrating motor may be attached to the tank. The vibrating motor causes clumped powdered colorant to detach from the side of the tank and fall down to the screw conveyor. 
     Additionally, due to the length of the screw conveyor, damage may occur when moving or operating the system, as the weight of the screw conveyor&#39;s motor, at the end of the length of the conveyor, causes a torque at the connection point between the screw conveyor and the tank. To address this, the tank may be made from a material with a relatively high durability. Thus, the tank may be formed from a metal, such as steel. 
     The drawings herein are shown for the sake of illustration, and should not be construed as limiting. For example, the sizes, relative proportions, and relative positioning of the illustrated elements is selected to convey concepts relating to embodiments of the present invention—these embodiments, and others, may be implemented within the scope of the present principles. 
     Referring now to  FIG.  1   , an exemplary colorant system  100  is shown. A tank  102  holds any appropriate quantity of powdered colorant. In one specific and non-limiting example, the tank  102  may hold 2000 lbs of powdered colorant and may have a volume of 75 cubic feet. Such a tank may have a height of 9′6″ and a diameter of 74″. In another specific and non-limiting example, the tank  102  may hold 3000 lbs of powdered colorant and may have a volume of 130 cubic feet. Such a tank may have a height of 11′5″ and a diameter of 74″. The tank  102  may have sloped walls that taper to a nozzle  104 , to funnel the powdered colorant inside the tank  102  to a feed point. The tank  102  may be mounted to a frame  116 , which has sufficient strength to hold the tank  102  at full capacity. The frame  116  may furthermore have a base that can accommodate a forklift, making it possible to move the tank  102  to any needed location. 
     The tank  102  may have a vibrator motor  103  attached. As will be described in greater detail below, the vibrator motor  103  may include any appropriate device that creates vibrations. The magnitude and/or frequency of the vibrations of the vibrator motor  103  may be set at a fixed size or may be controllable. It is specifically contemplated that the vibrator motor  103  may create oscillations in a direction that is parallel to the surface of the ground, to cause the walls of the tank  102  to vibrate, and thereby to cause clumped powdered colorant to disperse and fall to the bottom of the tank  102 , but it should be understood that any appropriate type of vibration may be used. 
     The vibrator motor  103  may be powered by any appropriate mechanism, including battery power, attachment to the electrical grid, an internal or external battery, or some form of local power generation, such as solar power or generator power. The vibrator motor  103  may be controlled by an on/off switch and by a settable vibration magnitude and/or frequency. The vibrator motor  103  may also be controlled remotely, for example via a radio control. 
     A screw conveyor may include an inlet  105 , a motor  106 , and an auger  108  in a housing. As powdered colorant  110  pours from the nozzle  104  and into the inlet  105 , the colorant meets the spiral blade of the auger  108 . The auger  108  is turned in place by the motor  106 . As the auger  108  turns within its housing, colorant  110  is moved along the length of the auger  108 . When the colorant  110  reaches the end of the auger  108 , it pours onto mulch material  112 . The mulch material  112  is carried on a conveyor  114 . The nozzle  104  may include a shutoff valve, to stop powdered colorant from pouring into the inlet  105 , for example while the auger  108  is being adjusted or serviced. 
     As noted above, the attachment point between the inlet  105  and the nozzle  104  may experience large torques, particularly when the system is operated or relocated. To prevent damage to the tank  102  and the nozzle  104  during high-torque events, the tank  102  may be formed from a durable material, such as steel, and the nozzle  104  in particular may be reinforced to better handle the torque. 
     The mulch material  112  may include any appropriate material, at any degree of granularity. For example, the mulch material  112  may include waste wood from construction, fallen branches, trees, or any other appropriate organic or inorganic material. The mulch material  112  may include large pieces, representing material of a coarse granularity, or may include relatively small pieces, representing material of a fine granularity. 
     The colorant may be any appropriate powdered colorant, such as carbon black and iron oxide materials. Due to the density of the powdered colorant  110 , it may be preferable to use an auger  108  with a solid central core, rather than a hollow core. Additionally, the motor  106  may need to have a relatively high power output. In one specific and non-limiting example, the auger  108  may have a 4″ diameter and a length of 11′, and may use a synchronous belt drive motor  106  having a power of 2 hp and a 4× variable frequency rive. The motor  106  may have an adjustable speed, which controls a rate at which the powdered colorant  110  is moved from the tank  102  to the mulch material  112 . In one specific and non-limiting example, the auger  108  may move between 6 and 60 lbs of powdered colorant  110  per minute. 
     A water supply may also be introduced, with a hose  118  that transports water  120  to the conveyor  114 . The hose  118  may include any appropriate nozzle to evenly apply water to the passing mulch material. Water  120  may be transported separately from the powdered colorant  110  to prevent the powdered colorant  110  from clumping and clogging the auger  108 . The water supply may include a control value (not shown), which may include a globe valve that can be operated by hand. The hose  118  may be routed through a water flow gauge before continuing to a dispensing nozzle. The dispensing nozzle may be positioned to add water to the mulch material  112  before or after the powdered colorant  110  is added, and may provide a variety of dispensing patterns to control wetting and dust control for different sizes of the conveyor  114 . 
     As noted above, the speed of the motor  106  and the conveyor  114  may be controlled to control the speed at which mulch material  112  moves past the auger  108 , as well as the speed at which powdered colorant  110  is dispensed from the auger  108 . The speed of each may be selected to apply specific amount of powdered colorant  110  per volume or weight of mulch material  112 , thereby setting the correct ratio of each for a particular colorant and a particular mulch material  112 . The motor  106  may furthermore include a remote control, for example using a radio transceiver or corded control interface. In this manner, the motor  106  can be remotely turned on and off, for example while an operator controls the speed of the conveyor  114 . In this way, the operator can conveniently operate the entire system  100  form a single location. 
     The angle between the auger  108  and the ground may be adjustable, for example by a hinge at the inlet  105 . The auger  108  may thereby be set to any appropriate height for the conveyor  114  that is being used. For a conveyor  114  that lifts the mulch material  112  to the inlet of a grinder, the height of the auger  108  may be set to any appropriate height along the length of the conveyor  114 . The adjustment of the angle may be made automatic with the inclusion of a second motor (not shown). 
     Referring now to  FIG.  2   , additional detail is provided on the auger  108  and the motor  106 . The auger  108  includes a housing  202  that has a top opening  204  to allow powdered colorant to enter, and a bottom opening  210  to allow the powdered colorant to fall out, after it has traveled the length of the auger  108 . The auger  108  operates by the rotation of a screw, which includes a shaft  206  and a blade  208 , where the blade  208  spirals around the shaft  206 . As noted above, it is specifically contemplated that the high density of powdered colorant may call for a shaft  206  that has a solid core, rather than a hollow core, to prevent flexing, but it should be understood that hollow-core shafts are also contemplated. 
     The motor  106  operates the screw, for example, by a belt  212  that rotates one end of the shaft  206 . As the shaft  206  turns within the housing  202 , the blade  208  rotates and moves the powdered colorant through the length of the housing  202 , until it reaches the bottom opening  210 . The motor  106  may operate at any appropriate speed. Additionally, the belt  212  may be exchanged for a belt of a different length, along with changing the diameter of the rotor of the motor  106 , to change the amount of torque and speed that are applied to the shaft  206 . In this manner, the rate at which powdered colorant may be expelled from the bottom opening  210  can be adjusted. 
     Referring now to  FIG.  3   , a method for coloring mulch is shown. At block  302 , the end of the auger  108  is positioned over a conveyor  114  that will transport mulch material  112 . In particular, the bottom opening  210  may be positioned over the conveyor  114 . At block  304 , powdered colorant  110  may be added to the tank  102 . While colorant  110  may be added to the tank  102  before positioning the auger  108 , the weight of the full tank may make it difficult to position the auger  108 . 
     Block  306  deposits mulch material  112  onto the conveyor  114  at a first rate, where the conveyor  114  may be in motion, transporting the mulch material  112  from a source to a grinder. The first rate may be selected in accordance with a rate at which the mulch material  112  can be supplied and a rate at which the mulch material  112  can be processed in the grinder. 
     Block  308  sets the auger  108  to deposit powdered colorant  110  onto the moving conveyor  114  at a second rate, for example by setting a speed of the motor  106 . The second rate may be selected according to the first rate and to a predetermined ratio of colorant to mulch material to ensure that the correct amount of colorant is consistently and evenly added. During operation of the auger  108 , block  308  may vibrate the tank  102  to cause colorant  110  to fall from the walls of the tank  102  and to accumulate at the nozzle  104 . This prevents powdered colorant  110  from sticking to interior sidewalls of the tank  102 , so that the powdered colorant  110  can be used in its entirety. The vibration may be applied continuously, periodically, or intermittently. In a periodic application, the vibrations are applied at regular intervals, while in intermittent application, the vibrations are applied at irregular intervals or upon command. 
     Block  310  adds water  120  to the mulch material  112  at a third rate. The third rate may be selected according to the first rate and to a predetermined ratio of water to mulch material  112 , to ensure that the mulch material has the correct degree of moisture. Table 1 describes some exemplary rates for the mulch material  112 , colorant  110 , and water  120 . 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Wood (yards per hour) 
                 Dry colorant (lbs per hour) 
                 Water (gallons per hour) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 100 
                 300 
                 100-500  
               
               
                 200 
                 600 
                 200-1000 
               
               
                 300 
                 900 
                 300-1500 
               
               
                 400 
                 1200 
                 400-2000 
               
               
                 600 
                 1800 
                 600-3000 
               
               
                   
               
            
           
         
       
     
     Block  312  grinds the mulch material  112 , together with the powdered colorant  110  and the water  120 , to produce a colored mulch product. The grinder may be set to produce a mulch output that has any appropriate granularity, and may keep material within it for any appropriate amount of time to ensure that the colorant  110  is evenly mixed with the mulch. 
     Referring now to  FIG.  4   , a side view of the system  100  is shown, with a focus on the progression of the mulch material  112 . The mulch material  112  is deposited on the conveyor  114  from mulch source  402 , and may include any appropriate organic or inorganic mulch material, with pieces at any appropriate size. As the top surface of the conveyor  114  moves from left to right within the perspective of  FIG.  4   , color is added at point  404 , for example by the auger  108 , described above. Optionally, water  120  may also be added at point  406 . 
     Notably, the order of these steps may be altered, as appropriate. For example, the addition of color at point  404  and the addition of water at point  406  may be reversed. Other materials may be added as well. For example, mulch material  112  may be added at multiple mulch points  402 . Similarly, multiple colorants  110  may be added at different color points  404 . Any other appropriate additives may be included as well, whether added at a separate point, or mixed with one of the illustrated points. 
     At the end of the conveyor  114 , the combination of mulch material  112  and additives is deposited into a grinder  408 . The grinder  408  grinds the mulch material  112  to a predetermined granularity, evenly mixed with water  120  and powdered colorant  110 , as well as any other additives. The grinder  408  outputs the colored mulch, for example into a hopper or a separate conveyor, to be stored or used. 
     Referring now to  FIG.  5   , additional detail on the motor  106  is shown. While it is specifically contemplated that the motor  106  may be an electric motor, it should be understood that the role of the motor  106  may be performed by any appropriate source of power, including, for example, an internal combustion engine, a windmill, or a waterwheel. The motor  106  turns a rotor  510 , which turns the shaft  206  of the rotor  108  using a belt  212 , as described above. 
     The motor  106  may include several functional components. A power source  502  provides, e.g., electrical power. The power source  502  may include any source of electrical power, such as a connection to the electrical grid, a battery, a gas-powered generator, or solar or wind power. The power source  502  is used to power the stator  508  and rotor  510 , causing the rotor  510  to turn. 
     The operation of the motor  106  can be controlled, for example using speed control  504  and remote control  506 . The speed control  504  determines a speed of rotation for the rotor  510 , and thus controls the speed at which powdered colorant  110  is added. The remote control  506  may include a wired or wireless control, for example including a radio transceiver, that receives instructions. Such instructions may include, for example, instructions to set the speed via the speed control  504  and instructions to cut off power via the power source  502 . The remote control  506  thereby provides an operator with the ability to turn the motor  106  on and off from a remote location. 
     The remote control  506  may include a radio receiver that operates at UHF frequencies, for example between about 300 MHZ and about 3 GHz. The remote control  506  may further include a selector switch that may control the mode of operation of the motor  106  (e.g., off, forward, backward) and the speed of the motor  106 . The instructions may be encoded in a radio transmission according to any appropriate encoding scheme. 
     Referring now to  FIG.  6   , a block diagram of a vibrator motor  103  is shown. The depicted vibrator motor  103  is shown as an eccentric rotating mass vibration motor, but it should be understood that other types of vibrator motor, such as a linear resonant actuator, may be used instead. 
     The vibrator motor  103  includes an electric motor  602 , which is powered by power source  604 . As noted above, the power source  604  may be any appropriate source of electrical power, including an internal power source, such as a battery, or an interface to an external power source, such as connection to an electrical grid, a renewable source like a solar cell, or a electrical generator. The controller  606  controls the operation of the electric motor  602 , including whether the electric motor  602  is turned on and the speed of its operation. 
     In an eccentric rotating mass vibration motor  103 , the electric motor  602  spins an unbalanced mass  608 . As the unbalanced mass  608  rotates around a rotor axis of the electric motor  602 , its momentum causes a vibration in the vibrator motor. By securely attaching the vibrator motor  103  to a wall of the tank  102 , these vibrations are transferred to the tank  102 , where they cause clumped powdered colorant to fall from the wall and collect at the bottom of the tank  102 . 
     The vibrations generated by the unbalanced mass  608  may be controlled via the controller  606 , as the speed of the rotation of the electric motor  602  will correspond to the speed and magnitude of the unbalanced mass oscillations, which similarly correspond to the speed and magnitude of the resulting vibrations. 
     The vibrator motor  103  need not be operated continuously. In some cases, the vibrator motor  103  may be operated periodically, or on command, to dislodge accumulated powdered colorant from the walls of the tank  102 . Such periodic or intermittent operation may conserve electrical power by turning off the electric motor  602  between periods of operation. 
     The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention.