We disclose an apparatus for measuring by volume and delivering fluent solid materials comprising a screw conveyor and a knife assembly. Specifically, we disclose a horizontally oriented apparatus for the even dispensing of a metered quantity of powder.
Existing fluent material dispensers are subject to the material clogging and clumping at the discharge end. Attempts to resolve this problem have been attempted previously, as disclosed, for example, by Hirsch U.S. Pat. No. 7,487,892 and U.S. Pat. No. 8,556,129. However, the addition of a dispersal screen creates an additional location for clogging and clumping of fluent material.
We disclose an apparatus for the even dispensing of a metered quantity of powder. A hopper holds the powder. The hopper has a mixing portion having a first beater and a second beater. A conduit is coupled to the hopper and receives powder from the hopper. The conduit extends horizontally from the hopper. A screw conveyor—or auger—within the conduit transfers the material through the horizontal conduit. The horizontal conduit has a distal end, away from the hopper, that has a discharge end for dispensing the material. As the screw conveyor turns, the material is transferred through the conduit and toward the discharge end. A knife assembly, disposed at the distal longitudinal end of the screw conveyor, breaks off a continuous and even flow of powdered material out the discharge opening.
In order to provide an even flow of material to the knife assembly, the apparatus may have a spacing element disposed within the conduit between the distal longitudinal end of the screw conveyor and the knife assembly. The spacing element may facilitate the even compaction of the fluent material to be dispensed.
The knife assembly may have multiple vanes radially extending from a central collar. Each vane can have one or more beveled edges to facilitate shaving the compacted material into a constant stream. Each vane has a leading edge and a trailing edge. In one embodiment, the leading edge is beveled. However, it is also possible that the knife assembly employs vanes comprising round bars, for example the knife assembly can comprise multiple round bars radially extending from a central collar like the hands of a clock. It is also possible that the knife assembly is knife has a single vane.
The knife assembly and screw conveyor must be powered. In one embodiment, a motor is operationally coupled to turn both the screw conveyor and the knife assembly. The spacing element can either be rotated or stationary. For example, the motor is operationally coupled to a rotating, keyed shaft. The screw conveyor has a complementary longitudinal slot for receiving the keyed shaft and rotating with the keyed shaft. Similarly, the knife assembly has a slot for receiving and rotating with the keyed shaft. The spacing element may have a keyed slot for receiving and rotating with the keyed shaft.
Another advantage of this technology is that the dispensing rate range of the horizontal fluent material dispenser can be adjusted by varying the root diameter of the screw conveyor. The screw conveyor can consist of a narrow root shaft with elongated spiral blades. Alternatively, the screw conveyor can consist of a wide root shaft with narrow spiral blades. The wide shaft embodiment may provide the advantage of decreasing the flow rate of material compared with a narrow shaft screw conveyor through conduits of similar diameter. In order to achieve similar flow rates with the wider shaft, the motor needs to turn the screw auger at a higher number of rotations per minute. By powering the knife assembly on the same rotating shaft as the auger, the number of rotations per minute of the knife assembly also increased.
Another advantage of this technology is that multiple modular screw conveyor portions can be utilized to control the material flow. For example, a first screw conveyor flight module can be installed under the hopper portion to load the conduit with powdered material. A second screw conveyor flight module can be coupled to the first screw conveyor flight module. This second screw conveyor flight module can have the same root-blade profile as the first screw conveyor flight module or can have a different root-blade profile. The selection of the proper root-blade profile will depend on the material to be dispensed and the specific application. For example, in seed treatment implementations, the amount of dry agrochemical material dispensed may vary depending on the type of agrochemical and the seed treatment rate.
The root-blade profile can be altered to provide flow volume and flow rate. For example, the screw conveyor can comprise a plurality of spiral blades which provides a more rapid rate of horizontal travel per rotation than a single spiral blade.
Another advantage is that the conduit provides a hood of the discharge aperture, to prevent material from flowing into the conduit. In seed treatment implementations, the fluent material dispenser may dispense dry agrochemical additives such as talc or graphite. The treated seed is wet and sticky. The hood prevents the wet, sticky seed from entering the conduit and blocking the flow of the powdered agrochemicals.
A control system can be coupled with the motor to adjust the dispensing rate. The control system regulates the speed of the screw conveyor. For example, a motor may be directly connected to a first beater, with a sprocket gear for receiving a chain for driving both a second beater and the screw conveyor. By regulating the speed of the motor, the speed of the beaters and the speed of the screw conveyor are affected. In another embodiment, a separate motor is coupled to the screw conveyor to independently control the speed of the screw conveyor relative to the speed of the first beater and the second beater.
Aspects are illustrated by way of example, and not by way of limitation, in the accompanying drawings, wherein:
As noted above, this horizontal fluent material dispenser overcomes numerous problems, such as:
We disclose an apparatus for the even dispensing of a metered quantity of powder over a large range of dispensing rates. A hopper 10 holds the powder. The hopper 10 has an upper portion 112, a lower portion 114, and a mixing portion 11. The mixing portion 11 has a first beater 17 and a second beater 18. A conduit 20 is coupled to the hopper 10 and receives powder from the hopper 10 by flow of gravity. The conduit 20 extends horizontally from the lower portion 114 of the hopper 10.
A screw conveyor 50 within the conduit 20 transfers the material horizontally through the conduit. Several embodiments of the screw conveyor 50 having different root-blade profiles are illustrated in
Once transferred horizontally through the length of the conduit 20, the material is discharged through a discharge aperture 35. The discharge aperture 35 is disposed at a distal end 25 of the conduit 20, away from the hopper 10. As the screw conveyor 50 turns, the material is transferred through the conduit 20 and toward the discharge point at the distal end 25.
The material is continuously broken off into a fine, even flow with a knife assembly 85. The knife assembly 85 is disposed at the distal longitudinal end of the screw conveyor, breaks off a continuous and even flow of powdered material out the discharge opening. The knife assembly 85 is disposed adjacent to and above the discharge aperture 35, as shown in
The knife assembly 85 may have multiple vanes radially extending from a central ring shaft. Each vane can have one or more beveled edges to facilitate shaving the compacted material into a constant stream. Each vane has a leading edge and a trailing edge. As illustrated in
In embodiments having a powered shaft or a keyed shaft extending from the upstream screw conveyor portion, the knife assembly 85 may be secured to the shaft by a fastener (not shown) received through a fastener receiver 95 in the ring shaft 87. The fastener extends through the fastener receiver 95 to engage the shaft. The knife assembly 85 may also receive the rotational power through a keyed slot 105, as shown in
In order to provide an even flow of material to the knife assembly 85, the apparatus may have a spacing element 100 disposed within the conduit 20 between the distal longitudinal end of the screw conveyor and the knife assembly 85. The spacing element 100 is shown most clearly in
The knife assembly 85 may be a unitary assembly with a screw conveyor portion, as shown in
To deliver the fluent material, such as a powdered agrochemical, a horizontal conduit extends from the lower portion of the hopper. The conduit can also be referred to as a stinger in the context of a seed treatment system application, as the conduit is inserted into the mixing-drying drum through either the inlet opening or the discharge opening. The mixing-drying drum is not disclosed in detail in this application, but would be similar to the mixing-drying drum disclosed in U.S. patent application Ser. No. 14/301,404 by Terry N. Kaeb et al., the disclosure of the mixing-drying drums and the inlet opening and discharge opening is incorporated herein by reference.
In order to protect the wet, sticky, freshly treated seed from entering into the conduit 10, the conduit has a hood portion 37 that extends over the discharge aperture. As illustrated in
The knife assembly 85 and screw conveyor 50 must be powered to transfer the material through the conduit 20 and to allow the knife assembly 85 to break off the material. In one embodiment, a mixing motor 15 is operationally coupled to turn the first beater 17 and the screw conveyor 50. The rotating knife is rotationally coupled to the screw conveyor 50, and receives the rotational power through the screw conveyor. The spacing element can either be rotated or stationary. For example, the motor is operationally coupled to a rotating, keyed shaft. The screw conveyor has a complementary longitudinal slot for receiving the keyed shaft and rotating with the keyed shaft. Similarly, the knife assembly 85 has a slot for receiving and rotating with the keyed shaft 65. The spacing element may have a keyed slot for receiving and rotating with the keyed shaft 65.
Another advantage of this technology is that the dispensing rate range of the horizontal fluent material dispenser can be adjusted by varying the root diameter of the screw conveyor. The screw conveyor can consist of a narrow root shaft with elongated spiral blades. Alternatively, the screw conveyor can consist of a wide root shaft with narrow spiral blades. The wide shaft embodiment may provide the advantage of decreasing the flow rate of material compared with a narrow shaft screw conveyor through conduits of similar diameter. In order to achieve similar flow rates with the wider shaft, the motor needs to turn the screw auger at a higher number of rotations per minute. By powering the knife assembly 85 on the same rotating shaft as the auger, the number of rotations per minute of the knife assembly 85 also increased.
In order to properly dispense the material at a predetermined rate, a scale 125 may be provided that receives the hopper 10 and the hopper 10′s contents to generate a mass signal. As shown in
The horizontal fluent material dispenser can be used with a seed treatment application system. The conduit 20 is configured to extend into a mixing-drying drum. In this application, the control system 125 is configured to receive a seed flow rate signal from the seed treatment system. A scale-based seed applicator can generate a mass-based loss-in-weight seed flow rate signal. Alternatively, a seed wheel can generate a volumetric seed flow rate signal. These methods of generating a seed flow rate signal are known in the art. The control system 125 is further configured to change the screw conveyor speed signal in accordance with a recipe based on the seed flow rate in order to dispense a quantity of dry, powdered agrochemical corresponding to the quantity of seed in the mixing-drying drum.
Certain applications of the horizontal fluent material dispenser may require a low dispensing rate and other application require a much higher dispensing rate. It is possible to adjust the range of dispensing rates through a standard diameter conduit by adjusting the blade-root profile of the screw conveyor 50 or a portion of the screw conveyor. A first screw conveyor blade portion 70 is provided having a first total diameter equal to an inner surface diameter of the conduit. The first screw conveyor blade portion 70 has a first blade-root profile for operating at a first discharge range. A second screw conveyor blade portion (not shown) is also provided having a first total diameter equal to an inner surface diameter of the conduit. The second screw conveyor blade portion has a second blade-root profile for operating at a first discharge range. For example, the first screw conveyor blade portion may have the blade-root profile shown in
As shown in
As such, the screw conveyor portions are modular and interchangeable. As shown in
In order to power the mixing portion 11 and the screw conveyor 50, a power distribution area is shown in
Another advantage of this technology is that multiple modular screw conveyor portions can be utilized to control the material flow. For example, a hopper screw conveyor module can be installed under the hopper 10 portion to load the conduit with powdered material. A second screw conveyor flight module can be coupled to the first screw conveyor flight module. This second screw conveyor flight module can have the same root-blade profile as the first screw conveyor flight module or can have a different root-blade profile. The selection of the proper root-blade profile will depend on the material to be dispensed and the specific application. For example, in seed treatment implementations, the amount of dry agrochemical material dispensed may vary depending on the type of agrochemical and the seed treatment rate.
The root-blade profile can be altered to provide flow volume and flow rate. For example, the screw conveyor can comprise a plurality of spiral blades—an increase in blade-frequency—which provides a more rapid rate of horizontal travel per rotation than a single spiral blade.
In seed treatment implementations, the fluent material dispenser may dispense dry agrochemical additives such as talc or graphite. The hood 37 of the discharge aperture prevents material from flowing into the conduit. The treated seed is wet and sticky. The hood prevents the wet, sticky seed from entering the conduit and blocking the flow of the powdered agrochemicals.
The control system 200 can be coupled with the motor to adjust the dispensing rate. The control system regulates the speed of the screw conveyor. For example, a motor may be directly connected to a first beater, with a sprocket gear for receiving a chain for driving both a second beater and the screw conveyor. By regulating the speed of the motor, the speed of the beaters and the speed of the screw conveyor are affected. In another embodiment, a separate motor is coupled to the screw conveyor to independently control the speed of the screw conveyor relative to the speed of the first beater and the second beater.
For use with a seed treatment applicator, the horizontal conduit can be inserted through the discharge opening or the inlet opening of the mixing drying drum. The fluent material dispenser can be mounted to a hydraulic lift cart
In one embodiment, the length of the spacing element is 1.5 inches. In another embodiment, the length of the spacing element is less than 6 inches. In another embodiment, the length of the spacing element is between 0.5 inches and 3 inches.
We also disclose a method for the even dispensing of a metered quantity of powder, the apparatus comprising:
In one embodiment, the screw conveyor, spacing element, and knife assembly 85 are integrally formed. The screw conveyor, spacing element, and knife assembly 85 can be made of plastic or metal. In another embodiment, a screw conveyor module portion is integrally formed with the spacing element 100 and the knife assembly 85. Integrally forming these portions prevents the material backfill pressure from displacing the knife assembly 85.
The screw conveyor can consist of a narrow root shaft with elongated spiral blades. Alternatively, the screw conveyor can consist of a wide root shaft with narrow spiral blades. The wide shaft embodiment provides the advantage of decreasing the flow rate of material compared with a narrow shaft screw conveyor through conduits of similar diameter. In order to achieve similar flow rates with the wider shaft, the motor needs to turn the screw auger at a higher number of rotations per minute. By powering the knife assembly 85 on the same rotating shaft as the auger, the number of rotations per minute of the knife assembly 85 also increased. In another embodiment, a distal portion of the screw conveyor can comprise a plurality of spiral blades.
In one embodiment, the conduit 20 has an internal diameter of 2.06″. The vanes of the knife assembly 85 have an outer diameter of 1.94″. This allows a 0.06″ radial gap between the distal end of the individual vanes of the knife assembly 85 and the internal surface of the conduit 20. The size of the conduit 20 and length of the vanes 90 of the knife assembly 85 are variable. In another embodiment, the discharge aperture 35 is configured such that its proximal longitudinal edge is slanted. The knife assembly 85 is aligned with the most proximal portion of the discharge aperture 35. In another embodiment, the discharge aperture comprises a 180-degree opening along a longitudinal portion of the conduit. The 180-degree opening is oriented 45 degrees from horizontal. In this configuration, the conduit is closed in 45-degree portion below horizontal on the trailing portion, as determined by the rotation of the vanes of the knife assembly 85. As the knife assembly 85 rotates, the fluent material is pushed toward the open portion of the discharge aperture 35. In another assembly, the 180-degree opening of the discharge aperture 35 is the lower 180-degrees of the conduit 20.
In an embodiment with a 2-inch internal diameter conduit, the throughput of fluent material can range from 0.125 to 120 ounces per minute. The rate depends on the size of the conduit, the root-blade profile of the screw conveyor, and rotational speed of the screw auger.
In one embodiment, the spacing element 100 provides a transition space between the screw conveyor 50 and the knife assembly 85. In this transition space, the spiral blades do not directly contact the fluent material. This transition space may stabilize the flow of the fluent material before the material contacts the knife assembly 85. In one embodiment, the spacing element 100 has the same diameter as the central collar of the knife assembly 85. In another embodiment, the spacing element 100 has the same diameter as the root 52 of the screw conveyor 50.
In one embodiment, the spacing element 100 and knife assembly 85 are integrally connected as a unified flow equalizer, as shown in
In another embodiment, the dispenser is mounted to an adjustable portable support stand. The stand is mounted on wheels, as shown in
It is understood that other embodiments will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments are shown and described by way of illustration only. As will be realized, the concepts are capable of other and different embodiments and their several details are capable of modification in various other respects, all without departing from the spirit and scope of what is claimed as the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
This application claims the benefit of U.S. Provisional Application No. 62/312,237, filed Mar. 23, 2016.
Number | Date | Country | |
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62312237 | Mar 2016 | US |