AU777985B2 - Apparatus and method for applying liquid droplets to a particulate material - Google Patents

Description

WO 01/70410 WO 01/04 10PCT/AUOI/00276 APPARATUS AND METHOD FOR APPLYING LIQUI1D DROPLETS TO A PARTICULATE MATERIL Background of the Invention The present invention relates to an apparatus and method for applying liquid droplets to a particulate material.

Description of the Prior Art The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

It is presently known to utilise various forms of spraying devices for the distribution of herbicides, fungicides, fertilisers, etc. Generally, such spraying devices are adapted to spray a relatively high volume of diluted chemical.

More recent methods of increasing the efficiency of such spraying devices include the utilisation of rotary atomiser discs, also known as centrifugal energy nozzles, spinning disc atomisers, or merely spinning discs. Such discs allow a reduction in the volume of chemical liquid or spray utilised, by delivering of low volumes of highly concentrated herbicide, fungicide, fertiliser, etc. These discs operate by spinning at relatively high speed to produce droplets of relatively uniform size, the chemical being fed onto the rotary atomiser disc at a substantially central portion thereof such that the liquid is reduced to small droplets as it moves towards the outside of the disc by centrifugal force. Typically, the rotational speed of the disc is between 2000'to 5000 revolutions per minute. Some discs presently used have fine grooves etched in the upper surface thereof, radiating out from the central portion to the extremities thereof so as to enhance the generation of substantially even droplets. Typically, the diameter of such discs is between 5 and 10 cm.

It will be appreciated that such controlled drop applicators have a liquid holding capacity governed by the diameter of the disc and the speed at which the disc is rotated. In WO 01/70410 PCT/AU01/00276 -2practice, the speed of rotation is usually not varied, and the liquid holding capacity is therefore dependent on the upper surface area of the disc. Unfortunately, when the disc becomes overloaded with liquid, the surplus liquid flows over the edge of the rim of the disc.

The Applicant of the present invention previously invented an apparatus which overcame many of the disadvantages and aforementioned problems of the prior art.

The Applicant's previous invention, as granted in Australian Patent No. 640546, and US Patent No. 5,246,167, defines a droplet applicator which has a plurality of fibres extending substantially perpendicularly to the axis from a substantially cylindrical shaped hub, to form a substantially disc-shaped device. In that device, the density of the fibres was progressively increased from an upper surface of the disc-shaped device, towards the lower surface. In use, when a liquid is supplied to the upper surface, the disc-shaped device is rotated, such that droplets of the liquid are dispersed from the fibres. Some of the liquid is dispersed from the fibres adjacent the upper surface, and the remainder of the liquid is progressively dispersed by the fibres adjacent the lower surface.

The Applicant's previous invention was particularly related to a device for the distribution of liquid pesticides, herbicides, fungicides or fertilisers from a wand like apparatus, the liquid being supplied in a backpack arrangement, as illustrated in Fig. 1.

A detailed view of the disc-shaped device is shown in Fig. 2.

Whilst the Applicant's earlier invention provides significant advantages over prior art droplet applicator devices for the spraying of liquid pesticides, herbicides, fungicides or fertilisers or the like, it is particularly suited to the application of such liquid to vegetation and/or a substrate surface.

The Applicant's earlier invention is not necessarily suited to the application of liquid droplets to particulate materials, such as seeds and grains.

In consideration of the disadvantages of the prior art, the Applicant has therefore WO 01/70410 PCT/AU01/00276 -3devised an apparatus and method which is particularly suited to the application of liquid droplets to particulate materials, such as, but not limited to, seeds and grains.

Summary of the Invention The present invention seeks to provide an apparatus for applying liquid droplets to a particulate material, such as, but not limited to, seeds and grains.

In one broad form, the present invention provides an apparatus for applying liquid droplets to a particulate material, said device including: an axially rotatably disc-shaped device to which a liquid is adapted to be supplied, such that, as said device is rotated, said droplets of said liquid are sprayed generally outwardly therefrom; means for supplying said particulate material, in a generally separated manner, past said disc-shaped device in a direction generally transverse to that in which said liquid is sprayed, such that said droplets become applied to said particulate material.

Preferably, said disc-shaped device is a substantially solid disc device, optionally having etched grooves, or similar, in an upper surface thereof.

Alternatively, but also preferably, said disc-shaped device includes a plurality of fibres extending substantially outwardly from an axial portion of said disc-shaped device.

In this form, preferably, the density of said fibres increases progressively from a first side of said disc to a second side thereof, wherein, in use, some of said liquid is dispersed from the fibres adjacent said first side, and the remainder of said liquid is progressively dispersed by the fibres adjacent the second side of said disc.

Also preferably, said second side of said device is provided with a heavy concentration of said fibres such that it is substantially impervious to said liquid.

Preferably, said disc-shaped device is rotated by an electric motor.

WO 01/70410 PCT/AU01/00276 -4- In a preferred form, the apparatus further includes a housing, within which said discshaped device is provided substantially centrally, wherein said particulate material ingresses through a first end of said housing and egresses through a second end of said housing.

The apparatus preferably includes a separator means provided upstream relative to said disc-shaped device, to separate said particulate material supplied via said first end of said housing.

Preferably, said separator means is embodied as a plate-like device.

Also preferably, the axis of said disc-shaped device is substantially vertical, and, said particulate material falls past said disc-shaped device by gravitational forces.

Preferably, said liquid is supplied from a container to said disc-shaped device by gravitational forces, by utilising a hand operated pumping devices, under pressurisation provided within said container, and/or via an electric, mechanical or hydraulic pumping device or the like.

Also preferably, said apparatus is supplied intermediate aa delivery system and a storage container.

In a preferred form, said apparatus is portable.

In a preferred embodiment, said liquid is an insecticide, fungicide, fertiliser, a biological inoculant, or like liquid.

Preferably, said particulate material is seed, grain, or like particulate material.

In a further broad form, the present invention provides a method of applying liquid droplets to a particulate material, including the steps of: WO 01/70410 WO 01/04 10PCT/AUO1/00276 supplying said particulate material to fall. in a generally separated manner; spraying liquid droplets from a rotating disc-shaped device provided intermediate of said falling particulate material, such that said droplets become applied to said particulate material.

Brief Description of the Drawing The present invention will become more fully understood from the following detailed description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein: Fig. 1 illustrates the apparatus of the Applicant's earlier invention; Fig. 2 details of the disc-shaped device, utilised in the apparatus of Fig. 1; and, Fig. 3 illustrates a preferred embodiment of the apparatus in accordance with the present invention.

Detailed Description of Preferred Embodiments Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated: Figs. 1 and 2 illustrate a prior art apparatus in accordance with the Applicant's earlier invention, the subject of Australian Patent No. 640546 and US Patent No. 5,246,167. As shown in the drawings, a user 1, holds the apparatus 2, used for the supply and distribution of liquid herbicide, fuangicide or pesticide. The apparatus 2 includes a droplet applicator 3 provided at one end of a wand 4 to supply chemical liquid from a container 5. The device is particularly useful for supplying liquid over vegetation, or, a substrate surface.

In Fig. 2 is illustrated an enlarged view of the droplet applicator device 3, and is shown including a disc-like member 7 which is formed of a central hub 8 having a plurality of fibres 9 extending therefrom in a radial manner. The central hub 8 is connected via a shaft to an electric motor 11, which facilitates the rotation of the disc-like member 7. The motor 11I is attached via a support 12 to the wand 4.

WO 01/70410 WO 01/04 10PCT/AUOI/00276 -6- Liquid pesticide, herbicide, or fungicide is supplied within the wand 4 via tubing 13 to the upper surface 14 of the disc 7. The liquid 15 is then supplied towards the central portion of the disc 7, such that, during rotation of the disc about the shaft 10, the liquid flows under the action of centrifugal forces along the fibre elements 9, such that the centrifugal forces fling droplets out along the fibres in a narrow spectrum of size to the rim and beyond.

Some of the liquid will pass down through the fibres towards the lower surface 16 and gradually be dispersed by each end of the fibres as it travels towards the lower surface member 16. In this arrangement, the density of the fibres increases from the upper end 14 to the lower end 16, to an extent where the lower end 16 is virtually liquid-proof, and droplets are flung from the increasingly less pervious lower layers, rather than leaking through the bottom.

In use, the disc and accompanying motor are mounted on the end of a wand 4, such that liquid can flow from a backpack arrangement under gravitational forces.

The apparatus, in accordance with the present invention, as illustrated in Fig. 3, utilses a sin-War disc-shaped device 20, to which liquid is supplied through delivery tube and nozzle 21, from a container 22. The liquid may be supplied under the forces of gravity, or, from a pressurised container, or, by utilising a mechanical or electric or hydraulic pumping means. The spinning disc may be rotated by means of an electric motor 23. Particulate material, such as seeds or grains, are supplied through a first end 25 of a housing 27, for instance, via a seed delivery system 28. Grain or seed 29 then falls under the forces of gravity in a manner substantially as illustrated through the first end of the housing 25 towards the second end 26 of the housing, and may then be supplied into a seed container 30. To facilitate the separation of the particulate material, a spreader plate 24 may be provided such that as the seed falls and hits the spreader plate, it is directed over the edges of the spreader plate, towards the second end 26 of the housing 27. As the seed of grain passes past the intermediate portion of the housing 31, and generally past the spinning disc 20, liquid droplets being sprayed generally outwardly of the spinning disc 20 become applied to the particulate material.

Whilst the embodiment illustrated in Fig. 3 shows a spinning disc which may be of WO 01/70410 PCT/AU01/00276 -7a form as described in the Applicant's previous invention, whereby a plurality of fibres extend substantially outwardly from the axial portion of the disc-shaped device, the disc-shaped device may alternatively be embodied as a substantially solid device.

It will also be appreciated that whilst the apparatus described in Fig. 3 is generally provided in a manner between a seed delivery system 28 and a seed container 30, such that the flow of the particulate material and the liquid to be applied thereto may be provided under the forces of gravity due to the orientation of the device, the device need not necessarily be oriented in this manner. The means for supplying the seed or grains or other particulate material, together with means for supplying the liquid to be applied thereto may, alternatively, be supplied using mechanical, electrical and/or hydraulic forces, particularly if the apparatus is disposed in such a manner that gravitational forces cannot be partially or fully utilised.

It will be appreciated to persons skilled in the art, that liquid supplied in the apparatus of the invention may include insecticides, fungicides, fertilisers or biological inoculants, and the particulate material may preferably be grains, seeds or the like. The present invention should not, however, be considered to be limited to such liquids and particulate material As such, any particulate material which is required to have a liquid provided thereto in a spray like manner, can be embodied in accordance with the present invention.

It will be appreciated by persons skilled in the art that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art, should be considered to fall within the scope of the invention as broadly hereinbefore described and as hereinafter claimed.

Claims (18)

1. An apparatus for applying liquid droplets to a particulate material, said device including: an axially rotatably disc-shaped device to which a liquid is adapted to be supplied, such that, as said device is rotated, said droplets of said liquid are sprayed generally outwardly therefrom; means for supplying said particulate material, in a generally separated manner, past said disc-shaped device in a direction generally transverse to that in which said liquid is sprayed, such that said droplets become applied to said particulate material.

2. An apparatus as claimed in claim 1, wherein said disc-shaped device is a substantially solid disc device, optionally including etched grooves, or similar, in an upper surface thereof.

3. An apparatus as claimed in claim 1, wherein said disc-shaped device includes a plurality of fibres extending substantially outwardly from an axial portion of said disc-shaped device.

4. An apparatus as claimed in claim 3, wherein the density of said fibres increases progressively from a first side of said disc to a second side thereof, wherein, in use, some of said liquid is dispersed from the fibres adjacent said first side, and the remainder of said liquid is progressively dispersed by the fibres adjacent the second side of said disc.

An apparatus as claimed in claim 4, wherein said second side of said device is provided with a heavy concentration of said fibres such that it is substantially impervious to said liquid.

6. An apparatus as claimed in any one of claims 1 to 5, wherein said disc-shaped device is rotated by an electric motor.

7. An apparatus as claimed in any one of claims 1 to 6, further including: a housing, within which said disc-shaped device is provided substantially WO 01/70410 PCT/AU01/00276 -9- centrally, wherein said particulate material ingresses through a first end of said housing and egresses through a second end of said housing.

8. An apparatus as claimed in claim 7, further including: a separator means provided upstream relative to said disc-shaped device, to separate said particulate material supplied via said first end of said housing.

9. An apparatus as claimed in claim 8, wherein said separator means is embodied as a plate-like device.

An apparatus as claimed in any one of claims 1 to 10, wherein the axis of said disc- shaped device is substantially vertical, and, said particulate material falls past said disc-shaped device by gravitational forces.

11. An apparatus as claimed in any one of claims 1 to 11, wherein said liquid is supplied from a container to said disc-shaped device by gravitational forces, by utilising a hand operated pumping devices, under pressurisation provided within said container, and/or via an electric, mechanical or hydraulic pumping device or the like.

12. An apparatus as claimed in any one of claims 1 to 11, wherein said apparatus is supplied intermediate a delivery system and a storage container.

13. An apparatus as claimed in any one of claims 1 to 11, wherein said apparatus is portable.

14. An apparatus as claimed in any one of claims 1 to 13, wherein said liquid is an insecticide, fungicide, fertiliser, a biological inoculant, or like liquid. An apparatus as claimed in any one of claims 1 to 14, wherein said particulate material is seed, grain, or like particulate material.

WO 01/70410 PCT/AU01/00276

16. A method of applying liquid droplets to a particulate material, including the steps of: supplying said particulate material to fall in a generally separated manner; spraying liquid droplets from a rotating disc-shaped device provided intermediate of said falling particulate material, such that said droplets become applied to said particulate material.

17. An apparatus for applying liquid droplets to a particulate material, substantially as herein described with reference to the accompanying drawings.

18. A method of applying liquid droplets to a particulate material, substantially as herein described.