Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR APPLYING LIQUID
DROPLETS TO A PARTICULATE MATERIAL
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
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practice, 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
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devised 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. -
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In a preferred form, the apparatus further includes a housing, within which
said disc-
shaped 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 ofe
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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 Drawings
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, fungicide 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
10 to an electric motor 11, which facilitates the rotation of the disc-like
member 7. The
motor 11 is attached via a support 12 to the wand 4.
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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,
utilises a similar 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
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a 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.
