Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a method and apparatus for distributing
flowable material and has particular application to the distribution of
chemical aids onto, or into, growing crops.
It is well known in the art to distribute a flowable material
by centrifuging the material from the periphery of a rotary member
and in, for example, our Canadian Patent No. 1,023,987 there is
disclosed an embodiment wherein two rotary members of substantially
identical shape and configuration are mounted one above the other on a
substantially vertical shaft and rotated at uniform speed. Flowable
material is supplied to the upper rotary member, is centrifuged fm m
the periphery thereof to produce a spray pattern substantially uniform-
ally disposed about the axis of rotation of said member, the spray
pattern from said upper rotary member is interrupted at a plurality of
locations spaced about the axis of rotation of the member, and the
interrupted flcwable material is conducted to the second rotary member
and constitutes the flowable material feed thereto, the flowable material
supplied to the lower rotary member being centrifuged frcm the periphery
thereof without interruption. By carefully selecting the locations and
angular extent of the interrupting locations, relative to the direction
of displacement of the apparatus over the ground, the uninterrupted
spray pattern frcm the upper rotary member superimposed on the uniform
spray pattern frcm the lower rotary member can produce a substantially
uniform distribution of flowable material transverse to the direction of
displacement.
It is also well known in the art that the droplet size distributed
from the periphery of a rotary member is directly related to the peripheral
speed of the edge of the rotary member frcm which the material is centrifuged
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the configuration of said edge, and the rate at which the material i6
distributed fro~ s~id periphery. The shape and configuration is important
and, in practice, it is advantageous to uniformly radially disrupt the
peripheral edge by castellation, notching, serration, or ridging to
assist droplet formation and 6uch forms of edge disruptions are hereafter
referred to a~ radial disruptîons. To obtain a uniform si~e of droplet
with uniform dietribution of droplets in the spray pattern circumferentially
of the rotary member the rotary member must have a peripheral speed within
a relatively 6mall speed range, and the rate of distribution of flowable
material from the rotary member must also be maintained within a relatively
narrow range. This means, in fact, that for a given diameter of periphery,
the rotational speed of the rotor to afford uniform distribution with
uniform droplet 6ize for a given viscosity of flowable material can be
readily determined and it then becomes necessary only to supply flowable
material to the rotary member at a uniform rate commen6urate with the
peripherAl speed of the rotary member. This also mean6 that, for a given
flowable material, with a given diameter of the periphery of the rotary
member and the given rotational apeed, the rate at whioh the flowable
material can be di6tributed from the rotor i6 severely limited if a
de6ired particle or droplet size iB to be obtained.
It will thus become apparent from the above that whilst masking a
single rotary member to interrupt part of the spray pattern i66uing
therefrom and ducting the interrupted flowable material to an unmasked
rotary member CAn afford a 6ubstantially unif~rm distribution of flowable
material at the ground tran~ver~e to the direction of displacement of
the apparatus there is a severe limitation on the rate at which flowable
material can be distributed from the apparatus.
The pre6ent invention 6eek~ to provide a method for di6tributing
flowable materiAl from rotary members mounted on a common rotational
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According to the present invention there is provided a
method for distributing flowable material from a continuous periphery
of each of a plurality of rotating me~bers arranged in spaced
parallel relationship and rotating about a substantially vertical
axis passing through the centre of each rotary member, each rotary
member, other than the bottom rotary member, having a plurality of
openings therethrough spaced about a pitch circle common to all the
rotary members, comprising the steps of rotating said rotary members
at a substantially uniform speed,-directing a stream of flowable
material generally parallel to the rotational axis of the rotary
members and spaced from the rotational axis by the radius of said
common pitch circle, and so arranging the circumferential positions
of the openings in each rotary member above the bottom member
relative to the openings in the other rotary members that all the
parts of each rotary member between said openings are exposed
successively to the undeflected stream of flowable material to
deflect material from said stream and the openings in each rotary
member above the bottom rotary mem~er are successively rotated into
the path of the stream to allow said stream to flow undeflected
therethrough, centrifuging material deflected from the stream by
each rotary member with openings from the said continuous periphery
of that rotary member and centrifuging the undeflected stream
. flowing through the openings in the lowermost rotary member with
openings from the continuous periphery of the bottom rotary member.
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The invention also provides apparatus for distributing
flowahle material comprising a plurality of rotatable members
arranged in spaced parallel relationship and rotatable about
a substantially vertical axis passing through the centre of each
rotary member, each rotary member, other than the bottom
rotary member, having a plurality of openings therethrough
spaced about a pitch circle common to all the rotary members,
means for rotating said rotary members at a substa ntially
uniform speed, means for directing a stream of flowable
material generally parallel to the rotational axis of the
rotary members and spaced from the rotational axis by the
radius of said common pitch circle, the circumferential
positions of the openings in each rotary member above the
bottom member relative to the openings in the other rotary
members being such that all the parts of each rotary member
between said openings are exposed successively to the
undeflected stream of flowable material to deflect material
from said stream and the openings in each rotary member
above the bottom rotary member are successively rotated
into the path of the stream to allow said stream to flow
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undeflected therethrough, whereby material deflected from
the stream by each rotary member with openings is
centrifuged from the said continuous periphery of that
rotary member and the undeflected stream flowing through
the openings in the lowermost rotary member with openings
is centrifuged from -the continuous periphery of the
bottom rotary member.
Each rotary member may comprise an annular
base surrounded by a wall, said wall defining the periphery
from which the flowable material is centrifuged, said
wall sloping radially outwardly from said annular base,
and said wall including a substantially uniform radial
disruption around the peripheral edge from which the
material is centrifuged.
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The openings of each rotary member may be of
equal configuration and equally spaced around said pitch
circle.
Certain of the rotary members may be surrounded
by a mask which obstructs spray patterns issuing from the
rotary members, with other rotary members being outside
the mask.
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The invention will now be described further by way of
example with reference to the accompanying drawings in which:-
Fig. 1 shows, diagrammatically, a development illustrat-
ing one method for supplying flowable material from a single
st:ream to four distribution members,
Fig. 2 shows a vertical cross section through an assembly
for distributing flowable material on the llne II - II in Fig. 3,
Fig. 3 shows a cross section through the apparatus on
the line III - III in Fig. 2,
Fig. 4 shows, on an enlarged scale, a cross section through
the mid-region of the uppermost rotor in the assembly
illustrated in Figs. 2 and 3 on the line II - II in Fig. 3, and
Fig. 5 shows an arrangement for supporting a plurality
of assemblies of the type illustrated in Figs. 2 and 3.
In the development illustrated in Fig. 1 four rotary
members 11, 12, 13, and 14 arranged in spaced apart parallel
relationship are to be considered as moving in unison from
right to left as viewed in Fig. 1 and said members are to be
supplied with flowable material from a stream S issuing from
a duct 15 above the distribution member 11 with the axis of
stream S perpendicular to the planes of the distribution
members 11, 12, 13 and 14.
The rotary member 11 presents, in the path of stream S,
catchment surfaces lla spaced apart by openings 11_ through
member 11, the length of each surface lla presented to the
stream S being one third of the length of each opening 11_
presented to the stream S. Members 12, 13 and 14 are
constructed in identical manner to member 11 and thus member
12 presents catchment surfaces 12a separated by openings 12_,
member 13 presents catchment surfaces 13_ separated by openings
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13_ and member 14 presents catchment surfaces 14a separated
by openings 14b As will be seen from Fig. 1 the trailing
edge of each catchment surface 14a lies vertically beneath
lhe leading edge of a catchment surface 13a, the trailing
edge of each catchment surface 13a lies vertically beneath
the leading edge of a catchment surface 12a, and a trailing
edge of each catchment surface 12a lies vertically beneath
the leading edge of a catchment surface lla and, as the length
of each catchment surface lla, 12a, 13a, and 14a is equal to
one third of the openings llb, 12b, 13b and 14b the trailing
edge of each catchment surface 11_ lies vertically above the
leading edge of a catchment surface 14_.
With the arrangement described above, and with the members
11, 12, 13 and 14 in the above described arrangement displacing
at substantially uniform speed from right to left as viewed
in Fig. 1 and with the duct 15 supplying flowable material
to maintain stream S at a substantially uniform rate of delivery,
the displacement of member 11 causes catchment surfaces 11_
to successiv.ely deflect flowable material from the stream S
and, between successive catchment surfaces 11_ the stream S
flows uninterrupted through the openings 11_ in member 11.
When a catchment surface 12_ lies in the path of stream S
; said surface 12_ deflects flowable material for distribution
by the member 12, in the absence of a catchment surface lla
. or 12a in the path of stream S the stream S passes through
the openings 11_ and 12b in members 11 and 12 respectively
and, when a catchment surface 13_ lies in the path of stream
. S said surface deflects the stream S, the deflected stream
S constituting the supply of flowable material to be distributed
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by the member 13 and, when no surface lla, 12a or 13a lies
in the path of stream S the stream S flows, undeflected,
through an opening llb, 12b and 13b to strike, and be deflected
by, a catchment surface 14a of the member 14. By this means
the stream S is interrupted by the catchment surfaces 11_, 12_,
13a and 14a to define the supply of flowable material for
distribution by the members 11, 12, 13 and 14 respectively
and, because of the length of surfaces lla, 12a, 13a and 14a
presented to the stream S relative to the length of openings
llb, 12b, 13b and 14b, the flowable material directed to the
members 11, 12, 13 and 14 is substantially uniform so that
each member 11, 12, 13 and 14 distributes exactly the same
volume of flowable material as the other members.
It will be appreciated that whilst the member 14 has been
illustrated as identical with members 11, 12 and 13 by
catchment surfaces 14a separated by openings 14_ the openings
14b are never exposed to the stream S, the surfaces 11 , 12a
and 13a deflect 75% of the stream S and therefore the stream
S flowing to the member 14 constitutes only 25% of the total
volume of flow from duct 15. Thus, as there is no progression
of the stream beyond member 14 the member 14 may be a plain.
member without openings 14_ therethrough.
It will be appreciated that whilst the stream S has, for
convenience, been shown in the Fig. 1 embodiment as being
perpendicular to the plane of members 11, 12, 13 and 14 it
is often advantageous to incline the stream S to the plane
of members and to adjust the relative positions of the catch-
ment surfaces lla, 12a, 13a and 14a to obtain the desired
distribution of the stream S to the members 11, 12, 13 and 14.
When the stream S is inclined to the plane of members 11, 12,
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13 and 14 said stream may be inclined to have a velocity
component in the direction of members 11, 12, 13 and 14,
whereby the relative difference in speed between the catchment
surfaces lla, 12a, 13a and 14a and the stream S is reduced.
It will also be apparent that Fig. 1 shows a development
of members 11, 12, 13 and 14 and, in practice, the members
11, 12, 13 and 14 will be so arranged, and the direction of
stream S so arranged, that all flowable material deflected
by a member 11, 12, 13 or 14 is retained by that member and
centrifuged from the periphery of that member.
In the embodiment shown in Figs. 2 and 3 a mask, generally
identified by numeral 21, presents upper and lower bearings 22
and 23 respectively and the drive shaft 24 of an electric
motor 25 mounted on the mask 21 extends downwardly through
upper bearing 22 and lower bearing 23 to project from the lower
end of the mask 21. The shaft 24 has six rotary members 26,
27, 28, 29, 30 and 31 secured thereon in vertically spaced
relationship with the members 26, 27, 28 and 29 located within
the upper regions of mask 21 and the members 30 and 31 beneath
the mask 21.
The mask 21 comprises a cylindrical section 32, closed at
its upper end by an annular cover 33 upon which the motor 25
is secured, and an inverted truncated cone section 34 depending
from the lower regions of the section 32. The lower end of
the section 34 is closed by an end wall 35 parallel to the cover
33 and a cylindrical skirt 36 depends downwardly from section
34 to shield the rotary members 30, 31.
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Flowable material is supplied to the apparatus from an
external source, (not shown), by a conduit 37, extending through
the cover 33 to discharge flowable material towards rotary
member 26. The conduit 37 is inclined to the plane of the
bottom of member 26 in such manner that the flowable material
discharged through conduit 37 has a horizontal component
opposite to the direction of displacement of that part of
member 26 adjacent conduit 37. A duct 38 supported by wall
35, allows flowable material in the lower regions of cone
section 34 to discharge towards the rotary member 30.
The cylindrical section 34 of the mask 21 has two slots
39 and 40 located to allow flowable material distributed from
the periphery of rotary members 26, 27, 28 and 29 to pass
therethrough. The slot 39 has an arcuate length "A" of 1006',
the slot 40 has an arcuate length "B" of 7722', and the
two interrupting sections of the mask 11 between the slots 39
and 40 each has an arcuate length of 9116'. The two slots
39 and 40 may be of uniform width as illustrated or of variable
width to afford for each rotary member a slot width individual
thereto.
Thus, when the apparatus is operating and rotary members
; 26, 27, 28, 29, 30 and 31 are rotating in the direction of the
arrow "E" shown in Fig. 3, and with flowable material supplied
e~ually and at constant rate to members 26, 27, 28, 29, 30 and
31, some 49.3% of the material supplied to members 26, 27, 28
and 29 is distributed through slots 39 and 40 whilst some
50.7% is interrupted by the sections between slots 39 and 40,
and the interrupted 50.7% of flowable material flows down the
inside of mask 21 and is released through the duct 38 for
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distribution by members 30 and 31. Thus, members 30 and 31
receive some 50.7% of the total volume of material supplied
by the conduit 37 for distribution therebetween.
To assist in a sharp cut-off at the leading and trailing
edges of slots 39 and 40 and to prevent breakdown of the droplets
striking said edges of said slots, it has been found advantageous
to provide deflector plates 39b and 40a, 40_ at the leading
and trailing edges of slots 39 and 40 respectively.
The rotary members 26, 27 and 28 are of generally identical
construction and therefore the general description will be
limited to the following description of member 26 and it will
be understood that the other members 27 and 28 have the same
parts and construction. Thus, the member 26 comprises a
relatively flat annular base 26a with a central bush 26_,
through which the drive shaft 24 passes, and a peripheral wall
26c inclined upwardly and outwardly from the base 26a. The
inside surface of the wall 26c includes means for assisting
uniform distribution of the material flowing towards the
periphery in the form of ribs 26d extending from the base surface
26a to the periphery of wall 26c and a toothed flange defines
a radial disruption for the peripheral edge 26~ of wall 26_.
The base 26a has four holes 26e, 26f, 26~ and 26_ there-
through arranged on a pitch circle concentric with the rotational
axis of member 26. The axis of the stream of flowable material
passes substantially through the pitch circle of the holes
26e, 26f, 26g and 26h.
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The holes 26e, 26f, 26g and 26h through rotor 26 have such
length, circumferentially of the p tch circle, that the four
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surfaces of base 26a presented successively to the stream of
material from duct 37 deflect 25% of the stream for distribut-
ion by the member 26, said material being centrifuged over the
base 26a, up the wall 26c and over the periphery thereof when
the shaft 24 is rotating the rotary members 26, 27, 28, 29,
30 and 31, at operational speed. The member 27, identical to
member 26, has its respective holes 27_, 27f, 27_ and 27h
offset from the holes 26e, 26f, 26_ and 26 respectively so
that the surfaces therebetween are exposed to the material
stream directed through holes 26e, 27f, 26g and 26_ thus to
deflect part of the stream for distribution from the periphery
; of member 27. In like manner the member 28 presents its surfaces
between holes 28_, 28f, 28g and 28h to the stream passing
through holes 27e, 27f, 27~ and 27_ and that part of the stream
not deflected by members 26, 27 and 28 passes through the
holes 28e, 28f, 28~ and 28h to the member 29, which is identical
: in construction to members 26, 27 and 28 with the exception
that member 29 does not have holes through its base 29a.
With the above described arrangement member 26 deflects
: 20 25~ of the flowable material stream directed thereto by
conduit 37, member 27 deflects 33 1/3% of the stream directed
thereto through holes 26e, 26f, 26g and 26 , member 28 deflects
50~ of the stream directed thereto through holes 27_, 27f,
27g and 27h and that 50% of the stream undeflected by member
28 passes through openings 28e, 28f, 28_ and 28_ to member 29.
Thus, each rotary member receives 25% of the total volume of
flowable material supplied by conduit 37 for distribution
from its periphery and thereby the volume distributed from the
rotary members 26, 27, 28 and 29 is equal.
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To assist in obtaining a sharp cut-off for the deflected
stream each hole through a member 26, 27 and 28 is countersunk
as illustrated for holes 26_ and 26_ in Fig. 4.
The flowable material spray from the rotary members 26,
27, 28 and 29 is interrupted by the mask 21 between slots 39
and 40 and the interrupted material flows down the internal
surfaces of the mask 21 to the bottom of cone section 34 for
release through duct 38.
The rotary member 30 directly beneath the mask 21 is
identical in construction to member 26 with the exception that
its four holes (only holes 30_ and 30g are shown in Fig. 2)
have such diameters that member 30 deflects 50% of the stream
of flowable material supplied thereto by the duct 38 for release
at its periphery, the remaining 50% of the stream passing
through the holes in member 30 to the member 31, which is
identical to rotary member 29 and does not have holes through
its base. The holes in member 30 may be countersunk in like
manner to the holes in members 26, 27 and 28.
As the rotary members 26 to 31 inclusive are mounted for
rotation at the same rotational speed and have the peripheries
of their respective side walls 26_ to 31_ inclusive of the same
diameter the peripheral speeds at the material centrifuging
periphery is the same. Further, as the rotary members 26, 27,
28 and 29 each receive 25% of the total volume of flowable
material from conduit 37 and as some 50% of the flowable
; material centrifuged from members 26, 27, 28 and 29 is interr-
- upted by the mask 21 and constitutes equal feed to rotary
members 30 and 31, then the volume of flowable material from
the peripheries of the members 26 to 31 inclusive is substan-
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tially the same and, with uniform volumetic flow from the
members 26 to 31 and uniform peripheral speeds, a substantially
uniform droplet size is obtained in the spray pattern
externally of the mask 21.
If now the assembly is supported above a base surface
and traversed over the base surface with the slots 39 and 40
so located relative to the direction of displacement that the
spray patterns from said slots 39 and 40 each lie, at ground
level, equally on each s.ide of the plane in the direction of
displacement and passing through the axis of shaft 24, and said
spray patterns, superimposed on the spray patterns from rotors
30 and 31, produce at ground level a substantially uniform
distribution of flowable material transverse to the direction
of displacement.
Fig. 5 shows one form of apparatus for supporting and
displacing a plurality of assemblies of rotary members, each
constructed and arranged in identical manner to the assembly
illustrated in Figs. 2 and 3.
Thus, in the Fig. 5 embodiment a chassis 50, supported on
wheels 51 and 52, supports a tank 53 of flowable material which
discharges to a manifold 54. Manifold 54 discharges via
conduits 37 to three assemblies 55, 56 and 57, supported by
a rail 58 from chassis 50. Chassis 50 also support batteries
59, 60, 61 and 62 for supplying power to the electric motors
25 of assemblies 55, 56 and 57.
In operation, the apparatus is towed over the ground to
be treated at uniform speed, the conduits 37 supply flowable
material from manifold 54 to the assemblies 55, 56 and 57,
the rotor assemblies 26 to 31 inclusive of the assemblies
~30 55, 56 and 57 are rotated at such speed that each rotor
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centrifuges the material applied thereto uniformly from its
periphery and, as the transverse spacing of the assemblies
55, 56 and 57 is adjusted so that the spray patterns touch,
or just overlap, at ground level, a substantially uniform
distribution of flowable material transverse to the direction
of displacement is obtained.
It will be appreciated that the method and apparatus for
dispensing the flowable material to the rotors allows each
rotary member to receive its designated share direct from the
stream and the flowable material delivered on a surface between
the holes is immediately deflected by the rotation of the rotary
member outwardly of the annular region within which the holes
are located so that, the flowable material deflected from the
stream by a rotary member cannot pass to a rotary member
therebeneath.
Further, it will be appreciated that whilst the rotary
members 26, 27, 28 and 30 have been described as having round
;~ holes the invention is not restricted to the openings being
round and opening of othér shapes may be used. Further the
number of holes through each rotary member 26, 27, 28 and 30
may be more or less than the four described.
It will also be appreciated that, whilst with illustrated
example the mask 21 interrupts some 50% of the flowable
material centrifuged from the rotary members within the mask
21 there is perferably one rotary member externally of the mask
21 for each two rotary members within the mask 21. Further,
~; it will be appreciated that the rate of distribution of flow-
able material from the, or each, assembly of rotary members
may be increased by increasing the number of rotors on the
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shaft 24 and so arranging the openings through the rotors,
in the manner proposed by the present invention, that the stream
of flowable material is equally distributed to the rotary
members within the mask. Further, it will be appreciated
that more than one flowable material stream may be directed
towards the uppermost rotary disc and, when a plurality of
supply streams are provided, said streams are preferably
spaced about the~rotational axis for the assembly of rotors.
A substantial advantage gained by supplying a plurality
of rotary members with flowable material from a source
externally of the assembly of rotors is that the rotary
members may be arranged in close relationship, thus reducing
the height of the assembly of rotary members and the vertical
height of the mask.
Whilst the present invention has been described by way
of example with reference to specific examples it will be
appreciated that many modifications and variations will be
apparent to persons skilled in the art and such modifications
and variations as practice supplying flowable material to a
rotary member by deflecting part of a stream of flowable
; material to constitute the supply to the rotor whilst allowing
the undeflected stream to pass through the rotor must lie
within the scope of this invention.
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