Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
IMPROVED DISTRIBUTION UNIFORMITY IN AIR SEEDERS
This disclosure relates to the field of agricultural air seeders and in
particular improving
the uniformity of product distribution to the furrow openers of air seeders.
BACKGROUND
Air seeders typically include an implement frame mounted on wheels, with a
plurality of
furrow openers mounted on the frame. The furrow openers can be moved from a
raised
non-operative position to a lowered operating position where the furrow
openers engage
the ground and create furrows. Agricultural products such as seed and various
types of
fertilizer are carried in separate tanks which can be mounted on the implement
frame or
on a cart towed along with the implement frame.
Metering devices dispense products from the tanks into one or more air streams
that carry
the products through a network of hoses and manifolds to the furrow openers
where same
are deposited in the furrows. In order to achieve a uniform application rate
of agricultural
products on the field, the rate of product flowing to each furrow opener
should be the
same.
In a typical air seeder a metering roller, auger, or the like dispenses
product from each
tank into an air stream. Typically a conduit connects the air stream to the
top of the
interior of the tank to pressurize the tank so that there is no pressure
differential between
the tank and the air stream which would put back pressure on the product as it
is being
metered into the air stream.
United States Patent Number 5,592,887 to Bourgault discloses a multi
compartment air
seeder where a single meter is used to distribute product from each tank into
one air
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stream. In this type of configuration the air stream typically carries the
product through a
primary hose to a primary manifold where the air stream and product entrained
therein is
divided and directed into multiple secondary hoses connected to the primary
outlet ports
of the primary manifold. In turn then each secondary hose connects into a
further
secondary manifold and the air stream is divided again into further final
hoses leading to
each furrow opener.
United States Patent Number 8,733,257 to the present inventor Beauj ot in
contrast
discloses a multi compartment air seeder where a plurality of meters is used
to distribute
product from each tank into a corresponding plurality of air streams each
flowing through
a primary hose. Each primary hose then delivers the air stream and entrained
product
through a downstream product distribution network that includes a manifold and
final
hoses connected to the manifold output ports that carry the divided air stream
and product
to each furrow opener. Each product distribution network delivers product to
furrow
openers grouped on a laterally distinct section of the implement frame, such
that the
meters can be selectively activated to turn supply to any section on and off
to reduce
overlap of prior seeded areas.
In both the Bourgault and Beaujot air seeder systems, a single fan provides an
initial air
stream. In Bourgault's system the meter dispenses all the product from a tank
into a
single primary hose carrying that initial air stream which carries all the
product tank to
the primary manifold where the air stream and product entrained therein is
divided. In
contrast in the Beaujot system the initial air stream is divided into a
plurality of separate
primary air streams, each carried in a separate primary hose, before it gets
to the meters
" -
and each meter dispenses product into a corresponding one of the primary hoses
for
delivery through the corresponding product distribution network to the furrow
openers.
In the Beaujot system, back pressure in each primary hose is developed by the
resistance
to flow of the downstream elements of the product distribution network, and
can vary
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significantly from one primary hose to the next. Depending on the particular
configuration, some manifolds may have more output ports than others, feeding
product
to more furrow openers. With fewer output ports and final hoses, the total
cross-sectional
area of the air path in the product distribution network will be comparatively
less and
back pressure will typically be greater in the product distribution network
where the
manifold has less output ports.
And even where the manifold in each product distribution network has the same
number
of output ports, the length of the primary hoses typically is much greater
where the
manifold is located on an outer end of the implement frame, and so increased
back
pressure is present in those product distribution networks with a longer
primary hose.
For this reason it is known make all the primary hoses the same length. The
lengths of
the final hoses from each manifold can also vary resulting in unequal back
pressure
between product distribution networks, and positioning of manifolds and furrow
opener
locations may make it difficult achieve equal hose lengths.
Similarly when product is turned off to one of the sections, the air stream
continues to
flow in the corresponding product distribution network but since the air
stream is
carrying no product, the back pressure in that "empty" product distribution
network is
significantly reduced, leading to cross flow of air through the meters.
Thus unequal back pressures are often present in the primary hoses at the
location where
the product is being metered from the tank into each primary hose. Since each
meter is
metering from the same tank an air path through the bottom portion of the tank
is present
from one meter to the next and air will cross flow from the primary hose with
a higher
pressure back through the corresponding meter to a meter dispensing product
into a
primary hose where the pressure is comparatively less. This cross flow of air
can disrupt
the flow of metered product such that the desired product flow rate and a
consequent
uniform application rate of agricultural products on the field is not
achieved.
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In addition to disrupting metered product flow this cross-flow of air through
the tank,
especially in very humid conditions, the wet air passing through agricultural
products like
fertilizer can cause the product to cake and obstruct the flow of product from
the tank to
the metering device.
Instead of providing a plurality of meters in each tank to supply a
corresponding plurality
of primary hoses United States Patent Number 7,690,440 to Dean et al. a single
continuous meter roller metering into a plurality of primary hoses spaced
along a length
,
of the meter roller such that a section of the meter roller feeds each primary
hose. A gate
mechanism selectively shuts off flow of product from the tank to each section
of the
meter roller. Cross flow of air along the meter roller due to uneven back
pressure in the
primary hoses is problematic with this system as well.
SUMMARY OF THE INVENTION
The present disclosure provides a system for improving the uniformity of
agricultural
product distribution in air seeders that overcomes problems in the prior art.
In a first embodiment the present disclosure provides a product metering and
distribution
system for an air seeder. The system comprises a fan operative to direct a fan
air stream
at a fan pressure into first and second product distribution networks such
that a first air
stream flows through the first product distribution network and a second air
stream flows
through the second product distribution network, and a product tank and a
pressure
equalizing conduit connecting an upper portion of the product tank to receive
pressurized
air from the fan. A metering assembly is operative to dispense first and
second product
streams of agricultural product from the product tank through corresponding
first and
second meter dispensing ports into corresponding first and second feed ports
in the
corresponding first and second product distribution networks. First and second
bypass air
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channels connect the corresponding first and second feed ports to the tank
such that when
a first stream pressure at the first feed port is greater than a second stream
pressure at the
second feed port, air passes from the first feed port through the first bypass
air channel
and through the first meter dispensing port into the tank and then out of the
tank through
the second bypass air channel and the second meter dispensing port to the
second feed
port.
In a second embodiment the present disclosure provides a product metering and
distribution system for an air seeder. The system comprises a fan operative to
direct a fan
air stream at a fan pressure into first and second primary hoses such that a
first air stream
:= = ==
flows through the first primary hose to a first product distribution network
and a second
air stream flows through the second primary hose to a second product
distribution
network, and a product tank and a pressure equalizing conduit connecting an
upper
portion of the product tank to receive pressurized air from the fan. A
metering assembly
is operative to dispense first and second product streams of agricultural
product from the
product tank through corresponding first and second meter dispensing ports
into
corresponding first and second feed ports in the corresponding first and
second primary
hoses. A first restrictor assembly on the first primary hose downstream from
the first
feed port is operative when activated to increase a resistance to air flow
through the first
primary hose downstream from the first feed port.
In a third embodiment the present disclosure provides a product metering and
distribution
system for an air seeder. The system comprises a fan operative to direct a fan
air stream
' at a fan pressure into first and second primary hoses such that a first
air stream flows
through the first primary hose to a first product distribution network and a
second air
stream flows through the second primary hose to a second product distribution
network,
and a product tank and a pressure equalizing conduit connecting an upper
portion of the
product tank to receive pressurized air from the fan. A metering assembly is
operative to
dispense first and second product streams of agricultural product from the
product tank
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through corresponding first and second meter dispensing ports into
corresponding first
and second feed ports in the corresponding first and second primary hoses.
First and
second product flow sensors are operative to measure a flow rate of
agricultural product
in the corresponding first and second primary hoses downstream from the
corresponding
first and second feed ports, and a meter control is operative to receive flow
rate
information from the first and second product flow sensors and to adjust the
metering
system to dispense agricultural product in the corresponding first and second
product
- streams at corresponding first and second target rates.
The product metering and distribution systems disclosed herein for use on an
air seeder
provide increased uniformity of product application rates across the width of
an air
seeder. In systems where the cross flow of air between from one metering
device through
the tank to another metering device is reduced, the caking of products in the
tank, such as
fertilizer, due to the flow of humid air is reduced.
DESCRIPTION OF THE DRAWINGS
While the invention is claimed in the concluding portions hereof, preferred
embodiments
are provided in the accompanying detailed description which may be best
understood in
conjunction with the accompanying diagrams where like parts in each of the
several
diagrams are labeled with like numbers, and where:
Fig. 1 is a schematic top view of an embodiment of the product metering and
distribution system of the present disclosure mounted on an air seeder;
Fig. 2 is a schematic side view of the embodiment of Fig. 1;
Fig. 3 is a schematic sectional view along lines 3-3 in Fig. 1;
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Fig. 4 is a schematic sectional view of the first metering device shown in
Fig. 3;
Fig. 5 is a schematic sectional view of the second metering device shown in
Fig. 3;
Fig. 6 is a schematic top view of an alternate embodiment of the product
metering and
distribution system of the present disclosure mounted on an air seeder with
the tanks
removed for clearer illustration;
Fig. 7 is a schematic sectional end view of the squeezing restrictor assembly
of the
embodiment of Fig. 6, with the restrictor assembly in a non-restricting
position;
Fig. 8 is a schematic sectional end view of the squeezing restrictor assembly
of the
embodiment of Fig. 6, with the restrictor assembly in a restricting position;
Fig. 9 is a sectional end view of an alternate restrictor assembly, with the
restricting
position shown in phantom lines;
Fig. 10 is a sectional side view of the alternate restrictor assembly of Fig.
9, with the
restricting position shown in phantom lines;
Fig. 11 is a sectional side view of a further alternate restrictor assembly,
with the
restricting position shown in phantom lines;
Fig. 12 is a schematic sectional view of a metering device showing an air
sensing
apparatus comprising either an air pressure sensor or an air flow sensor;
Fig. 13 is a schematic sectional front view showing the air flow sensor
mounted in a
perforated enclosure in the tank between two metering devices to sense air
flowing
from one metering device to the next;
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Fig. 14 is a schematic top view of a further alternate embodiment of the
product
metering and distribution system of the present disclosure mounted on an air
seeder
with the tanks removed for clearer illustration.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Figs. 1 ¨ 3 schematically illustrate an embodiment of a product metering and
distribution
system 1 of the present disclosure for use on an air seeder 3. The system 1
comprises a
fan 5 operative to direct a fan air stream at a fan pressure into first and
second product
distribution networks 7A, 7B such that a first air stream 9A flows through the
first
product distribution network 7A and a second air stream 9B flows through the
second
product distribution network 7B. A product tank 11 contains agricultural
products for
application to a field and a cover 13 is operative to seal a fill opening of
the product tank
11 such that the product tank can be pressurized.
Figs. 1 ¨ 3 schematically illustrates a typical air seeder with a three
product tanks 11 and
three distribution networks 7. As is typical, each distribution network 7
comprises a
primary hose 15 connected to receive an air stream 9 from the fan 5 and then
extending
under the tanks 11 to receive agricultural products from one or more selected
tanks 11
and then carrying the air stream and entrained agricultural products to a
manifold 17.
Secondary hoses 19 connect each manifold 17 to the furrow openers 21 of the
air seeder
3. The description here refers only to one of the product tanks 11 and only to
first and
second distribution networks 7A, 7B however those skilled in the art will
recognize that
the system 1 of the present disclosure may be replicated for each product tank
11 and any
plurality of distribution networks 7.
A metering assembly 23 comprises first and second metering devices 25A, 25B
operative
to dispense first and second product streams 27A, 27B of agricultural product
from the
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product tank 11 through corresponding first and second meter dispensing ports
29A, 29B
into corresponding first and second feed ports 31A, 31B in the corresponding
first and
second primary hoses 15A, 15B of the product distribution networks 7A, 7B as
schematically illustrated in Figs. 4 and 5. The first metering device 25A is
shown in Fig.
4 and the second metering device 25B, which as seen in Fig. 3 is located under
the tank
11 beside the first metering device 25A, is shown in Fig. 5.
In the illustrated system 1, where a first stream air pressure PA of the air
stream 9A in the
first primary hose 15A at the first feed port 31A is greater than a second
stream air
pressure PB of the air stream 9B in the second primary hose 15B at the second
feed port
31B, a cross flow air stream 33 will develop flowing from the primary hose 15A
through
the first meter dispensing port 29A into the tank 11 and through the tank 11
and out the
second meter dispensing port 29B to the second primary hose 15B. This cross
flow air
stream 33 flowing into the first meter dispensing port 29A generates
resistance to the
flow of product out of the first meter dispensing port 29A and somewhat
reduces the
amount of product in the first product stream 27A. Similarly the flow of air
out of the
second meter dispensing port 29B assists the flow of product out of the second
meter
dispensing port 29B and somewhat increases the amount of product in the second
product
stream 27B. Thus the uniformity of product application is adversely affected.
The present system 1 however provides first and second bypass air channels
35A, 35B
that provide an additional path connecting the corresponding first and second
feed ports
31A, 31B to the tank 11 such that a portion 33' of the cross flow air stream
33 passes
from the first meter port 31A through the first bypass air channel 35A and
another
portion 33" of the cross flow air stream 33 passes through the first meter
dispensing port
29A into the tank 11 and then out of the tank 11 through the second bypass air
channel
35B and the second meter dispensing port 29B to the second feed port 31B. With
the
additional air path provided by the bypass channels 35, the flow into the
first meter
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dispensing port 29A and out the second meter dispensing port 29B is much
reduced, and
so also then the disruption of product flow is reduced as well.
The illustrated metering devices 25 comprise a feed wheel 37 rotatable about a
substantially horizontal rotational axis RA in direction R and mounted in a
housing 39
attached to a bottom wall 41 of the product tank 11 and connected to the
corresponding
feed port 31. The feed wheel 37 is mounted with an inside portion 37' of an
outer surface
thereof exposed to agricultural product in the product tank 11 and an outside
portion 37"
of the outer surface thereof in the housing 39. In each metering device 25 the
meter
dispensing port 29 is adjacent to a bottom of the feed wheel 37 and the bypass
air channel
35 is above the feed wheel 37.
The first and second bypass air channels 35A, 35B are provided by
corresponding first
and second openings in the bottom wall 41 of the product tank 11 inside the
housing 39
of the metering devices 25. The openings are oriented generally horizontally
so that
product in the tank 11 will not flow out through the bypass air channels 35.
It is
contemplated that the bypass air channels 35 will be larger than the meter
dispensing port
29 providing a path of lesser resistance such that the portion 33' of the
cross flow air
stream 33 passing through the bypass air channels 35 will be greater than the
portion 33"
of the cross flow air stream 33 passing through the meter dispensing ports 29.
, In addition the portion 33' of the cross flow air stream 33 passes
from the first bypass air
channel 35A to the second bypass air channel 35B along a path through the tank
11 above
the feed wheels 37 while the portion 33" of the cross flow air stream 33
passes from the
first meter dispensing port 29A to the meter dispensing port 29B along a path
through the
tank 11 somewhat below the path of portion 33', such that humid air is spread
over a
greater portion of the product in the tank 11 and caking of product such as
fertilizer is
reduced.
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Fig. 6 schematically illustrates a product metering and distribution system
101 for use on
the air seeder shown in Figs. 1 ¨ 3 to reduce the cross flow of air from one
metering
device 25 to another. A metering assembly 23, for example such as including
metering
devices 25 such as shown in Figs. 4 and 5, is operative to dispense first and
second
product streams of agricultural product from the product tank 11 through
corresponding
first and second meter dispensing ports into corresponding first and second
feed ports
31A, 31B in the corresponding first and second primary hoses 15A, 15B.
The system 101 comprises a first restrictor assembly 143A on the first primary
hose 15A
õ.. ,
downstream from the first feed port 31A. The first restrictor assembly 143A is
operative
when activated to increase a resistance to air flow through the first primary
hose 15A.
With this system 101, when second air stream pressure of the second air stream
9B in the
second primary hose 15B at the second feed port 31B is greater than the first
air stream
pressure of the first air stream 9A in the first primary hose 15A at the first
feed port 31B,
the first restrictor assembly 143A is activated to increase the resistance to
air flow
through the first primary hose 15A downstream from the first feed port 31A.
This
increased resistance causes the first air stream pressure of the first air
stream 9A in the
first primary hose 15A at the first feed port 31B to rise.
In an air seeder with an overlap control 145, the first metering device 25A
can be
controlled to stop dispensing the first product stream into the first air
stream 9A while the
second metering device 25B continues to dispense the second product stream
into the
second air stream 9B. While the first air stream 9A continues to flow, it is
not pushing
any product through the first distribution network 7A downstream from the
first feed port
31A and so the resistance to air flow through the first primary hose 15A is
significantly
reduced compared to the pressure of the second air stream 9B which continues
to push
product through the second distribution network 7B. This unequal air pressure
at the first
and second feed ports 31A, 31B causes a cross flow air stream as described
above.
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The overlap control 145 can be configured to control the metering assembly 23
to stop
dispensing the first product stream and also to simultaneously activate the
first restrictor
assembly 143A to increase the resistance to air flow through the first primary
hose 9A to
a level where the first air pressure at the first feed port 31A is
substantially equal to the
second air pressure at the second feed port 31B. Where the product application
rate is
substantially constant, the pressure differential between the first and second
feed ports
31A, 31B will be substantially the same each time product flow is stopped in
the first
primary hose 15A, and the level of restriction can be determined by trial and
error
measuring air pressure or the air flow that results from unequal air pressures
at the feed
ports 31A, 31B. A restrictor control 149 is operative to activate the first
restrictor
assembly 143A when the first air pressure is less than the second air pressure
and to
adjust the first restrictor assembly 143 to achieve a first air pressure that
is substantially
equal to the second air pressure.
A second restrictor assembly 143B is present on the second primary hose 15B
downstream from the second feed port 31B, and is operative when activated to
increase a
resistance to air flow through the second primary hose 15B, and the restrictor
control 149
is operative to activate the second restrictor assembly 143B when the second
air pressure
at the second feed port 31B is less than the first air pressure at the first
feed port 31A and
to adjust the second restrictor assembly 143B to achieve a second air pressure
that is
substantially equal to the first air pressure.
An air sensor apparatus 147 is operative to sense that first and second air
pressures at the
corresponding first and second feed ports 31A, 31B are unequal, and the
restrictor control
149 is operative to activate a selected one of the first and second restrictor
assemblies
143A, 143B when the first and second air pressures are unequal and to adjust
the selected
restrictor assembly 143 to achieve substantially equality of the first and
second air
pressures.
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Figs. 6 and 12 schematically illustrate the air sensor apparatus 147 that
includes air
pressure sensors 147A, 147B. The air sensor apparatus 147 senses that the
first and
second air pressures at the corresponding first and second feed ports 31A, 31B
are
unequal by directly sensing the first and second air pressures.
Fig. 12 also schematically illustrates the air sensor apparatus 147' provided
by an air flow
sensor. The air sensor apparatus 147' senses that the first and second air
pressures at the
õ. corresponding first and second feed ports 31A, 31B are unequal by
sensing air flowing in
a cross flow air stream 33 from one of the first and second feed ports 31A,
31B toward
the other of the first and second feed ports 31A, 31B.
Such an air sensor apparatus 147' is also illustrated in Figs. 4 and 5 where
first and
second bypass air channels 35A, 35B connect the corresponding first and second
feed
ports 31A, 31B to the tank 11 such that when the first air pressure PA at the
first feed port
31A is greater than the second air pressure PB at the second feed port 31B,
air passes
from the first feed port through the first bypass air channel 35A and through
the first
meter dispensing port 29A into the tank 11 and then out of the tank 11 through
the second
bypass air channel 35B and the second meter dispensing port 29B to the second
feed port
31B. Here the flap 165 of the air sensor apparatus 147' is pivotally attached
to an upper
wall of the housing 39 where same is located to sense the flow of air through
the first
bypass air channel 35A. This location is well away from the product streams 27
which
can interfere with the operation of the flap 165. This location also allows
the flap 165 to
hang down vertically such that a slight air flow will cause the flap 165 to
move indicating
that air is flowing and the pressures at the feed ports are not equal.
In the air sensor apparatus 147' shown in Fig. 12 air flow is sensed by a flap
165 pivotally
attached to an inner surface of a wall of the housing 39. Fig. 13
schematically illustrates
an alternate air sensor apparatus where the cross flow air stream 33 is sensed
by
positioning the flap 165 pivotally attached inside a perforated enclosure 167
located
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inside the tank 11 between the metering devices 25A, 25B. The perforations 169
allow
air to flow through the enclosure while keeping the product in the tank 11
out. This
configuration also allows the flap 165 to hang down vertically such that a
slight air flow
will cause the flap 165 to move indicating that air is flowing and the
pressures at the feed
ports are not equal.
To reduce response times, the overlap control 145 can be connected to the
restrictor
control 149 and configured such that when the product flow to one of the feed
ports 31 is
- stopped the restrictor control 149 begins to activate the corresponding
restrictor assembly
143, and then receives air pressure or air flow information to finalize the
degree of
restriction required to balance the air pressures.
In the system 101 of Fig. 6 the restrictor assemblies 143 each comprise a
resilient section
15R in the primary hose 15 and a squeezing apparatus 151 operative when
activated to
squeeze the resilient section 15R such that a cross-sectional area of the
first resilient
section 15R is reduced, as schematically illustrated in Fig. 7 where the
restrictor
assembly is in a non-restricting position and in Fig. 8 where the restrictor
assembly is in a
restricting position. The illustrated squeezing apparatus 151 comprises an
actuator 153
on one side of the resilient section 15R and a blocking plate 155 on the
other.
Figs. 9 and 10 schematically illustrate an alternate restrictor assembly 143'
comprising an
obstruction element 157 inside the primary hose 15, and an element actuator
159
operative to manipulate the obstruction element 157 to selectively increase
and decrease a
resistance to air flow through the primary hose 15. The restrictor assembly
143' for
example illustrates the obstruction element 157 as a balloon inside the
primary hose 15
and the actuator is a source of pressurized fluid operative to increase or
decrease a size of
the balloon to correspondingly increase and decrease a resistance to air flow
through the
primary hose 15.
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Fig. 11 schematically illustrates an alternate obstruction element 157'
provided by a flap
pivotally attached inside the primary hose 15 and an actuator 159' operative
to move the
flap down and up with respect to the inner surface of the primary hose to
correspondingly
increase and decrease a resistance to air flow through the primary hose 15.
Fig. 14 schematically illustrates a product metering and distribution system
201 for use
on the air seeder shown in Figs. 1 ¨ 3 to reduce the effects of the cross flow
of air from
one metering device 25 to another. A metering assembly 23, for example such as
" including metering devices 25 such as shown in Figs. 4 and 5, is operative
to dispense
first and second product streams of agricultural product from the product tank
11 through
corresponding first and second meter dispensing ports into corresponding first
and second
feed ports 31A, 31B in the corresponding first and second primary hoses 15A,
15B.
The system 201 comprises first and second product flow sensors 261A, 261B
operative to
measure a flow rate of agricultural product in the corresponding first and
second primary
hoses 15A, 15B downstream from the corresponding first and second feed ports
31A,
31B. A meter control 263 is operative to receive flow rate information from
the product
flow sensors 261 and to adjust the metering system 23 to dispense agricultural
product in
the corresponding first and second product streams at corresponding first and
second
target rates.
, Product flow sensors are available that provide an accurate reading of
product flow. The
product flow meter manufactured by Digitroll Kft. of Budapest, Hungary is
operative to
sense particle flow in a one inch diameter hose such as the secondary hoses 19
of a
typical air seeder. By mounting a flow sensor 261' on each secondary hose 19,
a sum of
product flow in all hoses 19 connected to manifold 17A determined by sensors
261A' will
give the product flow present in primary hose 15A. Similar sums can be
determined by
sensors 261B', 261C' with respect to manifolds 17B, 17C which will give
product flows
in primary hoses 15B, 15C.
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As illustrated in Figs. 4 and 5 the metering assembly 23 comprises first and
second
metering devices 25A, 25B with corresponding first and second rotating
metering wheels
37 that are operative to dispense the first and second product streams 27A,
27B of
agricultural product from the product tank 11. The metering control 263 is
operative to
adjust a rotational speed of the first and second metering wheels 37A, 37B to
dispense
agricultural product in the corresponding first and second product streams
27A, 27B at
the corresponding first and second target rates.
In a typical air seeder configuration the first distribution network 7A
carries the
agricultural product to a plurality of first furrow openers and the second
distribution
network 7B carries the agricultural product to a plurality of second furrow
openers. In
some air seeder configurations the number of furrow openers supplied by the
first and
second distribution networks 7A, 7B is the same, and in such a configuration
the first
target rate is equal to the second target rate. In other air seeder
configurations the number
of furrow openers supplied by the first and second distribution networks 7A,
7B is not the
same in all cases. In such a configuration where the number of first furrow
openers
supplied by the first distribution network 7A is greater than the number of
second furrow
openers supplied by the second distribution network 7B the first target rate
is larger than
the second target rate.
In the system 201 illustrated in Fig. 14, a third distribution network 7C is
illustrated
supplied in the same manner by the metering system 23 and monitored by a
product flow
sensor 261C. The manifold 17A in the first distribution network 7A and the
manifold 7C
in the third distribution network 7C each have six output ports each connected
to a
secondary hose 19 to supply a furrow opener 21, while the manifold 17B in the
second
distribution network 7B has only four output ports each connected to a
secondary hose
19. Thus the first and third distribution networks 7A, 7C supply the same
number of
furrow openers 21 and the target rate dispensed by the metering system into
each will be
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the same, while the second distribution network 7B supplies only 2/3 of the
number of
furrow openers supplied by the first and third distribution networks 7A, 7C
and so the
target rate dispensed by the metering system into the second distribution
network 7B will
be only 2/3 of the target rate for the first and third distribution networks
7A, 7C.
With system 201, the cross flow of air is not affected, however the effects of
the cross
flow on uniformity of application rates of agricultural products is
substantially
eliminated.
The product metering and distribution systems disclosed herein for use on an
air seeder
provide increased uniformity of product application rates across the width of
an air
seeder. In systems where the cross flow of air between from one metering
device 25
through the tank 11 to another metering device 25 is reduced, the caking of
products in
the tank 11, such as fertilizer, due to the flow of humid air is reduced.
The foregoing is considered as illustrative only of the principles of the
invention.
Further, since numerous changes and modifications will readily occur to those
skilled in
the art, it is not desired to limit the invention to the exact construction
and operation
shown and described, and accordingly, all such suitable changes or
modifications in
structure or operation which may be resorted to are intended to fall within
the scope of
' the claimed invention.
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