Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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INTAKE NOZZLE FOR A VACUUM CONVEYOR
This invention is in the field of pneumatic or vacuum conveyors such as are
commonly
used to convey granular material, and in particular an intake nozzle for such
machines.
BACKGROUND
Machines for conveying particulate or granular material using a vacuum are
well known,
for example for use in conveying grain. These machines allow pickup of
granular
material with a flexible hose that allows considerable freedom of movement. A
fan or air
pump is used to establish a flow of air from the intake end of the hose
through the
machine to a discharge. An intake nozzle at the end of the hose is placed in
the granular
material, and the air being sucked into the intake end carries picks up
granular material
and establishes a stream of mixed air and granular material that is carried
through the
hose. Typically the hose is in turn attached to a rigid tube, with the tube
and hose
forming an intake conduit between the vacuum conveyor and the intake nozzle.
Sections
of tube are added or removed, depending on the distance between the vacuum
conveyor
and the granular material.
When the intake end of the nozzle is placed into a pile of granular material,
the flow of
air is substantially blocked, and so a vent is provided on the intake nozzle
so that air can
enter the nozzle and maintain the flow of granular material. Such vents
typically
comprise one or more slots cut into the wall of the nozzle, although numerous
variants
are known. Typically a baffle is also provided to vary the area of the vent
that is open,
and so allow an operator to regulate the flow of air in through the vents in
accordance
with the particular material being conveyed, the length of the intake conduit
between the
vacuum conveyor and the intake nozzle, and other like operating conditions.
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SIJNI1VIARY OF THE INVENTION
It is an object of the present invention to provide an intake nozzle for
vacuum particulate
conveyors that overcomes problems in the prior art. It is a further object of
the present
invention to provide such an intake nozzle that includes a ramp portion
extending upward
and downstream from the intake conduit or nozzle wall. Advantageously, air
vents are
provided in the intake nozzle in conjunction with the ramps.
In a first embodiment the invention provides an intake conduit apparatus
comprising an
intake conduit adapted at a downstream output end thereof for connection to an
intake of
a vacuum conveyor, and adapted at an upstream input end thereof to facilitate
entry of
granular material. At least one ramp slopes inward and downstream from a
portion of an
interior of a wall of the intake conduit, and there is a vent hole through the
wall of the
intake conduit adjacent to a downstream end of the at least one ramp such that
air enters
the intake conduit adjacent to the downstream end of the at least one ramp.
In a second embodiment the invention provides an intake nozzle apparatus
adapted for
attachment at a down stream output end thereof to an input end of an intake
conduit of a
vacuum conveyor. The apparatus comprises a plurality of ramps arranged at
intervals on
the interior of a wall of the intake nozzle, each ramp sloping inward and
downstream
from a portion of an interior of the wall of the intake nozzle. There is a
vent hole through
the wall of the intake nozzle adjacent to a downstream end of at least one
ramp such that
air enters the intake nozzle adjacent to the downstream end of the at least
one ramp.
When conveying granular material from a storage bin with a vacuum conveyor
substantial portions of the intake conduit will typically be oriented
generally horizontally.
Until the bin is drained down somewhat, the intake nozzle will as well be
oriented
generally horizontally as well. In such a horizontal position the granular
material tends to
enter the bottom of the nozzle and remains there while traveling through the
intake
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conduit, held down by gravity. There is thus frictional resistance between the
granular
material and the walls of the intake conduit, and as well the speed of the air
stream is less
near the sides of the intake conduit.
Capacity is improved with the intake nozzle of the invention by moving the
granular
material toward the middle of the intake conduit where it can better mix with
the air
stream. Ramps are provided at intervals along the intake nozzle sloping inward
and
downstream from the wall of the nozzle. It may also be advantageous,
especially where
the intake conduit is lengthy, to install such ramps at intervals along the
entire conduit if
desired. For convenience, so that the sections do not have to be oriented so
that the ramp
is on the "bottom", ramps can be placed entirely around the interior of the
intake conduit
or nozzle. This has the further advantage of moving granular material from all
edges of
the conduit toward the center where the air velocity is greater.
In an intake nozzle, the centralizing action of the ramp can be accentuated by
providing a
vent hole in conjunction with the ramp so that the air comes into the nozzle
under the
ramp. The incoming air helps to move the granular material toward the center
of the
nozzle as the granular material comes off the downstream end of the ramp and
is met by
the air entering the nozzle through the vent.
Conveniently the ramps are provided by making a cut through a portion of the
wall of the
intake nozzle, leaving the cut portion attached to the wall at an upstream end
thereof.
The cut portion of the wall is pushed inwards to form a ramp sloping inward
and
downstream from the wall, leaving a hole in the wall. In this way the air
vents that are
required in all nozzles for allowing air to enter the nozzle are economically
provided at
the same time as the ramps are provided.
In one embodiment a cut is made in the wall perpendicular to the axis, and
then and then
is pushed in to form a rounded ramp that is closed on the sides such that the
air entering
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the vent hole enters in a direction corresponding to the downstream direction
of the ramp,
such that turbulence is reduced.
A plurality of such cuts are made to provide ramps and vent holes around the
nozzle wall.
A baffle can be added to open or close the vent holes as required.
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 perspective view an intake conduit of the invention
attached
to a vacuum conveyor;
Fig. 2 is a perspective view of the intake nozzle of Fig. 1;
Fig. 3 is a schematic cross-sectional side view of the intake nozzle of Fig.
1;
Fig. 4 is a schematic cross-sectional side view of an alternate embodiment of
the
intake nozzle of the invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS:
Fig. 1 illustrates an intake conduit 2 of the invention adapted at a
downstream output end
4 thereof for connection to an intake 6 of a vacuum conveyor 8. 1'he intake
conduit 2 is
adapted at an opposite upstream input end 10 to facilitate entry of granular
material to be
moved by an air stream from the input end 10 to the vacuum conveyor 8, and
thus
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through the output of the vacuum conveyor 8 as is well known in the art. The
typical
intake conduit comprises a section of rigid tubing attached to a flexible hose
to allow the
input end 10 to be maneuvered. In the illustrated embodiment the intake
conduit 2
further comprises a cylindrical intake nozzle 12 attached at the upstream
input end 10, as
further illustrated in Fig. 2.
Fig. 3 schematically illustrates the air stream created by the vacuum conveyor
flowing
through the intake nozzle 12 in the direction A carrying granular material 14
through the
intake nozzle 12. Typically the intake nozzle 12 will be oriented
substantially
horizontally as illustrated in Fig. 3 when loading granular material 14 from a
full bin.
Due to gravity the granular material 14 tends to fall toward the bottom of the
intake
nozzle 12 and remain there while traveling through the intake conduit.
In the present invention ramps 16 are arranged at intervals along the intake
nozzle 12.
The ramps 16 slope inward and downstream from a portion of the interior of the
wall 18
of the nozzle 12. A vent hole 18 is provided through the wall 20 of the intake
nozzle 12
adjacent to the downstream end of the ramp 16 such that air enters the intake
nozzle 12
adjacent to the downstream end of the ramp 16.
In the illustrated embodiment of Figs. 1 - 3 the ramps 16 conveniently
comprise a
partially cut out portion of the wall 20 of the intake nozzle 12. The cut out
portion is left
attached to the wall 20 at an upstream end thereof and is pushed inwards to
form the
ramp 16.
While the cut in the wall 20 to form the ramp 16 may be other shapes as well,
in the
illustrated embodiment, the cut is made substantially perpendicular to the
axis of the
intake nozzle 12, and then the portion of the wall 20 that is upstream from
the cut is
pushed in with rounded or cylindrical tool to form a curved ramp 16 and vent
hole 18.
Thus the partially cut out and pushed in portion of the wall 20 remains
attached to the
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wall 20 on sides thereof such that the vent hole 18 is oriented substantially
in a plane P
that extends across the intake nozzle 12, as illustrated. The plane P is
oriented at a small
angle off perpendicular with respect to the axis if the intake nozzle 12 due
to the
geometry of the ramp 16.
A plurality of such cuts are made to provide ramps 16 and vent holes 18 around
the
intake nozzle 12, as illustrated in Fig. 2. As illustrated in Fig. 3, the
granular material 14
moving along the bottom of the intake nozzle 12 is directed toward the center
of the
nozzle 12 by the ramps 16. The granular material 14 thus moves off the bottom
of the
nozzle 12 toward the middle thereof where it can better mix with the air
stream. Since
the ramps 16 are arranged around the intake nozzle 12, any granular material
14 moving
along the wall 20 of the nozzle 12 is directed toward the center.
This centralizing action of the ramps 16 is accentuated by providing the vent
holes 18 in
conjunction with the ramps 16 so that the air comes into the nozzle 12 under
the ramps
16. The incoming air helps to move the granular material 14 toward the center
of the
intake nozzle 12 as the granular material 14 comes off the downstream end of
the ramps
16 and improves mixing of the granular material and the air. In the
illustrated
embodiment of Figs. 1 - 3 the sloped and curved configuration of the ramp 16
and the
orientation of the vent holes 18 generally across the intake nozzle 12 also
directs air
entering through the vent holes 18 smoothly into the air stream.
The illustrated manner of making the ramps 16 and vent holes 18 by cutting and
pushing
a portion of the wall 20 toward the center of the nozzle 12 is convenient and
economical,
and also orients the vent hole 18 and ramp 16 to advantage. The air enters
intake nozzle
12 traveling generally smoothly in the downstream direction A under the
granular
material 14 coming off the downstream end of the ramp 16 such that the
granular
material I4 is prevented from falling to the bottom of the intake nozzle 12.
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A baffle 22 can be added to open or close the vent holes 18 to adjust the
amount of air
entering for different conditions. In Figs. 1 and 2 the baffle 22 comprises a
sleeve 24
movably mounted around an outer perimeter of the intake nozzle 12 such that
the sleeve
24 can slide or rotate with respect to the intake nozzle 12. The sleeve 24
defines a
plurality of sleeve apertures 2b arranged such that when the sleeve 24 is
moved to an
open position, as illustrated in Fig. 2, the sleeve apertures 24 are
substantially aligned
with corresponding vent holes 18. It can be seen then that when the sleeve 24
is moved
to a closed position the corresponding vent holes 18 are covered by the sleeve
24, and
when the sleeve 24 is moved to an intermediate position between the open and
closed
positions the corresponding vent holes 18 are partially covered.
Fig. 4 schematically illustrates an alternate embodiment comprising a ramp 116
that is
formed by a collar around the inside of the intake nozzle 112. Vent holes 118
are
punched through the nozzle wall 120 just at the downstream end of the ramp
116. Fig. 4
also illustrates an embodiment wherein the baffle 122 comprises a gate 124
movably
mounted on the intake nozzle 112 by a hinge, slide or the like such that when
moved to a
closed position the gate substantially covers the vent hole 118, and when the
gate 124 is
moved to an open position, as illustrated in Fig. 4, the vent hole 118 is
substantially
uncovered.
It may also be advantageous, especially where the intake conduit is lengthy,
to install
ramps at intervals along the entire intake conduit.
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.
