Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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COATING OF PARTICULATE MATERIAL USING A CONICAL DISPERSION
APPARATUS
This invention is in the field of materials preparation, and
more particularly deals with a method and apparatus for the
application of wet or dry coatings to particulate material.
io
BACKGROUND
Many circumstances and commercial processes exist where it is
the desired result to apply a spray coating to particulate
material.
One such circumstance is the production of particulate animal
feed. It is in some cases desirable to apply a coating of
2o nutrients, vitamins or other ingredients to pelletized feed.
There are also circumstances in which such vitamins or other
ingredients are presently mixed with the remainder of the
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ingredients before pelletization, but certain ingredients may
be volatile in the pelleting process and as such it would be
desirable to come up with a method of application of such
ingredients in an even fashion to the outside of the pellets
after the durable ingredients are blended and pelleted.
SUI~iI~IRY OF THE INVENTION
It is the object of the present invention to provide an
improved method and apparatus for the spray coating of
particulate material. A conical dispersion element centrally
placed within a stream of flowing particulate material is
used, and the dispersed material is spray coated as it drops
off the bottom edge of the cone.
The apparatus of the present invention accomplishes this
object comprising substantially a raw material source from
2o which raw particulate material to be coated is formed into a
stream; a conical dispersion element, said conical dispersion
element having an apex and a bottom edge, said conical
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dispersion element being mounted with its apex below said
material source and substantially centred in the stream of raw
material; and a coating nozzle directed to apply a coating to
said raw material after it has been discharged off of the
bottom edge of said conical dispersion element.
It will be understood that cones of various shapes and sizes
could be used dependent upon the circumstances and insofar as
varying the shape or size or other dimension of the conical
1o dispersion element would not affect the overall operation of
the apparatus it will be understood that such variation and
attendant modifications as would be obvious to one skilled in
the art are contemplated within the scope of the present
invention.
Also, the apex of the cone could be either pointed or blunt -
that is to say that the dispersion element might be generally
conical in appearance with a domed apex or otherwise, so long
as the behaviour of particulate material passing thereover is
2o not adversely affected, and all such modifications are also
contemplated within the scope of the present invention.
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The coating nozzle might be mounted in one of many positions,
so long as it accomplishes the goal of spray coating the raw
particulate material as it drops off the bottom edge of the
conical dispersion element. It is particularly contemplated
that one location for the coating nozzle would be below the
conical dispersion element within the area defined by the
bottom edge of same. If a 360 degree spray pattern nozzle
were used, the one nozzle could spray all of the curtain of
particulate material created by the flowing of material off of
the bottom edge of the conical dispersion element. It is even
foreseeable that the coating nozzle might be mounted within
the conical dispersion element, with its discharge pointed
down out of the mouth defined by the outer edge of the conical
dispersion element.
The apparatus of the present invention could be mounted within
an application chamber to control the spray coating process
and the generation of waste or residue therefrom. Where an
application chamber was used, a coated material discharge
2o could be added to the bottom of the application chamber,
whereby coated material could be evacuated from the
application chamber.
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The apparatus of the present invention could be further
modified by adding a measuring apparatus to measure the flow
of raw material in the stream or onto said conical dispersion
element.
A regulating means or apparatus could also be added to
regulate the flow of coating through the coating nozzle to be
applied to the raw material.
1o In some embodiments of the apparatus, both the measuring
apparatus and the regulating apparatus could be used and
interconnected such that the application of coating to the raw
material would be controlled and regulated in accordance with
the amount of raw material streaming onto the apex of the
cone .
The apparatus might also include the addition of protrusions
to the surface of the conical dispersion element. The
protrusions might be a plurality of fins. The fins might be
2o arranged in a spiral pattern from the apex to the bottom edge
of the conical dispersion element. Any such protrusions which
were added to the surface of the conical dispersion element
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could be used to alter the flowing behaviour of the raw
material over the conical dispersion element and potentially
impart movement thereon upon dropping of the raw material from
the bottom edge of the conical dispersion element. A hopper
might be added below the conical dispersion element to receive
the coated material.
Also disclosed is a method of spray coating of particulate
material, said method comprising the steps of flowing a stream
of particulate material down over the apex of a conical
dispersion element, and spraying the coating to be applied
onto the raw material as it flows off of the bottom edge
thereof via one or more coating nozzles.
This method might be further amended by adding a step of
measuring the flow of raw material onto the conical dispersion
element, and regulating the amount of coating applied based
upon the flow or quantity of raw material in the stream.
2o If more than one coating was desired to be applied at the same
time, the coating materials could either be blending and
applied through the same nozzle, or alternatively more than
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one coating nozzle could be positioned to apply more than one
coating to the raw material at the same time.
Either wet or dry spray coatings could be applied to raw
material using the process of the present invention, with the
necessary attendant modifications to the type of coating
nozzles used.
The apparatus of the present invention could be used in the
1o practice of this process.
It will be understood that any type of particulate material
could be the raw source material used in the apparatus or
method of the present invention for coating and the
application of any wet or dry coating to any such material is
contemplated within the scope of the present invention. It
will be understood that the method and apparatus of the
present invention could be used in various applications other
than feed pellet coating, without departing from the scope and
2o intent of the claimed invention.
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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:
1o Figure 1 shows one embodiment of the apparatus of the
present invention;-
Figure 2 shows a second embodiment of the apparatus of
the present invention, including measurement and
regulating apparatus for the controlled application of
the coating to the raw material;
Figure 3 is a process flow diagram of one embodiment of
the process of the present invention;
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS:
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As outlined above, the present invention covers a method and
apparatus for the spray coating of particulate material, using
a conical dispersion apparatus to maximize the efficiency of
spray coating.
Figure 1 shows a first basic embodiment of the apparatus of
the present invention. The apparatus (1) shown includes an
application chamber (3) within which the spray coating of the
particulate material will take place. There is also shown a
io material source (2) from which raw particulate material (10)
to.be coated is formed into a stream (11).
In addition to the material source (2) , the next element of
the apparatus of the present invention is a conical dispersion
element (4). The conical dispersion element (4) has an apex
( 5 ) and a bottom edge ( 6 ) , with a surface extending thereabout
and therebetween. The conical dispersion element (4) is
mounted below the material source (2), and with the apex (5)
substantially centred in the stream (11) of raw material. As
2o such, raw material in the stream (11) passing over the apex
(5) of the conical dispersion element (4) will be separated
and will randomly flow down the surface of the conical
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dispersion element (4) about its outer edge. The spray
coating will be applied to the raw material (10) as it falls
off of the bottom edge (6) of the conical dispersion element
(4) .
Next is shown a coating nozzle (8), which is directed to apply
a coating (12) to the raw material (10) after the raw material
(10) has been discharged off of the bottom edge (6) of the
conical dispersion element (4). It will be understood that
1o the coating nozzle could be placed in various positions to
accomplish this goal and the placement of the nozzle in any
position in relation to the conical dispersion element (.4)
which accomplishes the objective of allowing for the
application of a spray coating to the raw material (10) as it
i5 falls off of the bottom edge (6) of the conical dispersion
element (4) is contemplated within the scope of the present
invention.
In this embodiment, the coating nozzle (8) is shown mounted
2o below the conical dispersion element (4), and within the area
defined by the extension of the bottom edge (6) of same. In
this fashion a single coating nozzle (8) with a 360 degree
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spray pattern, can effectively spray all of the raw material
(10) falling off of the bottom edge (6) of the conical
dispersion element (4).
Also shown in the application chamber (3) is a coated material
discharge (9). The coated material discharge (9) is used to
remove the spray coated material from the application chamber
(3) upon completion of the spraying. In this case, the coated
material discharge (9) is a hopper bottom. It will be
understood that various types of coated material discharges,
with or without mechanical assistance, could be used depending
upon the circumstances and the present invention is intended
to cover all such variations on the coated material discharge.
i5 In operation of the device (1) the stream (11) of raw material
passes over the apex (5) of the conical dispersion element
(4). As the material (10) drops off of the bottom edge (6) of
the conical dispersion element (4), in a sheet or curtain of
the approximate shape and diameter of the base of the conical
2o dispersion element (4), the coating nozzle (8) spray coats all
of this material as it passes the coating nozzle (8).
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Figure 2 shows another embodiment of the apparatus of the
present invention extending the concept further. Firstly, it
can be seen that there are a plurality of coating nozzles (8)
used in this embodiment. The coating nozzles (8) could all be
connected to the same coating source, such that the same
coating would be sprayed from each nozzle, or alternatively
different ones of the coating nozzles (8) could be connected
to different coating sources, such that various coatings could
be applied at the same time. It will be understood that each
to such variation is contemplated within the scope of the present
invention. Furthermore, while only four coating nozzles (8)
are shown in this embodiment, it will be understood that any
number of coating nozzles could be used without departing from
the scope of the claimed invention.
It is particularly contemplated that by changing the type of
coating nozzle (8) different apparatus could be built for the
application of wet or dry coatings to the material (10). It
will be understood that both wet and dry nozzles are
contemplated within the scope of the present invention.
Also shown in the apparatus of Figure 2 is a measuring
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apparatus (12), which would measure the flow of raw material
onto the apex (5). Any such measuring device (12) is
contemplated within the scope of the invention insofar as it
accomplishes the objective of measuring the flow of raw
s material (10) in the stream (11). One such measuring device
(12) might be a dry flow measuring device. Either flow or
actual volume measurements could be taken by the measuring
apparatus (12) and it will be understood that both types of
measuring apparatus, namely both those that detect flow
through the source ( 2 ) and into the stream ( 11 ) , or those that-
detect the actual volume of material (10) contained in the
stream (11) as it streams onto the apex (5), are contemplated
within the scope of the present invention.
i5 By measuring or detecting flow of raw material (10) onto the
apex (5), the overall operation of the apparatus could either
be monitored or controlled accordingly.
Additionally, a regulating apparatus (13) is connected to the
2o coating nozzle (8) in order to regulate the amount of coating
being applied to the raw material (10) based on the flow of
material (10) detected by the measuring apparatus (12). It
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will be understood that various conventional means of
measurement could be used as the measuring apparatus (12) to
quantify the volume of the stream (11). Various types of
regulators (13) could be used to control the amount of coating
being applied by the coating nozzles) (8). It will be
understood that any type of regulator or regulating control is
contemplated within the scope of the present invention as
well.
1o The measuring apparatus (12) and the regulating apparatus (13)
could be operatively connected for the automatic adjustment of
the regulating apparatus (13) based on the measurements
yielded by the measuring apparatus (12). Alternatively, it is
also foreseeable that in certain cases the measuring apparatus
(12) might be connected to some type of a display output or
gauge, and the operator of the apparatus could then manually
control the regulating apparatus (13). It will be understood
that both manual or automatic operation of the regulating
apparatus (13) based on the output from the measuring
2o apparatus (12) is contemplated within the scope of the present
invention.
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It is also particularly contemplated that where an automatic
control of the regulating apparatus (13) is desired, a
computer could be connected to the measuring apparatus (12)
and the regulating apparatus (13) and the computer adapted
such as to accept an input from the measuring apparatus (12)
and generate and output to the regulating apparatus (13). In
this case, the computer (14) is shown. The behaviour of the
apparatus could be adjusted by recalibrating the software in
the computer, where it was desired to, at various points,
to perform coating operations within different parameters within
the apparatus.
Also shown in the apparatus of Figure 2 is the addition of
protrusions (7) to the surface of the conical dispersion
element (4). The protrusions (7), in this case taking the
shape of fins, could take various shapes or profiles and might
be used in various ways to alter the flowing behaviour of the
raw material (10) over and off of the conical dispersion
element (4). It will be understood that any such protrusion
2o accomplishing this effect is contemplated within the scope of
the present invention_
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The protrusions (7) which are shown in Figure 2 are a
plurality of fins which are arranged in a spiral pattern
around the outer surface of the conical dispersion element
(4). Specifically, the spiral extends from the apex (5) to
points along the bottom edge (6). As such, as material (10)
is streamed over the apex (5), the fins (7) will result in the
imparting of a slight spiral motion upon various particles of
material (10) as they drop off the bottom edge (6) of the
cone. If there is some degree of spiral motion imparted upon
1o the particulate material (10) before it drops off of the
bottom edge (6) of the cone, a more complete spray coverage
might be accomplished as well as if the spiral movement
continues to any degree as the material (10) drops to the
bottom of the application chamber (3), the coated pellets or
particles might continue to blend themselves to some extent as
they exit from the coated material discharge hopper (9).
In addition to the specific apparatus of the present
invention, there is also disclosed a process for the spray
zo coating of particulate material using a conical dispersion
apparatus. This method comprises the steps of flowing a
stream of raw particulate material to be coated from a
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material source down over the apex of a conical dispersion
element and spraying the coating to be applied to the raw
material as the raw material flows off of the bottom edge of
the conical dispersion element. The conical dispersion
s apparatus allows for the random, but generally equal,
separation and dispersion of the particulate material to be
coated before the spray coating is applied.
The utility and precision of the process could be extended by
1o measuring the flow of the stream of raw material onto the
apex, and optionally, either automatically or by operator
control or input, adjusting the amount of coating being
sprayed and applied by the coating nozzle based upon the
measurement of flow over the apex.
Any embodiment of the apparatus of the present invention could
be used to practice this process.
Thus it can be seen that the invention accomplishes all of its
2o stated objectives. The foregoing is considered as
illustrative only of the principles of the invention.
Further, since numerous changes and modifications will readily
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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
s to are intended to fall within the scope of the claimed
invention.
