Title: Split-pan for panning apparatus
Abstract: A split-pan for a panning apparatus, a panning apparatus incorporating a split-pan, and a method of coating two distinct masses of centers simultaneously with the split-pan are described. The split-pan is formed as a hollow drum, having first and second ends, an interior volume, and at least one partition, positioned between the first and second ends. The partition divides the interior volume into a plurality of coating vessels that allow the simultaneous coating of a plurality of masses of centers in the respective coating vessels.
Patent Number: 6,960,361 Issued on 11/01/2005 to Chisholm, et al.
| Inventors:
|
Chisholm; Keith A. (Chattanooga, TN);
Ricketts; William R. (Cleveland, TN)
|
| Assignee:
|
Mars Incorporated (McLean, VA)
|
| Appl. No.:
|
308609 |
| Filed:
|
December 2, 2002 |
| Current U.S. Class: |
426/289; 427/2.14; 427/242; 118/19; 118/303; 118/418; 366/235 |
| Intern'l Class: |
A23G 001/04 |
| Field of Search: |
366/130,235,220
118/17,303,418
427/214,242
426/289
|
References Cited [Referenced By]
U.S. Patent Documents
| 913399 | Feb., 1909 | Kilpatrick.
| |
| 1655144 | Jan., 1928 | Hallgarth et al.
| |
| 2652805 | Sep., 1953 | D'Angelo.
| |
| 3357398 | Dec., 1967 | Gross.
| |
| 3936534 | Feb., 1976 | Schallis.
| |
| 4245580 | Jan., 1981 | Okawara.
| |
| 4676187 | Jun., 1987 | Grabowski.
| |
| 5395449 | Mar., 1995 | Quadir et al.
| |
| 5495418 | Feb., 1996 | Latini et al.
| |
| 5845992 | Dec., 1998 | MacKelvie.
| |
| 6142095 | Nov., 2000 | Long.
| |
Primary Examiner: Edwards; Laura
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto
Claims
1. A method of coating at least two separate masses of centers simultaneously
in a single coating apparatus, the method comprising the steps of:
providing the coating apparatus, which comprises a coating pan including an outer
shell having first and second ends, with the pan defining an interior volume, and
at least one partition within the shell, dividing the interior volume into a plurality
of coating vessels and generally preventing the intermixing of the separate masses
of centers, wherein each coating vessel has at least one aperture for the introduction
of a mass of centers and a coating composition into each coating vessel;
introducing the mass of centers to be coated into each of the coating vessels,
wherein the masses of centers in different coating vessels may be the same as or
different from each other;
optionally, measuring each mass of centers to provide masses of centers that
vary in weight, one from the other, by no more than about 2 percent;
rotating the coating pan;
generally preventing cross-over and intermixing of centers between coating vessels
with the partition;
introducing a coating composition into each of the coating vessels, wherein each
coating composition introduced into different coating vessels may be the same as
or different from one another;
intermixing the mass of centers and coating composition in each coating vessel
to form a coating layer on each of the centers; and
drying the coating layers.
2. The method of claim 1, wherein at least one coating composition introduced
into a coating vessel is different from at least one other coating composition
introduced into another coating vessel in the coating pan; or
at least one mass of centers introduced into a coating vessel is different from
at least one other mass of centers introduced into another coating vessel in the
coating pan; or
at least one coating composition introduced into a coating vessel is different
from at least one other coating composition introduced into another coating vessel
in the coating pan, and at least one mass of centers is different from at least
one other mass of centers introduced into another coating vessel in the coating
pan.
3. The method of claim 1, further comprising the steps of:
providing apertures in each of the first and second ends of the coating pan;
and
introducing the masses of centers into the coating vessels through the apertures
provided in the first and second ends.
4. The method of claim 1, wherein the drying step comprises drying the coating
layer with a drying gas.
5. The method of claim 4, wherein the drying gas is dry air.
6. The method of claim 1, wherein the masses of centers are chocolate, and the
coating composition is a sugar solution that is optionally a colored sugar solution.
7. A panning apparatus comprising:
a split-pan comprising a hollow drum, having first and second ends, the drum
defining an interior volume, and at least one partition, positioned between the
first and second ends, thereby dividing the interior volume into a plurality of
coating vessels, each coating vessel configured for coating a separate mass of
centers, and thereby preventing the general intermixing of the separate masses
of centers,
wherein each coating vessel has at least one aperture for the introduction of
the mass of centers and a coating composition into each coating vessel; and
at least one coating application mechanism, configured to apply a coating composition
to centers in at least one of the coating vessels,
wherein said at least one coating application mechanism is a single spray manifold
including separate feed lines and nozzles for each coating vessel or a plurality
of spray manifolds, each spray manifold individually configured to spray coating
composition on centers in a single coating vessel in the split-pan.
8. The panning apparatus of claim 1, wherein a single partition is positioned
between the first end and the second end, such that the partition divides the interior
volume into a first coating vessel between the first end and the partition and
a second coating vessel between the partition and the second end.
9. The panning apparatus of claim 1 further comprising a plurality of chutes,
each configured to introduce a mass of centers into one of the coating vessels.
10. A panning apparatus comprising:
a split-pan comprising a hollow drum, having first and second ends, the drum
defining an interior volume, and a partition, mounted in the drum between the first
and second ends, thereby dividing the interior volume into a first coating vessel
between the first end and the partition and a second coating vessel between the
partition and the second end, and thereby preventing the general intermixing of
masses of centers in the first and second coating vessels,
wherein each coating vessel has at least one aperture for the introduction of
a mass of centers and a coating composition into each coating vessel; and
at least one coating application mechanism, configured to apply a coating composition
to centers in at least one of the coating vessels,
wherein said at least one coating application mechanism is a single spray manifold
including separate feed lines and nozzles for each coating vessel or both a first
spray manifold configured to spray a coating composition on centers in the first
coating vessel and a second spray manifold configured to a spray coating composition
on centers in the second coating vessel.
11. The panning apparatus of claim 10, further comprising a first chute configured
to introduce centers into the first coating vessel, and a second chute configured
to introduce centers into the second coating vessel.
12. A method of improving axial mixing of a mass of centers in a coating pan
in a coating apparatus, the coating pan comprising an outer shell, having first
and second ends, the shell and the ends defining an interior volume, the method comprising:
providing at least one partition within the shell, wherein the partition divides
the interior volume into a plurality of coating vessels, each coating vessel configured
for coating a separate mass of centers, and wherein the partition generally prevents
cross-over and intermixing of centers between coating vessels, and improves axial
mixing of the mass of centers in the coating pan when the coating pan is rotated;
wherein each coating vessel has at least one aperture for the introduction of
the mass of centers and a coating composition into each coating vessel; and
wherein the coating apparatus further comprises at least one coating application
mechanism, configured to apply a coating composition to centers in at least one
of the coating vessels, said at least one coating application mechanism being a
single spray manifold including separate feed lines and nozzles for each coating
vessel or a plurality of spray manifolds, each spray manifold individually configured
to spray coating composition on centers in a single coating vessel.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to coating pans and to panning apparatus
used to produce coatings or shells on a mass of centers. In particular, the present
invention relates to a split-pan for a panning apparatus and to a panning apparatus
incorporating a split-pan that provide for the simultaneous coating of different
masses of centers with different coatings in a single apparatus, such that the
different center/coating combinations are not intermingled or mixed.
2. Related Background Art
Panning and film coating are related industrial processes for preparing coated
centers. Typically, the term "panning" is used with regard to the application of
sugar-based coatings, such as, e.g., sucrose and dextrose to masses of centers.
The term "film coating" is used with regard to application coatings that are not
based on sugar to masses of centers. However, the basic processes used in panning
and film coating are substantially the same. Each process comprises the repetitive
application of thin layers of a coating solution or composition onto an intermixed
mass of centers, while mixing the mass of centers, and the drying of each layer
of coating solution or composition. Each process is performed in a rotating drum
or "pan". Panning often comprises three distinct repeating steps; namely, application
of the coating solution, distribution of the coating solution on the centers, and
drying the coating solution. In contrast, the film coating process often comprises
the simultaneous application, distribution, and drying of the coating solution.
However, in each process, thin layers of coating material are built up on the center
with each application to form the desired shell or coating. The application, distribution,
and drying steps may be performed simultaneously or sequentially.
Panning and film coating are used to apply coatings to a variety of different
types of centers, including, but not limited to, pellets, tablets, pills and molded
or granulated products. Examples of coated centers include pharmaceuticals in the
form of pills, tablets, and the contents of time-release capsules; chemical products,
such as detergents; and foodstuffs, such as candy. Coatings are typically used
to prevent degradation and decomposition of the centers from exposure to air and
humidity, to give the coated object a decorative appearance, and have been known
to prevent the melting of certain chocolate candies in consumer hands.
Panning and film coating apparatus and processes performed by them for coating
centers are well known in the art. A typical panning or film coating apparatus
comprises a coating pan and mechanisms for introducing a coating solution and a
drying gas into the pan. A mass of centers is introduced into the coating vessel.
The mass of centers is then intermixed, a layer of the coating solution is applied
to the centers, and the coating layer is dried with the drying gas. The coating
may be dispersed by spraying or pouring the coating solution onto the mass of centers.
Applying the coating solution while intermixing the mass of centers prevents the
coated centers from adhering to each other, and helps insure uniformity. The drying
gas, which is often dry air, may be introduced simultaneously with or subsequent
to the application of the coating solution.
For example, U.S. Pat. No. 2,652,805 to D'Angelo discloses an apparatus for coating
tablets, pills, and other small objects. The disclosed coating apparatus comprises
a rotating drum, a drive motor, and optionally, one or more blowers. Pills or tablets
placed in the drum are tumbled or intermixed by the rotation of the drum. A coating
material, added to the drum, is distributed onto the surface of the pills or tablets.
Multiple coats of one or more coating materials may be applied with the apparatus.
U.S. Pat. No. 3,357,398 to Gross discloses a method and apparatus for coating
tablets. The apparatus comprises a tiltable perforated drum or pan mounted on a
shaft within a housing, a drive motor, and a mechanism for forcing a drying medium,
i.e., air, through an inlet in the housing, through the perforated pan, and out
an outlet. Tablets are loaded in the perforated drum, which is then rotated to
mix them. An atomized coating material is sprayed onto the tablets and the drying
medium is passed through the inlet and the perforated drum, as the tablets are mixed.
U.S. Pat. No. 4,245,580 to Okawara discloses a device for coating granular solids.
The apparatus comprises a double-cone rotary drum, which is perforated to permit
the flow of gas through the drum, a drying gas supply, a drying gas exhaust, annular
insulating covers for the drum, and mechanisms for tilting and changing the height
of the drum to facilitate loading and unloading. Coating material is sprayed on
granular material in the drum, and the drying gas is passed through the drum, as
the drum rotates.
U.S. Pat. No. 5,495,418 to Latini et al. discloses an automatic panning system
that comprises a rotatable drum in which a mass of centers is tumbled and coated
with a solution to form a shell, a spray arm for applying a coating solution, an
air flow system to provide a drying air flow, and control means. The coating process
consists of the repetition of separate spraying, distribution, and drying cycles
in which the condition of the air, the drum speed, and the cycle timer are monitored
and controlled by the control means.
However, every known prior art film coating and panning apparatus, such
as those described briefly above, allows coatings to be applied to just one mass
of centers at a time. Because of the nature of such apparatus, and the process
that they perform, a coating material introduced into the coating pan or drum is
applied to substantially all of the centers in the mass. Therefore, during production,
a different panning apparatus is required for each combination of coating and center
that is prepared at any given time. To increase the number of center/coating combinations
that can be simultaneously processed using prior art pans requires additional panning
apparatus, which, in turn, requires additional capital costs and space. Therefore,
a need exists for a panning apparatus that can process two or more center/coating
combinations simultaneously. The present invention provides such an apparatus.
SUMMARY OF THE INVENTION
The present invention overcomes the deficiencies of the prior art, discussed
above, and provides a novel apparatus and method for coating two or more masses
of centers simultaneously. The present invention is directed to a split-pan for
a panning apparatus, to a panning apparatus comprising the split-pan of the invention,
and to a method of simultaneously coating two or more separate masses of centers
in a single panning apparatus. The split-pan of the invention comprises a hollow
drum, having first and second ends, the drum defining an interior volume; and at
least one partition positioned between the first and second ends. The partition
divides the interior volume of the split-pan into a plurality of coating vessels.
In a preferred embodiment, the split-pan comprises a single partition positioned
between the first end and the second end, such that the partition divides the interior
volume into a first coating vessel between the first end and the partition and
a second coating vessel between the partition and the second end. Preferably, the
first end of the drum defines a first end aperture, and the second end of the drum
defines a second end aperture, where each of the first and second end apertures
are of a size sufficient to permit introduction of masses of centers into the plurality
of coating vessels. However, any means known in the art for introducing masses
of centers into the coating vessels may be used. In addition, the partition preferably
defines an aperture, configured to allow passage of a drying gas, and sized generally
to prevent cross-over and intermixing of centers between coating vessels.
A panning apparatus comprising the split-pan of the invention preferably further
comprises a plurality of chutes configured to introduce centers into the coating
vessels. At least one coating application mechanism is preferably also provided
to apply a coating solution, composition, or mixture to centers in at least one
of the coating vessels. Each coating application mechanism is preferably a spray
manifold, which may have separate feed lines and nozzles for each coating vessel.
Alternatively, a plurality of spray manifolds may be utilized, where each spray
manifold is individually configured to spray coating solution or composition on
centers in a single coating vessel in the split-pan.
The method of the invention for simultaneously coating two separate masses of
centers comprises providing a coating apparatus, comprising the split-pan coating
pan of the invention, introducing a mass of centers to be coated into each of the
coating vessels in the split-pan, rotating the coating pan, introducing a coating
solution or composition into each of the coating vessels, intermixing the mass
of centers in each coating vessel to form a coating layer on each of the centers,
and drying the coating layers. At least one coating solution or composition introduced
into one coating vessel may be different from another coating solution or composition
introduced into another coating vessel in the coating pan. Similarly, at least
one mass of centers introduced into one coating vessel may be different from at
least one other mass of centers introduced into at least one other coating vessel
in the coating pan. In addition, at least one coating solution or composition introduced
into one coating vessel may be different from at least one other coating solution
or composition introduced into another coating vessel in the coating pan, and at
least one mass of centers may be different from at least one other mass of centers
introduced into another coating vessel in the coating pan.
The method of the invention may further comprise introducing the masses of centers
into the coating vessels through apertures defined by the first and second ends
of the coating pan, drying the coating layer with a drying gas, where the drying
gas may be, for example, dry air, and/or measuring each mass of centers to provide
masses of centers that vary in weight, one from the other, by no more than about
2 percent. In a preferred embodiment, the masses of centers are chocolate, and
the coating solution is a sugar solution, such as a colored sugar solution.
The apparatus and method of the invention also improve the homogeneity of mixing
in a coating pan in a coating apparatus by improving axial mixing in the coating
pan. Axial mixing occurs near the side walls that are formed by the ends of a coating
pan. By positioning at least one partition within a coating pan, the split pan
of the invention introduces two additional walls into the pan for each partition.
Therefore, when the pan is rotated, the partition improves the axial mixing of
a mass of centers and coating composition in the coating pan, and improves the
homogeneity of the coating on the centers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration of a split-pan in accordance with a preferred
embodiment as shown in present invention;
FIG. 2 is a cross-sectional view of the split-pan taken on plane 2—2
in FIG. 1;
FIG. 3 is a plan view of a segmented partition of a split-pan in accordance
with a preferred embodiment of the present invention;
FIG. 4 is a plan view of a segment of the partition shown in FIG. 3;
FIGS. 5
a and 5
b are opposite end views of the partition
segment shown in FIG. 4;
FIG. 6 is a cross-sectional view of the joint between two partition segments
taken on plane 6—6 in FIG. 3;
FIG. 7 is an illustration of a spray manifold useful with the split-pan of FIG. 1;
FIGS. 8
a and 8
b are cross-sectional views of a spray manifold
for a split-pan panning apparatus of the invention respectively taken on planes
8
a-8
a and 8
b-8
b in FIG. 7;
FIG. 9 is an illustration of a syrup supply manifold for one set of nozzles
of the spray manifold shown in FIG. 8; and
FIG. 10 is an illustration of a syrup supply manifold for a second set of nozzles
of the spray manifold shown in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "pan" refers to a coating vessel, drum, or pan for use
in a film coating or panning process. The term "panning" refers to a coating or
panning process. The term "panning apparatus" refers to an apparatus for panning
or film coating incorporating a pan. Thus, for purposes of describing the present
invention, no distinction is made between such apparatus and processes used to
apply sugar-based and non-sugar based-coatings.
The present invention is directed to a split-pan for use in a panning apparatus,
a coating or panning apparatus comprising the split-pan in accordance with the
invention, and to a method of simultaneously coating at least two separate masses
of centers. The split-pan of the invention may be used to coat pellets, tablets,
pills and molded or granulated products, such as, for example, pharmaceuticals
in the form of pills, tablets, and the contents of time-release capsules; chemical
products, such as detergents; and foodstuffs, such as candy, including chocolate,
and confectionaries. Coatings that may be applied include those that prevent degradation
and decomposition of the centers from exposure to air and humidity and/or provide
a decorative appearance to the coated object, such as, for example, by providing
a decorative or appealing color. The coatings may be any appropriate inorganic
or organic coating material. Preferably for candy such as chocolate, and other
confectionaries, the coating is formed from a sugar, such as, for example, sucrose,
fructose, or dextrose.
A typical prior art panning apparatus comprises a rotating pan, a hopper for
storing
and/or measuring a mass of centers prior to their introduction into the pan, a
chute for introducing the mass of centers into the pan, a spray arm or other device
for introducing a coating solution or composition into the pan, and other ancillary
equipment, such as, for example, one or more drive motors for the pan, a drive
mechanism that can include gears and/or pulleys and belts or the like, and electronic controls.
The split-pan of the invention differs from prior art coating pans in that the
split-pan provides at least two coating vessels in a single pan structure. This
construction provides for the simultaneous application of one or more coatings
to two or more separate masses of centers, where, preferably, one of the masses
of centers and/or one of the coatings are different from the other centers and/or
coatings. However, as will be understood by those skilled in the art, with the
split-pan of the present invention, it is possible to coat a single type of center
with a single type of coating by placing the same type of center in each vessel
of the split-pan, and applying a single coating to all the centers. Therefore,
the number of combinations of centers and coatings that can be processed simultaneously
ranges from one up to the total number of coating vessels in the split-pan.
A split-pan
10 in accordance with the invention is illustrated in FIGS.
1 and 2, where FIG. 1 is a perspective view, and FIG. 2 is a cross-sectional view
taken on plane
2—
2 as noted. Split-pan
10 comprises
an outer shell or drum
12, having first and second ends
14 and
16,
and a partition
18. Centers may be introduced into split-pan
10 by
any convenient means known in the art, such as through the discharge gates (not
shown) or chutes typically found in the outer shell or drum of prior art pans.
Preferably, as illustrated in FIGS. 1 and 2, in the split-pan apparatus of the
invention, centers are introduced through chutes
21 and
23. For existing
equipment that is modified by the addition of one or more partitions to form a
split-pan, it will be necessary to modify the panning apparatus to allow the introduction
of multiple masses of centers. This may be accomplished by the addition of one
or more additional chutes, and/or the shell or drum
12 may be modified to
add one or more additional discharge gates to allow access to coated centers in
each section formed within the split-pan by the partitions.
As illustrated in FIGS. 1 and 2, split-pan
10 has a single partition
18,
dividing it into first and second coating vessels
20 and
22, where
centers are introduced into vessel
20 by chute
21, and into vessel
22 by chute
23. However, as will be understood by those of ordinary
skill in the art, more than one partition may be used to further divide split-pan
10 into additional coating vessels. The restraints on the number of partitions
and vessels are typically space related. For example, as the number of partitions
and vessels increase, additional chutes and/or discharge gates are required to
introduce a mass of centers into each of the coating vessels. For a given coating
apparatus, the number of gates and/or chutes is limited by the amount of space
available in, on, and around the apparatus. Moreover, the mechanism used to supply
coating solutions to the centers in the split-pan, such as, for example, a spray
manifold, becomes more complex if a different coating solution is to be used with
each coating vessel.
Preferably, first and second ends
14 and
16 of drum
12,
respectively, are formed with first end aperture
15 and second end aperture
17, to allow the introduction of centers into coating vessels
20
and
22 by first and second chutes
21 and
23. Also, partition
18 preferably defines aperture
19 to allow a drying gas to pass through
split-pan
10. Aperture
19 is preferably sized to generally eliminate
cross-over of centers from one coating vessel to the other during a panning process.
Where split-pan
10 is a new construction, partition
18 may be
formed of a single piece, as it may be installed during the assembly of the pan.
For existing equipment, however, a partition formed from a plurality of pieces
may advantageously be provided, as the installation requires passing the partition
pieces through at least one of apertures
15 or
17, unless one of
ends
14 and
16 is removable. If the partition is assembled from arc
segments, as described below, the minimum number of such segments that is required
is determined by the diameters of split-pan
10 and of end apertures
15
and
17. That is, each arc segment
24 shown in FIG. 3 must have at
least one dimension, other than thickness, that is less than the diameter of end
apertures
15 and
17. As can be seen in FIG. 3, partition
18
is formed from 10 arc segments
24 in accordance with the preferred embodiment.
However, any convenient number may be used within the constraint noted above.
An assembled segmented partition
18, useful in the invention, is illustrated
in FIG.
3. As noted, in the preferred embodiment, segmented partition
18
comprises a plurality of interconnected arc segments
24 of the type illustrated
in FIG.
4. Each arc segment
24 may be formed from a single sheet
of any useful material known in the art, such as metal or composite. Preferably,
each arc segment
24 is formed from stainless steel, and, more preferably
12 gauge type
33 stainless steel. Although each arc segment
24 may
be formed from a single sheet of material
25, it is preferably formed from
a pair of panels
25a and
25b spaced by one or more
sections of flat bar, which is preferably of the same material as that used to
form panels
25a and
25b. This construction provides
strength and durability. Where arc segments
24 are formed from steel, at
least one section of flat bar
27 may be welded between panels
25a
and
25b along inner circumferential section
29, and at
least one section of flat bar
27 may be welded between panels
25a
and
25b along outer circumferential section
30 to form
each arc segment
24. The required number of segments are then assembled
within drum
12, and welded together at joints
31 between adjacent
segments, as illustrated in FIG. 6, and bolted or welded into place within split-pan
10 using panel joints
32 shown in FIG.
3.
At least one coating solution application apparatus is required to introduce
coating
solution into the coating vessels within split-pan
10. A single apparatus
that provides a coating solution or mixture to multiple coating vessels may be
used, or a separate coating solution application apparatus may be used for each
coating vessel or for a group of coating vessels. The apparatus may be of any useful
type known in the art. Individual units may be used for each coating vessel, or
a single combined unit may be used.
In one preferred embodiment, the coating solution application apparatus comprises
a single spray manifold
34, such as that illustrated in FIG.
7 and
in FIGS. 8
a and
8b in the form of a single, combined unit.
Syrup supply manifolds for each of coating vessels
20 and
22 in split-pan
10 are illustrated in FIGS. 9 and 10 and form a part of the manifold as
described below.
Spray manifold
34, as illustrated in FIGS. 7 and 8
a and
8b,
comprises an outer tube or jacket
35 and a plurality of nozzles
36.
Each coating vessel in split-pan
10 is supplied by a separate group of nozzles.
As illustrated in FIGS. 7 to
10, first vessel nozzles
38 are supplied
with syrup through first vessel feed line or syrup supply
40 for introduction
into first coating vessel
20, and second vessel nozzles
39 are supplied
with syrup through second vessel feed line or supply
41 for introduction
into second coating vessel
22. First vessel nozzles
38 and first
vessel syrup supply
40 together form first vessel syrup supply manifold
42, and second vessel nozzles
39 and second vessel syrup supply
41
together form second vessel syrup supply manifold
43. First and second syrup
manifolds
42 and
43 are assembled by being inserted into jacket
35,
preferably with trace line
44, to form spray manifold
34. Hot water
may be introduced through trace supply
45 into trace line
44 to maintain
spray manifolds
42 and
43 at a temperature sufficiently high to prevent
sugar in the syrup in manifolds
42 and
43 from precipitating or otherwise
solidifying or crystallizing, and, thereby, prevent clogging any of nozzles
36
or syrup supplies
40 and
41. Preferably, the temperature of the water
should be about 80° C. Trace return
46 is provided to allow the hot
water to flow out of trace line
44 and to be reheated.
As will be understood by those skilled in the art, a typical prior art panning
apparatus comprises a rotating pan, having an aperture in at least one end, and
a chute/hopper combination for introducing a mass of centers into the pan. In the
present invention, however, as at least two separate masses of centers must be
introduced into split-pan
10. Preferably, this is accomplished using multiple
chutes. However, as will be recognized by those skilled in the art, the delivery
of each mass of centers to a separate coating vessel may be accomplished with a
single movable or variably extendable chute, or by any other means know in the
art, including, but not limited to, manually loading a mass of centers into each
coating vessel. A single hopper may be used to introduce masses of centers into
multiple chutes, or a separate hopper may be used to introduce a mass of centers
into each chute. If the split pan apparatus in accordance with the invention is
to occupy no more space than a conventional single pan prior art apparatus, then
each coating vessel
20 and
22 will be about one-half the size of
a single pan prior art vessel. In such a case, each mass of centers introduced
into split-pan
10 will likely be no more than half as large as the mass
introduced into a prior art single pan, so that, if two hoppers are employed, hopper
48 need be no larger than half the size of a hopper used with a typical
single prior art panning apparatus.
A split-pan apparatus of the invention having a single partition and two coating
vessels functions as follows. Two charges of centers, which may be the same as
or different from each other, are preferably weighed and separately loaded into
a pair of hoppers positioned on opposite ends of a coating pan. The centers may
be loaded into the hoppers by any means known in the art, such as by using a loss-in-weight
feeder. The size of each charge is usually, but not necessarily, substantially
the same for each coating vessel in the split-pan. Most preferably, the variation
in the masses is no more than about 2 percent. Each hopper communicates with one
of the coating vessels through a chute, such that, when a release mechanism on
each hopper is operated, the mass of centers in each hopper flows through the corresponding
chute and into the corresponding coating vessel of the split-pan. The split-pan
is then rotated, and a coating solution or mixture is introduced into each coating
vessel, through the spray manifold, where the coating solution introduced into
one coating vessel may be the same as or different from that introduced into the
other coating vessel. The coating solution or mixture is ordinarily introduced
into each coating vessel in an amount sufficient to produce a thin coating on each
of the centers in that vessel. A drying gas, such as dry air, is thereafter allowed
to flow through the apertures of the split-pan and the partition, drying the coatings
on the centers. Once the coatings have dried sufficiently, an additional coating
may be applied to the centers in the same fashion as described above, and the process
is repeated until a final coating of the desired thickness is obtained. Preferably,
at least one coating solution introduced into a first coating is different than
the coating solution introduced into a second vessel. More preferably, the coating
solutions will differ in color. Also, the centers will preferably be confectionery,
e.g., chocolate, peanut, peanut butter, or rice centers.
Where different coating solutions or mixtures are used, the coating solutions
or mixtures should be compatible. In particular, the drying rates for the coating
solutions or mixtures used in the split-pan should be equivalent, so that the coating
on each mass of centers in the pan drys at substantially the same rate. For example,
for color coating candy centers, different "Lake" color coatings may be used together
because such coatings have similar drying rates. Different dye colors may also
be used simultaneously, again, because they have similar drying rates.
The split-pan of the invention also provides improved axial or lateral mixing,
which results in more homogeneous mixing of the centers in the pan. Two types of
mixing occur within a coating pan. The first is radial mixing in which a mass of
centers in the pan is mixed along the radius of the pan, i.e., through the depth
of the mass of centers, by the rotation of the pan. However, radial mixing alone
is not sufficient to provide a mass of homogeneously coated centers in a coating
pan, as an even distribution of coating solution along the axis of the pan is difficult,
if not impossible, to obtain for a large mass, i.e., on the order of a ton, of
centers. Obtaining a uniform spray distribution will clearly improve the homogeneity
of the coated centers, but the uniformity of the spray distribution is difficult
to control with a large coating pan. Therefore, to obtain a mass of homogeneously
coated centers, axial mixing, in which the centers are mixed along the length or
axis of the pan, is also required. To obtain axial mixing, prior art coating pans
include internal baffles and tunnels to force centers to move from side-to-side
within the pan. However, the use of baffles and tunnels makes cleaning of the interior
of the pan significantly more difficult.
It has been found that improved axial mixing occurs near the side walls that
are
formed by the ends of a coating pan. By positioning at least one partition within
a coating pan, the split pan of the invention introduces two additional walls into
the pan for each partition, thus, improving axial mixing. Therefore, the split-pan
of the invention is useful when a single mass of centers is coated with a single
coating solution or composition.
The numbers of revolutions of a coating pan required to obtain a substantially
uniformly coated mass of centers is a measure of the amount of axial mixing in
the pan. In a typical prior art coating pan, the number of revolutions required
to obtain a substantially uniformly coated mass of centers is greater than 500.
In contrast, with the split-pan of the invention, the number of revolutions required
to obtain a substantially uniformly coated mass of centers is less than 500, and
can be significantly less than 100. Preferably, the number of revolutions required
to obtain a substantially uniformly coated mass of centers is less than 400, more
preferably, less than 300, and, most preferably, less than 200.
Accordingly, it will be appreciated that the present invention has been
described with references to particular preferred embodiments that are now contemplated.
However, the invention is not limited by the embodiments disclosed herein and it
will be appreciated that numerous modifications and other embodiments may be devised
by those skilled in the art. Therefore, it is intended that the appended claims
cover all such modifications and embodiments that fall within the true spirit and
scope of the present invention.
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