Note: Descriptions are shown in the official language in which they were submitted.
10543 4Z
This invention relates to an improved mixing and whipping
apparatus and method whereby emulsified ingredients are more
consistently whipped to a predictable and controllable volumet-
ric overrun.
One of the most common pieces of equipment employed in
unit operations is a planetary mixing whipper which may be
variously equipped with whips and beater knives or arms opera-
tive to effectively hydrate, intermix, whip and eventually
generate a uniform pattern of distribution in a liquid medium.
One of the more frequent applications for such devices is food
processing wherein emulsions are converted into a high overrun
for sale as toppings and like oil-in-water systems wherein air
is incorporated to provide a uniform and delicate light texture
to a product. In such food applications where the ultimate
composition is sold as such, it is imperative that control of
the volume of the comestible and like goods be exercised inas-
much as such compositions are customarily volumetrically filled
and hence require consistent overrun meeting declared weight
label tolerances. --
So far as is presently known, agitator whippers and methods
of employing same are not specially designed to provide such
control as would permit a processor to enjoy manufacturing
economies by more consistently meeting close overrun tolerances.
Thus, it becomes desirable in manufacturing a topping and like
overrun comestible to have a whipper that will serve to generate
a predictable overrun by reason of a more consistent viscosity
development. -
To explain further, the whipping of aqueous suspensions ~ -
and solutions and like liquid preparations will achieve a
decrease in viscosity as the solids become hydrated. The tines
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on a typical wire whip which turn at high speeds serve to
promote overrun and viscosity changes for the liquid medium.
With continued whipping and churning the liquid medium is
inclined to partition into a relatively high viscosity phase
and a less viscous one. Such phase separation in mixing is not
desired since it gives rise to eccentricities in viscosity and
unpredictability in whip volume. While whip agitators have
been designed with planet~ry movements within the mixing bowl
in order to promote uniform mixing, there has nevertheless been
a tendency for the liquid phase to segregate into a less viscous
and a more viscous condition with consequent unpredictabilities
in generating overrun. It would be desirable for quantity
production at reduced cost to continuously feed liquid at the
bottom of a planetary whipper's bowl and withdraw the whipped
product as an overflow from the bowl. But when employing such
a system viscosity variations greatly limit the ability to meet
manufacturing tolerances as aforesaid.
It is, therefoxe, among the objects of the present inven-
tion to ameliorate such eccentricities and variations and
provide a method whereby a liquid such as a topping or other
aqueous emulsion composition can be consistently aerated to a
high overrun state incident to which agitation there will be a
more uniform viscosity development. A more specific objective
is to provide a continuous whipper agitator which possesses
these operating characteristics whereby a liquid medium can be
charged to the whipping zone and continuously withdrawn as an
overflow at a predictable overrun.
This invention is founded upon the discovery that baffling
means can be advantageously located within the locus defined
by the rotating tines of a given whip in a planetary whipper.
1054~4Z
In accordance with the present invention, an
agitator whipper is provided which comprises a bowl and
a tine whipper assembly mounted for planetary movement in
said bowl. The assembly comprises a plurality of tines
mounted on a common, generally vertical shaft and baffle
means also mounted on said shaft within the perimeter defin~d
by said tines, said baffle means being of sufficient radial
width to intercept, obstruct and deflect liquid ascent within
said assembly, said baffle means comprising a plurality of
generally plate-shaped baffles, each of said baffles having
a leading edge and a trailing edge and being inclined at an
acute angle relative to a horizontal plane such that each
respective baffle slopes downwardly generally in the direction
from its leading edge to the trailing edge thereof, and
means for admitting a whippable composition intermediate
the bowl wall and said assembly at a location beneath said
assembly, whereby said baffle means restricts axial flow
within said assembly, whereln the bowl has an entry port
proximate the lower extremity thereof adapted to continuously
receive a liquid charge and wherein the bowl has an exit port
at its upper extremity adapted to continuously overflow liquid .
whipped in said agitator, said apparatus comprising two pairs
of said baffles, said pairs being axially spaced sufficiently
from one another to permit lower density liquid deflected from
a lower baffle pair through the tines to reenter the locus ~-
of the rotating whipping tines and be acted upon by a
superjacent baffle pair.
According to another aspect of the present
invention, a method is provided of whipping by charging
liquid to a mixing bowl wherein a tine whipper assembly is
mounted for high speed rotation with a planetary movement
and creates a whipping zone within the bowl, the improvement
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which comprises creating a plurality of baffling zones for
the liquid passing the tines, liquid being caused to enter
each of said baffling zones from said whipping zone and
being redirected radially back through said whipping zones to
a zone external to the locus of the rotating tines at a
reduced density whereby said reduced-density liquid rises in
the mass thereof, continuing said rotation and movement and
causing said risen liquid to reenter and pass the whipping
zone to reenter the area within the rotating tines and occupy
a second baffling zone superjacent the first zone wherein
the liquid is redirected radially and is again returned
through the whipping zone at a still lower density.
Referring to the accompanying drawings of the agitator of
this invention,
Fig. 1 is a front elevation view of a planetary mixer
equipped with the whipper of the invention;
Fig. 2 is a side elevation view of the same device;
Fig. 3 is a top plan view with parts broken away at a
plane just above the mixing bowl of the device;
Fig. 4 is an enlarged sectional elevation view of the
agitator vessel showing the whipping structure in place;
Fig. 5 is a still further enlarged elevational view of
the whipping assembly per se;
Fig. 6 is a top plan view of the assembly in Fig. 5 taken
along line 6-6; and
Fig~ 7 is a perspective view of baffle means in the
whipper assembly.
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Referring to Figs. 1-3, the agitator whipper drive and
mixing vessel will be seen to comprise a conventional planetary
mixer having a base 1 and pedestal 2 mounting a motor 3 driving
through a planetary gear train 4 an agitator shaft mount 5 -
within bowl 6 mounted on a bowl support 7 adapted to be lifted
by lift screw means 8 for spatially adjusting bowl and agitator
placement. -
Referring particularly to Figs. 4-7 detailing the most
preferred form of agitator whipper, it will be noted that the
agitator generally comprises a wire whip 10 consisting of a
plurality of tines 12 assembled to form upon rotation the locus
of a cylinder that converges at one end to a semi-sphere, the
tines being permanently anchored at their lower extremity 14
upon shaft extremity 16 and being mounted at their upper ex-
tremity or free end upon a disk 18 also fixedly mounted upon
shaft 16 for rotation therewith all of which constitutes prior
art but which in cooperation with the elements of the present
invention are intended to provide a specific operative effect.
The disk 18 has perEorations formed therein for weight reduction
and minimizing load upon the whipper assembly per se.
the shaft has mounted thereon a plurality of planar radial
baffles 20, each baffle being fixedly mounted upon shaft 16; the
baffles may be adjustably mounted if liquids of varying mixing -
characteristics are used. The shape of each baffle is such
that it has sufficient planar width radially of shaft 16 to
intercept, obstruct and deflect flow of liquid as will be
described hereinafter. The baffles rotate within the perimeter
or confines of whip tines 12 and are spaced at their lateral
free edges from the tines. The lower baffles as shown for
instance at 22 in the semi-spherical region of the whip-locus
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are accurately shaped so as to similarly terminate short of the
tines but be substantially complementary thereto so that the
assembly of baffles in both the cylindrical and semi-spherical
section of the whip are in a close proximity at their lateral
free edges to the corresponding regions of the tines in the
whip assembly.
The baffles rotate in the whip assembly in a counter-
clockwise direction as shown in Fig. 6, the whip-assembly being
mounted for planetary clockwise rotation within bowl 6 and form-
ing what is referred to herein as a whipping zone. The bowl
comprises a cylindrical wall portion 26 and a semi-spherical
portion 2~. The whip-baffle assembly rotates as seen in Figs.
1-3 in a generally circular path proximate but spaced from the
bowl wall as shown in Fig. 4. The liquid such as a topping
emulsion is fed continuously to the lower regions of the mixing
bowl through port 30. With continuing rotation of tines 12 the
emulsion passes therethrough at the semi-spherical regions
thereof and is deflected by the lower pair of baffles 22 forming
what is referred to herein as a first baffle zone. With
continued uniform feeding of emulsion through port 30 the
aerated emulsion undergoes an incremental viscosity change as
the vessel is filled and continued to be operated as one pro-
ceeds from the outer extremity to the inner extremity of the
bowl. Thus, the emulsion within the locus of the whip but t
proximate the shaft is less viscous than the regions proximate
the tines.
Advantageouslyl by virtue of the baffles arrangement as
shown, emulsion viscosity irregularities are minimized as the
emulsion is intercepted by each of the baffles and is deflected
axially downwardly and radially. The emulsion in turn is pumped
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or redirected in the direction of the tines and then radially
outwardly through the locus defined by the tines. With con-
tinued rotation of the shaft, the emulsion overrun increases
and it rises within the region intermediate the lateral free
edges of the baffles and the bowl wall. With rotation con-
tinued further and cavitation induced by the baffles, the -
emulsion is reintroduced to within the perimeter of the tines of
the whip to again be intercepted in a second baffle zone by a
superad~acent baffle pair and is again deflected. Thus, as
rotation proceeds and the emulsified composition undergoes
progressive density reduction and as successive supervening
baffles intercept and deflect the rising emulsion there results -~ -
a complete and uniform mixing. The resulting emulsion viscosity
is quite uniform. The baffles themselves function to regulate -
ascent of the emulsion to a pre-determined height whereat the
intended overrun and density reducity is determinable by the
ascent of the emulsion within the bowl. Consequently, the
emulsion can be withdrawn as an overflor by decantation through
a weir generally shown as 32 mounted in an opening in the ves-
sel wall 34. The axis of ratation of the wirebaffle assembly
and of the bowl is at an acute angle to the vertical in order '
to tilt the bowl and thereby assure positive displacement of
the emulsion to and through the weir. So controllable is the
overrun the emulsion can be predictably decanted at a given
height in wall 26 and correlatable with a specified emulsion
overrun.
This permits the agitator-whipper to be operated continu-
ously with charge emulsion being introduced through orifice 30
and being continuously withdrawn through overflow weir 32 while
at the same time achieving a predictable consistent viscosity,
density reduction and overrun.
105414Z
Overflow is very uniform across the perimeter of the weir
opening by reason of the homogenous character and distribution
of product.
Baffles 20 and 22 will generally be poised so that a pair
of baffles will be mounted at the same level on shaft 16; the
baffle planes will intersect at an acute angle with respect to
one another (alpha) as well as with respect to the shaft (beta),
the shaft intersect angle (beta) as well as the baffle intersect
angle (alpha) being functions of the particular emulsion. The
respective shaft intersect and baffle intersect angles for each
pair of baffles will preferably be the same. In this connection,
superjacent pairs of baffles will be mounted on the shaft
offset from one another at the lines of intersection of the baf-
fle planes. Thus, the planes of a pair of baffles mounted at a
given height on the shaft will be at an angle preferably in the
order of 90 to the corresponding intersect lines of a super- r
jacent baffle pair. In this way, superjacent pairs divide
the mixing area into a plurality of mixing and whipping regions,
the number of such region being determined by the whipping t
required for a given emulsion. Generally, at least two and
preferably three baffle pairs will be mounted for rotation with-
in the cylindrical locus of the tine-wire assembly and one
baffle pair of like shaft-fixation will be located within the
hemispherical region of said locus.
Viewed axially as shown in Fig. 5, the deflecting zone of
the baffles in a given pair thereof will be spaced preferably
from the deflecting zone of an adjacent pair of baffles such
that there will be a space axially between superjacent adjoining
baffles; this spacing will be a function of the intended and
desired mixing, the space between adjacent baffles being
sufficient to promote such mixing.
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1~5~14Z
Although the invention has been described in reference to
the foregoing drawings in connection with a particular wire whip
configuration, an agitator that is non-cylindrical may similarly -
be equipped with a wire whip having different geometric pattern
all within the same inventive spirit. Thus the whip may define
the locus of a sphere, an ellipsoid, a hemi-ellipsoid or the --
envelope of a spiral's rotation. Although not every whip
configuration has been tested, a sufficient number of tests
have been made to permit the general observations that replacing
the standard whippers with a baffle-type whipper of this in-
vention results in a decrease in both viscosity and overrun of
oil-in-water emulsions with continuous product discharge from
the bowl appearing more uniform and product being more consis-
tently "scraped" from the bowl sides. Circulation is also
improved to a point where "dead" zones of underwhipped emulsion
are lessened.
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