Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
Method and Apparatus for Combining Particulate and Soft-Serve Ice Cream
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No.
601700,253, which was filed on July 18, 2005.
FIELD OF THE INVENTION
[0002] The present invention relates to ice cream and more particularly to an
apparatus and method for combining particulate and soft-serve conventional ice
cream.
BACKGROUND OF THE INVENTION
[0003] Soft-serve ice cream has existed for many years in many embodiments.
Particulate ice cream is newer and not as ubiquitous in the marketplace.
However,
attempts to combine the two have been rare because the process of making soft-
serve ice cream differs substantially from making particulate ice cream.
Consequently, a method and apparatus for combining the two entities is
desired.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide an apparatus and
method
for combining soft-serve and particulate ice cream, comprising a cryogenic
processor, for use in producing particulate ice cream beads; a mechanism for
producing soft-serve ice cream which uses purified N2; and a blending means.
It is
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another object of the present invention to provide a variable speed fruit and
nut
feeder, for managing and measurably dispersing the beads at a suitable rate
for
combination with the soft-serve ice cream, and an ingredient feeder, also for
combining the beads with the soft-serve ice cream.
[0005] These and other objects of the invention will become readily apparent
as
the following description is read in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Fig. 1 shows a portion of the present invention;
[0007] Fig. 2 shows another portion of the present invention; and
[0008] Fig. 3 shows yet another portion of the present invention.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] Before explaining the disclosed embodiment of the present invention in
detail it is to be understood that the invention is not limited in its
application to the
details of the particular arrangement shown, since the invention is capable of
other
embodiments. Also, the terminology used herein is for the purpose of
description
and not of limitation.
[00010] Fig. 1 shows a cryogenic processor constructed in accordance with the
preferred embodiment of the present invention to produce free-flowing beads
56.
The fundamental method utilized to produce the product is described in detail
in U.S.
Pat. No. 5,126,156, which is hereby incorporated by reference.
[00011] A cryogenic processor 10 includes a freezing chamber 12 that is most
preferably in the form of a conical tank that holds a liquid refrigerant
therein. A
freezing chamber 12 incorporates an inner shell 14 and an outer shell 16.
Insulation
18 is disposed between the inner shell 14 and outer shell 16 in order to
increase the
thermal efficiency of the chamber 12. Vents 20 are also provided to ventilate
the
insulated area formed between the shells 14 and 16. The freezing chamber 12 is
a
free-standing unit supported by legs 22.
[00012] A refrigerant 24, preferably liquid nitrogen, enters the freezing
chamber 12
by means of refrigerant inlet 26. The refrigerant 24 is introduced into a
chamber 12
through the inlet 26 in order to maintain a predetermined level of liquid
refrigerant in
the freezing chamber because some refrigerant 24 can be lost by evaporation or
by
other means incidental to production. Gaseous refrigerant that has evaporated
from
the surface of the liquid refrigerant 24 in freezing chamber 12 primarily
vents to the
atmosphere through exit port 29 which cooperates with the vacuum assembly 30,
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which can be in the form of a venturi nozzle. Extraction of the frozen beads
occurs
through product outlet 32 adapted at the base of the freezing chamber 12.
[00013] An ambient air inlet port 28 with adjustment doors 38 and exit port 29
with
adjustment doors 39 are provided to adjust the level of gaseous refrigerant
which
evaporates from the surface of the liquid refrigerant 24 so that excessive
pressure is
not built up within the processor 10 and freezing of the liquid composition in
the feed
assembly 40 does not occur.
[00014] A feed tray 48 receives liquid composition from a delivery source 50.
Typically, a pump (not shown) drives the liquid composition through a delivery
tube
52 into the feed tray 48. A premixing device 54 allows several compositions,
not all
of which must be liquid, such as powdered flavorings or other additives of a
size
small enough not to cause clogging in the feed assembly 40, to be mixed in
predetermined concentrations for delivery to the feed tray 48.
[00015] In order to create uniformly sized particulate beads 56 of frozen
product,
uniformly sized droplets 58 of liquid composition are required to be fed
through gas
diffusion chamber 46 to freezing chamber 12. However, the present invention
can
also produce non-uniformly sized chunks of particulate ice cream, and should
not be
considered as limited exclusively to beads. The feed tray 48 is designed with
feed
assembly 40 that forms droplets 58 of the desired character, which could
include
shapes other than beads. The frozen product takes the form of beads or chunks
that
are formed when the droplets 58 of liquid composition contact the refrigerant
vapor in
the gas diffusion chamber 46, and subsequently the liquid refrigerant 24 in
the
freezing chamber 12. After the beads or chunks 56 are formed, they fall or are
mechanically directed to the bottom of chamber 12. A transport system connects
to
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the bottom of chamber 12 at outlet 32 to carry the beads or chunks 56 of
particulate
ice cream to a packaging and distribution network for later delivery and
consumption.
[00016] The vacuum assembly 30 cooperates with air inlet 28 and adjustment
doors 38 so that ambient air flows through the inlet and around feed assembly
40 to
ensure that no liquid composition freezes therein. This is accomplished by
mounting
the vacuum assembly 30 and air inlet 28 on opposing sides of the gas diffusion
chamber 46 such that the incoming ambient air drawn by the vacuum assembly 30
is
aligned with the feed assembly. In this configuration, ambient air flows
around the
feed assembly warming it to a sufficient temperature to inhibit the formation
of frozen
liquid composition in the feed assembly flow channels. An air source 60,
typically in
the form of an air compressor, is attached to vacuum assembly 30 to provide
appropriate suction to create the ambient air flow required.
[00017] It has been long established practice that when making soft-serve ice
cream, the ice cream must be held in a freezing cold "hardening cabinet" for
2, 4, or
maybe 8 hours prior to shipping or delivery. However, because the beads or
chunks
56 of particulate ice cream of the present invention are frozen at
substantially lower
temperatures than soft-serve ice cream, such as -180F, the interspersing of
the
ultra-cold particulate within the soft-serve negates or greatly reduces this
requirement.
[00018] Fig. 2 shows an exemplary apparatus for blending particulate and soft-
serve ice cream into a blended mix. In Fig. 2, the beads 56 are fed into an
ingredient
feeder such as a variable speed fruit and/or nut feeder 204 either directly
from the
outlet 32 or from a transport mechanism. In either case, the beads 56 are
combined
with the semi-frozen soft ice cream from a barrel freezer by a stuffing pump
208,
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which forces the combination through a static mixer 212 where it is blended
and then
output into a container 220 either for consumption, shipping, or a hardening
cabinet.
The container can be either a bowl, a pint cup, or quart container, or perhaps
some
other type of vessel.
[00019] The stuffing pump ensures that a pre-configurable percentage of beads
56
are inserted into the soft-serve soft ice cream, yet regulates the pressure
and flow
such that the beads 56 are not crushed. In an exemplary embodiment, the
stuffing
pump 208 feeds back information to a central control device 240 which can
automatically make real-time adjustments to both the variable speed fruit and
nut
feeder 204 as well as a mechanism which controls the flow of soft-serve ice
cream
from the barrel freezer. An operator may also use the central control device
240 to
make manual adjustments.
[00020] As shown in Fig. 2, the central control device 240 may be located at a
standard room temperature environment separate from the food-preparation
environment, and information communicated thereto could be wirelessly or
remotely
transmitted to the stuffing pump or ingredient feeder 208 and other mechanisms
via
communication means such as but not limited to WiFi or Bluetooth.
[00021] The combination of pump or feeder 208 and mixer 212 can include a
lamella pump, but an embodiment also exists in which a specialized screw auger
feeds the beads 56 and moves the finished combined product to the package 220.
This embodiment incorporates a dosing screw to induce the proper amount of
beads
56, and a traveling screw that will move the blended product to the package
220 at a
higher pressure than standard ice cream pumps. All the above items are
carefully
calibrated to not crush the beads or chunks 56 during the blending process.
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[00022] To ensure maximum coldness, the beads or chunks 56 of particulate ice
cream can be stored or dipped in LN2 prior to introduction into the feeder 208
and
mixer 212. This has the effect of ensuring that the beads or chunks 56 stay
below a
temperature of -180 F, which is useful when being combined with the soft-serve
ice
cream which will be discussed in more detail below.
[00023] As shown in Fig. 3, the soft-serve ice cream of the present invention
can
be manufactured using an arrangement 300 of cryogenic equipment including a
phase converter 312 in line with a compressor 316. The phase converter 312
receives liquid N2 (LN2) from an LN2 source 304 and outputs N2 vapor having
absolutely no LN2 therein. The purity level of the LN2 inside the source 304
is
99.998% N2. However, N2 vapor has significantly less moisture, impurities, and
humidity than LN2. Consequently, the N2 vapor delivered to the compressor 316
is
extremely unlikely to introduce impurities into the resulting ice cream. Also,
because
no moisture or humidity is present at the N2, the likelihood of the air
brought into the
barrel freezer 324 forming ice crystals is reduced.
[00024] A pressure relief valve 308 is located between the LN2 source 304 and
the
phase converter 312, for the purpose of stepping down the pressure from the
LN2
source prior to entry into the phase converter 312. Because of its extreme low
temperature (-320 F) and extreme high pressure (38-44 PSI) inside the LN2
source,
the N2 emitted therefrom will naturally revert to a vapor state as soon as it
comes in
contact with normal ambient temperatures and regular atmospheric pressures,
such
as while inside the phase converter 312. Reducing pressure from the LN2 source
304 before reaching the phase converter 312 has the advantage of ensuring that
none of the N2 vapor that reaches the compressor 316 has any chance of
returning
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to a liquid stage. Accordingly, no additional or artificial pressure is needed
to
accelerate the transformation from liquid to vapor.
[00025] The phase converter 312 has a series of fins, baffles, or manifolds so
that
its interior contents can have as much (controlled and contained) exposure as
possible to normal non-cryogenic room temperatures. The phase converter also
takes advantage of the natural tendency of N2 vapor to rise as it is warmed.
Specifically, as shown in Fig. 3, the LN2 enters at the bottom of phase
converter
312, while the N2 vapor exits at the top.
[00026] Also as shown in Fig. 3, a heat wrap is located at the outlet of the
phase
converter 312 to bring the temperature of the N2 vapor to approximately +65 F.
This
heat wrap ensures temperature stability of the purified N2 vapor being fed
into the
compressor 316. Many compressors do not have the capability of handling
cryogenic temperatures such as -180F, although the present invention further
comprises a specialized compressor suitable for cryogenic temperatures, as
will be
discussed below. The N2 vapor is restored to +65 F and then directed into the
input
of a compressor 316, which in turn operates a barrel freezer 324 through a
secured
(private) line 320. The private line 320 is specially sealed to prevent any
possibility
of leakage or introduction of outside elements into the N2 vapor. Such private
routing has the advantage of avoiding the introduction of outside moisture.
[00027] An additional feature of the present invention is its ability to
reduce the
formation of ice crystals, and also reduce the sizes of those that do form.
Large ice
crystals dilute the taste and quality of the resulting ice cream. The colder
the soft-
serve ice cream is kept in the manufacturing, the less likely it will be to
form ice
crystals from the moisture that is in normal air, or the ice cream mix itself
containing
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some water. The present invention reduces this problem by adding the beads and
chunks 56 of particulate ice cream to the soft-serve ice cream while the beads
are at
approximately -180 F or colder, which renders the resulting blended product
(Fig. 2)
into a much colder temperature, such as 0 F and below, than the temperature at
which the soft-serve ice cream is output from the barrel freezer 324. These
colder
temperatures, such as 0 F and below, can reduce and sometimes entirely
eliminate
the formation of unwanted ice crystals.
[00028] In an alternate embodiment, trace amounts of non-heated N2 directly
from
the LN2 source are introduced directly into the barrel freezer, without being
compressed. The amount of N2 is carefully calibrated or metered so as to
achieve a
specific overrun (percentage of air within the finished ice cream product).
This
modification saves the barrel freezer from having to do as much work in
cooling the
ice cream to the desired temperatures.
[00029] In an additional alternate embodiment, a specialized compressor is
used
which, as stated, has the ability to withstand cryogenic temperatures input
thereto.
This compressor routes N2 vapor directly into the barrel freezer 324 at
cryogenic
temperatures (in controlled dosages), so that the barrel freezer 324 is able
to
achieve a desired overrun. This embodiment also saves the barrel freezer from
having to do as much work in cooling the ice cream to the desired
temperatures.
[00030] Within the present invention, a screw compressor 316 is employed in
conjunction with the barrel freezer 324, rather than a reciprocating
compressor.
Although reciprocating compressors are commonly used in ice cream production,
they can introduce a minute amount of oil into the coolant that is being
compressed.
With the reciprocating compressor, this oil could conceivably make its way
into the
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ice cream products, albeit in trace amounts that are well below health and
purity
safety limits. Nonetheless, even a trace amount of oil in an ice cream product
could
affect its taste. Conversely, screw compressors require 20-30% less oil than a
reciprocating compressor. Thus, substituting a screw compressor for a
reciprocating
compressor reduces this problem.
[00031] The screw compressor 316 of the present invention is made so the
screws
are pressurized so any oil that is present in oil journals will be pushed away
from the
stream of air being compressed, and not sucked inward. The screw compressor
316
has a first combination oil separator/compressor system that eliminates any
remaining oil from the air stream. Additionally, the screw compressor 316 also
has a
pressure tank for storage and additional oil (second) separation. Any oil that
may
get past the built-in (first) separator will be deposited into the bottom of
the pressure
tank and will be discharged entirely. Meanwhile, the system-usable N2 is
discharged
from the top of the pressure tank. There is an additional (third) oil
separator after the
pressure tank, that should any oil be present, will also be discharged.
Finally, there
is also a (fourth) oil separator in the barrel freezer (not shown), which is a
bowl-
shaped device.
[00032] The N2 is discharged from the compressor and directed to the side of
the
tank so that any oil or moisture will come in direct contacts therewith.
Accordingly,
oil will stay on the side of the tank, then travel to the bottom of the tank.
An opening
at the bottom of the tank allows the collected oil to enter a float chamber,
external to
the tank. When the chamber is filled, a float device raises to activate a
switch, a
solenoid is opened and the N2 pressure in the tank drives the oil out of the
chamber.
When the level in the chamber is lowered, the float device drops and the
switch is
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deactivated, the solenoid closes and the process starts all over again. The
pressurized N2 thus rises to the top opening in an "oil free" state, and
enters the
private line to the barrel machine 324.
[00033] The various aspects of the present invention has been described in
detail
with particular reference to preferred embodiments thereof, but it will be
understood
that variations and modifications can be effected within the spirit and scope
of the
invention as described herein. It is anticipated that various changes may be
made in
the arrangement and operation of the system of the present invention without
departing from the spirit and scope of the invention, as defined by the
following
claims.
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