U.S. patent application number 12/528622 was filed with the patent office on 2010-03-04 for continuous food product cooling system.
This patent application is currently assigned to BLENTECH CORPORATION. Invention is credited to Darrell C. Horn.
Application Number | 20100050656 12/528622 |
Document ID | / |
Family ID | 39721587 |
Filed Date | 2010-03-04 |
United States Patent
Application |
20100050656 |
Kind Code |
A1 |
Horn; Darrell C. |
March 4, 2010 |
CONTINUOUS FOOD PRODUCT COOLING SYSTEM
Abstract
A multi-stage continuous liquid chilling system for chilling
particulate food product with a chilling liquid. Particulate
product is conveyed through a rotating drum as vanes inside the
drum control and move the product from the inlet towards the
outlet. As the product is conveyed it is tumbled and mixed with the
chilling liquid in a succession of processing sections, each
including a flood portion and a drain portion. In both sections the
food product is exposed to a spray of chilled liquid, which Is
drained off and used in an earlier stage in the processing cycle.
While product is moved from the inlet to the outlet of the drum the
chilling liquid is pumped in the opposite direction with a series
of transfer pumps each connected to the drain sections in each
chilling zone.
Inventors: |
Horn; Darrell C.; (Santa
Rosa, CA) |
Correspondence
Address: |
STAINBROOK & STAINBROOK, LLP
412 AVIATION BOULEVARD, SUITE H
SANTA ROSA
CA
95403
US
|
Assignee: |
BLENTECH CORPORATION
ROHNERT PARK
CA
|
Family ID: |
39721587 |
Appl. No.: |
12/528622 |
Filed: |
February 26, 2008 |
PCT Filed: |
February 26, 2008 |
PCT NO: |
PCT/US2008/055026 |
371 Date: |
August 25, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60903617 |
Feb 26, 2007 |
|
|
|
Current U.S.
Class: |
62/1 ;
62/380 |
Current CPC
Class: |
F25D 25/04 20130101;
F25D 13/065 20130101; F25D 2400/28 20130101; A23L 3/361
20130101 |
Class at
Publication: |
62/1 ;
62/380 |
International
Class: |
F25D 31/00 20060101
F25D031/00; F25D 25/04 20060101 F25D025/04 |
Claims
1. A rotary drum chilling system for cooling particulate food
product, comprising: a generally cylindrical drum having an inlet
end, an outlet end, and a plurality of processing zones interposed
between said inlet end and said outlet end, including at least an
initial processing zone and a final processing zone, each of said
processing zones including a flood section, a drain section, and a
nozzle, wherein the downstream direction in said drum is from said
inlet end toward said outlet end and the upstream direction is from
outlet end toward said inlet end; at least one motor for rotating
said drum; a food conveyor disposed within said rotary drum for
moving food product in the downstream direction; a source of
chilling liquid in direct fluid communication with said nozzle in
said final processing zone; a final processing zone catch basin
disposed under said drain section of said final processing zone,
said catch basin in fluid communication with a processing zone in
the upstream direction; an initial processing zone catch basin
disposed under said drain section of said initial processing zone;
and a discharge conduit for discharging fluid from said initial
processing zone catch basin; wherein said nozzles discharge
chilling liquid so as to submerge food product in chilling liquid
in each of said flood sections for a period of time such that the
product particulates are surrounded with the chilled liquid,
exposes the coldest food product to the coldest chilling liquid in
said chilling system, agitates the food product as it is conveyed
through said processing zones, and wherein the movements of the
chilling liquid is controlled by said food conveyor such that
different temperatures of chilled liquid are not mixed together
during operation.
2. The system of claim 1, wherein said rotary drum is disposed
horizontally and is generally cylindrical.
3. The system of claim 2, wherein said food conveyor is a spiral
vane horizontally disposed within said rotary drum.
4. The system of claim 3, wherein said spiral vane is substantially
continuous and has a substantially constant angle.
5. The system of claim 4, wherein said system includes at least
three processing zones, including an initial processing zone, at
least one medial processing zone, and a final processing zone.
6. The system of claim 2, wherein said food conveyor comprises a
plurality of side-by-side vane elements, each of said vane elements
including an annular straight vane segment generally normal to the
longitudinal axis of said rotary drum and an angled vane segment
which connects said vane element with the straight vane portion of
the adjoining downstream vane element.
7. The system of claim 6, wherein said angled vane segment is
angled at approximately 45 degrees to said straight vane
segment.
8. The system of claim 1, wherein said system includes at least
three processing zones, including an initial processing zone, at
least one medial processing zone, and a final processing zone.
9. The system of claim 8, further including a catch basin disposed
under each of said medial processing zones, and a pipe, and a pump
for pumping chilling liquid to an upstream processing zone.
10. The system of claim 1, wherein said system includes at least
three processing zones, including an initial processing zone, at
least one medial processing zone, and a final processing zone.
11. The system of claim 10, further including a medial catch basin
disposed under each of said medial processing zones, and a pipe,
and a pump for pumping chilling liquid to a nozzle in an upstream
processing zone.
12. The system of claim 1, wherein said system is operatively
connected to a food cooker such that hot particulate food product
is received in said inlet end of said rotary drum, and wherein said
discharge conduit for discharging fluid from said initial
processing zone catch basin is in fluid communication with the food
cooker so as to provide makeup water for use in cooking food
product.
13. A method of chilling particulate food product, comprising the
steps of: (a) providing a multi-stage food chilling system as in
claim 1; (b) turning on the one or more motors driving the rotary
drum; (c) turning on the chilling system such that chilling liquid
is sprayed through nozzles in each of the processing zones; (d)
introducing cooked food product into the multi-stage chilling
system and continuing rotation of the rotary drum such that the
particulate food is flooded in the flood section of each processing
zone, drains completely in the drain section of each processing
zone.
14. The method of claim 13, further including the step of
discharging chilling liquid from the initial processing zone catch
basin for use as makeup water for a food cooker.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to commercial food
processing apparatus, and more particularly to food chilling
systems, and still more particularly to a multi-stage rotating drum
continuous liquid chilling system for particulate food
products.
[0003] 2. Background Art
[0004] At present the commercial market place includes numerous
continuous chilled liquid machines for chilling particulated food
products or diced products. All of the known systems utilize a
means of conveying food product and a means of causing heat
transfer by dousing the moving food product with a cold liquid. The
two predominant methods of conveying food product in chilling
systems included the perforated belt conveyor and the rotary
screened drum.
[0005] The perforated belt system allows the chilling liquid to
contact the food product on the belt as the product is conveyed
from an inlet end to an outlet end and then drains the chilling
liquid through perforations in the belt down into a catch pan under
the conveyor belt. The chilling liquid drained from the product
picks up some of the heat energy from the product thus cooling the
product to a lower temperature.
[0006] The disadvantage of a belt chiller is that the product is
static on the perforated belt and is not mixed with the chilling
liquid for efficient and optimal heat transfer. A second
disadvantage is that the layer of product on the belt is generally
not of uniform thickness so the chilling liquid that is sprayed
onto the product does not always penetrate through the thick layers
of product. A third disadvantage is that the chilled liquid is in
contact with the hot product for a very short time as it drains
through the hot product. This short contact time does not allow the
heat from the hot product to be transferred to the liquid
efficiently especially if the product comprises chunks of product
that require time for the heat in the center of the chunks to work
it way out to the surface of the chunks.
[0007] The final result of the perforated belt system is
inefficient utilization of the chilling liquid and warm areas left
in the layer of food product being chilled. This type of system
typically requires more chilled liquid to chill products.
[0008] Other chilling systems utilize a rotating drum screen with
spray nozzles spraying the chilling liquid down onto the hot
product as the product is conveyed through the inside of the
screened drum. Internal vanes convey the product as the screened
drum rotates. The chilling liquid mixes with hot product as the
screened drum rotates picking up heat energy from the product and
then drains through the screen into a catch pan under the drum.
[0009] The advantage of this system is that the hot product is
tumbled as the drum rotates and therefore all the pieces of product
are exposed to the spray of chilled liquid evenly transferring heat
from the product into the chilled liquid. The disadvantage is that
the contact time between the chilled liquid and the product as the
chilled liquid drains down through the hot product and through the
screened drum is also very short, and therefore there is little
time for the heat from the hot product to transfer to the chilled
liquid.
[0010] A second variation of the rotating drum system is to have
the drum solid so the chilling liquid does not drain through the
product but rather pools up and moves through the drum with the
product. This substantially increases the contact time between the
chilled liquid and the product allowing the maximum heat from the
product to be transferred into the liquid. The disadvantage is that
the chilled liquid moves with the product and warms up as it picks
up heat from the product. To efficiently chill a product and
minimize the amount of chilling liquid required, the coldest liquid
must be in contact with the coldest product. In other words, the
warmest chilling liquid should contact the warmest food product,
and the coolest chilling liquid should contact the coolest food
product. However, in this variation of the rotary drum the coldest
liquid is not in contact with the coldest product since the chilled
liquid moves through the rotary drum with the product.
[0011] A third variation of the rotating drum system is to position
the screened drum in a vessel filled with chilled water so that the
hot product is bathed in the chilled liquid. In this system the
product stays in contact with the chilled liquid for a longer
period so that the heat in the product can be efficiently
transferred to the chilled liquid. The hot product is tumbled
inside the rotating screened drum, thus mixing with the chilled
liquid evenly cooling the product.
[0012] The disadvantage of this system is that the movement of the
chilled liquid is not efficiently controlled, and therefore the
product being cooled is not always in contact with the coldest
chilled liquid as it progresses through the drum. As a result this
system takes more chilled liquid to cool the product and the energy
transfer from the product to the chilled liquid is not as efficient
as desired. Chilling the product to the desired temperature
requires a large amount of chilled liquid.
[0013] The foregoing prior art systems reflect the current state of
the art of which the present inventor is aware. Reference to, and
discussion of, these systems in such general terms is intended to
aid in discharging Applicant's acknowledged duty of candor in
disclosing information that may be relevant to the examination of
claims to the present invention. However, it is respectfully
submitted that none of the above-described prior art systems and
apparatus disclose, teach, suggest, show, or otherwise render
obvious, either singly or when considered in combination, the
invention described and claimed herein.
DISCLOSURE OF INVENTION
[0014] The present invention is a continuous liquid chilling system
for chilling diced or particulated food products such as diced
meat, vegetables or grains by contact with a cold liquid such as
cold water. As the particulated product is conveyed through the
rotating drum of the continuous rotary chiller the vanes inside the
drum control and move the product from the inlet towards the
outlet. As the product is conveyed it is tumbled and mixed with the
chilling liquid to transfer the heat from the product to the
chilled liquid. During the tumbling/conveying movement of the
product it is bathed in the chilled liquid in a first section and
then drained of the chilled liquid in the second section. In both
sections the product is exposed to a spray of chilled liquid. This
process of bathing the product in the chilled liquid and draining
off the chilled liquid is repeated multiple times in the length of
the drum to chill the product to the desired temperature. While the
product is moving from the inlet to the outlet of the drum the
chilling liquid is pumped or otherwise conveyed in the opposite
direction using a series of transfer pumps, gravity feed
structures, or the like, each connected to the drain sections in
each chilling zone. By moving the chilled liquid in the opposite
direction of the movement of the product, the coldest product is
exposed to the coldest chilling liquid to increase the efficiency
of heat transfer and reduce the amount of chilled liquid required
to reach the desired temperature of the product.
[0015] It is therefore an object of the present invention to
provide an improved commercial grade particulate food product
chilling system that allows time for heat transfer. The inventive
system mixes the product with the chilled liquid for sufficient
period of time to allow the heat energy to be drawn out of the
particulates that makeup the product. This heat energy must
efficiently transfer out of the product into the chilled
liquid.
[0016] It is another object of the present invention to provide a
multistage rotating drum chilling system that submerges the food
product in chilling liquid. The product is submerged in the chilled
liquid for a period of time such that the product particulates are
surrounded with the chilled liquid.
[0017] It is yet another object of the present invention to provide
a food chilling system apparatus that exposes the coldest product
to the coldest liquid. As the product is conveyed from inlet to
outlet of the machine the product must come in contact with colder
and colder chilled liquid, preferably in a succession of processing
zones. In other words the coldest chilled liquid must be introduced
into the system just before the product is discharged, and the
chilled liquid must be moved in the direction opposite the
direction of movement of the food product. Stated yet another way,
chilling liquid is moved upstream as the food product is moved
downstream through the processing zones.
[0018] Still another object of the present invention is to provide
an improved particulate food product chilling system that agitates
the food product as it moves through the chilling machine to make
sure that no hot spots are allowed to exist as the product is
chilled.
[0019] Yet another object of the present invention is to provide a
particulate food product chilling system that controls the product
and the chilled liquid movement. The movement of the chilled liquid
is controlled so that different temperatures of chilled liquid are
not mixed together in the process.
[0020] Other novel features which are characteristic of the
invention, as to organization and method of operation, together
with further objects and advantages thereof will be better
understood from the following description considered in connection
with the accompanying drawings, in which preferred embodiments of
the invention are illustrated by way of example. It is to be
expressly understood, however, that the drawings are for
illustration and description only and are not intended as a
definition of the limits of the invention. The various features of
novelty that characterize the invention are pointed out with
particularity in the claims annexed to and forming part of this
disclosure. The invention does not reside in any one of these
features taken alone, but rather in the particular combination of
all of its structures for the functions specified.
[0021] There has thus been broadly outlined the more important
features of the invention in order that the detailed description
thereof that follows may be better understood, and in order that
the present contribution to the art may be better appreciated.
There are, of course, additional features of the invention that
will be described hereinafter and which will form additional
subject matter of the claims appended hereto. Those skilled in the
art will appreciate that the conception upon which this disclosure
is based readily may be utilized as a basis for the designing of
other structures, methods and systems for carrying out the several
purposes of the present invention. It is important, therefore, that
the claims be regarded as including such equivalent constructions
insofar as they do not depart from the spirit and scope of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be better understood and objects other
than those set forth above will become apparent when consideration
is given to the following detailed description thereof. Such
description makes reference to the annexed drawings wherein:
[0023] FIG. 1 is a schematic cross-sectional side view in elevation
of the continuous food product chilling system of the present
invention;
[0024] FIG. 2 is an end view thereof, showing some apparatus in
phantom;
[0025] FIG. 3 is a cross-sectional side view in elevation showing
an alternative, discontinuous vane configuration for use in
segregating flood and drain sections and for conveying food product
through the rotary drum taken along section line 3-3 of FIG. 4;
and
[0026] FIG. 4 is an end view of a single element of the vane
elements of FIG. 3.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Referring to FIGS. 1 through 4, wherein like reference
numerals refer to like components in the various views, there is
illustrated therein a new and improved continuous particulate food
product chilling system, generally denominated 100 herein. These
views, collectively, show that the inventive system first includes
a generally cylindrical multi-stage rotating drum 110 with three or
more processing zones, including an initial processing zone 120,
one or more medial processing zones, 130, and a final processing
zone 140, each including an impermeable solid stainless steel flood
section 120a, 130a, 140a, and a perforated drain section 120b,
130b, 140b. The drum in each of the perforated drain sections is
provided with a band of holes circumferentially disposed around the
entirety of the drum. One or more motors 115 for rotating the drum
are disposed on mounts 117 attached to the support frame 119 for
the chilling system.
[0028] The drum further includes an inlet end 150, where cooked
food product is received after conveyance from a cooker 160, and an
outlet (discharge) end 170, where chilled food product is
discharged. In a cooker ideally adapted for use with the chilling
system of the present invention, cooked food product is conveyed
from the cooker through a conduit 180 having perforations 190 or a
channel for draining hot cook water 200 into a tank or catch basin
210. That water may then be reclaimed and recycled by pumping or
conveying it directly to the cooker for use in the current cooking
cycle or first processed and cleaned for use in a subsequent
cooking cycle.
[0029] The solid stainless steel flood sections 120a, 130a, 140a
are where food product is flooded or submerged in the chilled
liquid so that the product particulates are surrounded with the
chilled liquid. This provides for thorough heat transfer because
all of the surfaces of the product particulates have contact with
the chilled liquid. In addition, the particulates remain submerged
in the liquid for a sufficiently long period of time such that the
heat inside of the particulates is drawn out to the surface and
transferred into the chilled liquid. In this section, heat transfer
time and submersion of the food product is accomplished.
[0030] The perforated drain sections 120b, 130b, 140b are where
chilled liquid is drained out and away from the product so that
colder chilled liquid will be in contact with the product without
being diluted with the upstream cooling liquid that has absorbed
heat energy from the product in the solid steel submerged
section.
[0031] Referring now to FIG. 1, the two sections in each zone are
separated by a horizontally disposed and substantially continuous
spiral barrier or spiral vane 220 depending from the sides of the
rotary drum and running substantially the entire length of the
cylindrical drum, i.e., from the food product inlet end 150 to the
food product outlet end 170. The continuous flights of the spiral
vane rotate with the drum, such that as the cylindrical drum
rotates, the food product is tumbled and urged against the flights
of the spiral vane and is thus constantly pushed from the inlet of
the rotary chiller toward the outlet. In the configuration shown,
four full rotations of the drum conveys the food product through
one of the processing zones. Further rotations conveys the food
product sequentially through each of the solid stainless steel
submersion sections and the perforated drain sections of the entire
system. The spiral vane thus provides the necessary control over
the ultimate chilling system.
[0032] The rotation of the drum also causes the product to be
tumbled and agitated. The tumbling action mixes the product with
the chilled liquid in the submersion sections and then equilibrates
the product in the drain sections.
[0033] Next, the inventive apparatus includes a multi-stage chilled
liquid circulation system which includes a source of refrigerated
fluid (not shown) for providing a chilling fluid which is pumped by
a first chilling system pump 230 through a pipe 240 having a first
nozzle 250 disposed at its end in the upper portion of the final
processing zone 140. It will be understood that the discussion of
pumps as the means for conveying chilling liquid from the
downstream zones to the upstream processing zones is for
illustrative purposes only, as such a process may be effected by
other fluid conveyance means, including the use of gravity feed
apparatus, water screws or vanes, ram pumps, high lifter pumps, and
so on. After conveyance upstream, the chilled liquid is sprayed or
otherwise discharged or poured into the flood section to cover the
particulate food product immediately before it is discharged.
[0034] A final processing zone catch basin 260 disposed immediately
below the final perforated section 140b captures chilling liquid
drained from the final processing zone 140. The fluid captured by
the final processing zone catch basin is then pumped by a second
chilling system pump 270 through pipes 280 to a second nozzle 290
disposed in the second processing zone 130, where it is sprayed
over food product in that zone. Pipe 280 enters into the drum
through either the discharge end or the inlet end, and in the case
of the former it runs in a generally side-by-side relationship to
pipe 240 for the length of that latter pipe. In the event there are
more than one medial processing zones, catch basins, pumps and
pipes, and nozzles are also provided for each such additional
processing zone.
[0035] A medial catch basin 300 disposed immediately below the
perforated section 130b of the second (medial) processing zone 130
captures chilling liquid drained from that processing zone. The
captured fluid is then pumped by a third pump 310 through a pipe
320 to a third (final) nozzle 330 disposed in the initial
processing zone 120, where it is sprayed over or otherwise poured
or discharged into the flood portion to cover the food product in
that zone. Pipe 320 also enters into the drum either through the
discharge end or the inlet end, and when the latter it runs in a
generally side-by-side relationship to pipes 240 and 280 for the
respective lengths of those two pipes. It will be appreciated by
those with skill in the art that one or more of pipes 240, 280, and
320, and in any combination, may enter the drum through one or the
other or both the inlet and outlet ends without any effect on
system function.
[0036] Chilling liquid drained from the first processing zone is
captured by third catch basin 340, and is fed through a discharge
conduit of some kind, preferably a pipe 350, and is transported
either by gravity or by a pump (not shown) to a predetermined
discharge destination. The warmed chilling liquid may simply be
discarded, though because of the waste involved in such a
treatment, it would be preferable to use the liquid, and when water
is the coolant liquid, the final disposition is preferably
transport to the cooker tank 210 for recycling drained cook water
by using it in the cooking process in the cooker 160.
[0037] FIG. 3 is a cross-sectional side view in elevation showing
an alternative, discontinuous vane configuration 400 for use in
segregating flood and drain sections and for conveying food product
through the rotary drum, while FIG. 4 is an end view of a single
vane element 410 of the vane system shown in FIG. 3. In this
configuration, the vane system, rather than comprising a continuous
helical spiral vane having a substantially constant angle,
comprises a plurality of vane elements 410, each including an
annular first straight vane segment 420a, which is substantially
normal to the longitudinal axis 430 of the rotary drum 440. This
first segment extends approximately 270 to 320 degrees of arc,
though dimensions of more or less arc would be acceptable. A second
angled vane segment 420b angles downstream at an approximate 45
degree angle, though angles from 20 degrees to 60 degrees may be
suitable, depending on the length of time called for in chilling
food product in the flood portions of the processing zones. This
will be affected by the spacing of the vanes, the volume of the
drum space between vanes, the rapidity of rotation of the drum, and
so on. The final vane segment 420c is contiguous with the first
straight vane segment of the neighboring downstream vane
element.
[0038] Using this alternative vane configuration, food product
migrates downstream through a processing zone every six full
revolutions. While in the flood portion of the processing zones,
food product does not migrate laterally and downstream until
engaged by angled segment 420b. This facilitates full immersion and
a thorough transfer of heat from the food product to the chilling
liquid.
[0039] From the foregoing it will be apparent that chilled liquid
coming directly from the refrigeration machine enters the rotary
chiller through spray nozzles in the final processing zone and
picks up some of the heat energy from the product being tumbled
through that zone. When water drained from the final processing
zone is pumped upstream and through the spray nozzles in the medial
processing zone(s), it picks up more heat energy from the warmer
product being tumbled through those processing zones. Finally, the
chilled liquid is pumped upstream yet again and sprayed through a
nozzle in the initial processing zone, where it is warmed by
absorbing heat energy from the product being tumbled through the
initial processing zone; it is then drained into the catch basin
under the initial processing zone and is already preheated for use
as makeup water in the cooking machine upstream.
[0040] The movement of the chilled liquid upstream results in the
coldest liquid always coming in contact with the coldest product as
the product is conveyed through the rotary chilling system. This
water recycling method minimizes the use of chilled water in the
process, thereby chilling the product faster and ultimately to a
colder temperature. At the same time the heated water is reused as
makeup water in the cooker if the process has a cooker upstream of
the rotary chiller.
[0041] In a four processing zone chilling system using the
inventive multi-stage cooling system, chilled liquid is sprayed on
the food product in a fourth processing zone, captured under the
rotating drum, then pumped through nozzles in the third processing
zone, captured again the rotating drum in the third zone, then
pumped through nozzles in the upstream second processing zone and
finally captured under the second processing zone and pumped
through nozzles in the first processing zone. In a four processing
zone system, by spraying 2-3 degree C. chilled water on the fourth
processing zone, the product can be chilled from 95 degrees C. down
to 5 degrees C. while the chilled water absorbs the heat from the
product and is heated up to about 60 degrees C. by the time it has
been recycled through the hot product entering the inlet end into
the first processing zone of the chilling conveyor drum.
[0042] The above disclosure is sufficient to enable one of ordinary
skill in the art to practice the invention, and provides the best
mode of practicing the invention presently contemplated by the
inventor. While there is provided herein a full and complete
disclosure of the preferred embodiments of this invention, it is
not desired to limit the invention to the exact construction,
dimensional relationships, and operation shown and described.
Various modifications, alternative constructions, changes and
equivalents will readily occur to those skilled in the art and may
be employed, as suitable, without departing from the true spirit
and scope of the invention. Such changes might involve alternative
materials, components, structural arrangements, sizes, shapes,
forms, functions, operational features or the like.
[0043] Therefore, the above description and illustrations should
not be construed as limiting the scope of the invention, which is
defined by the appended claims.
* * * * *