Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR EXPOSING
COMMINUTED FOODSTUFF TO A PROCESSING FLUID
TECHNICAL FIELD OF THE INVENTION
The invention relates to foodstuff processing and, more particularly, to an
apparatus
and method for exposing comminuted foodstuffs to a processing fluid such as
ammonia gas
or aqueous ammonia.
BACKGROUND OF THE INVENTION
Certain food processing operations require adding processing fluids to a
foodstuff.
U.S. Patent No. 5,871,795, for example, discloses a method using ammonia
and/or carbon
dioxide to modify the pH of a meat product. The treatment disclosed in U.S.
Patent No.
5,871,795 has been shown to decrease pathogenic microbe content in meat
products. U.S.
Patent No. 6,389,838 also discloses a process in which a pH modifying material
such as
gaseous or aqueous ammonia is applied to meat products as part of an overall
process that
includes freezing and physically manipulating the pH modified meat product.
Treatment processes that expose foodstuffs to a processing fluid may require a
controlled and consistent application of the processing fluid. Depending upon
the
treatment process, underexposure may not provide the desired results, while
overexposure
to the processing fluid may produce undesirable results. In the pH adjustment
processes
described in U.S. Patent Nos. 5,871,795 and 6,389,838 for example, portions of
the meat
product being treated may be overexposed to the pH adjusting fluid while other
portions of
the meat product may be exposed to very little or none of the pH adjusting
fluid. The
overexposed portions may absorb sufficient adjusting fluid to affect the taste
of the treated
?5 product and to produce a residual pH adjusting material odor. Underexposed
portions of
the meat product may not exhibit the desired pathogenic microbe inhibiting
effect.
SUMMARY OF THE INVENTION
A contactor or sparger apparatus according to the present invention is adapted
to
expose a cornminuted foodstuff such as comminuted meat to a processing fluid
such as
gaseous or aqueous ammonia or carbon dioxide gas. The apparatus facilitates an
even and
consistent exposure to the processing fluid throughout the comminuted
foodstuff as the
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foodstuff is pumped through a conduit. In order to produce this desired
exposure to the
processing fluid, the apparatus shapes the comminuted foodstuff into a
relatively thin sheet
or stream of material flowing through a contact passage. The processing fluid
is then
applied to this relatively thin sheet or stream of comminuted material from a
processing
fluid chamber located adjacent to the contact passage. A fluid communication
arrangement
between the fluid chamber and the contact passage allows the flow of
processing fluid into
the contact passage and into contact with the sheet or stream of foodstuff
flowing through
the contact passage.
The contactor apparatus may use various structures to shape the comminuted
foodstuff into the desired thin sheet of material. In one preferred form of
the apparatus, the
contact passage is defined between two substantially parallel and planar
contact passage
walls which force the comminuted foodstuff into a thin planar sheet of
material as it flows
through the contactor apparatus. In other embodiments of the invention, the
contact
passage comprises a narrow cylindrical or other appropriately shaped tube. In
this form of
the invention, a number of tubes may run parallel to each other to provide the
desired
overall flow area.
One preferred form of the apparatus includes a contactor body having an inlet
end
adapted to receive comminuted foodstuff and an outlet end for passing the
comminuted
foodstuff on to further processing equipment after the foodstuff has been
exposed to the
processing fluid. The contact passage is located between the contactor body
inlet end and
outlet end. A portion of the contactor body inlet generally transitions down
from inlet flow
dimensions to the dimensions required to produce the desired thin sheet of
material in the
contact passage. A portion of the contactor body outlet similarly transitions
baclc from the
dimensions of the contact passage to the outlet dimensions that are not
restricted by the
dimensions of the desired thin sheet of material.
The method of the invention includes forming or producing the flowing sheet of
comminuted foodstuff and then exposing the flowing sheet of material to the
processing
fluid in at least one of the major surfaces of the sheet. In the preferred
form of the
invention, the transverse dimension of the flowing sheet of material is
generally equal to a
dimension of the foodstuff pieces making up the cormninuted foodstuff. The
processing
fluid may enter the sheet of material through one or both of the opposing
surfaces used to
form the sheet.
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Alternatively to forming a sheet of foodstuff, the method may include forming
a
number of narrow streams of foodstuff. This form of the invention includes
exposing the
foodstuff in the narrow streams to the processing fluid through the walls of
the structures
forming the narrow streams.
The invention is particularly suited for comminuted foodstuffs such as meat or
meat
products, including beef, pork, lamb, and other red meats. The comminuted
foodstuff may
also include or be made up of poultry or sea foods. Comminuted foodstuffs that
may be
treated according to the present method may also include various additives or
fillers. As
used in this disclosure and the following claims, a "comninuted" material
comprises
generally a material that has been cut into relatively smaller pieces from one
or more
relatively larger pieces. The meat product being treated may be originally
comminuted by
any suitable device such as grinder or bowl chopper, or by manual trimming or
cutting.
Some forms of the invention may also incorporate a grinding element for
comminuting the
foodstuff as it enters the process fluid contacting passage or passages.
A sparging device within the scope of the present invention may be configured
with
two or more separate fluid chambers defined in the sparger body. Each separate
fluid
chamber may include a separate fluid cormnunication device with each sparger
passage.
The different fluid chambers may be used to add different processing fluids to
the foodstuff
as it flows through the sparger passages. Including multiple fluid chambers in
the sparging
device according to the invention allows different processing fluids to be
quiclcly and
efficiently added to the foodstuff in rapid succession.
These and other advantages and features of the invention will be apparent from
the
following description of the preferred embodiments, considered along with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a somewhat diagrammatic side view of a treatment system
incorporating
a contactor apparatus embodying the principles of the invention, partially
broken away to
show the interior of the contactor apparatus.
Figure 2 is a view in perspective of a contactor apparatus embodying the
principles
of the invention.
Figure 3 is a view in section taken along line 3-3 in Figure 2.
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Figure 4 is an enlarged view in section showing a portion of the insert in
Figure 3.
Figure 5 is a right end view of the alternate contactor apparatus shown in
Figure 2.
Figure 6 is a view in section similar to Figure 3, but showing an alternate
fluid
communication arrangement according to the invention.
Figure 7 is a right end view of a sparging screen embodying the principles of
the
invention.
Figure 8 is a section view taken along line 8-8 in Figure 7.
Figure 9 is a right end view of a sparging device embodying the principles of
the
invention having a multiple stage sparging screen.
Figure 10 is a longitudinal section view tal~en along line 10-10 in Figure 9.
DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 illustrates one preferred form of treatment system 10 employing a
contactor or sparger device 15 embodying the principles of the invention.
Treatment
system 10 includes an initial comminuting device 11 and a further comminuting
device 12.
Also, treatment system 10 includes a metering device 14 for directing the
foodstuff through
contactor apparatus 15.
Both of the comminuting devices 11 and 12 in this treatment system comprise
grinders such as the Model No. 1109 grinder by Weiler & Company, Inc. Grinder
11
receives relatively large pieces of foodstuff such as meat product 20 and
produces an initial
or original comminuted meat product 21. The grinder plate associated with
grinder 11 may
include openings having a maximum dimension preferably between approximately
two (2)
inches and three-eighths (3/8) of an inch. hl a more preferred form of the
system, the
grinder plate openings in grinder 11 have a maximum dimension of between one-
half (%2)
of an inch to three-eighths (3/8) of an inch. The maximum dimension of the
openings in
the grinder plate generally determines the maximum dimension of the
cornminuted material
exiting the grinder.
It will be appreciated that the original comminuted product 21 exiting grinder
11 is
made up of a plurality of discrete pieces arranged together in a continuous
mass.
Individual pieces are represented in the drawings at reference numeral 25.
Since these
individual pieces are mixed together with other discrete pieces, they are not
necessarily
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visible individually from the collective mass of material. However, the
discrete pieces 25
are shown for purposes of explaiiung the operation of the invention.
In treatment system 10, grinder 12 receives the original cormninuted meat
product
after the material has been exposed to a processing fluid such as gaseous or
aqueous
ammonia in the contactor apparatus 15. Grinder 12 further comminutes the
original
comminuted material and may include a grinder plate having openings smaller
than the
openings in the grinder plate associated with grinder 11. For example, grinder
12 may
include a grinder plate having openings with a maximum dimension of no greater
than
three-sixteenths (3/16) of an inch and preferably about one-eighth (1/8) of an
inch.
Alternatively, the grinder plate associated with grinder 12 may have the same
size openings
as grinder 11 and still perform some comminuting. W any event, the further
comminuted
material 22 exits grinder 12 and is collected for packaging or for transport
to further
processing equipment. Figure 1 shows the further comminuted material 22 being
collected
in a receiving tub 23.
In the treatment system 10 shown in Figure 1, metering device 14 comprises a
suitable positive displacement metering device. Metering device 14 receives
the
comminuted foodstuff 21 in collection chute 27 and then meters the comminuted
foodstuff
through processing fluid contactor 15 as indicated by the flow direction shown
at arrow F.
Other forms of the treatment system may use other means for forcing the
comminuted
foodstuff into and through contactor 15. The particular metering or pumping
device will
include a motor for driving the device with sufficient power to force the
comminuted
foodstuff through contactor 15 and the conduits leading to and from the
contactor.
The treatment process performed by system 10 and the operation of contactor 15
may now be described with reference to Figures 1 through 3. Referring to
Figure 1, meat
20 is ground or otherwise comminuted to form the original comminuted meat
product 21.
This comminuted meat product is collected in metering device chute 27 and
forced by
metering device 14 through processing fluid contactor 15. W processing fluid
contactor 15,
at least a portion of the comminuted meat product 21 is exposed to the
processing fluid
such as aqueous or gaseous ammonia. The meat product passes from contactor 15
to
grinder 12 where the material is preferably further comminuted. The further
comminuted
meat product 22 is expelled from device 12 and collected for packaging or for
further
processing.
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The foodstuffs may be processed according to the invention in a wide
temperature
range. For example, meat may be maintained at a temperature above 32 °F
for both the
process fluid contacting step and the further comminuting step. In any event,
the meat
product temperature should be high enough that some liquid component remains
in the
meat product during the further comminuting step.
Figures 2 through 6 show one preferred type of contactor or sparger device
that may
be employed as the device diagrarmatically shown at reference numeral 15 in
Figure 1.
The perspective view of Figure 2 shows the general structure of a contactor
device 40
while Figures 3 and 6 show two fluid communication variations within this
general
structure. The end view shown in Figure 5 is substantially identical in both
alternate forms
of invention shown in Figures 3 and 6.
Contactor 40 includes generally a contactor body formed by two components 41
and 42 and includes a foodstuff flow passage fiom a first end of the contactor
body to a
second end. The foodstuff flow passage in this form of the invention includes
a first end or
inlet end portion shown generally at reference numeral 44 and a second end or
outlet end
portion shown generally at reference numeral 45. These end portions 44 and 45
of the
foodstuff flow passage are separated by a contact passage shown generally at
reference
numeral 46. As shown best in Figures 3 and 6, contact passage 46 is actually
formed
through a separate insert mounted within the contactor body. This insert is
shov~m at
reference numeral 48 in Figure 3, and 48' in Figure 6. The fluid communication
arrangement in this fonn of the invention is associated with this insert as
will be described
further below. In both alternatives of the invention shown in Figures 3 and 6,
a processing
fluid chamber 49 is included in the contactor body. Processing fluid chamber
49 comprises
an ammlar area encompassing the respective insert 48 or 48', and the insert
separates fluid
chamber 49 from contact passage 46.
The two end components 41 and 42 are flanged together with a flange comiection
shown generally at reference numeral 51. The illustrated form of contactor 40
also
includes a flange 52 at one end for connecting the device to a suitable
conduit, and a
threaded connector 53 at the opposite end for connecting the opposite end to a
suitable
conduit. Although flange and threaded connectors are shown in the illustrated
embodiment, it will be appreciated that the invention is by no means limited
to these types
of connectors. Also, although the two-piece arrangement (components 41 and 42)
shown
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in the figures is preferred for its durability, ease of construction, and ease
of assembly and
disassembly, the invention is not limited to this two-piece contactor body.
It will be noted particularly from the section views of Figures 3 and 6 that
the first
and second end portions, 44 and 45 respectively, of the foodstuff flow passage
generally
define flow areas. The minimum transverse dimension of each end portion flow
area
reduces down from a relatively large transverse dimension at the outer ends of
the flow
passage to a relatively smaller minimum transverse dimension in a flow area
defined by
contact passage 46. As shown best in the end view of Figure 6, the preferred
contact
passage 46 forms an elongated oval in transverse cross section. Contact
passage 46 is thus
defined between two narrowly spaced opposing surfaces or contact passage walls
indicated
by reference numerals 56 and 57. These two surfaces 56 and 57 are both
generally planar
and extend parallel to each other. When a comminuted foodstuff is forced to
flow through
the contactor 40, the foodstuff is forced into contact passage 46 where it
forms a thin planar
sheet of material. The sheet of material has a relatively small minimum
transverse
dimension, preferably on the order of a dimension of the pieces of material
making up the
comminuted foodstuff being treated or less. When the transverse dimension is
less that the
size of the pieces of material making up the comminuted foodstuff, the
foodstuff pieces
spxead out laterally in order to travel through the contact passage.
Process fluid chamber 49 in the forms of the invention shown in Figures 2
through
6 comprises an ammlar area machined or otherwise formed in components 41 and
42
around the area that receives insert 48 or 48'. This annular area is shown
divided by ribs 60
into separate longitudinally spaced apart chambers 61 in communication with
each other
through rib openings 62. Ribs 60 help support the respective insert 48 or 48'
in the desired
position. Processing fluid may enter chamber 61 through a processing fluid
passage 64
formed in contactor body inlet component 41. Processing fluid passage 64 may
also be
associated with a suitable connection 65 for connecting to a processing fluid
supply conduit
(not shown) for supplying processing fluid to contactor 40.
The fluid communication arrangement in the form of the invention shown in
Figure
3 includes a number of the small openings 67 drilled or otherwise formed
through the
material of insert 48 separating contact passage 46 and processing fluid
chamber 49. These
openings 67 preferably have a small transverse dimension no greater than about
0.10 inches
for processing cornminuted meats, and are illustrated in the enlarged section
view of Figure
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4. Although openings 67 may be any size that allows the desired processing
fluid contact
with the foodstuff, the small openings are preferred because they allow
processing fluid to
flow from processing fluid chamber 49 into contact passage 46 to effect the
desired contact
with the foodstuff, but help prevent the foodstuff from flowing from the
contact passage
into the processing fluid chamber. It will also be appreciated that the
processing fluid
pressure maintained in chamber 49 also prevents foodstuffs from inadvertently
flowing
through openings 67 from contact passage 46 into processing fluid chamber 49.
In the
preferred form of the invention, a large number of the openings 67 are spaced
apart across
the entire width of each contact passage wall 56 and 57 in each chamber 61.
Openings 67
are also preferably included in both lateral ends of contact passage 46.
The alternate form of the invention shown in Figure 6 employs a porous and
permeable material for the insert 48' in place of the solid and machined
insert 48 shown in
Figures 3 and 4. This material is permeable to the processing fluid and thus
allows the
processing fluid to flow from processing fluid chamber 49 into contact passage
46 under a
suitable driving pressure differential between the processing fluid chamber
and contact
passage. However, the opeiungs that produce the desired permeability are
preferably small
enough to inhibit foodstuff from flowing from contact passage 46 into
processing fluid
chamber 49. Ceramics and sintered materials or any other suitable material
having the
desired permeability to the processing fluid may be used to form insert 48'.
Composite
inserts made up of solid material and permeable material sections may also be
employed
within the scope of the invention.
In both the discrete opening form of the fluid communication arrangement shown
in
Figures 3 and 4, and the permeable material fluid communication arrangement
shown in
Figure 8, the openings provide fluid communication from chamber 49 to contact
passage
46. That is, the openings at least allow processing fluid to pass from chamber
49 to contact
passage 46 given the appropriate pressure in chamber 49. The openings that
provide the
fluid communication may be sized and shaped to inhibit flow of foodstuff from
contact
passage 46 to chamber 49, but it is not required. Rather, the pressure in
chamber 49 may
be controlled to prevent foodstuff from flowing into the openings making up
the fluid
communication arrangement.
Whether the sheet of material is planar as in contactor 40 or
annular/cylindrical as
in contactor 15, or some other shape, the thin sheet of foodstuff rnay be
exposed to the
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processing fluid in an even and consistent manner. That is, the relatively
thin sheet of
foodstuff material may be exposed on both sides or major surfaces to the
processing fluid.
Where the spacing between the opposing surfaces of the contact passage is
approximately
equal to a dimension of foodstuff pieces malting up the comminuted foodstuff,
applying the
processing fluid to the thin sheet generally ensures that each piece of the
foodstuff is
directly exposed to the processing fluid. This is to be contrasted with the
situation in
which a processing fluid is simply injected into a foodstuff flowing through a
large conduit.
W that case the processing fluid is inherently applied unevenly with some
pieces directly
exposed and other pieces exposed only indirectly.
Figures 7 through 10 illustrate forms of the present invention which include a
number of contact passages configured as passages through a sparging screen.
Referring to
Figure 8, a sparging screen 80 embodying the principles of the invention
includes a screen
body made up of a first or inlet side component 81 and a second or outlet side
component
82. A number of screen passages, each shown generally by reference numeral 84,
extend
through the sparging screen body from a first side 87 of the screen body to a
second side 88
of the screen body. As shown best in Figure 7, a number of screen passages 84
are spaced
apart across the entire area of the disk-shaped screen body. The illustrated
arrangement of
screen passages 84 includes an outer set of passages shown generally at
reference numeral
90 and an inner set of passages shown at reference numeral 91. Each set 90 and
91 is made
up of a number of pairs 92 of generally radially aligned screen passages 84,
with each pair
at a different angular orientation about a center point 93 of the screen body.
As shown best in Figure 8, sparging screen 80 also includes a fluid chamber 95
formed within the screen body. In this form of the invention, fluid chamber 95
is defined
between the opposing surfaces of first side component 81 and second side
component 82.
Fluid chamber 95 may be formed between the two components 81 and 82 by areas
machined or otherwise formed in one or both of the opposing surfaces. Fluid
chamber 95
is in fluid connnunication with an imler ring 97 associated with inner screen
passage set 91
and an outer ring 98 associated with outer screen passage set 90. Both the
inner ring 97
and outer ring 98 are connected to a feed passage 100 formed in first side
component 81
and terminating at an inlet port 101 formed in the first side component. Inlet
port 101
comprises a fitting for connecting with a suitable processing fluid supply
conduit (not
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shown). The combination of feed passage 100, and inner and outer rings, 97 and
98
respectively, provide fluid communication from inlet port 101 to fluid chamber
95.
The sparging screen 80 shown in Figures 7 and 8 includes a fluid communication
device associated with each screen passage 84. This fluid connnuucation device
males up
5 the fluid communication arrangement in this form of the invention and, as
best shown in
the section view of Figure 8, comprises a cylindrical sleeve 104 captured
between first side
component 81 and second side component 82. The sides of the respective sleeve
104
separate the area of fluid chamber 95 from the area of the respective screen
passage. Thus,
each sleeve 104 actually defines a central portion of the respective screen
passage 84, with
10 the remainder of the respective screen passage being defined by an opening
107 formed in
first side component 81 and an opening 108 formed in second side component 82.
In some
forms of the invention the material making up sleeve 104 may include small
openings
extending transversely from the outer surface of the cylindrical shape to the
inner surface.
Other forms of the invention may utilize sleeves 104 made up of a porous and
pernleable
material. In either case, the openings in each sleeve 104 provide fluid
communication from
fluid chamber 95 to the respective screen passage 84.
The two side components 81 and 82 of screen 80 shown in Figure 8 may be held
together in any suitable fashion in a sparging device embodying the principles
of the
present invention. For example, the two side components 81 and 82 may be
sandwiched
between flanges (not shown) in a sparging device or may otherwise be bolted
together.
The illustrated disk-shaped screen 80 made up of side components 81 and 82 is
especially
adapted to be used as a grinder plate in a grinder device. Thus, screen 80
includes a central
opening 110 for accormnodating a spindle associated with the grinding device.
Referring to Figures 9 and 10 a multiple-stage sparging device 120 embodying
the
principles of the invention includes a sparger body or screen body 121 having
multiple
fluid chambers for adding different processing fluids to a foodstuff passing
through sparger
or screen passages 124 in the sparger body. Referring particularly to Figure
10, this form
of the invention includes two different fluid chambers, a first fluid chamber
indicated
generally at reference numeral 127 and a second fluid chamber indicated
generally at
reference numeral 128. Sparger device body 121 is connected to an inlet
chamber 130
through which foodstuff may be introduced to the various sparger passages 124
and forced
through the passages.
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In the form of the invention shown in Figures 9 and 10, sparger body 121
includes
an inlet side component 132, an intermediate component 133, and an outlet side
component
134. Intermediate component 133 is sandwiched between inlet side component 132
and
outlet side component 134. First fluid chamber 127 is defined between the
facing surfaces
of inlet side component 132 and intermediate component 133, while second fluid
chamber
128 is defined between the facing surfaces of intermediate component 133 and
outlet side
component 134. Sparger screen body 121 in this form of the invention also
includes a
scraper plate 135 interposed between inlet side component 132 and inlet
chamber 130.
This scraper plate 135 provides a surface against which a scraper blade or
grinder blade
may work as will be described further below.
It will be appreciated especially from the section view of Figure 10 that
inlet side
component 132, intermediate component 133, outlet side component 134, amd
scraper plate
135 each include transverse openings that align to either make up part of the
respective
sparger passage 124 or make room for the respective sparger passage. W
particular, scraper
plate 135 includes transverse openings 137, inlet side component 132 includes
openings
138, intermediate component 133 includes openings 139, and outlet side
component 134
includes openings 140. The bulk of each sparger passage 124 in the form of the
invention
shown in Figures 9 and 10 is defined by a sleeve or insert 142 captured in the
sparger body
121 between scraper plate 135 and outlet component 134. Each sleeve 142 fits
in a recess
defined by openings 138, 139, and 140.
The particular sleeve 142 shovcm in Figure 10 comprises a single component
having
a generally uniform cylindrical inner surface 143 formed through solid
material sections
144, 145, and 146, and two porous and permeable material sections 147 and 148.
Porous
and permeable material section 147 aligns with first fluid chamber 127 while
porous and
permeable material section 148 aligns with second fluid chamber 128. Thus, the
porous
and permeable material 147 provides a fluid communication device for
communicating
fluid from fluid chamber 127 to sparger passage 124 and porous and permeable
material
148 provides a fluid communication device for communicating fluid from second
fluid
chamber 128 to the sparger passage. As with the sleeve 104 shown in the
embodiment of
Figures 7 and 8, the fluid communication device in this multiple-stage form of
the
invention may alternatively include small openings drilled or otherwise formed
through the
sleeve material from the outside surface of the cylindrical shape to the
inside surface.
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Each fluid chamber 127 and 128 formed in sparger body 121 may be used to add a
different processing fluid to the foodstuff as the foodstuff is forced through
sparger
passages 124. Thus, each fluid chamber 127 and 128 is associated with a
different
processing fluid inlet or feed structure for feeding a desired processing
fluid into the
respective fluid chamber. The feed structures shown in Figure 10 include a
first inlet
passage 151 associated with first fluid chamber 127 and a second inlet passage
152
associated with second fluid chamber 128. First inlet passage 151 extends
through inlet
side component 132 from a fitting 153 formed in an exterior surface of the
inlet side
component to an interior surface defining a portion of first fluid chamber
127. Similarly,
second inlet passage 152 extends through outlet side component 134 from an
exterior
fitting 154 to an interior surface defining a portion of second fluid chamber
128.
As shown in Figure 10, inlet chamber 130 is in communication with a foodstuff
inlet port 156 through which foodstuff may be introduced into the inlet
chamber. A
pressure auger 158 may be associated with inlet chamber 130. Auger 158 is
driven about
an auger axis 159 by a suitable driving arrangement (not shown) to force the
foodstuff from
inlet chamber 130 into sparger passages 124. Also, inlet chamber 130 may house
a scraper
blade assembly 160 mounted at the end of auger 158 and adapted to rotate with
the auger.
As best shown in Figure 9, the illustrated scraper blade 160 comprises a
single elongated
element. Other forms of the invention may include scrapers having several
radial
extending blade elements. In any case, the scraper periodically passes over
scraper plate
openings 137 to sever material against the entrance edge of these openings.
This cutting
action is analogous to the cutting action at the plate of a meat grinding
device. It will be
noted that the orientation of scraper 160 shown in Figures 9 and 10 is such
that the section
view of Figure 10 coincides with the longitudinal axis of the scraper. Thus,
the section
view of Figure 10 shows the scraper 160 completely filling the area defined by
inlet
chamber 130. It will be appreciated from Figure 9 however that scraper 160
occupies only
a small portion of the inlet chamber so that the foodstuff to be treated may
enter chamber
130 through inlet port 156 and then flow from chamber 130 into each of the
sparger
passages 124 extending through sparger body 121.
Although the forms of the invention shown in Figures 7 through 10 are
preferred
forms of the invention, those skilled in the art will appreciate that many
variations in these
devices are possible within the scope of the present invention as defined in
the
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accompanying claims. For example, a sparging device embodying the principles
of the
invention may or may not include cutting elements for scraping an inlet
surface to the
sparger passages, such as the upper surface of plate 135 in Figure 10. In
particular, a finely
ground or otherwise comminuted foodstuff may not require any cutting action at
the inlet to
the sparger passages. Also, numerous different arrangements other than an
auger may be
used to force the foodstuff through the sparger passages. In particular, in
the arrangement
shown in Figures 9 and 10, the foodstuff may be pumped into inlet chamber 130
through
foodstuff inlet port 156 with sufficient force to drive the foodstuff through
sparger passages
124.
Those skilled in the art will appreciate that many different arrangements may
be
used to connect the various components of the screen body. The components may
be
sandwiched between flanges formed on other components, or the components may
themselves include bolt holes to accommodate bolts or other connectors for
correcting the
components together in the positions illustrated particularly in Figures 8 and
10. Many
different sealing arrangements may also be used to seal between the various
facing surfaces
of a screen body embodying the principles of the invention. For example,
Figure 10 shows
O-rings 162 providing a seal between the facing surfaces of inlet side
component 132,
intermediate component 133, outlet side component 134, and scraper plate 135.
Figure 10
also shows O-rings 163 associated with the solid material sections of sleeves
142. These
sealing arrangements are shown only for purposes of example and are not
intended to limit
the scope of the invention as defined in the following claims.
The sparger or screen passages ~4 and 124 shown in the two illustrated
embodiments of the invention are preferably relatively small in diameter. For
example,
each passage may have a diameter of around one-half inch or less, although
larger
diameters are possible within the scope of the invention. The use of
relatively small
diameter sparger passages facilitates better contact between the processing
fluid and the
foodstuff passing through the sparger passages. Also, length of the areas
provided for
processing fluid communication to the sparger passages may vary widely within
the scope
of the invention. Figure ~, for example shows a relatively short sleeve 104,
while the
porous and permeable sections 147 and 14~ shown in Figure 10 are relatively
long.
Generally, the longer the area provided for fluid communication between the
respective
CA 02490237 2004-12-15
WO 03/105598 PCT/US03/19221
14
chamber and the sparger passage, the more processing fluid that can be sparged
into the
foodstuff.
The form of the invention shown in Figure 10 includes openings 140 in outlet
side
component 134 that taper narrower toward their respective outlet end. This
taper is
included to provide increased resistance to the flow of foodstuff through
passages 124.
The increased resistance results in higher pressures within flow passages 124.
This
increased pressure allows the processing fluid to be sparged into the
foodstuff through
chambers 127 and 128 at a higher pressure. The higher sparging pressure may be
advantageous for certain foodstuffs and certain processing fluids. In other
forms of the
invention, the length and diameter of passages 124 may be such that the
passages
themselves provide sufficient resistance to flow to produce the desired back
pressure.
The above described preferred embodiments are intended to illustrate the
principles
of the invention, but not to limit the scope of the invention. Various other
embodiments
and modifications to these preferred embodiments may be made by those slcilled
in the art
~ without departing from the scope of the following claims. For example, the
invention is
not limited by specific materials for the various contactor components.
Generally, the
contactor body components may be formed from stainless steel, however, any
material
suitable for food handling may be used provided the material has suitable
strength and
other material characteristics. Porous and permeable material used in the
fluid
communication arrangement may comprise any suitable material. Also, the
invention is
not limited to a contact passage minimum transverse dimension equal to a
dimension of the
foodstuff pieces being treated. A single layer or line of foodstuff pieces
passing through
the contact passage is preferred for the reasons described above, but is not
required.
