U.S. patent application number 14/501223 was filed with the patent office on 2015-01-15 for system and method for treating live cargo such as poultry with gas.
The applicant listed for this patent is Gary Dee Lang, Narsimha R. Nayini. Invention is credited to Gary Dee Lang, Narsimha R. Nayini.
Application Number | 20150017894 14/501223 |
Document ID | / |
Family ID | 38854037 |
Filed Date | 2015-01-15 |
United States Patent
Application |
20150017894 |
Kind Code |
A1 |
Lang; Gary Dee ; et
al. |
January 15, 2015 |
SYSTEM AND METHOD FOR TREATING LIVE CARGO SUCH AS POULTRY WITH
GAS
Abstract
Animals such as poultry are stunned while still caged and on a
vehicle or stationary platform prior to processing the animal by
isolating the atmosphere surrounding the animal, adjusting the
composition of the isolated atmosphere by introducing a gaseous
mixture that brings the animal to the desired state, and evacuating
or exhausting the gaseous mixture.
Inventors: |
Lang; Gary Dee; (Naperville,
IL) ; Nayini; Narsimha R.; (Burr Ridge, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lang; Gary Dee
Nayini; Narsimha R. |
Naperville
Burr Ridge |
IL
IL |
US
US |
|
|
Family ID: |
38854037 |
Appl. No.: |
14/501223 |
Filed: |
September 30, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14091671 |
Nov 27, 2013 |
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14501223 |
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|
11508703 |
Aug 23, 2006 |
8597089 |
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14091671 |
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11230547 |
Sep 21, 2005 |
7794310 |
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11508703 |
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11176277 |
Jul 8, 2005 |
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11230547 |
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Current U.S.
Class: |
452/66 |
Current CPC
Class: |
A22B 3/086 20130101;
A22B 3/00 20130101; A22B 3/005 20130101; A22B 3/08 20130101; A22B
1/00 20130101 |
Class at
Publication: |
452/66 |
International
Class: |
A22B 3/00 20060101
A22B003/00; A22B 3/08 20060101 A22B003/08 |
Claims
1. A method for treating live cargo with a gaseous mixture
comprising the steps of: (i) placing the live cargo on a platform;
(ii) shrouding the cargo on the platform to isolate the atmosphere
proximate the cargo; and (iii) introducing the gaseous mixture to
the shrouded cargo to alter the composition of the isolated
atmosphere and impart a desired effect on the live cargo.
2. The method according to claim 1 further comprising the steps of
monitoring the isolated atmosphere and adjusting the gaseous
mixture in response thereto.
3. The method according to claim 1 wherein the step of shrouding
the cargo further comprises disposing a moveable enclosure around
the cargo on the platform to sealably isolate the atmosphere
proximate the cargo.
4. The method according to claim 1 wherein the platform is a
trailer adapted to be transported by a vehicle.
5. The method according to claim 1 wherein the platform is
stationary.
6. The method according to claim 1 wherein the step of shrouding
the cargo further comprises shrouding only a portion of the cargo
on the platform to isolate the atmosphere proximate the portion of
the cargo area.
7. The method according to claim 1 wherein the step of placing the
live cargo on the platform further comprises off-loading the live
cargo from a vehicle adapted to transport the live cargo to the
platform in a cargo treatment area.
8. The method according to claim 1 wherein the step of shrouding
the cargo further comprises laterally moving a moveable enclosure
adjacent to the cargo on the platform to isolate the atmosphere
proximate the cargo.
9. The method according to claim 1 wherein the step of shrouding
the cargo further comprises lowering an enclosure around the cargo
on the platform to sealably isolate the atmosphere proximate the
cargo.
10. The method according to claim 1 wherein the step of introducing
a gaseous mixture to the shrouded cargo further comprises injecting
gas into the isolated atmosphere.
11. The method of claim 1 wherein the live cargo is poultry
disposed in cages.
12. The method of claim 1 wherein the gaseous mixture is an
oxygen-depleted gaseous mixture.
13. The method of claim 1 wherein the step of introducing the
gaseous mixture to alter the composition of the isolated atmosphere
further comprises: introducing the gaseous mixture to the isolated
atmosphere at a first concentration sufficient to bring the live
cargo to a state of lethargy; further introducing the gaseous
mixture to the isolated atmosphere at a second concentration
sufficient to bring the live cargo to a state of unconsciousness;
and still further introducing the gaseous mixture to the isolated
atmosphere at a third concentration sufficient to asphyxiating the
cargo or bring the cargo to an unrecoverable state.
14. The method of claim 7 wherein the gas injected into the
isolated atmosphere comprises carbon dioxide.
15. A method for batch treatment of live cargo on a vehicle having
a cargo area adapted to transport live cargo, the method comprising
the steps of: (i) shrouding a portion of the cargo area to isolate
the atmosphere proximate the portion of the cargo area; (ii)
introducing a gaseous mixture to the shrouded portion of the cargo
area to alter the composition of the isolated atmosphere and impart
a desired effect on the live cargo.
16. The method according to claim 15 further comprising the steps
of monitoring the isolated atmosphere and adjusting the
introduction of the gaseous mixture in response thereto.
17. The method according to claim 15 wherein the step of shrouding
a portion of the cargo area further comprises sealably disposing a
moveable enclosure adjacent to the portion of the cargo area
thereby isolating the atmosphere proximate the portion of the cargo
area.
18. The method according to claim 15 wherein the step of shrouding
a portion of the cargo area further comprises moving the vehicle
through an enclosure structure.
19. The method according to claim 15 wherein the step of shrouding
a portion of the cargo area further comprises moving the vehicle
into a pit area and placing a cover or barrier around the portion
of the cargo area while the vehicle remains in the pit area.
20. The method according to claim 15 wherein the step of
introducing a gaseous mixture to the shrouded portion of the cargo
area further comprises injecting gas into the isolated
atmosphere.
21. The method of claim 15 wherein the live cargo is poultry.
22. The method according to claim 15 further comprising the steps
of: (iii) exhausting the gaseous mixture within the isolated
atmosphere proximate the shrouded portion of the cargo area; (iv)
shrouding a second portion of the cargo area to isolate the
atmosphere proximate the second portion of the cargo area; (v)
introducing a gaseous mixture to the shrouded second portion of the
cargo area to alter the composition of the isolated atmosphere.
23. The method of claim 15 wherein the gaseous mixture is an
oxygen-depleted gaseous mixture.
24. The method of claim 15 wherein the step of introducing the
gaseous mixture to alter the composition of the isolated atmosphere
further comprises: introducing the gaseous mixture to the isolated
atmosphere at a first concentration sufficient to bring the live
cargo to a state of lethargy; further introducing the gaseous
mixture to the isolated atmosphere at a second concentration
sufficient to bring the live cargo to a state of unconsciousness;
and still further introducing the gaseous mixture to the isolated
atmosphere at a third concentration sufficient to asphyxiating the
cargo or bring the cargo to an unrecoverable state.
25. The method of claim 20 wherein the gas injected into the
isolated atmosphere comprises nitrogen.
26. The method of claim 20 wherein the gas injected into the
isolated atmosphere comprises carbon dioxide.
27. A method for batch treatment of live cargo confined to one or
more cages with a gas comprising the steps of: (i) isolating the
atmosphere proximate the confined live cargo in a manner that
allows a flow through the one or more cages; (ii) introducing the
gas to the isolated atmosphere; (iii) forcibly circulating the gas
entrained in the isolated atmosphere through the cages to treat the
live cargo; and (iv) evacuating the gas within the isolated
atmosphere when the treatment is completed.
Description
[0001] This application is a continuation of Ser. No. 14/091,671,
filed Nov. 27, 2013, which is a continuation of Ser. No. 11/508,703
filed Aug. 23, 2006, now U.S. Pat. No. 8,597,089, which is a
continuation-in-part of application Ser. No. 11/230,547 filed Sep.
21, 2005, now U.S. Pat. No. 7,794,310, which is a
continuation-in-part of application Ser. No. 11/176,277 filed Jul.
8, 2005, now abandoned.
FIELD OF THE INVENTION
[0002] The present invention relates to methods and apparatus
useful for treating live cargo such as poultry, by placing them in
an atmosphere that when breathed renders them progressively
lethargic and then unconscious or dead.
BACKGROUND OF THE INVENTION
[0003] Commercial production of poultry (by which is meant chicken
and turkey) products destined for sale for consumption customarily
is carried out in processing plants. Presently, in about 95% of
current processing plants, poultry is brought in by truck in cages
from which the poultry is unloaded live by hand or unloaded from
the truck by machine and subsequently dumped for further
processing. The birds are then hung upside-down on a conveyorized
shackle line and their heads are dragged through a brine or water
bath. They are then stunned using high voltage electricity just
prior to being slaughtered.
[0004] Hanging the birds while they are still fully awake can be
very troublesome, especially with heavier birds such as tom turkeys
which can weigh 40 pounds or more, leading to high labor costs and
worker injuries. It is not unusual for the birds to flap their
wings, causing joint damage and blood clots in the birds, thus
degrading the overall quality of the meat and reducing the
yield.
[0005] Stunning the poultry with gas as part of the processing
regimen presents the advantage that the birds are less likely to
engage in extensive movement, thereby reducing the burden to the
worker and reducing the risk of damage to the bird. Poultry
processors have studied the relative costs of their current methods
versus gas stunning and have documented that gas stunning can
prevent on the order of $700,000 per shift per year in lost product
revenues for a typical turkey processor. Since the majority of
processors employ two shifts per day, gas stunning can save on the
order of $1.4 million per year.
[0006] However, current gas stunning systems are complicated and
expensive, with upfront installation costs of 2 to 3 million
dollars per line. The installation costs include costs of special
cages, mechanized cage handling systems, and additional plant space
which usually must be added to the current buildings of the
processor.
[0007] Thus, there is a need for effective gas stunning techniques,
without incurring the complexity and expense of current gas
stunning methods and apparatus.
BRIEF SUMMARY OF THE INVENTION
[0008] In a broad aspect, the invention may be characterized as
method for treating live cargo with a gaseous mixture. One of such
methods comprises the steps of: placing the live cargo on a
platform; shrouding the live cargo on the platform to isolate the
atmosphere proximate the live cargo; and introducing a gaseous
mixture to the shrouded cargo to alter the composition of the
isolated atmosphere and impart a desired effect on the live
cargo.
[0009] In another aspect, the invention may be characterized as
method for treating live cargo on a vehicle having a cargo area
adapted to transport live cargo. This method for treating live
cargo on a vehicle comprises the steps of shrouding a portion of
the cargo area to isolate the atmosphere proximate the portion of
the cargo area and introducing a gaseous mixture to the shrouded
portion of the cargo area to alter the composition of the isolated
atmosphere and impart a desired effect on the live cargo.
[0010] Finally, the invention may also be characterized as method
for treating live cargo confined to one or more cages with a gas.
In this regard, the method comprises the steps of: isolating the
atmosphere proximate the confined live cargo in a manner that
allows a flow through the one or more cages; introducing the gas to
the isolated atmosphere; forcibly circulating the gas entrained in
the isolated atmosphere through the cages to treat the live cargo;
and evacuating the gas within the isolated atmosphere when the
treatment is completed.
[0011] Some of the advantages associated with the present methods
of treating live cargo such as poultry, over the prior art poultry
stunning systems is that the presently disclosed embodiments
establish the isolated atmosphere around the live cargo rather than
conveying or moving the poultry through a stunning chamber. By
bringing an isolated atmosphere to the live cargo, the parameters
associated with the stunning operation, namely the relative
concentrations of the gases in the isolated atmosphere and the
exposure time of the live cargo in the isolated atmosphere can be
precisely controlled. This in turn translates to an effective and
efficient stunning or treating operation and one that is easily
adjustable in response to facility constraints or other operational
variations.
[0012] Other advantages associated with the present method relate
to the precise control of isolated atmosphere and its circulation
during the stunning process as well as precise control of the
atmosphere evacuation or exhaust process. Unlike the prior art
`passive` systems, the present method forces the flow of the
isolated atmosphere through the cages, which contain the live cargo
and forces the evacuation of the isolated atmosphere at the
appropriate time, such that the desired effect on the live cargo is
attained in a very short time and in the safest possible manner.
This forcible flow of the gases within isolated atmosphere in
conjunction with the regulated control of the concentrations of the
gases in the isolated atmosphere and the exposure times at the
various concentrations provide overall efficiency to the stunning
operations as well as flexibility to customize or tailor the
preferred methods at different processing facilities.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other aspects, features, and advantages of the
present invention will be more apparent from the following, more
descriptive description thereof, presented in conjunction with the
following drawings, wherein:
[0014] FIG. 1 is a perspective view from the outside of apparatus
useful in practicing the invention;
[0015] FIG. 2 is a cross-sectional view of apparatus according to
the embodiment shown in FIG. 1;
[0016] FIG. 3 is a top view of apparatus according to one
embodiment of the invention;
[0017] FIG. 4 is a perspective view of an alternate embodiment of
the apparatus useful in practicing the invention; and
[0018] FIG. 5 is another perspective view of the alternate
embodiment similar to the apparatus of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Animals that can be treated by this invention include any
that live by breathing the ambient atmosphere. Preferred examples
include poultry (i.e. chickens and turkeys), ducks and other birds,
as well as mammals such as cattle, calves, sheep, goats and
pigs.
[0020] The animals that are to be treated by the method of the
present invention are transported to a treatment location from
another location, preferably from a location at which the animals
have been placed into cages or otherwise confined. Then, the cages
are transported to the treatment location, such as on a truck or
other vehicle. The cages or other structure that confines the
animals are of any design that contains the animal and prevents it
from escaping, and that permits gaseous atmosphere to pass from
outside the cage into and through the cage or ranks of cages.
Preferably, the tops, bottoms and sides of the cages are planar, to
facilitate stacking them onto a vehicle. It is immaterial whether
the animals are confined one per cage, or more than one per
cage.
[0021] As used herein, a "rank" of cages means a cage or cages
lying in a vertical plane that extends from one lateral side of the
enclosure described herein to the other lateral side. Thus, the
term "rank" of cages includes without limitation one cage, or two
or more cages stacked vertically, or two or more vertical stacks of
cages placed side by side (whether touching each other or not).
[0022] The confined animals arrive at the treatment location alive.
They are in, and breathing, an ambient atmosphere that does not
(yet) bring them to a state of lethargy, unconsciousness or death.
Typically, the animals are breathing the ambient air.
[0023] Next, steps are taken so that the composition of the
atmosphere that the animals are breathing changes to a composition
that, when breathed, brings the animals to whichever state is
desired by the operator, that is, to a state of lethargy,
unconsciousness, or death. It will of course be recognized that
animals may pass through one of these states to the next. The terms
"stunning" and "stun" are used herein to mean bringing an animal
into a desired state of lethargy, unconsciousness or death through
asphyxiation.
[0024] The composition of the atmosphere being breathed by the
animals is changed so that the oxygen content of that atmosphere is
decreased. Changing the composition can be carried out in many
different ways. A feature common to all these ways is that the
composition changes, and the animals are subjected to breathing the
composition, while the animals remain confined on the vehicle.
[0025] One manner of changing the composition of the atmosphere and
of subjecting the animals to the changing composition is to employ
a structure through which the vehicle can pass. The vehicle can
move through the structure while the structure (i.e. a shed or a
garage) remains stationary, or the structure can be mobile (e.g.
mounted on wheels) and pass along the length of the vehicle which
remains stationary, or the vehicle and the structure can both move
relative to the ground and relative to each other. The structure
can be shorter than the vehicle, so that only a portion at a time
of the vehicle is inside the structure (an example of this is
illustrated in FIG. 3). Instead, the structure can be as long as or
longer than the vehicle, so that the entire vehicle can fit inside
the structure at one time. The composition of the atmosphere within
the structure is then changed (as described below) so that animals
that are in the cages within the structure are exposed to the
changed atmosphere, breathe it, and are thereby brought to the
desired state. After the treatment, the vehicle is moved relative
to the structure so that the animals that have been breathing the
changed atmosphere and have been brought to the desired state exit
the structure. An example of this type of structure is illustrated
in FIGS. 1-3 and is described in more detail below.
[0026] Another manner of changing the composition of the atmosphere
to which the animals are subjected employs a flexible, removable
wrapper such as a large sheet of plastic, tarpaulin, blanket, or
the like, which is placed around all of the cages, or around
selected ranks of cages, following which the composition of the
atmosphere in the space within the wrapper is changed to expose the
animals confined within that space to the changed atmosphere. After
the treatment, when the animals have been brought to the desired
state, the wrapper is removed.
[0027] Yet another manner of changing the composition of the
atmosphere to which the confined animals are exposed employs a pit
or equivalent depression below the grade of the ground which is at
least as deep as the height of the vehicle plus the cages it is
carrying, into which the vehicle is driven or rolled down a
suitable ramp. The composition of the ambient atmosphere is then
changed, preferably after barriers are closed above and around the
vehicle and the cages to prevent excessive loss of the atmosphere
while the animals on the vehicle are being exposed to the changed
atmosphere. After the treatment, the animals are removed from the
pit, either by removing the cages from the pit or by driving or
rolling the vehicle out of the pit with the cages still on the
vehicle.
[0028] In any of these embodiments, the gas treatment of the
animals can be carried out while the vehicle is stationary, or
while the vehicle remains in motion.
[0029] To bring about the desired change in the composition of the
atmosphere to which the animals are exposed, a gaseous component or
a mixture of gaseous components is fed into the atmosphere to which
the animals are exposed. The component or mixture changes the
composition of the atmosphere being breathed by the animals to a
composition with decreased oxygen content, so that breathing it
brings the animals breathing it to the desired state of lethargy,
unconsciousness or death.
[0030] The gaseous component or mixture of components fed into the
circulating atmosphere should not themselves be toxic to the animal
but inert, bringing about the desired state by gradually
asphyxiating the animal i.e. by reducing the oxygen content of the
atmosphere that the animal breathes. Suitable gases include carbon
dioxide, nitrogen, argon, and mixtures thereof. It should be noted
that the gas or mixture of gases being added can be oxygen-free or
can contain oxygen, so long as the overall oxygen content of the
atmosphere being breathed decreases.
[0031] The atmosphere that renders the animal lethargic generally
comprises 5% to 25% of one or more of such gases. When the gas
being added comprises nitrogen, the concentration thereof should be
increased above the level already present in the ambient
atmosphere. The one or more gases should be added in sufficient
amount, over sufficient time, to bring the oxygen concentration in
the atmosphere being breathed by the animal to below 10% by weight,
preferably below 5% by weight, and more preferably to below 2% by
weight, or even below 1% by weight. Adding carbon dioxide until the
concentration thereof reaches about 20 weight %, for example,
establishes an atmosphere that when breathed by poultry renders the
poultry lethargic. The atmosphere that is thereby established is
typically maintained for 30 to 60 seconds, during which the animal
becomes at least lethargic.
[0032] Continuing to add such a component or components to increase
its concentration in the circulating atmosphere, and thereby
reducing the oxygen concentration of the atmosphere, converts the
atmosphere to a composition that when breathed by the animal for a
sufficient time renders the animal unconscious or dead. For reasons
of economy and efficiency, the same component or components
injected to render the animal lethargic should be added to render
the animal unconscious or dead. Generally, the concentration of the
component or components should be increased to about 45% to 55% by
weight, e.g. of carbon dioxide or other inert gas or combination of
inert gases, and even higher when the gas being added comprises
nitrogen. When the circulating atmosphere has reached this
composition, circulation should be maintained for another 1 to 6
minutes, until the animals are unconscious or dead (the length of
time depends on the desired final state of the animal following
this treatment, the animal, and its size).
[0033] The addition of the component that is to have the desired
effect on the animal can be governed automatically by an automated
controller into which has been inputted the desired concentration
of the component(s), and optionally also the desired rate of
increase of the concentration of the component(s), that responds to
measurements of the concentration that are provided by a suitable
probe by adding the component(s) to bring about the desired
concentration. It can be advantageous to govern the addition of the
component(s) in response also to a desired rate of increase of the
concentration, as animals may exhibit convulsive behavior or other
excessive movement if the concentration of the stunning
component(s) increases too quickly.
[0034] The addition of gas can occur without interruption
throughout a treatment cycle, or can occur intermittently. When the
composition of the atmosphere has reached the desired level,
addition can be discontinued but one may wish to continue addition
at a reduced flow rate to account for losses of the component(s)
being added to the surrounding atmosphere.
[0035] The length of time that is necessary for a given atmosphere
to render the animal lethargic, and the length of time necessary to
reach unconsciousness or death, will depend on the component or
components being used, on the component concentration, and on the
type of animal and its size, and can be determined experimentally.
In the preferred embodiments, poultry are exposed to multiple
levels or stages of carbon dioxide concentration including: (1) a
first stage where carbon dioxide level is increased to about 30
percent volume in air for a duration of about 45 seconds to
anesthetize the poultry; (2) a second stage where carbon dioxide
level is increased to about 45 percent volume in air for a duration
of about 45 seconds to immobilize the poultry; and (3) a third
stage where carbon dioxide level is increased to between about 55
and 65 percent volume in air for a duration of about 120 seconds
such that the poultry reach an unrecoverable state.
[0036] When the animal being exposed to the circulating atmosphere
has reached the desired state of lethargy, unconsciousness or
lifelessness, addition of gas can be discontinued. Preferably, the
isolated atmosphere is exhausted and replaced with ambient air.
[0037] When treatment of the animals is completed, the animal can
be removed from its cage, either while the cage is still on the
vehicle, or after the cage has been removed from the vehicle to
facilitate taking the stunned or asphyxiated animal out of its
cage. The animal can be subjected to further processing which
typically can include slaughtering and dressing the carcass in any
desirable fashion.
[0038] The following is a description of one embodiment of the
invention, which is illustrated in FIGS. 1-3. The embodiment is
described with respect to treatment of poultry, although this
embodiment can be practiced with any other animals instead.
[0039] Referring first to FIG. 1, apparatus useful in the practice
of this invention includes enclosure 1 which has top 2 and sides 3
and 4. Top 2 and sides 3 and 4 are gas impermeable and may be
formed of sheet metal or other gas impermeable material. Sides 3
and 4 should be attached to top 2 in any manner that does not
permit gas to flow through the joints between top 2 and each of
sides 3 and 4.
[0040] Enclosure 1 also includes front panel 5 in which is formed
entrance 6, and rear panel 7 in which is formed exit 8. As
illustrated, entrance 6 and exit 8 lie along a line such that a
vehicle can pass into entrance 6, through the interior of enclosure
1, and out exit 8, all along the same straight line. Thus, a
passageway is formed by the vertical and horizontal edges in panels
5 and 7 that define entrance 6 and exit 8. The enclosure should
also be wide enough to enclose lateral spaces 21 and 22 that are
defined by sides 3 and 4 (respectively) and top 2 and front and
rear panels 5 and 7. In overall dimensions, the passageway through
enclosure 1 is high enough and wide enough that a vehicle such as a
flatbed truck carrying stacked poultry cages can pass through
it.
[0041] Enclosure 1 is supported in any of a number of possible
ways. One support comprises a set of wheels 9, as illustrated in
FIGS. 1 and 2, which have the advantage that they enable enclosure
1 to be easily moved in service, and into and out of service, as
desired by the operator. Other ways to support enclosure 1 so that
it is movable include mounting it on a set of rails, or suspending
it from a set of rails. Alternatively, enclosure 1 can be suspended
from overhead structure such as a gantry.
[0042] As seen in FIG. 2, upper plate 10 is provided within
enclosure 1. It is located over the passageway within enclosure 1
that is occupied by a vehicle 11 when a vehicle (or part of a
vehicle) is present in enclosure 1. Upper plate 10 has a width 90%
to 120% of the width of the passageway (that is, the distance
across entrance 6 and exit 8) and extends in length (that is, in
the direction parallel to a line from the entrance of the enclosure
to the exit) that is 50% to 100% of the length of the passageway.
Upper plate 10 is gas-impermeable and may be constructed of sheet
metal. Upper plate 10 is located below top surface 2 of the
enclosure, thereby defining space 20, which is described further
below. Upper plate 10 is located above the uppermost poultry cage
on a vehicle 11 when a vehicle is in the passageway of enclosure 1,
and close enough to the uppermost poultry cage to provide
circulation of gaseous atmosphere through the cages 13 as described
below. The circulation and the resulting stunning of the poultry
are more effective as upper plate 10 is closer to the uppermost
poultry cage. Upper plate 10 can be fixed in position, or it can be
held by structure which permits the height of upper plate 10 to be
adjusted to accommodate the height of the uppermost poultry cage on
any given vehicle that has entered the enclosure 1.
[0043] Impeller 15 is located within enclosure 1. As shown,
impeller 15 can be situated on top of upper plate 10, but impeller
can be situated in either of the lateral spaces. Impeller 15 can be
a fan of conventional construction. It is powered by drive 16,
which can represent a source of electrical power for an electric
motor that rotates fan 15, or which can represent an electric motor
that turns a shaft which is connected by a belt to the shaft of fan
15. The axis of gas flow through impeller 15 is oriented so that
impeller 15 drives gaseous atmosphere through a flow circuit that
runs from space 20, into lateral space 21, then through a rank of
cages or through several (preferably 2 to 4) ranks of cages
adjacent to one another (i.e. side-by-side when seen from one side
of the vehicle), into lateral space 22, then again into space 20.
The arrows in FIG. 2 illustrate such a flow circuit.
[0044] FIG. 2 illustrates enclosure 1 when such a vehicle 11
carrying cages 13 is in the aforementioned passageway. Vehicle 11
can be any carrier that conforms to the description given herein,
such as a trailer on wheels or a skid on wheels or rails, but the
invention will be described with reference to a flatbed trailer.
Indeed, a significant advantage of the present invention is that it
can be practiced with trucks carrying caged poultry arriving from
the poultry farm at which the poultry was caged and then placed
onto the trucks, without requiring any unloading step prior to the
stunning or asphyxiation of the birds.
[0045] Vehicle 11 preferably includes a bottom plate 12 or platform
which is preferably gas-impermeable. Cages 13 either directly rest
on the bottom of the vehicle or are stacked onto cages that
directly rest on the bottom of the vehicle. To maximize efficient
processing of larger numbers of poultry, each rank of cages is
arrayed across the full width of the vehicle. However, fewer cages
13 than those shown in FIG. 2 can be processed in the practice of
the invention on a given vehicle-load of cages.
[0046] The cages 13 are of any design that can hold a chicken or
turkey and that permits gaseous atmosphere to pass from outside the
cage into and through the cage. The tops, bottoms and sides of the
cages are planar, to facilitate stacking them onto a vehicle such
as shown in FIG. 2.
[0047] Preferably, a barrier is provided that retards loss of the
atmosphere within the enclosure to the air outside the enclosure,
downwardly past the bottom edges of the sides 3, 4 and of the front
and rear panels 5 and 7. Such a barrier can be provided by
constructing the enclosure so that the lateral spaces 21 and 22 are
bounded on the bottom by rigid or flexible structure 31 and 32 that
closes off the bottom of each lateral space and terminates at or
near the vertical edges of the entrance 6 and exit 8.
[0048] Enclosure 1 also includes injector 17 which injects into the
atmosphere that is to circulate within the fluid flow circuit, a
gaseous component that renders the atmosphere capable of rendering
the poultry lethargic, and that is capable of rendering the poultry
unconscious or dead (when breathed in sufficient concentration for
a sufficient period of time) if that is the desired effect on the
poultry. If the desired effect on the poultry is to be caused by a
combination of more than one component, there can be one injector
that injects a mixture of the components, or there can be a
separate injector for each of the components that make up the
stunning atmosphere. The injector 17 (or the several injectors, if
necessary) inject into space 20 at a point upstream of impeller 15.
Each injector is connected to a source of the component being
injected (such as a storage tank) by a suitable feed line equipped
with flow control valving.
[0049] Probe 18 is provided that measures the composition of the
atmosphere within enclosure 1, or at least measures the
concentration within that atmosphere of the component or components
that are to have the desired effect (i.e., lethargy,
unconsciousness, or death) on the poultry. Probe 18 is connected by
conventional wiring to suitable electronic apparatus 24 by which an
operator or, preferably, an automated controller, can respond to
the measurement taken by the probe and adjust as necessary the
composition of the circulating atmosphere by, for instance, turning
on the flow of the component through the injector, turning off that
flow through the injector, adjusting the feed rate at which the
component is injected into the enclosure, and/or adjusting the
concentration of the component in the stream that is injected into
the enclosure. The feeding of a component or components via the
injector is automatically governed in response to measurements
taken by probe 18 of the concentration of the component. Controller
and associated equipment that perform the desired function, i.e.
determining the concentration of the component, and determining (as
a function of the concentration of the component in the flow
circuit and of the desired concentration in the flow circuit)
whether to adjust the flow of the component through the injector,
when to turn on and shut off that flow, and the like, is familiar
to people knowledgeable in the field of controlling gas
atmospheres.
[0050] Enclosure 1 also includes apparatus with which the
atmosphere within the flow circuit can be exhausted from the
enclosure after poultry has reached the desired state of being
rendered lethargic, unconscious or dead, and with which fresh air
can be fed into the enclosure. Suitable apparatus includes an
exhaust vent 26, which can be opened or closed as desired by the
operator, extending from the interior of the enclosure to the air
outside the enclosure, through which atmosphere within the
enclosure can be vented, and feed vent 27 through which ambient air
can be drawn into the enclosure. The functions of vents 26 and 27
can if desired be carried out by two separate vents or by one vent
that performs both functions.
[0051] An optional additional feature present in enclosure is
distributor 14, which is a device through which circulating
atmosphere passes and which provides that the mass flow rates at
which the atmosphere passes to the highest-elevated cage 13 (i.e.
closest to upper plate 7) and to the lowest cage (i.e. closest to
bottom plate 12) do not differ by more than 20% and preferably by
not more than 10%. That is, distributor 14 promotes uniform flow
rates of the gaseous atmosphere that passes through to the caged
poultry, unaffected by the height of a poultry cage above the
bottom plate 12. A distributor 14, if present, is situated in or at
the downstream face of lateral space 21, upstream of the rank or
ranks of cages to which circulating stunning atmosphere is to be
directed. Distributor 14 is a thin sheet of metal or plastic with a
large number of perforations through it. The sizes of the
perforations can be different at different locations in the
distributor, so that when gaseous atmosphere in lateral space 21 is
placed under pressure (such as by the action of impeller 15) the
atmosphere flow rate to all cages in the rank or ranks is
relatively uniform. The top edge of a distributor such as
distributor 14 extends from a side edge of upper plate 10, and it
should extend downward to the level of the lowest cage to which
stunning atmosphere is to be directed. Distributor 14 is of a
height and width sufficient to fill the space through which
circulating gas passes in the flow circuit. A distributor having
the same characteristics and functionality can be situated in or at
the upstream face of lateral space 22, downstream of the rank or
ranks of cages through which circulating atmosphere has flowed.
[0052] In one mode of operation, a vehicle 11 such as a truck
carrying or pulling a flat bed stacked with cages of poultry is
positioned in the enclosure as shown in FIG. 3. One rank of cages
and preferably 2 to 4 ranks of cages are within enclosure 1.
Preferably, when a vehicle's load of cages is first being subjected
to treatment by this invention, the first cages that are within the
enclosure are the cages closest to the front of the vehicle. If the
position of upper plate 10 is adjustable, then when carrier 11 has
entered enclosure 1 upper plate 10 (or a portion thereof, is moved
downward as close as possible to the top of a poultry cage while
still enabling the carrier to move without having the upper plate
dislodge any poultry cages.
[0053] In an optional embodiment, a vertical gas-impermeable sheet
is placed across the width of the vehicle, one on each side of the
rank or ranks of cages that are about to be exposed to the stunning
atmosphere. Each sheet should be as high as the stack of cages in
the rank or ranks, and each sheet should be as wide as the rank or
ranks are deep (that is, as seen across the width of vehicle 11).
The sheets improve efficiency by reducing the amount of circulating
stunning gas atmosphere that is lost from the front and rear walls
of the cages and that thus avoids being circulated in the desired
flow path described herein. Alternatively, the cargo area of the
vehicle can be constructed with a plurality of gas impermeable
panels extending vertically from the platform that is adapted to
contain ranks of open-air cages for the poultry across the entire
width of the platform. The gas impermeable panels operate to
partition the cargo area into a plurality of cargo sections and
limiting air flow between adjacent cargo sections. Such customized
vehicle is specifically designed to sealably engage with the
Enclosure 1 shown and described herein.
[0054] The efficiency and effectiveness of the circulating
atmosphere in bringing the poultry to the desired state of
lethargy, unconsciousness or death are increased by decreasing the
size of the gap between the face(s) of cages exposed to lateral
spaces 21 and 22, and the edges closest to the vehicle of the
surfaces that define lateral spaces 21 and 22 (i.e., in the case of
lateral space 21, the edges of front panel 5, rear panel 7, and
bottom structure 31). Satisfactory operation can be achieved even
with a gap of up to a few inches.
[0055] However, as another optional feature, a movable flexible
skirt can be provided that helps to channel the atmosphere that is
circulating within the aforementioned flow circuit from the lateral
space 21 to the cages into which the atmosphere is to be directed,
and out of such cages into lateral space 22. The upstream edges of
the upstream skirt and the downstream edges of downstream skirt are
secured to the adjacent side edges of upper plate 10, and to the
interior surfaces of front panel 5 and of rear panel 7, and to
either the interior surfaces of sides 3 and 4 or to the interior
surface of bottom structure 31 and 32. The downstream edge of the
upstream skirt and the upstream edge of the downstream skirt should
have a sufficient circumferential length that they each define an
opening (through which the circulating atmosphere flows) as tall
and as wide as the height and width of the rank or ranks of cages
through which the atmosphere is to be circulated. These edges can
if desired be joined to a gasket or other collar-like structure
having the length and width of the rank or ranks of cages to be
treated; using such a gasket or similar device facilitates handling
the skirt material. Each skirt should be of a length adequate to
extend from the areas at which it is attached to the structure of
the enclosure, to the rank or ranks of cages through which the
circulating atmosphere is to be directed. Suitable materials of
construction for the skirt include heavy cloth, plastic (such as
flexible polyethylene or polypropylene sheeting) or sections of
stiffer plastic material hinged together.
[0056] With the vehicle in position so that a rank or several ranks
of cages are within the enclosure, and with the aforementioned
apparatus 25 for exhausting atmosphere from the enclosure and for
feeding ambient air into the enclosure closed, skirts (if present)
are optionally positioned to help channel atmosphere flow through
the selected rank or ranks of cages, and one or more components are
injected via the aforementioned one or more injectors 17 to impart
to the atmosphere a composition which, when breathed by the poultry
in the selected rank or ranks of cages, will begin to bring the
poultry to the desired state i.e. lethargic, unconscious or dead.
The impeller should at this time be operating, to circulate the
component or components that are injected into the circulating
atmosphere.
[0057] As mentioned above, the injection of the component that is
to have the desired effect on the poultry can be governed
automatically by an automated controller into which has been
inputted the desired concentration of the component(s), and
optionally also the desired rate of increase of the concentration
of the component(s), that responds to measurements of the
concentration that are provided by probe 18 by injecting the
component(s) to bring about the desired concentration. It can be
advantageous to govern the injection of the component(s) in
response also to a desired rate of increase of the concentration,
as birds may exhibit convulsive behavior such as wing flapping and
other excessive movement if the concentration of the stunning
component increases too quickly.
[0058] Thus, the injection can occur without interruption
throughout a treatment cycle, or can occur intermittently. When the
composition of the atmosphere has reached the desired level,
injection can be discontinued but one may wish to continue
injection at a reduced flow rate to account for losses of the
atmosphere out of the flow circuit.
[0059] When the poultry being exposed to the circulating atmosphere
has reached the desired state of lethargy, unconsciousness or
lifelessness, injection of gas is discontinued. The atmosphere is
exhausted from the flow circuit, for instance through exhaust vent
26, and ambient air is drawn into the flow circuit, for instance
through feed vent 27. Continuing to operate the impeller during
this stage helps to exhaust the stunning atmosphere from the
enclosure and to draw in ambient air. The aforementioned optional
skirts, if present, can be retracted from the sides of the vehicle
11 at this time.
[0060] The vehicle and the enclosure are moved relative to each
other so that another rank or adjacent ranks of cages are in
position to be treated in the same sequence of steps just
described. The aforementioned exhausting of stunning atmosphere and
reintroduction of ambient air can be carried out while this
movement is occurring, although it is preferred that poultry next
to be treated is not exposed at the outset to a high concentration
of a stunning atmosphere. Preferably, ranks of cages should be
treated in a sequence from the cages closest to the front of the
vehicle, along the length of the vehicle in order, concluding with
the cages closest to the rear of the vehicle, to minimize excessive
movement of the vehicle and the enclosure, and to enable poultry in
the front most cages to be removed from the vehicle even while
cages remaining on the vehicle are being treated or are still
awaiting treatment.
[0061] Movement of the vehicle with respect to the enclosure can be
carried out in any of several different ways. The vehicle can be
driven, that is, moved or pulled under the power of the vehicle
itself just as though the vehicle were traveling under its own
power on the open road. Alternatively, the vehicle (the entire
truck, if it is a unitary vehicle or a cab unit pulling a trailer
with the caged poultry, or only the trailer carrying the caged
poultry) can be drawn into and through the enclosure by apparatus
such as a cable attached to the front of the vehicle by which the
vehicle is pulled through the enclosure, or by apparatus that
engages the underside of the vehicle with a drive mechanism that
draws the vehicle through the enclosure (such as the sort of
mechanism employed in automatic car washes).
[0062] In other alternatives of repositioning the enclosure to
circulate the stunning atmosphere through successive ranks of
cages, the enclosure can be moved relative to the ground and
relative to the vehicle, while the vehicle is stationary or while
the vehicle is moving relative to the ground. This alternative is
facilitated by mounting the enclosure on wheels or on rails so that
the enclosure can move relative to the ground. In the alternatives
in which the enclosure moves, the enclosure can be moved n a
direction from the front of the vehicle to the rear of the vehicle,
or in the opposite direction, or back and forth alternating between
those two directions.
[0063] The length of time that is necessary for a given atmosphere
to render the poultry lethargic, and the length of time necessary
to reach unconsciousness or death, will depend on the component or
components being used, and on the component concentration, and can
be determined experimentally.
[0064] Referring again to FIG. 3, when the vehicle begins to emerge
from the exit of the enclosure so that caged poultry which has been
rendered lethargic, unconscious or dead is accessible from outside
the enclosure, the poultry in the cage or cages that have become
accessible are removed from the vehicle at unloading area 40 for
further processing of the poultry. The poultry is removed from its
cages, either while the cages are still on the vehicle, or after
each cage has been removed from the vehicle to facilitate taking
the stunned bird out of its cage. Further processing typically will
include slaughtering the poultry, and dressing the carcass in any
desirable fashion. Caged poultry that has been rendered lethargic,
unconscious or dead by the treatment described herein are removed
from the front part of the vehicle while other poultry caged in the
more rearward areas of the vehicle are still undergoing stunning
within the enclosure or are awaiting treatment.
[0065] FIGS. 4 and 5 illustrate an alternate and preferred
apparatus useful in performing the above-described stunning
operations. While the apparatus in this preferred embodiment
differs from the above-described embodiment, the specific process
steps and operational controls are generally similar to those
described above with reference to FIGS. 1-3 and will therefore not
be repeated here.
[0066] As seen in FIGS. 4 and 5, the support structure 100 or
gantry, is the standing frame that supports the weight of all the
other major equipment. It includes the stationary columns 102 and
girders 104 as well as a moveable bridge 106 that carries the
stunning ducts 108. In the illustrated embodiment, the support
structure 100 is designed to be mounted only to the floor. However,
a moveable support structure is also specifically contemplated. The
upper portion of the support structure 100 may also be attached to
a wall or ceiling to stiffen the structure and reduce movement or
swaying caused by movement of the bridge 106 or when the bridge
reaches the mechanical stops 110.
[0067] The support structure 100 includes a plurality of stationary
columns 102 and a plurality of girders 104 which are bolted or
otherwise fixedly attached to the columns 102. The girders 104 also
act as the rails on which the bridge 106 rides. Mechanical stops
110 located near both ends 114, 116 of the girders 104 limit the
travel of the bridge 106. Additional support for the columns 102 is
provided by ties 118 between the ends of the girders 104.
[0068] The bridge 106 or carriage, aligns the stunning ducts 108 to
the trailer or other platform on which the poultry are situated.
The major components of the bridge 106 are the trucks 120, girders
122, and trolleys 124. The bridge girders 122 span the space
between the support structure 100 on both sides of the trailer. The
bridge girders 122 are connected with bridge ties 126 that provide
stability and form the girders 122 and trucks 120 into a single
unit. The illustrated bridge 106 also includes system two motorized
trucks and two non-motorized trucks. The motorized trucks are
preferably bolted to one of the bridge girders 122 while the
non-motorized trucks are bolted to the second bridge girder 122.
The trucks 120 are controllably operated to move the bridge 106 in
an axial direction along the length of the trailer. Each truck 120
includes a set of guide wheels 128 that allows the truck to be
guided by the rod 130 on the girders 104 associated with the
support structure 100.
[0069] Push-type trolleys 124 are moveably disposed along the
bottom flange of the bridge girders 122 and are also fixedly
attached to the stunning ducts 108. Thus, as the trolleys 124 move
along the bridge girder 122 that spans the width of the trailer,
the stunning ducts 108 can engage or disengage from the
trailer.
[0070] The stunning duct 108 acts as a shroud for the trailer and
together with the trailer platform completes the enclosure defining
the isolated atmosphere. Fans 132 operatively associated with the
stunning ducts 108 circulate the carbon dioxide or other stunning
gas through the cages on the trailer and bring in fresh air to
purge the carbon dioxide out of the enclosure. In the illustrated
embodiment of FIGS. 4 and 5, the stunning gas flows from the fan
side duct 134, through the trailer, to the non-fan side duct 136.
The stunning gas circulates back to the fan side duct 134 through
return hoses 138 disposed above the trailer at the top of the duct.
Each hose feeds a centrifugal fan 132 located in the fan side duct
134. To allow movement of the stunning ducts 108 to engage and
disengage from the trailer, a portion of the return hoses 138 are
preferably constructed of a flexible material. To reduce the sag in
the return hose 138 and the amount of hose to replace during
maintenance, the center portion 139 of the return hose 138 is
preferably constructed of a rigid PVC duct.
[0071] Carbon dioxide or other stunning gas is controllably
injected into the stunning duct by means of a pipe extending from a
source of stunning gas into the return hose 138 associated with
each stunning duct 108.
[0072] Rubber seals 140 along the faces of the stunning ducts 108
that come into contact with the trailer greatly reduce the amount
of carbon dioxide that leaks into the treatment area. The seals 140
are preferably attached with an adhesive.
[0073] The stunning ducts 108 are preferably constructed in a
modular fashion wherein each duct section 150 is generally sized to
correspond to the width of a single cage on the trailer. Each duct
section 150 is preferably tapered from the top 152 to the bottom
154 to facilitate flow distribution and to reduce the total volume
of the isolated atmosphere within the enclosure. Reducing the
volume of the enclosure in turn reduces the amount of carbon
dioxide required to operate the system. The duct sections are then
fastened together along with channels 156 to form the complete
duct.
[0074] The fan side duct 134 includes one or more duct sections 150
as described above, one or more stunning fans 132, a duct damper
and exhaust/air dampers. The operation of these components: (i)
forcibly circulates the stunning gas through the enclosure; (ii)
diverts or exhausts the flow of the stunning gas as required; and
(iii) introduces fresh ambient air into the enclosure as required.
The stunning fans 132 are direct-drive centrifugal plug fans that
are disposed in each duct section driven with a 10-hp motor. The
suction side of the stunning fan 132 is fed by a hose from the
non-fan side duct 136. The non-fan side duct 136 operates as the
return plenum for the forced air circulation.
[0075] Within each section 150 of the stunning duct 108 there is a
plurality of dampers (not shown) including a duct damper, an
exhaust damper, an air damper and a vent damper. In the closed
position, this duct damper blocks the flow from the stunning fan
from entering the isolated atmosphere in the enclosure. When used
with the opening of the exhaust and air dampers, the stunning gas
in the trailer is exhausted, and fresh air is brought into the
trailer. The duct damper is closed only when the stunning system is
operating in an air purge mode. At all other times, the duct damper
should be open to allow forced circulation of the isolated
atmosphere within the enclosure. The duct damper uses a pneumatic
rotary actuator to open and close in response to commands or inputs
from the control system 155. The exhaust damper exhausts the carbon
dioxide from the duct section 150 during an air purge operation.
The exhaust damper is connected to an exhaust manifold 160.
Concurrently, the air damper allows fresh ambient air into the duct
section during an air purge operation. The air damper is also
connected to a fresh air manifold 170. Like the duct damper, the
exhaust dampers and air dampers are controlled by pneumatic
actuators in response to commands or signals from the control
system 155. The vent dampers associated with the stunning duct 108
will vent the excess or displaced air to keep the stunning system
operating at or near atmospheric pressure. The vent damper is
preferably a weighted damper that opens with an increase of
pressure inside the stunning duct. Although each duct section 150
has a port available, not all ports are required to open in order
to vent the displaced gas.
[0076] Also illustrated in FIG. 4 is an exhaust blower, exhaust
ducting and floor pickups that establish a floor exhaust system
adapted to exhaust any carbon dioxide vapor that leaks out of or
remains in the truck after the stunning operation. The exhaust
system safely discharges the residual carbon dioxide vapors outside
the immediate work area.
[0077] Yet another alternate embodiment of the present system and
method of treating poultry involves initially off-loading the
poultry in their cages from the vehicle to a designated platform,
preferably stationary platform, where the apparatus similar to that
shown and described with reference to FIGS. 4 and 5 is employed to
shroud the cages or ranks of cages on the platform. After securing
the above described enclosure to the platform, which generally
isolates the atmosphere proximate the poultry, an oxygen-depleted
gaseous mixture is preferably introduced to the shrouded platform
to alter the composition of the isolated atmosphere and asphyxiate
the poultry or otherwise impart the desired effect on the poultry.
The specific apparatus, process steps, and operational controls are
generally similar to those described above with reference to FIGS.
1-5 and will not be repeated here.
[0078] The method and apparatus of the present invention provide
several advantages. The invention provides the advantages that
other techniques for stunning or asphyxiating the poultry provide,
such as reducing the difficulty and hazards faced by workers who
have to handle live, fully awake birds. But the invention provides
these at considerably less cost both in the cost of setting the
necessary apparatus and the cost of operating it. Also, the
apparatus can operate in a much smaller space than is required by
other stunning operations. In addition, the overall time required
to treat (stun) the cargo (e.g. a given quantity of poultry) is
reduced, compared to other stunning techniques, because of the
rapidity with which the invention works and because while some of
the poultry is still being stunned it is possible to be already
delivering stunned birds for further processing.
* * * * *