U.S. patent application number 10/360401 was filed with the patent office on 2004-08-12 for mosquito trapping apparatus utilizing cooled carbon dioxide.
This patent application is currently assigned to The Coleman Company, Inc.. Invention is credited to Mosher, Robert F. II.
Application Number | 20040154213 10/360401 |
Document ID | / |
Family ID | 32824002 |
Filed Date | 2004-08-12 |
United States Patent
Application |
20040154213 |
Kind Code |
A1 |
Mosher, Robert F. II |
August 12, 2004 |
MOSQUITO TRAPPING APPARATUS UTILIZING COOLED CARBON DIOXIDE
Abstract
An insect trap that utilizes a combustion chamber to produce
carbon dioxide for an attractant. Combustion gasses from the
combustion chamber are cooled in a conduit for the trap inlet.
Thus, a single fan may be used for both drawing insects into the
insect trap and for cooling the combustion chamber. Combustion
gasses, after being cooled by the flow of air through the conduit
connected to the trap inlet, may be further cooled by a cooling
system, such as a thermoelectric device. As such, the insect trap
of the present invention may be used to produce carbon dioxide, via
combustion, at temperatures at or below ambient temperature.
Inventors: |
Mosher, Robert F. II;
(Wichita, KS) |
Correspondence
Address: |
LEYDIG, VOIT & MAYER, LTD.
(SEATTLE OFFICE)
TWO PRUDENTIAL PLAZA
SUITE 4900
CHICAGO
IL
60601-6780
US
|
Assignee: |
The Coleman Company, Inc.
Wichita
KS
|
Family ID: |
32824002 |
Appl. No.: |
10/360401 |
Filed: |
February 7, 2003 |
Current U.S.
Class: |
43/107 |
Current CPC
Class: |
A01M 1/06 20130101; A01M
1/023 20130101; A01M 2200/012 20130101 |
Class at
Publication: |
043/107 |
International
Class: |
A01M 001/20 |
Claims
What is claimed is:
1. An insect trap comprising: a conduit for the entry of insects,
and including a trap entry; a fan for drawing air through the
conduit; a combustion chamber having an outlet in fluid
communication with an attractant outlet, the combustion chamber
being arranged and configured so air drawn through the conduit by
the fan cools the combustion chamber.
2. The insect trap of claim 1, further comprising a heat exchanger
mounted on the combustion chamber and arranged to contact the air
drawn by the fan.
3. The insect trap of claim 2, wherein the heat exchanger comprises
a central chamber and outer fins extending from the central
chamber, the outer fins being in contact with air flowing through
the trap inlet via the fan.
4. The insect trap of claim 3, further comprising a combustion tube
mounted at least partly within the heat exchanger and inside the
central chamber.
5. The insect trap of claim 4, wherein the heat exchanger further
comprises inner fins extending inward from the central chamber and
abutting the combustion tube.
6. The insect trap of claim 4, further comprising a fan in the
combustion tube for directing air into the central chamber.
7. The insect trap of claim 6, further comprising a structure for
mixing air from the fan with combusted gasses formed within the
combustion tube.
8. The insect trap of claim 1, further comprising a cooling device
mounted between the outlet of the combustion chamber and the
attractant outlet, the cooling device being configured to cool
exhaust gasses from the combustion chamber.
9. The insect trap of claim 8, wherein the cooling device is
configured to cool exhaust gasses to ambient temperature or
below.
10. The insect trap of claim 8, wherein the cooling device
comprises a thermoelectric device.
11. The insect trap of claim 10, wherein the thermoelectric device
comprises a hot sink and a cold sink, and wherein the cold sink is
arranged to contact the exhaust gases.
12. The insect trap of claim 1, wherein the combustion chamber is
mounted at least partly within the conduit.
13. The insect trap of claim 12, further comprising a heat
exchanger mounted between the combustion chamber and the conduit,
the heat exchanger being arranged to contact the air drawn by the
fan.
14. The insect trap of claim 13, wherein the heat exchanger
comprises a central cylinder defining a central chamber and outer
fins extending from the central cylinder, the outer fins being in
contact with air flowing through the trap inlet via the fan, and
being in contact with an interior wall of the conduit.
15. The insect trap of claim 14, further comprising a combustion
tube mounted at least partly within the heat exchanger and inside
the central chamber.
16. The insect trap of claim 15, wherein the heat exchanger further
comprises inner fins extending inward from the central chamber and
abutting the combustion tube.
17. The insect trap of claim 15, further comprising a fan in the
combustion tube for directing air into the central chamber.
18. The insect trap of claim 17, further comprising a structure for
mixing air from the fan with combusted gasses formed within the
combustion tube.
19. An insect trap comprising: a combustion chamber for producing
carbon dioxiode and having an outlet in fluid communication with an
attractant outlet; and a cooling device mounted between the outlet
of the combustion chamber and the attractant outlet, the cooling
device being configured to cool exhaust gasses from the combustion
chamber to ambient temperature or below.
20. The insect trap of claim 19, wherein the cooling device
comprises a thermoelectric device.
21. The insect trap of claim 20, wherein the thermoelectric device
comprises a hot sink and a cold sink, and wherein the cold sink is
arranged to contact the exhaust gases.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to insect traps, and more
particularly to devices for attracting, and trapping or killing,
mosquitoes and other biting insects.
BACKGROUND OF THE INVENTION
[0002] Biting insects, such as mosquitoes and flies, can be an
annoying, serious problem in man's domain. They interfere with work
and spoil hours of leisure time. Their attacks on farm animals can
cause loss of weight and decreased milk production. Worldwide,
mosquito-borne diseases kill more people than any other single
factor. Mosquitoes can be carriers of malaria, yellow fever, and
dengue fever in humans. In the United States, mosquitoes spread
several types of encephalitis, including the West Nile virus. They
also transmit heart worms to cats and dogs.
[0003] People are not the primary blood hosts for mosquitoes and
biting insects, especially in temperate climates. The major
mosquito pests in the southeastern United States seem to prefer the
host-odor of small herbivorous (vegetarian) mammals, such as
rabbits, or birds. Mosquitoes that carry encephalitis seem to
prefer avian (bird) blood hosts. These mosquitoes bite people when
they get the chance, but they are better at tracking the scent of
animals that are most abundant in their habitat.
[0004] People have tried a number of different methods to rid
themselves of mosquitoes and other biting insects. One method that
is often utilized is spraying or applying chemical insecticides.
Although many chemicals work well to kill or repel mosquitoes, the
chemicals often have a deleterious effect on the environment,
including, but not limited to, killing beneficial insects. In
addition, chemical insecticides are effective only for a limited
amount of time, and thus must be continuously sprayed. Moreover,
many types of mosquitoes and biting insects are capable of
developing resistance to the chemical pesticides in a few
generations (which may only take a few months for mosquitoes), and
in the long run, that adaptation makes the species stronger.
[0005] Another method used to combat mosquitoes is bug zappers. In
general, a bug zapper includes a fluorescent light source
surrounded by an electrified grid. The theory behind these devices
is that the mosquitoes are attracted to the light, and, upon flying
to the light, will be electrocuted by the grid. In actuality,
however, the bug zappers kill beneficial insects, and attract
mosquitoes but does not kill them in significant numbers.
[0006] Citronella candles and smoking coils are often used to repel
mosquitoes and other insects. However, research has shown that, in
general, an individual must stand within the smoky plume of the
citronella to be protected. This, of course, is not desirable.
Moreover, even when standing in the plume, citronella is only
partly effective in reducing the probability of a mosquito bite.
Encouraging natural predation of insects by setting up bird or bat
houses in the backyard has also been unsuccessful in reducing local
mosquito populations.
[0007] Recently, significant research and effort have been expended
to develop devices that attract and trap or kill mosquitoes. In
general, these devices attempt to replicate the mosquito-attracting
attributes of a typical blood host, such as a rabbit or a bird.
Mosquitoes locate blood hosts by scent, sight and heat. From 100
feet away (30 meters) mosquitoes can smell a potential blood host's
scent, especially the carbon dioxide (CO2) the blood host exhales.
Similarly, biting flies can smell their prey from 300 feet (100
meters) away. Because CO2 is present in the atmosphere (plants take
in CO2 and give off oxygen), mosquitoes respond to
higher-than-normal concentrations, especially when the CO2 is mixed
with host-odor. They follow a blood host's scent upwind, and can
see a target at a distance of about 30 feet (10 meters). Devices
that try to simulate a mosquito host thus may include, for example,
a source of carbon dioxide, a source of octenol (an alcohol that is
given off by mammalian blood hosts), and/or a heat source.
[0008] One such device is sold under the trademark "MOSQUITO
MAGNET" and is described in U.S. Pat. No. 6,145,243 to Wigton et
al. The MOSQUITO MAGNET apparatus is an insect trapping device that
generates its own insect attractants of carbon dioxide (CO2), heat,
and water vapor through catalytic conversion of a hydrocarbon fuel
in a combustion chamber. The hot insect attractants generated in
the combustion chamber are diluted and cooled to a temperature
above ambient temperature and below about 115 degrees Fahrenheit
(F) by mixing with air, and the mixture is exhausted downward
through an exhaust tube. A counterflow of outside air is drawn into
the trap though a suction tube that concentrically surrounds the
exhaust tube. Biting insects are sucked into the suction tube and
are captured in a porous, disposable bag connected to the other end
of the suction tube. Additional chemical attractants may be used
with the device to make the trap even more effective.
[0009] Although the MOSQUITO MAGNET device works well for its
intended purpose, due to its high suggested retail price ($500 to
$1300, depending upon the model), it is far out of reach of the
ordinary consumer. Thus, few people would actually purchase the
MOSQUITO MAGNET, even if they have a pressing need for mosquito
control.
[0010] Another device that has been used in the past for trapping
mosquitoes is the Center for Disease Control (CDC) light trap. The
light trap includes a motor driven rotary fan to move attracted
insects down into a holding container suspended beneath the trap,
and a light source. More recently, the CDC light trap has been used
with a source of carbon dioxide, usually dry ice. Dry ice produces
carbon dioxide at a temperature below ambient, and works
particularly well for attracting mosquitoes and other biting
insects. Although a CDC light trap utilizing dry ice works well for
its intended purpose, the handling and use of dry ice can be
difficult and expensive.
SUMMARY OF THE INVENTION
[0011] The present invention provides an insect trap that utilizes
a combustion chamber to produce carbon dioxide for an attractant.
Combustion gasses from the combustion chamber are cooled in a
conduit for the trap inlet. Thus, a single fan may be used for both
drawing insects into the insect trap and for cooling the combustion
chamber.
[0012] In accordance with an aspect of the present invention,
combustion gasses, after being cooled by the flow of air through
the conduit connected to the trap inlet, may be further cooled by a
cooling system, such as a thermoelectric device. As such, the
insect trap of the present invention may be used to produce carbon
dioxide, via combustion, at temperatures at or below ambient
temperature.
[0013] Other advantages will become apparent from the following
detailed description when taken in conjunction with the drawings,
in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic representation of an insect trap in
accordance with the present invention;
[0015] FIG. 2 is a side perspective view of a combustion gas
cooling portion the insect trap of Claim 1;
[0016] FIG. 3 is an exploded side perspective view showing the
combustion gas cooling portion of FIG. 2; and
[0017] FIG. 4 is an exploded side perspective view showing the
combustion gas cooling portion of FIG. 2, in a further state of
disassembly, and with parts removed to show detail.
DETAILED DESCRIPTION
[0018] In the following description, various aspects of the present
invention will be described. For purposes of explanation, specific
configurations and details are set forth in order to provide a
thorough understanding of the present invention. However, it will
also be apparent to one skilled in the art that the present
invention may be practiced without the specific details.
Furthermore, well-known features may be omitted or simplified in
order not to obscure the present invention. In addition, to the
extent that orientations of the invention are described, such as
"top," "bottom," "front," "back," and the like, the orientations
are to aid the reader in understanding the invention, and are not
meant to be limiting.
[0019] At the outset, it is important to note a few characteristics
of mosquitoes and flying insects. Typically, biting insects are
attracted by the odor of kairomones, which are chemicals given off
by blood hosts and which are attractants to biting insects.
Kairomones include carbon dioxide exhaled by both mammalian and
avian blood hosts and octenol, an alcohol which is given off by
mammalian blood hosts. Biting insects locate a blood host by
tracking the odor plume created by the blood host. A mixture of
carbon dioxide and octenol is particularly attractive to insects
seeking mammalian blood hosts. The present invention provides a
relatively inexpensive way to provide cooled carbon dioxide for a
mosquito trap, and specifically may provide carbon dioxide at or
below ambient.
[0020] Turning now to the drawings, in which like reference
numerals represent like parts throughout the several views, FIG. 1
shows a schematic diagram of an insect trap 10 incorporating the
present invention. The insect trap 10 includes a trap inlet 12 at
an end of a trap conduit 14. In accordance with one embodiment of
the present invention, a combustion chamber 16 is mounted in the
trap conduit 14, and is cooled by air flow through the trap
conduit.
[0021] Briefly described, combustion occurs in the combustion
chamber 16, and the combustion gasses from the combustion process
are cooled by air flowing through the trap conduit 14. The cooled
air flows from the combustion chamber 16 into a cooling chamber 18,
and out of exhaust outlets 20. The cooling of the combustion
chamber 16 by the air flowing the trap conduit 14, along with the
cooling by the cooling chamber 18, causes the gasses exiting from
the exhaust outlets 20 to be at or below ambient temperature.
[0022] The invention has particular use for producing cooled carbon
dioxide gasses for use in a mosquito trap. To this end, the trap
inlet 12 may serve as an inlet for receiving mosquitoes and other
biting insects that are attracted by the exhaust plume exiting the
exhaust outlets 20. Thus, in accordance with one aspect of the
present invention, the exhaust outlets preferably route the cooled,
combusted gasses adjacent to the trap inlet 12. Mosquitoes
attracted to the plume are drawn into the trap inlet 12.
[0023] To capture mosquitoes and/or biting insects, the insect trap
10 may include a specimen bag 22 at some position along the length
of the trap conduit 14 for catching insects as they are drawn
through the trap conduit 14. To this end, a fan 24 or a similar
device that is capable of drawing air through the trap conduit 14
is provided within, or is otherwise associated with, the trap
conduit 14 so as to draw air through the trap conduit 14.
[0024] In one embodiment, the fan 24 may be capable of drawing, for
example, 235 cubit feet per minute of air through the trap conduit
14. This significant draw of air into the trap inlet 12 is
sufficient to draw mosquitoes and other biting insects into the
trap conduit 14 when the insects approach the trap inlet 12.
[0025] In accordance with one aspect of the present invention, the
combustion chamber 16 is mounted so that the combustion chamber,
and gasses produced in the combustion chamber, are cooled by air
flowing from the trap conduit 14. In the embodiment shown, the
combustion chamber 16 is located in the trap conduit, but air may
alternatively be routed into contact with combustion chamber, such
as against the side of the combustion chamber, or through a portion
of the combustion chamber. To this end, to the extent that the trap
conduit 14 is discussed herein as routing air over, through, in
contact with, or around the combustion chamber, the air flow may be
any of these. Similarly, the trap conduit 14 may not be a single
conduit, but instead may be any structure that directs at least
some air from the trap inlet into contact with the combustion
chamber.
[0026] In the embodiment shown in the drawings, the combustion
chamber 16 includes a burner tube 30. Details of the burner tube 30
are best shown in FIG. 4. The burner tube 30 includes a right angel
bend at its lower end, with first and second fans 32, 34 at
opposite ends of the right angle. The fans 32, 34 are both arranged
so that they may draw air into the burner tube 30, and in one
embodiment, each produces an air flow of seven to ten cubic feet
per minute. As an alternative to the two fans shown, a single fan
may be used to draw air into and through the burner tube 30.
[0027] A burner 36 is mounted centrally in the burner tube 30.
Preferably, the burner is spaced from the inner side walls of the
burner tube 30. The burner 36 includes a fuel inlet 38 leading to
typical components for a burner assembly, for example, such as is
used for camping stoves or camping lanterns. Because such
components are well known, they are omitted from the drawings in
order not to obscure the present invention. However, as an example,
the fuel inlet 38 may be connected to a regulator (not shown) for
lowering the pressure from a propane tank or other propane source.
Although described with reference to a propane burner, the
combustion chamber 16 may utilize other fuels for combustion,
including, but not limited to, kerosene, gasoline, and other
liquid, solid, or gaseous fuels.
[0028] An electrode 48 (FIG. 4) may be included for starting a
flame in the burner 36 in a method known in the camp stove art.
Alternatively, manual lighting of the burner 36 may be implemented,
but such a system is not as convenient as a burner including an
automatic starter such as the electrode 48.
[0029] In the embodiment shown in the drawings, the fans 32, 34
draw air through the bottom of the burner tube 30 into contact with
the bottom of the burner 36 and around the burner 36 to bypass the
burner 36. Air entering the burner 36 is used in the combustion
process. Air flowing around the burner 36 is not combusted.
Preferably, in accordance with one aspect of the present invention,
a structure is provided within the burner tube 30 or closely
associated therewith that mixes the combusted gasses from the
burner 36 with the air flowing around the burner 36. In the
embodiment shown in the drawings, this mixing is provided by a
circular pattern of fixed fan blades 40 (FIG. 4) positioned across
the top of the burner tube 30. However, if desired, other
structures may be used.
[0030] A cylindrical heat exchanger 50 is mounted on the outside of
the burner tube 30. The cylindrical heat exchanger 50 is preferably
formed of a thermally conductive material. In the embodiment shown
in the drawings, the cylindrical heat exchanger 50 includes a
central cylinder 52 having outer fins 54 extending outwardly
therefrom. Inner fins 56 extend inward from the central cylinder 52
and are spaced from one another so as to form a void. The void is
sized and arranged so as to receive the burner tube 30. The burner
tube 30 preferably fits within the void so that the top of the
burner tube 30 is spaced from the top of the cylindrical heat
exchanger 50, the function of which is described below. If desired,
the burner tube 30 may alternatively be integrally formed with the
heat exchanger 50.
[0031] In the embodiment shown in the drawings, a series of bosses
58 are located around the top edge of the central cylinder 52. The
bosses are for receiving fasteners 59 for the attachment of a top
plate 60. The top plate 60 encloses the top portion of the central
cylinder 52, and with the central cylinder defines a central
chamber in the heat exchanger. The central chamber may be arranged
in alternate ways. Although shown as a cylinder with a flat top in
the drawings, the central chamber may take any shape and may be
formed from one or more pieces. The top portion of the burner tube
30 is located within the central chamber. Although shown as being
attached by the fasteners 59, the top plate 60 may be one piece
with the cylindrical heat exchanger 50, or may be attached in
another suitable manner, such as welding.
[0032] A series of flanges 62 extend outward from a bottom portion
of the cylindrical heat exchanger 50. As can be seen in FIG. 4, the
electrode 48 may extend out of the side of the cylindrical heat
exchanger 50.
[0033] As shown in FIGS. 3 and 4, to assemble the combustion
chamber 16, the burner tube 30 is inserted upward into the void
between the inner flanges 56 of the cylindrical heat exchanger 50.
The cylindrical heat exchanger 50 is then inserted into the trap
conduit 14. Preferably, each of these pieces fits tightly into the
next, so that the outer edges of the outer fins 54 of the heat
exchanger 50 engage the inner walls of the trap conduit 14, and the
burner tube 30 abuts the inner edge of each of the inner fins 56.
In the shown embodiment, the trap conduit 14 is split into two
different pieces, with the fan 24 being situated between the two
pieces. If desired, the trap conduit 14 may be formed as a single
piece, or as multiple pieces, or may be any structure that provides
fluid communication between the trap inlet 12 and the combustion
chamber 16.
[0034] When the cylindrical heat exchanger 50 is inserted into the
trap conduit 14, the bottom edge of the trap conduit 14 rests
against the flanges 62. Thus, the bottom portion of the cylindrical
heat exchanger 50 extends out of the bottom of the trap conduit
14.
[0035] As can best be seen in FIG. 1, the cooling chamber 18 is
connected to the bottom of the cylindrical heat exchanger 50 and is
in fluid communication with the central chamber of the cylindrical
heat exchanger 50. Thus, the cooling chamber 18 is in fluid
communication with the inside of the burner tube 30. The cooling
chamber 18 includes a manifold 68 that extends from the cylindrical
heat exchanger 50 to the exhaust outlets 20.
[0036] A cooling device is located within the cooling chamber 18.
In the shown embodiment, the cooling device is a thermoelectric
device 70. However, the cooling device may alternatively be any
device that is capable of removing heat from the cooling chamber
18, such as a Stirling cooler, a refrigeration unit, or other
structures designed to remove heat.
[0037] For the thermoelectric device 70, one or more thermoelectric
coolers 72 (FIG. 4, well known in the industry) are mounted between
a cold side sink 74 and a hot side sink 76. As can be seen in FIG.
3, the cold side sink 74 is mounted inside the cooling chamber 18,
and the hot side sink 76 extends outside of the cooling chamber 18.
A number of power ports 78 are included on the side of the manifold
68 for attaching a power supply (not shown) to the thermoelectric
coolers 72.
[0038] For the embodiment shown in the drawings, six exhaust
outlets 20 are included on the end of the manifold 68. Any number
of exhaust outlets may be used, and exhaust from the exhaust
outlets 20 is preferably routed adjacent to the trap inlet 12. This
routing is not shown in the drawings, but may be provided by
appropriate conduits. By routing the cooled exhaust gases adjacent
to the trap inlet 12, mosquitoes and other biting insects may be
attracted by the exhaust, and may be sucked into the trap inlet 12.
A drip tube 80 is included on the bottom of the manifold 68 for
allowing condensation from the exhaust to drip out of the manifold
68.
[0039] In operation, the fans 24, 34 and 32 are turned on, and the
gas supplied to the burner 36 via the fuel inlet 38. The electrode
48 is sparked, causing a flame to burn in the burner 36. Air may be
drawn into the burner tube 30 via air inlets 82, or the air may be
supplied solely from the fans 32 and 34. In addition, if desired,
octenol or another insect attractant may be introduced into the
burner tube 30 and mixed with the combustion gases.
[0040] Combustion by the burner 36 creates carbon dioxide, which
flows upward through the burner tube 30. The air flow from the fans
32, 34 flows around the burner 36 and the combusted gasses of the
burner. Because this air stream is under some pressure, and the
combustion gasses are initially at high heat and tend to rise,
there is little mixing of the air flowing around the burner and the
combustion gases until the air flow and the combusted gasses reach
the fan blades 40. These fan blades cause turbulence in the air
flow, and mix the combusted gasses with the air flow from the fans
32, 34. The air flow then reaches the top plate 60 and is forced
down between the inner fins 56 and out into the manifold 68.
[0041] Air flowing through the trap conduit 14 enters the trap
inlet 12 and flows through the specimen bag 22 and through the fan
24. From there, the air has only one place to travel, and that is
downward through the outer fins 54. This air flow causes a cooling
of the outer fins 54. This cooling effect is transferred to the
rest of the cylindrical heat exchanger 50, because, as stated
above, the cylindrical heat exchanger 50 is preferably formed of a
thermally conductive material. The cooling by the air is
transmitted to the burning tube 30 via the inner fins 56. To this
end, the inner fins 56 may be configured (e.g., chamfered) as
desired so as to maximize heat removal from the central chamber and
the burner tube.
[0042] Thus, the air flow through the trap conduit 14 cools the
combusted air leaving the burner tube 30 and flowing to the
manifold 68. In one embodiment, this cooling effect, along with the
cooling of the combusted gasses by the dilution with the air
flowing from the fans 32, 34, causes air entering the manifold 68
to be approximately twenty degrees Fahrenheit (F) above
ambient.
[0043] The cooling device (e.g., the thermoelectric device 70),
further cools the combusted gasses before they reach the exhaust
outlets 20. In the shown embodiment, the combusted gasses are
cooled to slightly below ambient. This temperature of carbon
dioxide has been found to be beneficial in attracting biting
insects and mosquitoes.
[0044] The concepts of the invention may be used as shown in the
drawings, or the cooling chamber 18 and the cylindrical heat
exchanger 50 may be used without the other. For example, the burner
tube 30 and the cylindrical heat exchanger 50 may be used with the
trap conduit 14, without the use of the cooling chamber 18, so as
to provide cooled carbon dioxide for a mosquito and biting insect
trap. In addition, combustion gasses may be routed through a
cooling chamber, such as the cooling chamber 18, and may be cooled
by the cooling device (e.g., the thermoelectric device 70), without
being first cooled by the air flowing through the trap conduit 14.
However, the combination of the devices works particularly well in
providing cooled combustion gasses with an apparatus of very little
cost.
[0045] The present invention is particularly useful in that it
generates carbon dioxide through a combustion process, which is a
relatively inexpensive and virtually maintenance free manner of
producing the carbon dioxide. In addition, the present invention
utilizes an existing air flow--the flow through the trap conduit
14--to cool that carbon dioxide to a temperature where it is useful
for attracting mosquitoes and other biting insects.
[0046] The cooling device (e.g., the thermoelectric device 70) is
useful in that it may be used to closely set an exhaust temperature
for the combustion gases. If desired, the cooling device may be
used in conjunction with a temperature sensor so that exhaust
temperatures may be more precisely controlled.
[0047] Other variations are within the spirit of the present
invention. Thus, while the invention is susceptible to various
modifications and alternative constructions, a certain illustrated
embodiment thereof is shown in the drawings and has been described
above in detail. It should be understood, however, that there is no
intention to limit the invention to the specific form or forms
disclosed, but on the contrary, the intention is to cover all
modifications, alternative constructions, and equivalents falling
within the spirit and scope of the invention, as defined in the
appended claims.
* * * * *