U.S. patent application number 14/711524 was filed with the patent office on 2015-08-27 for heatable enclosure for pest eradication.
The applicant listed for this patent is Buzzkill, LLC. Invention is credited to Michael David Lindsey.
Application Number | 20150237843 14/711524 |
Document ID | / |
Family ID | 47884069 |
Filed Date | 2015-08-27 |
United States Patent
Application |
20150237843 |
Kind Code |
A1 |
Lindsey; Michael David |
August 27, 2015 |
HEATABLE ENCLOSURE FOR PEST ERADICATION
Abstract
Disclosed are heatable enclosures useful in treating materials
for eradication of pests. Specifically, a heating layer which can
be fitted or retrofitted into a numerous and wide variety of
containers and enclosures, such as suitcases, boxes, trucks and
trailers, which are operable to heat the enclosed space of the
container to treat heatable materials over a period of time to
eradicate pests. Heating films can be utilized that are inexpensive
and lightweight.
Inventors: |
Lindsey; Michael David;
(Fort Collins, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Buzzkill, LLC |
Fort Collins |
CO |
US |
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|
Family ID: |
47884069 |
Appl. No.: |
14/711524 |
Filed: |
May 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13232156 |
Sep 14, 2011 |
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14711524 |
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61403411 |
Sep 14, 2010 |
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Current U.S.
Class: |
43/132.1 |
Current CPC
Class: |
A01M 19/00 20130101;
A01M 1/22 20130101; A01M 1/2094 20130101; A01M 1/20 20130101 |
International
Class: |
A01M 1/20 20060101
A01M001/20; A01M 19/00 20060101 A01M019/00; A01M 1/22 20060101
A01M001/22 |
Claims
1. A system for killing pests on heatable materials comprising: a
enclosure including an exterior carton that is configured to
receive said heatable materials, said enclosure having an exterior
surface and an interior surface and being formed of four side wall
portions that surrounds an interior space of said enclosure, a
bottom portion and a lid portion; a plurality of heating films that
generates infrared radiation comprising a resistive material that
is disposed on a substrate, said heating films disposed in said
interior space along each of said four side wall portions; four
insulating walls, an insulating floor and an insulating lid
configured for placement into said box enclosure and disposed
between said heating films and said wall portions, said bottom
portion and said lid portion; and a control device, that is
operatively coupled to said heating films, that controls current
flowing through said heating films so that said infrared radiation
penetrates and heats said heatable materials when disposed in said
enclosure to a sufficiently high temperature, for a sufficiently
long period, to kill said pests.
2. The system of claim 1 wherein said resistive material includes
resistive wire heating elements.
3. The system of claim 1 wherein said control device comprises: at
least one temperature sensor disposed in said box enclosure that
detects temperatures in an interior portion of said enclosure and
generates temperature signals indicative of said temperatures; a
controller that receives said signals and controls said current
flowing through said heating films.
4. The system of claim 1 wherein said control device comprises a
bi-metallic switch coupled to control said current flowing through
said heating films.
5. The system of claim 1 wherein said plurality of heating films is
retrofit into said interior space of said enclosure.
6. The system of claim 1 wherein said plurality of heating films
are form fit integral components of said enclosure.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present patent application is a continuation of U.S.
patent application Ser. No. 13/232,156, filed Sep. 14, 2011, which
application is based upon and claims the benefit of U.S.
Provisional Patent Application Ser. No. 61/403,411 filed Sep. 14,
2010. The above-identified applications are hereby incorporated
herein by reference in their entirety.
BACKGROUND
[0002] Pest and insect damage to materials, fabrics, and garments
is a growing problem. As a non-limiting example, insect damage to
textiles in the United States is estimated at $200 million
annually. Fabric and garment insect infestations are making a
comeback because most of the insecticides formerly used to control
insects and pests, such as dieldrin and
dichlorodiphenyltrichloroethane ("DDT"), have been banned.
[0003] Accordingly, as people travel, or as containers are shipped
from location to location, there is a growing incidence of pest or
insect infestation of garments transported in luggage and materials
shipped in containers. For example, bed bugs may be found in many
hotels, motels, homes, or other accommodations, even in highly
sanitary conditions. During the day, nocturnal insects, such as
bedbugs, disappear in crevices associated with mattresses, box
springs, sheets, upholstery, garments, clothes, pillows, towels, or
the like. Even when these materials are examined, it is common for
these insects, or the eggs of these insects, to go undetected and
packed with garments and transported in luggage.
SUMMARY OF THE INVENTION
[0004] An embodiment of the present invention may therefore
comprise a system for killing pests on heatable materials
comprising: an enclosure that is adapted to receive the heatable
materials, the enclosure having an exterior surface and an interior
surface that surrounds an interior space of the enclosure; a
heating film that generates infrared radiation comprising a
resistive material that is disposed on a substrate, the heating
film disposed in the interior space of the enclosure; an insulating
layer disposed between the heating film and the interior surface of
the enclosure; and a control device, that is operatively coupled to
the heating film, that controls current flowing through the heating
film so that the infrared radiation penetrates and heats the
heatable materials disposed in the enclosure to a sufficiently high
temperature, for a sufficiently long period, to kill the pests.
[0005] An embodiment of the present invention may further comprise
a method of killing pests on heat treatable materials comprising:
providing an enclosure that is adapted to receive the heatable
materials, the enclosure having an exterior surface and an interior
surface that surrounds an interior space of the enclosure;
providing a heating film that generates infrared radiation
comprising a resistive material that is disposed on a substrate,
the heating film disposed in the interior space of the enclosure;
providing an insulating layer disposed between the heating film and
the interior surface of the enclosure; and providing a control
device that is operatively coupled to the heating film, that
controls current flowing through the heating film so that the
infrared radiation penetrates and heats the heatable materials
disposed in the enclosure to a sufficiently high temperature for a
sufficiently long period to kill the pests.
[0006] An embodiment of the present invention may further comprise
a system for killing pests on heatable materials comprising: an
enclosure that is adapted to receive the heatable materials, the
enclosure having an exterior surface and an interior surface that
surrounds an interior space of the enclosure; a resistive wire
heating layer that generates heat by Joule heating comprising a
resistive material that is disposed on a substrate, the heating
layer disposed in the interior space on multiple surfaces of the
enclosure; an insulating layer disposed between the heating film
and the interior surface of the enclosure; and a control device,
that is operatively coupled to the heating layer, that controls
current flowing through the heating layer so that the infrared
radiation penetrates and heats the heatable materials disposed in
the enclosure to a sufficiently high temperature, for a
sufficiently long period, to kill the pests.
[0007] An embodiment of the present invention may further comprise
a method of killing pests on heat treatable materials comprising:
providing an enclosure that is adapted to receive the heatable
materials, the enclosure having an exterior surface and an interior
surface that surrounds an interior space of the enclosure;
providing a resistive wire heating layer that generates heat by
Joule heating comprising a resistive material that is disposed on a
substrate, the heating film disposed in the interior space on
multiple surfaces of the enclosure; providing an insulating layer
disposed between the heating layer and the interior surface of the
enclosure; and providing a control device that is operatively
coupled to the heating layer, that controls current flowing through
the heating layer so that the heat penetrates and heats the
heatable materials disposed in the enclosure to a sufficiently high
temperature for a sufficiently long period to kill the pests.
A BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an illustration of an embodiment of a heatable
enclosure for pest eradication.
[0009] FIG. 2 is an end view of the embodiment of the heatable
enclosure of FIG. 1.
[0010] FIG. 3 is a left side view of the embodiment of the heatable
enclosure of FIG. 1.
[0011] FIG. 4 is a top view of the embodiment of the heatable
enclosure of FIG. 1 having a releasably sealable access element in
a closed condition.
[0012] FIG. 5 is a right side view of the embodiment of the
heatable enclosure of FIG. 1.
[0013] FIG. 6 is a top view of the embodiment of the heatable
enclosure of FIG. 1 having a releasably sealable access element in
ah open condition.
[0014] FIG. 7 is an opposite end view of the embodiment of the
heatable enclosure of FIG. 1.
[0015] FIG. 8 is a cross section of the embodiment of FIG. 1.
[0016] FIG. 9 is an isometric, enlarged view of the heatable
enclosure user interface utilized in the embodiment of the heatable
enclosure illustrated in FIG. 1.
[0017] FIG. 10 is a flow diagram of an embodiment of a method of
using a heatable enclosure.
[0018] FIG. 11 is an exploded view of another embodiment of a
heatable enclosure.
[0019] FIG. 12 is a side view of a truck that is outfitted to be a
heated enclosure.
[0020] FIG. 13 is a back view of the truck of FIG. 12 illustrating
a heating film, protective layer and insulating layer that are
utilized to convert the truck to a heated enclosure.
[0021] FIG. 14 is an exploded view of layers, which may comprise a
portion of an enclosure.
[0022] FIG. 15 is an exposed view of layers, which may comprise a
portion of another embodiment of an enclosure.
[0023] FIG. 16 is a top view of a heating element that uses
resistive wires.
[0024] FIG. 17 is a graph of the response of a bi-metallic thermal
switch.
[0025] FIG. 18 is a block diagram illustrating the structure and
layout of an embodiment of a control system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 1 is a perspective view of an embodiment of a suitcase
enclosure 100 that can be heated to kill pests 112. Heat-treatable
materials, such as shirts, clothing and other items, can be placed
in the main enclosure 104 of the suitcase enclosure 100 for heat
treatment. Certain pests such as bedbugs may hide in clothing and
other items that are transported by suitcases, or on the external
surfaces of the suitcase. To ensure that the transported items,
such as the heat treatable material 110, do not contain pests such
as bedbugs, the heat treatable material 110 is placed within the
suitcase enclosure 100, which heats the heat treatable material 110
to a temperature that kills the pests. The suitcase enclosure 100
includes a main enclosure 104 and a hinged lid 102 that attaches to
the main enclosure 104 using matably latchable parts 106. The
surfaces of the main enclosure 104 and hinged lid 102 include
heating layer 132 that heat the main enclosure 104 to specified
temperature for a sufficient amount of time to kill the pests.
Surface temperature sensor 120 senses the interior surface
temperature of various surfaces within the suitcase enclosure 100,
including the hinged lid 102. A power cord 122 is connected to the
user interface 114 of the suitcase enclosure 100. Power cord 122 is
plugged into an external power source 124 to obtain power to heat
the suitcase enclosure 100 using the heating layer 132. User
interface 114 is used to control the process of heating the
suitcase enclosure 100. A central temperature sensor 118 senses the
temperature in a central portion of the main enclosure 104. The
central temperature sensor 118 can be placed in any desired
location in the main enclosure 104 to detect temperatures within
the suitcase enclosure 100 to ensure that a sufficiently high
temperature is reached for a sufficiently long time to kill the
pests.
[0027] For example, a user may wish to obtain central target
temperatures ranging from approximately 120.degree. F. to
approximately 150.degree. F. for a period of between 30 minutes and
an hour for the purpose of killing pests, such as bedbugs,
contained within the main enclosure 104. To fulfill this
requirement, simple programming controls can be entered by a user
through the user interface 114. The user interface 114 can be used
to program the central target temperature, wall temperatures,
and/or length of time that heat is applied to the suitcase
enclosure 100. It has been empirically determined that maintaining
a temperature of 120 degrees for a period of one minute will kill
bedbugs. However, extended heat treatment, such as disclosed above,
will ensure that the required elevated temperatures are reached in
all portions of the main enclosure 104 for a sufficient time to
kill pests, such as bedbugs and their eggs. Further, when elevated
temperatures are maintained for a period of time in the suitcase
enclosure 100, the heat permeates the structure of the suitcase
enclosure 100, so that the external surfaces of the suitcase
enclosure 100 also become heated. As the external surfaces of the
suitcase enclosure 100 become heated, the pests, including bedbugs,
will egress from the outer surfaces and external features 126 of
the suitcase enclosure 100 and eggs will be destroyed. In this
manner, the pests 112 are exterminated in the inside and egress, or
are exterminated on outer surfaces of the suitcase enclosure 100.
This process can be performed at a remote location from the user's
home to prevent transportation of the pests to the user's home. For
example, the user may activate the user interface 114 in a hotel
room prior to leaving the hotel room, or in an airport or other
remote location. Alternatively, the process can be performed at the
user's home employing methods to contain the pests 112 to prevent
egress into the home. The pests 112 are either killed or egress
from the outside surfaces of the suitcase enclosure 100 prior to
being transported back to the user's home. In that regard, the user
interface 114 can be used to change both the duration time of the
heating cycle and/or the temperature of the heating cycle within
the suitcase enclosure 100. During the heating cycle that is set by
the user interface 114, the hinged lid 102 is preferably secured to
the main enclosure 104 using the matably latchable parts 106. In
this manner, the heating layer 132 can concentrate the heat within
the interior portion of the main enclosure 104. User interface 114
can provide a display that presents the interior temperature sensed
by central temperature sensor 18, surface temperatures sensed by
surface temperature sensor 120, and elapsed time. After the heat
cycle has been performed, additional heat cycles can be employed if
desired by the user. Further, heat treatable material 110 can be
then removed from the suitcase enclosure 100, and additional heat
treatable material 110 can be placed in the suitcase enclosure 100
for treatment.
[0028] FIGS. 2-7 comprise various views of the suitcase enclosure
100. FIG. 2 is a top end view of the suitcase enclosure 100. As
shown in FIG. 2, the matably latchable parts 106 secure the hinged
lid 102 to the main enclosure 104. The matably latchable parts 106
may comprise a zipper, latches, snaps, seal or other means of
mating the hinged lid 102 to main enclosure 104. FIGS. 3, 4, 5, 6
and 7 illustrate the different sides of the suitcase enclosure 100
and show external features 126, such as seams, corner guards, or
wheels. In that regard, the suitcase enclosure 100 may take any
desired form or shape. In addition, the suitcase enclosure 100 may
comprise other types of portable enclosures for treating heat
treatable material 110. In addition, suitcase enclosure 100 may be
large enough to treat not only clothing, shoes and other types of
personal items, but also items such as sheets and blankets, jackets
and coats and other larger items. Clearly, one of the advantages of
the suitcase enclosure 100 is that it is a portable, self-contained
unit that is capable of connecting to a power source, such as a
wall plug. In addition, the suitcase enclosure can be implemented
to attach to other power sources, such as 12 or 24 volt outputs,
such as through a cigarette lighter disposed on a vehicle, such as
a car, truck, boat, etc.
[0029] FIG. 8 is a cross-sectional view of the suitcase enclosure
100 illustrating the various parts and construction of the suitcase
enclosure 100. As illustrated in FIG. 8, the suitcase enclosure 100
includes a hinged lid 102 and main enclosure 104 that form an
internal space 108. A movable central temperature sensor 118 is
connected to a conductive tether 116, which allows the central
temperature sensor 118 to be placed in any desired location within
the internal space 108 of the suitcase enclosure 100. The main
enclosure 104, as well as the hinged lid 102, include a plurality
of layers 140. Exterior surface layer 134 can be made from a
canvas, plastic, leather, or other materials commonly used in the
manufacturing of luggage. An insulating layer 136 is disposed on
the external layer 134. The insulating layer 136 assists in
insulating the internal space 108 from the exterior surface layer
134 and traps the majority of the heat generated within the
internal space 108 while transferring some amount of heat to the
exterior surface layer 134. A heating layer 132 is disposed over
the insulating layer 136. The heating layer 132 may comprise a
heating film, such as heating film available from Korean Heating
Company, Ltd., 1513-5 Dadae-Dong, Saha-Gu, Busan, South Korea;
telephone number 82-51-264-2626; fax number 82-51-264-1626, Daewoo
Electric Heating Company, Ltd., 188-1, Jangsa-Dong, Jongro-Gu,
Seoul, South Korea; telephone number 82-2-2268-2011; fax number
82-2-6442-1963, or SEGGI CENTURY, Rm 908, Mugwang office building
1141-1, Jung-dong, Wonmi-gu, Bucheon-SI, Gyeonggi-do, South Korea;
telephone number 82-32-3286699; fax number 82-32-3286464. As
illustrated in FIG. 8, the heating layer 132 is disposed on all
sides of the suitcase enclosure 100. The application of heat from
multiple surfaces allows the entire contents of the enclosure to be
treated, to ensure that the pests 112 are killed and that pests on
the outside of the suitcase enclosure 100 are either killed or
egress from the surfaces of the suitcase enclosure 100.
[0030] A heating film can be produced by screen printing an
electrically resistive ink onto a substrate so that a plurality of
narrow circuit lines are produced in the substrate. The resistive
ink then generates radiated heat in the IR spectrum that is capable
of penetrating much of the contents of enclosure 100. In this
manner, standard convection of air through, the internal space 108
of suitcase enclosure 100 is not relied upon for distribution of
heat. Infrared radiation absorbed by the heat treatable materials
110 in conjunction with thermal conduction ensures that the
necessary temperatures are achieved throughout the internal space
108 in the main enclosure 104. Of course, the materials used as
resistive materials in the resistive ink of the heating film can be
varied to create longer wave IR signals that are even more
efficient at penetrating the heat treatable material 110.
[0031] Alternatively, heating layer 132 can be constructed from a
resistive wire heating element, which is more fully disclosed with
respect to FIG. 16. A thermal conductive layer 138 is placed over
the heating layer to increase the heat uniformity to the internal
space 108. A liner 139 may be placed over the thermal conductive
layer 138. The liner 139 is capable of transmitting heat generated
from the thermal conductive layer 138 to the internal space
108.
[0032] The heating film has additional advantages for application
in the suitcase enclosure 100. The heating film is mass-produced
using inexpensive screen printing techniques. A very uniform
heating profile can be generated using heating films as a result of
easily instituted process controls that easily maintain consistent
mixtures and uniform distribution of the resistive materials
throughout the screen applied inks. Alternatively, non-uniform
heating profiles may be designed into the screen printing process
to address hot spots or cold spots in the application. Further, the
heating films are extremely thin, i.e., on the order of 0.25 mm. As
such, the heating films are lightweight and moderately pliable to
shapes that will fit the suitcase enclosure 100. The operating
temperatures of the film are in the range of 70 to 80.degree. C.,
which is ideally suited for killing pests 112. The extremely light
weight of the heat films adds virtually no detectable weight to the
overall suitcase enclosure 100 and other portable devices in which
the heating film can be used. Of course, the weight of a suitcase
and other portable devices is an important factor to the marketing
and sale of these devices. The addition of a very small and
virtually undetectable amount of weight to a suitcase that has the
ability to kill pests, as well as providing these solutions at only
a moderately higher price, is an advantage in the sale and
marketing of the suitcase enclosure 100. The implementation of heat
films in commercial products, in addition, does not face
substantial impediments. Heat films are UL, CE and CSA approved.
The construction of the films allows for easy modification for
various power densities and voltages. Application techniques to the
substrate allow for minimum gap between the heating elements in a
simple and cost effective manner. Current films are available in
30, 50, 60, 80 and 100 cm widths that are easily modified to
provide designs that fit exactly into any desired enclosure.
[0033] Alternatively, a heating film can be directly applied to a
substrate layer that forms a portion of the main enclosure 104 and
hinged lid 102 of the suitcase enclosure 100. As indicated above,
the heating film may be applied to a substrate layer, which may
simply comprise the exterior surface layer 134, using lithographic
techniques, silk screening techniques or other techniques in which
the resistive ink is applied directly to the substrate. In
addition, a protective layer that has a reasonably high thermal
conductivity can be applied directly over the applied resistive ink
to provide a protective layer for the resistive ink. Spray-on
plastics and other materials can be used to protect the resistive
ink. For example, polyurethanes and polyureas can be used, as well
as other protective films. Any thin film polymer, including
polyethylene, polypropylene and similar polymers, can provide
sufficient protection of the conductive/resistive ink layer. The
polymer can have a thickness that is sufficient to conduct the
infrared radiation, while still providing protection to the
conductive/resistive ink. The polymer layer can be thin enough to
allow conduction of the heat through the polymer layer and not
providing a significant insulation to the heating element.
[0034] FIG. 8 also illustrates the suitcase controller 142 and the
user interface 114. The suitcase controller 142 may comprise a
simple and inexpensive microprocessor controller that is easily
programmable to operate with the user interface 114. The user
interface may comprise an inexpensive touch screen display, or a
combination of LEDs and buttons, that can be utilized for input of
user data. Both the user interface 114 and the suitcase controller
142 are inexpensive and can be readily programmed to perform the
required control functions.
[0035] FIG. 9 is a perspective view of one embodiment of a user
interface 114. As shown in FIG. 9, the user interface is disposed
in a location beneath the retractable handle 143, which assists in
protecting the user interface 114 from damage or accidental
activation. In the embodiment illustrated in FIG. 9, an activation
element 144, in the form of a button, is utilized for the input of
user data or to initiate a heat cycle. Bulkhead connector 146
provides a connector for connecting the external power source.
Status indicator 148 may comprise any desired type of display for
displaying operational data of the suitcase enclosure 100.
[0036] FIG. 10 is a flow diagram illustrating the operational steps
of suitcase controller 142, as well as the workflow steps of a user
of the suitcase enclosure 100. At step 150, the user closes a bag
and inserts a power cord into the jack that is disposed in the
bulkhead connector 146. At step 152, the suitcase controller 142
checks for system faults and determines whether the source of power
is either 120 volts or 240 volts AC. Additionally, the controller
can also test for 12 volt DC and 24 volt DC power inputs. If it is
determined that faults exist, or there are other operational
problems with the system, the user interface can provide an
indication of the fault. In one example, the user interface may
flash a red LED and maintain the heating element in an off
condition. If it is determined at step 152 that no faults or system
problems exist, the heating elements are turned on and the heating
process begins. An indication that the bag is operating and other
data may also be displayed. In one example, a yellow LED may be
illuminated. At step 158, the wall temperatures of the suitcase
enclosure 100 are raised to a predetermined temperature level at a
safe ramp rate. In the embodiment illustrated in FIG. 10, the wall
temperatures are raised to a temperature of 150.degree. F. At step
160, the suitcase controller 142 initiates a timer for a
pre-selected time period for operation of the heating element.
Alternatively, a user may specify a time period and may specify a
repeating interval for heating the suitcase enclosure 100. In
addition, the suitcase controller 142 monitors the temperatures
from the central temperature sensor 118 and the surface temperature
sensor 120. The suitcase controller 142 may turn the heating
element on and off to maintain the desired temperature, for
example, 150.degree. F., during the heating interval. Once the
heating interval is completed, the user interface 114 may indicate
a successful heating internal process to the user. In one
embodiment, a green light may be illuminated by the suitcase
controller 142 in the user interface 114. If the heating interval
is interrupted because a problem exists, such as the central
temperature sensor 118 or the surface temperature sensor 120
detects overheating, the heating element is switched off and the
failure of the heating interval is indicated on the user interface
114. In the example of FIG. 10, a red LED is illuminated.
[0037] FIG. 11 illustrates another embodiment of an enclosure,
which comprises a box 200. The box 200 comprises an exterior carton
218 that has a bulkhead receptacle 220 that is adapted to receive
the power cord 212. The power cord 212 can plug into the power
source 214 to provide power to the box 200. The insulating floor
208 and insulating walls 206 are placed in the internal space 216
of the exterior carton 218. A heating film 202, that is formed to
fit inside the insulating walls 206, is placed on the interior
surface of insulating walls 206. An insulating lid 204 is then
placed on top of the box-shaped heating film 202. Closing flaps 210
can be closed upon activation of the power cord 212. The box 200 of
FIG. 11 is a simpler design and less expensive design than the
suitcase enclosure 100 of FIG. 1. Power cord 212 can simply be
plugged into a power source 214 for a set period of time, which
eliminates the need for a controller. Further, a user interface is
not required with the box 200, but rather, the user simply keeps
the power cord 212 plugged into the power source 214 and bulkhead
receptacle 220 for a given period of time, such as 60 to 480
minutes. Bi-metallic switches can be used to control the current
and temperature in the manner described with respect to FIG. 16.
Box 200 provides a simple and cost effective manner of creating an
enclosure to kill pests and can be easily constructed in an
inexpensive manner. Again, the heating film 202 is disposed on
multiple sides of the box 200 to ensure that heat is being applied
from multiple surfaces, to ensure that the pests are killed or
egress from the outer surfaces of the box 200.
[0038] FIG. 12 is a side view of a truck/trailer 300 that includes
an enclosure 310 that forms part of the truck/trailer 300. A user
interface 308 is provided on an outside surface of the enclosure
310.
[0039] FIG. 13 is a rear view of the truck/trailer 300 showing the
door 312 in an open position. A rear view in FIG. 13 is a partial
cutaway view showing portions of the protective layer 306 that
covers the heating film 302. The heating film 302 is placed on the
interior walls of the truck/trailer 300 and on a floor portion of
the truck/trailer 300. An insulating layer 304 is shown in a
cut-away portion of the sidewalls of the truck/trailer 300. The
insulating layer 304 may comprise any desired type of insulating
material that can be placed in the walls of the truck/trailer 300.
Insulating layer 304 may be attached directly to the inside surface
of the walls of the truck/trailer 300 or may constitute foam
insulation that is injected into the walls of the truck/trailer
300. The heating film 302 can be formed in large sheets that are
constructed to fit on the walls and the truck bed of truck/trailer
300. Each of the sections of the heating film 302 can then be wired
to the user interface 308. The protective layer 306 may comprise a
spray-on protective coating, such as used in truck bed liners. The
protective layer 306 may be a homogeneous protective surface that
is applied directly to the heating film 302 to provide a durable
working surface to transport items for heat treatment. Various
polymers can be used for the protective layer that can be sprayed
on or directly applied to the heating film 302. These polymers may
comprise polyurethanes, polyureas, pure polyureas and similar
materials that have durable characteristics between -50.degree. F.
and 200.degree. F. Coatings may include Rhino Extreme 21-55
available from Rhino Linings Corp., 9151 Rehco Road, San Diego,
Calif. 92121. Other protective coatings can be used, such as Line-X
Excess-350 available from Line-X Protective Coatings, 6 Hutton
Center Drive, Suite 500, Santa Ana, Calif. 92707. Both of these
protective coatings comprise spray-on elastomers that are easily
applied over the heating film 302. Although FIGS. 12 and 13
illustrate a truck/trailer 300 having an enclosure 310, the
identical process can also be used with stand-alone trailers.
[0040] Since bedbugs can be easily spread in furniture and other
household and office items, the use of a truck or a trailer to kill
pests, such as bedbugs, is extremely beneficial. For example, if
bedbugs have infested furniture, including beds, couches, chairs,
etc. in a home, the furniture can be removed and placed in the
truck or trailer and subjected to one or more heat cycles within
the trailer to kill the bedbugs. The furniture can then be placed
back in the house with the assurance that the bedbugs have been
exterminated. Further, if a user is moving from one location to
another, the truck/trailer 300, or a similarly constructed trailer,
can be used to transport furniture that may be infected with
bedbugs. One or more heating cycles may be used to ensure that
bedbugs are exterminated from the furniture and other household
items during the transportation of the items to a new location.
Further, new furniture that is being transported to a purchaser can
also be treated to ensure that there has no been infestation of
bedbugs or other pests. As further illustrated in FIG. 13, the
heating film 302 is applied to multiple surfaces, including the
floor surface of the truck/trailer 300, to ensure that the contents
of the truck/trailer 300 are fully exposed to heat applied by the
heating film 302. This ensures that pests are killed on the
contents of the truck/trailer 300.
[0041] FIG. 14 is an exploded view of a portion of an enclosure
with a surface heater 401 that utilizes a heating film 410. The
enclosure can comprise any desired type of surface heater 401 that
has a plurality of layers 400. As illustrated in FIG. 14, the
heating film 410 has a plurality of carbon ink channels 416 that
pass the electrical current 438 from bus bar 414. The heat
conductive layer 412 is disposed over the heating film 410 to
protect the heating film 410 from damage and increase the heat
uniformity to the interior surface 442. The heat conductive layer
412 can comprise any desired material that has at least a moderate
degree of thermal conductivity. As such, internal heat transfer 418
to the interior portion of the enclosure 402 occurs preferentially
over the external heat transfer 420 to exterior space of the
enclosure 404 of the enclosure, since insulation layer 408 is
disposed between the heating film 410 and the exterior surface
layer 406. Exterior surface layer 406 can be used to support the
insulation layer 408. The exterior surface layer 406 can be
selected from a numerous and wide variety of materials, such as
those conventionally used in the external wall construction of
luggage, including soft and hard luggage, such as metal, fabric,
plastic, fiberglass or similar materials, to provide the exterior
surface layer 406 with the proper rigidity necessary to create the
enclosure. In addition, the exterior surface layer 406 may comprise
materials that are conventionally used for the exterior wall
construction of various containers as illustrated in FIG. 11, such
as paperboard, cardboard, corrugated plastic, or similar materials
commonly used by the packaging industry. The exterior surface layer
406 may be selected depending upon the intended use of the
enclosure and the ability to properly enclose the insulation layer
408 and the heating film 410. The insulation layer 408 may be
disposed adjacent to, and mounted on, the exterior surface layer
406. The insulation layer 408 may be selected from a numerous and
wide variety of materials to provide a heat transfer barrier
between the interior portion of the enclosure 402 and the exterior
surface layer 406 surrounding enclosure. The internal heat transfer
418 to the internal portion of the enclosure 402, versus the
external heat transfer 420 to the external space of the enclosure
404, is determined by the insulated value of the insulation layer
408, the thermal conductivity of the heat conductive layer 412, as
well as the temperature difference between the interior portion of
the enclosure 402 and the exterior space of the enclosure 404. It
is desirable to have external heat transfer 420 to the exterior
surface layer 406 to cause pests, such as bedbugs, to egress from
the exterior surface layer 406. At the same time, it is desirable
to have an insulation layer 408 that is sufficient to cause the
internal heat transfer 418 to the interior portion of the enclosure
402, so that a sufficient amount of heat is generated in the
interior portion of the enclosure 402 to kill pests, such as
bedbugs. Accordingly, the insulation layer 408 may comprise a
plastic sheet material that is applied to the exterior surface
layer 406, such as foam board, closed or open cell foam, sheet or a
spray foamed material, such as polyurethane foam, corrugated
cardboard, fiber fill, such as bamboo fill, cotton fill, synthetic
fiber fill, such as polyester fill, air filled sheets, or bubble
material or similar materials.
[0042] FIG. 15 is another view of the construction of an enclosure
with a surface heater 401 that utilizes resistive wire heating
elements 422. FIG. 15 discloses a plurality of layers 400 that form
an enclosure. An electrical current 438 is applied to resistive
wire heating elements 422, which generate heat by method of Joule
heating. The resistive wire heating elements are supported by
structural layer 440. An insulation layer 408 is disposed between
the structural layer 440 and the exterior surface 406. The
insulative qualities of the insulation layer 408 control the amount
of internal heat transfer 418 to the interior portion of enclosure
402, versus the amount of external heat transfer 420 to the
exterior space of the enclosure 404. A heat conductive layer 412 is
placed over the resistive wire heating elements 422 to protect the
resistive wire heating elements 422 from damage. Heat conductive
layer 412 may comprise any desired heat conductive layer, including
plastic materials and other suitable material. The resistive wire
heating elements 422 can be made from resistive carbon fiber wire,
electrically resistive ribbons, or other similar materials that are
capable of generating heat in response to the flow of electrical
current 438. Electrically resistant wires and ribbons can be made
from nickel, iron, nickel-chrome alloys, nickel-iron alloys, and
similar materials. Wires and ribbons suitable for use with the
invention include Balco alloy, Evanoham, Alloy R, Karma Mid-Ohm and
similar products. Pelican Wire Co Inc, 3650 Shaw Boulevard, Naples,
Fla. 34117-8408, telephone 1 (239) 597-8555; Kanthal 1 Commerce
Blvd, Palm Coast, Fla. 32164; Telephone: +1 (386) 445 20 00; Fax:
+1 (386) 446 22 44
[0043] FIG. 16 is an illustration of a surface heater that uses
resistive wire heating elements 422. FIG. 16 is one embodiment
illustrating the manner in which a resistive wire heating layer can
be constructed to fit within conventional containers, enclosures,
luggage, suitcases, garment bags, briefcases, duffle bags,
backpacks, or the like. As shown in FIG. 16, the sidewall section
430 can be disposed along the sidewall of a container, such as a
box. Floor section 426 can be disposed along a lower portion, while
the lid section 428 can be disposed on an upper portion, of a
container. Structural layer 440 may comprise an insulating layer, a
thermal conductive layer, or a combination of the two. As
illustrated in FIG. 16, one single structure, in the form of a
heating shell 444, can be used to surround the interior or exterior
sides of a heating enclosure in one simple and easy to implement
device. The specific geometry of the heating shell 444, illustrated
in FIG. 16, can be modified to produce various three-dimensional
shapes when folded. Box shapes, rectangular shapes, cylindrical
shapes, frusto-conical shapes, pyramid shapes, and other desired
shapes can be formed depending upon the particular
implementation.
[0044] FIG. 16 also illustrates a pair of thermal switch 432
devices that function to control the temperature of the heating
layer illustrated in FIG. 16. The thermal switch 432 may take the
form of a bimetallic switch that controls the flow of current based
upon the output temperature of the heating layer illustrated in
FIG. 16. In this manner, the thermal switch 432 is capable of
controlling the application of current from power cord 434 to the
resistive wire heating elements 422.
[0045] FIG. 17 is a plot of the response of a bimetallic thermal
switch 436 based on temperature over a period of time. As shown in
FIG. 17, the bimetallic thermal switch is capable of maintaining
the heating element at a temperature between approximately
140.degree. F. and 160.degree. F. Installation of the bimetallic
switches in the circuit of the heating element illustrated in FIG.
16 allows the heating element to automatically maintain a
predetermined temperature between approximately 140.degree. F. and
160.degree. F. Bimetallic switches are available from Cantherm,
8415 Mountain Sight Avenue, Montreal (Quebec), H4P 2B8, Canada,
Typical switches that can be used include Part No.
F20A07005ACFA06E, which switches at 70.degree. C. Part No.
C5705025Y is a bimetallic thermal switch that switches at
50.degree. C.
[0046] FIG. 18 is a schematic block diagram of an embodiment of a
control system 500 that is suitable for use with the present
invention. As illustrated in FIG. 18, the control system 500
includes AC power cord 502, control board 526, heater zone 524,
user interface 520, and remote sensors 522, The AC power cord 502
can be connected to a power source to supply power to a bulkhead
connector 504. Bulkhead connector 504 may comprise a male prong
socket for the AC power cord 502. Power from the bulkhead connector
is supplied to an AC to DC converter 506, which converts an AC
signal to a DC voltage. Power sources in some countries operate on
220-240 volts, rather than US and Canada which operate at 120 volts
AC. In that regard, AC line monitor 508 detects the input voltage
and generates a signal that is supplied to the controller 510,
indicating the voltage range to the input signal from the AC to DC
converter 506. Controller 510 receives user inputs from user
interface 520. User inputs may include control signals to activate
the heating system, duration of the heating time, desired
temperatures, and other input information. User interface 520 also
receives data from the controller 510 that is displayed on the user
interface 520 indicating the operation of the control system 500.
Controller 510 includes analog to digital circuits and logic
circuits for carrying out the logical operations of the control
system 500, Driver circuit 512 is controlled by the controller 510
to supply current to the heater load 516. Driver circuit 512 may
use a triac to control the current applied to the heater load 516,
Driver circuit 512 is connected directly to the power supply from
the bulkhead connector 504 to supply power directly to the heater
load 516, which is disposed in the heater zone 524. A fault
detection circuit 514 is connected to the heater load 516 to
determine if there are any faults in the heater load 516. If so, a
signal is transmitted from the fault detection circuit 514 to the
controller 510 to turn off the power supplied by the driver circuit
512. Temperature sensors 518 provide data to the controller 510 for
operation of control system 500, In addition, remote sensors 522
provide additional information that assists the controller 510 in
proper operation of the control system 500. Temperature sensors 518
may comprise surface temperature sensors, such as surface
temperature sensor 120. Remote sensors 522 may comprise a central
temperature sensor, such as central temperature sensor 118,
illustrated in FIG. 1,
[0047] Controller 510, illustrated in FIG. 18, regulates the power
supplied to the heater load 516. In this manner, the temperature
generated by the heater load 516 then can be increased or decreased
in response to the information provided by temperature sensors 518,
and remote sensors 522. Controller 510 can increase the temperature
of the heater load 516 at a predetermined rate to aggressively
approach a surface target temperature. Controller 510, together
with the temperature sensors 518, and remote sensors 522, can be
considered to be a closed proportional-integral derivative circuit.
Using a controlled fixed rate of increase in the power applied to
heater load 516 can reduce the thermal shock to the heat treatable
materials that are disposed within the interior space of the
heating enclosure. A triac used in the driver circuit 512 clips the
sinusoidal waveform of the AC circuit that is applied from the
bulkhead connector 504 to reduce delivered power. For example, to
cut the delivered power by 50 percent on a 60 hertz system, the
triac would clip half of the waveform. Although only a single
heater zone 524 is illustrated, multiple heater zones may be
utilized. In that case, controller 510 can function to reduce
instantaneous power consumption by zero-cross switching and
distributing the AC power across the multiple heating zones. For
example, if a first heating zone requires 25 percent power and a
second heating zone requires 50 percent power, the controller can
synchronize a first triac to conduct for 15 cycles per second. The
controller can also control a second triac to conduct 30 cycles per
second and stop conducting for the next 15 cycles per second. In
this manner, multiple triacs can be used to supply power to
different heating loads.
[0048] Referring to Table 1, a preselected temperature and the
period of time for treatment can vary depending on the pest which
is being caused to egress from within, or from the external surface
of, the enclosure body, or which is being killed within the
enclosure body, or on the external surface of the enclosure body,
in association with the heat treatable material. For the purposes
of this invention the term "pest" encompasses a wide range of
pathogens, molds, or insects (whether as adult, larvae, or
eggs).
TABLE-US-00001 TABLE 1 Temperature Time Pathogen Enteric viruses 60
C. Rapidly Salmonellae 60 C. 20 Hours Shigellae 55 C. 60 Minutes E.
coli 60 C. Rapidly Entamoebahystolytica cysts 50 C. 5 Minutes
Hookworm eggs 50 C. 5 Minutes Roundworm eggs 55 C. 120 Minutes
Molds Wood Fungi (Staining Fungi) 66 C. 75 Minutes Basidiomycotina
50 C. N/A Poria-Wood Eating Fungi 66 C. 75 Minutes
(MeruliporiaIncrassata) Fomes (FomitopsisRosea) 66 C. 75 Minutes
StachybotrysChartarum 60 C. 30 Minutes AspergillusAlutaceus 62 C.
20 Minutes AspergillusAcandidus 62 C. N/A AspergillusUstus 62 C. 25
Minutes AspergillusWenti 63 C. 25 Minutes Aspergillus Niger 63 C.
25 Minutes Alternaria Alternata 63 C. 25 Minutes Insects Bed Bug
Adults & Nymphs 45 C. 15 Minutes Bed Bug Eggs 45 C. 60 Minutes
German Cockroach-Adult Male 49 C. 27 Minutes 54 C. 7 Minutes Flour
Beetle 49 C. 16 Minutes 54 C. 4 Minutes Drywood Termite Nymphs 49
C. 30 Minutes 54 C. 6 Minutes Agentine Ant (Adults) 49 C. 4 Minutes
54 C. 1 Minute
[0049] Hence, the various embodiments disclosed herein provide
various ways of killing bedbugs, or other pests, in containers and
causing such pests to egress from surfaces of the container.
Various types of containers are disclosed, including suitcases,
standard boxes, trailers, trucks and similar devices. The various
types of containers and enclosures can be retrofit with a heating
film or a resistive wire heating element to create an enclosure
that is capable of killing pests. These enclosures can also be
retrofit with various controllers, including a user interface, as
well as simple controllers, such as a bimetallic switch. This
system uses simple surface heaters on multiple sides of the
enclosure, such as heating film and resistive wire heating layers.
Inexpensive control systems are used, including bimetallic
switches, closed loop controllers, and other systems. Heating films
are ideal for use on the various enclosures since they are low
cost, extremely thin, lightweight and pliable, and can produce
optimal temperature ranges for killing pests. Further, infrared
wavelengths, on the order of to 1000 nanometers, that are generated
by the heating film, allow the heat to penetrate materials within
the enclosure, rather than relying upon convective air currents.
Heating films are safe to use and can be either custom designed for
application directly to an enclosure or provided in a pre-made film
having various widths.
[0050] The foregoing description of the invention has been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to the precise
form disclosed, and other modifications and variations may be
possible in light of the above teachings. The embodiment was chosen
and described in order to best explain the principles of the
invention and its practical application to thereby enable others
skilled in the art to best utilize the invention in various
embodiments and various modifications as are suited to the
particular use contemplated. It is intended that the appended
claims be construed to include other alternative embodiments of the
invention except insofar as limited by the prior art.
* * * * *