U.S. patent application number 13/357633 was filed with the patent office on 2012-05-17 for transportable decontamination unit and decontamination process.
Invention is credited to Michael A. Bacik, Peter J. Buczynski, Michael A. Centanni, Aaron L. Hill, Iain F. McVey, Timothy W. Meilander, Richard A. Weiss, Paul W. Wiget.
Application Number | 20120121462 13/357633 |
Document ID | / |
Family ID | 39494312 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120121462 |
Kind Code |
A1 |
Bacik; Michael A. ; et
al. |
May 17, 2012 |
TRANSPORTABLE DECONTAMINATION UNIT AND DECONTAMINATION PROCESS
Abstract
The disclosed invention relates to a portable decontamination
unit. The invention also relates to a decontamination process. The
decontamination unit may be ruggedized for use in hostile
environments such as those that may be anticipated for military
applications.
Inventors: |
Bacik; Michael A.;
(Fairview, PA) ; Hill; Aaron L.; (Erie, PA)
; Buczynski; Peter J.; (Girard, PA) ; Weiss;
Richard A.; (Willoughby, OH) ; Meilander; Timothy
W.; (Broadview Heights, OH) ; Wiget; Paul W.;
(Mentor, OH) ; McVey; Iain F.; (Lakewood, OH)
; Centanni; Michael A.; (Parma, OH) |
Family ID: |
39494312 |
Appl. No.: |
13/357633 |
Filed: |
January 25, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12033904 |
Feb 20, 2008 |
8128888 |
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13357633 |
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60893134 |
Mar 6, 2007 |
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60962876 |
Aug 1, 2007 |
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Current U.S.
Class: |
422/37 ; 422/28;
588/1; 588/299; 588/401 |
Current CPC
Class: |
A61L 2202/26 20130101;
A61L 2/208 20130101; A61L 2202/122 20130101 |
Class at
Publication: |
422/37 ; 422/28;
588/299; 588/401; 588/1 |
International
Class: |
A61L 2/20 20060101
A61L002/20; A62D 101/02 20070101 A62D101/02; G21F 9/00 20060101
G21F009/00; A62D 3/00 20070101 A62D003/00 |
Claims
1-13. (canceled)
14. A process for operating a self-contained transportable
decontamination unit, comprising: a housing containing a
decontamination chamber and a decontaminant processing section; and
a military master pallet on which the housing is positioned; the
decontamination chamber comprising a first entrance with a first
door, the first entrance being adapted for placing articles to be
decontaminated in the decontamination chamber, and an opposite
second entrance with a second door, the second entrance being
adapted for removing decontaminated articles from the
decontamination chamber, the decontamination chamber including at
least one gas inlet for admitting a decontaminant air stream into
the decontamination chamber from the decontaminant processing
section and at least one gas outlet for permitting a gaseous air
stream to flow out of the decontamination chamber into the
decontaminant processing section; the decontaminant processing
section comprising a power generator and a decontaminant generator,
the power generator being adapted for providing electrical
operating power for the decontaminant generator, the decontaminant
generator being adapted for destroying residual amounts of
decontaminant in the gaseous air stream, dehumidifying the gaseous
air stream, and adding decontaminant to the gaseous air stream to
form the decontaminant air stream; wherein the housing and the
decontamination chamber are (1) hardened to ensure that five
exposures to chemical, biological, radiological or nuclear
contaminants, decontaminants and decontaminating procedures over a
thirty-day period do not cause the housing or decontamination
chamber to require corrective maintenance during that thirty-day
period; (2) constructed to withstand temperatures ranging from
about -32.degree. C. to about 49.degree. C.; (3) constructed to
withstand relative humidities ranging from about 5% to about 100%;
and (4) constructed to operate when exposed to conventional hazards
of solar radiation, rain, fungus, salt fog, sand, dust, vibration
and shock; and wherein the power generator and decontaminant
generator are ruggedized, the process comprising: opening the first
door; placing one or more contaminated articles in the
decontamination chamber; closing the first door; operating the
power generator to provide power to operate the decontaminant
generator; flowing the decontaminant air stream from the
decontaminant processing section into the decontamination chamber;
contacting the contaminated articles in the decontamination chamber
with the decontaminant air stream to decontaminate the contaminated
articles; flowing the gaseous air stream from the decontamination
chamber back to decontaminant processing section; opening the
second door; and removing the decontaminated articles from the
decontamination chamber.
15. The process of claim 14 wherein the decontaminant comprises a
peracid, peroxide, hypochlorite, ozone, or a mixture of two or more
thereof.
16. The process of claim 14 wherein the decontaminant comprises
hydrogen peroxide.
17. The process of claim 15 wherein the decontaminant further
comprises a solvent.
18. The process of claim 15 wherein the decontaminant further
comprises an alkaline gas.
19. The process of claim 14 wherein the decontaminant comprises
vaporous hydrogen peroxide and ammonia.
20. The process of claim 14 wherein the contaminated articles
comprise one or more of military weapons, clothing, body armor,
computers, test equipment, optical devices, electronic devices
and/or communications equipment.
21. The process of claim 14 wherein the contaminated articles are
contaminated with one or more chemical, biological, radiological
and/or nuclear warfare agents.
22. The process of claim 14 wherein the contaminated articles are
contaminated with one or more bacterial spores, vegetative
bacteria, viruses, molds and/or fungi.
23. The process of claim 14 wherein the contaminated articles are
contaminated with one or more pathogenic chemical agents.
24. The process of claim 14 wherein the step of contacting the
contaminated articles with the decontaminant air stream comprises a
dry process characterized by the absence of condensate formation on
the surface of the contaminated articles being decontaminated.
25. The process of claim 14 wherein the step of contacting the
contaminated articles with the decontaminant air stream comprises a
wet process characterized by the formation of condensate on the
surface of the contaminated articles being decontaminated.
26. The process of claim 25 wherein the condensate comprises
hydrogen peroxide.
Description
[0001] This application claims benefit under 35 U.S.C. .sctn.119(e)
to U.S. Provisional Application Ser. No. 60/893,134, filed Mar. 6,
2007, and U.S. Provisional Application Ser. No. 60/962,876, filed
Aug. 1, 2007. These applications are incorporated herein by
reference in their entireties.
TECHNICAL FIELD
[0002] This invention relates to a transportable decontamination
unit and to a decontamination process.
BACKGROUND
[0003] Decontaminant generating systems, such as those used to
generate vaporous hydrogen peroxide (VHP), have been used to
decontaminate large enclosures such as rooms and buildings (e.g.,
hotel rooms, hospital wards, scientific laboratories, etc.) from
contaminants such as bacteria, molds, fungi, yeasts, and the
like.
SUMMARY
[0004] It would be advantageous for the military to use these
decontaminant systems in the field in defense against chemical and
biological weapons. However, a problem with these decontamination
systems is that they are not readily transportable. This invention
provides a solution to this problem. This invention relates to a
decontamination unit that is self-contained, readily transportable
and has a relatively large-scale decontamination chamber. This
invention relates to a transportable decontamination unit,
comprising: a housing containing a decontamination chamber and a
decontaminant processing section; the decontamination chamber
comprising a first entrance with a first door, the first entrance
being adapted for placing articles to be decontaminated in the
decontamination chamber, and an opposite second entrance with a
second door, the second entrance being adapted for removing
decontaminated articles from the decontamination chamber, the
decontamination chamber including at least one gas inlet for
admitting a decontaminant air stream into the decontamination
chamber and at least one gas outlet for permitting a gaseous air
stream to flow out of the decontamination chamber; the
decontaminant processing section comprising a power generator and a
decontaminant generator, the power generator being adapted for
providing power for the decontaminant generator, the decontaminant
generator being adapted for destroying residual amounts of
decontaminant in the gaseous air stream, dehumidifying the gaseous
air stream, and adding decontaminant to the gaseous air stream to
form the decontaminant air stream.
[0005] This invention relates to a process for operating the
foregoing decontamination unit, comprising: opening the first door;
placing one or more contaminated articles in the decontamination
chamber; closing the first door; operating the power generator to
provide power to operate the decontaminant generator; flowing the
decontaminant air stream from the decontaminant processing section
into the decontamination chamber; contacting the contaminated
articles in the decontamination chamber with the decontaminant air
stream to decontaminate the contaminated articles; flowing the
gaseous air stream from the decontamination chamber back to
decontaminant processing section; opening the second door; and
removing the decontaminated articles from the decontamination
chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] In the annexed drawings all parts and features have like
references. A number of the annexed drawings are schematic
illustrations which are not necessarily proportioned accurately or
drawn to scale.
[0007] FIG. 1 is a schematic illustration of a decontamination unit
within the scope of the present invention. The decontamination unit
includes a decontaminant processing section and a decontamination
chamber.
[0008] FIG. 2 is a schematic illustration of the decontamination
unit illustrated in FIG. 1 with sides of the unit removed to show
the interior of the decontaminant processing section. The
decontaminant processing section includes a power generator,
decontaminant generator, and control unit. Part of the interior of
the decontamination chamber as well as a loading cart for use in
the decontamination chamber are also shown. Portable tracks for
rolling the loading cart into one side of the decontamination
chamber and removing the loading cart from the other side of the
decontamination chamber are shown.
[0009] FIG. 3 is a view of the decontamination unit illustrated in
FIG. 2 taken from the opposite side shown in FIG. 2.
[0010] FIG. 4 is a view of the decontamination unit illustrated in
FIG. 3 with the loading cart removed from the decontamination
chamber and positioned on one of the portable tracks located
outside the decontamination chamber.
[0011] FIG. 5 is a schematic illustration showing a locking
mechanism for connecting the portable tracks illustrated in FIGS.
2-4 to interior tracks in the decontamination chamber.
[0012] FIG. 6 is a flow sheet showing the operation of the
decontaminant generator illustrated in FIG. 2.
DETAILED DESCRIPTION
[0013] All ranges and ratio limits disclosed in the specification
and claims may be combined in any manner. It is to be understood
that unless specifically stated otherwise, references to "a", "an",
and/or "the" may include one or more than one, and that reference
to an item in the singular may also include the item in the plural.
All combinations specified in the claims may be combined in any
manner.
[0014] The term "ruggedized," and like terms such as
"ruggedization," are used herein to refer to apparatus that is: (1)
hardened to ensure that five exposures to chemical, biological,
radiological or nuclear (CBRN) contaminants, decontaminants and
decontaminating procedures over a thirty-day period do not cause
the apparatus to require corrective maintenance during that
thirty-day period; (2) capable of being used at temperatures
ranging from about -32.degree. C. to about 49.degree. C.; (3)
capable of being used in relative humidities ranging from about 5%
to about 100%; and/or (4) capable of operating when exposed to
conventional hazards of solar radiation, rain, fungus, salt fog,
sand, dust, vibration and/or shock in accordance with Military
Standard 810 (MIL-STD-810).
[0015] The term "line" when referring to the drawings may refer to
any conduit for conveying a fluid. The conduit may be in any
desired form, for example, one or more pipes, tubings, channels,
and the like. These may be made of materials sufficient to provide
the required properties of strength, flexibility, and resistance to
the fluids being conveyed. The lines may be ruggedized to permit
use in hostile environments such as those that may be encountered
in military applications.
[0016] The term "fluid" may refer to a liquid, gas, or mixture
thereof.
[0017] The inventive decontamination unit, in its illustrated
embodiment, will be described with reference to FIGS. 1-6.
Referring to FIGS. 1-6, decontamination unit 100 comprises housing
110 which contains decontaminant processing section 200 and
decontamination chamber 400. The housing 110 includes removable
side panels 114, 116 and 118, side panel 119, and vents 120, 122
and 124. The housing 110 includes top panel 126. The
decontamination unit 100 is positioned on pallet 128. Part of the
housing 110 forms the exterior walls of the decontamination chamber
400.
[0018] The decontamination unit 100 may be of sufficient size and
weight to provide the decontamination chamber 400 with the desired
internal volume to provide for decontamination on a large scale and
yet allow the decontamination unit 100 to be readily transportable.
The decontamination chamber 400 may have an internal volume in the
range from about 0.5 to about 10 cubic meters, and in one
embodiment from about 2.5 to about 7.5 cubic meters, and in one
embodiment from about 4 to about 7 cubic meters, and in one
embodiment from about 6 to about 7 cubic meters, and in one
embodiment about 6.8 cubic meters. The decontamination unit 100 may
have a height (as measured from the base support 128 to the top
panel 126) in the range from about 0.5 to about 2.5 meters, and in
one embodiment in the range from about 1 to about 2.5 meters, and
in one embodiment in the range from about 1.5 to about 2.5 meters,
and in one embodiment in the range from about 2 to about 2.5
meters, and in one embodiment in the range from about 2.3 to about
2.5 meters, and in one embodiment about 2.4 meters. The
decontamination unit 100 may have a width (as measured from side
130 to side 132) in the range from about 1 to about 2.5 meters, and
in one embodiment in the range from about 1.5 to about 2.5 meters,
and in one embodiment in the range from about 2 to about 2.5
meters, and in one embodiment about 2.2 meters. The decontamination
unit 100 may have a length (as measured from the first entrance 420
to the second entrance 430) in the range from about 1.2 to about
2.8 meters, and in one embodiment in the range from about 2 to
about 2.8 meters, and in one embodiment in the range from about 2.5
to about 2.8 meters, and in one embodiment about 2.7 meters. The
overall weight of the decontamination unit 100 may be in the range
from about 500 to about 10,000 pounds (227 to 4536 Kg), and in one
embodiment in the range from about 500 to about 7,500 pounds (227
to 3402 Kg), and in one embodiment in the range from about 1000 to
about 7500 pounds (454 to 3402 Kg), and in one embodiment about
5000 pounds (2268 Kg). The decontamination unit 100 may be readily
transported using conventional techniques, for example, the
decontamination unit 100 may be transported using an airplane,
ship, truck, and the like. The decontamination unit is positioned
on and may be transported using pallet 128. Pallet 128 may be a
standard military 463L master pallet.
[0019] The 463L master pallet is used for air transport by the
United States Air Force. Cargo aircraft used by the United States
Air Force may be configured to accept these pallets. The 463L
master pallet is also used for combat offloads and aerial delivery
or airdrop. The 463L master pallet is 88 inches (224 cm) wide, 108
inches (274 cm) long, and 2.25 inches (5.7 cm) high. The usable
space is 84 inches (213 cm) by 104 inches (264 cm). The 463L master
pallet may hold up to 10,000 pounds (4500 Kg) of cargo. The empty
weight is 290 pounds (130 Kg). The 463L master pallet has a balsa
wood core which is surrounded by a thin aluminum skin. There are 22
rings surrounding the edge, each rated at 7,500 pounds (3400
Kg).
[0020] The decontamination unit 100 may be used in hostile
environments such as those that may be anticipated for military
applications. When intended for use in such hostile environments
the housing 110 as well as the decontamination chamber 400 may be
ruggedized. Ruggedization may include resistance to anticipated
operating conditions and hazards, including hot and cold
temperatures, exposure to solar radiation, rain, fungus, salt fog,
sand, dust, vibration and/or shock, as well as exposure to CBRN
contaminants. The decontamination chamber 400 may be constructed of
materials capable of withstanding exposure to decontaminants that
may be used in the decontamination chamber 400 as well as the
contaminants likely to be encountered. The decontamination chamber
400 may be insulated. The housing 110 and the decontamination
chamber 400 may be constructed using any material that is
sufficient to provide the apparatus with the desired properties of
strength and yet be sufficiently lightweight to be transportable as
well as being ruggedized. The materials of construction may include
stainless steel, coated steel, aluminum, aluminum alloy, anodized
aluminum, and the like. Various metal alloys may be used, including
the stainless steel alloys SS304 and SS316, and aluminum alloy
6061. Non-reactive materials, such as polyethylene, polyvinyl
chloride, fluorinated polymers such as polytetrafluoroethylene, and
the like, may be used.
[0021] The decontaminant processing section 200 may include power
generator 205 and decontaminant generator 260. The power generator
205 may include internal combustion engine 210 and electric
generator 250. Alternatively, the power generator may comprise a
fuel cell. The decontamination unit 100 may be regarded as being
self-contained due to the fact that all of the power required to
operate the decontaminant generator 260 may be provided by the
power generator.
[0022] The power generator 205 may comprise internal combustion
engine 210 in combination with electric generator 250 as shown in
FIG. 2. The internal combustion engine 210 may comprise any
internal combustion engine that is suitable for providing
sufficient power to operate the electric generator 250. The
internal combustion engine 210 may be operated using diesel fuel,
gasoline, petroleum gas, propane gas, natural gas, liquefied
petroleum gas, hydrogen gas, biofuels (e.g., ethanol, biodiesel
fuel, etc.), and the like. The internal combustion engine 210 may
comprise a spark ignition engine or a compression ignition engine.
The internal combustion engine 210 may comprise a two-cycle engine,
four-cycle engine, rotary engine, or gas turbine engine.
[0023] The electric generator 250 may comprise any electric
generator that can be powered by the internal combustion engine 210
and provide sufficient power to operate the decontaminant generator
260, as well as any other electrically powered equipment used with
the decontamination unit 100 including lighting, electrically
operated blowers, computers, monitors, controllers, recorders, and
the like. The electric generator 250 may have a power rating in the
range from about 4 to about 30 kVA, and in one embodiment in the
range from about 4 to about 20 kVA, and in one embodiment in the
range from about 4 to about 10 kVA.
[0024] The power generator 205 may comprise the internal combustion
engine 210 and the electric generator 250 combined as a single
piece of equipment. The power generator 205 may be ruggedized to
permit use in hostile environments such as those that may be
anticipated for military applications. The power generator may be
sufficiently small and lightweight to allow the decontamination
unit 100 to be transportable.
[0025] An example of a power generator that may be used is
available from Northern Lights under the trade designation NL673L2.
This power generator employs a Lugger L844 engine which is a
vertical, three cylinder diesel engine. The Lugger L844 engine is a
four cycle, liquid cooled, naturally aspirated, overhead valve,
industrial-duty, diesel engine. This engine may operate at 1500 RPM
or 1800 RPM. The AC output of the electric generator may be 6 kW or
5 kW. The specifications and dimensions for this power generator
may be as follows:
TABLE-US-00001 AC Output 6 kW 60 Hz, 1800 RPM, 1 Ph, 1.0 PF,
120-240 V/25A, 120 V/50A 5 kW 50 Hz, 1500 RPM, 1 Ph, 1.0 PF, 220
V/22.7A Engine Displacement 46.4 in.sup.3 (0.76 Itr) Bore/Stroke
2.64/2.83 in (67/72 mm) HP @ RPM 9.9/1800 7.7/1500 Approx. Fuel Use
1800 RPM @ full load 0.59 gph (2.2 lph) 1800 RPM @ full load 0.32
gph (1.2 lph) 1500 RPM @ full load 0.50 gph (1.9 lph) 1500 RPM @
full load 0.28 gph (1.1 lph)
The NL 673L2 power generator may have a base length of 32.8 inches
(83.4 cm), a base width of 15.3 inches (39.40 cm), a height of 27
inches (68.6 cm), and a dry weight of 377 pounds (171 kg).
Additional information concerning this power generator may be found
at
http://www.northern-lights.com/PDFs/brochurepdfs/NL673L2.pdf.
[0026] As an alternative to the internal combustion engine 210 and
electric generator 250, the power generator may comprise a fuel
cell. The fuel cell may be regarded as an electrochemical energy
conversion device. It produces electricity from various external
quantities of fuel (on an anode side) and oxidant (on a cathode
side). These react in the presence of an electrolyte. Generally,
the reactants flow in and reaction products flow out while the
electrolyte remains in the cell. Various combinations of fuel and
oxidant may be used. The fuel call may comprise a hydrogen cell
which uses hydrogen as the fuel and oxygen as the oxidant. Other
fuels may include hydrocarbons and alcohols. Other oxidants may
include air, chlorine and chlorine dioxide. The fuel cell may work
by catalysis, separating the component electrons and protons of the
reactant fuel, and forcing the electrons to travel through a
circuit, hence converting them to electrical power. The catalyst
may comprise a platinum group metal or alloy. Another catalytic
process takes the electrons back in, combining them with the
protons and the oxidant to form waste products (typically water and
carbon dioxide).
[0027] The decontaminant generator 260 may include gas inlet line
262, gas outlet line 264, catalytic converter 266, filter 268,
desiccant wheel 270, blower 272, heater 274, vaporizer 276, liquid
decontaminant container 278, and alkaline gas container 280. The
power to operate the various components of the decontaminant
generator 260 may be provided by the power generator 205.
[0028] In the operation of the decontaminant generator 260, a
gaseous air stream comprising spent gases flows from the
decontamination chamber 400 through line 262 into and through
catalytic converter 266, and from the catalytic converter 266
through filter 268 to desiccant wheel 270, and then from desiccant
wheel 270 to blower 272. The catalytic converter 266 may be used to
destroy residual amounts of the decontaminant that may be in the
gaseous air stream. For example, the catalytic converter 266 may be
use to convert residual hydrogen peroxide to water vapor and
oxygen. The catalyst may comprise any transition metal, transition
metal oxide, or combination thereof, having the desired catalytic
properties. The catalyst may comprise Ag, Mn, Pd, Pt, Rh, an oxide
of one or more of the foregoing metals, or a mixture of two or more
of the foregoing metals and/or oxides. The catalyst may be
supported by a suitable support such as an alumina support. The
catalyst may comprise silver in the form of a screen or screen
plating. The catalyst may comprise a silver based alloy. The
catalyst may comprise manganese dioxide. The catalyst may be in the
form of a bed of particulate solids. The filter 268 may comprise a
carbon filter and a high efficiency particle air (HEPA) filter. The
desiccant wheel 270 may contain a desiccant material such as
lithium chloride, silica gel, molecular sieves, and the like. The
desiccant material may be used to absorb moisture from the gaseous
air stream and thereby dehumidify the gaseous air stream. A
regenerative air stream may flow through the desiccant wheel 270 as
indicated by arrows 282 and 284. The gaseous air stream may flow
from the desiccant wheel 270 through blower 272 to heater 274 where
it may be heated. The gaseous air stream may flow from the heater
274 into vaporizer 276. Liquid decontaminant may flow from liquid
decontaminant container 278 into the vaporizer 276. The liquid
decontaminant may be vaporized in vaporizer 276 and combined with
the gaseous air stream to form the decontaminant air stream. The
decontaminant air may flow out of the vaporizer 276 through line
264. Optionally, an alkaline gas such as ammonia may flow from
alkaline gas container 280, which may be a pressurized cartridge,
to line 264 where it may be combined with the decontaminant air
stream.
[0029] The decontaminant may comprise one or more oxidants such as
peracids (e.g., peracetic acid) and/or peroxides (e.g., hydrogen
peroxide), and the like. Oxidants such as hypochlorites, ozone, and
the like, may be used. Mixtures of two or more of these may be
used. Aqueous solutions of these oxidants may be used. The
decontaminant may be combined with a solvent. The solvent may be
miscible with water. When the decontaminant comprises hydrogen
peroxide, the solvent may be used to enhance the solubility of the
hydrogen peroxide and its associated decomposition products in the
contaminant and thereby enhance the rate of destruction of the
contaminant. The solvent may comprise a mixture of water and
tert-butyl alcohol; water and acetonitrile; or water, acetonitrile
and isopropyl alcohol. Other suitable solvents may include
tetrahydrofuran, dimethylsulfoxide, acetone, acetaldehyde,
propylene oxide, acetamide, diethylamine, dimethoxyethane, or a
mixture of two or more thereof. The solvent concentration in the
combined mixture of decontaminant and solvent may be in the range
up to about 60% by weight solvent, and in one embodiment in the
range from about 20 to about 60% by weight solvent. The
decontaminant may be combined with an alkaline gas such as ammonia
in applications wherein an increase in the pH of the decontaminant
may be desired.
[0030] Vaporous hydrogen peroxide (VHP), which may be generated
from an aqueous solution of hydrogen peroxide, may be used as the
decontaminant. The aqueous solution may comprise from about 30% to
about 40% by weight hydrogen peroxide, and in one embodiment about
35% by weight hydrogen peroxide; and from about 60% to about 70% by
weight water, and in one embodiment about 65% by weight water. By
adding an alkaline gas that is soluble in the hydrogen peroxide
(ammonia, for example), the pH of the decontaminant may be
controlled. The volumetric ratio of VHP to ammonia gas may be in
the range from about 1:1 to about 1:0.0001.
[0031] VHP, when used in combination with ammonia gas, may be
referred to as modified VHP or mVHP. VHP and/or mVHP may be
effective microbial and chemical decontaminants because they may
provide a broad spectrum of activity against a wide variety of
pathogenic microorganisms and chemical pathogenic agents, such as
hard to destroy spores of Bacillus stearothermophilus, Bacillus
anthracis, smallpox virus, and the like. They may be also effective
at or close to room temperature (e.g., about 15 to about 30.degree.
C.), making them suitable for use in the decontamination chamber
400 with little or no heating. VHP and/or mVHP may have good
material compatibility, rendering them safe for use with a variety
of equipment and materials, including electronic equipment, soft
furnishings, brass and chrome fixtures, and the like. VHP may
degrade to water and oxygen over time, which may not be harmful to
a person subsequently entering the decontamination chamber 400. Low
levels of hydrogen peroxide (for example, about 1 ppm, or less)
that may remain in the decontamination chamber 400 after the
decontamination process has been completed may not be considered to
pose a risk to a person entering the chamber.
[0032] The decontamination chamber 400 may be referred to as a
double-door decontamination chamber. The decontamination chamber
400 may have a first entrance 420 with a first door 425, and an
opposite second entrance 430 with a second door (not shown). The
first entrance 420 may be referred to as the "contaminated" side of
the decontamination chamber and the second entrance 430 may be
referred to as the "clean" side of the decontamination chamber. A
loading cart 440 may be used to load contaminated articles into the
decontamination chamber and unload decontaminated articles from the
decontamination chamber 400. The decontamination chamber 400 may be
operated by placing the contaminated articles on the loading cart
440. The first door 425 on the contaminated side 420 of the
decontamination chamber 400 may be opened and the cart may be
rolled into the decontamination chamber 400. The first door 425 may
then be closed.
[0033] The decontaminant air stream may flow from the decontaminant
processing section 200 into the decontamination chamber 400. The
decontaminant air stream may circulate in the interior of the
decontamination chamber 400, contact contaminated articles
positioned in the decontamination chamber 400, and decontaminate
the contaminated articles. A gaseous air stream comprising spent
gases (i.e., air, residual decontaminant, residual hazardous
biological and/or chemical materials, etc.) may flow from the
decontamination chamber 400 back to the decontaminant air
processing section 200. The decontamination process may be
controlled using control unit 320. The decontamination chamber 400
may include one or more internal blowers for circulating gas in the
decontamination chamber 400. The blowers may be powered by the
power generator 205. The decontamination chamber 400 may contain
internal monitors for measuring decontaminant levels, temperature,
internal gas flow, and the like. These monitors may be used in
combination with controllers for adjusting decontaminant
concentration levels, temperature, internal gas flow rates, and the
like.
[0034] When the decontaminant air stream flows into the
decontamination chamber 400 and contacts the contaminated articles
to be decontaminated, the process may be regarded as a dry process
characterized by the absence of condensate formation on the
surfaces of the contaminated articles being decontaminated.
Alternatively, the process may be regarded as a wet process
characterized by the formation of a condensate in the form of a
liquid film on the surfaces of the contaminated articles. The
liquid film may have a film layer thickness in the range up to
about 20 microns, and in one embodiment up to about 10 microns, and
in one embodiment up to about 5 microns, and in one embodiment up
to about 1 micron. The film layer may be referred to as a
microcondensate layer of hydrogen peroxide.
[0035] The progress of the decontamination process may be monitored
using one or more decontamination or sterilization indicators.
These indicators may contain a biological indicator. The biological
indicator may comprise one or more test organisms which may be more
resistant to the decontamination process than the organisms to be
destroyed by the decontamination process. The test organism may be
placed in contact with an incubation medium to determine whether
the decontamination process was effective.
[0036] Upon completion of the decontamination process, the second
door on the clean side 430 of the decontamination chamber may be
opened and the loading cart 440 may be rolled out and unloaded.
[0037] The loading cart 440 may have any desired shape and design
so long as it is suitable for traveling into and out of the
decontamination chamber 400, and being held in the decontamination
chamber 400 during operation of the decontamination process and/or
transport of the decontamination unit 100. The loading cart 440, as
depicted in the drawings, includes a number of solid shelves, and
open sides. Alternatively, each of the shelves may be perforated or
grated. The perforated or grated shelves may be advantageous for
permitting internal circulation of the decontaminant air stream
within the decontamination chamber 400. The loading cart 440 may
have sidewalls which may be solid or they may be perforated or
grated. The loading cart 440 may not have any shelves, and it may
optionally have sidewalls that may be solid or may be perforated or
grated.
[0038] The loading cart 440 may be positioned on platform frame
450, which may be located in front of the contaminated side 420 of
the decontamination chamber 400, while the loading cart is loaded
with contaminated articles. The platform frame 450 includes tracks
452 which are adapted for supporting the wheels 442 of the cart
440. The loading cart 440 may be pushed into the decontamination
chamber 400 after which the door 425 may be closed and the
decontamination process commenced. The decontamination chamber 400
includes interior tracks 457 which are provided to permit a
facilitated and stabilized movement of the loading cart 440 into
and out of the decontamination chamber 400, Upon completion of the
decontamination process, the door on the clean side of the
decontamination chamber 400 may be opened and the loading cart 440
may be rolled out of the decontamination chamber 400 on platform
frame 454. The platform frame 454 includes tracks 456 for
supporting the cart wheels 442. The platform frames 450 and 454 may
include notched brackets 458 which are adapted to engage knobs 459
which are mounted on sides of the interior tracks 457. The
resulting locking mechanisms allow the portable platform frames 450
and 454 to be releasably attached to the contaminated and clean
sides of the decontamination chamber 400. This provides for the
portable tracks 452 and 456 to be properly aligned with the
interior tracks 457. It will be understood by those skilled in the
art that a single platform frame may be used rather than the two
platform frames 450 and 454 discussed above. The single platform
frame may be used on the contaminated side during loading, and then
on the clean side during unloading. The loading cart 440 and the
platform frames 450 and 454 may be stored in the decontamination
chamber 400 while the decontamination unit 100 is being
transported. Alternatively, the platform frames 450 and 454 may be
mounted on top or on the side of the decontamination unit 100
during transport of the decontamination unit.
[0039] The temperature of the decontaminant air stream entering the
decontamination chamber 400 may be in the range from about
10.degree. C. to about 50.degree. C., and in one embodiment in the
range from about 15.degree. C. to about 50.degree. C., and in one
embodiment in the range from about 15.degree. C. to about
30.degree. C. The relative humidity of the decontaminant air stream
entering the decontamination chamber 400 may be in the range from
about 0 to about 50%, and in one embodiment in the range from about
20 to about 40% by volume. The term "relative humidity" is used
herein to refer to the ratio of the partial pressure of water vapor
in the decontaminant air stream to the saturated vapor pressure of
water at the temperature of the decontaminant air stream expressed
in terms of percentage.
[0040] The concentration of decontaminant in the decontaminant air
stream entering the decontamination chamber may be in the range
from about 0.01 to about 2% by volume, and in one embodiment in the
range from about 0.01 to about 1.5% by volume, and in one
embodiment in the range from about 0.01 to about 1% by volume, and
in one embodiment in the range from about 0.01 to about 0.5% by
volume, and in one embodiment in the range from about 0.02 to about
0.2% by volume, and in one embodiment in the range from about 0.02
to about 0.05% by volume. When the decontaminant comprises solvent,
the concentration of decontaminant plus solvent in the
decontaminant air stream entering the decontamination chamber may
be in the range from about 0.01 to about 2% by volume, and in one
embodiment in the range from about 0.02 to about 0.08% by volume.
When the decontaminant comprises an alkaline gas, the concentration
of alkaline gas in the decontaminant air stream entering the
decontamination chamber may be in the range from about 0.001 to
about 0.01% by volume, and in one embodiment in the range from
about 0.003 to about 0.005% by volume. The gas flow rate through
the decontamination chamber 400 may be in the range from about 5 to
about 40 cubic feet per minute (CFM) (0.14 to 1.13 cubic meters per
minute (CMM)), and in one embodiment in the range from about 10 to
about 20 CFM (0.28 to 0.57 CMM). The temperature within the
decontamination chamber may be in the range from about 10.degree.
C. to about 50.degree. C., and in one embodiment in the range from
about 15.degree. C. to about 50.degree. C., and in one embodiment
in the range from about 15.degree. C. to about 30.degree. C. The
operating pressure within the decontamination chamber 400 may be
slightly negative to prevent the leakage of contaminants and
decontaminants from the decontamination chamber 400. The internal
pressure may be in the range of up to about 10 inches of water
below atmospheric pressure, and in one embodiment in the range from
about 0.01 to about 5 inches of water, and in one embodiment in the
range from about 0.01 to about 2 inches of water, and in one
embodiment in the range from about 0.01 to about 1 inch of water,
and in one embodiment in the range from about 0.01 to about 0.5
inch of water, and in one embodiment in the range from about 0.01
to about 0.3 inch of water below atmospheric pressure.
[0041] The contaminated articles may be contaminated with any
contaminant. The articles may comprise any article that may be
stored in the decontamination chamber 400. These may include
military weapons, clothing, and body armor, as well as sensitive
equipment such as computers, test equipment, optical devices,
electronic devices, communications equipment, and the like. The
contaminant may comprise one or more chemical, biological,
radiological and/or nuclear (CBRN) warfare agents.
[0042] Different levels of decontamination may be accomplished
within the decontamination chamber 400. As used herein, the term
"decontamination," is intended to encompass both microbial
decontamination as well as chemical decontamination--the
destruction of chemical agents, or their conversion to harmless or
odorless compounds. Decontamination may also encompass the
neutralizing of unpleasant odors, such as tobacco smoke, perfume,
or body odor residues, and odors and dampness due to molds.
"Microbial decontamination" may be used herein to encompass the
destruction of biological contaminants, specifically, living
microorganisms, and also the destruction or inactivation of
pathogenic forms of proteinaceous-infectious agents (prions). The
term microbial decontamination encompasses sterilization, the
highest level of biological contamination control, which connotes
the destruction of all living microorganisms. The term also
includes disinfection, the destruction of harmful microorganisms,
and sanitizing, which connotes being free from germs. "Chemical
decontamination" is intended to encompass the destruction of
pathogenic chemical agents or their conversion to less harmful or
odiferous species.
[0043] Exemplary biological contaminants which may be destroyed in
the decontamination process include bacterial spores, vegetative
bacteria, viruses, molds, and fungi. Some of these may be capable
of killing or causing severe injury to mammals, particularly
humans. Included among these are viruses, such as equine
encephalomyelitis and smallpox, the coronavirus responsible for
Severe Acute Respiratory Syndrome (SARS); bacteria, such as those
which cause plague (Yersina pestis), anthrax (Bacillus anthracis),
and tularemia (Francisella tularensis); and fungi, such as
coccidioidomycosis; as well as toxic products expressed by such
microorganisms; for example, the botulism toxin expressed by the
common Clostridium botulinium bacterium.
[0044] Also included are the less harmful microorganisms, such as
those responsible for the common cold (rhinoviruses), influenza
(orthomyxoviruses), skin abscesses, toxic shock syndrome
(Staphylococcus aureus), bacterial pneumonia (Streptococcus
pneumoniae), stomach upsets (Escherichia coli, Salmonella), and the
like.
[0045] Exemplary pathogenic chemical agents may include substances
which are often referred to as chemical warfare agents, such as
poison gases and liquids, particularly those which are volatile,
such as nerve gases, blistering agents (also known as vesicants),
and other extremely harmful or toxic chemicals. As used herein, the
term "chemical pathogenic agent" is intended to include only those
agents which are effective in relatively small dosages to
substantially disable or kill mammals and which can be degraded or
otherwise rendered harmless by a process which includes
oxidation.
[0046] Exemplary chemical pathogenic agents may include choking
agents, such as phosgene; blood agents, which act on the enzyme
cytochrome oxidase, such as cyanogen chloride and hydrogen cyanide;
incapacitating agents, such as 3-quinuclidinyl benzilate ("BZ"),
which blocks the action of acetylcholine; vesicants, such as
di(2-chloroethyl) sulfide (mustard gas or "HD") and
dichloro(2-chlorovinyl)arsine (Lewisite); nerve agents, such as
ethyl-N, N dimethyl phosphoramino cyanidate (Tabun or agent GA),
o-ethyl-S-(2-diisopropyl aminoethyl) methyl phosphono-thiolate
(agent VX), isopropyl methyl phosphonofluoridate (Sarin or Agent
GB), methylphosphonofluoridic acid 1,2,2-trimethylpropyl ester
(Soman or Agent GD).
[0047] While the disclosed invention has been explained in relation
to various detailed embodiments, it is to be understood that
various modifications thereof may become apparent to those skilled
in the art upon reading the specification. Therefore, it is to be
understood that the invention specified herein is intended to
include such modifications as may fall within the scope of the
appended claims.
* * * * *
References