Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02642162 2008-10-27
PORTABLE AND COLLAPSIBLE CHEM. / BIO. ISOLATORS
CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority right of prior United States patent
application 60/983,717 filed October 30, 2007 by applicants herein.
FIELD OF THE INVENTION
The present invention relates to isolators for use in containing, handling
and transporting potentially hazardous radioactive, chemical or biological
agents.
Background of the Invention
On-site handling and containment of suspicious packages or known
hazardous materials poses an enormous risk to both the initial responders who
must contain and transport the materials and subsequent investigators who must
handle the materials to determine their origin, composition, risk and eventual
disposal. In particular, hazardous radioactive, chemical and biological agents
pose an increased threat. These agents may include, but are not limited to,
chemical warfare agents, toxins, Risk Group 3 and Risk Group 4 biological
pathogens and can also include radioactive materials.
Isolators used to contain such agents are required by law to be airtight to
prevent escape of any potentially hazardous material. Furthermore, such
isolators must be fitted with negative pressure ventilation systems and high
efficiency particulate air (HEPA) filters. All ports attached to the isolator
must
be sealable against leaks. They further require isolation of a researcher from
the
pathogen and decontamination of air and other effluents produced in the
facility.
Traditionally, isolators used for containing such agents have been made
of glass and stainless steel, to provide the containment requirement listed
above.
However, such isolators are often heavy and cumbersome. Transportation of
such isolators can be very difficult and they cannot generally be used in any
portable capacity. Furthermore, conventional isolators require elaborate on-
site
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assembly and decontamination before disassembly which detrimentally adds to
response time and can increase public exposure to the potentially harmful
substances.
US patent nos. 6,974,197, 6,715,343 and 6,428,122 all to Henry et al.,
teach portable containment systems for chemical and biological materials.
However these must be assembled from numerous pieces and then later
decontaminated fully before being dismantled for storage and transport. It is
a
challenge to conveniently transport these isolators in a fully assembled
condition.
US patent 5,864,767 teaches a containment system for chemical and
biological explosive devices. This system is meant to contain explosive blast
over-pressure and blast fragmentation particles caused by an explosive blast.
However, the device is not airtight, and in fact is taught to have an open
base
and therefore can not isolate radioactive, biological or chemical agents from
the
surrounding environment.
The need thus remains for a device which can contain and isolate
hazardous biological and chemical materials which is easier to manage and
transport.
SUMMARY OF THE INVENTION
The present invention provides a collapsible and portable chemical and
biological isolator that can be deployed in a short amount of time.
More particularly, certain exemplary embodiments provide a portable
and collapsible isolator for isolating and containing radioactive, chemical or
biological agents, comprising a collapsible frame, movable between a collapsed
transport position and an open operational position, a flexible and
collapsible
envelope in the form of an airtight bag attached to the frame to define a
cavity,
wherein said envelope remains airtight in both collapsed and open positions,
one or more sealable openings formed in the envelope for insertion and removal
of the radioactive, chemical or biological agents into and out of the cavity
and
optionally one or more gloves extending from one or more of said sealable
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openings, for handling said radioactive, chemical and biological agents inside
the cavity.
Further exemplary embodiments provide a portable and collapsible
isolator for containing radioactive, chemical or biological agents comprising
a
collapsible frame, movable between a collapsed transport position and an open
operational position and a flexible and collapsible envelope in the form of an
airtight bag attached to the frame to define a cavity, wherein said envelope
remains airtight in both collapsed and open positions. One or more sealable
openings are formed in the envelope for insertion and removal of the
radioactive, chemical and biological agents into and out of the cavity and
optionally one or more gloves extending from one or more of said sealable
openings into the cavity, for handling said radioactive, chemical and
biological
agents inside the cavity. A base structure in the form of a first lockable
carrying
case is connected to one or more surfaces of the envelope or the frame. The
base structure is movable between a collapsed, transportable position and an
open, operational position.
Further exemplary embodiments provide a portable and collapsible
isolator for containing radioactive, chemical or biological agents, comprising
a
top structure, a table top, upon which the top structure rests and a base
structure
upon which the table top rests. The top structure comprises a collapsible
frame,
movable between a collapsed transport position and an open operational
position and a flexible and collapsible envelope in the form of an airtight
bag
attached to the frame to define a cavity, wherein said envelope remains
airtight
in both collapsed and open positions. One or more sealable openings are formed
in the envelope for insertion and removal of the radioactive, chemical or
biological agents into and out of the cavity and optionally one or more glove
extending from one or more of said sealable openings into the cavity, for
handling said radioactive, chemical and biological agents inside the cavity.
The
said base structure may comprise a base frame of four telescopic legs that are
extendable for operation or collapsible for transportation.
BRIEF DESCRIPTION OF THE DRAWINGS
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Preferred embodiments of the present invention are described below, in
conjunction with the accompanying figures, wherein:
Figure 1 is a perspective view of one exemplary embodiment of a portable and
collapsible isolator.
Figure 2 is a perspective view of one exemplary embodiment of a portable and
collapsible isolator.
Figure 3 is a perspective view of one exemplary embodiment of a portable and
collapsible isolator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a portable and collapsible isolator for
containing and handling hazardous or potentially hazardous radioactive,
chemical or biological agents that may possibly pose a threat to public health
and safety. For the purposes of the present disclosure, radioactive, chemical
and biological agents may include, but are not limited to, chemical warfare
agents, toxins, Risk Group 3 and Risk Group 4 biological pathogens, as well as
some radioactive materials. Such agents can include, among others, hydrogen
cyanide, cyanogens chloride, phosgene, Lewisite, Mustard gas, G-series nerve
agents, Ricin, VX nerve agent and radioactive iodine. Furthermore, the present
isolator is capable, at least in selected embodiments, of containing particles
that
may be Alpha or Beta emitters.
One embodiment is shown in Figure 1 in which there is illustrated a
collapsible and portable isolator 10 comprising as the main components a
collapsible frame 2, a clear, flexible and collapsible envelope 4 in the form
of
an airtight bag attached to the frame to define a cavity 6 and one or more
sealable openings 8 forrned in the envelope 4 for insertion and removal of the
radioactive, chemical or biological agents into and out of the cavity.
Optionally, one or more, and preferably two, of the sealable openings are
equipped with gloves (not shown), which extend into the cavity, for handling
the agents in question. Most preferably the gloves have two-piece cone shape
sleeves to allow for various hand sizes to uses the device, while always
maintaining containment.
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The sealable openings 8 may have bag in/bag out capabilities which are
well known in the art. In particular the sealable openings may be fitted with
a
long sleeve or tube (not shown) optionally made of the same material as the
envelope 4, so that suspicious packages can be inserted into and taken out of
the
isolator without jeopardizing containment. The sealable openings 8 are
preferably sized to accommodate standard examination equipment such as, for
example, light microscopes, hazardous materials HazMat detectors and
radiation detectors.
To meet containment requirements, the isolator 10 may be outfitted with
or associated with an inlet and an outlet air filtration system (not shown)
mechanically attached to and sealed against the flexible envelope 4, to filter
air
entering and leaving the isolator. Preferably, the inlet air filtration system
comprises single or double High Efficiency Particulate Air (HEPA) filters and
outlet air filtration system comprises single or double double High Efficiency
Particulate Air (HEPA) filters. The inlet air filter is preferably protected
from
backflow by use of a check-valve. The outlet air filtration system preferably
also comprises a carbon filter such as a double-carbon filter to absorb any
fugitive chemical vapours. More preferably, the HEPA filters preferably have a
minimum efficiency of 99.99% on particles of 0.3 m size or greater.
The air filtration systems are connected to a variable speed blower motor
which draws clean air in through the inlet filtration system and out through
the
outlet filtration system and is operated in a negative pressure mode to
provide a
negative pressure inside the cavity. Negative pressure is preferred to ensure
that, in the event of a leak in the isolator system, fresh air from outside
the
system will flow into the isolator, rather than potentially contaminated air
flowing out to the surrounding atmosphere. Preferably, the filtration systems
are operated to create a negative pressure of -0.2 inches of water gauge (-
0.05
kPa), more preferably -0.5 inches of water gauge (-0.125 kPa).
The frame 2 of the isolator preferably comprises telescopic frame
members that can be collapsed for transportation. The flexible envelope 4 can
be attached to the frame in a number of known ways in the art, including but
not
limited to use of Velcro loops, grommets and tabs. As an example, Fig. 1
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illustrates the use of loops 12 made of the same material as the envelope and
welded to the envelope for attaching the envelope 4 to the frame 2. The
envelope 4 remains attached to the frame 2 in both the collapsed and open
positions. The envelope 4 provides a completely airtight cavity 6 in which the
radioactive, chemical and biological agents are stored. The envelope 4 retains
its air tightness in both the collapsed and open positions of the isolator, so
that,
size permitting, the agents in question can be stored and transported when the
isolator is collapsed. Furthermore, no decontamination of the cavity of the
envelope is required before collapsing and transporting the isolator. The
envelope has no joints or breaks in the structure to help avoid leaks. The one
or
more sealable openings 8 are also airtight and any mechanical closures formed
on the envelope are of a design commonly used in glove-box systems, and are
airtight as well.
Optionally, the envelope 4 may be disposed of after a number of uses,
and replaced with another envelope. In a further preferred embodiment, the
envelope 4 may be removed from the frame without compromising the integrity
of the envelope, so that disposal and replacement of the envelope 4 does not
expose the cavity 6 to the surrounding environment.
The envelope 4 may be made of a clear or translucent material, or may
be an opaque membrane fitted with clear windows. The envelope 4 is
preferably at least semi-flexible and resistant to attack by radioactive,
chemical
and biological agents. The envelope material is preferably weldable to itself
to
ensure air tightness. Through extensive testing and investigation, the present
inventors have found that certain multi-layer, clear, laminate barrier
materials
are particularly suitable for use as envelope material. For example, a
lamination
of nylon, ethylene-vinyl alcohol copolymer (EVOH), and polyethylene (PE) has
been found to work well. Another exarnple is a lamination of polyester, nylon,
EVOH and PE. In these laminates, the nylon and EVOH serve as barriers to the
radioactive, chemical or biological agents as well as to humidity and oxygen
and may face the inside of the isolator cavity. The polyethylene serves to
render the various layers of the laminate weldable to each other and also
forms
the outside layer of the envelope. Such a laminate also maintains high
integrity
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over a range of environmental temperatures and can operate in a range of
temperatures from -15 C to +40 C or beyond. As indicated above, the envelope
4 can be disposable and replaced with a new envelope after a number of uses.
Most preferably, the envelope is replaced after a dozen open and close cycles
of
the sealable openings 8.
Auxiliary systems of the isolator, if present, may include a monitoring
system comprised of, for example, a Magnehelic or other differential low air
pressure indicator to monitor pressure inside the cavity, and/or audio and
visual
warning devices to indicate low or high interior pressure, and/or low battery.
Furthermore, the isolator may optionally be connected to a power source,
preferably both AC and DC power sources can be used. A battery pack may
also be optionally provided as the sole power source or as an additional power
source.
Further embodiments of the present invention are disclosed herein to
serve different requirements for portability and use. One further embodiment
of
the isolator is illustrated in Fig. 2. Another embodiment of the isolator is
illustrated in Fig. 3.
With reference to Fig. 2, the isolator is shown generally at 14. The
frame 2 is collapsible into and containable within a first lockable carrying
case
16 for transportation or storage purposes. In this embodiment, the isolator 14
has dimensions and a weight such that it can be transported by a single
person.
For example, the isolator may weigh about 50 pounds or less (22.6 kg) and have
a height of from 24" to 30" (609 to 762 mm), a length of 24" to 40" (609 to
1026 mm) and a depth of 24" to 30" (609 to 762 mm). In this first preferred
embodiment, the isolator 14 is preferably used for onsite containment of
smaller
suspicious packages or smaller amounts of materials, which can be examined on
site or can be contained in the isolator even when the first lockable carrying
case 16 is closed and carried to another location for further investigation.
The case 16 is preferably made of a rigid, lightweight material
optionally including one or more handles (not shown) so that it can be
transported by a single person. Most preferably, the carrying case is a hard
sided case. When the isolator is in the open, operating position, the walls of
the
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carrying case may serve as a rigid bottom surface 18 and a back wa1120 to the
isolator. The bottom surface 18 of the carrying case is preferably flat and
outfitted with no-slip pads to ensure stability of the isolator if it is
placed on a
desk, stand or other level surface. Alternatively, foldable, telescopic legs
22
may extend from the bottom surface 18 of the carrying case 16 to allow the
isolator to be self-standing and self-leveling. When the telescopic legs 22
are
not used, they can be collapsed and folded into recesses (not shown) formed in
the bottom surface 18 of the carrying case or detached and carried separately.
Since the isolator 14 of Fig. 2 and its carrying case 16 require no
disassembly, the case can simply be closed after use and transported away. No
on-site decontamination is necessary since the internal cavity of the isolator
is
not exposed. This avoids dangerous exposure to personnel onsite and allows
for rapid site decommissioning once the package has been handled.
Preferably, the blower motor and the auxiliary systems are contained in
a second lockable carrying case (not shown). The second lockable carrying case
is also preferably dimensioned to be transportable by a single person, and
preferably weighs less than 50 pounds (22.6 kg).
The isolator shown at 24 in Fig. 3, is generally larger than that shown in
Fig. 2 and can be used for containment, handling and investigation of larger
suspicious packages or larger amounts of materials. The isolator 24 shown in
Fig. 3 is also designed to be compact and transportable. The isolator 24
comprises a top structure 26, a table top 28 and a base structure 30. The top
structure 26 comprises all of the elements listed previously for the isolator
14
shown in Figure 2. The frame 2 is made of a lightweight tubing material fitted
with removable end connections. The side portions 32 of the frame 2 are
jointed to the table top 28 with pivoting joints 34 so that the side portions
32
can pivot inwards and collapse onto the table top 28 for transportation. The
transverse members 36 of the frame 2 are removable for storage in the base
structure 30. It will be noted that the envelope 4 of the isolator remains
intact
during disassembly of the frame 2 and therefore any substances contained
therein are never exposed to the outside environment even during collapsing
and transporting the isolator.
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The base structure 30 may comprise a base frame of four telescopic legs
38 that can be extended to a comfortable work height for operation or lowered
for transportation. Alternatively, the legs 38 comprise hydraulic cylinders
for
collapsibility. Casters 40 are fitted to the bottom of the base structure 30
to
allow the isolator 24 to be easily transported from place to place. The
castors
40 are preferably fitted with pivotable plates (not shown) to permit the
isolator
to rest on the plates and maintain stable contact with the ground during use.
The base structure 30 may house all auxiliary systems 42 for the isolator,
including the filtration system, blower motor, monitoring and electrical
systems.
The table top 28 supports the top structure 26 on the base structure 30
and is preferably made of stainless steel supporting a flat surface plate,
most
preferably a 1/2" thick plastic plate.
The isolator 24 of Fig. 3 may weigh, for example, about 500 pounds
(22.6 kg) with a height of from 40" to 65" (1000 to 1651 mm), a length of from
65" to 95" (1651 to 2438 mm) and a depth of from 24" to 65" (609 to 1651
mm), when deployed.
Since collapsing the isolator 24 of Fig. 3 does not require disassembly of
the envelope 4 in any way, the frame 2 and base structure 30 can simply be
collapsed after use and transported with the envelope intact. No on-site
decontamination is necessary since the cavity 6 of the isolator is never
exposed
to the atmosphere. This avoids dangerous exposure for personnel and allows
for rapid site decommissioning once the package has been handled.
The entire isolator system 24 of Fig. 3, once collapsed, can be covered
by a protective cover (not shown) which latches into brackets (not shown)
fitted
near the bottom of the base structure 30. Once collapsed and covered, the
isolator 24 can be rolled away by gripping handles affixed to the cover. The
collapsed and covered isolator 24 can fit easily into a standard mini-van
vehicle.
This detailed description of the apparatus and processes of the present
invention is used to illustrate the prime embodiments of the present
invention.
It will be apparent to those skilled in the art that various modifications can
be
made in the present devices and that various alternative embodiments can be
utilized. Therefore, it will be recognized that modifications can be made in
the
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present invention without departing from the scope of the invention, which is
limited only by the appended claims.
