Title of Invention

MULTI-CLASS FIRE EXTINGUISHING AGENT

Abstract The present invention relates to a fire extinguishing agent comprising: a foam; and at least one inert gas combined with the foam; wherein the at least one inert gas comprises at least one of helium and argon, and the fire extinguishing agent does not comprise an oxidizer, nitrogen, carbon dioxide, halomethanes, fluorine, chlorine, or sulfur. The invention also provides a method of extinguishing a fire comprising combining a foam and at least one inert gas to form a fire extinguishing agent, and applying the fire extinguishing agent to the fire, to extinguish the fire.
Full Text


DESCRIPTION OF THE INVENTION
Related Application
[001] This application claims the benefit of priority under 35 U.S.C.
§ 119(e) of U.S. Provisional Application No. 60/656,436, filed on February 25,
2005, the disclosure of which is incorporated herein by reference.
Field of the Invention
[002] The present invention relates to a fire extinguishing agent. In
particular, the present invention relates to a fire extinguishing agent for
extinguishing multiple classes of fires.
Background of the Invention
[003] Many metals and metal compounds are flammable. When ignited, a
metal may act as the fire's fuel and may be oxidized by a number of elements
and/or compounds. Most metals prone to ignite may produce fires of extremely
high temperatures and may be difficult to extinguish. The classification for fires
involving metals and/or metal compounds are commonly known as "Class D" fires.
Examples of these metals include, but are not limited to, lithium, sodium,
potassium, rubidium, cesium, francium, beryllium, titanium, uranium, and plutonium.
Some metal compounds, such as, for example, alkyllithiums, Grignards and
diethylzinc, are pyrophoric organometalic reagents. Most pyrophoric organometalic
reagents may burn at high temperatures and may react violently with, for example,
water, air, and/or other chemicals.
[004] Because these materials react to produce extremely high
temperature fires and are natural catalysts, they have the ability to extract oxidizers
from their surrounding environment and/or from compounds normally used as fire
extinguishing agents. These oxidizing agents are not necessarily oxygen-
containing compounds. Many metals, such as, for example, magnesium, sodium,


lithium, and potassium, once ignited, will bum in, for example, gases containing
nitrogen, chlorine, fluorine, sulfur, and/or sulfur. The gases may disassociate
common fire extinguishing agents, such as, for example, carbon dioxide and
Halon® to free radicals needed to support their combustion.
[005] One example of how reactive these metals are is demonstrated by
the modern aircraft flare. This type of flare is not compounded from traditional
oxidizers such as potassium nitrate or potassium chlorate, which are rich in oxygen,
but are in fact a mixture of finely powdered magnesium and Teflon®. Teflon® is
considered to be one of the least reactive materials known to man and contains no
oxygen. Once ignited, however, Teflon® decomposes to release fluorine, which
acts as its oxidizing agent. The reaction tends to be more vigorous and tends to
produce temperatures hotter than would be possible with oxygen.
[006] When water comes into contact with some of these metals, such as,
for example, lithium, sodium, potassium, and magnesium, hydrogen gas is
dissociated from the water and a hydroxide radical is formed. The hydrogen gas
formed by this reaction is a very combustible gas and may be often ignited by heat
generated by the decomposing metal/water reaction. In such reactions, a
dangerous situation may result if certain chemicals used in fire extinguishers are
applied to certain types (e.g., classes) of fires. In fact, some dangerous situations
are sometimes associated with the above reactions. For example, some fire
fighting training manuals include warnings such as, for example, the following
warning: "It is vital to know what type of extinguisher you are using. Using the
wrong type of extinguisher for the wrong type of fire can be life-threatening."
[007] When metals and/or metal compounds are shipped from one
location to another, they may often be shipped in containers and/or on pallets with
other types of freight, such as, for example, plastic parts and/or paper boxes. The
resulting mixture of freight types, if involved in a fire, may likely require different
types of fire extinguishing agents in order to effectively extinguish the different
classes of fires (e.g., Class A, Class B, and/or Class D fires).
[008] Fire extinguishing agents sometimes used to safely extinguish Class
D fires (e.g., those types of fires sometimes associated with metals and/or metal
compounds) may not be desirable for extinguishing other classes of fires. As a
result, such agents may require adherence to special procedures for effective use,

such as the following procedure for using an agent sold under the trade name,
"Purple K®": "Apply the dry powder. Completely cover the burning metal with a
thin layer of powder. Once control is established, take a position that is in close
range. Throttle the stream with the nozzle valve to produce a soft, heavy flow.
Cover the metal completely with a heavy layer of powder. Be careful not to break
the crust formed by the powder. Slowly open the nozzle of the extinguisher."
[009] When shipping a mixture of types of freight (e.g., metals and/or
metal compounds, plastic materials, and/or paper boxes), however, it may not be
possible to follow such rules, for example, because it may not be practical to orient
the freight in a manner where freight containing metals and/or metal compounds
would be positioned in such a way to allow the fire extinguishing agent (e.g., fire
extinguishing powder) to cover all exposed sides of that type of freight. For
example, if a container of metallic sodium were shipped, it might be loaded high on
or in the middle of a built-up pallet load of other freight contained in cardboard
boxes. As the cardboard boxes burn during a fire, the freight load might constantly
shift and thereby re-expose the burning sodium following coverage with
extinguishing powder. Further, because of sodium's low melting point, the sodium
might simply melt and run out from under the powdered agent.
[010] Freight shipments sometimes referred to as "Hazardous Freight"
shipments may often include a mixture of types of materials. As a result, if such a
freight shipment were to catch fire, it might generate various classes of fires (e.g.,
Class A, Class B, and/or Class D fires). No single conventional fire extinguishing
agent, however, exists that is desirable for extinguishing all such classes of fires. In
most situations, for example, attempting to extinguish a mixed class fire, including a
Class D fire along with a Class A and/or a Class B fire, may be futile due, for
example, to the differing needs of fire extinguishing agents for different fire classes.
For example, if active elements such as Halon® and/or one of the known Halon®
replacement agents are used to extinguish a Class D fire, a dangerous situation
might result.
[011] There may exist a need for a fire extinguishing agent that may be
used to effectively and/or safely extinguish a fire including burning metals and/or
metal compounds. Further, there may exist a need for a fire extinguishing agent


that may be used to effectively and/or safely extinguish a fire including burning
metals and/or metal compounds along with other types of burning materials.
[012] The invention may seek to satisfy one or more of the
above-mentioned needs. Although the present invention may obviate one or more
of the above-mentioned needs, it should be understood that some aspects of the
invention might not necessarily obviate them.
SUMMARY OF THE INVENTION
[013] In the following description, certain aspects and embodiments will
become evident. It should be understood that the invention, in its broadest sense,
could be practiced without having one or more features of these aspects and
embodiments. It should be understood that these aspects and embodiments are
merely exemplary.
[014] In one aspect, as embodied and broadly described herein, the
invention includes a fire extinguishing agent that may include a foam and at least
one inert gas combined with the foam.
[015] As used herein, the term "inert gas" means at least one gas selected
from helium, neon, argon, krypton, xenon, and radon in concentrations greater than
concentrations naturally occurring in air (e.g., concentrations normally associated
with commercially-available bottled, inert gas).
[016] In another aspect, the invention includes a method of extinguishing a
fire including a burning metal and/or a burning metal compound. The method may
include combining a foam and at least one inert gas to form a fire extinguishing
agent, and applying the fire extinguishing agent to the fire.
[017] According to a further aspect, the invention includes a method of
extinguishing a fire including a burning metal and/or a burning metal compound and
also including a burning plastic material and/or a burning paper material. The
method may include combining a foam and at least one inert gas to form a fire
extinguishing agent, and applying the fire extinguishing agent to the fire.
[018] In still a further aspect, the invention includes a method of
extinguishing a fire including a Class D fire. The method may include combining a
foam and at least one inert gas to form a fire extinguishing agent, and applying the
fire extinguishing agent to the fire.


[019] In yet another aspect, the invention includes a method of
extinguishing a fire including a Class D fire and at least one other, class of fire. The
method may include combining a foam and at least one inert gas to form a fire
extinguishing agent, and applying the fire extinguishing agent to the fire.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[020] Reference will now be made in detail to some possible embodiments
of the invention, examples of which are outlined in this description.
[021] According to one embodiment, a fire extinguishing agent configured
to extinguish a Class D fire and one or more other classes of fires such as, for
example, a Class A fire and/or a Class B fire, may include a foam and one or more
inert gases combined with the foam. For example, the foam may include a foam
marketed by Tyco International Ltd. as "ANSUL TARGET-7®" foam. The use of
other foam agents known to those having skill in the art is contemplated. Some
embodiments may include foam agents that do not include foams based on
fluorocarbon chemistry, such as, for example, AAAF-type foams. The one or more
inert gases may include, for example, helium, neon, argon, krypton, xenon, and/or
radon. For example, the fire extinguishing agent may include a conventional fire
fighting foam gasified with, for example, helium and/or argon, although neon,
krypton, and/or xenon may be included in the fire extinguishing agent.
[022] The foam and the one or more inert gases may be combined via any
method known to those having skill in the art, such as, for example, via combining
in a nozzle of a fire extinguisher agent delivery apparatus and/or combining in a fire
extinguisher agent mixing conduit. The fire extinguishing agent may be applied to a
fire via any methods and/or devices known to those having skill in the art.
According to some embodiments, the foam and the one or more inert gases may be
combined in a ratio corresponding to about 60 gallons of foam-generating solution
per 400 cubic feet of inert gas. Other ratios are contemplated.
[023] Most classes of fires, including Class D fires, require fuel, an
oxidizer, and heat in order to sustain combustion. Unlike most other classes of
fires, however, Class D fires can sustain combustion by liberating necessary
oxidizers from otherwise stable compounds, such as, for example, CO2 and/or
Halon®. Furthermore, unlike many common classes of fires, metal and/or metal


compound fires may burn in oxidizers other than oxygen, such as, for example,
chlorine, fluorine, and/or nitrogen. Class D fires, however, cannot burn in an inert
atmosphere. The family of "true" inert or noble gases includes helium, neon, argon,
krypton, xenon, and radon. Many of the inert gases may be currently thought to be
too rare to be economically viable for use in a fire extinguishing agent. Further,
radon is radioactive. As a result, helium and argon are two inert gases that
currently appear to be desirable for use in a fire extinguishing agent according to
some embodiments.
[024] Attempting to extinguish fires including burning metal(s) and/or metal
compound(s) (e.g., Class D fires) using one or more inert gases alone, however,
may be very difficult. For example, attempting to use an inert gas alone to deprive
such a fire of its oxidizer may not be effective because maintaining coverage may
be difficult since helium is lighter than the surrounding atmosphere and will quickly
float off, and argon is heavier than the surrounding air and will tend settle away
from the area of deployment. Furthermore, the use of conventional foams to
extinguish burning metal(s) and/or metal compound(s) has proven substantially
ineffective, for example, because the water in the foam reacts with the metals to
liberate hydrogen and because of the extreme heat of Class D fires, the fire's
reaction will continue and use the air and/or nitrogen in the foam as an oxidizer,
and the fire will continue to bum.
[025] The combination of foam and inert gas may be effective because
when water in the foam reacts with the metal, a hydroxide radical (not oxygen or
any other oxidizer) is liberated during the reaction. Hydrogen is also liberated, but
in the absence of an oxidizer (no air or nitrogen is used to generate the foam), the
fire is starved out. The foam may serve to trap the inert gas and keep it positioned
where it most effectively acts to extinguish the fire.
[026] Other embodiments of the invention will be apparent to those skilled
in the art from consideration of the specification and practice of the invention
disclosed herein. It is intended that the specification and examples be considered
as exemplary only, with a true scope and spirit of the invention being indicated by
the following claims.


We Claim :
1. A fire extinguishing agent without having an oxidizer, nitrogen, carbon dioxide,
halomethanes. fluorine, chlorine, or sulfur, but comprising:
a foam; and
at least one inert gas combined with the foam;
wherein the at least one inert gas comprises at least one of helium and argon.
2. The fire extinguishing agent as claimed in claim 1, wherein the foam comprises a foam
fire extinguishing agent.
3. A method of extinguishing a fire comprising at least one of a burning metal and a burning
metal compound, the method comprising
the step of applying the fire extinguishing agent, as claimed in claim 1 to the fire.
4. The method as claimed in claim 3, for extinguishing fire, caused by a burning plastic
material and a burning paper.


ABSTRACT

MULTI- CLASS FIRE EXTINGUISHING AGENT
The present invention relates to a fire extinguishing agent comprising: a foam; and at least one inert gas
combined with the foam; wherein the at least one inert gas comprises at least one of helium and argon,
and the fire extinguishing agent does not comprise an oxidizer, nitrogen, carbon dioxide, halomethanes,
fluorine, chlorine, or sulfur. The invention also provides a method of extinguishing a fire comprising
combining a foam and at least one inert gas to form a fire extinguishing agent, and applying the fire
extinguishing agent to the fire, to extinguish the fire.

Documents:

03308-kolnp-2007-abstract.pdf

03308-kolnp-2007-assignment.pdf

03308-kolnp-2007-claims.pdf

03308-kolnp-2007-correspondence others.pdf

03308-kolnp-2007-description complete.pdf

03308-kolnp-2007-form 1.pdf

03308-kolnp-2007-form 3.pdf

03308-kolnp-2007-form 5.pdf

03308-kolnp-2007-international publication.pdf

03308-kolnp-2007-international search report.pdf

03308-kolnp-2007-pct priority document notification.pdf

03308-kolnp-2007-pct request form.pdf

3308-KOLNP-2007-(01-01-2013)-CORRESPONDENCE.pdf

3308-KOLNP-2007-(12-06-2012)-ABSTRACT.pdf

3308-KOLNP-2007-(12-06-2012)-AMANDED CLAIMS.pdf

3308-KOLNP-2007-(12-06-2012)-AMANDED PAGES OF SPECIFICATION.pdf

3308-KOLNP-2007-(12-06-2012)-CORRESPONDENCE.pdf

3308-KOLNP-2007-(12-06-2012)-DESCRIPTION (COMPLETE).pdf

3308-KOLNP-2007-(12-06-2012)-FORM-1.pdf

3308-KOLNP-2007-(12-06-2012)-FORM-2.pdf

3308-KOLNP-2007-(12-06-2012)-FORM-3.pdf

3308-KOLNP-2007-(12-06-2012)-OTHERS.pdf

3308-KOLNP-2007-(12-06-2012)-PETITION UNDER RULE 137.pdf

3308-KOLNP-2007-ASSIGNMENT.pdf

3308-KOLNP-2007-CORRESPONDENCE OTHERS 1.1.pdf

3308-KOLNP-2007-CORRESPONDENCE.pdf

3308-KOLNP-2007-EXAMINATION REPORT.pdf

3308-KOLNP-2007-FORM 18-1.1.pdf

3308-kolnp-2007-form 18.pdf

3308-KOLNP-2007-FORM 3-1.1.pdf

3308-KOLNP-2007-FORM 5.pdf

3308-KOLNP-2007-GPA.pdf

3308-KOLNP-2007-GRANTED-ABSTRACT.pdf

3308-KOLNP-2007-GRANTED-CLAIMS.pdf

3308-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

3308-KOLNP-2007-GRANTED-FORM 1.pdf

3308-KOLNP-2007-GRANTED-FORM 2.pdf

3308-KOLNP-2007-GRANTED-SPECIFICATION.pdf

3308-KOLNP-2007-OTHERS.pdf

3308-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf


Patent Number 254956
Indian Patent Application Number 3308/KOLNP/2007
PG Journal Number 02/2013
Publication Date 11-Jan-2013
Grant Date 08-Jan-2013
Date of Filing 06-Sep-2007
Name of Patentee FEDEX CORPORATION
Applicant Address 3620 HACK CROSS ROAD, BUILDING B, THIRD FLOOR, MEMPHIS, TENNESSEE
Inventors:
# Inventor's Name Inventor's Address
1 POPP JAMES B. 7973 GERMANTOWN ROAD, OLIVE BRANCH, MISSISSIPPI 38654
PCT International Classification Number A62C 2/00,A62C 3/00
PCT International Application Number PCT/US2006/006481
PCT International Filing date 2006-02-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/656,436 2005-02-25 U.S.A.