CA2095640C - Fire extinguishing composition and process - Google Patents
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- CA2095640C CA2095640C CA002095640A CA2095640A CA2095640C CA 2095640 C CA2095640 C CA 2095640C CA 002095640 A CA002095640 A CA 002095640A CA 2095640 A CA2095640 A CA 2095640A CA 2095640 C CA2095640 C CA 2095640C
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- pentafluoropropane
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D1/00—Fire-extinguishing compositions; Use of chemical substances in extinguishing fires
- A62D1/0028—Liquid extinguishing substances
- A62D1/0057—Polyhaloalkanes
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Abstract
A process for extinguishing, preventing and controlling fires using a composition containing at least one fluoro-substituted ethane elected from the group of CF3-CHF2; CHF2-CHF2, CF3-CH2F, CF3-CHFCl, CF2Cl-CHF2, CF3-CHCl2, CF2Cl-CHFCl, CFCl2-CHF2, and CHFCl-CNFCl is disclosed. The ethane can be used in open or enclosed areas with little or no effect on the ozone in the stratosphere and with little effect on the global warming process.
Description
V'"°.92/08520 ~ ~ ~ ~ ~ ~~ ~ PCT/1,J~90/06692 1 a Fire Extinguishing Composition and Process Field of Invention This invention relates to compositions for use in preventing and extinguishing fires based on the combustion of combustible materials. More particularly, it relates to such compositions that are highly effective and "environmentally safe".
to Specifically, the compositions of this invention have little or no effect on the ozone layer depletion process: and make no or very little contribution to the global warming process known as the '°greenhouse effect''. Although these compositions have minimal effect in these areas, they are extremely effective in preventing and extinguishing fires, particularly fires in enclosed spaces.
Backaround of the Invention and Prior Art In preventing or extinguishing fires, two important elements must be considered for success (1) separating the combustibles from air: and (2) avoiding or reducing the temperature necessary for combustion to proceed. Thus, one can smother small fires with blankets or with foams to cover the burning surfaces to isolate the combustibles from the oxygen in the air.
Tn the austr~mary process of pouring water on the burning surfaces to put out the fire, the main element i.s reducing temperature to a point there combustion cannot proceed. Obviously, some smothering or separation of combustibles from air also occurs in the water situat~.on.
The particular process used to extinguish fires depends upon several items, e.g. the'location of the dire, the combustibles involved, the size of the - .2 -fire, etc. In fixed enclosures such as computer rooms, storage vaults, rare book library rooms, petroleum pipeline pumping stations and the like, halogenated hydrocarbon fire extinguishing agents are currently preferred. These halogenated hydrocarbon fire extinguishing agents are not only effective for such fires, but also cause little, if any, damage to the room or its contents. This contrasts to the well-known "water damage"' that can sometimes exceed the fire damage when the customary water pouring process is used.
The halogenated hydrocarbon fire extinguishing agents that are currently most popular are the bromine-containing halocarbons, e.g.
bromotrifluoromethane (CF3Hr, Halon 1301) and bromochlorodifluoromethane (CF2CIBr, Halon TM1211). It is believed that these bromine-containing fire extinguishing agents are highly effective in extinguishing fires in progress because, at the elevated temperatures involved in the combustion, these compounds decompose to form products containing bromine atoms which effectively interfere with the self-sustaining free radical combustion process and, thereby, extinguish the fire. These bromine-containing halocarbons may be dispensed from portable equipment or from an automatic room flooding system activated by a fire detector.
In many situations, enclosed spaces are involved. Thus, fires may occur in rooms, vaults, enclosed machines, ovens, containers, storage tanks, bins and like areas.
The use of an effective amount of fire extinguishing agent in an enclosed space involves two situations. In one situation, the fire extinguishing agent is introduced into the enclosed space to '"'7 92/08520 ~ ~ ~ ~ 6 ~' a PCTlUS90l06692 - g -extinguish an existing fire; the second situation is to provide an ever-present atmosphere containing the fire "extinguishing" or, more accura~ly~prevention~agent in such an amount that fire cannat be initiated nor sustained. Thus, in U.S. Patent 3,844,354, Larsen suggests the use of chloropentafluoroethane (CF3-CF2C1) in a total flooding system (TFS) to extinguish fires in a fixed enclosure, the chloropentafluoroethane being introduced into the fixed enclosure to maintain its concentration at less than 15%. On the other hand, in U.S. Patent 3,715,438, Huggett discloses creating an atmosphere in a fixed enclosure which does not sustain combustion. Huggett provides an atmosphere consisting essentially of air, a perfluorocarbon selected from carbon tetrafluoride, hexafluoroethane, octafluoropropane and mixtures thereof.
It has also been known that bromine--containing halocarbons such as Halon 1211 can be used to provide an atmosphere that will not support combustion. However, the high cost due to bromine content and the toxicity to humans i.e. cardiac sensitization at relatively law levels (e. g. Halon 1211 cannot be used above 1-2 ~) make the bromine-containing materials unattractive for long term use.
In recent years, even more serious objections to the use of brominated halocarbon fire extinguishants has arisen. The depletion of the stratospheric atone layer, and particularly the role of chlorofluorocarbons (CFO's) have led to gxsat interest in developing alternative refrigerants, solvents, blowing agents, etc. It is now believed that bromine-containing halocarbons such as glalon 1301 and Halon 1211 are at least as active as chlorofluorocarbons in the ozone layer depletion process.
~~~~640 !WO 92/08520 PC1'/US90/06692--q, _ While perfluorocarbons such as those suggested by Huggett, cited above, are believed not to have as much effect upon the ozone depletion process as chlorofluorocarbons, their extraordinarily high stability makes them suspect in another environmental area, that of "greenhouse effect'°. This effect is caused by accumulation of gases that provide a shield against heat transfer and results in the undesirable warming of the earth°s surface.
There is, therefore, a need for an effective fire extinguishing composition and process which contributes little or nothing to the stratospheric ozone depletion process or to the °°greenhouse effect°°.
It is an object of the present invention to provide such a fire extinguishing composition; and to provide a process for preventing and controlling fire in a fixed enclosure by introducing in~o.sa~.d fixed enclosure, an effective amount of the composition.
summary of Invention The present invention is based on the finding that an effective amount of a composition comprising at least one partial3y fluoro-substituted ethane selected from the group of pent~afluoroethane (CF3-CHF2), also known as HFC-1.25, the tetrafluoroethanes (CHF2-CHF2 and CF3-CH2F), also known as HFC-13~ and HFC-7.34a, the chlorotetrafluoroethanes (CF3-CFHCI and CF2C1-CF2H), alSO known aS HCFC-124 and HCFC-124a, the dichlorotrifluoroethanes (CF3-CHC12 and CF2C1-CHFC1), also known as HCFC-123 and. HCFC-123x, and the dichlarodifluoroethanes (CHFC1-CHFC1 and CC12F-CH2F), also known as HCFC-7.32 and HCFC-132c will prevent and/or extinguish fire based on the combustion of combustible materials, particularly in an enclosed ~~ ~ PC1'/U590/06692 ~'"~ 92/08520 space, without adversely affecting the atmosphere from the standpoint of ozone depletion or "greenhouse effect°'. The preferred group comprises CF3-CHF2, CF3-CH2F and CF3-CHC12. ..
The partially fluoro-substituted ethanes above may be used in conjunction with as little as 1%
of at least one halogenated hydrocarbon selected from the group of difluoromethane (HFC-32), chlorodifluoromethane (HCFC-22), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1-chloro-1,1,2,2-tetrafluoroethane (HCFC-124a), pen~afluaroethane (HFC-125), 1,3,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca), 1,3~-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb), 2,2-dichloro-1,1,1,3,3-pentafluoropropane (HCFC-225aa), 2,3-dichloro-1,1,1,3,3-pentafluoropropane (HCFC-225da), 2~ Z,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,2,3,3-hexafluoropropane (HFC-23cea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,2,1,2,2,3-hexafluoropropane (HFC-236cb), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 1,2-dichloro-1,2-difluoroethane (HCFC-132), 1,1-dichloro-1,2-difluoroethane (HCFC-132c), 3-chloro-1,1,2,2,3-pentafluoropropane (HCFC-235ca), 3-chloro-1,1,1,2,2-pentafluoropropane (HCFC-235cb), 1-chloro-1,1,2,2,3-pentafluoropropane (HCFC-235cc), 3-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235fa), 3-chloro-1,1,1,2,2,3--hexafluoropropane (HCFC-226ca), 1-chloro-1,1,2,2,3,3-hexafluoropropane (HCFC-226cb), 2-chloro-1,1,1,3,3,3-hexaflu~ropropane (HCFC-226da), 3-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC-226ea), and 2-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC-226ba).
In one aspect of the present invention, there is provided a process for preventing a fire in an enclosed air-containing area which contains combustible materials of the non-self-sustaining type, the process comprising the steps of introducing into the air in said enclosed area an amount of at least one fluoro-substituted ethane selected from the group of CF3-CHFz, CHFZ-CHFz, CFj-CHZF, CF3-CHFC1 and CF2C1-CFzH sufficient to impart a heat capacity per mol of total oxygen that will prevent combustion of the combustible materials in said enclosed area.
In a second aspect of the present invention, there is provided a process for preventing a fire which comprises introducing a volume of at least one fluoro-substituted ethane selected from the group of CF3-CHF2, CHFZ-CHF2, CF3-CHzF, CF3-CHFC1 and CFzCl-CFzH sufficient to provide an fire-preventing concentration in an enclosed area, and maintaining said concentration at a value of less than 80 volume percent.
In a further aspect of the present invention, a composition is provided for preventing a fire in an enclosed area comprising at least 8 volume percent of at least one fluoro-substituted ethane selected from the group of CF3-CHFz, CHFz-CHFz, CF3-CHZF, CF3-CHFC1 and CFZC1-CF2H.
And in yet a further aspect of the present invention, there is provided a fire-preventing composition comprising at least one of fluoro-substituted ethane selected from the group of CF3-CHF2, CHFZ-CHF2, CF3-CHzF, CF3-CHFC1 and CF2C1-CFZH, CF3-CHC12, CF2C1-CHFC1, CFC12-CHzF and CHFCl-CHFCl.
- 6a -Preferred Embodiments The partially fluoro-substituted ethanes, when added in adequate amounts to the air in a confined space, eliminates the combustion-sustaining properties of the air and suppresses the combustion of flammable materials, such as paper, cloth, wood, flammable liquids, and plastic items, which may be present in the enclosed compartment.
These fluoroethanes are extremely stable and chemically inert. They do not decompose at temperatures as high as 350'C to produce corrosive or toxic products and cannot be ignited even in pure oxygen so that they continue to be effective as a flame suppressant at the ignition temperatures of the combustible items present in the compartment.
The particularly preferred fluoroethanes HFC-125, HFC-134, and HFC-134a, as well as HCFC-124 are additionally advantageous because of their low boiling points, i.e. boiling points at normal atmospheric pressure of less than -12'C. Thus; at any low environmental temperature likely to be encountered, these gases will not liquefy and will not, thereby, diminish the fire preventive properties of the modified air. In fact, any material having such a low boiling point would be suitable as a refrigerant.
The fluoroethane HFC-125 is also characterized by an extremely low boiling point and high vapor pressure, i.e. above 164 psig at 21'C. This permits HFC-125 to act as its own propellant in "'hand-held"' fire extinguishers. Pentafluoroethane (HFC-125) may also be used with other materials such as a"~ 92108520 ~ ~ ~ PC°i'1U590/06692 those disclosed on pages 5 and E> of this specification to act as the propellant and co-extinguishant for these materials of lower vapor pressure. Alternatively, these other materials of lower~vapor pressure may be propelled from a portable fire extinguisher by the usual propellants, i.e. nitrogen or carbon dioxide.
Their relatively low toxicity and their short atmospheric lifetime (with little effect on the global warming potential) compared to the perfluoroalkanes (with lifetimes of over 500 years) make these fluoroethanes ideal for this fire-extinguisher use.
To eliminate the combustion-sustaining properties of the air in the confined space situation, the gas or gases should be added in an amount which will impart to the modified air a heat capacity per mole of total oxygen present sufficient to suppress or prevent combustion of the flammable, non-self-sustaining materials present in the enclosed environment.
The minimum heat capacity required to suppress combustion varies with the combustibility of the particular flammable materials present in the confined space. It is well known that the combustibility of materials, namely their capability for igniting and maintaining sustained combustion under a given set of environmental conditions, varies according to chemical c~mposition and certain physical properties, such as surface area relative to volume, heat capacity, porosity, and the like. Thus, thin, 30porous paper such as tissue paper is considerably more combustible than a bloc)c of wood.
In general, a heat capacity of about 40 cal./'C and constant pressure per mole of oxygen is more than adequate to prevent or suppress the combustion of materials of relatively moderate WO 92/08520 2 ~ (~ C~ ~ ~ ~ . 1PCT/US90/06692 --.
_ g _ combustibility, such as wood and plastics. More combustible materials, such as paper, cloth, and some 'volatile flammable liquids, generally require that the fluoroethane be added in an amount sufficient to impart a higher heat capacity. It is also desirable to provide an extra margin of safety by imparting a heat capacity in excess of minimum requirements for the particular flammable materials. A minimum heat capacity of 45 cal./°C per mole of axygen is generally adequate for moderately combustible materials and a minimum of about 50 cal./°C per mole of oxygen for highly flammable materials. More can be added if desired but, in general, an amount imparting a heat capacity higher than about 55 cal./°C per mole of total oxygen adds substantially to the cost without any substantial further increase in the fire safety factor.
Heat capacity per mole of total oxygen can be determined by the formula:
Cp* = (Cp)o + ~Px (C )Z
2 po p wherein:
Cp* = total heat capacity per mole of oxygen at z5 constant pressure;
Po = partial pressure of oxygens P~ = partial pressure of other gas;
(Cp)z = heat capacity of ~~ther gas at constant pressure.
The boiling points of the fluoroethanes used in this invention and the mole percents required to impart to air heat capacities (Cp) of 40 and 50 cal./°C
at a temperature of 25°C and constant pressure while '"'192/08520 PC d'/'US90/06692 g -maintaining a 20% and 16 % oxygen content are tabulated below:
20 % 0~~ 16 Boiling C =50 C
=40' C ~50 p p p point, vol vol VO1 FC 'C. percent percent percent 125 -48.5 6.5 19.5 ~ 6.5 134 -19.7 8.5 25.0 8.5 134x -26.5 7.0 20.5 7.0 124 -12.0 6.5 19.0 6.5 124a -10.2 ~ 6.5 19.0 6.5 123 27.9 6.9 17.0 6.0 123a 30.0 6.0 17:5 6.0 132 59.0 7.0 20.5 7.0 132c 48.4 6.5 19.0 6.5 Introduction of the appropriate gaseous fluoroethanes is easily accomplished by metering apprapriate quantities of the gas or gases into the enc~.osed air-containing co~apartment.
The air in the compartment can be treated at any time that it appears desirable. The modified air can be used continuously if a threat of fire is constantly present or if the particular environ~aent is, such that the, fire hazard must be kept at an absolute minimum: or the modified air can be used as an emergency measure if a threat of fire develops.
The invention w~:l.l be more clearly understood by referring to the examples which follow. The unexpected effects of the fluoroethane compositions, in suppressing and combatting fire, as well as its computability with the ozone layer and its relatively low greenhouse effect, when compared to other fire- .
combatting gases, particularly the perfluoroalkanes and Halon 1211, are shown in the examples.
iy0 92/0520 ~ ;; ;.j ~.~ ~.. ~ ,, PC!'/U590/06692 ..~.
_ ~0 Example 1 - Fire Extine~uishin~ Concentrations The fire extinguishing concentration of the fluoroethane compositions compared to several controls, was determined by the ICZ Cup Eurner method. This method is described in "Measurement of Flame-Extinguishing Concentrationsn F~. Hirst and K.
Booth, Fire Technology, Vol. 13(4): 296-315 (1977).
Specifically, an air stream is passed at 40 l0 liters/minute through an outer chimney (8.5 cm. I. D.
by 53 cm. tall) from a glass bead distributor at its base. A fuel cup burner (3.1 cm. O.D. and 2.15 cm.
I.D.) is positioned within the chimney at 30.5 cm.
below the top edge of the chimney. The fire ext~.nguishing agent is added to the air stream prior to its entry into the glass bead distributor while the air flow rate is maintained at 40 liters/minute for all tests. The air and agent flow rates are measured using calibrated rotameters.
Each test is conducted by adjusting the fuel level iri the reservoir to bring the liquid fuel level in the cup burner just even-;with the ground glass lip on the burner cup. With tha air flow rate maintained at 40 liters/minute, the fuel in the cup burner is ignited. 'The $ire extinguishing agent is added in measured increments until the flame is extinguished.
The fire extinguishing concentration is determined from the following equation:
Extinguishing concentration ~ F1 x 100 F
where F1 = Agent flow rate Fa ~ Air flow rate A
urn 9aioss2o ~crms~od~a~ ~. r 209~~~0 - 17. -Two different fuels are used, heptane and methanol; and the average of several values of agent flow rate at extinguishment is used for the following table.
Table 1 Extinguishing Concentrations of Certain Fluoroethane Comlaositions Compared to Other Agents Agent Fuel Flow Rate Heptane Methanol-Extinguishing Air Agent Conc.
(vol. (vol. (1/min) (1/min) %) %) Fe H~ Meth.
HCFC-123 7.1 10.6 40.1 3.06 4.75 HCFG-123a 7.7 10.1 40.1 3.37 5.11 HCFC-124 8.0 11.9 40.1 3.49 5.45 HFC-125 10.1 13.0 40.1 4.51 5.99 HFC-134a 11.5 15.7 40.1 5.22 7.48 CF4, r 20.5 23.5 40.1 10.31 12.34 C2F6 8.7 11.5 40.1 3.81 .5.22 H-1301* 4.2 8.6 40.1 1.77 3.77 H-1211** 6.2 8.5 40.1 2.64 3.72 .
CHF2C1 13.6 22.5 40.1 6.31 11.64 * CF3~r ** CF2ClBr WO 92/0520 _ ~ ~ ~ a ~ ~ ~ P~LT/'U590106G92~..-.,, - 1~ -Example 2 Cardiac Sensitivity The cardiac sensitivity or toxicity of the fluoroethanes, compared to several controls, was determined using the methods described in "Relative ' Effects of Haloforms and Epinephrine on Cardiac Automaticity~' R. M. Hopkins and J. C. Krantz, Jr., Anesthesia and Analgesia, vol. 47 no. 1 (1968) and "Cardiac Arrhythmias and Aerosol °Sniffing'°' C. F.
Reinhardt et al. Arch. Environ. Health vol. 22 (February 1971).
Specifically, the cardiac sensitivity is measured using unanesthesized, healthy dogs using the general protocal set forth in the Reinhardt et al article. First, far a limited period, the dog is subjected to air flow through a semiclosed inhalation system connected to a cylindrical face mask on the dog.
Then, epinephrine hydrochloride (adrenaline), diluted with saline solution, is administered intravenously and the electrocardiograph is recorded. Then air containing various concentrations of the agent being tested is administered followed by a second injectian of epinephrine. The concentrations of agent necessary to produce a disturbance in the normal conduction of an electrical~impulse through the heart as characterized by a serious cardiac arrhythmia, are shown in the following table.
v"~ 92/08520 ~ ~ ~ ~ ~ ~ ~ PCT/~.1~9'~~/0~692 Table 2 Threshhold Cardiac Sensitivity agent (vol. % in air) HFC-134a 7.5 H-1301* 7.5 CHF2C1 5.0 HCFC-124 2.5 HCFC-123 1.9 Ii-1211** 1 to 2 * CF3Br ** CF2CIBr ~Ca 92/08520 PGT/US90/06692..-., ~0~~6~.U
Example 3 The ozone depletion potential (ODP) of the fluoroethanes and various blends thereof, compared to various controls, was calculated using the method described in "'The Relative Efficiency of a Number of Halocarbon for Destroying Stratospheric Ozone" D. J.
Wuebles, Lawrence Livermore Laboratory report UCTD-18924, (January 1981) and "Chlorocarbon Emission Scenarios: Potential Impact on Stratospheric Ozone" D.
J. Wuebles, Journal Geophysics Research, 88, 1433-1443 (1983).
Basically, the ODP is the ratio of the calculated ozone depletion in the stratosphere resulting from the emission of a particular agent compared to the ODP resulting from the same rate of emission of FC-11 (CFC13) which is set at.lØ Ozone depletion is believed to be due to the migration of compounds containing chlorine or bromine through the troposphere into the stratosphere where these compounds are photolyzed by UV radiation into chlorine or bromine atoms. These atoms twill destroy the ozone (03) molecules in a cyclical reaction where molecular oxygen (02) and [C10] or [BrO] radicals are formed, those radicals reacting with oxygen atoms formed by UV
radiation of 02 to reform chlorine or bromine atoms and oxygen molecules, and the reformed chlorine or bromine atoms then destroying additional ozone, eta., until the radicals are finally scavenged from the stratosphere. 7Ct is estimated that one chlorine atom will destroy 10,000 ozone molecules and one bromine atom will destroy 100,000 ozone molecules.
The ozone depletion potential is also discussed in "Ultraviolet Absorption Cross-Sections of Several Brominated Methanes and Ethanes°° L. T. Molina, l~l. J. Molina and k'. S, Rowland" J. Phys. Chem. 86, "'~ 92/08520 ~ PC I /g1S90/06692 _ y 2672-2676 (1982); in Hivens et al. U.S. Patent 4,810,403; and in "Scientific Assessment of Stratospheric Ozone: 1989n U.N. Environment Programme (21 August 198J).
Tn the following table, the ozone depletion potentials are presented for the fluoroethanes used in this invention and various.controls.
Table 3 2.0 Ozone Depletion Agent Potenta.al HCFC123 0.013 HCFC1.24 0 . 013 HFC134a 0 CF4 . 0 CHF2C1 0.05 CF3CF2C1 0.4 W~ 92/08520 . F~CT/~US90/06692 ..-..
209~6~0 Example 4 The glabal warming potentials (GWP) of the fluoroethane and various blends thereof, compared to several controls, was determined using the method described in "Scientific Assessment of Stratospheric Ozane: 1989" sponsored by the U.N. Environment Programme.
The GRIP, also ltnown as the "greenhouse effect" is a phenomenon that occurs in the troposphere.
It is calculated using a model that incorporates parameters based on the agent's atmospheric lifetime and its infra-red cross-section or its infra-red absorption strength per mole as measured with an infra-red spectrophotometer.
The general definition is:
Calculated IR forcing GWP = due to agent Emission rate (steady state) of agent divided by the same ratio of parameters for CFC13.
In the following table, the GWP's are presented for the fluoroethanes and the controls.
Table 4 Global Warming Potential HFC-134a 0.220 HFC-125 0.420 HCFC-124 0.080 HCFC-1,2 3 0 . 015 CF4 greater than 5 C2F6 greater than 8 CHF2C1 0.29 CFC13 1.0 CF3CF2C1 8.2
to Specifically, the compositions of this invention have little or no effect on the ozone layer depletion process: and make no or very little contribution to the global warming process known as the '°greenhouse effect''. Although these compositions have minimal effect in these areas, they are extremely effective in preventing and extinguishing fires, particularly fires in enclosed spaces.
Backaround of the Invention and Prior Art In preventing or extinguishing fires, two important elements must be considered for success (1) separating the combustibles from air: and (2) avoiding or reducing the temperature necessary for combustion to proceed. Thus, one can smother small fires with blankets or with foams to cover the burning surfaces to isolate the combustibles from the oxygen in the air.
Tn the austr~mary process of pouring water on the burning surfaces to put out the fire, the main element i.s reducing temperature to a point there combustion cannot proceed. Obviously, some smothering or separation of combustibles from air also occurs in the water situat~.on.
The particular process used to extinguish fires depends upon several items, e.g. the'location of the dire, the combustibles involved, the size of the - .2 -fire, etc. In fixed enclosures such as computer rooms, storage vaults, rare book library rooms, petroleum pipeline pumping stations and the like, halogenated hydrocarbon fire extinguishing agents are currently preferred. These halogenated hydrocarbon fire extinguishing agents are not only effective for such fires, but also cause little, if any, damage to the room or its contents. This contrasts to the well-known "water damage"' that can sometimes exceed the fire damage when the customary water pouring process is used.
The halogenated hydrocarbon fire extinguishing agents that are currently most popular are the bromine-containing halocarbons, e.g.
bromotrifluoromethane (CF3Hr, Halon 1301) and bromochlorodifluoromethane (CF2CIBr, Halon TM1211). It is believed that these bromine-containing fire extinguishing agents are highly effective in extinguishing fires in progress because, at the elevated temperatures involved in the combustion, these compounds decompose to form products containing bromine atoms which effectively interfere with the self-sustaining free radical combustion process and, thereby, extinguish the fire. These bromine-containing halocarbons may be dispensed from portable equipment or from an automatic room flooding system activated by a fire detector.
In many situations, enclosed spaces are involved. Thus, fires may occur in rooms, vaults, enclosed machines, ovens, containers, storage tanks, bins and like areas.
The use of an effective amount of fire extinguishing agent in an enclosed space involves two situations. In one situation, the fire extinguishing agent is introduced into the enclosed space to '"'7 92/08520 ~ ~ ~ ~ 6 ~' a PCTlUS90l06692 - g -extinguish an existing fire; the second situation is to provide an ever-present atmosphere containing the fire "extinguishing" or, more accura~ly~prevention~agent in such an amount that fire cannat be initiated nor sustained. Thus, in U.S. Patent 3,844,354, Larsen suggests the use of chloropentafluoroethane (CF3-CF2C1) in a total flooding system (TFS) to extinguish fires in a fixed enclosure, the chloropentafluoroethane being introduced into the fixed enclosure to maintain its concentration at less than 15%. On the other hand, in U.S. Patent 3,715,438, Huggett discloses creating an atmosphere in a fixed enclosure which does not sustain combustion. Huggett provides an atmosphere consisting essentially of air, a perfluorocarbon selected from carbon tetrafluoride, hexafluoroethane, octafluoropropane and mixtures thereof.
It has also been known that bromine--containing halocarbons such as Halon 1211 can be used to provide an atmosphere that will not support combustion. However, the high cost due to bromine content and the toxicity to humans i.e. cardiac sensitization at relatively law levels (e. g. Halon 1211 cannot be used above 1-2 ~) make the bromine-containing materials unattractive for long term use.
In recent years, even more serious objections to the use of brominated halocarbon fire extinguishants has arisen. The depletion of the stratospheric atone layer, and particularly the role of chlorofluorocarbons (CFO's) have led to gxsat interest in developing alternative refrigerants, solvents, blowing agents, etc. It is now believed that bromine-containing halocarbons such as glalon 1301 and Halon 1211 are at least as active as chlorofluorocarbons in the ozone layer depletion process.
~~~~640 !WO 92/08520 PC1'/US90/06692--q, _ While perfluorocarbons such as those suggested by Huggett, cited above, are believed not to have as much effect upon the ozone depletion process as chlorofluorocarbons, their extraordinarily high stability makes them suspect in another environmental area, that of "greenhouse effect'°. This effect is caused by accumulation of gases that provide a shield against heat transfer and results in the undesirable warming of the earth°s surface.
There is, therefore, a need for an effective fire extinguishing composition and process which contributes little or nothing to the stratospheric ozone depletion process or to the °°greenhouse effect°°.
It is an object of the present invention to provide such a fire extinguishing composition; and to provide a process for preventing and controlling fire in a fixed enclosure by introducing in~o.sa~.d fixed enclosure, an effective amount of the composition.
summary of Invention The present invention is based on the finding that an effective amount of a composition comprising at least one partial3y fluoro-substituted ethane selected from the group of pent~afluoroethane (CF3-CHF2), also known as HFC-1.25, the tetrafluoroethanes (CHF2-CHF2 and CF3-CH2F), also known as HFC-13~ and HFC-7.34a, the chlorotetrafluoroethanes (CF3-CFHCI and CF2C1-CF2H), alSO known aS HCFC-124 and HCFC-124a, the dichlorotrifluoroethanes (CF3-CHC12 and CF2C1-CHFC1), also known as HCFC-123 and. HCFC-123x, and the dichlarodifluoroethanes (CHFC1-CHFC1 and CC12F-CH2F), also known as HCFC-7.32 and HCFC-132c will prevent and/or extinguish fire based on the combustion of combustible materials, particularly in an enclosed ~~ ~ PC1'/U590/06692 ~'"~ 92/08520 space, without adversely affecting the atmosphere from the standpoint of ozone depletion or "greenhouse effect°'. The preferred group comprises CF3-CHF2, CF3-CH2F and CF3-CHC12. ..
The partially fluoro-substituted ethanes above may be used in conjunction with as little as 1%
of at least one halogenated hydrocarbon selected from the group of difluoromethane (HFC-32), chlorodifluoromethane (HCFC-22), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1-chloro-1,1,2,2-tetrafluoroethane (HCFC-124a), pen~afluaroethane (HFC-125), 1,3,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca), 1,3~-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb), 2,2-dichloro-1,1,1,3,3-pentafluoropropane (HCFC-225aa), 2,3-dichloro-1,1,1,3,3-pentafluoropropane (HCFC-225da), 2~ Z,1,1,2,2,3,3-heptafluoropropane (HFC-227ca), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,2,3,3-hexafluoropropane (HFC-23cea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,2,1,2,2,3-hexafluoropropane (HFC-236cb), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 1,2-dichloro-1,2-difluoroethane (HCFC-132), 1,1-dichloro-1,2-difluoroethane (HCFC-132c), 3-chloro-1,1,2,2,3-pentafluoropropane (HCFC-235ca), 3-chloro-1,1,1,2,2-pentafluoropropane (HCFC-235cb), 1-chloro-1,1,2,2,3-pentafluoropropane (HCFC-235cc), 3-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235fa), 3-chloro-1,1,1,2,2,3--hexafluoropropane (HCFC-226ca), 1-chloro-1,1,2,2,3,3-hexafluoropropane (HCFC-226cb), 2-chloro-1,1,1,3,3,3-hexaflu~ropropane (HCFC-226da), 3-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC-226ea), and 2-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC-226ba).
In one aspect of the present invention, there is provided a process for preventing a fire in an enclosed air-containing area which contains combustible materials of the non-self-sustaining type, the process comprising the steps of introducing into the air in said enclosed area an amount of at least one fluoro-substituted ethane selected from the group of CF3-CHFz, CHFZ-CHFz, CFj-CHZF, CF3-CHFC1 and CF2C1-CFzH sufficient to impart a heat capacity per mol of total oxygen that will prevent combustion of the combustible materials in said enclosed area.
In a second aspect of the present invention, there is provided a process for preventing a fire which comprises introducing a volume of at least one fluoro-substituted ethane selected from the group of CF3-CHF2, CHFZ-CHF2, CF3-CHzF, CF3-CHFC1 and CFzCl-CFzH sufficient to provide an fire-preventing concentration in an enclosed area, and maintaining said concentration at a value of less than 80 volume percent.
In a further aspect of the present invention, a composition is provided for preventing a fire in an enclosed area comprising at least 8 volume percent of at least one fluoro-substituted ethane selected from the group of CF3-CHFz, CHFz-CHFz, CF3-CHZF, CF3-CHFC1 and CFZC1-CF2H.
And in yet a further aspect of the present invention, there is provided a fire-preventing composition comprising at least one of fluoro-substituted ethane selected from the group of CF3-CHF2, CHFZ-CHF2, CF3-CHzF, CF3-CHFC1 and CF2C1-CFZH, CF3-CHC12, CF2C1-CHFC1, CFC12-CHzF and CHFCl-CHFCl.
- 6a -Preferred Embodiments The partially fluoro-substituted ethanes, when added in adequate amounts to the air in a confined space, eliminates the combustion-sustaining properties of the air and suppresses the combustion of flammable materials, such as paper, cloth, wood, flammable liquids, and plastic items, which may be present in the enclosed compartment.
These fluoroethanes are extremely stable and chemically inert. They do not decompose at temperatures as high as 350'C to produce corrosive or toxic products and cannot be ignited even in pure oxygen so that they continue to be effective as a flame suppressant at the ignition temperatures of the combustible items present in the compartment.
The particularly preferred fluoroethanes HFC-125, HFC-134, and HFC-134a, as well as HCFC-124 are additionally advantageous because of their low boiling points, i.e. boiling points at normal atmospheric pressure of less than -12'C. Thus; at any low environmental temperature likely to be encountered, these gases will not liquefy and will not, thereby, diminish the fire preventive properties of the modified air. In fact, any material having such a low boiling point would be suitable as a refrigerant.
The fluoroethane HFC-125 is also characterized by an extremely low boiling point and high vapor pressure, i.e. above 164 psig at 21'C. This permits HFC-125 to act as its own propellant in "'hand-held"' fire extinguishers. Pentafluoroethane (HFC-125) may also be used with other materials such as a"~ 92108520 ~ ~ ~ PC°i'1U590/06692 those disclosed on pages 5 and E> of this specification to act as the propellant and co-extinguishant for these materials of lower vapor pressure. Alternatively, these other materials of lower~vapor pressure may be propelled from a portable fire extinguisher by the usual propellants, i.e. nitrogen or carbon dioxide.
Their relatively low toxicity and their short atmospheric lifetime (with little effect on the global warming potential) compared to the perfluoroalkanes (with lifetimes of over 500 years) make these fluoroethanes ideal for this fire-extinguisher use.
To eliminate the combustion-sustaining properties of the air in the confined space situation, the gas or gases should be added in an amount which will impart to the modified air a heat capacity per mole of total oxygen present sufficient to suppress or prevent combustion of the flammable, non-self-sustaining materials present in the enclosed environment.
The minimum heat capacity required to suppress combustion varies with the combustibility of the particular flammable materials present in the confined space. It is well known that the combustibility of materials, namely their capability for igniting and maintaining sustained combustion under a given set of environmental conditions, varies according to chemical c~mposition and certain physical properties, such as surface area relative to volume, heat capacity, porosity, and the like. Thus, thin, 30porous paper such as tissue paper is considerably more combustible than a bloc)c of wood.
In general, a heat capacity of about 40 cal./'C and constant pressure per mole of oxygen is more than adequate to prevent or suppress the combustion of materials of relatively moderate WO 92/08520 2 ~ (~ C~ ~ ~ ~ . 1PCT/US90/06692 --.
_ g _ combustibility, such as wood and plastics. More combustible materials, such as paper, cloth, and some 'volatile flammable liquids, generally require that the fluoroethane be added in an amount sufficient to impart a higher heat capacity. It is also desirable to provide an extra margin of safety by imparting a heat capacity in excess of minimum requirements for the particular flammable materials. A minimum heat capacity of 45 cal./°C per mole of axygen is generally adequate for moderately combustible materials and a minimum of about 50 cal./°C per mole of oxygen for highly flammable materials. More can be added if desired but, in general, an amount imparting a heat capacity higher than about 55 cal./°C per mole of total oxygen adds substantially to the cost without any substantial further increase in the fire safety factor.
Heat capacity per mole of total oxygen can be determined by the formula:
Cp* = (Cp)o + ~Px (C )Z
2 po p wherein:
Cp* = total heat capacity per mole of oxygen at z5 constant pressure;
Po = partial pressure of oxygens P~ = partial pressure of other gas;
(Cp)z = heat capacity of ~~ther gas at constant pressure.
The boiling points of the fluoroethanes used in this invention and the mole percents required to impart to air heat capacities (Cp) of 40 and 50 cal./°C
at a temperature of 25°C and constant pressure while '"'192/08520 PC d'/'US90/06692 g -maintaining a 20% and 16 % oxygen content are tabulated below:
20 % 0~~ 16 Boiling C =50 C
=40' C ~50 p p p point, vol vol VO1 FC 'C. percent percent percent 125 -48.5 6.5 19.5 ~ 6.5 134 -19.7 8.5 25.0 8.5 134x -26.5 7.0 20.5 7.0 124 -12.0 6.5 19.0 6.5 124a -10.2 ~ 6.5 19.0 6.5 123 27.9 6.9 17.0 6.0 123a 30.0 6.0 17:5 6.0 132 59.0 7.0 20.5 7.0 132c 48.4 6.5 19.0 6.5 Introduction of the appropriate gaseous fluoroethanes is easily accomplished by metering apprapriate quantities of the gas or gases into the enc~.osed air-containing co~apartment.
The air in the compartment can be treated at any time that it appears desirable. The modified air can be used continuously if a threat of fire is constantly present or if the particular environ~aent is, such that the, fire hazard must be kept at an absolute minimum: or the modified air can be used as an emergency measure if a threat of fire develops.
The invention w~:l.l be more clearly understood by referring to the examples which follow. The unexpected effects of the fluoroethane compositions, in suppressing and combatting fire, as well as its computability with the ozone layer and its relatively low greenhouse effect, when compared to other fire- .
combatting gases, particularly the perfluoroalkanes and Halon 1211, are shown in the examples.
iy0 92/0520 ~ ;; ;.j ~.~ ~.. ~ ,, PC!'/U590/06692 ..~.
_ ~0 Example 1 - Fire Extine~uishin~ Concentrations The fire extinguishing concentration of the fluoroethane compositions compared to several controls, was determined by the ICZ Cup Eurner method. This method is described in "Measurement of Flame-Extinguishing Concentrationsn F~. Hirst and K.
Booth, Fire Technology, Vol. 13(4): 296-315 (1977).
Specifically, an air stream is passed at 40 l0 liters/minute through an outer chimney (8.5 cm. I. D.
by 53 cm. tall) from a glass bead distributor at its base. A fuel cup burner (3.1 cm. O.D. and 2.15 cm.
I.D.) is positioned within the chimney at 30.5 cm.
below the top edge of the chimney. The fire ext~.nguishing agent is added to the air stream prior to its entry into the glass bead distributor while the air flow rate is maintained at 40 liters/minute for all tests. The air and agent flow rates are measured using calibrated rotameters.
Each test is conducted by adjusting the fuel level iri the reservoir to bring the liquid fuel level in the cup burner just even-;with the ground glass lip on the burner cup. With tha air flow rate maintained at 40 liters/minute, the fuel in the cup burner is ignited. 'The $ire extinguishing agent is added in measured increments until the flame is extinguished.
The fire extinguishing concentration is determined from the following equation:
Extinguishing concentration ~ F1 x 100 F
where F1 = Agent flow rate Fa ~ Air flow rate A
urn 9aioss2o ~crms~od~a~ ~. r 209~~~0 - 17. -Two different fuels are used, heptane and methanol; and the average of several values of agent flow rate at extinguishment is used for the following table.
Table 1 Extinguishing Concentrations of Certain Fluoroethane Comlaositions Compared to Other Agents Agent Fuel Flow Rate Heptane Methanol-Extinguishing Air Agent Conc.
(vol. (vol. (1/min) (1/min) %) %) Fe H~ Meth.
HCFC-123 7.1 10.6 40.1 3.06 4.75 HCFG-123a 7.7 10.1 40.1 3.37 5.11 HCFC-124 8.0 11.9 40.1 3.49 5.45 HFC-125 10.1 13.0 40.1 4.51 5.99 HFC-134a 11.5 15.7 40.1 5.22 7.48 CF4, r 20.5 23.5 40.1 10.31 12.34 C2F6 8.7 11.5 40.1 3.81 .5.22 H-1301* 4.2 8.6 40.1 1.77 3.77 H-1211** 6.2 8.5 40.1 2.64 3.72 .
CHF2C1 13.6 22.5 40.1 6.31 11.64 * CF3~r ** CF2ClBr WO 92/0520 _ ~ ~ ~ a ~ ~ ~ P~LT/'U590106G92~..-.,, - 1~ -Example 2 Cardiac Sensitivity The cardiac sensitivity or toxicity of the fluoroethanes, compared to several controls, was determined using the methods described in "Relative ' Effects of Haloforms and Epinephrine on Cardiac Automaticity~' R. M. Hopkins and J. C. Krantz, Jr., Anesthesia and Analgesia, vol. 47 no. 1 (1968) and "Cardiac Arrhythmias and Aerosol °Sniffing'°' C. F.
Reinhardt et al. Arch. Environ. Health vol. 22 (February 1971).
Specifically, the cardiac sensitivity is measured using unanesthesized, healthy dogs using the general protocal set forth in the Reinhardt et al article. First, far a limited period, the dog is subjected to air flow through a semiclosed inhalation system connected to a cylindrical face mask on the dog.
Then, epinephrine hydrochloride (adrenaline), diluted with saline solution, is administered intravenously and the electrocardiograph is recorded. Then air containing various concentrations of the agent being tested is administered followed by a second injectian of epinephrine. The concentrations of agent necessary to produce a disturbance in the normal conduction of an electrical~impulse through the heart as characterized by a serious cardiac arrhythmia, are shown in the following table.
v"~ 92/08520 ~ ~ ~ ~ ~ ~ ~ PCT/~.1~9'~~/0~692 Table 2 Threshhold Cardiac Sensitivity agent (vol. % in air) HFC-134a 7.5 H-1301* 7.5 CHF2C1 5.0 HCFC-124 2.5 HCFC-123 1.9 Ii-1211** 1 to 2 * CF3Br ** CF2CIBr ~Ca 92/08520 PGT/US90/06692..-., ~0~~6~.U
Example 3 The ozone depletion potential (ODP) of the fluoroethanes and various blends thereof, compared to various controls, was calculated using the method described in "'The Relative Efficiency of a Number of Halocarbon for Destroying Stratospheric Ozone" D. J.
Wuebles, Lawrence Livermore Laboratory report UCTD-18924, (January 1981) and "Chlorocarbon Emission Scenarios: Potential Impact on Stratospheric Ozone" D.
J. Wuebles, Journal Geophysics Research, 88, 1433-1443 (1983).
Basically, the ODP is the ratio of the calculated ozone depletion in the stratosphere resulting from the emission of a particular agent compared to the ODP resulting from the same rate of emission of FC-11 (CFC13) which is set at.lØ Ozone depletion is believed to be due to the migration of compounds containing chlorine or bromine through the troposphere into the stratosphere where these compounds are photolyzed by UV radiation into chlorine or bromine atoms. These atoms twill destroy the ozone (03) molecules in a cyclical reaction where molecular oxygen (02) and [C10] or [BrO] radicals are formed, those radicals reacting with oxygen atoms formed by UV
radiation of 02 to reform chlorine or bromine atoms and oxygen molecules, and the reformed chlorine or bromine atoms then destroying additional ozone, eta., until the radicals are finally scavenged from the stratosphere. 7Ct is estimated that one chlorine atom will destroy 10,000 ozone molecules and one bromine atom will destroy 100,000 ozone molecules.
The ozone depletion potential is also discussed in "Ultraviolet Absorption Cross-Sections of Several Brominated Methanes and Ethanes°° L. T. Molina, l~l. J. Molina and k'. S, Rowland" J. Phys. Chem. 86, "'~ 92/08520 ~ PC I /g1S90/06692 _ y 2672-2676 (1982); in Hivens et al. U.S. Patent 4,810,403; and in "Scientific Assessment of Stratospheric Ozone: 1989n U.N. Environment Programme (21 August 198J).
Tn the following table, the ozone depletion potentials are presented for the fluoroethanes used in this invention and various.controls.
Table 3 2.0 Ozone Depletion Agent Potenta.al HCFC123 0.013 HCFC1.24 0 . 013 HFC134a 0 CF4 . 0 CHF2C1 0.05 CF3CF2C1 0.4 W~ 92/08520 . F~CT/~US90/06692 ..-..
209~6~0 Example 4 The glabal warming potentials (GWP) of the fluoroethane and various blends thereof, compared to several controls, was determined using the method described in "Scientific Assessment of Stratospheric Ozane: 1989" sponsored by the U.N. Environment Programme.
The GRIP, also ltnown as the "greenhouse effect" is a phenomenon that occurs in the troposphere.
It is calculated using a model that incorporates parameters based on the agent's atmospheric lifetime and its infra-red cross-section or its infra-red absorption strength per mole as measured with an infra-red spectrophotometer.
The general definition is:
Calculated IR forcing GWP = due to agent Emission rate (steady state) of agent divided by the same ratio of parameters for CFC13.
In the following table, the GWP's are presented for the fluoroethanes and the controls.
Table 4 Global Warming Potential HFC-134a 0.220 HFC-125 0.420 HCFC-124 0.080 HCFC-1,2 3 0 . 015 CF4 greater than 5 C2F6 greater than 8 CHF2C1 0.29 CFC13 1.0 CF3CF2C1 8.2
Claims (6)
1. A process for preventing a fire in an enclosed air-containing area which contains combustible materials of the non-self sustaining type, the process comprising the steps of introducing into the air in said enclosed area an amount of CF3-CHF2 sufficient to impart a heat capacity per mol of total oxygen that will prevent combustion of the combustible materials in said enclosed area.
2. A process as in Claim 1 wherein the amount of said CF3-CHF2 in said enclosed area is maintained at a level of about 10 to 100 volume percent.
3. A process as in Claim 1 wherein the amount of said CF3-CHF2 in said enclosed area is maintained at about 20 volume percent.
4. A process as in Claim 1 wherein at least 1% of at least one halogenated hydrocarbon is blended with said CF3-CHF2 introduced into said enclosed area, said halogenated hydrocarbon being selected from the group consisting of difluoromethanel chlorodifluoromethane, 2,2-dichloro-1,1,1-trifluoroethane, 1,2-dichloro-1,1,2-trifluoroethane, 2-chloro-1,1,1,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetrafluoroethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 3,3-dichloro-1,1,1,2,2-pentafluoropropane, 1,3-dichloro-1,1,1,2,3-pentafluoropropane, 2,2-dichloro-1,1,1,3,3-pentafluoropropane, 2, 3-dichloro-1,1,1,3,3-pentafluoropropane, 1,1,1,2,2,3,3-heptafluoropropane, 1,1,1,2,3,3,3-hepta-fluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2,3-hexafluoro-propane, 1,1,2,2,3,3-hexafluoropropane, 1,2-dichloro-1,2-difluoroethane, 1,1-dichloro-1,2-difluoroethane, 3-chloro-1,1,2,2,3-pentafluoropropane, 3-chloro-1,1,1,2,2-pentafluoropropane, 1-chloro-1,1,2,2,3-pentafluoropropane, 3-chloro-1,1,1,3,3-pentafluoropropane, 3-chloro-1,1,1,2,2,3-hexafluoropropane, 1-ohloro-1,1,2,2,3,3-hexafluoropropane, 2-chloro-1,1,1,3,3,3-hexafluoropropane, 3-chloro-1,1,1,2,3,3-hexafluoropropane, and 2-chloro-1,1,1,2,3,3-hexafluoropropane.
5. A process for preventing a fire which comprises introducing a volume of CF3-CHF2 sufficient to provide a fire-preventing concentration in an enclosed area, and maintaining said concentration at a value of less than 80 volume percent.
6. A process as in Claim 5 wherein at least 1% of at least one halogenated hydrocarbon is blended with said CF3-CHF2 introduced into said enclosed area, said halogenated hydrocarbon being selected from the group consisting of difluoromethane, chlorodifluoromethane, 2,2-dichloro-1,1,1-trifluoroethane, 1,2-dichloro-1,1,2-trifluoroethane, 2-chloro-1,1,1,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetratfluoroethane, pentafluoroethane, 1,1,2,2-tetra-fluoroethane, 1,1,1,2-tetrafluoroethane, 3,3-dichloro-1,1,1,2,2-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 2,2-dichloro-1,1,1,3,3-pentafluoropropane, 2,3-dichloro-1,1,1,3,3-pentafluoropropane, 1,1,1,2,2,3,3-heptafluoropropane, 1,1,1,2,3,3,3-hepta-fluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2,3-hexafluoro-propane, 1,1,2,2,3,3-hexafluoropropane, 1,2-dichloro-1,2-difluoroethane, l,l-dichloro-1,2-difluoroethane, 3-chloro-1,1,2,2,3-pentafluoropropane, 3-chloro-1,1,1,2,2-pentafluoropropane, 1-chloro-1,1,2,2,3-pentafluoropropane, 3-chloro-1,1,1,3,3-pentafluoropropane, 3-chloro-1,1,1,2,2,3-hexafluoropropane, 1-chloro-1,1,2,2,3,3-hexafluoropropane, 2-chloro-1,1,1,3,3,3-hexafluoropropane, 3-chloro-1,1,1,2,3,3-hexafluoropropane, and 2-chloro-1,1,1,2,3,3 hexafluoropropane.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US1990/006692 WO1992008520A1 (en) | 1990-11-15 | 1990-11-15 | Fire extinguishing composition and process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2095640A1 CA2095640A1 (en) | 1992-05-16 |
| CA2095640C true CA2095640C (en) | 2004-10-19 |
Family
ID=32961126
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002095640A Expired - Lifetime CA2095640C (en) | 1990-11-15 | 1990-11-15 | Fire extinguishing composition and process |
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| Country | Link |
|---|---|
| EP (1) | EP0557275B1 (en) |
| JP (1) | JP3558630B2 (en) |
| CA (1) | CA2095640C (en) |
| DE (1) | DE69028119T2 (en) |
| ES (1) | ES2090301T3 (en) |
| WO (1) | WO1992008520A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5040609A (en) * | 1989-10-04 | 1991-08-20 | E. I. Du Pont De Nemours And Company | Fire extinguishing composition and process |
| AU2002951075A0 (en) * | 2002-08-29 | 2002-09-12 | Commonwealth Scientific And Industrial Research Organisation | Twin roll casting of magnesium and magnesium alloys |
| US8444873B2 (en) | 2009-06-12 | 2013-05-21 | Solvay Fluor Gmbh | Refrigerant composition |
| EP2594319B1 (en) | 2011-11-18 | 2018-05-30 | Minimax GmbH & Co KG | Assembly for extinguishing or making inert with a synthetic liquid extinguishing agent |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1926395A (en) * | 1930-07-31 | 1933-09-12 | Frigidaire Corp | Process of preventing fire by nontoxic substances |
| GB1132636A (en) * | 1965-09-22 | 1968-11-06 | Montedison Spa | Improvements in or relating to flame-extinguishing compositions |
| NL7006794A (en) * | 1969-05-16 | 1970-11-18 | ||
| US3844354A (en) * | 1973-07-11 | 1974-10-29 | Dow Chemical Co | Halogenated fire extinguishing agent for total flooding system |
| US4459213A (en) * | 1982-12-30 | 1984-07-10 | Secom Co., Ltd. | Fire-extinguisher composition |
| US4954271A (en) * | 1988-10-06 | 1990-09-04 | Tag Investments, Inc. | Non-toxic fire extinguishant |
-
1990
- 1990-11-15 WO PCT/US1990/006692 patent/WO1992008520A1/en not_active Application Discontinuation
- 1990-11-15 ES ES91901121T patent/ES2090301T3/en not_active Expired - Lifetime
- 1990-11-15 EP EP91901121A patent/EP0557275B1/en not_active Revoked
- 1990-11-15 JP JP50148091A patent/JP3558630B2/en not_active Expired - Fee Related
- 1990-11-15 CA CA002095640A patent/CA2095640C/en not_active Expired - Lifetime
- 1990-11-15 DE DE69028119T patent/DE69028119T2/en not_active Revoked
Also Published As
| Publication number | Publication date |
|---|---|
| CA2095640A1 (en) | 1992-05-16 |
| ES2090301T3 (en) | 1996-10-16 |
| JPH06501628A (en) | 1994-02-24 |
| DE69028119T2 (en) | 1997-02-20 |
| EP0557275A4 (en) | 1993-09-29 |
| EP0557275B1 (en) | 1996-08-14 |
| JP3558630B2 (en) | 2004-08-25 |
| WO1992008520A1 (en) | 1992-05-29 |
| EP0557275A1 (en) | 1993-09-01 |
| DE69028119D1 (en) | 1996-09-19 |
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| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121202 |