Fire suppression compositions

Abstract

A fire suppression composition comprises CF.sub.3I and CO.sub.2, wherein said CF.sub.3I is present in an amount of from 23 mol. % to 39 mol. %, based on the total moles of CF.sub.3I and CO.sub.2 present in the fire suppression composition. Alternatively, the fire suppression composition comprises CF.sub.3I and CO.sub.2, wherein said CF.sub.3I is present in an amount of from 53 mol. % to 85 mol. %, based on the total moles of CF.sub.3I and CO.sub.2 present in the fire suppression composition.

Claims

1. A fire suppression composition comprising CF.sub.3I and CO.sub.2, wherein said CF.sub.3I is present in an amount of from 76 mol. % to 85 mol. %, based on the total moles of CF.sub.3I and CO.sub.2 present in the fire suppression composition, wherein a total amount of additional components are present in the fire suppression composition in an amount of up to 5 weight %, based on a total weight of the fire suppression composition.

2. The fire suppression composition according to claim 1, wherein the additional components are selected from one or more gases, additional fire suppressant compounds, odorants, or combinations thereof.

3. A fire suppression system or device containing the fire suppression composition as claimed in claim 1.

4. A fire suppression system or device according to claim 3, wherein said fire suppression system additionally comprises a dispensing component.

5. A method for preparing a fire suppression composition as claimed in claim 1, said method comprising: providing CF.sub.3I; providing CO.sub.2; providing the one or more additional components; and combining the CF.sub.3I, the CO.sub.2, and the one or more additional components to form a fire suppression composition as defined in claim 1.

Description

DETAILED DESCRIPTION

(1) CF.sub.3I is an environmentally friendly alternative to fire suppression agents like Halon 1301 because CF.sub.3I has a lower ozone depletion potential. The lower ozone depletion potential is due to the lower stability of the molecule. However, the lower stability (or the increased tendency to degrade) presents a challenge for storage and use of CF.sub.3I or blends containing CF.sub.3I as a fire suppression agent. The lower stability has discouraged the use of CF.sub.3I in fire suppression applications as it can decompose, thus reducing its efficacy. The present disclosure involves addition of CO.sub.2 to the CF.sub.3I, which has been found to improve stability of CF.sub.3I.

(2) When released, the CO.sub.2 is able to remove a large amount of heat from its surroundings (i.e. has a high latent heat of vaporization). This temperature reduction can reduce the severity of the fire, as well as reducing the decomposition rate of CF.sub.3I, maximizing the available CF.sub.3I present when the fire suppression composition is used to extinguish a fire.

(3) The presence of CO.sub.2 in the fire suppression composition can reduce the temperature of the atmosphere in the space to be protected to below 370° C. (700° F.), e.g. to below 360° C., to below 350° C., to below 340° C., to below 330° C., to below 320° C., or to below 315° C. (600° F.).

(4) CO.sub.2 is a physically acting fire suppression agent and CF.sub.3I is a chemically acting agent. Combining these two different types of agent as described herein results in a synergistic combination. More specifically, the blends of CO.sub.2 and CF.sub.3I as disclosed herein have been shown to be a synergistic combination. The combination of these two components has surprisingly resulted in a fractional inerting composition number of less than the sum of the two components when measured separately. The effect of this is that the combination of these two components has an enhanced ability to extinguish a fire than the two components would have had if used separately in the same amount.

(5) It has also been found that fire suppression compositions according to the present disclosure can have a reduced vapor pressure, and in some instances, a vapor pressure in the same range as that of conventional fire suppression agents such as Halon 1301. The reduced vapor pressure allows the fire suppression composition to be used in conventional hardware such as preexisting fire extinguishing containers and devices.

(6) The present disclosure will now be further described by way of the following non-limiting examples.

EXAMPLES

(7) Testing Procedure

(8) Testing was carried out against propane-air explosions in a 42 L sphere. The most explosive propane-air mixture is 4% propane in air. This concentration was therefore used to assess the relative performance of extinguishing agents and blends thereof.

(9) The sphere was evacuated. Whilst monitoring the pressure transducer, propane was added to a pressure of 0.04 atm (4% in the final mix). The agent or agents were added at the desired concentration. Air was then added to raise the pressure in the sphere to 1.00 atm. A fan can then be used to ensure that all the gases are mixed homogeneously throughout the sphere. A spark was ignited using a center point spark ignition and the pressure rise was monitored by a data logger. A pressure rise of 1 psi or lower is designated as a pass.

(10) The standards used for inerting testing are:

(11) ASTM E2079-07—the standard test method for limiting oxidant concentration in gases and vapors

(12) BS EN 1839:2012—determination of explosion limits in gases and vapors

(13) BS EN 15967:2012—determination of maximum explosion pressure and the maximum rate of pressure rise of gases and vapors.

(14) Fractional Inerting Contribution

(15) When assessing blends of components, the concept of fractional inerting contribution is used. This is defined as:

(16) $\mathrm{FIC}=\underset{i=1}{\overset{n}{.Math.}}\frac{C_i}{{\mathrm{IC}}_i}$
Where C.sub.i is the concentration of component i
And IC.sub.i is the inerting concentration of component i.
Thus, inerting should be attained when FIC=1 (i.e. the sum of individual concentrations has reached the overall required amount to achieve inerting). It therefore follows that if inerting is achieved at FIC less than 1, then the blend is more effective than the sum of its components. In other words, the blend is exhibiting synergy.
Blends of CF.sub.3I and CO.sub.2

(17) Blends of CF.sub.3I and CO.sub.2 were evaluated and it was found that successful inerting results were found at FIC values of lower than 1:

(18) TABLE-US-00001 TABLE I Rel. wt Rel. vol Pres to 6% to 6% Propane CF.sub.3I CO.sub.2 Mol rise Halon Halon Mol. % Example (Vol %) (Vol %) (Vol %) Ratio (psig) FIC 1301 1301 CF.sub.3I* 1 3.98 2.93 8.64 1:3 0.99 0.76 1.04 1.36 25.3 2 4.01 3.24 7.42 3:7 0.91 0.76 1.04 1.27 30.4 3 4.02 3.31 6.92  6:13 0.78 0.76 1.03 1.22 32.4 4 4.05 3.49 6.46  7:13 0.9  0.77 1.04 1.2  35.1 *Mol. % CF.sub.3I expressed as a proportion of the moles of CF.sub.3I and CO.sub.2

(19) TABLE-US-00002 TABLE II Rel. wt Rel. vol Pres to 6% to 6% Propane CF.sub.3I CO.sub.2 Mol rise Halon Halon Mol. % Example (Vol %) (Vol %) (Vol %) Ratio (psig) FIC 1301 1301 CF.sub.3I* 5 4.04 5.19 2.53 2:1 0.94 0.89 1.22 1.06 67.2 6 3.98 5.47 1.76 3:1 0.97 0.90 1.25 1.03 75.7 7 4.08 6.01 1.49 4:1 0.97 0.98 1.36 1.09 80.1 8 4.01 6.49 1.3  5:1 0.96 1.04 1.46 1.15 83.3 *Mol. % CF.sub.3I expressed as a proportion of the moles of CF.sub.3I and CO.sub.2

(20) As can be seen from Tables I and II above, all examples show a synergistic effect between the CF.sub.3I and CO.sub.2 in the blend. Examples 1-4 show a particularly good synergistic effect, coupled with an acceptable vapor pressure/temperature characteristics. Examples 5-8 show a synergistic effect, and these examples have improved vapor pressure/temperature characteristics.

(21) References to “comprises” and/or “comprising,” should be understood to also encompass “consist(s) of”, “consisting of”, “consist(s) essentially of” and “consisting essentially of”.

(22) The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.

(23) While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.