RU2068718C1 - Method of extinguishing fires - Google Patents

Abstract

FIELD: fire extinguishing. SUBSTANCE: fire-extinguishing compounds, one or more of which are brought into the fire while maintaining their concentration until fire is put out, are selected from the following group of fluorohydrocarbon compounds: pentafluoroethane, 1,1,1,3,3,3- hexafluropropane, 1,1,1,2,3,3-hexafluoropropane, heptafluoropropane. These compounds may also be used in mixtures with one or more compounds selected from the following group of chloro- and/or bromocarbon or -hydrocarbon compounds:

Description

This invention relates to a method of extinguishing fires and mixtures using higher fluorinated C ₂ and C ₃ saturated fluorocarbons.

 Known methods of extinguishing a fire by supplying a fire extinguishing composition to the fire containing a halocarbon compound.

However, in addition to the halocarbon compound, these formulations contain protein and / or its decomposition products and liquid polyhydroxy compounds [1] or terpenes and unsaturated oils [2]
The objective of the invention is to provide a method of extinguishing fires in which the flame is extinguished as quickly and efficiently as in the technology currently used with halocarbon compounds, which, however, does not destroy the ozone layer of the earth, does not create a greenhouse effect.

 The essence of the invention.

The task can be achieved by using saturated higher fluorinated fluorocarbons and their mixtures as fire extinguishers for use in methods and devices for fighting fires. The method of the invention includes introducing into the fire saturated C ₂ or C ₃ higher fluorinated fluorocarbon in a fire extinguishing concentration and maintaining this concentration until the fire is extinguished. Saturated higher fluorinated fluorocarbons of this invention include compounds of the formula C _x H _y F _z , where x 2 or 3, y 1 or 2, and z 5, 6 or 7; where y 1 and z 5 if x 2, and where z 6 or 7 if x 3. Specific fluorocarbons useful for this invention include heptafluoropropane (CF ₃ CHFCF ₃ ), 1,1,1,3,3,3 -hexafluoropropane (CF ₃ CH ₂ CF ₃ ), 1,1,1,2,3,3-hexafluoropropane (CF ₃ CHFCHF ₂ ) and pentafluoroethane (CF ₃ CHF ₂ ). These fluorocarbons can be used separately, in a mixture with each other or as a mixture with other fire extinguishing agents. Typically, fire extinguishing agents are used in concentrations ranging from 3 to 15%, preferably 5 to 10% volume per volume.

 Since such fluorocarbons do not contain bromine or chlorine, their ozone destruction potential is zero. In addition, since the compounds contain hydrogen atoms, they are subject to decomposition in the lower atmosphere, and, therefore, do not pose a threat, like gases of the greenhouse effect.

 These compounds can be used alone or in mixtures with each other or in mixtures with other extinguishing agents.

Among the other agents to which fluorocarbons of this invention can be combined are chloro and / or bromine compounds such as CF ₃ Br, CF ₂ BrCF ₂ Br, CF ₃ CF ₂ Cl, CF ₂ BrCl and CF ₃ CHFBr. Mixtures of heptafluoropropane and CF ₂ HBr are particularly preferred since the compounds have the same vapor pressure over a wide temperature range, and therefore the composition of the mixture remains relatively constant during exit or other use.

 If fluorocarbons are used in mixtures, they comprise at least about 10 weight. from the mixture. In such mixtures, it is desirable to use more hydrocarbons in order to minimize the environmental impact of chlorine and bromine-containing agents.

Saturated higher fluorinated C ₂ and C ₃ fluorocarbons can be effectively used at any minimum concentration at which the fire is extinguished, the exact minimum level depends on the specific combustion material, specific fluorocarbon and combustion conditions. However, better results are achieved if fluorocarbons or mixtures thereof are used at a level of at least about 3% (v / v). When using only fluorocarbons, the best results are achieved when the agent content is at least about 5% (vol./vol.). In the same way, the maximum amount used will be governed by considerations of economy and potential toxicity to living organisms. About 15% (v / v) provides a suitable maximum concentration for the use of fluorocarbons and their mixtures in populated areas. Concentrations above 15% (v / v) can be used in uninhabited areas, with a thin concentration determined by the specific combustion material selected by the fluorocarbon (or mixture) and combustion conditions. A preferred concentration of fluorocarbon agents, mixtures thereof, and mixtures with other agents in accordance with this invention is a concentration of about 5 to 10% (v / v).

 Fluorocarbons may be used using conventional application techniques and methods.

 Thus, these compositions can be used in a general fire extinguishing system by jet throwing, in which the agent is introduced into an enclosed space (for example, a room or other room) and directed to a flame in a concentration sufficient to extinguish the fire. According to the general extinguishing system, the device, equipment, or even rooms and rooms can be equipped with a source of fire extinguishing agent and appropriate hoses, valves and control devices that allow you to automatically and / or manually operate them in appropriate concentrations in case of fire. It is known that extinguishing compositions can be subjected to compression with nitrogen or other inert gas up to 600 atm under ambient conditions.

 Fluorocarbon agents can be used through conventional portable fire extinguishers. In them, the pressure is increased by nitrogen or other inert gases so that the agent is completely discharged from the fire extinguisher. Systems containing fluorocarbon can be compressed to any desired pressure up to 600 atm under ambient conditions.

 In practice, the present invention is illustrated by the following examples.

 Example 1

 To test the extinction of a static flame, a box of 28.3 cubic liters was designed (fire extinguishing). The box was equipped with a plexiglass inspection window and an inlet in the upper part for introducing the agent, in addition, an air inlet in the lower part. For the purpose of testing the agent, a dish (glass) measuring 90 x 50 mm was placed in the center of the box and 10 g of the liquid used in the lighters was filled. The liquid ignited and burned for 15 seconds before the introduction of the agent. During combustion, air was introduced into the box through the bottom opening. After 15 seconds, the air inlet was closed and a fire extinguishing agent was introduced into the box. It was supplied in an amount sufficient to provide an agent concentration of 6.6% v / v. Extinguishing time was measured, i.e. the time after the agent was supplied and before the flame was extinguished. The average blanking time for the agent with a concentration of 6.6% vol./about. given in table 1.

 Example 2

 The experiment was carried out as in example 1 using heptane as fuel. The average quenching time for a concentration of 6.6% vol./about. the same agents are also given in table 1.

 Table 1 shows the flame extinguishing time required for various combustible substances when using an agent with a concentration of 6.6% v / v. At this concentration, heptafluoropropane is also effective in extinguishing n-heptane flames as bromine-containing agents, and almost as effective as other agents in extinguishing flames from lighter fluid.

 In accordance with the invention, concentrations of about 5-10% are preferred for the general use of pure fluorocarbons. The use of a small amount of the agent may not achieve the goal and lead to the formation of smoke and the release of HF due to the combustion of the agent. The use of excess amounts is uneconomical and can lead to dilution of the level of oxygen in the air to concentrations harmful to living organisms.

 Example 3

 Example 1 was repeated with two white mice in a box. After extinguishing the flame, the mice remained in the box for another 10 minutes and were exposed to the products of combustion. After this procedure, the mice did not show symptoms of malaise and their behavior was normal after removal from boxing.

 Example 4

Dynamic combustion test data for heptafluoropropane and 1,1,1,2,3,3-hexafluoropropane were obtained using a test procedure in which air and n-butane were continuously supplied to a flame in a glass bowl-shaped burner. The vapor of the test agent was mixed with air and supplied to the flame, and the concentration of the agent gradually increased to the level necessary to extinguish the flame. Data were obtained for heptafluoropropane and 1,1,1,2,3,3-hexafluoropropane and, for comparison, for the following other halon agents: CF ₃ Br, CF ₂ BrCl, CF ₃ CF ₂ Cl, CF ₃ CF ₂ H and CF ₄ . The percentage of each substance in the air (v / v) required to extinguish the flame is given in table 2.

 Example 6

Heptafluoropropane and CF ₃ Br, CF ₂ BrCl and CF ₂ CF ₂ Cl were used to extinguish an n-heptane diffuse flame as in Example 4. These tests are shown in Table 3.

The dynamic combustion test data shown in Tables 2 and 3 demonstrate that the use of heptafluoropropane and pentafluoroethane is significantly more effective than the use of other known non-bromo or chlorine compounds. Moreover, heptafluoropropane can be compared in terms of effectiveness with CF ₃ CF ₂ Cl, a chlorine-containing chlorofluorocarbon. Their comparison is shown in relation to n-heptane, as well as n-butane. Although bromine and chlorine-containing agents, such as CF ₃ Br and CF ₂ BrCl, are slightly more effective than fluorocarbon agents in a bowl-burner test, the use of these agents is quite effective and has no environmental restrictions.

 Example 6

The static flame quenching data in the box were obtained for 1,1,1,3,3,3-hexafluoropropane with a test box volume of 35.2 cubic liters. in accordance with Example 1. In addition to 1,1,1,3,3,3-hexafluoropropane, for comparison purposes, CF ₃ Br, CF ₂ BrCl and CF ₃ CF ₂ Cl were also tested. All test agents were fed at a concentration of 5.5% (v / v).

The data in table 4 demonstrate that 1,1,1,3,3,3-hexafluoropropane is a highly effective fire extinguisher. It is almost as effective as CF ₃ CF ₂ Cl, chlorofluorocarbon, and quite effective compared to bromine-containing halons, such as CF ₃ Br and CF ₂ BrCl and is preferred due to the lack of properties to destroy ozone and other harmful effects that chlorine and bromine-containing halons.

 In addition to the properties of a highly effective fire extinguishing agent, 1,1,1,2,3,3-hexafluoropropane is toxicologically safe.

 The following examples demonstrate the effective use of fluorocarbon agents in mixtures or compositions including bromine-containing halon fire extinguishers.

 Example 7

The dynamic test data using the bowl-burner procedure of Example 4 were obtained for various mixtures of heptafluoropropane and CF ₂ HBr. Air and a mixture of agents were continuously supplied to the n-heptane diffuse flame in a bowl-shaped burner. For a given heptafluoropropane stream, the CF ₂ HBr stream slowly increased until the flame went out. The experiment was repeated at various heptafluoropropane flow rates and the results are shown in Table 6.

Table 6 shows the actual percentage of air volume. The calculated weight is also shown there. heptafluoropropane in the mixture. In addition, Table 6 indicates the ozone depletion potential for each agent ("PRO"). ABM data were calculated as follows: ABMs for pure compounds were calculated using the following formula:
PRO A E P [/ # Cl / ^B + C / # Br / • D ^{(# C-1)}
In this expression, P is the photolysis factor. P 1.0, if there are no special structural features that make the molecule susceptible to tropospherical photolysis. In other cases, P F, G, or H, as indicated in the Constant Table (Table 5).

 PRO for mixtures were obtained by multiplying the weight. agent on missile defense net agent.

These data demonstrate that effective flame quenching can be achieved with mixtures of heptafluoropropane and CF ₂ HBr and that missile defense CF ₂ HBr can be significantly reduced by adding heptafluoropropane to it.

 Examples 8 to 11.

Tables 7, 8, 9, and 10 show the diffuse flame quenching data obtained in Example 7 for the following agent mixtures:
Table 7 Heptafluoropropane and CF ₂ BrCl
Table 8 Heptafluoropropane and CF ₃ Br
Table 9 Pentafluoroethane and CF ₂ HBr
Table 10 1,1,1,2,3,3-hexafluoropropane and CF ₂ HBr
These tables also contain PRO data for pure CF ₂ BrCl and CF ₃ Br (literature data) and PRO for CF ₂ HBr (calculated). PRO for mixtures were obtained by multiplying the weight. agent on missile defense net agent.

The data in Tables 7-10 demonstrate that the various mixtures of fluorocarbons in accordance with this invention with chlorine and bromine-containing substances are effective fire extinguishing agents, and that, in accordance with this invention, it is possible to achieve a significant reduction in missile defense of chlorine and bromine-containing materials with their mixture with fluorocarbons. Saturated higher fluorinated C ₂ and C ₃ fluorocarbons such as heptafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane and pentafluoroethane, as currently used chlorine - and bromine-containing substances, are not destructive agents, and are especially useful where purification of the medium is a problem. Other uses of the fluorocarbons of this invention are the extinguishing of fires caused by the ignition of liquid and gaseous combustibles, wood, paper, textiles, solid combustibles, the protection of electrical equipment, computers, data processing devices and control rooms. TTT1 TTT2 TTT3 TTT4

Claims (8)

 1. A method of extinguishing a fire, comprising supplying a fire extinguishing halocarbon compound to the fire with maintaining its concentration until the fire is extinguished, characterized in that one or more fluorocarbon compounds selected from the series pentafluoroethane, 1,1,1,3 are used as a halocarbon compound , 3,3-hexafluoropropane; 1,1,1,2,3,3-hexafluoropropane; heptafluoropropane.  2. The method according to claim 1, characterized in that when quenching maintain the concentration of one or more fluorocarbon compounds less than 15 vol./about.  3. The method according to claim 1, characterized in that one or more fluorocarbon compounds are fed into the fire in the form of a continuous stream.  4. The method according to claim 1, characterized in that one or more fluorocarbon compounds are used in a portable fire extinguisher system. 5. A method of extinguishing a fire, comprising supplying a fire extinguishing halocarbon compound to the fire with maintaining its concentration until the fire is extinguished, characterized in that as a halocarbon compound, a mixture is used consisting of one or more fluorocarbon compounds selected from the series: pentafluoroethane, 1.1 , 1,3,3,3-hexafluoropropane, 1,1,1,2,3,3-hexafluoropropane, heptafluoropropane and one or more chlorine and / or bromocarbon compounds selected from the group: CF ₃ Br, CF ₂ BrCl, CF ₂ BrCF ₂ Br, CF ₂ HBr, CF ₃ CHFBr with one or concentration b Lee fluorocarbon compounds up to 10% by weight of the mixture.  6. The method according to claim 5, characterized in that during the quenching, the concentration of the mixture is maintained from 3 to 15 vol / vol.  7. The method according to p. 5, characterized in that the mixture is fed into the fire in the form of a continuous stream.  8. The method according to claim 5, characterized in that the mixture is used in a portable fire extinguisher system.

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