US3578590A - Fire-extinguishing composition comprising ethoxylated alkylphenol and ethylene glycol mono lower alkyl ether - Google Patents

Abstract

AN IMPROVED FIRE-FIGHTING COMPOSITION OF AN ETHOXYLATED ALKYLPHENOL AND AN ETHYLENE GLYCOL MONO LOWER ALKYL ETHER HAS BEEN DISCOVERED. THIS IMPROVED FIRE-EXTINGUISHING COMPOSITION IS USEFUL AS A WETTING AGENT, EMULSIFYING AGENT, LOW-EXPANSION OR HIGH-EXPANSION FOAM AND PERFORMS EXCEPTIONALLY WELL IN THE PRESENCE OF BOTH FRESH AND SALT WATER.

Description

United States Patent 3,578,590 FIRE-EXTINGUISHING COMPOSITION COM- PRISING ETHOXYLATED ALKYLPHENOL AND ETHYLENE GLYCOL MONO LOWER ALKYL ETHER Darle Lee Nieneker, Austin, and Leslie Preston Williams,

Groves, Tex., assignors to Jefferson Chemical 'Company, Inc., Houston, Tex. No Drawing. Filed Aug. 19, 1968, Ser. No. 753,714 Int. Cl. A62d 1/00; 1301f 17/42 U.S. Cl. 252--8.05 3 Claims ABSTRACT OF THE DISCLOSURE An improved fire-fighting composition of an ethoxylated alkylphenol and an ethylene glycol mono lower alkyl ether has been discovered. This improved fire-extinguishing composition is useful as a wetting agent, emulsifying agent, low-expansion or high-expansion foam and performs exceptionally well in the presence of both fresh and salt water.

BACKGROUND OF THE INVENTION The problem of extinguishing fires has plagued mankind throughout recorded history. Today in sophisticated society many improvements have been made and are being made to combat this age-old problem. With increased industrialization and particularly the exploitation of petroleum resources through petrochemicals, the science and are of fire extinguishing has become quite sophisticated. Fires have now become classified into various categories which vary according to the material involved and according to the mode of extinguishing a fire involving this material.

Our invention relates particularly to two classifications: those of ordinary combustible solids, or Class A materials, which include things like wood, cotton, paper, etc.; and Class B materials, which are flammable liquids such as gasoline, hexane, benzene and other aromatics and other liquid flammable hydrocarbons. Of special interest are the various polar solvents such as acetaldehyde, methyl ethyl ketone, 2-ethylhexanol, and the like. These polar solvents have previously been extremely difiicult, if not impossible in some instances, to extinguish when burning.

Many methods of extinguishing fires and fire-extinguishing compositions have been explored by those interested in fire safety. Varied methods have been used, such as Water alone particularly for the Class A type fire mentioned above. In addition, dry chemicals have been used in attempts to extinguish many Class B fires. In attempts to smother the fires, many of these dry chemicals are used as a foam produced by mixing two chemicals, such as aluminum sulfate and sodium bicarbonate, which contain a foaming agent and a stabilizer.

Another method which has been often used in fighting Class B fires is with mechanical foam solutions where the foam is made with liquid inducted into the water stream before it comes into contact with air to form the foam. These mechanical-type foam liquids or fire-extinguishing compositions are generally classified as protein and nonprotein, synthetic compositions.

The protein-type concentrate usually contains a high molecular weight polypeptide formed by the chemical hydrolysis of vegetable or animal proteins from which it is made. Various metallic salts are included with these protein liquids to give strength to the foam bubbles in the presence of heat and the foam-forming mechanical action itself. Protein foams by and large base their fireextinguishing ability upon the formation of a thick blanket of foam which smothers the fire. Protein foams are genice erally classified as a low-expansion foam. The various expansion-type classifications will be discussed hereinafter.

The synthetic mechanical foams are produced from concentrates which contain various types of synthetic detergents and are capable of foam formation in suitable foam-generating equipment. While there are several synthetic-type concentrates on the market, it is generally necessary to maintain supplies of more than one concentrate in order to have a fire-fighting capability against the various types of fires. Additionally, each of these different type synthetic concentrates requires specialized equipment for the use thereof depending upon whether it is high expansion, medium expansion, low expansion, an emulsification or a wetting agent. Thus, an installation, to have fire-fighting capability against a broad range of flammable hazards, must purchase various types of fire-fighting material and a variety of equipment with which to use the specialized material.

Accordingly, it has been found that most of the commercially available mechanical foam materials, both protein and synthetic, are substantially inelfective in fighting fires where polar solvents are involved. Accordingly, many fire-extinguishing concentrates are sensitive to whether they are used with salt water or fresh water. This is important when it may be necessary to extinguish a dockside or shipboard fire where a flammable water immiscible liquid is involved.

As hereinbefore mentioned, the fire-fighting compositions are categorized according to various classifications of material. Various fire-fighting compositions are generally called wetting agents, emusifying agents, low, high or medium-expansion foams. A wetting agent is generally used when fighting a Class A fire to improve the soaking characteristics of the water coming in contact with the flammable material.

An emulsifying agent is used in fighting a flammable liquid fire and acts to combine with some of the flammable material, emulsifying it, thus producing a firm of sorts on the burning material. High-expansion foams are those which produce a foam of a volume between and 1,000 times that of the liquid used in fighting the fire. Medium-expansion foams generally range from about 10 times to 100 times the volume of the liquid and those below a ratio of 10 to 1 are known as low-expansion foams.

In copending application Ser. No. 561,342, filed June 29, 1966, now abandoned, it was disclosed that a burning liquid fire could be extinguished by applying to the burning liquid a foam produced by passing through an air expansion nozzle a mixture of water with 2 to 6 volume percent of a nonionic surfactant having the formula: RO(CH CH O) H wherein R is selected from the class consisting of alkyl groups containing from 4 to about 20 carbon atoms and alykylphenyl groups wherein the alkyl chain contains from about 4 to about 15 carbon atoms and n is a number of from about 4 to about 30. This material, though acceptable for extinguishing burning liquid fires in certain circumstances, had some inherent disadvantages. It was found that small amounts of water introduced into the concentrate caused gelation, rendering the concentrate totally unusable for fire-fighting purposes. The resulting gelation makes the material useless for further fire protection. As was also disclosed in the copending application, the nonionic surfactant had a relatively high freezing point. Even though ethylene glycol was added thereto to reduce the freezing point to usable temperature, the gelation problem still remained.

Accordingly, it is an object of our invention to provide a fire-fighting composition which is adaptable for the extinguishment of Class A and Class B fires.

It is a further objective of our invention to provide 3 a fire-fighting composition which is useful either in salt or fresh water.

It is a further object of our invention to provide a firefighting composition which will be useful over a broad spectrum of applications from wetting agent through highexpansion foam.

It is a further object of our invention to provide a firefighting composition which does not gel when contacted with a small amount of water.

It is a further object of our invention to provide a firefighting composition which produces a foam stable under conditions where it is subjected to an overhead water s ra F rther objects and advantages of our invention will be apparent to those skilled in the art upon reading the description which follows. Such objects and advantages are intended to be included within the scope of our invention.

SUMMARY OF THE INVENTION Our invention relates to an improved fire-fighting composition which is useful as a wetting agent, emulsifying agent or as an expanded foam in fighting Type A and Type B fires, including polar solvent fires, and the method of fighting said fires with our improved fire-fighting composition. More particularly this invention is directed to an improved fire-fighting composition made up of a solution of an ethoxylated alkylphenol having the formula:

@owmcmomr wherein R is a C to C alkyl group and n has an average value of from 4 to about 30. The ethoxylated alkylphenol is mixed with an ethylene glycol mono lower aklyl ether in such proportions that the ether is present in the amount of about 0.1 to about 0.5 part by Weight per part of the ethoxylated alkylphenol.

The method of fighting fires involves incorporating the improved fire-fighting composition of our invention into a water stream and expelling the water stream to contact the burning material. If it is desired to use the fire-fighting composition as a wetting agent or emulsifying agent, it is expelled along with water through a standard nozzle which does not produce an expanded foam.

When expelled through a nozzle which introduces air into the liquid stream, an expanded foam results and is applied to the burning material. The fire-fighting composition is introduced into the water stream such that it makes up about 0.5 to about 6 volume percent of the aqueous solution, depending upon the type of fire involved and the classification of use; i.e., wetting agent or or expanded foam. Wetting agents are usually applied to burning materials at the lower concentrations, whereas the foamed material is generally applied at higher concentrations.

DESCRIPTION OF THE INVENTION Our invention involves a fire-fighting composition adaptable to a broad-spectrum application to various types of fires including Class A fires of combustible solids and Class B fires of flammable fluids, which include the hard-to-extinguish polar solvent fires.

Our improved fire-fighting composition is essentially a two-component system, which is blended together to form a homogeneous solution. One component is an ethoxylated alkylphenol having the general formula:

wherein R is a C to C alkyl group and n has an average value of from 4 to about 30. The other component is an ethylene glycol mono lower alkyl ether where the alkyl group has from 1 to 4 carbon atoms, such as ethylene glycol monomethyl ether, ethlyene glycol monoethyl ether, ethylene glycol monopropyl ether and ethlyene glycol monobutyl ether, etc. These two components are generally present together in amounts of about 0.1 to about 0.5 part by weight of the ethylene glycol mono lower alkyl ether per part by weight of the ethoxylated alkylphenol.

While this is essentially a two-component composition, it is also permissible to include in the concentrate a foam stabilizer such as high molecular weight polymers of ethylene oxide, polyvinyl resins, polyglycols and the like. The use of these materials is described in US. Pat. 3,258,423. An especially effective foam stabilizer has been found to be 2,0004,000 units of ethylene oxide in the polymer such as the commercially available polyethylene polymer, Polyox WSR-35. As taught by the aforementioned patent, these additives are included in an amount of from about 0.5 to 5 wt. percent of the concentrate.

It is also possible to store the concentrate with varying amounts of water present. That is to say, it is equally useful when inducted into the fire-fighting water stream as an aqueous solution as when the anhydrous concentrate itself is used. Of course it is best not to include too much water in the concentrate since the effectiveness of the material may be somewhat reduced. It is preferred that the amount of water be held to less than about 30% by weight.

When stored in an aqueous condition it is often advisable to include therein a corrosion inhibitor such as sodium benzoate or sodium nitrate or some other well known corrosion inhibitor which is compatible with this type of system. It is within the scope of our invention to include in our fire-fighting composition these additives as long as the above two components, i.e., the ether and the ethoxylated alkylphenol, are present in the proportions hereinabove mentioned.

The use of this improved fire-fighting composition is not limited to any one particular aspect, but is applicable to use as a wetting agent in fighting fires of Class A substances such as wood, mattresses, textiles, cotton and other combustible solids.

It is also applicable for use as an emulsifying agent to act upon flammable fluids to form a thin emulsion layer on the top thereof. And it is also useful in forming low, medium or high-expansion foams for fighting fires of Class B flammables such as aromatic distillates, benzene, toluene, xylene, gasoline, kerosene, fuel oil, jet fuel, hexane, heptane, octane, and the like. We have also discovered it to be particularly useful in fighting previously very difficultly extinguished fires involving polar solvents such as acetaldehyde, benzaldehyde, methyl ethyl ketone, ethyl acetate, butylacetate, and the like.

In addition, as the following examples will illustrate, our fire-fighting composition is useful even in the presence of salt water and extinguishes particularly difficultly controlled fires such as the polar solvents and hexane. This is true even when the fire is kindled in the presence of flashback hazards such as metal structure present in the fire pit.

Our foam has also proved to be stable when used in conjunction with water deluge sprays. This situation often occurs when a flammable liquid becomes ignited in a chemical plant or petroleum refinery or around a storage tank. Deluge sprays, while ineffective to extinguish the fire itself, are used to keep the structural metal from reaching a temperature at which its structural strength fails. Prior art foams have been found to disintegrate badly in the presence of a water deluge spray system.

The fire-fighting composition of our invention was found to be nongelling upon contact with minor amounts of water and also is readily soluble in water to form a homogeneous aqueous solution having outstanding fireextinguishing properties. Unlike many fire-fighting compositions, particularly the protein-type material, our improved fire-fighting composition does not deteriorate upon standing in storage nor does it present corrosion problems to the fire-fighting system in which it is to be used. However, one precaution is necessary when the material is stored as an aqueous solution concentrate. That is, it is necessary to incorporate therein an effective amount of a corrosion inhibitor.

Our invention will be further illustrated by the following examples which are intended to be merely for purposes of illustration and not to limit the scope of our invention.

EXAMPLE I A test fire of 100 gallons of aromatic distillate (flash point, 20 F.; initial boiling point, 115 F.; end point, 165 F.; Reid vapor pressure, 7 p.s.i.) was fought using a commercially available liquid protein base foam educted through a commercially available foam nozzle designed for use with protein foam rated by the manufacturer to deliver 3% by volume of the protein-based foam at a rate of 150 gallons per minute. The fire was extinguished using the protein based foam in approximately two minutes.

A like test fire of 100 gallons of the same aromatic distillate was extinguished by the use of a concentrate made up of 80% of a 9 mol ethylene oxide adduct of nonyl phenol and 20% of ethylene glycol monoethyl ether. This concentrate was educted and foamed through the same commercially available equipment used with the proteintype concentrate into a stream of water in a ratio of 3% by volume of the concentrate and 97% by volume of water. This mixture was expanded with air by the use of a commercially available expansion nozzle rated at 150 gallons per minute and applied to the fire. The fire was extinguished by this foam in approximately thirty seconds.

This example illustrates the improved fire-fighting properties of the fire-fighting composition of our invention.

EXAMPLE II In a test pit having a 400 square foot area, 150 gallons of hexane, flash point 0 to 24 F., was allowed a thirty-second preburn. This pit also contained metal structures as flashback hazards. In addition, there were twelve 0.35-gallon per minute sprinklers over the 400 square foot pit discharging water into the pit. The concentrate of Example I was educted into the water stream to provide a 3% concentrate aqueous solution. The water/concentrate solution was expanded through two lIO-gallon per minute nozzles and applied to the fire. The fire was extinguished in one minute and thirty seconds.

The previous example illustrates the ability of the firefighting composition of our invention to extinguish a hydrocarbon fire involving a flammable liquid having a very low flash point. It also illustrates the stability of the foam produced using the concentrate of our invention in the presence of a water deluge spray. From this example, it will be seen that our fire-fighting composition performs wells on low flash point hydrocarbons and also retains a stable blanket in the presence of foam interfering conditions.

EXAMPLE III Under the conditions and procedures followed in Example II, a test fire of 150 gallons of acetaldehyde was extinguished in thirty seconds. This example illustrates the applicability of the fire-fighting composition of our invention to the extinguishment of fires involving polar solvents.

EXAMPLE IV Following the conditions and procedures of Example II, a test fire of 150 gallons of benzene was extinguished in forty seconds. Benzene has a flash point of approximately 12 F.

EXAMPLE V In a pit 120 feet by 14 feet having flashback hazards, 4,000 gallons of aromatic distillates was ignited and allowed a two-minute preburn. This fire was extinguished with a 1%" diameter, gallons per minute foam nozzle, using a 3% solution of the concentrate of Example I. The fire was extinguished in one minute and fifty seconds, requiring approximately 200 gallons of the water/ concentrate solution or approximately /a of a gallon per square foot of fuel bed.

Fires have also been extinguished where the fuel was gasoline, ethyl ether, acetone, isopropyl acetate, ethyl acetate, isobutyl acetate, fuel oil and ethanol and aldehyde ether combinations. These tests were performed using standardly available equipment producing both low-expansion and high-expansion mechanical foams. These fires were also controllable while additional fuel was being sprayed into the test fire from an overhead line, simulating the problem involved when fighting a fire in a manufacturing facility where a transfer line had become ruptured spilling additional fuel into an ignited pool of fuel.

We have found that the fuel fires can either be extinguished utilizing the composition of our invention by playing the foam at the base of the fire at its edge and progressively pushing the fire in front of it across the pool of flammable liquid. This can also be done through utilizing a foam chute which is a chamber in which the water/concentrate solution is foamed and discharged by flowing it into the flaming liquid. As the quantity of foam produced increases, the fire is pushed by the foam until it is extinguished.

An additional advantage we have discovered in the practice of our invention is that there is practically no water lost through the foam nozzle due to dripping and that all the water expelled from the nozzle is included in the foam itself.

Obviously, from the foregoing teachings, many modifications and variations of the present invention are possible. It is therefore to be understood that it is within the scope of the appended claims to practice the invention otherwise than is specifically described herein.

We claim:

1. An improved fire-fighting composition useful as a wetting agent, emulsifying agent or as an expanded foam, consisting essentially of a concentrate solution of an ethoxylated alkyl phenol and an ethylene glycol mono lower alkyl ether wherein the ethoxylated alkyl phenol is represented by the formula:

where R is a C to C alkyl group and n has an average value of from 4 to about 30 and the ethylene glycol mono lower alkyl ether is present in the amount of about 0.1 to about 0.75 part by weight of the ethoxylated alkyl phenol and wherein the ethylene glycol mono lower alkyl ether is a C to C carbon atom ethylene glycol ether.

2. The composition of claim 1 wherein the concentrate solution is an aqueous solution comprising up to about 30% by weight water.

3. The composition of claim 2 wherein the aqueous solution contains a corrosion inhibitor.

References Cited UNITED STATES PATENTS 2,088,085 7/1937 Gross et al. 252351 2,413,667 12/1946 Urquhart 2528.05 2,529,211 11/1950 Busse et al. 2523 2,774,709 12/1956 Mayhew et al. 252351X 3,008,905 11/1961 Wedell 252307 3,258,423 6/1966 Tuve et al. 2523 3,282,843 11/ 1966 Alburger 25235 1X 3,457,172 7/ 1969 Stewart et al 2523 JOHN T. GOOLKASIAN, Primary Examiner D. J. FRITSCH, Assistant Examiner US. Cl. X.R. 2523, 307, 311, 351