In terms of mechanical foam, mankind has used synthetic foam fire extinguishing agents since the beginning of last century. However, the effect of synthetic foam against oil fires is not ideal, so people developed protein foam. Aqueous film-forming foam, fluoroprotein foam, film-forming fluoroprotein foam. In order to deal with alcohol fires, people have developed anti-alcohol foam.
(1) Protein foam fire extinguishing agent
In 1922, Jennings of the American Standard Oil Company injected animal glue and ferrous sulfate onto the surface of gasoline to prevent it from evaporating and catching fire. This was the world's first use of protein foam for fire fighting.
Later, Germany's Wiesen Paul and Spema discovered that protein hydrolyzate is the best foam fire extinguishing agent. They placed the protein hydrolyzate and the sulfurous acid solution as two separate aqueous solutions. It was mixed during use, and the air was sucked in to stir and foam. Later, they added ferrous sulfate to the protein hydrolysate to use it as a concentrate, and developed the current protein foam. Their 5% concentration is mixed with fresh water and sea water to form 8 times the foam, which can stably stay on the surface of oil. Stamar of Hamburg, Germany is still selling this foam liquid.
In 1932, Germany's Total Company officially built a factory and began to produce protein foam.
In 1937, Raza developed a method of using hoof powder, albumin, globulin and other proteins as raw materials and using calcium hydroxide to decompose. This method was used in Britain and Germany after 1939.
In 1944, the British government approved the preparation method of adding ferrous sulfate to hoof horn powder after hydrolysis.
In 1945, the British official research institute published a research report by Clark and Derby. The report proposed a method of using animal blood, hoof horns and other raw materials, using caustic soda, calcium hydroxide and other alkalis or acids, and enzymes to decompose. The method of foam performance is described in detail. This research report is one of the most important research materials on foam fire extinguishing agents in the world so far. The well-known PB report is the technical research results of Germany during World War II, including the research results of foam fire extinguishing agents, which was transferred to the United States after the war. So far, the German Hyxter Company is still selling protein foam fire extinguishing agents called TUTOOGEL developed according to the research results reported by PB.
From the end of World War II to the early postwar period, the focus of foam fire extinguishing agent research shifted from Europe to the United States. In 1946, the United States formulated the Joint Army-Navy Technical Requirements (JAN-C-266) for protein foam fire extinguishing agents. The US military in Europe and Asia purchased protein foam liquids in accordance with this technical requirement, which had a great impact. For a time, almost all foam fire extinguishing agents all over the world used the same formula.
In the 1950s, Japan began to introduce petrochemical plants and they grew rapidly. At the same time, relevant Japanese researchers tried protein, fish meal, and bird hair as raw materials. They found that using caustic soda to decompose the dried blood of cattle and horses, and adding iron salts, the protein foam solution made can also reach JAN. -C-266 technical requirements, so that the raw materials of the protein foam liquid are more diversified.
In my country, in 1967, Shanghai Fire Equipment Factory and Beijing Fire Equipment Factory successfully developed 6% protein foam fire extinguishing agent. Later, domestically made protein foam fire extinguishing agent gradually replaced imported products.
(2) Fluoroprotein foam fire extinguishing agent
Protein foam has excellent thorough oil resistance and fire resistance when dealing with oil fires, but has the weakness of poor fluidity and the foam is easily contaminated by oil. In order to solve these problems, the National Foam Company of the United States developed a fluoroprotein foam with the product AER-O-FOAMXL in 1965. Fluoroprotein foam has good fluidity and is not easy to defoam when contaminated by oil. It can be used in the form of submerged spray. Immediately after National Foam Company, British Angus Company and ICI Company also made fluoroprotein foam liquid and sold it on the market as FP-70 products. In Europe and America, after the advent of fluoroprotein foam, it soon replaced protein foam as the mainstream fire extinguishing agent for protecting large oil tanks. Now, when it comes to protein foam, Europe and the United States generally refer to fluoroprotein foam. As the fluoroprotein foam produced by Angus has the most sales in this market, FP-70 has become synonymous with fluoroprotein foam in some places. However, the price of fluoroprotein foam is much higher than that of protein foam. In Japan, due to mandatory regulations, fluoroprotein foam is rarely used.
In 1982, the Tianjin Fire Fighting Research Institute of the Ministry of Public Security developed a fluoroprotein foam fire extinguishing agent, which was successively used in Beijing Fire Equipment Factory, Shenyang Yuhong Fire Equipment Factory, Luoyang Suburban Fire Fighting Agent Factory, Jiangdu Fire Fighting Agent Factory (now renamed Yangzhou Jiangya Fire Pharmaceutical Co., Ltd.) and more than 10 manufacturers put into production.
In 1993, the Tianjin Fire Research Institute of the Ministry of Public Security developed a multifunctional fluorine protein foam fire extinguishing agent and put it into production at Xinghua Fire Fighting Pharmaceutical Factory.
(3) Synthetic foam fire extinguishing agent
This kind of synthetic foam fire extinguishing agent is called Class A foam, and its composition is hydrocarbon surfactant. The original purpose of synthetic foam is to be used in Class A fires, not Class B fires. When encountering a very small-scale oil fire and only having surfactant foam on hand, a large number of sprays can also extinguish the fire, but the foam quickly destroys on the oil surface. Synthetic foam fire extinguishing agent is mainly used for medium and high expansion foam, but it can also be used as low expansion foam.
Surfactants are used as foam extinguishing agents earlier than protein foams. In 1903, Germany injected carbon dioxide and nitrogen into the ammonium soap aqueous solution to generate air bubbles.
In 1930, German Daimler, Zorus, etc. added animal glue as a stabilizer to sodium lauryl sulfate. In order to extend the water separation time, they added carboxymethyl cellulose and alcohols as an antifreeze, and continued their research. This surfactant is used in a 2-4% aqueous solution, and the foaming ratio can reach 10-18 times, but its oil resistance and fire resistance are not good, and it is not very effective against oil fires.
After World War II, after the US Army decided to use protein foam for the world's largest customer, synthetic surfactant foam disappeared from the market.
Since the 1960s, Japan's petrochemical industry has developed rapidly, producing a large number of various types of surfactants. As surfactant-type foam fire extinguishing agents only need to mix several raw materials and do not need to be produced by professional extinguishing agent manufacturers, Japanese detergent manufacturers, fire-fighting equipment manufacturers, and fire extinguisher manufacturers have produced more than 20 surfactant foams. Fire extinguishing agents are introduced to the market. Since this type of foam is not as good as protein foam when applied to oil fires at low multiples, people use them as high multiples to extinguish fires, that is, send a large amount of foam to the flame of oil to extinguish the fire. The high-expansion foam produced by the surfactant foam extinguishing agent can also be used to fight general construction fires.
As the Japanese economy continued to grow in the 1970s, there were more and more oil tankers and automobiles on the road, and oil burners became more and more popular in ordinary households. As a result, oil fires that were originally confined to oil tank farms and petrochemical companies were on the road. , The chance of housing occurrence has also greatly increased. In order to take corresponding countermeasures, local fire departments have purchased a lot of foam fire extinguishing agents based on surfactants. In 1975, Japan promulgated the "Ministry of Technical Requirements for Foam Extinguishing Agents", which also stipulated foam fire extinguishing agents based on surfactants, which gave people the illusion that this foam can extinguish petroleum fires and made Japan reserve The fire department of surfactant foam extinguishing agent has further increased, and synthetic surfactant foam extinguishing agent has entered a golden age in Japan.
In 2003, an oil tank fire occurred in the Tokachi Oki area of Japan in an earthquake. The fire brigade could not extinguish the fire with synthetic surfactant foam. Since then, most of the fire brigades have reached a consensus that surfactant foam cannot be used to extinguish oil fires.
Since then, Japan has rarely used surfactant foam to fight oil fires, and mainly used it as a type A foam for compressed air foam system (CAFS). However, because local fire brigades do not understand how large a fire is and how much to use, and it forms a bottleneck in terms of cost performance, the use of synthetic surfactant foam in fighting Class A fires has also been reduced.
In Europe and America, after World War II, synthetic surfactant foam was basically not used for oil fires. After the United States developed the compressed air foam system (CAFS) in the 1970s, the number of synthetic surfactant foams used as Class A foam increased. With the promotion of CAFS all over the world, the output of synthetic surfactant foam fire extinguishing agents used as Class A foams has also risen accordingly, and synthetic surfactant foam fire extinguishing agents have once again been favored by people.
In China, in 1975, six units including the Shanghai Fire Research Institute of the Ministry of Public Security and the Liaoning Coal Research Institute jointly developed a powder-type high-expansion foam fire extinguishing agent. In 1990, the Tianjin Fire Research Institute of the Ministry of Public Security developed the third generation of high-expansion foam fire extinguishing agent that is resistant to humidity and smoke, and it was put into production at Beijing Chuanhe Fire Fighting Material Factory.
(4) Aqueous film-forming foam fire extinguishing agent
Aqueous film-forming foam (AFFF) is the name of the United States, and many countries also call it fluorosurfactant foam because its main ingredient is fluorosurfactant.
Aqueous film-forming foam was invented in the United States. From 1946 to 1952, Twisman of the US Naval Institute of Technology found in the wettability of the research group that fluorosurfactants have both water repellency and oil repellency. The research institute's Chabu researched the application of fluorosurfactant as a fire extinguishing agent, and developed a combined system that uses it with dry powder fire extinguishing agent. The fluorosurfactant aqueous solution precipitated by the foam forms a thin film on the surface of the oil and floats on it to suppress steam generation and prevent re-ignition after the fire is extinguished. Because it forms a light water-based film on the surface of the oil, the U.S. Navy called it light water foam, and it was patented in 1964.
This patent was later transferred to 3M in the United States. After 3M still adopted the product "light water foam", other companies later also produced and sold this foam fire extinguishing agent. Due to the technical requirements of the military, the brand name could not be used This kind of foam was renamed as Aqueous Film Foam (AFFF). In 1979, Tianjin Fire Research Institute of the Ministry of Public Security and Shanghai Organic Research Institute jointly developed the first generation of aqueous film-forming foam fire extinguishing agent and put it into production at Qingdao Loushan Fire Equipment Factory. In 1995, the Tianjin Fire Research Institute of the Ministry of Public Security developed the third-generation multi-purpose aqueous film-forming foam fire extinguishing agent.
(5) Anti-alcohol foam fire extinguishing agent
In 1939, Germany's Daimler invented the addition of fatty acid zinc soap to the protein hydrolysis product to form a foam with anti-solubility. In 1950, Gimbel and Clinford added sodium alginate to surfactants. Makes foam resistant to solvents, because sodium alginate comes in contact with alcohol to form an insoluble gel. In 1952, American shellfish used surfactants and ethanolamine to disperse aluminum lactate and fatty acids in soy protein hydrolysate to make protein foam resistant to dissolution. Raza used ethanolamine to disperse fatty acid zinc soap in protein. the goal of. However, the fatal shortcoming of the anti-alcohol foam of metal soaps is too short to overcome. That is, the concentrated liquid will not foam when mixed with water for more than 2-3 minutes. Therefore, the piping must be short and cannot be used in fixed equipment. In 1974, Caesars in the United States discovered that polysaccharide polymers gelled after contacting alcohols, so they added it to fluorosurfactants and hydrocarbon surfactants to form alcohol-resistant foams and obtained a patent. This kind of foam forms an aqueous film on the surface of cyclohexanone, called AR-AFFF or AFFF-AR, and is now used a lot in Europe and America. Okiyama in Japan has developed anti-alcohol foam formed by adding fluorosurfactants to protein hydrolysis products. This kind of foam is different from the past anti-alcohol foam, it does not produce sediment in the aqueous solution, and can not only fight alcohol fires, but also fight gasoline and other petroleum fires. After the promotion and application of these two new types of anti-alcohol foams, metal soap anti-alcohol foams gradually disappeared. In my country, in 1976, the Shanghai Fire Research Institute of the Ministry of Public Security and the Shanghai No. 4 Synthetic Detergent Factory jointly developed a metal soap anti-alcohol foam fire extinguishing agent and put it into production at the Shanghai No. 4 Synthetic Detergent Factory.
(6) Film-forming fluoroprotein foam fire extinguishing agent
In the 1980s, the British company Ingels developed a film-forming fluoroprotein foam fire extinguishing agent. By the 1990s, the Tianjin Fire Research Institute of the Ministry of Public Security of my country also successfully developed a film-forming fluoroprotein foam fire extinguishing agent.