CN115212508A - Special water film-forming foam extinguishing agent for transformer oil fire and preparation method thereof - Google Patents

Abstract

The invention discloses a special water film-forming foam extinguishing agent for transformer oil fire, which relates to the technical field of extinguishing agents and is mainly prepared from the following raw materials in percentage by weight: 6-15% of fluorocarbon surfactant, 3-13% of hydrocarbon surfactant, 2-7% of solvent, 7-12% of cosolvent, 5-10% of foam stabilizer, 2-7% of corrosion inhibitor, 2-7% of antifreeze agent, 0.1-0.5% of chelating agent, 0.1-0.5% of thickening agent and 50-80% of water. The invention also provides a preparation method of the fire extinguishing agent. The invention has the beneficial effects that: the aqueous film-forming foam extinguishing agent has excellent film-forming speed and stable foaming performance through preparation proportion adjustment, and can more effectively cope with water-insoluble liquid fire.

Description

Special water film-forming foam extinguishing agent for transformer oil fire and preparation method thereof

Technical Field

The invention relates to the technical field of fire extinguishing agents, in particular to a special water film-forming foam extinguishing agent for transformer oil fire and a preparation method thereof.

Background

After the water film-forming foam extinguishing agent is sprayed out from the spray head, a water film and a foam layer are spread on the surface of the combustible liquid to extinguish fire. The water film-forming foam extinguishing agent is applied to various types of B-type fires, and the general fire extinguishing performance can extinguish the B-type fires of unleaded motor gasoline or mixed oil and polar solvent.

The fire extinguishing mechanism of the water film-forming foam extinguishing agent mainly comprises the isolating action, the suffocation action and the intercepting action of foam and the cooling action of water:

(1) And (4) isolation. Because of its relatively low density, the foam can float on the surface of the combustible liquid or adhere to the surface of the combustible solid, forming a foam blanket that insulates the surface of the comburent from air.

(2) Asphyxiation effect. The liquid after absorbing heat is vaporized to dilute the oxygen content of the air on the surface of the fuel liquid, so as to generate a suffocation effect on the fuel liquid and prevent the fuel liquid from being continuously heated, vaporized and combusted.

(3) The obstruction function. The water film formed on the oil surface by the water film forming foam liquid can effectively cover the fuel surface, the foam layer can shield the heat radiation of flame to the surface of a combustion object, the evaporation speed of combustible liquid or the thermal decomposition speed of solid is reduced, the volatilization of fuel molecules is inhibited, combustible gas is difficult to enter a combustion area, the damage effect to foam is weakened, and the sealing performance and the re-combustion resistance of the foam are enhanced.

(4) And (4) cooling. After the aqueous film-forming foam extinguishing agent is sprayed at high speed, a layer of foam and a water film are spread on the surface of the combustible liquid. The foam wets the surface of the combustible to absorb the heat generated in the combustion process, and then the heat is taken away by the evaporation of water.

For example, patent application with publication number CN111054009A discloses an aqueous film-forming foam fire extinguishing agent and a preparation method thereof, which comprises 8-20 wt% of combined hydrocarbon surfactant, 3-8 wt% of environmentally friendly fluorocarbon surfactant, 5-8 wt% of foam stabilizer, 20-50 wt% of antifreeze agent, 3-5 wt% of solubilizer and 20-40 wt% of water, but the performance of the foam fire extinguishing agent is still to be further improved.

Disclosure of Invention

The invention aims to provide a special water film-forming foam extinguishing agent for transformer oil fire and a preparation method thereof, which can more quickly generate a more stable foam layer and a more stable water film under the conditions of limited air suction amount and pressure.

The invention solves the technical problems through the following technical means:

a special water film-forming foam extinguishing agent for transformer oil fire is mainly prepared from the following raw materials in percentage by weight: 6-15% of fluorocarbon surfactant, 3-13% of hydrocarbon surfactant, 2-7% of solvent, 7-12% of cosolvent, 5-10% of foam stabilizer, 2-7% of corrosion inhibitor, 2-7% of antifreeze agent, 0.1-0.5% of chelating agent, 0.1-0.5% of thickening agent and 50-80% of water.

Has the advantages that: aiming at the defect that the water mist spray head cannot suck sufficient air to fully foam liquid, the water film forming foam preferably selects the optimal raw material and proportioning ratio range after the combination and comparison of various raw materials and different proportioning ratios.

Compared with the traditional aqueous film-forming foam extinguishing agent after being sprayed by a water mist spray head, the aqueous film-forming foam extinguishing agent has the advantages of more excellent performance, more stable foam, faster water film spreading speed, shorter fire extinguishing time and obvious use value.

The material used in the invention is simple and easy to obtain, has stable performance, extremely low pollution to environment, atmosphere and soil, extremely high biodegradation degree and is more environment-friendly.

Preferably, the fluorocarbon surfactant is a quaternary ammonium salt type cationic fluorocarbon surfactant.

Has the advantages that: the quaternary ammonium salt type cationic fluorocarbon surfactant can generate a layer of film on the surface of the liquid, improves the fluidity and the dispersibility of the liquid, has strong self-sealing capability, and is cheap and easy to obtain.

Preferably, the type of the quaternary ammonium salt type cationic fluorocarbon surfactant is intechem-01, intechem-02 or intechem-04.

Preferably, the hydrocarbon surfactant is sodium lauryl sulfate or sodium alpha-alkenyl sulfonate.

Has the beneficial effects that: the lauryl sodium sulfate has fixed hydrophilic and lipophilic groups, can form a monomolecular layer on the surface of a liquid, can be directionally arranged on the surface of a solution, and can remarkably reduce the interfacial tension between two liquids so as to remarkably reduce the surface tension.

Preferably, the solvent is diethylene glycol butyl ether.

Preferably, the cosolvent is 2-methyl-2, 4-pentanediol.

Preferably, the corrosion inhibitor is octyl-beta-D-glucopyranoside.

Preferably, the foam stabilizer is dibutyl sulfate.

Preferably, the antifreeze agent is ethylene glycol.

Preferably, the chelating agent is disodium edetate.

Preferably, the thickening agent is gelatin.

A method for preparing the special water film-forming foam extinguishing agent for transformer oil fire comprises the following steps:

s1, pre-adding water, a solvent and an anticorrosive agent: weighing water, a solvent and an anticorrosive agent according to the mass fraction ratio, adding the water, the solvent and the anticorrosive agent into a reaction kettle, and fully stirring the mixture at a stirring speed of 400-550r/min to completely dissolve the mixture;

s2, adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer: weighing and adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer into a reaction kettle according to the mass fraction ratio, heating, and fully stirring at the stirring speed of 400-550 r/min;

s3, adding an antifreeze agent, a chelating agent and a thickening agent: after the components in the step S2 are completely dissolved, weighing the components according to the mass fraction ratio, adding an antifreeze agent, a chelating agent and a thickening agent into the reaction kettle, and continuously and fully stirring the components at the stirring speed of 400-550 r/min;

s4, standing and filtering: and standing the solvent, and filtering after the foam is dissipated to obtain the water film-forming foam extinguishing agent special for transformer oil fire.

Has the advantages that: the preparation method is simple, the raw materials are simple and easy to obtain, and compared with the traditional aqueous film-forming foam extinguishing agent after being sprayed by a water mist spray head, the prepared aqueous film-forming foam extinguishing agent has the advantages of more excellent performance, more stable foam, faster water film spreading speed, shorter fire extinguishing time and obvious use value. The preparation process tests show that if the rotating speed is lower than 400r/min, the water-film-forming foam extinguishing agent insoluble raw material is difficult to dissolve in water and is fully mixed with other raw materials; if the rotating speed is more than 550r/min, the raw materials in the uniformly mixed aqueous film-forming foam extinguishing agent solution are layered under the action of centrifugal force, so that the mixing is not uniform, and the aqueous film-forming foam extinguishing agent is foamed in advance, so that the foaming performance of the product in the actual use process is influenced.

The invention has the advantages that: aiming at the defect that the water mist spray head cannot suck sufficient air to enable the foam concentrate to be fully foamed, the water film forming foam optimally selects the optimal raw material and proportioning ratio range after the combination and comparison of various raw materials and different proportioning ratios.

Compared with the traditional aqueous film-forming foam extinguishing agent after being sprayed by a water mist spray head, the aqueous film-forming foam extinguishing agent has the advantages of more excellent performance, more stable foam, faster water film spreading speed, shorter fire extinguishing time and obvious use value.

The material used in the invention is simple and easy to obtain, has stable performance, extremely low pollution to environment, atmosphere and soil, extremely high biodegradation degree and is more environment-friendly.

The preparation method is simple, the raw materials are simple and easy to obtain, and compared with the traditional aqueous film-forming foam extinguishing agent after being sprayed by a water mist spray head, the prepared aqueous film-forming foam extinguishing agent has the advantages of more excellent performance, more stable foam, faster water film spreading speed, shorter fire extinguishing time and obvious use value. The preparation process tests show that if the rotating speed is lower than 400r/min, the water-film-forming foam extinguishing agent insoluble raw material is difficult to dissolve in water and is fully mixed with other raw materials; if the rotating speed is more than 550r/min, the raw materials in the uniformly mixed aqueous film-forming foam extinguishing agent solution are layered under the action of centrifugal force, so that the mixing is not uniform, and the aqueous film-forming foam extinguishing agent is foamed in advance, so that the foaming performance of the product in the actual use process is influenced.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Test materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The specific techniques or conditions not specified in the examples can be performed according to the techniques or conditions described in the literature in the field or according to the product specification.

The invention aims at foam spraying and carries out a comparative experiment on the material and the mixing ratio. The material and the proportion are mixed according to the following table 1:

table 1 shows the range of the mixture ratio of each raw material in the aqueous film-forming foam extinguishing agent

By optimizing the examples, the ratio of the raw materials of the aqueous film-forming foam fire extinguishing agent is shown in table 2:

table 2 shows the preferred ranges of the respective raw materials of the aqueous film-forming foam fire extinguishing agent

Wherein the quaternary ammonium salt type cationic fluorocarbon surfactant is intechem-01, intechem-02 or intechem-04; the hydrocarbon surfactant is sodium dodecyl sulfate or alpha-sodium alkenyl sulfonate; the solvent is diethylene glycol butyl ether; the cosolvent is 2-methyl-2, 4-pentanediol; the corrosion inhibitor is octyl-beta-D-glucopyranoside; the foam stabilizer is dibutyl sulfate; the antifreeze agent is ethylene glycol; the chelating agent is disodium ethylene diamine tetraacetate; the thickener is gelatin.

The invention discloses a preparation method of a special water film-forming foam extinguishing agent for transformer oil fire, which comprises the following steps: mixing, stirring, heating and dissolving water, a solvent and an anticorrosive agent, adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer, stopping heating after dissolving, adding an antifreeze agent, a chelating agent and a thickening agent, continuing stirring, standing until foam is dissipated, and filtering to obtain the special water film-forming foam extinguishing agent for transformer oil fire.

The implementation nozzle of the aqueous film-forming foam extinguishing agent is a water mist nozzle, the water mist nozzle cannot suck enough air to fully foam the foam extinguishing agent, but the extinguishing agent can more quickly generate a more stable foam layer and a water film under the condition of limited air suction amount and pressure.

The foam spray head is selected according to the oil immersed power transformer:

1. when the rated capacity of the single group of transformers is more than 600MV & A, a foam fire pump is adopted to convey foam mixed liquid through a proportional mixing device and spray foam through a centrifugal atomization type water mist nozzle;

2. when the rated capacity of the single group of transformers is not more than 600MV & A, the compressed nitrogen drives the foam liquid in the storage tank to spray foam through a centrifugal atomization type water mist nozzle.

Aiming at the using conditions of the water spray nozzle, the invention compounds the preferable quaternary ammonium salt type cationic fluorocarbon surfactants intechem-01, intechem-02 and intechem-04 with the hydrocarbon surfactants sodium dodecyl sulfate and alpha-alkenyl sodium sulfonate, and the influence of different compound systems on the fire extinguishing performance is analyzed through experimental tests to obtain the optimal surfactant combination.

Example 1

The 6 groups of surfactants are obtained by compounding and combining 10 percent of quaternary ammonium salt type cationic fluorocarbon surfactant intechem-01 with 5 percent, 8 percent and 10 percent of hydrocarbon surfactant sodium dodecyl sulfate, 5 percent, 8 percent and 10 percent of hydrocarbon surfactant alpha-alkenyl sodium sulfonate respectively. Water, solvent, antifreeze agent, corrosion inhibitor, cosolvent, foam stabilizer, chelating agent and thickening agent are finely adjusted according to the optimal proportion.

The specific ratio is shown in table 3, for example:

table 3 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, a solvent and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotating speed of 500r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, dibutyl sulfate, intechem-01 type quaternary ammonium salt type cationic fluorocarbon surfactant and sodium dodecyl sulfate or alpha-alkenyl sodium sulfonate with different concentrations, stirring at the rotating speed of 500r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuing stirring at the rotating speed of 500r/min by using the magnetic stirrer for more than 1.5 hours. In the stirring process and the solution preparation process, a large amount of foam is generated, so that the solution needs to be kept stand for 24 hours, and after the foam is dissipated, a finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent of the example 1.

Example 2

The 6 groups of surfactants are obtained by compounding and combining 10 percent of quaternary ammonium salt type cationic fluorocarbon surfactant intechem-02 with 5 percent, 8 percent and 10 percent of hydrocarbon surfactant sodium dodecyl sulfate, 5 percent, 8 percent and 10 percent of hydrocarbon surfactant alpha-alkenyl sodium sulfonate respectively. Water, solvent, antifreeze agent, corrosion inhibitor, cosolvent, foam stabilizer, chelating agent and thickening agent are finely adjusted according to the optimal proportion.

The specific ratio is shown in table 4, for example:

table 4 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, a solvent and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotating speed of 500r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, dibutyl sulfate, intechem-02 type quaternary ammonium salt type cationic fluorocarbon surfactant and sodium dodecyl sulfate or alpha-alkenyl sodium sulfonate with different concentrations, stirring at the rotating speed of 500r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuing stirring for more than 1.5 hours at the rotating speed of 500r/min by using the magnetic stirrer. In the stirring process and the solution preparation process, a large amount of foam is generated, so that the solution needs to be kept stand for 24 hours, and after the foam is dissipated, a finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent of the example 2.

Example 3

The 6 groups of surfactants are obtained by compounding and combining 10% of quaternary ammonium salt type cationic fluorocarbon surfactant intechem-04 with 5%, 8%, 10% of hydrocarbon surfactant sodium dodecyl sulfate, 5%, 8%, 10% of hydrocarbon surfactant alpha-alkenyl sodium sulfonate respectively. Water, solvent, antifreeze agent, anticorrosive agent, cosolvent, foam stabilizer, chelating agent and thickening agent are finely adjusted according to the optimal proportion.

The specific ratio is shown in table 5, for example:

table 5 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, a solvent and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotating speed of 500r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, dibutyl sulfate, intechem-04 type quaternary ammonium salt type cationic fluorocarbon surfactant and sodium dodecyl sulfate or alpha-alkenyl sodium sulfonate with different concentrations, stirring at the rotating speed of 500r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuing stirring for more than 1.5 hours at the rotating speed of 500r/min by using the magnetic stirrer. In the stirring process and the solution preparation process, a large amount of foam is generated, so that the mixture needs to be kept stand for 24 hours, and after the foam is dissipated, the finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent in the example 3.

Example 4

The water film-forming foam extinguishing agent special for transformer oil fire is prepared from the following raw materials in parts by weight as shown in Table 6:

table 6 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, a solvent and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotation speed of 400r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, an intechem-04 type quaternary ammonium salt type cationic fluorocarbon surfactant, sodium dodecyl sulfate and dibutyl sulfate, stirring at the rotation speed of 400r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuing stirring at the rotation speed of 400r/min by using the magnetic stirrer for more than 1.5 hours. In the stirring process and the solution preparation process, a large amount of foam is generated, so that the solution needs to be kept stand for 24 hours, and after the foam is dissipated, the finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent of the example 4.

Example 5

The water film-forming foam extinguishing agent special for transformer oil fire is prepared from the following raw materials in parts by weight as shown in Table 7:

table 7 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, diethylene glycol monobutyl ether and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotating speed of 450r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, an intechem-04 type quaternary ammonium salt type cationic fluorocarbon surfactant, sodium dodecyl sulfate and dibutyl sulfate, stirring at the rotating speed of 450r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuously stirring for more than 1.5 hours at the rotating speed of 450r/min by using the magnetic stirrer. During the stirring process and the solution preparation process, a large amount of foam is generated, so that the solution needs to be kept stand for 24 hours, and after the foam is dissipated, the finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent of example 5.

Example 6

The water film-forming foam extinguishing agent special for transformer oil fire comprises the following raw materials in parts by weight as shown in Table 8:

table 8 shows the proportions of the respective raw materials in this example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, putting water, diethylene glycol monobutyl ether and octyl-beta-D-glucopyranoside into a constant temperature water bath kettle, setting the temperature to 90 ℃, stirring at the rotating speed of 550r/min by using a magnetic stirrer until the mixture is completely dissolved, then adding 2-methyl-2, 4-pentanediol, an intechem-04 type quaternary ammonium salt type cationic fluorocarbon surfactant, sodium dodecyl sulfate and dibutyl sulfate, stirring at the rotating speed of 550r/min by using the magnetic stirrer until the mixture is fully dissolved, stopping heating, then adding ethylene glycol, disodium ethylene diamine tetraacetate and gelatin, and continuously stirring for more than 1.5 hours at the rotating speed of 550r/min by using the magnetic stirrer. In the stirring process and the solution preparation process, a large amount of foam is generated, so that the solution needs to be kept stand for 24 hours, and after the foam is dissipated, a finished product is filtered and extracted to obtain the water film-forming foam extinguishing agent of the example 6.

Comparative example 1

According to the method described in patent application example 1 with publication number CN111054009A, the water ratio is adjusted to make the total mass percent of the water to be 100%, and the water film-forming foam extinguishing agent is prepared.

Table 9 shows the proportions of the respective raw materials in this comparative example

The preparation method of the aqueous film-forming foam extinguishing agent of the embodiment comprises the following steps: firstly, 15 percent of combined hydrocarbon surfactant (10 percent of sodium lauryl sulfate and 5 percent of octyl sodium sulfonate) is fully dissolved by adding pure water to form a component A; then adding 6 percent of environment-friendly fluorocarbon surfactant into the component A to be mixed to form a component B; and then, uniformly mixing 7% of foam stabilizer, 33.5% of antifreeze and 3.5% of solubilizer to form a component C, slowly adding the component C into the component B, uniformly mixing the component C and the component B, introducing the mixture into a stirring tank, fully stirring to form a reaction solution, adjusting the pH value of the reaction solution to be 6.8-7.2, controlling the temperature to be about 40 ℃, standing for defoaming, and obtaining the water film-forming foam extinguishing agent of the comparative example 1.

The spreading performance, the foaming performance and the fire extinguishing performance of the aqueous film forming foam fire extinguishing agent prepared in each example were measured under the conditions of use of the water mist spray head, and the results are shown in table 10.

TABLE 10 Performance test Table for aqueous film-forming foam fire extinguishing agents in examples

As can be seen from Table 10, the preferable compound system composed of the surfactants has the best spreading performance, foaming performance and fire extinguishing performance in the intechem-04/sodium dodecyl sulfate compound system under the using condition of the water mist spray head. With the increase of the content of the lauryl sodium sulfate, the spreading speed of the aqueous film-forming foam extinguishing agent prepared by the intechem-04/lauryl sodium sulfate compound system is stably increased, the foaming times reach the standard of low-expansion foam solution, and the fire extinguishing time is effectively shortened. Therefore, the quaternary ammonium salt type cationic fluorocarbon surfactant used in the invention is intechem-04, and the hydrocarbon surfactant is sodium dodecyl sulfate.

The fluorocarbon surfactant in the aqueous film-forming foam extinguishing agent is the most important type of surfactants in a plurality of surfactants and has the characteristics of three highs and two phobics: high surface activity, high heat stability, high chemical stability, and hydrophobicity and oleophobicity. Because the affinity of the fluorocarbon chains to water is small, the surfactant is greatly gathered on the surface of the solution to form stronger surface adsorption, and the saturated adsorption capacity is increased, so that the energy required by the surfactant molecules to migrate from the inside of the solution to the surface is reduced, and the surface tension is reduced.

The fluorocarbon surfactant has the advantages of excellent wettability, solubilization, antistatic property, thermal stability and the like, good compatibility, antistatic property and the like. The quaternary ammonium salt type cationic fluorocarbon surfactant has the advantages of heat resistance, hard water resistance, excellent foamability and dispersibility. The anionic surfactant sodium dodecyl sulfate has excellent foaming power, low surface tension and biodegradability of more than 90%, can form a layer of film on the surface of liquid, improves the fluidity and the dispersibility of the liquid, has strong self-sealing capability and can quickly extinguish fire. The cationic surfactant has good coordination with anionic and nonionic surfactants, good chemical stability, heat resistance, light resistance, strong acid and alkali resistance. The fluorocarbon surfactant is applied by combining with the hydrocarbon surfactant, has excellent synergistic effect, not only can reduce the surface tension of the solution, but also can reduce the water-oil interfacial tension.

Diethylene glycol monobutyl ether has higher boiling point and lower volatilization speed, is soluble in water and alcohol and is a stable solvent. 2-methyl-2, 4-pentanediol is a colorless, tasteless and toxic high-grade organic solvent which is completely miscible with water and has strong solubility. octyl-beta-D-glucopyranoside is one of novel nonionic surfactants APG, has the characteristics of common nonionic and anionic surfactants, low surface tension, rich, fine and stable generated foam, strong alkali and strong acid resistance and strong wetting power, can be compounded with various surfactants, has obvious synergistic effect, has the unique properties of no toxicity, no harm, no stimulation, quick biodegradation, complete sterilization and the like, and is a green surfactant with comprehensive performance. Disodium edetate has wide coordination performance and can form stable chelate with almost all metal ions. Gelatin is a macromolecular hydrophilic colloid, which increases the viscosity of the solution.

The dibutyl sulfate is used as a foam stabilizer and an anti-burning agent, and has the advantages of low price, good foam stabilizing effect, good anti-burning performance and wide application; ethylene glycol is selected as an antifreeze agent and a cosolvent, and the ethylene glycol as the most main antifreeze agent has the characteristics of good chemical property, low price, low viscosity and the like, and can effectively reduce the freezing point of the fire extinguishing agent. The glycol is easy to dissolve in water and can be mutually dissolved with other organic matters, so that the solubility of the surfactant is improved.

The surfactant, the solvent and the like have good foaming capacity, greatly improve the stability of foam under the action of the foam stabilizer, and further improve the fire extinguishing effect of the aqueous film-forming foam extinguishing agent.

The invention discloses a preparation method of a special water film-forming foam extinguishing agent for transformer oil fire, which comprises the following steps: mixing water, a solvent and an anticorrosive agent, stirring, heating and dissolving, adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer, stopping heating after dissolving, adding an antifreeze agent, a chelating agent and a thickening agent, continuing stirring, standing until foam is dissipated, and filtering to obtain the special water film-forming foam extinguishing agent for transformer oil fire. The performance indexes of the aqueous film forming fire foam prepared in examples 4 to 6 and comparative example 1 were measured under the conditions of use of the water mist head, and the results are shown in Table 11.

TABLE 11 table for examining the properties of examples 4 to 7

According to Table 11, it can be found that the aqueous film-forming foam fire extinguishing agent of the invention has all the properties in accordance with GB15308-2006 foam fire extinguishing agent in the range of the preferred raw material mixture ratio. Along with the increase of the surfactant and the improvement of the stirring speed, the surface tension of a water film and a foam concentrate formed by the prepared water film-forming foam extinguishing agent through the water mist spray nozzle on the combustible liquid surface is obviously reduced, and meanwhile, the spreading speed of the water film and the foam layer is also obviously improved, so that the high-efficiency and rapid fire extinguishing work is realized. Under the using condition of a water mist spray head, the performance parameters detected by the aqueous film-forming foam extinguishing agent prepared by the proportioning and preparation method provided by the patent application with the publication number of CN111054009A are inferior to those of the aqueous film-forming foam extinguishing agent in terms of foaming times, fire extinguishing time and spreading rate.

Therefore, compared with the traditional aqueous film-forming foam fire extinguishing agent, the aqueous film-forming foam fire extinguishing agent special for transformer oil fire can effectively reduce the surface tension, has considerable foaming times, stable foam layers, quick fire extinguishing time and spreading time, and can spray foam liquid which is green and environment-friendly and can be efficiently biodegraded.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. The special water film-forming foam extinguishing agent for transformer oil fire is characterized in that: the material is mainly prepared from the following raw materials in percentage by weight: 6-15% of fluorocarbon surfactant, 3-13% of hydrocarbon surfactant, 2-7% of solvent, 7-12% of cosolvent, 5-10% of foam stabilizer, 2-7% of anticorrosive agent, 2-7% of antifreeze agent, 0.1-0.5% of chelating agent, 0.1-0.5% of thickening agent and 50-80% of water.

2. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the fluorocarbon surfactant is a quaternary ammonium salt type cationic fluorocarbon surfactant.

3. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the quaternary ammonium salt type cationic fluorocarbon surfactant is intechem-01, intechem-02 or intechem-04.

4. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the hydrocarbon surfactant is sodium dodecyl sulfate or alpha-sodium alkenyl sulfonate.

5. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the solvent is diethylene glycol butyl ether, and the cosolvent is 2-methyl-2, 4-pentanediol.

6. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the anticorrosive agent is octyl-beta-D-glucopyranoside.

7. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the foam stabilizer is dibutyl sulfate.

8. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the antifreeze agent is ethylene glycol, and the chelating agent is disodium ethylene diamine tetraacetate.

9. The special aqueous film-forming foam extinguishing agent for transformer oil fire according to claim 1, characterized in that: the thickener is gelatin.

10. The preparation method of the special aqueous film-forming foam extinguishing agent for transformer oil fire according to any one of claims 1 to 9, characterized by comprising the following steps: the method comprises the following steps:

s1, pre-adding water, a solvent and an anticorrosive agent: weighing water, a solvent and an anticorrosive agent according to the mass fraction ratio, adding the water, the solvent and the anticorrosive agent into a reaction kettle, and fully stirring the mixture at a stirring speed of 400-550r/min to completely dissolve the mixture;

s2, adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer: weighing and adding a cosolvent, a fluorocarbon surfactant, a hydrocarbon surfactant and a foam stabilizer into a reaction kettle according to the mass fraction ratio, heating, and fully stirring at the stirring speed of 400-550 r/min;

s3, adding an antifreeze agent, a chelating agent and a thickening agent: after the components in the step S2 are completely dissolved, weighing the components according to the mass fraction ratio, adding an antifreeze agent, a chelating agent and a thickening agent into the reaction kettle, and continuously and fully stirring the components at the stirring speed of 400-550 r/min;

s4, standing and filtering: and standing the solvent, and filtering after the foam is dissipated to obtain the special water film-forming foam extinguishing agent for transformer oil fire.