CN114768163A

CN114768163A - Aerosol fire extinguishing agent

Info

Publication number: CN114768163A
Application number: CN202111655915.2A
Authority: CN
Inventors: 胡伟东; 米秋林
Original assignee: Shanghai Shangge Information Technology Co ltd
Current assignee: Shanghai Shangge Information Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-07-22

Abstract

The invention relates to the technical field of fire extinguishing agents, in particular to an aerosol fire extinguishing agent, which comprises a hexahydric alcohol combustible adhesive with a melting point lower than 200 ℃ and an oxidant of metal nitrate, and also comprises a gas generating agent and a catalyst, wherein the weight percentages of the components are as follows: hexahydric alcohol combustible binder: 0.29 percent; gas generating agent: 0.2 percent; catalyst: 0.05 percent; the balance of oxidant can improve the fire extinguishing efficiency of the AOS and reduce the temperature of aerosol jet; the gas generating agent is used in combination with a catalyst to ensure stable combustion, the calculated combustion rate of the composition is 1.9-2.2mm/s, and the increase in the amount of gas generating agent in the AOS results in a decrease in the combustion rate and a decrease in flammability.

Description

Aerosol fire extinguishing agent

Technical Field

The invention relates to the technical field of fire extinguishing agents, in particular to an aerosol fire extinguishing agent.

Background

A total flooding aerosol fire suppression agent comprising a solid fuel aerosol generating composition (AOS).

Most aerosol-generating compositions have relatively high temperature combustion products, i.e. the temperature of the fire-extinguishing aerosol released at acceptable fire-extinguishing performance is about 1500 ℃, and close to the maximum allowable levels of toxic gas combustion products (e.g. carbon monoxide (CO), nitrogen oxides (NO, NO2) and ammonia (NH 3)).

These parameters are mainly due to the use of high heat fuels and combustible binders in AOS from various hydrocarbons (phenol formaldehyde, epoxy, polyester resins, etc.) and industrial carbons (coal, soot). Table 1 shows the ingredients in a conventional AOS.

AOS, when burned in air with a variety of hydrocarbon high calorie fuels or combustible binders, emit intense rays of light with hot gases and incandescent particles, which have significant thermal effects on the environment.

This makes it difficult for aerosol fire extinguishing devices to use AOS without coolant in sealed and relatively sealed spaces, and cannot be used in portable fire extinguishers intended for outdoor spaces to use AOS for extinguishing objects, such as clothing on a person.

Hexahydric alcohols and mixtures thereof have long been known in the fire extinguishing technology and are mainly used as emulsifiers for producing high-power foams, and the hexahydric alcohol aerosol products are environment-friendly, low-temperature and low-flame.

Ukrainia patent: UA7773 discloses an aerosol-forming solid fuel composition for fire extinguishing comprising wood flour, potassium nitrate, potassium perchlorate, hexahydric alcohol, dicyandiamide or diphenylamine in the following weight percentages: 0.625 percent of potassium perchlorate; potassium nitrate 0.794%; 0.61 percent of hexahydric alcohol; dicyandiamide or diphenylamine 0.5%; the balance being wood flour.

However, the above patents have the following disadvantages:

1. too high a dicyandiamide content destroys the balance of solid and gaseous components of the aerosol composite, thereby lowering the fire extinguishing efficiency and, in addition, deteriorating the combustion conditions of the composition.

2. Years of experience have shown that the inclusion of potassium perchlorate in compositions containing hexahydric alcohol formulations is undesirable because the chloride salt slows its ability to crystallize. The composition may not harden for several months and has cold flow properties. In addition, potassium perchlorate increases the risk of friction sensitivity, requires special storage conditions and is limited in use.

3. The use of wood flour as a constituent component increases the heating value of the AOS (i.e., increases the temperature of the aerosol mixture) and increases the content of harmful substances (mainly carcinogens) in the aerosol cloud gas.

4. Replacing dicyandiamide with the indicated amount of diphenylamine results in a significant reduction in the operating temperature of the AOS (melting point of diphenylamine is 56 ℃).

5. The composition does not contain a catalyst, so that stable combustion can be guaranteed at an optimal speed and with the minimum content of carbon monoxide;

disclosure of Invention

The invention aims to solve the defects of the prior art and provides an aerosol fire extinguishing agent, which comprises a hexahydric alcohol combustible binder with a melting point lower than 200 ℃ and an oxidant of metal nitrate, a gas generating agent and a catalyst, and the weight percentages of the components are as follows: hexahydric alcohol combustible binder: 0.29 percent; gas generating agent: 0.2 percent; catalyst: 0.05 percent; the balance being an oxidant.

The invention also has the following preferable technical scheme:

1. the gas generating agent comprises dicyandiamide or/and melamine and/or other thermal decomposition products.

2. The gas generant contains an organometallic salt.

3. A gas generant comprising urotropin and/or urea.

Compared with the prior art, the invention has the advantages that:

1. the process of preparation is safer and conventional ingredients need to be crushed, mixed in the right proportions and pressed, and in order to obtain compositions of the stated properties the ingredients must be ground to a size of 20-50 microns, in which case the pressing process is dangerous even if the inert ingredients such as dicyandiamide explode in the airborne dust cloud, not to mention the fact that crushed potassium perchlorate is also present, since the pressing pressure of the dry mixture is not less than 2500kg/cm2 at a binder melting temperature not less than 200 ℃.

2. The cost of manufacture is lower and conventional ingredients can be prepared by dissolving, dissolving in water, evaporating the solution to the desired standard, and then pouring into molds for drying. This technique is safer than crushing, but requires special equipment: vacuum molds, drying ovens, high power ventilation equipment and larger production sites, which require high power electricity and longer production times (more than 30 hours for drying time only).

3. The present invention solves both of the above problems while improving the fire extinguishing efficiency of the AOS (less than 0.030 g/m3) and reducing the temperature of the aerosol jet.

4. The gas generating agent is used in combination with a catalyst to ensure stable combustion, the calculated rate of combustion of the composition is 1.9-2.2mm/s, and the increase in the amount of gas generating agent in the AOS reduces the rate of combustion and the flammability.

Detailed Description

The present invention is further described below, and the structure and principle of the present invention will be apparent to those skilled in the art. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

The invention relates to an aerosol fire extinguishing agent, which comprises hexahydric alcohol combustible adhesive with a melting point lower than 200 ℃ and an oxidant of metal nitrate, and also comprises a gas generating agent and a catalyst, wherein the weight percentages of the components are as follows: hexahydric alcohol combustible binder: 0.29 percent; gas generating agent: 0.2 percent; catalyst: 0.05 percent; the balance being an oxidant.

Referring to table 2, the UA7773 patent discloses an aerosol-forming solid fuel composition for fire extinguishing comprising wood flour, potassium nitrate, potassium perchlorate, hexahydric alcohol, dicyandiamide or diphenylamine in the following weight percentages: 0.625 percent of potassium perchlorate; potassium nitrate 0.794%; 0.61 percent of hexahydric alcohol; dicyandiamide or diphenylamine 0.5%; the balance being wood flour. The composition has the following disadvantages:

2. Years of experience have shown that the inclusion of potassium perchlorate in compositions in formulations containing hexahydric alcohols is undesirable because chloride salts slow down their ability to crystallize. The composition may not harden for several months and has cold flow properties. In addition, potassium perchlorate increases the risk of friction sensitivity, requires special storage conditions and is limited in use.

5. The absence of catalyst in the composition ensures stable combustion at optimum rates and with minimum carbon monoxide content.

Aiming at the defects, the components of the invention are optimized as follows:

1. the content of dicyandiamide is reduced from 0.5% to 0.2%.

2. Removing potassium perchlorate.

3. Removing wood powder component.

4. There is no diphenylamine in the composition.

5. The component (A) contains iron oxide as a catalyst.

In a preferred embodiment: hexahydric alcohols having a melting point of about 100 ℃ are used as combustible binders.

In a next preferred embodiment, a mixture of hexahydric alcohols having a melting point of less than 200 ℃ is used as combustible binder.

In a further preferred embodiment, dicyandiamide or/and melamine (melamine) and/or thermal decomposition products thereof are used as gas generating agent.

In a next preferred embodiment, urea or/and urotropin is used as gas generating agent.

In a next preferred embodiment, an organometallic salt is used as the gas generating agent.

In the next preferred embodiment, the listed mixture components are used as gas generants.

Particular attention should be paid to the fire extinguishing effect of the described six-membered alcohol low flame AOS in coolant-free portable fire extinguishers for extinguishing the burning of outdoor standards (e.g., clothing on a person).

The aerosol jet temperature of this type of extinguisher does not exceed 50 ℃ at a distance of 20 cm from the outlet.

The AOS can be used as a driving agent for dry powder and liquid fire extinguishing systems and can enhance the fire extinguishing effect.

As mentioned earlier, the production technique of the hexahydric alcohol low flame AOS is simple and safe. Melting of the composition ingredients is carried out in a conventional reactor with an agitator at a temperature of less than 120 c, i.e. well below the combustion temperature of the composition ingredients.

The composition is then poured into moulds or cartridges and allowed to cool (40-60 minutes) before being ready for use. This technique, which utilizes the uniform distribution of the comminuted components in the combustible binder melt, ensures that the particles participating in the reaction are at a distance from the molecule. This situation, along with the carefully selected chemical components, provides unique performance characteristics for the AOS proposed by the authors.

If desired, the AOS may also be manufactured using conventional techniques: extrusion, roll forming, dead-die forming, continuous forming, and the like, but in this case, it is considered that the performance characteristics of the AOS are degraded.

The effectiveness of the AOS agent family depends on the size of the distance between the particles and molecules involved in the reaction and a proper formulation is matched.

TABLE 1

TABLE 2

Claims

1. An aerosol fire extinguishing agent, which comprises hexahydric alcohol combustible binder with a melting point lower than 200 ℃ and an oxidant of metal nitrate, and is characterized by further comprising a gas generating agent and a catalyst, wherein the weight percentages of the components are as follows:

hexahydric alcohol combustible binder: 0.29 percent;

gas generating agent: 0.2 percent;

catalyst: 0.05 percent;

the balance being an oxidant.

2. An aerosol fire extinguishing agent according to claim 1, wherein the gas generating agent comprises dicyandiamide or/and melamine and/or other thermal decomposition products.

3. An aerosol fire extinguishing agent according to claim 1, wherein the gas generating agent comprises an organometallic salt.

4. An aerosol fire extinguishing agent according to claim 1, wherein the gas generating agent comprises urotropin and/or urea.