TWI468196B - Low temperature flameless aerosol producing fire extinguishing composition and production method thereof - Google Patents

Description

Low-temperature flameless gas-forming fire extinguishing composition and manufacturing method thereof

The present invention relates generally to fire suppression, and more particularly to a fire extinguishing gas that can be applied in an enclosed space.

Fire-extinguishing glues are usually by-products of the combustion of specially formulated materials containing potassium nitrate and/or perchlorate as oxidants and supplies for their primary fire-extinguishing agents. When a plasticized and non-plasticized polymer is used as a binding fuel, it can be transformed into a viscous or elastic state under the influence of thermal and/or mechanical properties. Among the currently known and widely used bonded fuels, phenol-formaldehyde and epoxy resins, polyvinyl butyral, cellulose ether, rubber and the like are particularly noteworthy among them.

The main component of the fire-extinguishing glue is a superfine (0.5~5μm) potassium compound formed by the chemical reaction of the oxidant with the fuel and dispersed as a gaseous reaction product.

The extinguishing effect of this gas gel depends on the amount of the potassium compound particles and the individual size, which itself is further related to the temperature and the degree of completion of the chemical reaction between the oxidant and the fuel. Furthermore, the combustion temperature of the above composition is directly related to the temperature at which the bonded fuel is burned. D.I.Mendeleev has calculated the following calculation formula for the combustion heat of solid and liquid fuels: Q=81C+300H-26(O-S)-6(9H+W)

Among them, C, H, O, S and W are the working quality of the fuel, and its points Do not express carbon, hydrogen, oxygen, sulfur and moisture in terms of mass percentage, while thermal energy is expressed in kcal/kg.

The calculation results of the combustion heat of various types of fuels and bonded fuels are shown in Table 1.

The heat of combustion of the bonded fuel determines the temperature of the gas gel it produces. In practice, this value cannot exceed certain critical points in determining the safety of the fire extinguisher in the environment.

In order to reduce the temperature of the fire extinguishing glue, the existing method is to add fire extinguishing cooling components such as ditsiandiamid, melema, melamine and other substances (patent RU 2095104, C1, 10.11.97), and/or ( Use of pellets in the manufacture of fire extinguishing gas generators Special cooling elements in the form of tubes, tubes, monoliths or other constituents (see patent RU 2064305, C1, 27.07.96). Compared with the uncooled gas glue, the above two methods will reduce the fire extinguishing effect of half of the gas gel, and at the same time increase the toxicity of the produced gas gel which cannot be oxidized in the air due to the generation of carbon monoxide. Material content.

The gas-forming compound for fire fighting is an important breakthrough (see patent RU 2160619, class A62D 1/06, from 20.12.2000), which contains 65-75% potassium nitrate and 0-5% bonded fuel. 10-20% of the ditsiandiamid and other additional fuels that make up the remaining proportions, which can be burned with potassium nitrate. Simply put, it uses another preset to counteract super-hot particle fuels (such as starch, hydroquinone, phenolphthalein, decyl salicylamine or the like) to replace traditional bonded fuels (such as phenol formaldehyde resins). Or iditol). However, in addition to the high temperature gas gel, this method is also limited in its use.

In another known composition and method of manufacture, the oxidant is subjected to a hazardous and labor intensive mashing process in which the bonded fuel is dissolved in a toxic dichloromethane solution to ensure that the constituents are in the mixture. Can be evenly dispersed (see patent RU 2185865, class A62D 1/00, 27.07.2002).

Another fairly relevant manufacturing method involves mixing the constituents in a 30-35% polyethylene aqueous dispersion (patent RU 2005517, class A62D 1/00, 15.01.94), but in this case, The oxidant cannot be sufficiently comminuted and remains suspended in the water.

Therefore, the industry today needs an answer to the limitations described above.

The present invention discloses a composition and a method of manufacturing the same that are safe and do not require intensive labor, and at the same time allow the ingredients to be completely mixed.

In this paper, a substance is proposed in which a binding fuel exhibits low combustion heat and a relatively high oxygen concentration (high alpha oxygen balance), converting its combustion process into a flameless mode. Extensive fire-extinguishing properties and acceptable levels of carbon monoxide. In addition, due to the use of cellulose paper, another technical result of the disclosed method is to increase the variety of material processing methods of the gas-gel generating material, specifically, such as roll forging, flat roll Technology such as rolling or extrusion.

The solution to the foregoing problems and the method of achieving the technical results required by the present invention are achieved by utilizing the provided gas-fired fire-extinguishing composition having low-temperature flameless properties and a method for producing the same.

The invention discloses a gas-gel-formed fire-extinguishing composition with low-temperature flameless property, which comprises potassium nitrate and a bonded fuel, characterized by having a cellulose fiber material, and the mass percentage thereof is 30-70%. Potassium nitrate, while the cellulose fiber material constitutes the remainder.

The composition of the present invention preferably contains paper stock or cotton material as its cellulose fiber material.

The composition of the present invention preferably contains water-soluble copper nitrate and/or iron (III) nitrate.

The method for producing a gas-gel-formed fire-extinguishing composition having low-temperature flameless properties disclosed in the present invention comprises immersing a cellulosic fiber material in a hot saturated aqueous solution of potassium nitrate, and then dehydrating it to 40-60%. The amount of water is then further dried with hot air to a moisture content of 1-2%.

In the preferred case, the material obtained above is preferably further molded into the size and shape desired by us.

Preferably, the present invention preferably forms the product of the present invention by winding the above-described material which has been subjected to forced hot air drying to a moisture content of 1-2% into a web having a desired size.

Preferably, the present invention is preferably formed by applying a hydroforming process at a pressure of from 30 to 150 MPa on a substrate heated to 90-95 ° C, followed by drying the product to a moisture content of 1-2%. The product of the invention.

In a preferred embodiment, the product of the present invention can be formed by collecting a "sock" formed of the material using a roll having a smooth or ribbed surface heated to 80-100 ° C. These socks are regularly cut from the tool and rolled into the diameters required by us.

The method disclosed in the present invention comprises adding copper nitrate and/or iron (III) nitrate as a combustion catalyst, and simultaneously immersing the cellulose fiber material in a potassium nitrate solution.

The method disclosed by the present invention further comprises a further water-repellent treatment by covering a paint film having a thickness of 50-80 microns over the dried and/or formed into a desired size and shape having a moisture content of 1-2%. On the product.

Preferably, the present invention preferably uses nitrocellulose (usually used in furniture varnishes) and epoxy lacquers as a water repellent to surface treat the product.

The composition of the present invention undergoes thermal decomposition of the cellulose during combustion to form a coal ash skeleton which activates the decomposition of potassium nitrate. fiber The thermal decomposition of the element consumes a considerable amount of heat energy, but since the heat of combustion is relatively small, the composition of the present invention does not generate a flame upon combustion, and the product after combustion is not particularly hot. This phenomenon represents a potential to significantly reduce and simplify the construction of fire extinguishing gas generators because we do not need to use bulky gas coolant.

The molecular structure of the cellulose in the composition of the present invention may have an oxygen content of up to 50% by mass, which may significantly increase the alpha oxygen balance of the composition to 0.7-0.9. This property reduces the toxic carbon monoxide in the combustion products to a reasonable extent. Combustion catalysts (such as water-soluble copper nitrate and ferric nitrate) can also be used in the composition to further promote the reduction of carbon monoxide.

In the present invention, the use of a catalyst increases the linear velocity of combustion of the composition by about 20-25%.

The fire test properties of the compositions disclosed herein were tested in a clean and fully sealed 9 liter vessel.

For this purpose, a gasoline-filled alcohol lamp is ignited in the container, followed by the introduction of "tablets" or twisted material in the form of a quantitative substance. The free burning time of the above alcohol lamp in the sealed container is about 3 minutes. If the substance is extinguished within 40-60 seconds after being ignited, the experimental results will be considered to be advantageous. In the present invention, the extinguishing concentration is defined as the result of dividing the starting weight of the above-mentioned sheet or fabric by the volume of the container.

The surface temperature of the test sample was measured using a thermocouple. The results of the estimation of the properties of the compositions proposed by the present invention are listed in Table 2.

Table II

As mentioned earlier, the extinguishing effect of the gas gel is related to the temperature and the degree of completion of the chemical reaction during combustion. The degree of completion of the chemical reaction also determines the degree of contamination of the gas gel, such as the concentration of the heat medium particles and carbon monoxide. The degree of completion of the chemical reaction in the mixture of solid materials is related to the contact surface of the particles. In other words, the smaller the smaller the reaction particles and the more uniform the composition, the more complete the chemical reaction is achieved while the other variables remain fixed. The higher the height. This is a very important technical point for making the gas-forming composition of the present invention.

In the manufacturing method disclosed in the present invention, the cellulose fiber material is combined with potassium nitrate by immersing the material in a hot saturated solution of potassium nitrate, and the method of absorbing potassium nitrate from the solution through the cellulose. The ingredients are evenly distributed to provide a safe manufacturing process for the compositions of the present invention.

The swelling treatment of the above cellulose fiber material in a hot saturated solution of potassium nitrate is carried out for 7-10 minutes, and finally preliminary dehydration treatment is carried out to a water content of 40-60%.

The cellulosic fibrous material described above is then further dewatered to a moisture content of 1-2%; for example, hot air is blown to a temperature of 95-105 degrees Celsius and entangled into a roll of the desired size.

Another technical result of the method disclosed in the present invention is to use a cellulosic material to increase the diversity of the gas-formed material processing method, specifically, it can use roll forging, flat rolling or extrusion molding, etc. Made in a way.

The above method can be used because the production of paper requires the grinding of lignocellulosic fibers into shorter, thinner fibers, but it has a higher degree of asymmetry (length versus cross-section) than the starting fibers. apart from In addition to the fiber splitting, the destruction and amorphization of the original structure will occur at the same time. This combination gives the surface layer a higher degree of plasticity. To create a tough paper web from moist and elastic pulp, the focus of its treatment is to change the relationship between its molecules, which can be achieved by removing moisture from the material to the intermolecular attraction between the cellulose chains. It is achieved by replacing the capillary force (surface tension). During the secondary swelling of cellulose in water, the intermolecular linkage of the cellulose chain is weakened, and the glass transition temperature is lowered and plasticity is obtained, that is, the ability to flow with a small force is applied (Pankov. SP Fiberous polymer) materials.M: Himiya, 1986.).

The moist heat cellulose paper after absorption of potassium nitrate is applied with a water pressure of 30 to 150 MPa using the heated substrate. The diameter and water content of the compressed piece are 10-35 mm and 8-10% of the mass, respectively. The piece is further dried with hot air to a moisture content of 1-2%.

The moist heat cellulose paper with potassium nitrate is plate rolled on a smooth (longitudinal) rib roll heated to 80-100 ° C. After collecting the "socks" from the auxiliary reel and reducing its moisture to 1-2%, the reel will stop rotating and the sock will be cut from the reel and wound into the desired diameter.

We can then use a specific lacquer to perform the final hydrophobic surface treatment of the composition of the invention with a dry film thickness of 50-80 microns.

While the invention has been described herein by way of example and the preferred embodiments thereof, it is understood that the invention is not limited thereto. On the contrary, the invention is intended to cover various modifications and equivalents of the embodiments of the present invention (as apparent to those skilled in the art). Therefore, the scope of the attached patent application scope should be interpreted to the broadest extent to cover All such corrections are similar to the configuration.

Claims (11)

A low temperature flameless gas gel-forming fire extinguishing composition comprising potassium nitrate, a bonded fuel and water-soluble copper nitrate and/or iron (III) nitrate as a combustion catalyst, wherein the composition has the following percentage by mass The potassium nitrate is 30% to 70%; and the water-soluble copper nitrate and/or iron (III) nitrate and the cellulose fiber material are the remaining portions. The composition according to claim 1, further comprising paper as the cellulose fiber material. The composition as recited in claim 1 further includes a cotton fabric as the cellulose fiber material. A method for producing a low temperature flameless gas gel-forming fire extinguishing composition according to claim 1, wherein the cellulose fiber material is immersed in potassium nitrate when the cellulose fiber material is swollen in a hot saturated aqueous solution Excess water is then removed from the solution to a moisture content of 40-60% and dried to a moisture content of 1-2%. The manufacturing method as described in claim 4, wherein the product from the composition is formed into a desired size and shape. The manufacturing method as recited in claim 5, wherein the product is formed by winding a sheet which has been previously dried by forced hot air into a 1-2% moisture content into a roll having a desired size. The manufacturing method as described in claim 5, wherein the water is formed by applying a pressure of 30 to 150 MPa (Mpa) using a substrate heated to 90-95 ° C, and then drying the product to 1 -2% The way the water content is shaped makes the product. The method of manufacture of claim 5, wherein the forming of the product is carried out by using a smooth or ribbed reel heated to 80-100 ° C and drying the material to a moisture content of 1-2%. A "sock" is made from the material which is periodically cut from the tool and then wound into a roll of the desired diameter. The production method as described in claim 4, wherein a combustion catalyst selected from copper nitrate and/or iron (III) nitrate is added during the saturation of the cellulose fiber material and potassium nitrate. The manufacturing method as described in claim 4, wherein after the product is dried and/or formed into a desired size and shape having a water content of 1-2%, the surface of the product is treated with a water repellent agent. For example, a lacquer with a dry film thickness of 50-80 microns is used. The manufacturing method as described in claim 10, wherein the lacquer used for the water-repellent treatment of the surface of the product comprises nitrocellulose and epoxy lacquer.