WO1997045166A1

WO1997045166A1 - Mineral-water suspension for use against fires

Info

Publication number: WO1997045166A1
Application number: PCT/RU1997/000127
Authority: WO
Inventors: Alexandr Ivanovich Gurov; Leonid Alexandrovich Odnovol; Alexandr Nikolaevich Sytnikov
Original assignee: Mezhdunarodny F0Nd Popechitelei Moskovskogo Gosudarstvennogo Aviatsionnogo Tekhnologicheskogo Universiteta Imeni K.E.Tsiolkovskogo
Priority date: 1996-05-24
Filing date: 1997-04-24
Publication date: 1997-12-04
Also published as: EP0903163A1; JP2000512517A; TR199802335T2; AU718475B2; CA2252760A1; CN1219137A; KR20000015945A; AU3050697A; EP0903163A4; BR9709343A; RU2098158C1

Abstract

The present invention relates to a mineral-water suspension for use against fires that can be used in extinguishing or preventing fires of various types and forces. This suspension comprises liquid glass, clay and water, wherein the liquid glass is present in a weight proportion relative to the clay ranging from 1:1 to 1:10, respectively.

Description

FIRE MINERAL WATER SUSPENSION

Technical field

The present invention relates to materials for extinguishing and preventing fires, and more particularly to a fire-resistant mineral water suspension.

State of the art

Widely known are the systems of state and public events held with the aim of preventing fires, limiting the spread of fires and successfully extinguishing fires of various types and capacities. An integral part of this system is the development of new tools, including various materials containing environmentally friendly components of natural origin and having high efficiency at low cost.

Water is widely known as a fire extinguishing agent. However, water can only be used to extinguish, and not to prevent fires. In this case, the insufficiently high efficiency of this tool leads to its high consumption. For example, when extinguishing forest fires, about 12-15 kg / m of water is required, which may not always be feasible in the circumstances.

Various solutions of retardants (flame retardants) in water are also widely known. However, as a rule, retardants are complex chemical compounds (for example, based on diammonium phosphate), which pollute the environment, and also require the use of sophisticated production technology, sophisticated equipment for mixing and feeding to the fire site (tanks and discharge devices of complex design, control of the cooking process using a computer). All this leads to a significant increase in the cost of the fire fighting process and significantly reduces the possibility of their use for preventive purposes. Fire water suspensions are also known that contain components of natural origin, for example, sand, clay and water (Zυ, A, 494164, Ab 201/10, 1973; 54, A, 626780, Α62 01/10, 1976). Moreover, the known aqueous suspension (5υ, A, 626780) contains these components in their next ratio, May. % sand - 5-20 clay - 1-5 water - the rest.

These compositions are environmentally friendly and cheap product. However, they have rather low adhesive and insulating properties, which do not allow moisture to be retained on the treated surface until the water evaporates completely and reliably isolate the pyrolysis products. This is due to the fact that sand is a loose rock, consisting mainly of grains of various minerals and rock fragments ranging in size from 100 to 5000 microns, and has a slight admixture of silt and clay particles (the last no more than 3%) ranging in size from 10 to 100 microns . The presence in the solution of these large fractions, insoluble in water, leads to the formation of a precipitate in the suspension, and is also a formative material for fire fighting equipment (pipelines, pouring devices and the like). In addition, although the presence of clay improves the adhesive properties of the composition, the presence of sand practically neutralizes these properties, since the sand has a high flowability and does not allow the suspension components (in particular, water) to be retained on the treated surfaces. All of the above limits the use of these suspensions and allows them to be used mainly in extinguishing and localizing steppe fires.

Disclosure of Invention

The basis of the present invention is the task to create a fire-fighting mineral-water suspension with such components that would ensure an increase in its adhesive and insulating properties, which would make it possible to use it both to extinguish and to prevent fires.

This problem was solved by creating a fire-resistant mineral-water suspension containing clay and water, which according to the invention additionally contains liquid glass in a mass ratio to clay from (1: 1) to (1:10), respectively.

The presence of liquid glass significantly increases the adhesive and insulating properties of the proposed suspension. This is due to the fact that liquid glass has high adhesion properties, is highly soluble in water, does not lead to the formation of sediment and allows you to keep clay particles in suspension. In this case, liquid glass in combination with clay holds water on the treated surface until it completely evaporates, regardless of the angle of inclination of this surface to the horizon. In addition, after water evaporation, a coating of silicon oxides is formed on the treated surface, which prevents oxygen from accessing the fire source, and also prevents the energy supply from the fire source, which limits its spread, and to this source, which eliminates the possibility of re-ignition .

The indicated properties of the proposed suspension allow its use in fires of various types and capacities, and the name is BUT:

- city fires: when extinguishing fires in residential and industrial buildings, as well as other administrative, scientific, educational and similar objects;

- forest and steppe fires: the direct extinguishing of these fires, as well as the protection of nearby territories from this type of fire;

- fires at oil fields, as well as fires of spilled oil products as a result of accidents and natural disasters.

Moreover, the efficiency of use of the proposed suspension is several orders of magnitude higher than the efficiency of use, for example, of water. That is, the extinguishing water consumption, for example measures, forest fire is, on average, 12-15 kilograms per square meter of burning surface, and the consumption of the proposed suspension is 0.12-0.15 kilograms per square meter when the same result is achieved, which significantly reduces the cost of extinguishing fires, especially powerful and large-scale.

In addition, these qualities of the proposed suspension can significantly expand the scope of its application. That is, use it not only to extinguish, but also to prevent fires, for example, to cover surfaces of combustible materials inside buildings and structures, as well as to cool and isolate surfaces adjacent to the fire source with it.

To extinguish various types of fires, it is advisable to use a suspension containing liquid glass with its mass ratio to clay from (1: 1) to (1: 6), respectively, and the total content of liquid glass and clay in the suspension from 20 to 60 wt. %, water the rest.

To prevent fires, it is advisable to use a slurry containing liquid glass with its mass ratio to clay from (1: 4) to (1:10), respectively, and the total content of liquid glass and clay in the suspension from May 60 to 80. %, water the rest.

In this case, it is possible that the suspension contains components in their next ratio, May. %: water glass - 7-16 clay - 13-72 water - the rest.

The proposed fire-fighting mineral-water suspension has high adhesive and insulating properties, which allows it to be used to extinguish fires of various types and capacities, and to prevent fires for preventive purposes.

The best embodiment of the invention

The proposed fire-fighting mineral water suspension Sia contains water glass, clay and water. In this case, the suspension contains liquid glass in an amount ensuring its mass ratio with clay from (1: 1) to (1:10), respectively. That is, one mass part of liquid glass in suspension accounts for from 1 to 10 mass parts of clay. Moreover, to extinguish fires, it is better to use a suspension in which 1 to 6 mass parts of clay (mass ratio from (1: 1) to (1: 6), respectively) falls on one part of liquid glass, and it is better to use a suspension to prevent fires, in which one part of liquid glass accounts for from 4 to 10 mass parts of clay (mass ratio from (1: 4) to (1:10), respectively).

The total content of water glass and clay in the suspension can vary from May 20 to May 80. %, the rest is water. In this case, the content of components in suspension is possible at their next ratio, May. %: water glass 7-16 clay 13-72 water the rest. As liquid glass, for example, an aqueous solution of sodium silicate or potassium silicate can be used.

At the indicated ratios of water glass, clay and water, each clay particle is enveloped in a solution of water glass and is kept in suspension in suspension. This ensures uniformity of the suspension, facilitates its crushing into droplets during spraying, since liquid glass reduces the surface tension of the suspension.

If in a suspension the mass amount of liquid glass relative to the mass amount of clay is less than 1: 1, then liquid glass will not be enough to keep all clay particles in suspension, which will lead to a decrease in the insulating properties of the suspension.

If in the suspension the mass amount of clay relative to the mass amount of liquid glass is more than 10: 1, it will be difficult to apply the suspension to the surface to be treated, and it will also be difficult to keep the suspension on this surface. surface, because due to the large amount of clay, the flowability of the suspension will increase significantly during the evaporation of water.

If in suspension, reduce the content of water glass less than May 7. %, the effect of maintaining clay particles in suspension may decrease. In addition, the specified decrease in the content of liquid glass can lead to a decrease in the insulating properties of the suspension, since it may not be enough to form a coating of silicon oxides on the treated surface after evaporation of moisture. If the content of liquid glass is increased to more than 16 wt.%, Then the density of the suspension will increase, which can lead to difficulties in feeding it to the fire.

If the clay content in the suspension is reduced to less than 13 wt.%, The adhesive properties of the suspension will decrease, as a result of which it will be difficult to retain moisture on the treated surface until it completely evaporates.

If the clay content is increased to more than 72 wt.%, Then there will be a problem of transferring it to a finely dispersed state and obtaining a homogeneous suspension, which can lead to difficulties in feeding it to the fire. In addition, this will increase the viscosity of the suspension.

The proposed suspension is prepared as follows. First, liquid glass is dissolved in water, and then clay is added to the resulting solution and stirred, for example, in a concrete mixer until homogeneous. To reduce the cooking time, it is advisable to grind the clay beforehand.

The resulting suspension is a microheterogeneous free-dispersion system in which the dispersion medium is water and the dispersed phase is water glass and clay. Moreover, the ratio of the latter can vary within the indicated wide limits, which does not significantly affect the fire extinguishing and fire retardant properties of the suspension. Moreover, the suspension has high adhesive and insulating properties.

The quantitative composition of the components in suspension, as indicated was called above, is determined by its purpose, that is, whether it is used as a fire suppressant or fire retardant.

So, for example, when extinguishing fires in residential buildings, it is advisable to use a solution with a low total content of clay and liquid glass (about 20 wt.%, The rest is water), since the main task is to cool the focus. At the same time, it is advisable to cover the walls of buildings adjacent to the fire source with a composition with a high total content of these components (about 60-80 wt.%, Water - the rest). A similar approach should be in extinguishing fires at enterprises, warehouses, storage facilities and the like.

When extinguishing forest and steppe fires, it is most optimal to use 40-60 wt.% The total content of clay and liquid glass, since this composition, as shown by experiments on model and artificially induced real forest fires, has good cooling (water is kept in a finely dispersed state on a hot surface) and insulating (a sufficiently large amount of clay and water glass) properties. The amount of water in the specified range depends on the purpose of the suspension, and a decrease in its content below the lower limit or an increase in its content above the upper limit leads to the need to increase or decrease the content of the dispersed phase in the suspension, which can lead to the negative consequences described above.

The resulting suspension is used by spraying with various existing methods (for example, using pumps, spilling from aircraft or helicopters). The most effective are dispersion methods using the energy of an explosion or pressure accumulators (for example, air, powder), since they allow dispersing a suspension to droplets with a diameter of less than 10 microns, significantly increasing the surface of interaction with the flame.

For a better understanding of the invention, specific examples of its implementation are given below. Example The method described above was used to prepare the proposed suspension with different content of components in it. Then, its fire-retardant properties were determined on wooden samples, for which standard matches with a removed head were taken. 5 Wooden samples were coated with the proposed suspension with a different content of components, placed in a gas burner flame (the temperature in the burner flame was 1150 + -20 ° C), and the time to ignition of the sample or before its smoldering was determined, since in most cases on the sample

10, after evaporation of water, a coating was formed from a solid solution of water glass and clay. In this case, the temperature inside the coating was insufficient to ignite the sample, and only caused its slow smoldering, which was determined by the appearance of smoke from under the coating at the ends of the sample.

15 For comparison, the ignition time of a sample previously treated with water was similarly determined.

A different ratio of components in a suspension with a volume of approximately 0.04 m, as well as the time until they ignite (start to smolder) are given in the examples summarized in the following table.

20 person, in which for comparison in example Ν 31 shows the time until the ignition of the sample treated with water.

Table

ΝΝ! Total! Content ratio of components! Time to call! content! liquid wt.%! Goran (nacha-! Liquid! glass and ι _la corruption) • glass! clay, May. liquid clay water! sample,! clay! glass parts! seconds! wt.%! (near)

1 20 1.9 7 13 80 7.8 2 26 1.6 10 16 74 7.7

3 21 3.2 6 19 75 10.1

As can be seen from the above examples, the time to ignition of a sample treated with the proposed suspension, with any content of these components in it from about one and a half to more six times the time required to ignite a sample treated with water.

In addition, the formation on the surface of the samples of a solid coating of liquid glass and clay, which prevents the ignition of the samples, clearly indicates the high adhesive and insulating properties of the proposed suspension.

Industrial applicability

The present invention can be used as a fire suppressant or fire retardant in fires of various types and capacities, namely: city fires, forest and steppe fires, fires in the oil fields. In addition, the proposed suspension can be used to prevent fires, as well as to protect against ignition of objects adjacent to the fire source by applying it to the surface of products made of combustible materials inside various structures or on the surface located next to the fire source.

Claims

CLAIM

1. Fire-fighting mineral-water suspension containing clay and water, such as the fact that it additionally contains liquid glass with its mass ratio to clay from (1: 1) to (1 : 10), respectively.

2. Fire-fighting mineral-water suspension according to π.1, with the fact that it contains liquid glass with its mass ratio to clay from (1: 1) to (1: 6), accordingly.

3. Fire-fighting mineral-water suspension according to π.1, with the fact that it contains water glass with its mass ratio to clay from (1: 4) to (1:10), respectively.

4. Fire-prevention mineral-water suspension according to π.1, with the fact that it contains components in their next ratio, May. %: the total content of liquid glass and clay 20-80 water the rest.

5. Fire-fighting mineral-water suspension according to π.1, with the fact that it contains components in their next ratio, May. %: water glass 7-16 clay 13-72 water the rest.