RU2642860C1 - Environmentally safe foam-forming composition of heat-resistant foam based on "soap nut" - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: foam-forming composition of heat-resistant foam is described, for preventing and extinguishing fires, comprising a surfactant, a basic aluminium chloride, sodium bicarbonate, and water, wherein the composition contains a surfactant - a soap nut in the following ratio of components, wt %: basic aluminium chloride, Al₂(OH)₅Cl - 0.50, sodium bicarbonate, NaHCO₃ - 0.24, surfactant - soap nut - 0.40, water - the rest.

EFFECT: formulation is obtained that does not include synthetic surfactants and has an almost absolute environmental safety.

1 tbl, 2 ex

Description

The invention relates to means of preventing and extinguishing fires, and can also be used for the degassing of toxic materials, dust suppression, in medicine, in pharmaceuticals and in agriculture.

It is known that water and micelle-forming surface-active substances (surfactants) are the main components of fire extinguishing foaming compositions. To increase the effectiveness of fire fighting in the foaming compositions include various additives that improve the quality of the foam.

Known foaming composition - Pat. US No. 3554912, CL A62D 1/00, 1971 - to obtain heat-resistant foam of low multiplicity, suitable for extinguishing fires. The composition includes: from 2 to 40% stabilizer - highly basic aluminum salt Al ₂ (OH) ₅ Cl; from 0.02 to 4% of a surfactant (SAS) containing from 6 to 18 carbon atoms per acid group; and water - the rest is up to 100%.

The disadvantage of this and all other modern blowing agents used in fire fighting is the use of synthetic synthetic surfactants in the compositions, which have recently been the most dangerous environmental pollutants.

The named drawback is devoid of the composition of US Pat. RU No. 2465028 C2 - ENVIRONMENTALLY SAFE FOAM FORMING COMPOSITION OF HEAT RESISTANT FOAM. Published: October 27, 2012, bul. No. 30.

In this blowing agent, synthetic mineral (petroleum) surfactants are replaced by natural ones contained in beer.

The composition includes, by weight. %:

Basic aluminum chloride, Al ₂ (OH) ₅ Cl 1,0 Sodium bicarbonate, NaHCO ₃ 0.5 Beer thirty Water Rest

The disadvantage of this composition is the use of beer - a food product of long and laborious manufacture.

The closest in composition and used natural surfactant, adopted by us as a prototype, is Pat RU No. 2452544 C1 - FOAM-FORMING COMPOSITION OF HEAT RESISTANT FOAM BASED ON HOP. Published: 06/10/2012. Bull. No. 16.

The composition includes, wt.%:

Basic aluminum chloride, Al ₂ (OH) ₅ Cl 1,0 Sodium bicarbonate, NaHCO ₃ 0.5 Surfactant - hops 0.4 Water Rest

The disadvantage of the foaming composition is the use of hops, laborious in the agricultural cultivation and production of natural surfactants, which increases the cost of the final product.

The foaming composition using surfactants (saponins) "soap nuts" ^{*) is} devoid of this drawback in the following ratio of components in wt. %:

Basic aluminum chloride, Al ₂ (OH) ₅ Cl 0.50 Sodium bicarbonate, NaHCO ₃ 0.24 Surfactant - soap nut 0.40 Water Rest

To obtain the composition according to the invention, the following substances are used:

1. The main aluminum chloride is Al ₂ (OH) ₅ Cl, TU 216-350-002-39928758-02.

2. Sodium bicarbonate (baking soda), GOST 2156-76.

3. Fruits of the S. Trifoliatus soap tree - dried sapindus fruits, TU 9158-003-8737-0228-2012.

4. Drinking and hard water - according to NPB 304-2001.

All testing of the compositions is carried out according to standard methods recommended when developing new foaming compositions GOST R 50588-12. Foaming agents for extinguishing fires. /General technical requirements and test methods/.

Two concentrates are prepared for testing.

1. Obtaining a concentrate of foaming agent from the "soap nut". The hard shells of the fruit of the “soap nut” 12 g, pour 150 ml of water and boil over low heat for 30 minutes, periodically kneading the fruit. Then, at room temperature, the solution is filtered from insoluble precipitate. The volume of the extract should be no more than 37.5 ml, which is achieved by boiling, or by diluting the extract with water. To the extract was added 12.5 ml of OHA - Al ₂ (OH) ₅ Cl TU 216-350-002-39928758-02.

A total of 50 ml of a dark brown concentrated foaming agent is obtained with the following characteristics: density = 1.08; TDS = 1730; ORP = 173;

The freezing point of the concentrate is + 5 ° C. After freezing and thawing, the properties of the foaming agent do not change.

2. Obtaining a concentrated solution of soda.

9.6 g of drinking soda is dissolved in 100 ml of water at room temperature. During storage of a concentrated soda solution, slight crystalline precipitation is allowed.

Both concentrates 1 and 2 can be stored for a long time in a closed plastic container without a noticeable change in properties.

The compositions of both concentrates are balanced so that in the working solution the components react according to the reaction:

Al ₂ (OH) ₅ Cl + NaHCO ₃ = = = Al ₂ (OH) ₆ + NaCl + CO ₂

in this case, surfactants are not involved in chemical interaction.

Foaming agent concentrate (1) is designed for the use of fire fighting equipment with a standard dosage of 6% -volume, in working solution.

Examples of the preparation of combined foaming compositions of heat-resistant foam.

Example 1

6 ml of a concentrated blowing agent solution is placed in a measuring cup and adjusted to 97 ml with water. Then with stirring, add 3 ml of a solution of concentrated soda. A milky colloidal solution is formed.

Structure:

Basic aluminum chloride, Al ₂ (OH) ₅ Cl 0.50 Sodium bicarbonate, NaHCO ₃ 0.24 Surfactant - soap nut 0.40 Water Rest

100 ml of the solution is placed in a RT-1 device and the mixer is turned on for 30 seconds at a speed of 4000 rpm to obtain a foam. The multiplicity of the foam 4.8. The time of spontaneous destruction of the foam is noted — the formation of a compartment of 25 ml — 60 minutes; 50 ml - 180 minutes, then the compartment does not add up to 240 minutes.

Example 2

Drinking water up to 94 ml is added to 3 ml of concentrated soda solution (0.24 g). Then, while stirring the solution, 6.0 ml of concentrated blowing agent (1) with a content of 0.5 g of basic aluminum chloride — Al ₂ (OH) ₅ Cl. A relatively clear yellowish solution forms with (pH) = 8.5.

100 ml of the solution is placed in a RT-1 device and the mixer is turned on for 30 seconds at a speed of 4000 rpm to obtain a foam. The multiplicity of the foam is 4.5. The time of spontaneous destruction of the foam is noted — compartment formation: 25 ml — 10 min; then the compartment does not add up to 60 minutes; 50 ml - 120 min. Further, the compartment slowly accumulates.

The comparative data of examples 1 and 2 show that the order of addition of concentrates to the working solution of the foaming agent is significant, with preference being given to example 1, where a concentrated soda solution is added to a solution of diluted foaming agent with a coagulant.

When used for the preparation of binary compositions in fresh water of varying degrees of hardness, no noticeable changes in the properties of the foam are observed.

The table shows comparative data for the optimal composition of the foaming agent of the prototype and the proposed.

Comparative data show that the proposed composition includes 2 times less aluminum oxychloride - Al ₂ (OH) ₅ Cl and, accordingly, 2 times less drinking soda with an equal content of surfactants, which helps to reduce the cost of the fire extinguishing composition and meets the requirements of the task.

An important advantage of using soap nuts is the possibility of agro-industrial use of perennial trees that do not require special care to obtain surfactants and their environmental component in the plant world of the earth.

^* ) Extract from Wikipedia.

The genus includes about 15 species.

Soap nuts are called fruits of the sapindus tree - S. trifoliatus growing in the tropics and subtropics. The fruits of this tree are berries, the peel of which hardens over time, therefore the people got the name “soap nut”.

Trees reach a height of 25 meters. The leaves are spear-shaped, 7-10 cm long. Soap trees bloom in small greenish-white flowers; the fruits ripen in November-December. Trees bear fruit from 3 years and live without human intervention for about 100 years.

Soap nuts S. Trifoliatus in appearance look like small dry rose hips.

Fruits have a fruity-floral smell from weak to strong. Color from light brown to black and red. The fruit size is about 1.5 cm. The content of saponins-glycosides is up to 38% (average 20%). They contain more tannins and dyes, and have a more stable foam than S. Mukorossi.

Saponins are natural blowing agents (from lat. Sapo - “soap”); they act as surface-active substances (surfactants), but unlike synthetic surfactants, they completely decompose in the environment without harming it.

Claims (2)

Foaming composition of heat-resistant foam for the prevention and suppression of fires, including a surface-active substance (surfactant), basic aluminum chloride, sodium bicarbonate and water, characterized in that the composition uses surfactant - soap nut in the following ratio, wt.%: Basic aluminum chloride, Al ₂ (OH) ₅ Cl 0.50 Sodium bicarbonate, NaHCO ₃ 0.24 Surfactant - soap nut 0.40 Water Rest