3.2.1. Determining the tactical capabilities of units without installing vehicles on water sources. Without installation on water sources, fire trucks are used, which take out a supply of water, foam concentrate and other fire extinguishing agents to fires. These include fire trucks, airfield service fire trucks, fire trains, etc.

The fire extinguishing leader must not only know the capabilities of the units, but also be able to determine the main tactical indicators:

operating time of barrels and foam generators;

· possible area of ​​extinguishing with air-mechanical foam;

· the possible volume of extinguishing with medium expansion foam with the foam concentrate or solution available on the machine.

Working hours of water shafts from fire engines without installing them on water sources is determined by the formula:

t \u003d (V c - N p V p) / N st Q st 60, (3.1)

where t is the operating time of the shafts, min; V c - the volume of water in the tank of a fire engine, l; N p - the number of sleeves in the main and working lines, pieces; V p - the volume of water in one sleeve, l (see clause 4.2); N st - the number of water trunks operating from a given fire engine, pcs; Q st - water consumption from trunks, l / s (see tables 3.25 - 3.27).

The operating time of foam barrels and medium expansion foam generators is determined by:

t \u003d (V p-ra - N p V p) / N SVP (GPS) Q SVP (GPS) 60, (3.2)

where V p-ra is the volume of a 4 or 6% solution of a foaming agent in water, obtained from the filling tanks of a fire engine, l; N SVP (GPS) - the number of air-foam barrels (SVP) or medium expansion foam generators (GPS), pcs .; Q SVP (GPS) - the flow rate of an aqueous solution of a foaming agent from one barrel (SVP) or generator (GPS), l / s (see Table 3.32).

The volume of the solution depends on the amount of foaming agent and water in the filling tanks of the fire truck. To obtain a 4% solution, 4 liters of foam concentrate and 96 liters of water are needed (24 liters of water per 1 liter of foam concentrate), and 6 liters of foam concentrate and 94 liters of water (for 1 liter of foam concentrate 15.7 liters of water) for a 6% -1 solution. Comparing these data, we can conclude that in some fire engines without installation on water sources, the entire foaming agent is consumed, and part of the water remains in the filling tank, in others, the water is completely consumed, and part of the foaming agent remains.

To determine the volume of an aqueous solution of a foaming agent, you need to know how much water and foaming agent will be consumed. For this purpose, the amount of water. per 1 liter of foaming agent in the solution, we denote K in (for a 4% solution, 24 liters are wounded, for a 6% solution - 15.7). Then the actual amount of water,

per 1 liter of foaming agent is determined by the formula:

K f \u003d V c / V according to (3.3)

where V c - the volume of water in the tank of a fire truck, l; V on - the volume of the foaming agent in the tank of the fire engine, l.

The actual amount of water K f per 1 liter of foam concentrate is compared with the required K v. If K f >K in, then the foaming agent located on one machine is completely consumed, and part of the water remains. If K f<К в, тогда вода в емкости машины расходуется полностью, а часть пенообразователя остается.

Amount of aqueous solution foaming agent at the full flow of water located on the fire truck is determined by the formula:

V p-ra \u003d V c / K in + V c (3.4)

where V p-ra is the amount of an aqueous solution of a foaming agent, l.

When the foaming agent of this fire engine is completely used up, the amount of solution is determined by the formula:

V r-ra \u003d V by K in + V by (3.5)

where V is the amount of foam concentrate on the machine, l.

Possible extinguishing area flammable and combustible liquids are determined by the formula:

S t \u003d V r-ra / I s t t p 60 (3.6)

where S t is the possible extinguishing area, m 2; I s t - normative intensity of the solution supply for extinguishing a fire, l / (m 2 s) (see table. 2.11); t p - estimated extinguishing time, min (see clause 2.4).

Volume of air-mechanical foam low and medium multiplicity is determined by the formulas:

V p \u003d V p-ra K; V p \u003d V p K p (3.7)

Where V p is the volume of foam, l; K - foam ratio; V p - the amount of foaming agent on the machine or its consumable part, l; K p is the amount of foam obtained from 1 liter of foam concentrate, l (for a 4% solution it is 250 l, for a 6% solution it is 170 l with a multiplicity of 10 and, respectively, 2500 and 1700 with a multiplicity of 100).

Extinguishing volume(localization) air-mechanical medium expansion foam is determined by the formula

V t \u003d V p / K s (3.8)

where V t is the volume of fire extinguishing; V p - foam volume, m 3; K s - foam reserve factor, taking into account its destruction and loss. It shows how many times more it is necessary to take foam of medium expansion in relation to the volume of quenching; K s \u003d 2.5 - 3.5.

Examples. To substantiate the tactical possibilities of the detachment of the armed AC-40(131)137 without installing it on a water source.

1. We determine the operating time of two water trunks with a nozzle diameter of 13 mm at a head of 40 m, if one sleeve with a diameter of 77 mm is laid before the branching, and the working lines consist of two sleeves with a diameter of 51 mm to each trunk:

t \u003d (V c - N r V r) / N st Q st 60 \u003d 2400 - (1´90 + 4´40) / (2´3.7´60) = 4.8 min.

2. We determine the operating time of valuable trunks and generators. For this purpose, it is necessary to use the volume of an aqueous solution of a foaming agent, which can be obtained from AC-40 (131) 137

K f \u003d V c / V by \u003d 2400/150 \u003d 16 l.

Therefore, K f \u003d 16\u003e K in \u003d 15.7 with a 6% solution. Therefore, the volume of the solution is determined by the formula:

V solution \u003d V by K in + V by \u003d 150 ´ 15.7 + 150 \u003d 2500 l

We determine the operating time of one SVP-4 foam barrel if the pressure at the barrel is 40 m, and the working line consists of two hoses with a diameter of 77 mm:

t \u003d (V p-ra - N p V p) / N SVP Q SVP 60 \u003d (2500 - 2´90) / 1´8´60 \u003d 4.8 min.

We determine the operating time of one GPS-600 if the pressure at the generator is 60 m, and the working line consists of two hoses with a diameter of 66 mm:

t \u003d (V p-ra - N p V p) / N GPS Q GPS 60t \u003d (2500 - 2´7) / 1´6´60 \u003d 6.5 min.

3. We determine the possible area for extinguishing flammable and combustible liquids under the following conditions:

when extinguishing gasoline with medium expansion air-mechanical foam I s \u003d 0.08 l / (m 2 s) and t p \u003d 10 min (see clauses 2.3 and 2.4):

S t \u003d V r-ra / I s t p 60 \u003d 2500 / 0.08´10´60 \u003d 52 m 2;

when extinguishing kerosene with air-mechanical foam of medium expansion (I s \u003d 0.05 l / (m 2 s) and t p \u003d 10 min, see table. 2.10 and clause 2.4)

S t \u003d V r-ra / I s t p 60 \u003d 2500 / 0.05´10´60 \u003d 83 m 2;

when extinguishing oil with low expansion air-mechanical foam (I s \u003d 0.10 l / (m 2 s) and t p \u003d 10 min, see table. 2.10 and clause 2.4)

S t \u003d V r-ra / I s t p 60 \u003d 2500 / 0.1´10´60 \u003d 41 m 2.

4. We determine the possible volume of extinguishing (localization) of the fire with medium expansion foam (K = 100). For this purpose, using formula (3.7), we determine the volume of foam:

V p \u003d V r-ra K \u003d 2500´100 \u003d= 250000 l or 250 m 3.

From the extinguishing conditions (room layout, ion supply, normative extinguishing time, density of combustible load, possibility of collapse, etc.) we take the value Kz ""9^ Then the extinguishing volume (localization) will be equal to:

V p \u003d V p / K s \u003d 250/3 \u003d 83 m 3.

It follows from the above example that a squad armed with AC-40 (131) 137 without installing the machine on a water source can ensure the operation of one barrel B for 10 minutes, two barrels B or one A for 5 minutes, one foam barrel SPV-4 within 4 - 5 minutes, one GPS-600 generator within 6 - 7 minutes, eliminate the combustion of gasoline with medium expansion foam on an area up to 60 m 2, kerosene - up to 80 m 2 and oil with low expansion foam - up to 40 m 2, extinguish (localize) a fire with medium expansion foam in a volume of 80 - 100 m 3.

In addition to the specified fire extinguishing work, the uninvolved part of the personnel of the department can perform individual work on rescuing people, opening structures, evacuating material assets, installing stairs, etc.

3.2.2. Determination of the tactical capabilities of units with the installation of their vehicles on water sources. Units armed with fire trucks carry out combat operations on fires with the installation of vehicles on water sources in cases where the water source is located next to a burning object (up to about 40 - 50 m), and also when the stock of fire extinguishing agents taken out by vehicle is not enough to eliminate fire and containment of the spread of fire in a decisive direction. In addition, divisions on tank trucks work from water sources after the stock of fire extinguishing agents is used up, as well as by order of the fire extinguishing manager when they arrive at the fire on an additional call. Fire pumps, pump-hose cars, fire pumping stations, motor pumps and other fire engines that do not deliver a supply of water to a fire are installed on water sources in all cases.

When fire trucks are installed on water sources, the tactical capabilities of subunits increase significantly. The main indicators of the tactical capabilities of units with the installation of vehicles on water sources are: the maximum distance for the supply of fire extinguishing agents, the duration of the operation of fire nozzles and generators at water sources with a limited supply of water, the possible area for extinguishing flammable liquids and the volume in the building when it is filled with medium-expansion air-mechanical foam .

The maximum distance for the supply of fire extinguishing agents on fires is considered to be the maximum length of the hose lines from fire engines installed on water sources to branches located at the fire site, or to the positions of trunks (generators) supplied for extinguishing. The number of water and foam barrels (generators) supplied by the squad for extinguishing fires depends on the maximum distance, the number of combat crew, and also on the current situation.

To work with trunks in different situations, an unequal number of personnel is required. So, when one trunk B is fed at ground level, one person is needed, and when it is raised to a height, at least two. Two people are needed when feeding one barrel A at ground level, and at least three people are needed when feeding it to a height or when working with a rolled nozzle. To supply one barrel A or B to rooms with a smoky or poisoned environment, a link of gas and smoke protectors and a security post are required, that is, at least four people, etc. Therefore, the number of extinguishing devices that the department can provide is determined by the specific situation on fire.

Limit distance for the most common combat deployment schemes (see Fig. 3.2) is determined by the formula:

l pr = ´20, (3.9)

where l pr - limiting distance, m; H n - pressure on the pump, m; H pr - pressure at the branching, fire monitors and foam generators. m (pressure loss in working lines from a branch within two or three sleeves in all cases does not exceed 10 m, so the head at the branch should be taken 10 m more than the head at the nozzle of the trunk attached to this branch); ± Z m - the highest height of ascent (+) or descent (-) of the terrain at the maximum distance, m; ± Z pr - the highest lifting or lowering height of extinguishing devices (barrels, foam generators) from the installation site of the branch or the surrounding area on the fire, m; S is the resistance of one fire hose (see Table 4.5); Q 2 - total water consumption of one of the busiest main hose lines, l/s; SQ 2 - pressure loss in one sleeve of the main line, m (given in Table 4.8).

The maximum distance obtained by calculation for the supply of fire extinguishing agents should be compared with the supply of hoses for the main lines located on the fire engine, and, taking this into account, the calculated indicator should be adjusted. If there are not enough hoses for the trunk lines on the fire engine, it is necessary to organize interaction between the units that arrived at the fire site, ensure the laying of lines from several units and take measures to call hose cars.

The duration of the devices extinguishing depends on the supply of water in the water source and the foaming agent in the filling tank of the fire engine. Water sources that are used to extinguish fires are conditionally divided into two groups: water sources with an unlimited supply of water (rivers, large reservoirs, lakes, water supply networks) and water sources with a limited supply of water (fire reservoirs, spray pools, cooling towers, water towers, etc.). ).

The duration of operation of extinguishing devices from water sources with a limited supply of water is determined by the formula:

t \u003d 0.9 V in / N pr Q pr 60, (3.10)

where V in - water supply in the reservoir, l; N pr - the number of devices (barrels, generators) supplied from all fire engines installed on the bottom water source; Q pr - water consumption by one device, l / s.

Duration of operation of foam barrels and generators depends not only on the supply of water in the water source, but also on the supply of foam concentrate in the filling tanks of fire trucks or delivered to the fire site. The duration of the operation of foam shafts and generators in terms of the stock of the foam concentrate is determined by the formula;

t = V over /N SVP(GPS) Q SVP(GPS) 60, (3.11)

where Vpo is the stock of foaming agent in the filling tanks of fire trucks. l; N SVP (GPS) - the number of foam barrels or generators supplied from one fire engine, pcs.; Q SVP(GPS) - foam concentrate consumption by one foam shaft or generator, l/s.

According to formula (3.11), the operating time of foam barrels and generators from fire tank trucks is determined without installing them on water sources, when the amount of water on the machine is sufficient for the full consumption of the foam concentrate in the tank.

Possible areas for extinguishing flammable and combustible liquids when installing fire engines on water sources, they are determined by the formula (3.6). At the same time, it must be remembered that the volume of the solution is determined taking into account the consumption of the entire foam concentrate from the foam tank of the fire engine according to the formula (3.5) or

V r-ra \u003d V by K r-ra, (3-12)

where K solution is the amount of solution obtained from 1 l of foaming agent (K solution = K + 1 at 4% solution K solution = 25 l, at 6% solution K solution = 16.7 l)

Possible volume of fire extinguishing (localization) determined by formula (3.8). In this case, the amount of solution is found by formulas (3.5) or (3.12), and the volume of foam - by (3.7).

To accelerate the calculation of the volume of air-mechanical foam of low and medium expansion obtained from fire engines with their installation on a water source at the expense of the entire supply of foam concentrate, the following formulas are used.

When extinguishing a fire with air-mechanical foam of low expansion (K = 10), 4- and 6% aqueous solution of a foaming agent:

V p \u003d V by /4 and V p \u003d V by /6, (3.13)

where V p is the volume of foam, m 3; V on - the volume of the foaming agent of the fire engine, l; 4 and 6 - the amount of foaming agent, l, consumed to obtain 1 m 3 of foam, respectively, with a 4- and 6% solution.

When extinguishing a fire with air-mechanical foam of medium expansion (K = 100), 4- and 6% aqueous solution of a foaming agent

V p \u003d (V by /4)´10 and V p \u003d (V by /6)´10, (3.14)

Examples. Substantiate the main tactical capabilities of a squad armed with a pump-hose vehicle ANR-40(130) 127A.

1. Determine the maximum distance for the supply of one trunk A with a nozzle diameter of 19 mm and two trunks B with a nozzle diameter of 13 mm, if the pressure at the trunks is 40 m, and their maximum lift is 12 m, the elevation of the terrain is 8 m, rubberized sleeves with a diameter of 77 mm:

l pr \u003d ´20 \u003d ´20 \u003d 180 m.

The obtained limiting distance is comparable with the number of branches on ANR-40(130) 127A (33 arms ´ 20 m = 660 m).

Consequently, the squad, armed with ANR (130) 127A, ensures the operation of the trunks according to the specified scheme, since the number of sleeves available on the machine exceeds the maximum distance according to the calculation.

2. Determine the duration of operation of two shafts A with a nozzle diameter of 19 mm and four shafts B with a nozzle diameter of 13 mm at a pressure at the shafts of 40 m, if AHP-40(130)127A is installed on a reservoir with a water reserve of 50 m3:

t \u003d 0.9 V in / N pr Q pr 60 \u003d 0.9 ´ 50´1000 / (2´7.4 + 4´3.7) ´60 \u003d 25 min.

3. Determine the duration of operation of two GPS-600 from ANR-40 (130) 127A, installed on the river, if the head of the generators is 60 m.

According to the table 3.30 we find that one GPS-600 at a head of 60m consumes a foam concentrate of 0.36 l / s

t = V by /N HPS Q HPS 60 = 350/2´0.36´60 = 8.1 min.

4. Determine the possible area for extinguishing combustible liquids with low expansion air-mechanical foam. For this purpose, it is necessary to find a 6% volume of the solution using the formula (3.5)

V solution \u003d V by K in + V by \u003d 350´15.7 + 350 \u003d 5845 l;

S t \u003d V r-ra / I s t p 60 \u003d 5845 / (0.15´10´60) \u003d 66 m 2.

5. Determine the possible area for extinguishing kerosene with medium expansion foam

S t \u003d V r-ra / I s t p 60 \u003d 5845 / (0.15´10´60) \u003d 195 m 2.

V. Determine the possible area for extinguishing gasoline with medium-expansion air-mechanical foam

S t \u003d V r-ra / I s t p 60 \u003d 5845 / (0.08´10´60) \u003d 120 m 2.

7. Determine the possible volume of extinguishing (localization) with medium-expansion air-mechanical foam if a 4% foam concentrate solution was used with a filling factor K 3 = 2.5. Determine the volume of the solution and the volume of the foam

V solution \u003d V by K in + V by \u003d 350´24 + 350 \u003d 8750 l;

V p \u003d V solution K \u003d 8750´100 \u003d 875000 l or 875 m 3;

V t \u003d V p / K \u003d 875 / 2.5 \u003d 350 m 3.

Consequently, a squad armed with ANR-40 (130) 127A, when installing the machine on a water source, can ensure the operation of hand and fire monitors, one or two GPS-600 or SVP-4 for 16 - 8 minutes, extinguish a flammable liquid with air-mechanical foam low expansion on an area up to 65 m 2, and with medium expansion foam on an area up to 200 m 2, eliminate the combustion of a flammable liquid with medium expansion foam up to 120 m 2 and eliminate (localize) a fire with medium expansion foam at a 4% foam concentrate solution in a volume of up to 350 m3.

Thus, knowing the methodology for substantiating the tactical capabilities of fire departments with the installation of fire trucks on water sources, it is possible to determine in advance the possible volume of hostilities in a fire and organize their successful implementation.

FOAMERS
FOR FIRE EXTINGUISHING

ABOUT general technical requirements
and test methods

Moscow Standartinform 2012

Foreword

The goals and principles of standardization in the Russian Federation are established by the Federal Law of December 27, 2002 No. 184-FZ "On Technical Regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic Provisions»

About the standard

1 DEVELOPED by the State Educational Budgetary Institution of Higher Professional Education "Academy of the State Fire Service" of the Ministry of Emergency Situations of Russia (Academy of the State Fire Service of the Ministry of Emergency Situations of Russia) and the Federal State Budgetary Institution "All-Russian Order of the Badge of Honor" Research Institute of Fire Defense of the Ministry of Emergency Situations of Russia" (FGBU VNIIPO EMERCOM of Russia)

2 INTRODUCED by the Technical Committee for Standardization TK 274 "Fire Safety"

3 APPROVED AND PUT INTO EFFECT by the Order of the Federal Agency for Technical Regulation and Metrology of May 14, 2012 No. 66-st

5 REVISION. January 2013

Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments - V monthly published information signs "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also posted in the public information system- on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

GOST R 50588-2012

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

FIRE EXTINGUISHING FOAM

General technical requirements and test methods

Foaming agents for fire extinguishing. General technical requirements and test methods

Introduction date - 2012-09-01

1 area of ​​use

This standard applies to foaming agents for the preparation of aqueous solutions intended for the production of air-mechanical foam for extinguishing fires using special equipment, and foaming agents for the preparation of aqueous solutions intended for extinguishing fires, as wetting agents (hereinafter referred to as wetting agents).

2 Normative references

This standard uses normative references to the following standards:

Table 1 - Quality indicators of wetting agents and foaming agents types WA and S when using distilled and drinking water

	Meaning for		Test method
	wetting agents type WA	Type S foam concentrates
1 Appearance
× s -1 , no more
4 Dynamic viscosity, Pa× s, no more	Must be specified in the regulatory or technical document for a specific foaming agent or wetting agent
	6,5 - 8,5
	Minus 3	Minus 3
low, no more
Average, not less	Not standardized
high, no less	Same
	Not standardized
× c) (bench method)	Not standardized
Medium expansion foam at intensity (0.032 ± 0.002), dm 3 / (m 2× c)	Same

Table 2 - Quality indicators of wetting agents and foaming agents types WA and S when using hard and sea water

Name of indicator	Meaning for		Test method
	wetting agents type WA	Type S foam concentrates
1 Appearance	Homogeneous liquid without sediment and stratification
2 Density at 20 °С, kg/cm 3	Must be specified in the regulatory or technical document for a specific foaming agent or wetting agent
3 Kinematic viscosity at 20 °C, mm 2× s -1 , no more
4 Dynamic viscosity, Pa× s, no more	Must be specified in the regulatory or technical document for a specific foaming agent or wetting agent
5 pH value of the foaming agent (wetting agent)	6,5 - 8,5
6 Pour point, °С, not higher	Minus 3	Minus 3
7 Multiplicity of foam from the working solution:
low, no more
Average, not less	Not standardized
high, no less	Same
8 Stability index for low, medium and high expansion foam	Not standardized	Must be specified in the regulatory or technical document for a specific blowing agent
9 Quenching time of n-heptane at the specified intensity of the supply of the working solution, s, not more than:
Medium expansion foam at an intensity of (0.032 ± 0.002) dm 3 / (m 2× c) (bench method)	Not standardized
Medium expansion foam at an intensity of (0.032 ± 0.002) dm 3 / (m 2× c)	Same
10 Surface tension of working solution, mN/m, no more	Must be specified in the regulatory or technical document for a specific foaming agent or wetting agent
11 Wetting ability index, s, no more	Must be specified in the regulatory or technical document for a specific foaming agent or wetting agent

Table 3 - Quality indicators of foam concentrates of S/AR types; AFFF/AR, FP/AR, FFFP/AR, AFFF, AFFF/AR-LV, FP, FFFP when using distilled and potable water

Name of indicator						Test method
	type S/AR	types AFFF/AR, FP/AR, FFFP/AR
1 Appearance	Homogeneous liquid without sediment and stratification
2 Density at 20 °С, kg/cm 3
3 Kinematic viscosity at 20 °C, mm 2× s -1 , no more	Must be specified in the regulatory or technical document for a specific foaming agent
4 Dynamic viscosity, Pa× s, no more				Must be specified in the regulatory or technical document for a specific foaming agent
	6,5 - 8,5
6 Pour point, °С, not higher	Minus 3	Minus 15		Minus 15
7 Multiplicity of foam from the working solution:
low, no more
Average, not less	60 *	40 *		40 *
high, no less	200 *	200 *		200 *
8 Stability index for low, medium and high expansion foam	Must be specified in the regulatory or technical document for a specific blowing agent
9 Quenching time of n-heptane at the specified intensity of the supply of the working solution, s, not more than:
× c)
Medium expansion foam at an intensity of (0.032 ± 0.002) dm 3 / (m 2× c)	120 *		100 *		100 *
× c)	120 *		90 *		90 *
10 Re-ignition time of the model focus after extinguishing with foam, s, not less than:
Low multiplicity
Medium multiplicity			400 *		400 *
			Must be specified in the regulatory or technical document for a specific blowing agent
	Not standardized		Must be specified in the regulatory or technical document for a specific blowing agent

Table 4 - Quality indicators of foam concentrates types S / AR, AFFF / AR, FP / AR, FFFP / AR, AFFF, AFFF / AR-LV, FP, FFFP when using hard and sea water

	Value for blowing agents			Test method
	type S/AR	types AFFF/AR, FP/AR, FFFP/AR	types AFFF, AFFF/AR-LV, FP, FFFP
1 Appearance	Homogeneous liquid without sediment and stratification
2 Density at 20 °С, kg/cm 3	Should be specified in the normative or technical document for a specific blowing agent
3 Kinematic viscosity at 20 °C, mm 2× s -1 , no more	Must be specified in the regulatory or technical document for a specific foaming agent
4 Dynamic viscosity, Pa× s, no more			Must be specified in the regulatory or technical document for a specific foaming agent
5 Foaming agent pH	6,5 - 8,5
6 Pour point, °С, not higher	Minus 3	Minus 15	Minus 15
7 Multiplicity of foam from the working solution:
low, no more
Average, not less	60 *	40 *	40 *
high, no less	200 *	200 *	200 *
8 Stability index for low, medium and high expansion foam	Must be specified in the regulatory or technical document for a specific blowing agent
9 Quenching time of n-heptane at the specified intensity of the supply of the working solution, s, not more than:
Low expansion foam at an intensity of (0.059 ± 0.002) dm 3 / (m 2× c)	Must be specified in the regulatory or technical document for a specific blowing agent
Medium expansion foam at an intensity of (0.032 ± 0.002) dm 3 / (m 2× c)	120 *	120 *	120 *
High expansion foam at an intensity of (0.059 ± 0.002) dm 3 / (m 2× c)	120 *	120 *	120 *
10 Re-ignition time of the model focus after extinguishing with foam, s, not less than:
Low multiplicity	Must be specified in the regulatory or technical document for a specific blowing agent
Medium multiplicity	Same	330 *	330 *
11 Surface tension of working solution, mN/m, no more	Must be specified in the regulatory or technical document for a specific blowing agent
12 Interfacial tension of the working solution at the border with heptane, mN/m, not less than	Not standardized	Must be specified in the regulatory or technical document for a specific blowing agent
* For foaming agents that form foam of the specified multiplicity.

Drinking water with electrical conductivity (0.10 ± 0.05) S/m;

Hard water (hard water model - according to the appendix);

Sea water (sea water model - according to the application).

5.1.2 Periodic control of foam concentrates and wetting agents should be carried out according to indicators 1, 5, 7, 8, 10, 11 of tables -.

The appearance of the foaming agent is determined visually in cylinders according to GOST 1770 made of colorless glass with a capacity of 250 cm 3 in transmitted scattered light at a temperature of (20 ± 2) °C.

200 cm 3 of foam concentrate are poured into two identical cylinders and kept for (12 ± 2) hours at a temperature of (3 ± 2) ° C, and then at a temperature of (60 ± 2) ° C for (12 ± 2) hours In this case, stratification and precipitation visible to the naked eye should not be observed. For fluoroprotein foaming agents, a sediment of not more than 0.25% by volume is allowed.

5.3.1 Determination of the expansion and stability index of low and medium expansion foam

The essence of the method is to measure the mass before and after filling the foam collection container with foam, followed by calculating the foam ratio and determining its stability index.

5.3.1.1 Applied equipment, measuring instruments and solutions

To determine the expansion and stability index of low and medium expansion foam, use the installation (see figure), which includes:

Medium expansion foam generator GPS-100 (see figure ) with an atomizer with a diameter of 8.1 mm, which makes it possible to provide a volumetric flow rate of the solution (1.0 ± 0.1) dm 3 / s at a pressure on the barrel (0.60 ± 0.01 ) MPa or a fire nozzle for low expansion foam with a sprayer (see figure ), which allows to provide a volumetric flow rate of the solution (0.166 ± 0.001) dm 3 / s at a pressure on the barrel (0.58 ± 0.02) MPa;

Water pump, providing a solution volumetric flow rate of 0.16 - 1.10 dm 3 / s at a pressure on the barrel (0.58± 0.03) MPa;

A cylindrical metal container for collecting foam, with a capacity of (200 ± 1) dm 3, weighing no more than 12 kg, with a hole with a diameter of (40 ± 5) mm in the center of the bottom of the container for the expiration of the working solution. Tank Height Ratioh to its diameter d equals 1.5;

Scales with a measurement limit of not more than 50 kg and a measurement error of not more than 0.05 kg;

Measuring container for preparing a working solution of a foaming agent, with a capacity of 100 - 110 dm 3;

5.3.1.2 Test preparation

Prepare 100 dm 3 working solution of the tested foaming agent. Check the operation of the pumping unit. Measure the mass of the empty foam container.

Before each determination, the temperature of the working solution of the foaming agent is measured, which should be (20 ± 2) °C.

1 - foam generator or low expansion barrel; 2 - pressure hose; 3, 4 - a branch pipe with a manometer;
5 - water pump; 6 - suction sleeve; 7 - a container with a working solution of a foaming agent;
8 - container for collecting foam; 9 - scales

Figure 1 - Scheme of installation for determining the multiplicity and stability index
foam

1 - frame; 2 - mesh package; 3 - atomizer

Figure 2 - Medium expansion foam generator GPS-100

1 - pipe; 2 - sedative; 3 - clutch; 4 , 7 - union; 5 - atomizer; 6 - mixer;
8 - adapter; 9 - pressure head

Figure 3 - Low expansion foam fire nozzle

5.3.1.3 Conducting the test

To determine the expansion rate of medium expansion foam, the prepared working solution is fed under pressure (0.60 ± 0.01) MPa into the pressure hose, at the outlet of which the GPS-100 generator is installed. The hole at the bottom of the container is closed. After a steady stream of foam is obtained, the foam collection container is filled with foam and weighed. In this case, the filling of the entire volume of the container must be uniform, without the formation of voids. The mass of foam is determined as the difference between the masses of the filled and empty containers. The hole at the bottom of the container is opened to allow the solution to flow out.

To obtain low expansion foam, the working solution is fed to the low expansion barrel under pressure (0.60 ± 0.01) MPa. Tank filling time - (25 ± 5) s. A ruler with a measurement limit of 100 cm determines the height of the foam H with an error of up to 1 cm and calculate the volume of low expansion foamV, dm 3, according to the formula

(1)

Where H- foam height, cm;

d- diameter of the container for collecting foam, cm.

5.3.1.4 Handling results

Foam ratio Kcalculated according to the formula

Where V P - foam volume, dm 3 ;

V p - the volume of the foaming agent solution, dm 3.

The stability index of low and medium expansion foam is defined as the time it takes for 50% of the mass of the solution to be released from the foam.

5.3.2 Determination of expansion and stability index of high expansion foam

5.3.2.1 Applied equipment, measuring instruments and solutions

To determine the expansion and stability index of high expansion foam, use the installation (see figure), which includes:

1 - fan with electric drive; 2 - tap with pressure gauge; 3 - atomizer; 4 - net

Figure 4 - High expansion foam generator

A container (see figure) of a cylindrical shape with a conical bottom for collecting foam with a capacity of (500 ± 2) dm 3 and a weight of not more than 20 kg. Tank diameter - (800 ± 5) mm, vertical wall height - (1000± 5) mm. In the conical bottom of the container there is a central hole with a diameter of 3 mm. Onat a distance of 20 mm from the center of the central hole, there are eight holes with a diameter of 3 mm arranged around the circumference for liquid to flow out;

Figure 5 - Container for collecting foam

Water pump, providing a volumetric flow rate of the solution of 0.10 - 0.15 dm 3 / s at a pressure on the barrel (0.50 ± 0.05) MPa;

Scales with a weighing limit of at least 30 kg and a measurement error of not more than 0.05 kg;

Stopwatch with a measurement limit of 60 minutes and a division value of 0.2 s;

5.3.2.2 Test preparation

Prepare 100 dm 3 working solution of the tested foaming agent. Check the operation of the pumping unit. Determine the mass of the empty container for collecting foam.

Before each determination, the temperature of the working solution of the foaming agent is monitored, which should be (20 ± 2) °C.

5.3.2.3 Testing

Test conditions: air temperature 15 °C - 25 °C, atmospheric pressure 84 - 106.7 kPa, relative air humidity 40% - 80%.

To determine the expansion rate of high expansion foam, the prepared working solution is fed under pressure (0.50 ± 0.01) MPa into the pressure hose, at the outlet of which a high expansion foam generator is installed. The holes at the bottom of the container are closed. After obtaining a stable foam jet, fill the foam collection container and weigh it. In this case, there should be a uniform filling of the entire volume of the container without the formation of voids. The mass of foam is found by the difference between the masses of the filled and empty containers. The holes at the bottom of the container are opened to allow the solution to flow out. The foam ratio is calculated by the formula ().

The foam stability index is defined as the time of release from the foam of 50% of the mass of the solution.

5.3.2.4 Processing results

The arithmetic mean of three parallel determinations is taken as the test result. The allowable discrepancy between the results of the most different determinations with a confidence probability of 0.95 should be no more than 10% of the mean value.

The essence of the method is to determine the time of extinguishing n-heptane in a pan with low expansion foam at a set intensity of the supply of the working solution of the foaming agent and to determine the time of re-ignition of the fuel surface from the burning crucible introduced into the model hearth extinguished with foam.

5.4.1 Applied equipment, measuring instruments, reagents and solutions:

Round baking tray made of low strength steel, with inner diameter (1900 ± 15) mm, height (200 ± 10) mm, wall thickness (2.50 ± 0.05) mm, bottom area (2.82 ± 0.05 ) m 2 ;

Water pump, providing a volumetric flow rate of the solution (0.166 ± 0.001) dm 3 / s at a pressure on the barrel (0.58 ± 0.02) MPa;

Fire barrel of low expansion foam with a sprayer (see figure), which allows to provide a volumetric flow rate of the solution (0.166 ± 0.001) dm 3 / s at a pressure on the barrel (0.58 ± 0.02) MPa;

Re-ignition crucible, made of low strength steel, with internal diameter (295 ± 5) mm, height (130 ± 10) mm, wall thickness (2.50 ± 0.05) mm. The crucible has handles, with the help of which it is fed into a baking sheet on a pole;

Measuring container for preparing a working solution of a foaming agent, with a capacity of 100 - 110 dm 3;

Stopwatch with a measurement limit of 60 minutes and a division value of 0.2 s;

5.4.2 Preparation for testing

Test conditions:

The test is carried out outdoors. Air temperature 10 °С - 22 °С. Wind speed near the pan is not more than 1.5 m/s. Before each determination, the temperature of n-heptane and the working solution of the foaming agent is monitored, which should be (17.5 ± 2.5) °C.

Prepare 100 dm 3 working solution of the tested foaming agent. Place the tray on a flat surface of the ground. The re-ignition crucible is placed at a distance of 2.5 to 3.0 m from the pan. Check the operation of the pumping unit. The barrel is positioned at such a distance and with such an inclination that the foam enters the center of the hearth at an angle of 45 °.

5.4.3 Determining the extinguishing time of n-heptane with low expansion foam

Pour (150 ± 5) dm 3 n-heptane into a baking tray without a water cushion. In the crucible for re-ignition pour 7 dm 3 n-heptane. Ignite the fuel in the pan and the crucible. Free burning time in a baking sheet (120 ± 5) s. Serve the foam in the center of the pan for (120 ± 2) s, even if the extinguishing has come earlier than this time.

5.4.4 Determining the re-ignition time

After (60 ± 2) s after the foam supply is stopped, a burning crucible is placed in the center of the pan with extinguished fuel for re-ignition. The crucible is lowered to the bottom of the pan. When lowering the crucible, care must be taken that the foam from the pan does not extinguish the fuel in the crucible.

The time is recorded from the moment the crucible is placed in the pan until the entire area of ​​the pan is engulfed in flame.

Three parallel determinations are made. If extinguishing is successful in the first two determinations, the third is not carried out.

5.4.5 Handling results

The test result is taken as the arithmetic mean of the results of two successful parallel determinations of the extinguishing time and the re-ignition time. The allowable discrepancy between the test results with a confidence level of 0.95 should be no more than 20% of the average value. If a negative result is obtained in two out of three determinations when determining the extinguishing time or the re-ignition time, the final result is considered negative.

The essence of the method is to determine the time of extinguishing n-heptane with medium expansion foam at the established intensity of the supply of the working solution of the foaming agent in laboratory conditions.

5.5.1 Applied equipment, measuring instruments and solutions

To determine the extinguishing time with medium expansion foam, use the installation (see figure), which includes:

Foam generator that provides foam with an average expansion of 80 ± 20 at working volumetric flow rates of the solution (2.0 ± 0.2) g / s and air (160 ± 40) cm 3 / s. For the manufacture of a package of generator grids, a stainless steel grid is used with a cell side in the clear of 0.9 mm and a wire diameter of 0.2 mm;

A container with a foaming agent working solution, made of metal or polymeric material, with a capacity of at least 5 dm 3 with a neck and a screw cap;

Gas rotameter in accordance with GOST 13045, providing control of the volumetric air flow (160 ± 40) cm 3 / s;

Liquid rotameter according to GOST 13045, which provides control of the volumetric flow rate of the working solution (2.0 ± 0.2) cm 3 / s;

1 - foam generator; 2, 9 - rotameter; 3 - tank; 4, 5, 7, 8 - tap; 6 - manometer;
10 - baking sheet; 11 - fencing; 12 - retractable holder

Figure 6 - Scheme of installation for extinguishing with medium expansion foam
(bench method)

The fence for the burner and the foam generator is equipped with a window for monitoring the progress of the extinguishing, an entrance door for replacing the baking sheet and controlling the foam generator, and a retractable holder for the foam generator.

5.5.2 Test preparation

Test conditions: air temperature from 15 °С to 25 °С, pressure from 84 to 106.7 kPa, relative air humidity from 40% to 80%.

Prepare 4 dm 3 of the working solution of the tested foaming agent with a temperature of (20 ± 2) °C. The solution is poured into the tank. Air and solution are supplied to the foam generator. After 5 - 10 s after the start of the foam supply, a sample is taken into a measuring container. Fix the time of foam collection. Sampling should be carried out in such a way that the measuring container is filled evenly throughout the volume. Determine the mass of the foam by weighing the measuring container before and after the set of foam.

The solution flow rate is calculated by dividing the mass of foam by the time of filling the vessel, the volumetric air flow - by dividing the volume of foam by the time of filling the vessel. If the costs correspond to the established ones, then proceed to the test.

5.5.3 Conducting the test

After checking the operation of the foam generator, n-heptane is poured into the burner with a layer (20 ± 1) mm high. Heptane is ignited and the free burning time is maintained (180 ± 5) s. During free burning, the foam generator must be outside the flame zone. Then the foam is supplied and the foam generator is introduced into the combustion zone in such a way that the foam is supplied to the center of the pan, maintaining the set flow rates of the solution and air. Simultaneously with the input of the foam generator include a stopwatch.

The time is measured from the moment the foam begins to be fed into the pan until the combustion stops.

Three determinations are made. If extinguishing is successful in the first two determinations, the third is not carried out.

Reuse of n-heptane is unacceptable.

5.5.4 Handling results

The test result is taken as the arithmetic mean of the results of two successful parallel determinations.

The allowable discrepancy between the results of repeated determinations with a confidence probability of 0.95 should be no more than 15% of the average value.

The essence of the method is to determine the extinguishing time of n-heptane in a pan with medium expansion foam at a set intensity of the working solution supply and to determine the time of re-ignition of the fuel surface from a burning crucible brought to the model hearth extinguished with foam.

5.6.1 Applied equipment, measuring instruments, reagents and solutions

To determine the extinguishing time of n-heptane with medium expansion foam and the re-ignition time, use the installation (see figure), which includes:

Fire barrel of medium expansion foam with a sprayer (see figure), providing a volumetric flow rate of the solution (0.055 ± 0.003) dm 3 / s at a pressure on the barrel of 0.4 - 0.6 MPa;

1 - a container with a working solution of a foaming agent; 2 - pump; 3 - pipeline; 4 - sleeve;
5 - manometer; 6 - fire barrel; 7 - baking sheet; 8 - crucible

Figure 7 - Scheme of installation for extinguishing with medium expansion foam

1 - net; 2 - frame; 3 - atomizer; 4 - manometer; 5 - tap; 6 - connection head

Figure 8 - Medium expansion foam fire nozzle

A device for installing a medium expansion foam fire hose on the edge of a baking sheet;

Round baking tray made of low strength steel, with inner diameter (1480 ± 5) mm, height (150 ± 10) mm, wall thickness (2.50 ± 0.05) mm, bottom area (1.72 ± 0.01 ) m 2 ;

Water pump, providing a volumetric flow rate of the working solution of the foaming agent (0.055 ± 0.003) dm 3 / s at a pressure on the barrel from 0.4 to 0.6 MPa;

Pressure hose;

Measuring container with a capacity of 100 - 110 dm 3 for preparing a working solution of a foaming agent;

5.6.2 Test preparation

Test conditions

The test is carried out outdoors. Air temperature - from 10 °С to 22 °С, wind speed near the pan - no more than 2 m/s. Before each determination, the temperature of n-heptane and the working solution of the foaming agent is monitored, which should be (17.5 ± 2.5) °C.

Prepare 100 dm 3 working solution of the tested foaming agent. Place the tray on a flat surface of the ground. Pour into a baking sheet (30 ± 1) dm 3 of water and (55 ± 1) dm 3 of n-heptane. The barrel of medium expansion foam is installed horizontally directly on the edge of the baking sheet on the leeward side. The crucible for re-ignition is installed at a distance of 2.5 - 3 m from the baking sheet and (1.0 ± 0.1) dm 3 of fuel is poured into it. Check the operation of the installation.

5.6.3 Determining the extinguishing time of n-heptane with medium expansion foam

Fuel is lit in the pan and the crucible. The free burning time is (60 ± 5) s. For the time of free burning, the barrel is taken out of the flame zone. Turn on the pump and set the barrel on the edge of the baking sheet. When testing foam concentrates of types S/AR, AFFF/AR, FP/AR, FFFP/AR, AFFF, AFFF/AR-LV, FP, FFFP, foam is applied within (120 ± 5) s, even if extinguishing occurs earlier than this time. When testing foam concentrates of the typeS The foam supply is continued for (300 ± 5) s, even if the extinguishing occurs earlier than this time.

Record the time from the start of the foam supply until the end of combustion.

Three parallel determinations are made. If extinguishing is successful in the first two determinations, the third is not carried out.

5.6.4 Determining the re-ignition time

After stopping the supply of medium expansion foam, a burning crucible is attached to the outside of the pan with extinguished fuel for re-ignition.

Record the time from the moment the crucible is installed until the moment when the entire area of ​​the pan is engulfed in flames.

Three parallel determinations are made. If extinguishing is successful in the first two determinations, the third is not carried out.

5.6.5 Handling results

The test result for extinguishing time and re-ignition time is taken as the arithmetic mean of the results of two successful parallel determinations. The permissible discrepancy between the results of determinations with a confidence probability of 0.95 should be no more than 20% of the average value. If a negative result is obtained in two of the three determinations when determining the extinguishing time or the re-ignition time, the test result is considered negative.

The essence of the method is to determine the time of extinguishing n-heptane in a pan with high expansion foam at a specified intensity of the supply of the working solution.

5.7.1 Applied equipment, measuring instruments, reagents and solutions:

High expansion foam generator (see figure), which allows to provide a volumetric flow rate of the foam concentrate solution (0.102 ± 0.002) dm 3 / s at a barrel pressure of (0.50 ± 0.01) MPa;

Water pump, providing a volumetric flow rate of 0.10 - 0.15 dm 3 / s at a pressure on the barrel (0.50 ± 0.01) MPa;

Round baking tray made of low strength steel, with inner diameter (1480 ± 15) mm, height (150 ± 10) mm, wall thickness (2.50 ± 0.05) mm, bottom area (1.72 ± 0.01 ) m 2 ;

Foam collection screen made of mesh (low-strength steel wire diameter 0.4 - 2.0 mm, clear side of the cell 1.0 - 8.0 mm), length (2000 ± 50) mm, height (1000 ± 50) mm and width (2000 ± 50) mm;

Pressure hose;

Measuring container for preparing a working solution of a foaming agent with a capacity of 100 - 110 dm 3;

5.7.2 Preparation for testing

Test conditions

The test is carried out outdoors. Air temperature 10 °С - 22 °С, wind speed near the pan is not more than 2 m/s. Before each determination, the temperature of n-heptane and the working solution of the foaming agent is monitored, which should be (17.5 ± 2.5) °C.

Prepare 100 dm 3 working solution of the tested foaming agent. Place the tray on level ground inside the foam screen. Pour into a baking sheet (30 ± 1) dm 3 of water and (55 ± 1) dm 3 of n-heptane. Place the generator at a distance of (7.5 ± 2.5) m from the baking sheet on a cart so high that the axis of the foam generator is (0.65 ± 0.05) m above the ground (see figure). Check the operation of the installation.

1 - high expansion foam generator on a mobile platform; 2 - high expansion foam;
3 - a baking sheet with fuel; 4 - screen for collecting foam

Figure 9 - Installation scheme

5.7.3 Conducting the test

The fuel in the pan is lit. The free burning time is (60 ± 5) s. Turn on the pump. The high expansion foam generator is brought to the baking sheet at a distance of (1.0 ± 0.1) m. The foam is supplied from the generator for (120 ± 2) s, even if the extinguishing occurred earlier.

Record the time from the start of the foam supply until the end of combustion.

Three parallel determinations are made. If extinguishing is successful in the first two determinations, the third is not carried out.

5.7.4 Handling results

The test result is taken as the arithmetic mean of the results of two successful parallel extinguishing time determinations. The allowable discrepancy between the results of parallel determinations with a confidence level of 0.95 should be no more than 20% of the average value. If a negative result is obtained in two of the three determinations, the test result is considered negative.

The measurement of the surface tension of the working solution of the foaming agent or wetting agent and the interfacial tension at the boundary of the working solution with n-heptane is carried out by the “ring tear” method (De Nooy method).

5.8.1 Applied instruments, utensils, reagents and solutions:

A tensiometer is an experimental device for measuring the surface and interfacial tension of liquids with an error of no more than 0.1 mN / m (see figure). The device must automatically determine the value of surface and interfacial tension using a measuring ring based on the results of at least five determinations. The instrument must have overload protection for the weighing system, a level gauge for horizontal installation, a protective screen to prevent exposure to air vibrations and a sample temperature sensor. The horizontal platform for holding the sample cuvette must be able to move up and down to change the vertical position of the sample;

1 - measuring ring; 2 - shoulder of the measuring ring; 3 - horizontal platform of the tensiometer;
4 - the handle of the lifting mechanism of a little table; 5 - tensiometer control panel;
6 - cuvette with working solution; 7 - weight system; 8 - protective screen

Figure 10 - Diagram of a tensiometer for determining surface tension
working solutions

Measuring ring for tensiometer. Ring wire - round with a diameter of at least 0.3 mm, the lower part of the ring must have one plane without bends and roughness. The ring must be welded into a continuous circle and held on two parallel arms. The length of the arms of the measuring ring must be at least 23 mm. Ring diameter not less than 19 mm. When placed on the device, the plane of the ring must be parallel to the plane of the surface of the working solution;

A cuvette for an aqueous solution of a foaming agent or wetting agent. The cuvette is a glass container of a regular cylindrical shape with a diameter of at least 64 mm;

Measuring cylinder with a capacity of 500 cm 3 according to GOST 1770 for preparing a working solution of a foaming agent or wetting agent;

Combustible liquid - n-heptane according to GOST 25828;

5.8.2 Test preparation

The cuvette and ring must be cleaned, rinsed with distilled water and dried. The ring is additionally fired on a gas burner for 5 s and hung on the hook of the weight system of the tensiometer.

The tensiometer must be placed on a stable, vibration-free base.

Prepare solutions of foaming agents or wetting agents with a working concentration. The temperature of solutions and n-heptane should be (20.0 ± 0.2) °C. Perform device setup.

On the control panel of the tensiometer set:

Method of determination - ring;

Data on the density of the foaming agent or wetting agent solution;

Tensiometer platform lowering speed values ​​are 0.15 - 0.30 mm/s.

5.8.3 Conduct tests

Test conditions: air temperature (20.0 ± 0.2) °C, pressure 84 - 106.7 kPa, relative air humidity 40% - 80%.

The prepared working solution is poured into a cuvette. The height of the liquid column in the cuvette should be 15 - 20 mm. The cuvette with the working solution is placed on the platform of the tensiometer. Check the temperature of the solution.

Using the handle of the lifting mechanism or automatically, the platform of the tensiometer is raised so that the measuring ring is immersed in the solution and is 1 mm below the surface of the solution.

On the control panel of the tensiometer, the weight system is reset to zero, and then the surface tension measurement is started.

Measurements end automatically. On the control panel of the tensiometer, the average value of surface tension is determined, calculated from the results of at least five parallel measurements.

After measuring the surface tension, the platform of the tensiometer is lowered, and n-heptane is poured into the cuvette over the working solution to determine the interfacial tension. The height of the column of solution and n-heptane in the cuvette should be 30 - 40 mm.

Using the handle of the lifting mechanism or automatically, the platform of the tensiometer is raised so that the measuring ring is first immersed in n-heptane, and then in the working solution and is 1 mm below the surface of the solution.

On the control panel of the tensiometer indicate data on the difference in the density of the solution of the foaming agent and n-heptane.

On the control panel of the tensiometer, the weight system is reset, and then the start of the measurement of interfacial tension is started.

Measurements end automatically. On the control panel of the tensiometer, the average value of interfacial tension is determined, calculated from the results of at least five parallel measurements.

The essence of the method is to determine the wetting time of a sample of cotton fabric with a solution of a wetting agent or a foaming agent used as a wetting agent. Measure the time from the moment the sample is completely immersed in the test solution until the moment when the sample begins to sink.

5.9.1 Applied equipment, materials, solutions and utensils:

Round samples of unbleached cotton fabric with a diameter of (30 ± 1) mm, kept at a relative humidity of 65% for 3 days. The surface density of the fabric is 494 g / m 2, the number of threads per 1 cm of the length of the fabric should be 11 pieces;

A clamping device for immersing a sample of cotton fabric in a working solution (see figure). For the manufacture of fixtures, a stainless metal wire with a diameter of 2 mm is used;

Glass glass of a cylindrical form, with a diameter of 95 mm and a capacity of 1000 cm 3;

Measuring cylinders in accordance with GOST 1770 for the preparation of wetting solutions with a volume of 2000 cm 3 with a scale division of 20 cm 3 in the amount of 5 pcs.;

Stopwatch with a measurement limit of 60 minutes and a division value of 0.2 s;

Drinking or distilled water.

Figure 11 - Scheme of the clamping device for immersing a sample from
cotton fabric in the working solution

5.9.2 Test preparation

Depending on the value of the set working volumetric concentration of the wetting agent in the solution, a range for five concentrations is determined. Volume fraction of wetting agent With p,%, calculated by the formula

Where WITH slave - working volumetric concentration of the wetting agent, %;

P- definition number in the studied range 1 - 5.

Graduated cylinders are numbered from 1 to 5.

The clamp, beaker and measuring cylinders are thoroughly washed, degreased with a mixture of acetone and ethyl alcohol in equal proportions, rinsed with distilled water and wiped with filter paper.

Prepare five aqueous solutions with the established concentrations of the wetting agent. In the fifth cylinder prepare a solution with the highest concentration of the wetting agent in the amount of 2000 cm 3 . 1000 cm 3 of water and 1000 cm 3 of solution from the fifth cylinder are poured into the fourth cylinder. 1000 cm 3 of water and 1000 cm 3 of the solution from the fourth cylinder are poured into the third cylinder. Thus, dilution is continued to the minimum concentration, while the concentration of the wetting agent in each subsequent cylinder is halved. The amount of the prepared solution will be 2000 cm 3 in the first cylinder and 1000 cm 3 in the second to fifth cylinders. The water temperature during the preparation of solutions should be (28 ± 2) °C. After preparation, the solutions are cooled.

5.9.3 Testing

Test conditions: air temperature (20.0 ± 0.2) °C, pressure 84 - 106.7 kPa, relative air humidity 60% - 70%.

Tests begin with the lowest concentration of wetting agent.

700 cm 3 solution is poured into a glass. The temperature of the solution should be (20 ± 1) °C. The foam from the surface of the solution is removed with filter paper. The cotton sample is placed in the clamps of the fixture and vertically completely immersed in the solution. The support handles are installed on the edge of the glass, the clamps of the device are opened (see figure). During the experiment, every 10 s, the clamps of the device are compressed and opened to establish the vertical position of the sample deformed in the solution.

Figure 12 - Determination of wetting ability in use
distilled and drinking water

The time is measured from the moment the sample is immersed in the working solution until the moment when the sample begins to sink freely. The measured time is an indication of the wetting ability.

5.9.4 Handling results

The test result is taken as the arithmetic mean of two parallel determinations of the wetting ability index for one concentration. The allowable discrepancy between the results of parallel determinations with a confidence level of 0.95 should be no more than 20% of the average value.

Build a logarithmic dependence of the wetting ability index on the volume concentration of the wetting agent in the solution (see figure). Graphically determine the minimum volumetric concentration of the wetting agent in the working solution, at which the value of the wetting ability index is 45 s.

The result of the tests is to determine the compliance with the working volumetric concentration of the wetting agent and to determine the value of the wetting ability index. The working volume concentration of the wetting agent in the solution must not be less than the concentration at which the value of the wetting ability index is 45 s.

Figure 13 - Determination of the wetting ability index of the wetting agent

The essence of the method is to determine the wetting time of the filter made of cotton fabric with a wetting agent solution. Measure the time from the moment the test solution is poured into the hollow cylinder of the wettability index tester until the first drop appears.

5.10.1 Applied equipment, materials, measuring instruments, utensils and reagents:

Filters made of unbleached cotton fabric, cut in the form of a circle with a diameter of (30 ± 1) mm, kept at a relative humidity of 65% for 3 days. The surface density of the fabric is 494 g/m 2 , the number of threads per 1 cm of the length of the fabric is 11 pieces;

Measuring cylinders according to GOST 1770 for the preparation of wetting agent solutions with a capacity of 100 cm 3 in the amount of 5 pieces;

Beaker with a capacity of 50 cm 3 according to GOST 1770;

Device for determining the wettability index with a stand for fixing the device (see figure ). The device consists of a metal hollow cylinder and a metal drain. The inner diameter of the hollow cylinder shall be (25 ± 1) mm. A cotton filter is installed between the hollow cylinder and the drain. The hollow cylinder and drain are fixed to each other with screws;

Glass cup for collecting drops from the drain;

Stopwatch with a measurement limit of 60 minutes and a division value of 0.2 s;

Sea or hard water.

1 - hollow cylinder; 2 - screw; 3 - a plate of cotton fabric: 4 - stock; 5 - cup; 6 - tripod

Figure 14 - Device for determining the index of wetting ability

5.10.2 Test preparation

A filter made of cotton fabric is installed between the hollow cylinder and the drain of the device. The hollow cylinder and drain are fixed to each other with screws. A device for determining the wetting ability index is mounted on a tripod. A cup is placed under the drain of the device.

Depending on the value of the set working volumetric concentration of the wetting agent in the solution, a range for five concentrations is determined. The values ​​of volumetric concentrations of the wetting agent in the studied range are calculated by the formula ().

Graduated cylinders are numbered from 1 to 5. Prepare five aqueous solutions with the established concentrations of the wetting agent. In the fifth cylinder, a solution is prepared with the highest concentration of the wetting agent in the amount of 100 cm 3 . 50 cm 3 of water and 50 cm 3 of solution from the fifth cylinder are poured into the fourth cylinder. 50 cm 3 of water and 50 cm 3 of the solution from the fourth cylinder are poured into the third cylinder. Thus, dilution is continued to the minimum concentration, while the concentration of the wetting agent in each subsequent cylinder is halved. The amount of the prepared solution will be 100 cm 3 in the first cylinder and 50 cm 3 in cylinders from the second to the fifth.

The water temperature during the preparation of solutions should be (28 ± 2) °C.

5.10.3 Conducting the test

Test conditions: air temperature (20 ± 1) °С, pressure 84 - 106.7 kPa, relative air humidity 60% - 70%.

The test starts with the lowest concentration of wetting agent. Pour 10 cm 3 of the working solution into a beaker. The temperature of the solution should be (20 ± 1) °C. The solution from the beaker is poured into the hollow cylinder of the device. The solution wets the filter and passes through it into the drain. The time from the moment the solution is poured into the hollow cylinder until the first drop appears is an indicator of wetting ability.

5.10.4 Handling results

The test result is taken as the arithmetic mean of two parallel determinations of the wetting ability index for one concentration. The permissible discrepancy between the results of repeated tests with a confidence probability of 0.95 should be no more than 20% of the average value.

Build a logarithmic dependence of the wetting ability index on the concentration of the wetting agent in the solution (see figure). Graphically, the minimum concentration of the wetting agent is determined, at which the wetting ability index is the value specified in the regulatory or technical document for a specific foaming agent or wetting agent.

The working volume concentration of the wetting agent in the solution must not be less than the concentration at which the wetting ability index is the value specified in the regulatory or technical document for a specific foaming agent or wetting agent.

Figure 15 - Determination of the wetting ability index of the wetting agent
with a working volume concentration of 1%

Bibliography

Keywords: foam concentrates, wetting agents, fire extinguishing, terms and definitions, technical requirements, test methods

fire foam

As one of the most effective fire extinguishing agents, fire foam has been known for over a hundred years. The invention turned out to be so effective that until now there has not been a worthy replacement for foam in the fire business.

Foam perfectly resists the burning of motor fuels, other petroleum products and chemicals, copes with volumetric fire fighting and other complex tasks. Foam is used where the use of water is inefficient, impractical or even dangerous. foaming agent(a tool that takes part in the creation of foam) and specialized equipment is in service with firefighters who protect not only chemical and petrochemical industries, but also airfields, large warehouses and other critical facilities.

Historical reference

The history of the use of foam in the theory and practice of Russian firefighters can be counted from 1904, the year the engineer, scientist and teacher Alexander Loran received the corresponding patent. The inventor served as a school teacher in Baku. Since there were oil fields in this city, oil fires were well known to him. As a result of a series of experiments, Laurent received a stable foam created from aluminum sulfate, sodium bicarbonate and water. The bubbles of the new extinguishing agent spread without obstacles over the heavier oil and, literally blocking the oxygen, stopped the fire.

The complexity of creating such a chemical foam was the need to use multicomponent mixtures. The problem was solved a few decades later, when mixtures were invented that foamed when exposed to a stream of air.

Fire foam classification

Foam, as its name implies, is air bubbles in a film created by a liquid. Respectively, blowing agent- a substance that is used to create foam.

If we talk about the methods of classifying foam, then two main ones should be noted:

• creation method;
• multiplicity.

As noted above, according to the method of creation, the foam is divided into chemical, and obtained under the influence of air in special devices. Chemical is the result of the interaction of a certain set of components. Air-mechanical foam is the result of mixing air with the so-called foam concentrate.

Firefighters give preference to air-mechanical foam, due to its excellent fire-extinguishing characteristics, ease of handling and the ability to control the multiplicity.

Foam ratio represents the ratio of the volume of the foam concentrate (or other starting materials) to the volume of the resulting foam. By foam ratio distinguish:

• foam emulsion (coefficient less than 3);
• low expansion foam (the coefficient is in the range of 3-20);
• foam of medium expansion (the coefficient is in the range of 20-200);
• high expansion foam (coefficient greater than 200).

It is also of great importance classification of foam concentrates. These substances of synthetic origin are usually divided into two large groups:

• containing fluorine;
• containing hydrocarbons.

Each of the blowing agents has a preferred area of ​​application. By area of ​​application foam concentrates divided into:

• surface, designed to extinguish fires on the surface of liquids and on other planes;
• local-surface, which tame fire on certain limited surfaces;
• general volume, intended for injection into enclosed spaces or tanks;
• locally-volumetric, which fill the inside of the equipment, small rooms, etc.;
• combined, having a symbiosis of the characteristics of the types of foam concentrates described above.

Features of the use of fire extinguishing foam

For several decades of use and improvement of fire-extinguishing foam, the features of its application have also been determined. So, it is advisable to water burning surfaces with foam with a low level of expansion. It holds integrity well, does not allow hot gases to pass through, and reduces the temperature of the burning surface. Such foam is supplied with a powerful jet even over fairly long distances.

Medium to high expansion foam are effectively used for isolating volumes, for extinguishing fires in such volumes, for displacing polluted air from rooms, from ventilation systems and other objects. If necessary, foam is used together with other fire extinguishing agents, including powder ones. Fire foam is widely used to cover runways in the event of an emergency landing of an aircraft.

Article sent by: beetle

Question No. 1. Fundamentals of foam extinguishing: foams, foaming agents, wetting agents, their purpose, types, composition, physical and chemical properties and scope. Safety measures when working with foam concentrates.

Types of foam, their composition, physicochemical and fire-extinguishing properties,

The procedure for obtaining and scope.

Foam - a dispersed system consisting of cells - air (gas) bubbles separated by liquid films containing a foam stabilizer.

Types of foam by production method:

- chemical foam- obtained as a result of a chemical reaction of alkaline and chemical components (the released carbon dioxide foams an aqueous alkaline solution);

- air-mechanical foam- obtained by mechanical mixing of the foaming solution with air.

Physico-chemical properties of the foam:

- sustainability- the ability of the foam to retain its original properties (to resist destruction for a certain time);

- multiplicity- the ratio of the foam volume to the volume of the foaming agent solution contained in the foam;

- viscosity- the ability of the foam to spread over the surface;

- dispersion- the degree of crushing of the bubbles (the size of the bubbles);

- electrical conductivity- the ability to conduct electricity.

Fire extinguishing properties of foam:

- insulating action(foam prevents the entry of combustible vapors and gases into the combustion zone, as a result of which combustion stops);

- cooling effect(largely inherent in low expansion foam containing a large amount of liquid).

Types of foam by multiplicity:

- low expansion foam- foam ratio from 4 to 20 (obtained with SVP trunks, foam draining devices);

- medium expansion foam- foam ratio from 21 to 200 (obtained by GPS generators);

- high expansion foam- more than 200 foam expansion (obtained by forced air injection).

Application area.

Foam is widely used to extinguish fires of solid (class A fires) and liquid substances (class B fires) that do not interact with water, and, first of all, to extinguish fires of oil products.

Advantages of foam as an extinguishing agent:

Significant reduction in water consumption;

Ability to extinguish fires of large areas;

Possibility of volume extinguishing;

Possibility of subsurface extinguishing of oil products in tanks;

Increased (compared to water) wetting ability.

When extinguishing with foam, simultaneous overlapping of the entire combustion mirror is not required, since the foam is able to spread over the surface of the burning material.

Foam concentrates: purpose, classification, types, composition,

Properties, storage rules and quality control.

Foaming agent (foam concentrate) - a concentrated aqueous solution of a foam stabilizer (surfactant), which, when mixed with water, forms a working solution of a foaming agent.

Foam concentrates are designed to produce air-mechanical foam or wetting agent solutions using fire equipment, used to extinguish fires of classes A (combustion of solid substances) and B (combustion of liquid substances).

Foaming agents, depending on the chemical composition (surfactant base), are divided into: synthetic (s), fluorosynthetic (fs), protein (p), fluoroprotein (fp).

Types of foaming agents depending on the ability to form fire-extinguishing foam on standard fire equipment:

Foam concentrates for extinguishing fires with low expansion foam (foam expansion from 4 to 20);

Foam concentrates for extinguishing fires with medium expansion foam (foam expansion from 21 to 200);

Foam concentrates for extinguishing fires with high expansion foam (foam expansion more than 200).

Foam concentrates, depending on their applicability for extinguishing fires of various classes according to GOST 27331, are divided into:

Foam concentrates for extinguishing class A fires;

Foam concentrates for extinguishing class B fires.

Foaming agents, depending on the possibility of using water with a different content of inorganic salts, are divided into types:

Foam concentrates for producing fire-extinguishing foam using potable water;

Foam concentrates for producing fire-extinguishing foam using hard water;

Foam concentrates for producing fire-extinguishing foam using sea water.

Foaming agents, depending on the ability to decompose under the action of the microflora of water bodies and soils, according to GOST R 50595, are divided into: rapidly degradable, moderately degradable, slowly degradable, extremely slowly degradable.

Classes of foam concentrates for extinguishing fires according to the totality of indicators of purpose:

1 - film-forming foam concentrates designed to extinguish fires of water-insoluble combustible liquids by supplying low-expansion foam to the surface and to the oil product layer;

2 - foam concentrates designed to extinguish fires of water-insoluble combustible liquids by soft supply of low expansion foam;

3 - special-purpose foam concentrates designed to extinguish fires of water-insoluble combustible liquids by supplying medium expansion foam;

4 - general-purpose foam concentrates designed to extinguish fires of water-insoluble combustible liquids with medium expansion foam and extinguish fires of solid combustible materials with low expansion foam and an aqueous solution of a wetting agent;

5 - foam concentrates designed to extinguish fires of water-insoluble combustible liquids by supplying high expansion foam;

6 - foam concentrates designed to extinguish fires of water-insoluble and water-soluble combustible liquids.

Foam concentrates have a symbol, which indicates:

Foam class;

Type of foaming agent;

The value of the concentration of the foaming agent in the working solution;

The chemical nature of the foaming agent.

Foam concentrates of class 1, 2, 3, 4, 5 and 6 in the symbol have the index 1H, 2H, 3C, 4C, 5B and 6, respectively.

Foam concentrates of class 1 and 2, which form fire-extinguishing foam of medium and high expansion, in the symbol have the index, respectively, 1NSV and 2NSV.

Foam concentrates of class 1 and 2, which form fire-extinguishing foam of medium expansion, in the symbol have the index, respectively, 1HC and 2HC.

Foam concentrates of class 1 and 2, which form fire-extinguishing high-expansion foam, have the index 1NVi and 2NV, respectively, in the symbol.

Class 3 foam concentrates that form fire-extinguishing high-expansion foam have the index 3CB in the symbol.

If a class 6 foam concentrate is capable of forming fire-extinguishing foam of low, medium and high expansion, its symbol indicates the corresponding index H, C, B. The absence of an appropriate index means that the foam concentrate is not recommended for extinguishing fires with foam of this expansion.

When the manufacturer recommends using a class 6 foaming agent when extinguishing water-insoluble and water-soluble combustible liquids with different concentrations, its symbol indicates the concentration of the foaming agent in the working solution when extinguishing water-insoluble and water-soluble combustible liquids.

An example of a foam concentrate symbol 2 NSV - 6 fs

Checking the quality of foam concentrates and determining the foam ratio.

To determine the foam ratio, a 2-6% solution of a foaming agent is poured into a glass graduated cylinder with a capacity of 1000 cm 3, closed with a cork and, holding it in a horizontal position with both hands, shake it in the direction of the longitudinal axis for 30 s. After shaking, the cylinder is placed on the table, the cork is removed and the volume of foam formed is counted. The ratio of the resulting volume of foam to the volume of the solution expresses the multiplicity of the foam. Sustainability foam depends on the time during which the foam, obtained by the method of determining the multiplicity, is destroyed by 2/5 of the original volume.

The quality indicators of foam concentrates during their storage in fire departments and at protected facilities equipped with fire extinguishing systems are checked after the expiration of the warranty period, and then at least 1 time in 6 months (PO-3NP, Foretol, "Universal" - at least 1 time per 12 months). The analysis of indicators is carried out in accredited organizations in accordance with GOST R 50588-93 “Foam concentrates for extinguishing fires. General technical requirements and test methods". A decrease in the value of indicators below the established norms by 20% is the basis for the write-off or regeneration (restoration of the original properties) of the foam concentrate.

Calculations of forces and means are performed in the following cases:

• when determining the required amount of forces and means to extinguish a fire;
• in the operational-tactical study of the object;
• when developing plans for extinguishing fires;
• in the preparation of fire-tactical exercises and classes;
• when carrying out experimental work to determine the effectiveness of extinguishing agents;
• in the process of investigating a fire to assess the actions of the RTP and units.

Calculation of forces and means for extinguishing fires of solid combustible substances and materials with water (spreading fire)

• • characteristics of the object (geometric dimensions, the nature of the fire load and its placement on the object, the location of water sources relative to the object);
  • the time from the moment of the fire to the notification of it (depends on the availability of the type of security equipment, communication and signaling equipment at the facility, the correctness of the actions of the persons who discovered the fire, etc.);
  • linear speed of fire propagation Vl;
  • forces and means provided for by the schedule of departures and the time of their concentration;
  • intensity of supply of fire extinguishing agents Itr.

1) Determining the time of fire development at various points in time.

The following stages of fire development are distinguished:

• 1, 2 stages free development of a fire, and at stage 1 ( t up to 10 min) the linear velocity of propagation is taken equal to 50% of its maximum value (table) characteristic for this category of objects, and from a time point of more than 10 min it is taken equal to the maximum value;
• 3 stage is characterized by the beginning of the introduction of the first trunks to extinguish the fire, as a result of which the linear speed of the fire spread decreases, therefore, in the time interval from the moment the first trunks are introduced until the moment the fire spread is limited (the moment of localization), its value is taken equal to 0,5 V l . At the time of fulfillment of localization conditions V l = 0 .
• 4 stage - fire suppression.

t St. = t update + t message + t Sat + t sl + t br (min.), where

• tSt.- the time of free development of the fire at the time of the arrival of the unit;
• tupdate – time of fire development from the moment of its occurrence to the moment of its detection ( 2 minutes.- in the presence of APS or AUPT, 2-5 min.- with 24 hour service 5 minutes.- in all other cases);
• tmessage- the time of reporting a fire to the fire brigade ( 1 min.– if the phone is in the duty room, 2 minutes.– if the phone is in another room);
• tSat= 1 min.- the time of collection of personnel on alarm;
• tsl- the time of the fire department ( 2 minutes. for 1 km);
• tbr- combat deployment time (3 minutes when applying the 1st barrel, 5 minutes in other cases).

2) Determination of distance R passed by the combustion front during the time t .

at tSt.≤ 10 min:R = 0,5 Vl · tSt.(m);

at tcenturies> 10 min.:R = 0,5 Vl · 10 + Vl · (tcenturies – 10)= 5 Vl + Vl· (tcenturies – 10) (m);

at tcenturies < t* ≤ tlok : R = 5 Vl + Vl· (tcenturies – 10) + 0,5 Vl· (t* – tcenturies) (m).

• Where t St. - time of free development,
• t centuries - the time at the time of the introduction of the first trunks for extinguishing,
• t lok - time at the time of localization of the fire,
• t * - the time between the moments of localization of the fire and the introduction of the first trunks for extinguishing.

3) Determination of the fire area.

fire area S p - this is the area of ​​the projection of the combustion zone on a horizontal or (less often) on a vertical plane. When burning on several floors, the total fire area on each floor is taken as the fire area.

Fire perimeter P p is the perimeter of the fire area.

Fire front F p is the part of the fire perimeter in the direction(s) of combustion propagation.

To determine the shape of the fire area, you should draw a diagram of the object on a scale and set aside the distance from the place of fire on the scale R passed by fire in all possible directions.

In this case, it is customary to distinguish three options for the shape of the fire area:

• circular (Fig. 2);
• corner (Fig. 3, 4);
• rectangular (Fig. 5).

When predicting the development of a fire, it should be taken into account that the shape of the fire area can change. So, when the flame front reaches the enclosing structure or the edge of the site, it is considered that the fire front straightens and the shape of the fire area changes (Fig. 6).

a) The area of ​​fire in a circular form of fire development.

SP= k · p · R 2 (m 2),

• Where k = 1 - with a circular form of fire development (Fig. 2),
• k = 0,5 - with a semicircular form of fire development (Fig. 4),
• k = 0,25 - with an angular form of fire development (Fig. 3).

b) The area of ​​fire with a rectangular form of fire development.

SP= n b · R (m 2),

• Where n– the number of fire development directions,
• b- the width of the room.

c) The fire area in the combined form of fire development (Fig. 7)

SP = S 1 + S 2 (m 2)

a) The fire extinguishing area along the perimeter with a circular form of fire development.

S t = kp(R 2 - r 2) = kph t (2 R - h t) (m 2),

• Where r = R – h T ,
• h T - fire extinguishing depth of barrels (for hand-held barrels - 5 m, for gun monitors - 10 m).

b) Fire extinguishing area along the perimeter with a rectangular form of fire development.

ST= 2 hT· (a + b – 2 hT) (m 2) - around the perimeter of the fire ,

Where A And b are the length and width of the fire front, respectively.

ST = n b hT (m 2) - along the front of a spreading fire ,

Where b And n - respectively, the width of the room and the number of directions for the supply of trunks.

5) Determination of the required water consumption for fire extinguishing.

QTtr = SP · Itr – atS p ≤S t (l/s) orQTtr = ST · Itr – atS p >S t (l/s)

The intensity of the supply of fire extinguishing agents I tr - this is the amount of fire extinguishing agent supplied per unit of time per unit of the calculated parameter.

There are the following types of intensity:

Linear - when a linear parameter is taken as a design parameter: for example, a front or a perimeter. Units of measurement – ​​l/s∙m. Linear intensity is used, for example, when determining the number of barrels for cooling burning and adjacent to burning tanks with oil products.

superficial - when the fire extinguishing area is taken as the design parameter. Units of measurement - l / s ∙ m 2. Surface intensity is used most often in fire extinguishing practice, since in most cases water is used to extinguish fires, which extinguishes the fire on the surface of burning materials.

Volumetric - when the volume of quenching is taken as the design parameter. Units of measurement - l / s ∙ m 3. Volumetric intensity is mainly used in volumetric fire extinguishing, for example, with inert gases.

Required I tr - the amount of fire extinguishing agent that must be supplied per unit of time per unit of the calculated extinguishing parameter. The required intensity is determined on the basis of calculations, experiments, statistical data on the results of extinguishing real fires, etc.

Actual I f - the amount of fire extinguishing agent that is actually supplied per unit of time per unit of the calculated extinguishing parameter.

6) Determination of the required number of barrels for extinguishing.

A)NTst = QTtr / qTst- according to the required water flow,

b)NTst\u003d R n / R st- around the perimeter of the fire,

R p - part of the perimeter, on the extinguishing of which trunks are introduced

R st \u003dqst / Itr ∙ hT- part of the fire perimeter, which is extinguished with one barrel. P = 2 · p L (circumference), P = 2 · a + 2 b (rectangle)

V) NTst = n (m + A) – in warehouses with rack storage (Fig. 11) ,

• Where n - the number of directions for the development of a fire (the introduction of trunks),
• m – number of passages between burning racks,
• A - the number of passages between the burning and neighboring non-burning racks.

7) Determination of the required number of compartments for supplying trunks for extinguishing.

NTotd = NTst / nst otd ,

Where n st otd - the number of trunks that one branch can file.

8) Determination of the required water flow for the protection of structures.

Qhtr = Sh · Ihtr(l/s),

• Where S h – area to be protected (ceilings, coverings, walls, partitions, equipment, etc.),
• I h tr = (0,3-0,5) I tr – intensity of water supply to protection.

9) Determination of the required number of shafts for the protection of structures.

Nhst = Qhtr / qhst ,

Also, the number of barrels is often determined without analytical calculation for tactical reasons, based on the location of the barrels and the number of objects to be protected, for example, one fire monitor for each farm, for each adjacent room along the RS-50 barrel.

10) Determination of the required number of compartments for supplying trunks to protect structures.

Nhotd = Nhst / nst otd

11) Determination of the required number of compartments for other work (evacuation of people, material values, opening and dismantling of structures).

Nlotd = Nl / nl otd , Nmtsotd = Nmts / nmts otd , NSunotd = SSun / SSun otd

12) Determination of the total required number of branches.

Ncommonotd = NTst + Nhst + Nlotd + Nmtsotd + NSunotd

Based on the result obtained, the RTP concludes that the forces and means involved in extinguishing the fire are sufficient. If there are not enough forces and means, then the RTP makes a new calculation at the time of the arrival of the last unit at the next increased number (rank) of the fire.

13) Comparison of actual water consumption Q f for extinguishing, protection and water loss of the network Q waters fire water supply

Qf = NTst· qTst+ Nhst· qhst ≤ Qwaters

14) Determination of the number of AC installed on water sources to supply the estimated water flow.

Not all the equipment that arrives at the fire is installed on the water sources, but such an amount that would ensure the supply of the estimated flow, i.e.

N AC = Q tr / 0,8 Q n ,

Where Q n – pump flow, l/s

Such an optimal flow rate is checked according to the accepted combat deployment schemes, taking into account the length of the hose lines and the estimated number of barrels. In any of these cases, if conditions permit (in particular, the pump-hose system), the combat crews of the arriving subunits should be used to work from vehicles already installed on the water sources.

This will not only ensure the use of equipment at full capacity, but also accelerate the introduction of forces and means to extinguish the fire.

Depending on the situation on the fire, the required flow rate of the fire extinguishing agent is determined for the entire area of ​​the fire or for the area of ​​fire extinguishing. Based on the result obtained, the RTP can draw a conclusion about the sufficiency of the forces and means involved in extinguishing the fire.

Calculation of forces and means for extinguishing fires with air-mechanical foam on the area

(not spreading fires or conditionally leading to them)

Initial data for the calculation of forces and means:

• fire area;
• the intensity of the supply of the foaming agent solution;
• intensity of water supply for cooling;
• estimated extinguishing time.

In case of fires in tank farms, the area of ​​the liquid surface of the tank or the largest possible area of ​​the spill of flammable liquids during fires on aircraft is taken as the design parameter.

At the first stage of hostilities, burning and neighboring tanks are cooled.

1) The required number of barrels to cool the burning tank.

N zg stv = Q zg tr / q stv = n ∙ π ∙ D mountains ∙ I zg tr / q stv , but not less than 3 trunks,

Izgtr= 0.8 l/s ∙ m - the required intensity for cooling the burning tank,

Izgtr= 1.2 l/s ∙ m - the required intensity for cooling a burning tank in case of fire,

Tank cooling W cut ≥ 5000 m3 and it is more expedient to carry out fire monitors.

2) The required number of barrels to cool the adjacent non-burning tank.

N zs stv = Q zs tr / q stv = n ∙ 0,5 ∙ π ∙ D SOS ∙ I zs tr / q stv , but not less than 2 trunks,

Izstr = 0.3 l/s ∙ m - the required intensity for cooling the adjacent non-burning tank,

n- the number of burning or neighboring tanks, respectively,

Dmountains, DSOS is the diameter of the burning or neighboring tank, respectively (m),

qstv– performance of one (l / s),

Qzgtr, Qzstr– required water flow for cooling (l/s).

3) Required number of GPS N gps to extinguish a burning tank.

N gps = S P ∙ I r-or tr / q r-or gps (PC.),

SP- fire area (m 2),

Ir-ortr- the required intensity of the supply of the foam concentrate solution for extinguishing (l / s ∙ m 2). At t vsp ≤ 28 about C I r-or tr \u003d 0.08 l / s ∙ m 2, at t vsp > 28 about C I r-or tr \u003d 0.05 l / s ∙ m 2 (See Appendix No. 9)

qr-orgps – productivity of HPS in terms of foaming agent solution (l/s).

4) Required amount of foam concentrate W By to extinguish the tank.

W By = N gps ∙ q By gps ∙ 60 ∙ τ R ∙ Kz (l),

τ R= 15 minutes - estimated extinguishing time when applying the VMP from above,

τ R= 10 minutes is the estimated extinguishing time when the VMP is supplied under the fuel layer,

K z= 3 - safety factor (for three foam attacks),

qBygps- productivity of HPS in terms of foaming agent (l/s).

5) Required amount of water W V T to extinguish the tank.

W V T = N gps ∙ q V gps ∙ 60 ∙ τ R ∙ Kz (l),

qVgps– HPS performance in terms of water (l/s).

6) Required amount of water W V h for tank cooling.

W V h = N h stv ∙ q stv ∙ τ R ∙ 3600 (l),

Nhstv is the total number of shafts for cooling tanks,

qstv– productivity of one fire barrel (l/s),

τ R= 6 hours - estimated cooling time for ground tanks from mobile fire fighting equipment (SNiP 2.11.03-93),

τ R= 3 hours - estimated cooling time of underground tanks from mobile fire fighting equipment (SNiP 2.11.03-93).

7) The total amount of water required for cooling and extinguishing tanks.

WVcommon = WVT + WVh(l)

8) Estimated time of occurrence of a possible release T of oil products from a burning tank.

T = ( H – h ) / ( W + u + V ) (h), where

H is the initial height of the combustible liquid layer in the tank, m;

h is the height of the bottom (bottom) water layer, m;

W - linear speed of heating of a combustible liquid, m/h (table value);

u - linear burnout rate of a combustible liquid, m/h (table value);

V - linear rate of level decrease due to pumping out, m/h (if pumping is not performed, then V = 0 ).

Extinguishing fires in rooms with air-mechanical foam by volume

In case of fires in the premises, they sometimes resort to extinguishing the fire in a volumetric way, i.e. fill the entire volume with medium-expansion air-mechanical foam (ship holds, cable tunnels, basements, etc.).

When applying VMP to the volume of the room, there must be at least two openings. VMP is supplied through one opening, and through the other, smoke and excess air pressure are displaced, which contributes to a better promotion of VMP in the room.

1) Determination of the required amount of HPS for volumetric quenching.

N gps = W pom K r / q gps ∙ t n , Where

W pom - the volume of the room (m 3);

K p = 3 - coefficient taking into account the destruction and loss of foam;

q gps - foam consumption from the HPS (m 3 / min.);

t n = 10 min - the standard time for extinguishing a fire.

2) Determination of the required amount of foaming agent W By for bulk quenching.

WBy = Ngps ∙ qBygps ∙ 60 ∙ τ R∙ Kz(l),

Sleeve capacity

Application No. 1

Throughput of one rubberized sleeve 20 meters long depending on diameter

Capacity, l/s	Sleeve diameter, mm
	51	66	77	89	110	150
	10,2	17,1	23,3	40,0	–	–

Application № 2

Resistance values ​​of one pressure hose 20 m long

Sleeve type	Sleeve diameter, mm
	51	66	77	89	110	150
Rubberized	0,15	0,035	0,015	0,004	0,002	0,00046
Non-rubberized	0,3	0,077	0,03	–	–	–

Application № 3

The volume of one sleeve 20 m long

Application No. 4

Geometric characteristics of the main types steel vertical tanks (RVS).

No. p / p	tank type	Tank height, m	Tank diameter, m	Fuel mirror area, m 2	Tank perimeter, m
1	RVS-1000	9	12	120	39
2	RVS-2000	12	15	181	48
3	RVS-3000	12	19	283	60
4	RVS-5000	12	23	408	72
5	RVS-5000	15	21	344	65
6	RVS-10000	12	34	918	107
7	RVS-10000	18	29	637	89
8	RVS-15000	12	40	1250	126
9	RVS-15000	18	34	918	107
10	RVS-20000	12	46	1632	143
11	RVS-20000	18	40	1250	125
12	RVS-30000	18	46	1632	143
13	RVS-50000	18	61	2892	190
14	RVS-100000	18	85,3	5715	268
15	RVS-120000	18	92,3	6691	290

Application No. 5

Linear velocities of combustion propagation during fires at facilities.

Object name	Linear speed of propagation of combustion, m/min
Administrative buildings	1,0…1,5
Libraries, archives, book depositories	0,5…1,0
Residential buildings	0,5…0,8
Corridors and galleries	4,0…5,0
Cable structures (cable burning)	0,8…1,1
Museums and exhibitions	1,0…1,5
Printing houses	0,5…0,8
Theaters and Palaces of Culture (stages)	1,0…3,0
Combustible coatings for large workshops	1,7…3,2
Combustible roof and attic structures	1,5…2,0
Refrigerators	0,5…0,7
Woodworking enterprises:
Sawmills (buildings I, II, III CO)	1,0…3,0
The same, buildings of IV and V degrees of fire resistance	2,0…5,0
Dryers	2,0…2,5
Procurement workshops	1,0…1,5
Plywood production	0,8…1,5
Premises of other workshops	0,8…1,0
Forest areas (wind speed 7…10 m/s, humidity 40%)
Pine	up to 1.4
Elnik	up to 4.2
Schools, medical institutions:
Buildings I and II degrees of fire resistance	0,6…1,0
Buildings III and IV degrees of fire resistance	2,0…3,0
Transport objects:
Garages, tram and trolleybus depots	0,5…1,0
Repair halls of hangars	1,0…1,5
Warehouses:
textile products	0,3…0,4
Paper rolls	0,2…0,3
Rubber products in buildings	0,4…1,0
The same in stacks in an open area	1,0…1,2
rubber	0,6…1,0
Inventory assets	0,5…1,2
Round timber in stacks	0,4…1,0
Lumber (boards) in stacks at a moisture content of 16 ... 18%	2,3
Peat in piles	0,8…1,0
Flax fiber	3,0…5,6
Rural settlements:
Residential area with dense building with buildings of the V degree of fire resistance, dry weather	2,0…2,5
Thatched roofs of buildings	2,0…4,0
Litter in livestock buildings	1,5…4,0

Application No. 6

Intensity of water supply when extinguishing fires, l / (m 2 .s)

1. Buildings and structures
Administrative buildings:
I-III degree of fire resistance	0.06
IV degree of fire resistance	0.10
V degree of fire resistance	0.15
basements	0.10
attic space	0.10
Hospitals	0.10
2. Residential houses and outbuildings:
I-III degree of fire resistance	0.06
IV degree of fire resistance	0.10
V degree of fire resistance	0.15
basements	0.15
attic space	0.15
3. Livestock buildings:
I-III degree of fire resistance	0.15
IV degree of fire resistance	0.15
V degree of fire resistance	0.20
4. Cultural and entertainment institutions (theaters, cinemas, clubs, palaces of culture):
scene	0.20
auditorium	0.15
utility rooms	0.15
Mills and elevators	0.14
Hangars, garages, workshops	0.20
locomotive, wagon, tram and trolleybus depots	0.20
5. Industrial buildings, sites and workshops:
I-II degree of fire resistance	0.15
III-IV degree of fire resistance	0.20
V degree of fire resistance	0.25
paint shops	0.20
basements	0.30
attic space	0.15
6. Combustible coverings of large areas
when extinguishing from below inside the building	0.15
when extinguishing outside from the side of the coating	0.08
when extinguishing outside with a developed fire	0.15
Buildings under construction	0.10
Trade enterprises and warehouses	0.20
Refrigerators	0.10
7. Power plants and substations:
cable tunnels and mezzanines	0.20
machine rooms and boiler rooms	0.20
fuel supply galleries	0.10
transformers, reactors, oil switches*	0.10
8. Hard materials
paper loosened	0.30
Wood:
balance at humidity, %:
40-50	0.20
less than 40	0.50
lumber in stacks within the same group at humidity,%:
8-14	0.45
20-30	0.30
over 30	0.20
round wood in stacks within one group	0.35
wood chips in piles with a moisture content of 30-50%	0.10
Rubber, rubber and rubber products	0.30
Plastics:
thermoplastics	0.14
thermoplastics	0.10
polymer materials	0.20
textolite, carbolite, plastic waste, triacetate film	0.30
Cotton and other fibrous materials:
open warehouses	0.20
closed warehouses	0.30
Celluloid and products made from it	0.40
Pesticides and fertilizers	0.20

* Supply of finely sprayed water.

Tactical and technical indicators of foam supply devices

Foam dispenser	Pressure at the device, m	Solution concentration, %	Consumption, l / s			Foam ratio	Foam production, m3/min (l/s)	Foam supply range, m
			water	BY	software solutions
PLSK-20 P	40-60	6	18,8	1,2	20	10	12	50
PLSK-20 S	40-60	6	21,62	1,38	23	10	14	50
PLSK-60 S	40-60	6	47,0	3,0	50	10	30	50
SVP	40-60	6	5,64	0,36	6	8	3	28
SVP(E)-2	40-60	6	3,76	0,24	4	8	2	15
SVP(E)-4	40-60	6	7,52	0,48	8	8	4	18
SVP-8(E)	40-60	6	15,04	0,96	16	8	8	20
GPS-200	40-60	6	1,88	0,12	2	80-100	12 (200)	6-8
GPS-600	40-60	6	5,64	0,36	6	80-100	36 (600)	10
GPS-2000	40-60	6	18,8	1,2	20	80-100	120 (2000)	12

Linear rate of burnout and heating of hydrocarbon liquids

Name of combustible liquid	Linear burnout rate, m/h	Linear fuel heating rate, m/h
Petrol	Up to 0.30	Up to 0.10
Kerosene	Up to 0.25	Up to 0.10
Gas condensate	Up to 0.30	Up to 0.30
Diesel fuel from gas condensate	Up to 0.25	Up to 0.15
Mixture of oil and gas condensate	Up to 0.20	Up to 0.40
Diesel fuel	Up to 0.20	Up to 0.08
Oil	Up to 0.15	Up to 0.40
fuel oil	Up to 0.10	Up to 0.30

Note: with an increase in wind speed up to 8-10 m/s, the burn-out rate of a combustible liquid increases by 30-50%. Crude oil and fuel oil containing emulsified water may burn out at a faster rate than indicated in the table.

Changes and additions to the Guidelines for extinguishing oil and oil products in tanks and tank farms

(information letter of the GUGPS dated 19.05.00 No. 20/2.3/1863)

Table 2.1. Normative rates of supply of medium expansion foam for extinguishing fires of oil and oil products in tanks

Note: For oil with gas condensate impurities, as well as for oil products obtained from gas condensate, it is necessary to determine the standard intensity in accordance with the current methods.

Table 2.2. Normative intensity of low-expansion foam supply for extinguishing oil and oil products in tanks*

No. p / p	Type of oil product	Normative intensity of the foam solution supply, l m 2 s '
		Fluorine-containing blowing agents “non-film-forming”		Fluorosynthetic “film-forming” blowing agents		Fluoroprotein "film-forming" blowing agents
		to the surface	into layer	to the surface	into layer	to the surface	into layer
1	Oil and oil products with T flash 28 ° C and below	0,08	–	0,07	0,10	0,07	0,10
2	Oil and oil products with Тsp over 28 °С	0,06	–	0,05	0,08	0,05	0,08
3	Stable gas condensate	0,12	–	0,10	0,14	0,10	0,14

The main indicators characterizing the tactical capabilities of fire departments

The fire extinguishing leader must not only know the capabilities of the units, but also be able to determine the main tactical indicators:

;
• possible area of ​​extinguishing with air-mechanical foam;
• possible volume of extinguishing with medium expansion foam, taking into account the stock of foam concentrate available on the vehicle;
• maximum distance for the supply of fire extinguishing agents.

Calculations are given according to the Handbook of the head of fire extinguishing (RTP). Ivannikov V.P., Klyus P.P., 1987

Determining the tactical capabilities of the unit without installing a fire truck on a water source

1) Definition formula for running time of water shafts from the tanker:

tslave= (V c -N p V p) /N st Q st 60(min.),

N p =k· L/ 20 = 1.2L / 20 (PC.),

• Where: tslave- operating time of the trunks, min.;
• V c- the volume of water in the tank, l;
• N p- number of hoses in the main and working lines, pcs.;
• V p- the volume of water in one sleeve, l (see appendix);
• N st– number of water trunks, pcs.;
• Q st- water consumption from trunks, l / s (see appendix);
• k- coefficient taking into account the unevenness of the terrain ( k= 1.2 - standard value),
• L- distance from the place of fire to the fire truck (m).

In addition, we draw your attention to the fact that in the RTP reference book Tactical capabilities of fire departments. Terebnev V.V., 2004 in section 17.1, exactly the same formula is given, but with a coefficient of 0.9: Twork = (0.9Vc - Np Vp) / Nst Qst 60 (min.)

2) Definition the formula for the possible area of ​​extinguishing with water STfrom the tanker:

ST= (V c -N p V p) / J trtcalc60(m 2),

• Where: J tr- the required intensity of water supply for extinguishing, l / s m 2 (see appendix);
• tcalc= 10 min. - estimated extinguishing time.

3) Definition foam dispenser operating time formula from the tanker:

tslave= (V r-ra -N p V p) /N gps Q gps 60 (min.),

• Where: V r-ra- the volume of an aqueous solution of a foaming agent obtained from the filling tanks of a fire engine, l;
• N gps– number of HPS (SVP), pcs;
• Q gps- consumption of a foaming agent solution from the HPS (SVP), l / s (see appendix).

To determine the volume of an aqueous solution of a foaming agent, you need to know how much water and foaming agent will be consumed.

K B \u003d 100-C / C \u003d 100-6 / 6 \u003d 94 / 6 \u003d 15.7- the amount of water (l) per 1 liter of foam concentrate for the preparation of a 6% solution (to obtain 100 liters of a 6% solution, 6 liters of foam concentrate and 94 liters of water are needed).

Then the actual amount of water per 1 liter of foam concentrate is:

K f \u003d V c / V by ,

• Where V c- the volume of water in the tank of a fire truck, l;
• V by- the volume of the foaming agent in the tank, l.

if K f< К в, то V р-ра = V ц / К в + V ц (l) - water is completely consumed, and part of the foam concentrate remains.

if K f > K in, then V r-ra \u003d V by K in + V by(l) - the foaming agent is completely consumed, and part of the water remains.

4) Definition of possible flammable liquid and liquid liquid quenching area formula air-mechanical foam:

S t \u003d (V r-ra -N p V p) / J trtcalc60(m 2),

• Where: S t- extinguishing area, m 2;
• J tr- the required intensity of the supply of the software solution for extinguishing, l / s m 2;

At t vsp ≤ 28 about C – J tr \u003d 0.08 l / s ∙ m 2, at t vsp > 28 about C – J tr \u003d 0.05 l / s ∙ m 2.

tcalc= 10 min. - estimated extinguishing time.

5) Definition volume formula for air-mechanical foam received from AC:

V p \u003d V p-ra K(l),

• Where: V p– volume of foam, l;
• TO- foam ratio;

6) Definition of the possible extinguishing volume of air-mechanical foam:

V t \u003d V p / K s(l, m 3),

• Where: V t– volume of fire extinguishing;
• K z = 2,5–3,5 – foam safety factor, which takes into account the destruction of the HFMP due to high temperature and other factors.

Examples of problem solving

Example #1. Determine the operating time of two trunks B with a nozzle diameter of 13 mm at a head of 40 meters, if one sleeve d 77 mm is laid before the branching, and the working lines consist of two sleeves d 51 mm from AC-40 (131) 137A.

Solution:

t= (V c -N r V r) /N st Q st 60 \u003d 2400 - (1 90 + 4 40) / 2 3.5 60 \u003d 4.8 min.

Example #2. Determine the operating time of the GPS-600 if the pressure at the GPS-600 is 60 m, and the working line consists of two hoses with a diameter of 77 mm from AC-40 (130) 63B.

Solution:

K f \u003d V c / V by \u003d 2350/170 \u003d 13.8.

K f = 13.8< К в = 15,7 for 6% solution

V solution \u003d V c / K in + V c \u003d 2350 / 15.7 + 2350» 2500 l.

t= (V r-ra -N p V p) /N gps Q gps 60 \u003d (2500 - 2 90) / 1 6 60 \u003d 6.4 min.

Example #3 Determine the possible fire extinguishing area for VMP gasoline of medium expansion from AC-4-40 (Ural-23202).

Solution:

1) Determine the volume of the aqueous solution of the foaming agent:

K f \u003d V c / V by \u003d 4000/200 \u003d 20.

K f \u003d 20\u003e K in \u003d 15.7 for a 6% solution,

V solution \u003d V by K in + V by \u003d 200 15.7 + 200 \u003d 3140 + 200 \u003d 3340 l.

2) Determine the possible extinguishing area:

S t \u003d V r-ra / J trtcalc60 \u003d 3340 / 0.08 10 60 \u003d 69.6 m 2.

Example #4 Determine the possible volume of extinguishing (localization) of a fire with medium expansion foam (K = 100) from AC-40 (130) 63b (see example No. 2).

Solution:

VP = Vr-raK \u003d 2500 100 \u003d 250000 l \u003d 250 m 3.

Then the volume of quenching (localization):

VT = VP/ K s \u003d 250/3 \u003d 83 m 3.

Determination of the tactical capabilities of the unit with the installation of a fire truck on a water source

Rice. 1. Scheme of water supply to pumping

Distance in sleeves (pieces)	Distance in meters
1) Determination of the maximum distance from the place of fire to the head fire truck N Goal ( L Goal ).
N mm ( L mm ) working in pumping (the length of the pumping stage).
N st
4) Determining the total number of fire trucks to pump N auth
5) Determination of the actual distance from the place of fire to the head fire truck N f Goal ( L f Goal ).

• H n = 90÷100 m - pressure on the AC pump,
• H unfold = 10 m - pressure loss in the branching and working hose lines,
• H st = 35÷40 m - pressure in front of the barrel,
• H in ≥ 10 m - pressure at the inlet to the pump of the next pumping stage,
• Z m - the greatest height of ascent (+) or descent (-) of the terrain (m),
• Z st - the maximum height of lifting (+) or lowering (-) trunks (m),
• S - resistance of one fire hose,
• Q - total water consumption in one of the two busiest main hose lines (l / s),
• L – distance from the water source to the place of fire (m),
• N hands - distance from the water source to the place of fire in the sleeves (pcs.).

Example: To extinguish a fire, it is necessary to supply three trunks B with a nozzle diameter of 13 mm, the maximum height of the trunks is 10 m. The nearest water source is a pond located at a distance of 1.5 km from the fire site, the elevation of the area is uniform and is 12 m. Determine the number of tank trucks AC − 40(130) for pumping water to extinguish a fire.

Solution:

1) We adopt the method of pumping from pump to pump along one main line.

2) We determine the maximum distance from the place of fire to the head fire truck in the sleeves.

N GOAL \u003d / SQ 2 \u003d / 0.015 10.5 2 \u003d 21.1 \u003d 21.

3) We determine the maximum distance between fire trucks operating in pumping, in the sleeves.

N MP \u003d / SQ 2 \u003d / 0.015 10.5 2 \u003d 41.1 \u003d 41.

4) We determine the distance from the water source to the place of fire, taking into account the terrain.

N P \u003d 1.2 L / 20 \u003d 1.2 1500 / 20 \u003d 90 sleeves.

5) Determine the number of pumping stages

N STUP \u003d (N R - N GOL) / N MP \u003d (90 - 21) / 41 \u003d 2 steps

6) We determine the number of fire trucks for pumping.

N AC \u003d N STUP + 1 \u003d 2 + 1 \u003d 3 tank trucks

7) We determine the actual distance to the head fire truck, taking into account its installation closer to the fire site.

N GOL f \u003d N R - N STUP N MP \u003d 90 - 2 41 \u003d 8 sleeves.

Therefore, the lead vehicle can be brought closer to the fire site.

Methodology for calculating the required number of fire trucks for the supply of water to the place of fire extinguishing

If the building is combustible, and the water sources are at a very great distance, then the time spent on laying the hose lines will be too long, and the fire will be short-lived. In this case, it is better to bring water by tank trucks with a parallel organization of pumping. In each specific case, it is necessary to solve a tactical problem, taking into account the possible scale and duration of the fire, the distance to water sources, the speed of concentration of fire trucks, hose trucks and other features of the garrison.

AC water consumption formula

(min.) – time of AC water consumption at the place of fire extinguishing;

• L is the distance from the place of fire to the water source (km);
• 1 - the minimum number of AC in the reserve (can be increased);
• V movement is the average speed of movement of the AC (km/h);
• Wcis is the volume of water in the AC (l);
• Q p - average water supply by the pump filling the AC, or water flow from the fire column installed on the fire hydrant (l / s);
• N pr - the number of water supply devices to the place of fire extinguishing (pcs.);
• Q pr - total water consumption from the water supply devices from the AC (l / s).

Rice. 2. Scheme of water supply by the method of delivery by fire trucks.

Water supply must be uninterrupted. It should be borne in mind that at water sources it is necessary (mandatory) to create a point for refueling tankers with water.

Example. Determine the number of tankers АЦ-40(130)63b for the supply of water from a pond located 2 km from the fire site, if it is necessary to supply three stems B with a nozzle diameter of 13 mm for extinguishing. Tanker trucks are refueled by AC-40(130)63b, the average speed of tanker trucks is 30 km/h.

Solution:

1) We determine the time for the AC to travel to the place of fire or back.

t SL \u003d L 60 / V DVIZH \u003d 2 60 / 30 \u003d 4 min.

2) We determine the time for refueling tankers.

t ZAP \u003d V C / Q N 60 \u003d 2350 / 40 60 \u003d 1 min.

3) We determine the time of water consumption at the site of the fire.

t RASH \u003d V C / N ST Q ST 60 \u003d 2350 / 3 3.5 60 \u003d 4 min.

4) We determine the number of tankers for the supply of water to the fire site.

N AC \u003d [(2t SL + t ZAP) / t RASH ] + 1 \u003d [(2 4 + 1) / 4] + 1 \u003d 4 tank trucks.

Method for calculating the water supply to the place of fire extinguishing using hydraulic elevator systems

In the presence of swampy or densely overgrown banks, as well as at a significant distance to the water surface (more than 6.5-7 meters), exceeding the suction depth of the fire pump (high steep bank, wells, etc.), it is necessary to use a hydraulic elevator to take water G-600 and its modifications.

1) Determine the required amount of water V SIST required to start the hydraulic elevator system:

VSIST = NR VR K ,

NR= 1.2 (L + ZF) / 20 ,

• Where NR− number of hoses in the hydraulic elevator system (pcs.);
• VR− volume of one sleeve 20 m long (l);
• K− coefficient depending on the number of hydraulic elevators in a system powered by one fire engine ( K = 2- 1 G-600, K =1,5 - 2 G-600);
• L– distance from AC to water source (m);
• ZF- actual height of water rise (m).

Having determined the required amount of water to start the hydraulic elevator system, the result obtained is compared with the water supply in the fire truck, and the possibility of putting this system into operation is determined.

2) Let us determine the possibility of joint operation of the AC pump with the hydraulic elevator system.

And =QSIST/ QH ,

QSIST= NG (Q 1 + Q 2 ) ,

• Where AND– pump utilization factor;
• QSIST− water consumption by the hydroelevator system (l/s);
• QH− supply of the fire engine pump (l/s);
• NG− number of hydraulic elevators in the system (pcs.);
• Q 1 = 9,1 l/s − operating water consumption of one hydraulic elevator;
• Q 2 = 10 l/s - supply of one hydraulic elevator.

At AND< 1 the system will work when I \u003d 0.65-0.7 will be the most stable joint and pump.

It should be borne in mind that when water is taken from great depths (18-20m), it is necessary to create a head of 100 m on the pump. Under these conditions, the operating water flow in the systems will increase, and the pump flow will decrease against normal and it may turn out that the sum and the ejected flow rate will exceed the pump flow rate. Under these conditions, the system will not work.

3) Determine the conditional height of the rise of water Z USL for the case when the length of hose lines ø77 mm exceeds 30 m:

ZUSL= ZF+ NR· hR(m),

Where NR− number of sleeves (pcs.);

hR− additional pressure losses in one sleeve on the line section over 30 m:

hR= 7 m at Q= 10.5 l/s, hR= 4 m at Q= 7 l/s, hR= 2 m at Q= 3.5 l/s.

ZF – actual height from the water level to the axis of the pump or the neck of the tank (m).

4) Determine the pressure on the AC pump:

When water is taken by one G-600 hydraulic elevator and a certain number of water shafts are operated, the pressure on the pump (if the length of rubberized hoses with a diameter of 77 mm to the hydraulic elevator does not exceed 30 m) is determined by tab. 1.

Having determined the conditional height of the rise of water, we find the pressure on the pump in the same way according to tab. 1 .

5) Define the limit distance L ETC for the supply of fire extinguishing agents:

LETC= (HH- (NR± ZM± ZST) / SQ 2 ) · 20(m),

• Where HH− pressure on the fire truck pump, m;
• HR− head at the branch (taken equal to: HST+ 10), m;
• ZM − elevation (+) or descent (-) terrain, m;
• ZST− height of lifting (+) or lowering (−) trunks, m;
• S− resistance of one sleeve of the main line
• Q− total flow from shafts connected to one of the two most loaded main lines, l/s.

Table 1.

Determination of the pressure on the pump during the intake of water by the G-600 hydraulic elevator and the operation of the shafts according to the corresponding schemes for supplying water to extinguish the fire.

95 70 50 18 105 80 58 20 – 90 66 22 – 102 75 24 – – 85 26 – – 97

6) Determine the total number of sleeves in the selected scheme:

N R \u003d N R.SIST + N MRL,

• Where NR.SIST− number of hoses of the hydraulic elevator system, pcs;
• NSCRL− number of sleeves of the main hose line, pcs.

Examples of problem solving using hydraulic elevator systems

Example. To extinguish a fire, it is necessary to submit two trunks, respectively, to the first and second floors of a residential building. The distance from the fire site to the tanker ATs-40(130)63b installed on the water source is 240 m, the elevation of the terrain is 10 m. feeding it to the trunks to extinguish the fire.

Solution:

Rice. 3 Scheme of water intake using hydraulic elevator G-600

2) We determine the number of sleeves laid to the G-600 hydraulic elevator, taking into account the unevenness of the terrain.

N P \u003d 1.2 (L + Z F) / 20 \u003d 1.2 (50 + 10) / 20 \u003d 3.6 \u003d 4

We accept four sleeves from AC to G-600 and four sleeves from G-600 to AC.

3) Determine the amount of water needed to start the hydraulic elevator system.

V SIST \u003d N P V P K \u003d 8 90 2 \u003d 1440 l< V Ц = 2350 л

Therefore, there is enough water to start the hydroelevator system.

4) We determine the possibility of joint operation of the hydraulic elevator system and the tank truck pump.

And \u003d Q SIST / Q H \u003d N G (Q 1 + Q 2) / Q H \u003d 1 (9.1 + 10) / 40 \u003d 0.47< 1

The operation of the hydraulic elevator system and the tank truck pump will be stable.

5) We determine the required pressure on the pump for taking water from the reservoir using the G-600 hydraulic elevator.

Since the length of the sleeves to G−600 exceeds 30 m, we first determine the conditional height of the water rise: Z