The intensity of the supply of fire extinguishing agents.

In practical calculations, the amount of fire extinguishing agents required to stop burning is determined by the intensity of their supply. The intensity of the supply is the amount of fire extinguishing agent supplied per unit of time per unit of the corresponding geometric parameter of the fire (area, volume, perimeter or front). The intensity of the supply of fire extinguishing agents is determined empirically and by calculations in the analysis of extinguished fires:

I u003d Q o.s / 60t t P, (2.2)

where I is the intensity of the supply of fire extinguishing agents, l / (m 2 s), kg / (m 2 s), kg / (m 3 s), m 3 / (m 3 s), l / (m ·with);

Q o.s – consumption of fire extinguishing agent during extinguishing a fire or conducting an experiment, l, kg, m 3 ;

t t – time spent on extinguishing a fire or conducting an experiment, min;

P – the value of the design parameter of the fire: area, m 2 ; volume, m 3 ; perimeter or front, m.

The feed intensity can be determined through the actual specific consumption of the fire extinguishing agent;

I u003d Q y / 60t t P, (2. 3)

where Q y is the actual specific consumption of the fire extinguishing agent during the time of the cessation of combustion, l, kg, m 3 .

For buildings and premises, the intensity of supply is determined by the tactical costs of fire extinguishing agents on fires that have taken place:

I = Q f / P, (2.4)

where Q f is the actual consumption of the fire extinguishing agent, l / s, kg / s, m 3 / s (see clause 2.4).

Depending on the calculation unit of the fire parameter (m 2 , m 3 , m), the intensity of the supply of fire extinguishing agents is divided into surface [I s , l / (m 2 s), kg / (m 2 s)], volumetric [I v , l / (m 3 s), kg / (m 3 s)] and linear [I l , l / (m s), kg / (m s)] /

If the regulatory documents and reference literature do not contain data on the intensity of the supply of fire extinguishing agents to protect objects (for example, in case of fires in buildings), it is set according to the tactical conditions of the situation and the implementation of combat operations to extinguish the fire, based on the operational and tactical characteristics of the object, or take reduced by 4 times compared with the required intensity of supply for extinguishing a fire

I c u003d 0.25 I tr , (2.5)

The linear intensity of the supply of fire extinguishing agents for extinguishing fires in the tables, as a rule, is not given. It depends on the situation on the fire and, if used in the calculation of fire extinguishing agents, it is found as a derivative of the intensity of the surface:

I l u003d I s h t , (2.6)

where h t is the depth of extinguishing, m (accepted, when extinguishing with hand trunks -5 m, fire monitors – 10 m).

The total intensity of the supply of fire extinguishing agents consists of two parts: the intensity of the fire extinguishing agent involved directly in the cessation of combustion I pr.g , and the intensity of losses I sweat.

I u003d I pr.g + I sweat. , (2.7)

The average, practically expedient, values of the intensity of the supply of fire extinguishing agents, called optimal (required, calculated), established empirically and in the practice of extinguishing fires, are given below and in Table. 2.5 – 2.10.

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

Buildings and constructions

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
Hangars, garages, workshops, tram and trolleybus depots 0.20
Hospitals 0.10
Residential buildings and outbuildings:
I – III degree of fire resistance 0.03
IV degree of fire resistance 0.10
V degree of fire resistance 0.15
basements 0.15
attic space 0.15
Animal buildings
I – III degree of fire resistance 0.10
IV degree of fire resistance 0.15
V degree of fire resistance 0.20
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
Industrial buildings
sections and workshops with the category of production in buildings:
I – II degree of fire resistance 0.35
III degree of fire resistance 0.20
IV – V degree of fire resistance 0.25
paint shops 0.20
basements 0.30
combustible coatings of large areas in industrial buildings:
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 of inventory items 0.20
Refrigerators 0.10
Power plants and substations:
cable tunnels and mezzanines (water mist supply) 0.20
Machine rooms and boiler rooms 0.20
Fuel galleries 0.10
transformers, reactors, oil circuit breakers (water mist supply) 0.10
2.Vehicles
Cars, trams, trolleybuses in open parking lots 0.10
Planes and helicopters:
interior finish (for mist water supply) 0.08
constructions with the presence of magnesium alloys 0.25
Frame 0.15
Vessels (dry cargo and passenger):
superstructures (internal and external fires) when supplying solid and finely sprayed jets 0.20
Holds 0.20
3. Hard materials
paper loosened 0.30
Wood:
balance, with humidity, %
40 – 50 0.20
less than 40 0.50
lumber in stacks within the same group at humidity,%;
6–14 0.45
20 – 30 0.30
over 30 0.20
round wood in stacks 0.3
wood chips in piles with a moisture content of 30 – 50% 0.10
Rubber (natural or artificial), rubber and rubber products 0.30
Flax fire in dumps (supply of mist water) 0.20
Flax straws (stacks, bales) 0.25
Plastics:
Thermoplastics 0.14
Thermoplastics 0.10
Polymeric materials and products from them 0.20
textolite, carbolite, plastic waste, triacetate film 0.30
Peat on milling fields with a moisture content of 15 – 30% (at a specific water consumption of 110 – 140 l / m 2 and an extinguishing time of 20 minutes) 0.10
Milling peat in stacks (at a specific water consumption of 235 l/m and extinguishing time of 20 min) 0.20
Cotton and other fibrous materials:
open warehouses 0.20
Closed warehouses 0.30
Celluloid and products made from it 0.40
Pesticides and fertilizers
4. Flammable and combustible liquids (when extinguishing with water mist)
Acetone 0.40
Oil products in containers:
With a flash point below 28 ° C 0.30
Flash point 28 – 60 o C 0.20
With a flash point over 60 °C 0.20
Flammable liquid spilled on the surface of the site, in the trenches of technological trays 0.20
Thermal insulation impregnated with petroleum products 0.20
Alcohols (ethyl, methyl, propyl, butyl, etc.) in warehouses and distilleries 0.40
Oil and condensate around the fountain well 0.20

Notes: 1. When water is supplied with a wetting agent, the intensity of supply according to the table is reduced by 2 times.

2. Cotton, other fibrous materials and peat must be extinguished only with the addition of a wetting agent.

TABLE 2.5. INTENSITY OF SUPPLY OF 6% SOLUTION IN FIRE EXTINGUISHING WITH AIR-MECHANICAL FOAM ON THE BASIS OF PO-1 FOAM

Buildings, structures, substances and materials Solution supply rate, l / (m 2 s)
medium expansion foam low expansion foam
1. Buildings and structures
Objects for processing hydrocarbon gases, oil and oil products:
Apparatuses of open technological installations 0.10 0.25
Pumping stations 0.10 0.25
Spilled oil product from the apparatus of the process unit, indoors, in process trays 0.10 0.25
Container storage of combustibles and lubricants 0.08 0.25
Synthetic rubber polymerization shops 1.00
Power stations and substations:
Boiler rooms and • engine rooms 0.05 0.10
Transformers and oil circuit breakers 0.20 0.15
2. Vehicles
Planes and helicopters:
Flammable liquid on concrete 0.08 0.15
Flammable liquid on the ground 0.25 0.15
Oil tankers:
Petroleum products of the first category (flash point below 28 ° C) 0.15
Petroleum products of the second and third category (flash point 28 ° C and above) 0.10
Dry cargo, passenger and oil tankers:
Holds and superstructures (internal fires) 0.13
Engine and boiler department 0.10
3. Materials and substances
Rubber, rubber, rubber products 0.20
Oil products in tanks:
Gasoline, naphtha, tractor kerosene and others with a flash point below 28 ° C 0.08 0.12*
lighting kerosene and others with a flash point of 28 ° C and above 0.05 0.16
Fuel oils and oils 0.05 0.10
Oil in tanks 0.05 0.12*
Oil and condensate around the fountain well 0.05 0.15
Spilled flammable liquid on the territory, in trenches and technological trays (at normal temperature of the flowing liquid) 0.05 0.15
Expanded polystyrene (PS-1) 0.08 0.12
hard materials 0.10 0.15
Thermal insulation impregnated with oil products 0.05 0.10
Cyclohexane 0.12 0.15
Ethyl alcohol in tanks, previously diluted with water up to 70% (supply of 10% solution based on PO-1C) 0.35

Notes: 1. An asterisk indicates that extinguishing with low expansion foam of oil and oil products with a flash point below 28 °C is allowed in tanks up to 1000 m 3 , excluding low levels (more than 2 m from the upper edge of the tank side).

2. When extinguishing oil products using the PO-1D foaming agent, the intensity of the foaming solution supply increases by 1.5 times.

TABLE 2.6. INTENSITY OF SUPPLY OF MEANS FOR EXTINGUISHING A JET TORCH IN OPEN TECHNOLOGICAL INSTALLATIONS

Type of jet torch Jet supply intensity, kg/kg
gas-water powder compact water
Compact jet:
combustible gas and liquid 7.0 4.0 21.0
liquefied gas 15.0 3.8
spray jet
combustible gas and liquid 15.0 3.8
liquefied gas 15.0 3.8
Natural gas (fountain) 6.0 3.0

The intensity of the supply of fire extinguishing powder compositions (OPS) when extinguishing some fires kg / (m 2 s)

Organoaluminum organolithium compounds (AOC, VOC) (bottled) 0.50
Wood 0.08
Petroleum products with a flash point of vapors of 28 ° C and below (spill)
When extinguishing fire monitors 1.00
When extinguishing with a hand barrel 0.35
Petroleum products with a vapor flash point above 28 ° C (spill) 0.16
Aircraft 0.30
Liquefied gas (spill):
When extinguishing fire monitors 1.00
When extinguishing with a hand barrel 0.35
Alcohol 0.30
Toluene 0.20

TABLE 2.7. FIRE EXTINGUISHING CONCENTRATIONS OF SOME HALOHYDROCARBONS, COMPOSITIONS BASED ON THEM AND OTHER SUBSTANCES

Symbol Components, % Estimated concentration
% about. kg / m 3
3.5 Ethyl bromide – 70 Carbon dioxide – 30 6.7 0.290
– 4ND Ethyl bromide – 100 Ethyl bromide -97 Carbon dioxide – 3 5.4 5.6 0.242 0.203
Methylene bromide – 80 Ethyl bromide – 20 3.0 0.157
BF-1 Ethyl bromide – 84 Tetrafluorobromoethane – 16 4.8 0.198
BF-2 Ethyl bromide – 73 Tetrafluorobromoethane – 27 4.6 0.192
bm Ethyl bromide -70 Methylene bromide – 30 4.6 0.184
Freon 114V2 Tetrafluorodibromoethav – 100 3.0 0.250
Freon 13V1 – – Trifluorobromomethane – 100 Carbon dioxide – 100 Steam – 100 4.0 0.260 0.70 0.30

TABLE 2.8. INTENSITY OF SUPPLY OF GAS EXTINGUISHING MEANS (FOR ROOMS UP TO 500 m2 )

extinguishing agent Feed rate, kg / (m 3 s), in rooms with openings
closed open
water vapor 0.002 0.005
Composition: 3.5 BF-1 4ND Carbon dioxide 0.003 0.002 0.002 0.001 0.006 0.006 0.005 0.005 0.004 0.015

TABLE 2.9. INTENSITY OF SUPPLY OF SPRAYED WATER TO LOCALIZE THE BURNING OF A JET TORCH DURING FIRES IN OPEN TECHNOLOGICAL INSTALLATIONS FOR THE PROCESSING OF COMBUSTIBLE LIQUIDS AND GASES

barrel type Intensity of sprayed water supply l/kg, at a distance to the protected equipment, m
Hand barrels: RS-A, RS-B, RSK-50 Turbine sprayers: NRT-5, NRT-10, NRT-20 7.0 3.5 5.0 2.5 3.5 2.0 3.0 1.5 2.5 1.0
For torch irrigation to reduce heat flow when creating a safe zone in the process of combat work
Atomized jets: from hand barrels from turbine atomizers 20.0 10.0 15.0 7.0 10.0 5.0 8.0 4.0 7.0 3.0



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