RU2053822C1 - Aerosol fire fighting plant - Google Patents

Abstract

FIELD: fire fighting equipment. SUBSTANCE: power supply source of aerosol plant is manufactured in the form of sealed thermodynamic high-pressure vessel with fire suppression means located in protected room and connected to main pipe-line at point of arrangement of its liquid phase. Plant enable to prevent blasts and to suppress fires in baths-saunas. Design of plant in the form of sealed interconnected vessels-radiators joined to pipe-line with the aid of throttling pipes enhanced operational safety of plant. EFFECT: improved fire fighting capabilities of plant. 2 dwg

Description

 The invention relates to fire fighting equipment, in particular to automatic fire extinguishing installations, and is intended to prevent explosions and eliminate fires in heat chambers of Finnish baths (saunas) with stove, gas and electric heating, and can also be used to extinguish fires in drying chambers and drying cabinets with combustible materials.

It is known that thermal cameras are sauna baths dry steam, in which the temperature is maintained hovering mode from 110 to ¹⁴⁰ ° C at a humidity in the range of 5-6% (see. Vol. P.P.Evseev. How to build Russian and Finnish bath. M. Stroyizdat, 1981, p. 9).

From fire extinguishing practice it is known that fires in saunas occur mainly for the following reasons:
insufficient fire fighting between combustible building structures of saunas and heating devices.

The fires arising for this reason are usually detected by personnel in the initial stage of its development and are eliminated by primary fire fighting means before the arrival of fire departments;
a malfunction in the automatic temperature control system,
negligence of maintenance personnel or soaring people who forget to turn off the heating devices at the end of the washing process (with malfunctioning automation).

The unregulated process of heating the air in the sauna heat chamber leads to its overheating and decomposition (gas evolution) of the wood cladding of the walls, ceiling and shelves of the sauna. At a temperature of 200 to 400 ^{° C} is an intensive expansion timber and is allocated the bulk of the gaseous decomposition products: carbon monoxide of 25% hydrogen 30% methane 33% carbon dioxide 9% These gaseous products may explode (ignited) at their concentration in a volume space from 5 to 40% (see Prince P.G.Demidov and V.S. Saushev. Combustion and Properties of Combustible Substances, VIPTS of the Ministry of Internal Affairs of the USSR, Publishing Department, M. 1975, p. 226).

 During a fire in the sauna, due to the limited access of air to it, the concentration of combustible gases in the room reaches more than 80% and you just have to open the door to the sauna or break the window glass, as a fresh air stream dilutes the combustible gas to explosive (5-40% ) and an explosion occurs.

 A known installation of aerosol fire extinguishing with water, containing a container under the pressure of the extinguishing agent, a bubbler for the extinguishing agent, inlet and outlet nozzles with shutoff and safety valves.

 A distinctive feature of this installation is that in order to increase safety while reducing the metal consumption of its design, the tank is divided by transverse bulkheads into a series of compartments connected to the bubble chamber by throttling holes in their lower part, and adjacent compartments are interconnected by throttling holes in their upper part.

 This setting is described in A.S. N 1725929, cl. A 62 C 27/00, 1989, author V.P. Demin et al.

In said apparatus for fire extinguishing use superheated water having a temperature of 120-200 ^o C, whereby it is achieved a high fire extinguishing effect, which is complex. At the moment of expiration of superheated water from the opening of the fire barrel into the atmosphere, a sharp boiling of a jet of water occurs due to the accumulated heat content. In this case, the jet is crushed, and most of the water is dispersed with a droplet size of not more than 10 microns, that is, it turns into an aerosol. A slight amount of vapor generated corresponding to the accumulated heat content (approximately 120-180 kcal, as is required for complete vaporization of at least 539 kcal.) In the dispersion is condensed and flowing out vapor-liquid stream at a distance of 20 cm from the shower already has all the temperature 40-50 ^{° C,} when the water temperature inside the tank is 120-200 ^o C.

 Drops of water with a size of 10 μm (aerosol) and condensed steam, falling into the zone of high temperature of the fire, boil instantly, taking heat from the burning substance as much as possible, while the generated vapor (1700 volumes) fills the room, displacing air oxygen.

 The disadvantages of this installation include the fact that in order to constantly maintain the temperature of the water inside the tank, its body must be insulated with heat-insulating material and a power source (steam or electric heating elements) must be supplied to heat the water inside the tank.

 Stationary automatic installations for extinguishing fires by steam are known, containing a fire extinguishing agent power source (steam boiler or steam line), perforated main and distribution pipelines, stop and start valves, control, control and fire alarm devices.

A distinctive feature of this installation is that water is used to eliminate the fire, released to the fire through the holes of the perforated distribution pipes. These fire extinguishing installations provide a 35% by volume fire extinguishing concentration of water vapor for 3-5 minutes of operation of the installation, with a steam supply rate of 0.002-0.005 kg / (m ³ · s). These settings are described in the book by A.N. Baratov, E.N. Ivanov. Fire extinguishing at the enterprises of the chemical, petrochemical and oil refining industries. M. Chemistry, 1971, p. 313, fig. 138).

These fire extinguishing installations have the following disadvantages:
1. The need to have a boiler plant or process main steam line.

 2. The increased metal consumption of the steam extinguishing installations in relation to the aerosol water fire extinguishing installations with superheated water, since when a stream of superheated water flows through an opening equal to the steam outlet, the amount of steam from the superheated water will be more than 40 times the steam consumption, which, respectively , 40 times increases the effectiveness of aerosol fire extinguishing (see A.N. Baratov and E.N. Ivanov. Fire extinguishing at the enterprises of the chemical, petrochemical and oil refining industries, M. Chemistry, 1971, p.209, 319).

3. Increased risk of plant operation, since it is triggered to the protective room via the perforated pipes supplied steam with a temperature of ^about 120-200 C (in spray installations superheated water at a distance of 20 cm from the shower vapor-liquid stream has a temperature of 40-50 ° ^C).

 The aim of this invention is the prevention of explosions and the elimination of fire in the volume of the protected premises (saunas), as well as reducing the cost of the fire extinguishing installation and improving safety during its operation.

 This goal is achieved by the fact that in an aerosol fire extinguishing installation containing a fire extinguishing agent power supply that provides the flow and pressure necessary for fire extinguishing, perforated pipelines and distribution lines, shut-off and start-up valves, control devices, electrical interlock and fire alarm devices, fire extinguishing agent power supply made in the form of a sealed thermodynamic tank of high pressure, placed in a protected room and filled with a fire extinguisher. In this case, the thermodynamic capacity is connected to the main pipeline at the location of the liquid phase of the extinguishing agent.

 For the purpose of manufacturability and safe operation of the thermodynamic tank, it is made in the form of sealed thermodynamic vessels-high pressure radiators, interconnected with the main pipeline by throttling tubes with limited sections of passage openings, each of which is inversely proportional to the flow rate of the extinguishing agent and the number of thermodynamic vessels.

 In FIG. 1 shows a schematic diagram of an aerosol fire extinguishing installation mounted in a heat chamber (dry steam room) of a sauna with an electric heating device for heating the sauna; figure 2 automatic start valve installation with a hot-melt element.

 The aerosol extinguishing installation contains thermodynamic vessels-radiators 1 filled with fire extinguishing agent 2, main 3 and perforated distribution pipes 4, an automatic start valve 5 with a hot-melt element 6, a manual start valve 7, a pressure gauge 8, a pressure sensor 9 with an electrical contact device. Thermodynamic vessels-radiators 1 are connected to the main pipeline 3 by throttling tubes 10 with limited sections of passage openings. In the upper part, one of the thermodynamic vessels-radiators 1 is equipped with a fill level limiter 11 of a fire extinguishing agent with a sealing plug and a zinc piece 12 placed inside the sauna. An electric furnace 13 is installed in the sauna room for heating the air, and an automatic gas and air overpressure relief valve 14 is installed in the ceiling of the sauna mixture to the atmosphere.

 Aerosol extinguishing system operates as follows.

 Before putting the unit into operation, it is necessary to carry out its hydraulic tests in accordance with the Rules for the Design and Safe Operation of Pressure Vessels, approved by the USSR State Technical Supervision Service 27.11. 87 g

 To bring the steam extinguishing installation into working condition, the thermodynamic vessels-radiators 1 must first be filled with desalted or distilled water no more than 90% of the volume, and in one of the vessels-radiators a piece of zinc 12 should be attached to its upper sealing cover. Zinc, reacting with oxygen, absorbs it from water, which reduces the corrosion of the joints and walls of the fire extinguishing installation and prevents its destruction (see the journal Inventor and rationalizer, N 7, 1987, p. 46).

 The level of filling with water at 90% of thermodynamic vessels-radiators 1 is provided by a level 11 filling limiter integrated in one of the vessels of the nozzles, which is closed by a sealed plug.

An automatic beam valve 5 is installed on the main pipeline 3, for example, made of a typical non-return valve (Fig. 2), with shut-off elements attached to it in the form of a two-shouldered lever, a stop screw and a standard fusible element 6 from an OPS type foam sprinkler sprinkler to a standard operating temperature 182 ± 3 ^о С.

 For the aesthetic appearance of the sauna room and the exclusion of the contact of soaring people with the elements of the fire extinguishing installation (to prevent burns), they are closed (sheathed) with perforated boards in the lower and upper parts for air movement inside the casing and heat exchange between the thermodynamic vessels-radiators, and the perforated distribution pipe 4 is placed in a hollow ceiling.

During the heating of the air in the sauna room, for example, by an electric furnace 13, the air flows will also wash the surface of the walls of the thermodynamic vessels-radiators 1 and heat the extinguishing agent 2 inside them. Depending on the air temperature and water heating, a certain pressure will be created inside the radiator vessels : at ⁰ ° C 0.00623 kg / cm ^2, 50 ^{° C} 0.126 kg / cm ^2, 59.7 ^{° C} 0.2 kg / cm ^2, 80.9 ^{° C} 0.5 kg / cm ^2, 99, 1 ^о С 1 kg / cm ² , 100 ^о С 1,033 kg / cm ² , 150 ^о С 4,854 kg / cm ² , 179 ^о С 10 kg / cm ² - 182 ^о С 12 kg / cm ² , 200 ^о С 15,857 kg / cm ² (see. Handbook of elementary physics, N.I. Koshkin, M.G. Shirkevich, M. Nauka, 1966, p. 76).

When heated air in the heat chamber sauna to 100-140 ^C. automatic temperature control system turns off the electric furnace temperature 13. The heated up to this temperature the extinguishing means 2 in thermodynamic vessels radiator 1 will be cooled, and they both heat accumulators will deliver the accumulated heat in the sauna environment, the the most stabilizing its thermal regime. In the case in sauna air temperature drops below ⁰ ° C, the extinguishing means 2 within the receptacles thermodynamic radiators frozen, turn into ice, and the volume of extinguishing agent to increase by 1/11 volume and around 9% Because sosudy- radiators 1 are filled to 90% of their volume with a fire extinguishing agent 2, water, expanding and freezing, will fill the free space of the vessel-radiators 1 with ice and prevent the destruction (depressurization) of their walls.

If the temperature in the heat chamber sauna will rise above 140 ^{° C} due to a malfunction of the automatic temperature control or ensuing fire, when the temperature reached 182 ^{° C} destroyed hotmelt element 6 of the automatic valve 5, its closure member is opened and the extinguishing means 2 is under pressure of 12 atm flow into distribution pipelines and flow out of openings with a diameter of about 3 mm into the inter-ceiling space and under the skin of the sauna walls in the form of an aerosol, with its subsequent transformation into steam.

 Simultaneously with the start of the steam extinguishing installation (after 2-3 s), an automatic valve 14 for relieving the excess pressure of the gas-vapor mixture from the sauna room to the atmosphere is activated. The overpressure relief valve 14 may, for example, be made of an asbestos-cement pipe passing through the ceiling of a sauna. The lower section of the pipe is closed by a spring-loaded plug and the pipe cavity is filled with bulk material (dry river sand). The spring from the other end has a perforated support circle resting in a spring state on a column of loose sand and prevents the plug from moving. When a jet of water flows out of the hole of the perforated pipe 4 passing through the lower end of the relief valve 14, the sand located in the asbestos cement pipe becomes fluidized, the sand particles lose their resistance and become fluid and flow out of the pipe into the sauna room. The valve plug 14 opens and excess steam pressure will be released to the atmosphere.

 Instead of valve 14, a pressure door for the sauna can be used for relieving pressure for this purpose if it is equipped with self-closing devices. In this case, the excess steam pressure will be discharged through the doorway and through the ventilation channels of adjacent rooms to the atmosphere. At the moment the steam extinguishing installation is triggered, the pressure in the perforated distribution pipe 4 rises to 12 atm, as a result of which the pressure sensor 9 is activated with an electrical contact device that disables the electrical lock of the electric furnace 13 and turns on the fire alarm device (not shown).

 The extinguishing system can be started manually by opening the manual start valve 7.

 Monitoring the water pressure inside the extinguishing system is carried out according to the control manometer 8, the scale of which should also be calibrated in degrees Celsius to determine the temperature inside the sauna.

 The implementation of the power source of the extinguishing agent of the aerosol extinguishing installation in the form of a sealed thermodynamic tank of high pressure with an extinguishing agent located in a protected room and connected to the main pipeline at the location of its liquid phase prevents explosions and eliminates fires in heat chambers of Finnish saunas.

 The implementation of the thermodynamic capacity in the form of sealed thermodynamic vessels-radiators of high pressure, interconnected and with the main pipeline in the liquid phase of the fire extinguishing agent, allows to reduce the cost of the fire extinguishing installation and increase the safety precautions during its operation.

 Making connections of the main pipeline with sealed thermodynamic vessels-radiators by means of throttling tubes with limited sections of the through holes, increases the safety precautions during operation of the aerosol extinguishing installation.

 The savings from using the aerosol fire extinguishing installation are obtained due to its reliable and safe operation and the prevention of explosions and fires in Finnish saunas, which exclude human casualties and injuries to firefighters during their fires.

Claims (3)

 1. AEROSOL EXTINGUISHING INSTALLATION, containing a power source for the fire extinguishing agent, providing the flow and pressure necessary for fire extinguishing, perforated pipelines and pipelines, shutoff and starting fittings, control devices, an electric blocking device and fire alarm system, characterized in that the fire extinguishing agent has a power source in the form of a sealed thermodynamic tank of high pressure, placed in a protected room and filled with a fire extinguishing agent, at m thermodynamic capacitance connected to the main pipe at the location of the liquid phase fire suppression agent.  2. Installation according to claim 1, characterized in that the thermodynamic tank is made in the form of sealed thermodynamic vessels-radiators of high pressure, connected to each other and to the main pipeline in the liquid phase of the fire extinguishing composition.  3. Installation according to claim 1, characterized in that the sealed thermodynamic vessels-radiators are connected to the main pipeline by throttling tubes, with cross-sections of through holes, the size of each of which is inversely proportional to the flow rate of the extinguishing agent and the number of thermodynamic vessels.

Images