Extinguishing a source of fire with finely divided water is the most popular method in situations of fire spread. When a class A fire ignites, as a rule, solid materials are ignited - wood, plastic, textile, rubber. Class B fire is an uncontrolled burning of liquid components that do not dissolve in liquids (paraffins, gasoline and petroleum products), as well as those that cannot be fully mixed (acetone, alcohols and glycerin).
Fire protection
Of course, all situations related to fire fighting include the use of water. Despite the popularity of the source and its frequency of use, it is important to remember the main disadvantages, because of which the effectiveness of fire extinguishing agents is greatly reduced.
The strength of the water directed at the source of fire can lead to the following consequences:
- in some cases, spoil valuables in the vicinity, as well as flood objects;
- inflict additional damage on nearby premises on which the source of ignition does not extend (for example, flooding of neighbors);
- with this method of extinguishing a fire, it is necessary to use additional water storage reserves with the presence of fire tanks and stations with pumping equipment.
All the described disadvantages do not arise when using quenching techniques with finely divided water. The use of this method is based on the creation of a special cloud of fine water droplets that are blown through special equipment with high pressure (over 250 bar).
This quenching method is also called surface. But it is important to know that in practice the sprayed reagent covers a much larger combustion area. In this case, the active formation of steam begins, which helps to prevent the penetration of oxygen to the source of ignition. As a result, the temperature is significantly reduced and the burning rate is minimized. To prevent re-ignition, fine mist should be maintained for 15 minutes.
Due to its natural properties, a liquid in a short time dissolves half of the substances. Such a fog absorbs all solid smoke particles, which helps to protect the room from fast and too much smoke.
When extinguishing a Class A fire, liquids are used that include exclusively water. In more dangerous situations, it is allowed to use extinguishing agents from foaming components. To do this, simply switch the valve mode to a position that promotes the formation of foam, after which the installation begins to function in the required mode.
How do fire extinguishing agents work?
There is no identical design to extinguish a fire, but the principle of operation of such devices is to spray liquid in the form of fog.
Simpler systems using finely atomized water are devices consisting of separate nodal installations, as well as a fire fighting agent.
The reservoir with the liquid is combined with a high-pressure sleeve with a separate gas cylinder in which the supporting-starting mechanism is installed. The area on which a fire may occur should be equipped with special irrigators. When the ignition sensor is triggered, a system is activated on the cylinder, which opens the penetration of the propellant along the sleeve directly into the fire department. The formed gas-liquid mixture passes through the pipeline to the sprinklers themselves.
Devices for extinguishing a fire with finely divided water can be of several types:
- With high pressure. In such equipment cylinders with nitrogen or high pressure pumps are installed. The desired consistency of the mixture is achieved mechanically.
- With low pressure. The device has a special tank in which the starting amount of gas is stored. Extinguishing components are also added to the gas-liquid mixture formed.
How to avoid problems with the operation of the device?
Fire brigade selects a list of frequently repeated errors when installing a finely dispersed liquid spray gun when extinguishing a fire. To prevent problems with the system and avoid violations, it is important to follow these rules:
- install a special cylinder with a small amount of gas - this is important to protect the selected area from fire;
- use equipment with a solution at a great distance from the sprinklers, and gas cylinders as close as possible to the tanks;
- divide the site into separate sections of fire protection;
- Do not install water tanks at too low a height as this will not produce the desired effect.
Autonomous fire extinguishing installations should be used in one room or in several small rooms at once.
It is important to divide buildings with an area of more than 1,000 square meters into plots, rationally placing equipment and storage tanks for propellant in them.
The main disadvantages of the system
Since most of the time the device for extinguishing a fire of finely dispersed liquid is in standby mode, there is a risk of slagging of the working holes in the nebulizers. In this case, the equipment can no longer fully protect the room, its performance is significantly impaired. To prevent such a situation, it is necessary to provide specialized closing valves in the device that will prevent holes in the nozzles from slagging.
Also, the main disadvantage of using a fire extinguishing installation with finely divided water is the need to equip the device with a specialized water treatment system.
Advantages and Drop Size
The positive qualities of the use of such equipment include eco-components of fire fighting. A simple method involves a total diameter of a drop of water up to 2 millimeters. With this mode of use, the fluid flow reaches 30%. Another part of the water is not used to extinguish the fire and is considered superfluous. It, as a rule, causes serious harm to valuable things in the area of ignition.
The extinguishing efficiency of a fire is greatly increased by reducing the droplet size to 150 microns. The small droplet size helps to significantly increase the cooling capacity, increases the penetration and extinguishing area at a water flow rate of up to one and a half liters per square meter.
The need for a large supply of fluid is greatly reduced, which helps prevent damage to salvaged things and valuables. This feature is very important for libraries, museums, various archives and other cultural buildings.
In addition to these facilities, fire extinguishing systems should be used in multi-level closed-type car parks, as well as in shopping and entertainment centers, training halls, sports complexes, cinemas, hotels, art exhibitions and other areas with high daily traffic.
The efficiency of the use of modular type devices is not affected by the number of ignition sources and their location in the area where the fire spreads. Such equipment is quite simple to install, and its operation does not depend on external sources of electricity. Another advantage of the fire extinguishing system is the non-toxicity of the reagents used.
Fires in high-rise buildings
High-rise buildings, due to their special characteristics, have a high degree of fire hazard, compared with the architecture of the optimal number of storeys.
In buildings with a large number of floors, a fire center spreads very quickly in the vertical direction. It is characterized by a strong smoke of escape routes, elevator shafts, stairways, upper floors. The fire that started in a high-rise building often entails the death of a large number of people. This is due to the complexity of installing security systems, evacuation and rescue operations.
In a fire, elevator equipment and systems that protect the building simply stop functioning normally.
On the upper floors of buildings, the most problematic are reconnaissance, rescue of people and the transfer of firefighting equipment.
When designing high-rise buildings, architects understand the whole risk and a number of problems that follow. In practice, this translates into economically disadvantageous and irrational spending. When extinguishing a fire in a public building, specialists most often face the following problems:
- the consumption of a large amount of liquid in the internal compartment, which cannot be provided by the urban network;
- the destruction of a huge amount of material assets during the activation of the fire system;
- flooding of electrical systems and disruption of the facility’s life support system.
A good alternative to the classic sprinkler AUPT is the TRV module.
How is the fire extinguishing module?
To extinguish a fire, only 1-1.5 liters of water per square meter is enough, which is fully consistent with the fire extinguishing module with finely sprayed water. Such a device works according to the following principle:
- The design is combined with special sensors, which, when a source of ignition is detected, activate an alarm - a trigger mechanism.
- ZPU works and opens a cylinder with displacing gas. The gas passes into the container with fire extinguishing components and forms the required pressure, and is mixed together with fire extinguishing additives and water, resulting in a gas-liquid mixture.
- Fire extinguishing devices with finely divided water include special pipelines with sprinklers. Under pressure, the gas-liquid composition enters the pipes and is thrown out in the form of a finely sprayed jet with small droplets.
- A special pressure sensor is installed on the main pipeline through which water is sprayed around the room, which monitors the supply of the right amount of water over a long distance.
- If an autonomous module is used, the formation and supply of finely dispersed liquid, and the system is turned on and off using the station itself. The composition already includes a special sensor to identify the source of ignition, as well as all the necessary devices for mixing and supplying the mixture.
The main advantages of the operation of such a device include:
- High rate of fire extinguishing at the enterprise and the use of a minimum amount of water.
- Safety of use. Spraying the composition to extinguish the fire can be carried out without waiting for the evacuation of people and personnel from the burning building. It is on this factor that the speed of the fight against fire depends in many respects.
- Such a module can be placed in buildings that are in the high-risk category. It has a protective case and thick-walled cylinders for storing displaced gas and fire fighting substances.
- Increased smoke deposition ability.
- The equipment works completely autonomously and depends only on the source of electricity and water supply.
- Installation is quite simple and does not require a lot of time and effort; you can connect yourself.
Device Usage Locations
Extinguishing a building fire with fine spray jets improves the functioning of the modules. Small droplets help to use fire extinguishing systems for electrical devices without the threat of electric shock. Also, such modules are well suited for combating fires of categories A, B and C.
Most often, modules with finely atomized water are used in rooms of the following type:
- industrial buildings;
- museums, libraries, art galleries and other buildings in which valuables and works of art are stored;
- archives, hotels, offices;
- warehouses;
- boiler rooms;
- shopping centers and other crowded places.
The choice of device will depend on the technical features of a particular room and established standards. If it is impossible to lay a pipeline to install a fire extinguishing module, fully autonomous device models are built into the building. In warehouse-type rooms with high ceilings, a centralized extinguishing system is most often installed.
Modules from trusted manufacturers
Extinguishing finely dispersed water with Typhoon is an effective method of neutralizing a fire in a short period of time. It uses atomized water with dissolved additives or extinguishing gases. With the help of them, the protection of the building is significantly increased and the safety of workers and visitors is ensured
The fire extinguishing system from Minifog EconAqua has an automatic system that helps create a gas-liquid mixture fed to the combustion site. Such a device helps in a short time to eliminate the source of ignition, even if it has already spread to a large area.
The “Hurricane” fine-sprayed water fire extinguishing module uses water in the form of small drops. The device has a simple structure, minimal maintenance costs and the optimal volume of liquid used to extinguish a fire. There are also variations on the device that use the powder fire fighting technique. In their effectiveness, they are not inferior to the technology of other manufacturers.
EL-MIST is an extinguishing module that eliminates fire through water mist resulting from the supply of fluid through special high-pressure sprayers. With the help of a finely dispersed structure, the liquid rapidly passes to a large area of the room, which leads to subsidence of the fog and the extinguishing of the fire.
The “TRV” module of finely atomized water is another device that can be used as actuating units in autonomous fire extinguishing systems at various production facilities.
What should the device provide?
In order to quickly and without loss cope with a fire, it is important to use special substances that will help to neutralize the spread of the flame, stopping its burning. The main tasks of fire extinguishing components are:
- exclusion of access to the fire;
- prevention of gas and fuel;
- a decrease in the activity of chemical reactions that help maintain combustion;
- cooling the combustion site to a temperature at which self-ignition cannot occur;
- dilution of a gaseous or liquid medium with substances incapable of burning.
The correct calculation and selection of the fire extinguishing module, the placement of irrigators in the room helps prevent dangerous consequences in case of sudden fire. With the help of efficient devices, ignition can be eliminated in a short period of time. This will help preserve all the valuables that are in the building, as well as prevent accidents at the facility.