Fire prevention Исполнитель

Fire prevention

Under fire prevention refers to training of fire safety and a set of measures aimed at preventing fires. Fire protection - it measures aimed at reducing the damage in case of fire. Between these two main objectives of fire safety is not always a clear boundary, such as in the case of actions aimed at limiting the scope of the spread of fire in fire. Since most of the time most people spend in buildings, focusing on fire safety of buildings. Specialized measures of fire prevention and protection of forests require fire safety, road transport, rail, air and sea transport, as well as underground tunnels and shafts.

The main elements of a fire. In order to start a fire, you must be in one place three elements: a flammable material, heat and oxygen. The combination of these three elements in the fire is uncontrollable chain reaction. Since combustion requires all three elements, removing one of them, you can prevent fire or to extinguish the fire. The type of combustible material depends on the class of fire, which defines the ways and means to extinguish. In some countries regulations fires are divided into four classes: A - conventional ignition of combustible materials such as wood, paper and plastic; B - ignition of flammable or combustible liquids, gases and lubricants; C - electrical fires; D - ignition of combustible metals. The degree of fire depends on the type and quantity of combustible material in this fire-danger zone.

Responsible authorities and their responsibilities. Fire prevention is traditionally limited to training and safety measures for the prevention of fires and always be the responsibility of the municipal Fire Department. Today the range of activities on fire prevention enlarged, and it included checking and approval of construction projects, monitor the implementation of regulations on fire safety, the fight against arson (including those with flammable games teens), data collection, as well as coaching and training a wide public and special troops. The problem of fire prevention can be divided into three broad, but closely related sets of activities: 1) training, including dissemination of knowledge on fire behavior (the need to install home smoke indicators and storing lighters and matches out of reach of children), 2) fire control, provides for the development of state of fire safety and building standards, as well as verification of their implementation, and 3) provision of equipment and technical development (installation of portable fire extinguishers and making safe use of lighters). Of the three complexes of the hardest events, seem to fire control. In the field of supervision included standards for fire prevention, building fire codes, standards, manufacturing and installation of fire equipment and fire safety standards for consumer goods.

Fire protection.Activities for fire protection include: 1) control of materials, products and equipment, 2) actively control the spread of fire with the use of fire alarm systems, automatic fire extinguishers and portable, and 3) a passive system, limiting the spread of fire, smoke, heat and gases by partitioning the premises, and 4) the evacuation of people from a burning building to safety.

Fire alarm system. In case of fire should immediately trigger fire alarm system, followed by a regulated system of measures. 

Special bond. The system provides a special communication of messages about the fire staff fire department. Message can reach to the public telephone network, from the alarm button provided outside the building, on the phone hands-free, from two-way portable radios, from the municipal fire alarm system or a commercial system of automatic signaling. All messages are automatically recorded, along with all the radio and voice messages from the fire department. Fire management must accept and process the signal, quickly send firefighters to the fire place and to begin operations in fire fighting.

Protective alarm system. Protective signaling system transmits a signal fire, the control signal and failure (in speech or digital form) from the place of installation of the alarm button on the other side of the building or on the remote control station, served by the usual division of the relevant specialization. 

Domestic indicators smoke and alarm systems. The most common single-and multi-point indicators smoke (each with its own power supply and signaling). Indicators of smoke come in three types: ionization, photoelectric, and combination (ionization-photoelectric). In the ionization indicator smoke a small amount of radioactive isotopes (americium-231), which ionizes the air in the sensor, making it electrically conductive. Smoke particles reduce the conductivity of air, and therefore the acoustic signal. In the chamber with a photo detector photoelectric smoke indicator provides a small source of light. In the presence of smoke in the chamber varies the amount of light falling on the photocell, causing a beep. Performance indicators for different types of smoke are about the same. All they can run on battery or AC power or on a network with a backup battery. Some regulations prescribed by such an electrical connection Multipositional indicators smoke, where they all give an audible alarm in case of triggering at least one indicator. Regardless of the principle of light smoke should give a signal to the audio signal level not lower than 85 decibels at a distance of 3 m. In order to properly working smoke detector lights, you must perform regular care procedures, maintenance and testing required by the manufacturer's instructions. Household fire alarm systems are usually a variety of indicators of smoke that are connected to a common control unit powered by AC and a separate battery pack that can feed the system for 24 h. Such systems are often also equipped with heat detectors, manual (button), alarms, bells and sirens. In the combined system provides both fire and burglar alarm systems and the signal of the second signal are canceled first.

Automatic fire alarm system. In non-residential buildings used automatic fire alarm system with smoke, heat, or flames of gas analyzers’ sensors. Heat sensors are inexpensive and reliable, but triggered later than indicators of smoke. Thermal sensors can operate in different modes. Some triggered upon reaching a certain temperature; others - after reaching a certain temperature rise rate of, say, 7-8 ° C / min. Air sensor  triggered when due to heating of air in the room increases the gas pressure in a sealed tube. Thermistor sensor generates a signal when, due to increasing the indoor temperature exceeds the value of electrical resistance. In gas analyzers’ sensor for the detection of combustion gases in the air serves as a semiconductor element or a catalyst. Alarm with such sensors is triggered when you change the conductivity of the semiconductor element or the temperature of the catalyst. Detectors of carbon monoxide (CO) with a semiconductor sensor element is not very suitable for fire safety systems (since CO is formed at a rather late stage of a fire), but they perform exceptionally well as sensors dangerous concentrations of CO, produced by faulty stoves and heaters. Technical specifications of various industries require mandatory installation of CO-detectors in the fire areas. Flame detectors that are used usually only in areas of high fire danger, react to the infrared or ultraviolet radiation of the flame.

Automatic fire extinguishing system. Apply liquid, carbon dioxide, powder and foam automatic fire extinguishing system. The most common water system - it's simply a system of water pipes, sprinkler heads, ending with thermo-sensitive valves. Under the influence of heat valve sprinkler head opens, and out spurts of water, is widely sprayed mechanical reflectors. Each head is individually activated in accordance with the temperature in the place of its location. (In other work of flood, this will be discussed below.) System to work properly, sprinkler heads should not be filled with paint, they should not hang any objects and the space around them should not be cluttered. In "wet" water fire suppression systems piping are always filled with water under pressure. In the "dry" systems, pipes filled with compressed air or nitrogen, until you reach the sprinkler head, after which the pressure in the tube decreases and the water begins to flow on the pressure side. In systems previewing the fire alarm valve opens and fills the tube with water before starting sprinkler head. Sometimes the principles of dry system and previewing match in one system. In the flood systems, sprinkler heads are always open, and fire alarm controls the overall water valve so that water flows in fire at once in all the sprinkler heads. Provision is also special water system to protect the exterior walls of buildings and for other special tasks. Automatic water fire extinguishing system of household registration destination end of the century require such small amounts of water that a sprinkler head is sufficient for an area of ​​almost 40 m². Distribution of splashing water is such that when operating the sprinkler heads protected furniture in the corners of the rooms and even the ceiling. 
Portable fire extinguishers. Portable fire extinguishers are divided into four classes to the classes of fire. Some of them are suitable for extinguishing fires two or three different classes, but not all four.

Fire barriers. Device fire barriers that prevent the fire from spreading from one part of the building to adjoining rooms, is a very important measure to ensure fire safety. Widespread fire entails an increase in human losses and material damage, but also dramatically impedes the fight against fire. Although the fire only 20% of home fires goes beyond the ground floor where a fire occurred at the 20% accounted for almost 70% of the dead, more than 30% of the victims and about 70% of property losses. Smoke and fumes can spread much farther than the flame, creating a danger for people who are far away from the zone of fire. Smoke and combustion gases from even a small fire can cause damage or disruption to the operation of computers and other sensitive electronic equipment. Fire barriers - a special fire walls (firewalls) and fire-proof floors, designed so that they prevented the spread of flame, smoke and heat horizontally (from the apartment in an apartment on the same floor) or vertical (from floor to floor) inside buildings, as well as from one building to another. Provision is also fire zones - areas of the building, made of fireproof materials and separating it into isolated sections. Such zones without fire and smoke can serve as a refuge for people caught up in a building fire. 

Constructions. Protecting and supporting structures of the building (the walls and ceiling) with the right approach are important elements of fire safety as keep the fire within one room, one section of one floor. In the fire and building codes establish the necessary limits of fire resistance of such structures. Fire resistance - this time in hours or minutes, during which the building construction resists the effects of fire or heat of fire. However, the specified standard values ​​refer to standard test conditions and can only serve for orientation, especially as unprotected openings for doors, windows, ventilation and cable routing reduces the ability of the enclosing structure to contain the spread of fire, smoke, heat and gases. 
Doors, windows and doors. Such devices are used to protect openings in fire walls. From them, too, requires an appropriate level of fire resistance, and they provide protection only in the closed position.

Separation of buildings. Radiant heat and sparks local fire threaten its transfer to neighboring buildings. Protection is provided by a normalized "fire" the distance between buildings. If the terms of the construction of such a distance cannot be sustained, it must be compensated by an increase in fire resistance enclosing structure.

Evacuation of people. In fires in buildings primarily has the task of protecting people through their evacuation to a safe area. In some cases, instead of the immediate evacuation of the method of "protection on the ground" - people are temporarily sheltered in the inner zone of fire. Such areas (hallways to elevators, stairwells extended), are protected by automatic fire suppression systems, separated from adjacent areas free intervals or smoke proof and fire-resistant building envelopes.

Evacuation system should give people the opportunity to enter a safe zone during the fire. It should provide a continuous does not overlap the path out of any place of the building to the street and provide special easy opening door locks, horizontal exits, intercommunication staircase smoke tight mines, fire escapes, escalators, passenger conveyors horizontal elevators, windows, emergency lighting and exit signs . Building owners and tenants are often cluttering the corridors, doors and stairwells stored various things that a fire could lead to tragic consequences.