What is a smoke alarm system?
In practice, there are a lot of factors influencing the efficiency of smoke removal. These are:
- chemical reactions of burning materials with atmospheric oxygen;
- turbulent mixing of various temperature air flows;
- diffusion and heat transfer.
Such ventilation is only created where there is no natural ventilation. This is a system that can be turned on from a remote control panel outside the ventilated room. Anti-smoke protection of buildings and structures is regulated by SNIP, all materials and structures must be fire-resistant, channels and corridors are calculated using special formulas.
This protection performs the following tasks:
- limits the spread of volatile combustion products;
- removes smoke and gases;
- isolates the place of ignition.
In large industrial or residential buildings, a smoke detector is installed for each specific zone, this is a channel or shaft with a valve installed in them. The channel or mine ends with a reservoir for air drawn out from the room, this is an area of no more than 1600 m2, enclosed by non-flammable curtains.
During the construction and operation of the building, the system is in an inoperative state, according to the regulations it must be checked regularly. In the event of a fire, the valve automatically opens, smoke leaves the room, and people have time to save.
Types of smoke protection
Smoke protection systems come with a natural and artificial motivation. In naturally-motivated systems, valves, hatches and lights open automatically, manually or with a winch. When the valves are opened, an exhaust air flow is formed, with which the combustion products are removed. In systems with artificial motivation, gases are removed from the floor corridors through special mines by forced ventilation. Microprocessor controllers are often used here.
The most important point in the design of these systems is the creation of a complete airtightness of the premises. All engineering communications, staircases, ceilings and other possible sources of leakage should be planned in such a way that when the system is switched on, the polluted air goes only through the smoke removal channels without a suction.
Careful sealing and sealing of all the cracks allows to block the flow of oxygen into the source of ignition, and the removal of smoke contributes to the natural attenuation of the fire.
Special attention is paid to the quality of these systems in buildings that have high explosive hazard categories, as well as in warehouses and storage facilities. Proper smoke protection during a fire saves a lot of lives that could be cut off due to toxic shock or poisoning by products of combustion.
What should I know to develop a protective system at home?
Smoke ventilation can be installed even in your own home, as a rule, this is done in those rooms where there are no windows. It can be used as a normal hood for ventilation. For the hatch device, you need to know the area of the room. The cross-section of the hatch is 0.2% of the area. From the outside of the hatch is installed a valve, and from the inside - a smoke exhaust fan. The valve after installation should work faultlessly.
All parts of the smoke exhaust fan are made of metal, hot air or smoke can not damage them. They are axial and radial, the choice depends on the features of the room. This fan is switched on from the remote control, away from the ventilated room.
