Smoke and Fire Curtains
The fire curtains are electrically operated roller blinds that have been developed over the years to become fire or smoke barriers. The steel and the curtain have been selected to meet the demanding standards required to meet the BS 476 Part 22.
Fire curtains require a pair of side guides attached to the wall for the curtain to descend into and then to rest securely on the floor, restricting the passage of fire.
Smoke curtains do not require side guides and may allow some egress of smoke at the corners or edges. An over-lapping system is used to reduce this effect. Employed in many modern buildings and are used in the event of a widespread fire to restrict the lateral spread of smoke and hot gases along the underside of a roof, ceiling or balcony.
A term that has different meanings to all manufacturers of fire curtains. Generally meaning that once all source of power has been cut off then the battery back up to the fire curtain will allow the curtain to descend immediately once the power has been cut, in a controlled descent.
Controlled descent can be achieved either by means of a heavy bottom bar and a back current, emf, through the tubular motor or a gear driven motor will also descent in a controlled manner so that injuries are not caused when the curtain descends.The control panel incorporates a battery back up system as standard.
The successful application of shevs ( Smoke and Heat Exhaust Ventilation Systems ) is to create a smoke free zone above the floor level by the use of various means. Exhaust ventilation systems and natural ventilation, automatic curtains to create compartments and fire walls all assist to reduce damage to contents & building, delay the spread of fire and allow access for escape and for fire fighters.
The automatic curtains are a critical part of the equation and if they fail then the shevs system will not function efficiently or as designed. This is why the fail safe system is most important.
But as long as the curtains are strategically positioned and are functional then the fire will be retarded and fumes will be contained to an extent, allowing some time to escape from the scene.