GB1397611A - Fire safety systems - Google Patents

Abstract

1397611 Fire safety system K G SMOKE DISPERSAL Ltd 26 March 1973 [28 March 1972] 14354/72 Heading A5A A fire safety system for a building comprising accommodation units and communal access units includes a plurality of smoke detectors associated with the units, and means responsive to the detection of smoke in one of said units to admit air under pressure to said unit, to restrict the passage of smoke from that unit to other units, and to permit egress of smoke from that unit to the exterior of the building. The building shown in plan in Fig. 1 consists of accommodation units 1 surrounding a central service area comprising staircases 2, lifts 3 and vertical shafts 4, 5, 6, 7, and having access thereto via main corridors 8, 9, 10, 11 provided with self-closing fire doors 14-20 normally held open by electromagnetic locks. Each shaft 4, 5, 6, 7 is pressurised by a fan in the basement, is closed at the top of the building, includes vents opening into the staircases, and has a closable opening on each floor for the passage of air into one of 8, 9, 10 or 11. Smoke detectors are provided in main corridors 8-11, and also in subsidiary corridors 12 and 13 which have smoke vents 21, 22 in their external walls. If smoke is detected in 12 or 13, for example, the speed of the fans in shafts 4-7 increases to increase the air pressure on staircase 2; a vent from shaft 7 to floor level in corridor 9 opens; selfclosing fire-doors 14, 15 close; and vents 21, 22 open. Thus fresh air from 7 drives the smoke along corridors 12, 13 to vents 21, 22 and escapees can reach and use staircase 2 via doors 23, 24. The main corridors 8, 11 and half of 9 and 10 will be safely isloated from those parts of 9 and 10 between closed fire doors 14, 15 and even the latter parts will be usable by escapees heading for doors 23, 24 via fire doors 14, 15. In the modified building of Fig. 2 subsidiary corridors 12 are omitted and four smoke vents are provided in the outer walls of corridors 13. In the Fig. 3 building corridors 13 are also omitted and trunking is included to supply pressurised air to the accommodation units and to clear smoke from the main corridors; each accommodation unit is provided with a smoke vent in an external wall and smoke vents are also provided at the end of the trunking. Fig. 4 illustrates the application of the invention to a building of elongate rectangular floor plan with accommodation units on either side of a single central corridor. Reference is made to divisional Specification 1397612.