NFPA-APSEI Fire & Security 2010

Transcription

1 NFPA-APSEI Fire & Security 2010 Smoke control in industrial buildings Paul Compton, Colt International Ltd

2 A brief introduction Private British Company founded in 1931 Owned by O Hea family and the Colt Foundation (charity) Current Group Turnover 160 million (190 million Euro) Main manufacturing plants in the UK & Holland Represented in Portugal by Colt Portugal S.A. in Lisbon I J O Hea. Colt Founder

3 Introduction Average per year in Portugal: 55,000 fires 51 fire deaths Typically 60% of fire deaths and injuries caused or partially caused by smoke inhalation

4 Regulations in Portugal Smoke ventilation Decreto-Lei nº. 220/2008 Portaria nº. 1532/2008 Despacho nº. 2074/2009 Industrial and warehouse buildings are classified as type XII according to the Decreto-Lei nº.220/2008.

5 Regulations in Portugal Smoke ventilation Type XII buildings with a risk category of 2 o and above require smoke ventilation if: Larger than 400m 2 and Used as a warehouse Design: Should follow an accepted norm Should limit smoke reservoirs to 1600m 2 and 60m length

6 Sprinklers and ventilation SPRINKLERS Will limit fire spread and control growth Will not reduce smoke damage VENTILATION Will prevent smoke logging Assist escape Aid fire fighting Sprinklers are designed to reduce damage, but offer limited benefit to occupants. Smoke ventilation alone will not save the building but is primarily designed to assist escape.

7 What is protected? Life safety by increasing time available for safe evacuation Fire fighters by improving conditions for search ad rescue and fire fighting Property by helping fire fighters, limiting smoke spread, reducing smoke temperatures

8 Smoke spread

9 Components of a system db Y margin

10 Design Norms European CEN/TR British BS and BS American NFPA 204 and many others

11 Example project (Distribution centre) 112 m x 139 m m m to ridge 20.1 m to valley

12 Design process Design process Determine fire size and heat output. Identify clear layer height required. Divide roof space into smoke reservoirs. Calculate mass flow of smoke entering reservoir. Calculate smoke layer temperature. Establish effect of sprinklers on layer temperature, if any. Calculate aerodynamic free area of natural ventilation or extract rate for mechanical ventilation. Calculate plug-holing requirement and calculate number of ventilators. Equipment selection, system design

13 Example project (Distribution centre) 6 smoke reservoirs smoke barriers along red lines down to 19.1m (above racking) Fire (in rack sprinklers): 12MW convective, 6m perimeter

14 Design process Design process Determine fire size and heat output. Identify clear layer height required. Divide roof space into smoke reservoirs. Calculate mass flow of smoke entering reservoir. Calculate smoke layer temperature. Establish effect of sprinklers on layer temperature, if any. Calculate aerodynamic free area of natural ventilation or extract rate for mechanical ventilation. Calculate plug-holing requirement and calculate number of ventilators. Equipment selection, system design

15 Components of a system STEADY STATE Mass in = mass out Heat in = heat out = mass flow rate here Account for sprinkler cooling by limiting smoke layer temperature to sprinkler bulb temperature Mass flow Mass flow rate here = 99 kg/s Calculated smoke temperature = 135 o C Ceiling sprinkler temperature = 141 o C

16 Design process Design process Determine fire size and heat output. Identify clear layer height required. Divide roof space into smoke reservoirs. Calculate mass flow of smoke entering reservoir. Calculate smoke layer temperature. Establish effect of sprinklers on layer temperature, if any. Calculate aerodynamic free area of natural ventilation or extract rate for mechanical ventilation. Calculate plug-holing requirement and calculate number of ventilators. Equipment selection, system design

17 Components of a system Area depends on mass flow rate, smoke depth and smoke temperature mass flow rate Also upon ratio of inlet to exhaust Depth (3.5m) Aerodynamic area = 21.9 m 2 Minimum number of ventilators = 2 (4 chosen) (for each reservoir 1.3% roof area equivalent)

18 Typical equipment

19 Product certification

20 Maintenance SHEVS need maintenance and testing Typical regime Test weekly or monthly and inspect/maintain annually Yes it costs time and money but it provides confidence and awareness

21 Conclusion What conditions do you want for escape and fire fighting? A properly designed smoke ventilation system can save lives and property is a cheap system a false economy?

22 NFPA-APSEI Fire & Security 2010 Smoke ventilation in industrial buildings The End Thank End You Thank you