Related Resources: Fluids Engineering
Waste Firewater Volume Excel Spreadsheet Calculator
Contaminated Waste Firewater Volume Excel Spreadsheet Calculator
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In the analysis of fire accidents in process plants, the main attention is usually given to the damages caused by fire to personnel, equipment and structures, while the environmental issues due to contamination by means of polluted firewater are often underestimated, even though they can also lead to severe consequences. A proper design of waste water retention and treatment systems can cope with these issues and the key factor to be evaluated in the design of such system is the actual amount of contaminated firewater to be collected, contained and treated.
Guidelines for firewater design and estimation of maximum firewater demand in process plants are defined in various international and company standards. The amount of firewater to be discharged in the drainage systems and basins is however more complex to evaluate, because the modelling and standardization of the effective duration of a fire and the related consumption of water necessary to fight and extinguish the fire depends on a lot of factors.
Notwithstanding this, criteria for modelling the duration of a fire scenario can be established, starting from assumptions on the amount of flammable/combustible liquids or solids contained in a process unit and taking into account factors like the liquid burning rate, evaporational effects, properly designed fire fighting systems and process isolation devices
The estimation of fire scenario duration leads to evaluate the amount of actual consumed firewater and the results of the analysis may be applied as guidelines for a correct estimation/validation of the size of waste firewater drainage systems and of the capacity of wastewater basins designed to contain firewater.
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