Heat Release Rate
The single most important variable when it comes to fire is the heat release rate (HRR). This refers to the expenditure of energy unleashed in a fire event or can be referred to as the energy released while burning per unit of time. This critical concept is what governs fire safety as it is directly correlated to how fast a fire would spread and the potential damage it may cause to life and property. It governs all aspects of a fire, from initial smoke development to a full fledge raging inferno that can cause structural failures and the collapse of buildings and infrastructures. The more energy that is being released during combustion the more destructive and powerful a fire can be.
The development of a fire would rely on few key factors starting with the growth phase as the fuel type and the area ventilation will decide whether the fire will grow bigger or be self-contained. Fire needs oxygen and fuel to sustain its path and the heat release rate is directly correlated to these two. Advanced phase is when the fire has reached its peak. This stage is when the fire has consumed most of the available fuel and the only way it is being kept from progressing further is the available oxygen supply. The decay phase is when the heat release rate (HRR) rapidly declines as the fuel and oxygen are fully depleted. This last phase continues until the HRR is close to zero and the fire dies down as it burn itself out when it doesn’t have fuel, oxygen and surrounding heat to sustain the combustion.
The importance of knowing the heat release rate of a fire is critical as this parameter governs how destructive a fire can be. It is not the temperature per se nor the shape of the flame that would determine the extensiveness of the damage but the energy that is released during combustion. HRR is measured in units of watts (W), kilowatts (kW) or megawatts (MW). Wildfires are intense and uncontrollable with potential for vast destruction. The HRR of this type of inferno is typically in the range between 1,000 – 20,000 kW depending on various factors. Wildfires are not compartmentalized as the fire spread freely and is not contained to a specific location. Fuel consumed in this type of fire are also cellulosic in nature like natural vegetation, paper, timber and the likes, henceforth it would pale in comparison to industrial fires which can reach the megawatts (MW) scale of heat release rate. A high fuel load in the case of pool fires means that the HRR is of megawatts (MW) scale in proportion. Hydrocarbons like gasoline/petrol, diesel and jet fuel have relatively high heat of combustion while having greater than 90% in burning efficiency. The energy expenditure is of the top level as the typical gasoline pool fire would release more than 600MW of thermal energy. Jet fires due to its being high pressured with explosive flames will have the level of heat release rate (HRR) of more than 450 megawatts (MW).
Patsum Insulation has a variety of fire-resistant insulation materials. Our mineral wool is certified as Class A non-combustible with the maximum temperature of up to 1000°C. They are used as a fire-stop barrier for perimeter compartmentation and has been specified in various commercial and industrial projects for firesafing, which is the term for the installation of non-combustible insulation materials in fire-rated assemblies. Our material complies with ASTM E-84 https://www.astm.org standard and tested with a flame spread index (FSI) of 0-25 and smoke developed index (SDI) that is equal to or less than 450.
