Tank fire extinguishing

This program combines the following calculation functions comprehensively. In particular, the calculations regarding bubble development speed and bubble loss are based on an experimental report called FOAM SPEXS conducted by a research institution in Sweden.

• "Calculation of the flight path of bubbles emitted from a bubble discharge nozzle" and "Calculation of the loss of bubbles in flight"
• "Radiation intensity calculation" for safety checks for firefighters and foam cannon installation.
• "Calculation of foam loss by calculating the rising airflow velocity" generated above the liquid surface in a tank fire.
• Estimating the time it takes to establish the first bridgehead if the bubbles that reach the combustion liquid surface do not disappear.
• "Calculation of fire extinguishing time" based on foam deployment.

Use the 3D viewer to make simulation results more "realistic".

By using the dedicated "FM Viewer," you can freely manipulate the simulation results on your PC. You can pinpoint and zoom in on the area you want to see, dramatically improving your understanding of the analysis accuracy compared to conventional still images.

Services offered: Tank fire extinguishing / Radiant heat calculation / Water and foam discharge

Further details are explained on the FM Viewer introduction page.

FM Viewer

Effective placement of foam

The foam released from the foam nozzle is strongly affected by wind, resulting in losses due to scattering during flight. On the other hand, a strong updraft is generated at the tank fire surface due to combustion, and the updraft becomes stronger as you move from the edge of the tank towards the center. Also, the updraft velocity is not large at heights just above the combustion surface, but the updraft velocity increases as you go higher above the combustion liquid surface. Therefore, the most effective placement of foam is either at the edge near the circumference of the tank or at heights just above the combustion liquid surface.

When foam is introduced into the sweet spot, it reaches the surface of the burning liquid, but because the temperature of the burning liquid is high, the foam evaporates and disappears. However, if foam is continued to be introduced, the liquid surface in that area cools down and foam begins to accumulate. This initial accumulation of foam is called the "foam bridgehead." From this bridgehead, the foam then expands across the burning liquid surface, eventually leading to fire extinguishing. Of the total fire extinguishing time, the time spent establishing the foam bridgehead is the longest, and the foam's expansion, depending on the foam introduction speed, is relatively short.

The diagram on the left shows the process of creating a foam bridgehead. The intensity of the fire will not change until the foam bridgehead is established.
The diagram on the right shows a situation where foam has begun to spread across the surface of the burning liquid, partially extinguishing the fire. Radiant heat is also decreasing accordingly.