Counterflow diffusion flame burnerFire extinguishing equipment that uses gaseous fire suppressants is provided in computer rooms, communication equipment rooms, libraries, museums, and other places where water damage from firefighting would be disastrous. The production of halon, which had a long history of use as a gaseous fire suppressant, has been banned internationally because it destroys the Earth's ozone layer. Fluorohydrocarbon agents that do not contain bromine or chlorine atom, and inert gases are now being used instead. However, these new extinguishing agents do not perform as well as halon, hence it is very important to ensure that their characteristics are completely understood before using them. Some of them are also known to promote ignition under certain conditions, and cause the release of combustion emissions, such as hydrogen fluoride, that are toxic to the human body.

To ensure the safe use of such fire suppressants, we have conducted research aimed at elucidating their various actions, including the ignition/extinguishing phenomena and processes behind the release of combustion emissions. As part of our basic research on gaseous fire suppressants, we are performing experiments using a counterflow diffusion flame burner and are conducting research in an effort to shed light on the extinguishing performance and extinction phenomenon of various types of fire suppressants on flammable liquids.

We are now seeking to develop a fire extinguishing system that uses nitrogen-enriched air. This system suppresses or extinguishes fires by injecting vast quantities of air that has a high nitrogen concentration (and a low oxygen concentration) into a confined space. We believe this will prove effective in fighting fires at waste treatment facilities and other such locations.

Predictive computer simulation of the concentrarion of nitrogen that will extinguish a fire

Flame extinguishing experiment with nitrogen using a counterflow diffusion flame burner