This Small Business Innovative Research (SBIR) Phase I project will explore the fire extinguishing properties of particles smaller than 100 microns. Larger particles that are commonly used in dry powder extinguishers absorb relatively little heat as they pass through a flame, and they extinguish fires chiefly by absorbing heat from the surroundings. Small particles, however, can come to flame temperature and thus remove heat directly from the flame by vaporizing and/or by acting as radiators. They can inhibit flame propagation by providing surface area for free radical recombination. Small particles of calcium bromide may be particularly effective since they will oxidize to calcium oxide and bromine. Calcium oxide will cool the flame by acting as a radiator, and the bromine will inhibit free radical reactions via the same mechanism which makes halons effective fire extinguishing agents. Phase I will address the problem of imparting sufficient momentum to carry small particles to the flame and demonstrate a solution to this problem. With the banning of halons, polar operations and many other activities face severe fire protection problems. Commercial applications are anticipated in these and many other fire suppression situations
