Yukio Yamauchi

Validating the Function of Absorber Plates for Auto-sprinkler System Activation

Building codes in many countries require an absorber plate with an auto-sprinkler system to accelerate sprinkler system activation when this system cannot be installed on a ceiling. This study evaluated experimentally the function of absorber plates. A sprinkler with or without an absorber plate was installed in a room measuring 4.3(L) × 3.0(W) × 3.3(H) m. Hanging walls 1.1 m long were installed at the edges of the room ceiling to help form a hot smoke layer during a fire. Heptane and methanol into circular pans with diameters of 20–60 cm were the fire sources. The fire sources were positioned at the room center and 0.5, 1, and 1.5 m from the room center to produce fire plumes that reached both the sprinkler head and absorber plate, directly reached the absorber plate but not the sprinkler head, or reached neither the sprinkler head nor absorber plate, respectively. Temperature and velocity, two parameters important to sprinkler activation, were measured near the sprinkler head and compared for cases with and without an absorber plate. Experimental data indicate that the absorber plate did not help accelerate sprinkler head activation from temperature and velocity measurements for all cases with and without an absorber plate.

Computer Geometry Applied To Locus Approach To Fire Stations

The diagram of influence for the fire-extinguishing activity of a fire station is repre sented by various Voronoi diagrams of the fire station. The ordinary Voronoi diagram, the network Voronoi diagram, high order network Voronoi diagram and the weighted network Voronoi diagram are introduced and defined for use in firefighting strategy. The Voronoi diagrams of the fire stations have been calculated and drawn on the personal computer from the actual city-map data of the metropolitan district in Japan. The reasonable scopes of influence for the fire-fighting of the fire stations are represented by the ordinary Voronoi diagram and the locus problems of the fire stations in the provincial towns may be estimated by the calculational result of ordinary Voronoi diagram. However, the locus problem in the metropolitan area must be estimated by the network Voronoi diagram in due consideration of the traffic congestion. In the fire-fighting strategy, the calculational results of the high order weighted network Voronoi diagram of the fire station may be capable to the dynamic allocations of the fire engines from the fire station to fire scene and to other fire station at the traffic snarl and the lane loading in the metropolitan district.