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

Abstract

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.