Effect of an Obstructed Ceiling on the Activation Time of a Residential Sprinkler

摘要

A series of 45 experiments were conducted to compare the effects of two different211u001eceiling configurations on the activation times of a quick response to residential 211u001ependent sprinkler. The two ceiling configurations consisted of a smooth 211u001ehorizontal unobstructed ceiling and a horizontal ceiling obstructed by parallel 211u001ebeams measuring 0.038 m (1.5 in) wide by 0.24 m (9.5 in) deep and spaced 0.41 m 211u001e(16 in) on center. For each of the two ceiling configurations, the fire source, a 211u001ecomputer controlled methane gas burner, was placed in three different locations 211u001ewithin the fire compartment and 2.1 m (7 ft) below the ceiling. Additionally, for 211u001eeach burner location, the flow of methane gas to the burner was supplied in such 211u001ea way as to give three different fire growth scenarios. For the smooth horizontal 211u001eunobstructed ceiling three experiments were performed for every burner position 211u001eand fire growth rate. For the horizontal obstructed/beamed ceiling there were two 211u001eexperiments for every burner position and fire growth rate. Measurements taken 211u001einclude the time to sprinkler activation, temperature and velocity of the ceiling 211u001ejet at the sprinkler of activation, and temperatures and ceiling jet velocities 211u001eat various other locations and elevations within the fire compartment.