Fire Safety Science Digital Archive

Tests have been carried out in which water sprays, initially at room temperature and ranging in drop sizes from 0.3 to 1. 7mm and in delivery rate from 0 - 2.0 g.cm-2 min-1 were applied to two kerosine fires burning in vessels 11 and 30 cm diameter. With the larger fire the pressure at which. the spray was produced varied between 5-85 Ib/in2. In general the temperature a little below the surface of the kerosine reached a steady value ? lower, than the temperature which would have been reached without spraying. ? decreased as the flow rate reaching the kerosine surface increased. The flow rate required to reduce ? to the fire point, under which conditions extinction took place, was approximately proportional to the drop size of the spray and independent of the size of the fire. ? did not depend noticeably on the pressure at which the spray was produced. Some conditions of spraying brought about a marked intensification of the fire by splashing and gave rise to high values of ?. The phenomena observed have been discussed on the basis of a heat balance between the heat entering the liquid from the flames and the heat passing from the liquid to the spray drops.