Fire Safety Science Digital Archive

The entrained air velocity, mass median drop size, drop size distribution and drop velocity of sprays falling on a given area, and produced by a battery of impinging jets, have been related to the diameter of the jets, the pressure at the jets and the rate of flow of spray to the given area. A theoretical formula has been derived for predicting the entrained air velocity in the sprays which agrees fairly well with the formula actually obtained. The application of the theoretical formula to predict the entrained air velocity and reach of sprays from single pressure nozzles is discussed. It was also found that the rate of reduction in drop size with increase in pressure, decreased as the pressure increased.