Spray quenching

Abstract

AbstractA study was made of spray quenching by high velocity gas atomization. A mathematical model of both high and low temperature spray quenching was developed. Data were taken for proving and validity of the model.Experiments were performed on a vertical downward flow of air‐water in a 1.0 in. diameter tube. Injection was by either of two modes. The first was a set of six peripheral liquid jets projecting water perpendicularly into the high velocity airstream. The second mode of liquid injection was by means of a 360° peripheral, annular slot, which laid down a continuous wall film at the point of injection. Air velocities of 430 and 200 ft./sec. and liquid injection rates of from 150 to 1,200 ml./min. were studied. The following physical quantities were measured: liquid fluxes, wall film flow rates, drop size distributions, and median drop size. An attempt was made to measure gas temperature in a dense spray by using two different types of temperature probes, but only liquid temperatures could be detected. A comparison of data with published data and correlations was made.The best quenching conditions obtained were a liquid‐to‐gas mass ratio of 0.25, a Sauter mean drop diameter of 45 μ, and an indicated characteristic quench time of 10−3 sec.