Experimental study of an air assisted mist generator

This paper presents the results of an experimental study of a twin-fluid internally mixed mist generator. In this type of mist generator, atomization is attained by injecting a small amount of compressed air into a liquid stream in a mixing chamber inside the mist generator. Since most of the energy for atomization is supplied to the liquid by the atomizing air, a significantly small pressure drop can produce a fine spray. The dependence of droplet size upon the liquid supply pressure and the air liquid mass ratio was studied in detail using a Malvern Particle size analyzer. The results presented in this paper suggest that the investigated injector could be used to control the flow rate (mist through put) and spray characteristics independent of each other by simultaneously varying the supply pressure of the liquid and the atomizing air. The controlled atomization reported in this paper for a twin-fluid internally mixed atomizer makes it attractive to be used for fire suppression applications in particular because of the high mist generation rate and for various other commercial applications in general, as the atomizer is capable of providing spray of different characteristics depending upon the application requirements.