Droplet atomization and evaporation in dense sprays is relevant to several physical applications. We report a population balance model wherein these processes are handled simultaneously. The model is implemented in an Eulerian-Eulerian multiphase framework wherein the drop phase is itself modeled as multiple continua. The continuum model of the drop phase allows us to incorporate a stress field which naturally arises in a collision dominated dense spray. The utility of the model is first demonstrated on a uniform flow evaporator, wherein the mean droplet surface area is shown to exhibit a similarity scaling in terms of a nondimensional parameter that characterizes the competition between atomization and evaporation. The model is then generalized to a computational fluid dynamics (CFD) situation wherein a plug flow atomizer/evaporator is studied. The continuous variation of Sauter mean diameter (SMD) in the flow is presented wherein atomization processes cause the SMD to decrease while evaporation processes cause the SMD to locally increase. This is due to the preferential disappearance of the smaller size drops. Finally, the utility of the model for studying dense droplet ensemble atomization, evaporation, and combustion is discussed.