In the present work, an implicit evaporation model for the coherent structures of evaporating sprays is introduced and validated against experimental data of engine combustion network (ECN) spray A. The main aim is to go beyond the limits of standard evaporation models, which are normally based on a dilute spray assumption, and develop a strategy to deal with liquid volume fraction virtually up to one. The proposed method is based on a priori computation of the steady-state equilibrium conditions reached by a system composed by liquid, vapor and air at constant pressure combined with a modeled characteristic time of evaporation. Such equilibrium composition and temperature are then used inside numerical calculations to compute evaporation source terms implemented in an implicit fashion. The new formulation allows simulating evaporation process in the dense zone of the spray, where, due to the extremely low time scales related to mass and heat transfer, classical explicit method usually leads to non-physical results. Such innovative approach has been implemented in a multiphase solver based on the Eulerian-Lagrangian Spray Atomization (ELSA) model in the framework of the computational fluid dynamics (CFD) suite OpenFOAM®. The use of ELSA allows the mass and heat transfer terms to be modeled as a function of the transported amount of liquid-gas interface surface available for evaporation. An analysis of the model performances has been carried out in an URANS framework in order to highlight the physically consistent representation of evaporation phenomena of the approach in the regions characterized by a high liquid volume fraction.