Experimental study and numerical validation of a low-energy pilot-scale evaporation unit for treating industrial cleaning wastewater

In this work, a new water-based industrial passive drying system is presented. A pilot-scale unit and its sensor suite are described, and measurements are monitored for a period of one year. Results show that the pilot system is already technically feasible, with an estimated 25% increase in partial vapor pressure difference compared to open air drying, and an average 197% vapor flux increase when compared to a commonly used outdoor water evaporation correlation, with more than 75% of the yearly evaporated mass taking place during summer and spring. A numerical twin of this setup is also presented alongside an averaging process, with satisfactory average vapor flux reproductive capabilities both in 2D and 3D. Complex buoyancy-driven structures are observed, and the vapor flux reproductive capabilities are sensitive to the chosen turbulent Schmidt number. Next steps involve using turbulence models able to describe anisotropic turbulence features, such as the Reynolds Stress Model, to ultimately study design optimizations for the industrial-scale unit through the numerical model. • Pilot-scale solar-driven passive drying system performance evaluated. • Numerical model developed for industrial aqueous waste drying. • Model reproduces observed average system behavior accurately.