Novel Three-Dimensional Cut Umbrella-like Evaporator with Four Angle-Adjustable Evaporation Surfaces in a Submersible Floatation State for Enhanced Seawater Desalination
Dahang Deng, Qian Liang, Caiyi Guo, Changkun Liu
Abstract
Solar-driven evaporators provide ecofriendly and efficient solutions for purifying seawater. This study developed a novel three-dimensional (3D) cut umbrella-like evaporator (CUL-evaporator) featuring four angle-adjustable evaporating surfaces incorporating cross-linked poly(vinyl alcohol) (PVA) and reduced graphene oxide (rGO) into cotton fabric. Notably, the CUL-evaporator with less production material outperforms the full umbrella-like evaporator (FUL-evaporator) in terms of the evaporation rate and pure water production. This superior performance results from the effective utilization of the back sides of the evaporating surface for water evaporation. When positioned at a 22.5° angle, the CUL-evaporator achieved a high evaporation rate of ∼3.45 kg h –1 m –2, benefiting from the gravity-assisted water transport. Furthermore, it performed consistently over 7 days, maintaining an evaporation rate of 3.36 kg h –1 m –2 using simulated seawater (3.5 wt %). The CUL-evaporator also exhibited excellent stability, preventing salt accumulation on the evaporating surface, even with high-concentrated salty water (20 wt % NaCl). Leveraging these characteristics, an outdoor submersible floatation evaporator installation was designed and achieved substantial water production of 7.63 L m –2 within 8 h. This study presented a novel design model for 3D evaporators, offering an effective approach for long-term, stable, and salt-resistant evaporation processes.