Wood Scrolls as Highly Efficient All‐Day Steam Generators

Abstract A novel all‐day evaporator in the form of a scroll is developed by rolling a thin layer of wood. Two different wood layers are used to fabricate a wood scroll with diagonal natural water channels (d‐WS) and a wood scroll with parallel natural water channels (p‐WS). Because only diagonal channels allow water transport across the wood layer, d‐WS exhibits good lateral water transport, whereas p‐WS exhibits poor lateral water transport. The gap channels (i.e., spaces between the overlapping wood layers) facilitate vertical water transport in both d‐WS and p‐WS. The synergistic effect of the gap channels and diagonal channels in d‐WS allows for a uniform water flow and sufficient water transport to the top and side surfaces, thus simultaneously increasing evaporation performance and salt resistance. The total evaporation rate of water of d‐WS is 9.08 kg m −2 h −1 in the absence of wind, which increases to 37.95 kg m −2 h −1 in the presence of 2 m s −1 wind. These evaporation rates are among the highest values ever reported under similar conditions. The evaporation rate of d‐WS does not deteriorate even after 5 d, demonstrating the possibility of long‐term operation.