Yiotis Andreas G, Tsimpanogiannis Ioannis N, Stubos Athanassios K, Yortsos Yannis C
National Center for Scientific Research Demokritos, Aghia Paraskevi 15310, Greece.
J Colloid Interface Sci. 2006 May 15;297(2):738-48. doi: 10.1016/j.jcis.2005.11.043. Epub 2005 Dec 15.
We study the periods that develop in the drying of capillary porous media, particularly the constant rate (CRP) and the falling rate (FRP) periods. Drying is simulated with a 3-D pore-network model that accounts for the effect of capillarity and buoyancy at the liquid-gas interface and for diffusion through the porous material and through a boundary layer over the external surface of the material. We focus on the stabilizing or destabilizing effects of gravity on the shape of the drying curve and the relative extent of the various drying periods. The extents of CRP and FRP are directly associated with various transition points of the percolation theory, such as the breakthrough point and the main liquid cluster disconnection point. Our study demonstrates that when an external diffusive layer is present, the constant rate period is longer.
我们研究了毛细管多孔介质干燥过程中出现的阶段，特别是恒速阶段（CRP）和降速阶段（FRP）。采用三维孔隙网络模型对干燥过程进行模拟，该模型考虑了液 - 气界面处的毛细作用和浮力效应，以及通过多孔材料和材料外表面边界层的扩散。我们关注重力对干燥曲线形状和各个干燥阶段相对程度的稳定或不稳定作用。CRP和FRP的程度与渗流理论的各种转变点直接相关，如突破点和主要液体团簇断开点。我们的研究表明，当存在外部扩散层时，恒速阶段会更长。
