Chemie Ingenieur Technik
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Network models for capillary porous media: application to drying technology
Porous media are ubiquitous in daily life, ranging from natural materials such as rock, sand, soil or plants to man-made products such as concrete, ceramics, paper, textiles, and various agglomerates for technical, medical or food purposes. In many production processes and applications involving porous materials, the crucial step consists in replacing one pore fluid by a second, immiscible one.
In partially saturated porous media, interfacial, or capillary, effects between the two (or more) phases may play the dominant role for fluid transport and material behavior. For such capillary porous media, the classical approach, which treats the partially saturated body as an effective continuum and describes liquid transport as driven by gradients in average saturation, proves to be inadequate. Pore network modeling is presented as a novel, fascinating opportunity for engineering, providing a virtual micro-lab to study processes involving partially saturated porous media. The approach establishes a link between structural properties of a product and its process behavior; it can connect product quality and process optimization; it brings together chemical and material engineering.
T. Metzger, E. Tsotsas, Chem. Ing. Tech. 2010, 82 (6).