Diffusion equation applied to isothermal drying of a multicomponent liquid film
2005 (English)In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 23, no 11-sep, 1953-1975 p.Article in journal (Refereed) Published
Liquid-side-controlled drying by convection of a multicomponent liquid film is studied. Interactive diffusion in liquid phase is considered the main mechanism for mass transfer. Assuming an isothermal drying process and a constant matrix of multicomponent diffusion coefficients, an analytical solution of the diffusion equation is developed. The equations are decoupled by a similarity transformation and solved by the method of variable separation. The solution is applied to the drying of ternary mixtures, one of them containing a component of negligible volatility. The variation of diffusion coefficients along the process trajectory was taken into account by a piecewise application of the solution in time intervals with averaged coefficients from previous time steps. Despite the simplifications made, the analytical solution gives a god insight into the selectivity of the drying process and is computationally fast. The limitations of the analytical solution and the prospect of applying the solution to the description of a nonisothermal process are discussed. It would introduce an important computational economy since the rigorous treatment of multicomponent drying leads to partial differential equations with variable coefficients, which can only be solved by time-consuming iterative procedures.
Place, publisher, year, edition, pages
2005. Vol. 23, no 11-sep, 1953-1975 p.
multicomponent mixtures, mass transfer, multicomponent drying, selective evaporation, mass-transfer, mixture, diffusivities, prediction
IdentifiersURN: urn:nbn:se:kth:diva-15091DOI: 10.1080/07373930500210416ISI: 000232422200015ScopusID: 2-s2.0-27144436778OAI: oai:DiVA.org:kth-15091DiVA: diva2:333132
QC 20100525 QC 201110172010-08-052010-08-052012-02-20Bibliographically approved