Inclusion of the sorption hysteresis phenomenon in future drying models. Some basic considerations
Fuente:
Redalyc
Guardado en:
| Autor principal: | |
|---|---|
| Formato: | Artículo científico |
| Lenguaje: | en |
| Publicado: |
Universidad del Bío Bío
2011
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1876434680661671936 |
|---|---|
| author | Jarl-Gunnar Salin |
| author_facet | Jarl-Gunnar Salin |
| contents | Inclusion of the sorption hysteresis phenomenon in future drying models. Some basic considerations Jarl-Gunnar Salin Agrociencias Modelling wood drying sorption hysteresis The sorption hysteresis effect, i.e. different wood equilibrium moisture contents (EMCs) in desorption and adsorption for the same relative humidity, is well known. However, quantitative sorption isotherms, in the form of tables or analytical correlations, are almost always given as the average of the desorption and adsorption curves. Consequently most drying simulation models use these average curves, and does not take into account the sorption hysteresis phenomenon. The equilibrium state of a wood sample is thus not a function of the relative humidity only, but depends on the moisture history also. This means that Fick's equations - with moisture content as a single driving force - are not valid any more. For a pure desorption process the state of the sample follows the desorption isotherm, but a problem arises when desorption is followed by adsorption - as for instance in the timber conditioning phase. It seems reasonable to assume that for each EMC point, on or between the desorption/adsorption isotherms, the moisture content change follows a unique path when the surrounding climate changes. This path - the so called scanning curve - does not need to be the same in desorption and adsorption. Some selected results and corresponding scanning curve suggestions are presented and discussed. Drying models with the sorption hysteresis phenomenon included should be developed for the analysis of experimental data and more generally for use as an improved tool in practical applications. 2011 artículo científico 0717-3644 https://www.redalyc.org/articulo.oa?id=48519399005 en http://www.redalyc.org/revista.oa?id=485 Maderas. Ciencia y Tecnología application/pdf Universidad del Bío Bío Maderas. Ciencia y Tecnología (Chile) Num.2 Vol.13 |
| format | Artículo científico |
| id | redalyc_48519399005 |
| institution | Redalyc |
| language | en |
| publishDate | 2011 |
| publisher | Universidad del Bío Bío |
| spellingShingle | Inclusion of the sorption hysteresis phenomenon in future drying models. Some basic considerations Jarl-Gunnar Salin Agrociencias Modelling wood drying sorption hysteresis Inclusion of the sorption hysteresis phenomenon in future drying models. Some basic considerations Jarl-Gunnar Salin Agrociencias Modelling wood drying sorption hysteresis The sorption hysteresis effect, i.e. different wood equilibrium moisture contents (EMCs) in desorption and adsorption for the same relative humidity, is well known. However, quantitative sorption isotherms, in the form of tables or analytical correlations, are almost always given as the average of the desorption and adsorption curves. Consequently most drying simulation models use these average curves, and does not take into account the sorption hysteresis phenomenon. The equilibrium state of a wood sample is thus not a function of the relative humidity only, but depends on the moisture history also. This means that Fick's equations - with moisture content as a single driving force - are not valid any more. For a pure desorption process the state of the sample follows the desorption isotherm, but a problem arises when desorption is followed by adsorption - as for instance in the timber conditioning phase. It seems reasonable to assume that for each EMC point, on or between the desorption/adsorption isotherms, the moisture content change follows a unique path when the surrounding climate changes. This path - the so called scanning curve - does not need to be the same in desorption and adsorption. Some selected results and corresponding scanning curve suggestions are presented and discussed. Drying models with the sorption hysteresis phenomenon included should be developed for the analysis of experimental data and more generally for use as an improved tool in practical applications. 2011 artículo científico 0717-3644 https://www.redalyc.org/articulo.oa?id=48519399005 en http://www.redalyc.org/revista.oa?id=485 Maderas. Ciencia y Tecnología application/pdf Universidad del Bío Bío Maderas. Ciencia y Tecnología (Chile) Num.2 Vol.13 |
| title | Inclusion of the sorption hysteresis phenomenon in future drying models. Some basic considerations |
| topic | Agrociencias Modelling wood drying sorption hysteresis |
| url | https://www.redalyc.org/articulo.oa?id=48519399005 |