Revisiting ‘penetration depth’ in falling film mass transfer
| Autor: | Mohammad Ali Aroon, Saeed Shirazian, Milad Asgarpour Khansary |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Absorption (acoustics)
Materials science 020209 energy General Chemical Engineering Observable 02 engineering and technology General Chemistry Mechanics Thermal diffusivity Boundary layer 020401 chemical engineering Condensed Matter::Superconductivity Mass transfer 0202 electrical engineering electronic engineering information engineering 0204 chemical engineering Diffusion (business) Penetration depth Falling (sensation) |
| Zdroj: | Chemical Engineering Research and Design. 155:18-21 |
| ISSN: | 0263-8762 |
| DOI: | 10.1016/j.cherd.2019.12.023 |
| Popis: | For the analysis of falling film mass transfer such as gas absorption in liquid phase flowing over a vertical wall, conventionally an infinite penetration depth for penetrating component has been assumed. This assumption is originated from the fact that magnitude of diffusion depth is too small relative to the film thickness as if the mass transfer into the liquid film is taking place in a semi-infinite geometry. Despite its validity in the most engineering applications, it is still an unanswered question that ‘to what physically meaningful extent the diffusion may occur or the mass transfer boundary layer into the liquid film could progress alongside the wall, and consequently how it might affect the mass transfer characteristics’. We addressed such concern here by considering a finite depth of penetration into the film, derived governing equations for the continuity of mass and solved it analytically and numerically. The progress of penetration depth over the vertical coordinate i.e. flowing direction of falling film is observable as it approaches the film thickness far down the wall. The method gives the opportunity to examine the progress of the penetration depth with mass transfer properties such as diffusivity, average liquid velocity and etc. which have not been touched before. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |
Full Text from ScienceDirect