The existing initial collection efficiency models are designed for downflow filtration.
Alexandre Botari, Luiz Di Bernardo, Angela Di Bernardo Dantas 2015, 'Proposal for initial collection efficiency models for direct granular upflow filtration',Acta Scientiarum: Technologyhttp://186.233.154.254/ojs/index.php/ActaSciTechnol/article/view/24913. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
In this regime, results obtained in cocurrent upflow and downflow are approximately equal.
Wild G., Larachi F., Laurent A. 2006, 'The Hydrodynamic Characteristics of Cocurrent Downflow and Cocurrent Upflow Gas-Liquid-SolidCatalytic Fixed Bed Reactors: the Effect of Pressure Les caractéristiques hydrodynamiquesdes réacteurs gaz-liquide-solide à lit de catalyseur fixe à écoulement cocourant montantet descendant : l'influence de la pression', Oil & Gas Science and Technologyhttp://dx.doi.org/10.2516/ogst:1991022. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)