FEIT Research Project Database

Combining centrifugation and filtration to minimise cake cracking

Project Leader: Anthony Stickland
Staff: Anthony Stickland
Collaborators: Herman Nirschl (Karlsruhe University)
Primary Contact: Anthony Stickland (stad@unimelb.edu.au)
Keywords: deformability; separation processes; Solid-Liquid Systems
Disciplines: Chemical & Biomolecular Engineering
Domains: Convergence of engineering and IT with the life sciences
Research Centre: Particulate Fluids Processing Centre (PFPC)

A range of methods can be used by to desaturate suspensions, including evaporative processes such as solar or thermal drying and mechanical processes such as centrifugal, vacuum and positive pressure filtration. Evaporation is energy intensive and not useful for thermally-sensitive materials such as some pharmaceuticals and food products. Vacuum and pressure filtration have the disadvantage that the filter cake can crack, which hinders the desaturation. Centrifugal filtration, on the other hand, produces limited cracking since the body force is continuously acting on the liquid and the desaturation is not affected by fingering instabilities.  However, there is a residual saturated part of the cake next to the bowl wall where the centrifugal acceleration cannot overcome capillary forces. The hypothesis of this project is that the application of a vacuum or positive pressure after centrifugal filtration is the optimum means for mechanically desaturating suspensions. This will be tested experimentally and theoretically. This project is being conducted in collaboration with Karlsruhe Institute of Technology in Germany.