Optical method for porosity determination to prove the stamp effect in filter cakes
| Autor: | Thomas Becker, Martina Gastl, Martin Hennemann |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
04 agricultural and veterinary sciences Compression (physics) 040401 food science law.invention Volumetric flow rate ddc Filter cake 03 medical and health sciences 0404 agricultural biotechnology 0302 clinical medicine law 030221 ophthalmology & optometry Surface roughness Skin effect Composite material Porosity Layer (electronics) Filtration Food Science |
| Popis: | During lautering, a filtration process in beer production, an inhomogeneous filter cake composed of different horizontal layers is formed. Fine particles settle slower than coarse particles and form a layer on top of the cake. Due to its low permeability, the fine layer acts as a stamp on the compressible bottom layer, thus resulting in cake compression and reduced flow rate (stamp effect). A method to prove the stamp effect and investigate its impact on the filtration was developed. The structure of the cake was preserved by freezing, which enabled sampling from different layers at different filtration times. An optical porosity determination (surface roughness) was established to study the compression. A predominant impact of the stamp effect compared with a less pronounced skin effect was shown. To avoid the stamp effect during filtration, a filtration technique was developed, which includes the removal of fines from the filter cake. |
| Databáze: | OpenAIRE |
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