Dewatering of slurry with poor filterability in basket centrifuge: discharge of supernatant using bypass filter medium
When centrifugal dewatering in basket centrifuge involves the sedimentation of particles in feed slurry, the slurry separates into two phases: supernatant and cake. The dewatering proceeds as the supernatant permeates through the cake. However, if the cake formed has poor permeability...
| Main Authors: | , , , , |
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| Format: | Conference or Workshop Item |
| Language: | English English |
| Published: |
2015
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/42381/ http://irep.iium.edu.my/42381/ http://irep.iium.edu.my/42381/1/FILTECH_2015_ALVIN_GINTING_FULL_PAPER.pdf http://irep.iium.edu.my/42381/4/FILTECH_2015_-_Conference_Programme.pdf |
| Summary: | When centrifugal dewatering in basket centrifuge involves the sedimentation of
particles in feed slurry, the slurry separates into two phases: supernatant and cake.
The dewatering proceeds as the supernatant permeates through the cake. However, if
the cake formed has poor permeability, it takes longer time to reach the desired
moisture content. In this study , a new method is proposed to dewater slurry which
forms cake with poor permeability and a comparison was made with the conventional
design. In the proposed design, the filter media is placed not only on the circuit, but
also at the bottom of the filter chamber. Thus, even though the cake formed has a high
hydrodynamic resistance, the supernatant could be discharged because the filter
medium at the bottom has less hydrodynamic resistance than the cake and therefore
works as a bypass. It is known from the previous study that when the supernatant is
totally discharged, the cake will undergo a consolidation process, which will make the
cake more compact. Therefore, it is postulated that the bypass filter medium would
improve the dewatering efficiency drastically. The results obtained is that the
supernatant still remained in the filter chamber even after 300 s of dewatering when
the conventional design was used, while the supernatant was completely discharged
within 150 s when the new design was used. Thus, it can be concluded that the filter
medium at the bottom of the filter chamber worked as a bypass and improved the
dewatering performance. |
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