Transcript Disc Stack Centrifuge Outline Background of centrifugation

Graham Watt
Jackie Ankomah
Dilmini Peiris
Bryan Cawthorn
Background of centrifugation – purpose
Centrifuge designs – different requirements
Disc stack centrifuge technology
Our centrifuge – process
Design choice and sizing
Costing analysis
Downstream processing is a major consideration in
industry
- separation of products/byproducts/wastes
-separation of multiple phases, liquids/solids
Specific to our application, removal of biomass from
production stream
-can be achieved through application of centripetal force
-similar principles to use of settling tank, accelerated
Filters – low solids
concentration
Disc stack centrifuge –
increasing concentration
Decanter centrifuge – higher
concentration
Our Process
- 1% solids **
- 1micron diameter
Courtesy Alfa-Laval, 2008
Subjecting the material to high centrifugal forces denser solids outwards
-causes separation of solid and liquids phases
-allows removal of solids manually, intermittently, or continuously
Courtesy Alfa-Laval, 2008
Centrifugation systems are very sensitive to changes in material composition
- liquid media viscosity will impact settling rate (Stokes’ Law)
- liquid flowrate through centrifuge
- particle size (flocculation interactions)
- cell integrity
- rate limiting steps in process – fermentation of 12 days
Recommendation courtesy Stanley Foster, Alfa Laval
Alfa Laval Culturefuge 400
- Designed to limit cell disruption
- Hermetic seal preventing air/liquid interface
- Allows for necessary throughputs
Courtesy Elsevier, 2008
Liquid Viscosity
– 1.5cP
Particle Diameter
– 1micron
Throughput
– 63.7L/h
Outer disk radius
- 0.75m
Inner disk radius
- 0.5m
Number of disks
- 10
Centrifugation time
- 10 days
Cost estimation
- $80,000
Courtesy Alfa-Laval, 2008
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