title: Scale-up of stirring as foam disruption (SAFD) to industrial scale.
abstract: Foam disruption by agitation-the stirring as foam disruption (SAFD) technique-was scaled up to pilot and production scale using Rushton turbines and an up-pumping hydrofoil impeller, the Scaba 3SHP1. The dominating mechanism behind SAFD-foam entrainment-was also demonstrated at production scale. The mechanistic model for SAFD defines a fictitious liquid velocity generated by the (upper) impeller near the dispersion surface, which is correlated with complete foam disruption. This model proved to be scalable, thus enabling the model to be used for the design of SAFD applications. Axial upward pumping impellers appeared to be more effective with respect to SAFD than Rushton turbines, as demonstrated by retrofitting a 12,000 l bioreactor, i.e. the triple Rushton configuration was compared with a mixed impeller configuration from Scaba with a 20% lower ungassed power draw. The retrofitted impeller configuration allowed 10% more broth without risking excessive foaming. In this way a substantial increase in the volumetric productivity of the bioreactor was achieved. Design recommendations for the application of SAFD are given in this paper. Using these recommendations for the design of a 30,000 l scale bioreactor, almost foamless Escherichia coli fermentations were realised.
authors.affiliation: Lonza, 3930, Visp, Switzerland. frans.hoeks@lonzagroup.com
authors.forename: Frans W J M M
authors.initials: FW
authors.lastname: Hoeks
authors.forename: Lotte A
authors.initials: LA
authors.lastname: Boon
authors.forename: Fabian
authors.initials: F
authors.lastname: Studer
authors.forename: Menno O
authors.initials: MO
authors.lastname: Wolff
authors.forename: Freija
authors.initials: F
authors.lastname: van der Schot
authors.forename: Peter
authors.initials: P
authors.lastname: Vrabél
authors.forename: Rob G J M
authors.initials: RG
authors.lastname: van der Lans
authors.forename: Waldemar
authors.initials: W
authors.lastname: Bujalski
authors.forename: Asa
authors.initials: A
authors.lastname: Manelius
authors.forename: Gustav
authors.initials: G
authors.lastname: Blomsten
authors.forename: Sven
authors.initials: S
authors.lastname: Hjorth
authors.forename: Giovanna
authors.initials: G
authors.lastname: Prada
authors.forename: Karel Ch A M
authors.initials: KCh
authors.lastname: Luyben
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Nienow
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D003470:Culture Media; D004867:Equipment Design; D005285:Fermentation
chemical_list: D003470:Culture Media