Skip to main content
Fig. 1 | Biotechnology for Biofuels

Fig. 1

From: A microbubble-sparged yeast propagation–fermentation process for bioethanol production

Fig. 1

A prototype microbubble bioreactor for yeast propagation and fermentation. a Schematic representation of the MB bioreactor. The inlet of the fluidic oscillator is constructed to have a decreasing diameter until it reaches the junction with the two outlet tubes, which increase in diameter and are attached to the MB diffusers at the base of the vessel. At the junction, gas (air) entering the fluidic oscillator interacts with one wall and is forced along one of the outlets to emerge from the corresponding MB diffuser. A feedback loop switches the gas flow between the two outlets. A pump (red circle) recirculates culture medium from the base of the fermenter. Images showing b the modified Infors HT fermenter fitted with a recirculation pump; c the moulding (blue) fitted to the concave base of the fermentation vessel to eliminate the dead space and house the MB diffusers; d the sintered stainless steel diffusers and the recirculation tubing; e the fluidic oscillator showing the inlet connected to the gas flow meter on the bioreactor, and two outlets which send a stream of oscillating air, at a defined frequency determined by geometric features of the oscillator and the length of the feedback loop, to prevent the coalescence of bubbles as they emerge from the diffusers

Back to article page