The below should fulfil most requirements to curiosity 

Since oxygen is sparingly soluble in water, it’s one of several growth-limiting factor in fermentations. Though dealing with aerobic microbial applications it helps that the cells, bacteria, yeast, etc are almost indestructible facilitating high RPM, such as up to 2,000 RPM with BactoVessel. 

BactoVessel facilitate aeration / gas injection through a series of 0.5 mm holes arranged in a circle below the primary turbine integrated as a part of the vessel bottom. Number of holes depending on the turbine diameter.

BIG

Ring sparger under Rushton

BIG

Ring sparger in BactoVessel

Four test performed at DTU june-july 2014 based on identical conditions

Turbines tested are Rushton, Jacobs, Smith, Bakker. Air injection (1 litre/min/WV) versus RPM example in a 5.7 litre VV BactoVessel dimension OD150 x 320 mm with 4 litre 5% serum containing media. The SUF is arranged in RUJ and the PCS set at 27°C. 

BactoVessel equipped with classical Rushton turbine. Significant foam production at 500 RPM. At 1000 RPM the foam in seconds blocked the (26 cm2 area) heated exhaust filter after the 15°C warm gas cooler.

• At 0 RPM with OD60 Rushton, 6 blades, marine impeller, 3 baffles
• At 500 RPM with OD60 Rushton, 6 blades, marine impeller, 3 baffles
• At 1000 RPM with OD60 Rushton, 6 blades, marine impeller, 3 baffles

BIG

5.7 BactoVessel Rushton 0 RPM

BIG

5.7 BactoVessel Rushton 500 RPM

BIG

5.7 BactoVessel Rushton 1000 RPM

BactoVessel equipped with an advanced turbine Jacob´s design.

• At 0 RPM,  OD80 Jacobs turbine, 75° angled blades, 8 blades, up-flow, 4 baffles with 2,5 litre/WV
• At 1.200 RPM, OD80 Jacobs turbine, 75° angled blades, 8 blades, up-flow, 4 baffles with 2,5 litre water

BIG

BactoVessel OD130x225 air injection JT8-75 0 RPM

BIG

BactoVessel OD130x225 air injection JT8-75 1200 RPM

BactoVessel equipped with an advanced turbine – Smith design.

Its worth to notice the limited foam generation even at 1000 RPM. Head space is in general free of foam!

• At 0 RPM with OD60 Smith, 6 blades, marine impeller, 3 baffles
• At 500 RPM with OD60 Smith, 6 blades, marine impeller, 3 baffles
• At 1.000 RPM with OD60 Smith, 6 blades, marine impeller, 3 baffles

BIG

BactoVessel 5.7 Smith 0 rpm areation

BIG

BactoVessel 5.7 Smith 500 rpm

BIG

BactoVessel 5.7 Smith 1000 rpm

BactoVessel equipped with the most advanced turbine – Bakker design.

• At 0 RPM with OD60 Bakker, 6 blades, marine impeller, 3 baffles
• At 500 RPM with OD60 Smith, 6 blades, marine impeller, 3 baffles
• At 1.000 RPM with OD60 Smith, 6 blades, marine impeller, 3 baffles