General methods to improve DO level in fermentation are modification of mixer configurations, increase of stir speed and installation of jet-tube air sparger, etc. The former two either requires a big investment or increases operational cost; The latter demands a high pressure head to achieve high jet flow speed, increasing power consumption of air compressors. At the same time, high speed flow causes shear damage of certain cells, extends batch cycle, affects target yield; and it has a complex structure with excessive connectors, thus is prone to contamination with limited applications. Vortex Gas-liquid Mixer is a new type energy-saving air sparger, and it has many merits including good performance of air dispersion, deep gas-liquid blending and good production adaptations, etc.
Vortex G-L mixer has inner and outer shell. Air enters the inner shell, transformed to a high speed vortex flow vie guide vane, simultaneously, generated negative pressure drags broth into mixing aisle between shells, then air is dispersed completely by dynamic emulsification effect in the spiral flow way before jetting out .
The basic principle of vortex G-L mixer is energy conversion between static pressure and kinetic pressure of compressed air, air injection drives surrounding broth, and transforms it to a high-speed rotating biphase flow. The process of vortex mixing raises bubble residence time, increases air & liquid interface areas, and improves sterile air utilization rate.
1 Easy installation. Vortex gas-liquid mixer directly replace existing annular air sparger.
2 Complete gas-liquid blending at the bottom of the fermentor. Dispersed air bubbles have small diameters; DO level increases by 5% ~ 20%; better air utilization.
3 Mild mechanical interactions between cells during mixing. Target yield increases steadily.
4 Concise structure comparing to jet-tube sparger, easy to clean, free of contamination.
5 Low resistance, low demand for driving pressure head, no extra increase of compressor load or power consumption.
6 Vortex gas-liquid mixer serves not only as an air sparger, but also a bottom stirrer. In coordination with mixing system, or draft tube modification, traditional stirring can be simplified or even cancelled. It can also be used in new-type ALR.