Experimental investigation of vortex structure formation in a gas-vortex bioreactor

The formation of circulation vortex cells in a liquid medium of a gas-vortex bioreactor has been experimentally studied. The study was carried out in an industrial glass bioreactor with a volume of 10 liters and a reactor vessel diameter D = 190 mm. The vortex motion of air was generated by a vane wheel (activator) when 50 and 80% of the reactor vessel was filled with the model medium. A 65% water solution of glycerol with density ρ = 1150 kg/m 3 and kinematic viscosity ν = 15 mm 2 /s was used as a model medium. To observe the pattern of vortex motion, the method of particle image velocimetry (PIV) was used. It is shown that when the activator rotates, the meridional and circulation motions of liquid occur simultaneously. Regularities of the vortex motion of the model medium are determined depending on the reactor filling and the intensity of activator rotation. It is found that the cells of centrifugal circulation appear under the interface; with an increase in the activator rotational speed they develop into the depth of the reactor. It is established that centrifugal circulation of liquid develops similarly as it takes place in a circulating vortex flow of one liquid and in a system of confined vortex motion of two immiscible liquids.