Experimental measurements on the microbubble characteristics and dissolved oxygen (DO) in water using single and twin-Venturi type microbubble generators

The aim of this paper is to develop low cost and low power consumption microbubble generator to improve the mass transfer of gas to liquid. Microbubble aeration used in aquaculture to improve dissolve oxygen level, water recycling through dissolved air flotation (DAF), oil refinement and reduction of skin friction on ship Hull. A single Venturi and 3 twin-Venturis microbubble generators are manufactured and tested in this study. Experi-mental data on microbubbles diameters distribution and dissolved oxygen are presented. The main conclusions are: i) the mean microbubbles diameters produced by twin-Venturi are smaller by 10 & mu;m than single Venturi generator; ii) the dissolved oxygen concentration was higher for twin-Venturi microbubble generator; iii) the microbubbles size distribution from twin-Venturis have a narrower distribution which reduces the probability of bubbles coalesce as they have very close values of velocities; iv) the bubbles diameters and velocities increase with the height in the water tank.