Effect of screw structure and flared diffuser in a cylindrical venturi-type microbubble generator

The classical microbubble generator of the venturi nozzle type is still used in a wide range of industries despite its relatively low performance. In this study, for overcoming the relatively low performances and maintaining the existing advantages, the cylindrical venturi type of microbubble generators with screw structures and flared diffusers are proposed using conventional 3D printers. In the experimental facility, flow rates and pressure drop were measured. Using high speed images, the performances were deduced for prepared microbubble generators. Based on experimental data, the effect of screw structures for performances of microbubble generators was identified. Furthermore, the flared diffuser to the diffuser of regular venturi nozzle with constant diverging angle were compared. Additionally, synergies are obtained by the screw structure in the flare diffuser. In conclusion, the performances of the venturi type microbubble generator through optimal designed screw structures by 39.4 % were improved.