Sonochemical reactors: Important design and scale up considerations with a special emphasis on heterogeneous systems

The spectacular effects observed during acoustic cavitation phenomena have been successfully employed for a number of applications on laboratory scale of operation but a well defined design and scale up methodology is lacking. The present work aims at developing a unified approach for the selection of different operating and geometric parameters for large scale sonochemical reactors with a special emphasis on heterogeneous systems. In the case of heterogeneous systems, apart from optimum selection of operating and geometric parameters, it is also important to understand the mixing and hydrodynamic characteristics due to the presence of solid/gas phases in the liquid medium. Also the quantification of attenuation of the incident sound energy has been discussed, which can be important design consideration in heterogeneous systems. Recommendations have been made for optimum selection of frequency of irradiation and power dissipation rate/irradiation intensity as well as the liquid phase physicochemical properties for the given physicochemical transformation. The discussion also highlights' the recent advances in development of sonochemical reactors focusing on reactor geometry and location of transducers in batch and continuous scale of operation. (C) 2010 Elsevier B.V. All rights reserved.