The main goal of this work is to investigate the performance of an AA system at lab-scale under conditions as close as possible to those prevailing under containment venting in a nuclear reactor. To achieve this goal the following specific stages have to be followed: a) to adequately design, develop, set-up and integrate an AA system at 21 kHz in an experimental facility for the generation and characterization of aerosols; b) to measure the aerosol growth and precipitation before and after ultrasonic agglomeration and c) to find out the best operational conditions of the AA system to work with aerosols taken as a model of those present in accident scenarios. Two power ultrasonic plate transducers tuned at 21 kHz and operated at 300W have been located along the vertical axis of an agglomeration chamber to generate an intense ultrasonic standing wave field perpendicular the gas flow. The averaged value of the sound pressure level measured inside the AA chamber was 155 dB. The experimental tests to study the influence of the main parameters of the aerosol and the acoustic field involved in the process will be carried out along the second semester of 2014.

The main aim of the project is the intensification of drying processes at low temperature by using power ultrasounds which will be undertaken under three aspects. The first consists in the design of efficient ultrasonic generating systems and associated drying chamber, considering the interaction between the chamber and the produced acoustic field. The second aspect addresses the study of the influence of pretreatments of the raw matter on its structure and the effect of such pretreatments on the subsequent drying operation and power ultrasound efficiency. The third aspect addresses the drying process itself at low temperature and its interaction with other process variables. Finally, the effects of all process variables on the final product quality and energy efficiency will be investigated and quantified. Each mentioned aspect will be undertaken preferably by one of the participating teams (subproject).