Physicochemistry of non-immersion ultrasonic cleaning

This thesis focuses on the study and scaling of a disruptive technology called "non-immersion ultrasonic cleaning".

Conventional ultrasonic cleaning is based on the introduction of dirty components in a liquid bath, where high intensity ultrasound is applied to detach the particles. The need to immerse the component in a tank represents a differential drawback compared to other procedures such as brushing and pressurized water jets.

The study is based on the hypothesis that the same cleaning principles can be applied without the need to immerse the object. To this end, the concept of applying ultrasound through a capillary bridge supported between the ultrasound emitter (sonotrode) and the surface to be cleaned is proposed and demonstrated.

The capillary bridge is swept along the surface, resulting in a novel cleaning process. Hence the motivation and main objective of the work carried out: to study and understand the physicochemical phenomena involved during non-immersion ultrasonic cleaning. To this end, analytical models, laboratory-scale experimentation and scaling of the technology for cleaning solar concentrator components, where the degree of cleaning has a direct impact on energy production, have been combined.