Developments in the design and construction of continuous full-scale ultrasonic devices for the EVOO industry

The road of scientific research from the pilot scale plant to the industrial applications is often long and winding. The introduction of an ultrasound device able to replace the malaxers into the virgin olive oil extraction plants is a matter deeply discussed. However, a full-scale industrial plant able to work in an effectively continuous mode is still lack in the market of olive oil extraction industrial plants. In order to overcome one of the main weaknesses of olive oil extraction plants, the discontinuity of the process due to the presence of the malaxer, a batch machine placed between the crusher and the decanter, effectively continuous ultrasonic full-scale solutions for the extra virgin olive oil industry have been developed. Practical applications: High power ultrasound for the treatment of olive paste represents a system to replace the malaxing phase, the weakest link of the chain in the VOO extraction process. The malaxer is a batch machine, which works between two continuous devices, the fruit crusher and the decanter. It is also a bad heat exchanger due to a not favorable ratio between the big volume of olive paste that should be warmed and the small surface for the heat exchange. New devices need to be developed in order to optimize the extraction plant, reducing the time of process, the resource consumption without compromise the oil quality, in order to guarantee a right profit for the olive millers. Shock waves and micro jets are produced when cavitation bubbles are collapsed. Cell layers of the fruit pericarp are destroyed by the cavitation effects.