Method for controlling an acoustic cell

• Main Authors: CUBETA, JEREMIE, SERGEANT, DAVID
• Format: Patent
• Language: English; French; German
• Published: 29.10.2014
• Subjects: FOR PERFORMING MECHANICAL WORK IN GENERAL; GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL; METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICALVIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY; PERFORMING OPERATIONS; TRANSPORTING

The present invention is related to an iterative method for controlling an acoustic cell (1) separating dispersed particles in a liquid medium, said acoustic cell (1) comprising two opposed plates (5) delimiting a resonating cavity filled with said liquid medium, at least one of the opposed surfaces (4) comprising a piezoelectric transducer (4) coupled to an electrical power generator for producing ultrasonic waves in said resonating cavity, said method comprising the steps of: a. applying an ultrasonic sound field by applying a periodic electrical potential of initial resonant frequency fi and initial power Pi to said piezoelectric transducer (5); b. measuring the cosine of the resulting phase shift phi (cos(phi)) between the electric current and the electric potential applied to the transducer (5); c. if the cos(phi) is lower than a predetermined threshold, increasing the power Pi, else decreasing the power Pi; d. determining the sign of the gradient of cos(phi) as a function of the frequency; e. varying the frequency in the gradient direction thereby maximising cos(phi); f. getting to step (b).