Process and device for sifting, sorting, screening, filtering or sizing substances

Abstract

In an apparatus for sieving, grading, sifting, filtering or sorting dry solid substances or solid substances in liquids having a sieve surface provided in a sieve frame and an ultrasound transducer (10) which is associated with the sieve surface (18) and by which oscillations can be fed to the sieve surface, associated with the ultrasound transducer (10) is at least one resonator (14) which bears against the sieve surface (18) and which is tuned to the resonance of the ultrasound transducer and which can be caused to oscillate thereby, in particular with flexural oscillations. The resonator (14) which in an embodiment is disposed in the center of the sieve surface (18) is to be provided with resonance-transmitting elements (16) which project finger-like from the resonator on the sieve surface (18) and which project radially from same in the form of bar resonators.

Dependencies are inferred from the claim text.