Abstract: A method is described for the continuous disintegration of microbial sludge in a sewage clarification or sewage treatment plant wherein the microbial sludge is decomposed biologically by bacteria and the resultant sludge (5) is exposed to sonic radiation in a treatment vessel (1) in order to split the cell walls of the microorganisms. With that, the sonic radiation shall be generated asymmetrically in the treatment vessel (1). The intensity of the sonic exposure lies-in an area of 500 to 1500 W/m2 and the sludge (5) is fed with a mean dwell-time of 2 to 4 minutes in counter-flow through the treatment vessel (1). The device for carrying out the method possesses a treatment vessel (1) with an eccentrically arranged sonic resonator arranged within (7).

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.

Abstract: A method of producing and radiating ultrasonic energy in fluids, in particular for irradiating cleaning baths, having an ultrasonic generator and a converter or transducer associated therewith, is improved with respect of its mode to operation and efficiency by a resonator being immersed in the fluid and the fluid being irradiated by radial components which are produced in the expansion nodes of longitudinal waves of the resonator. A corresponding apparatus with an ultrasonic generator, in accordance with the invention, has a resonator (1) which is connected to a sound transducer (9) towards the fluid or the bath (7) and which is tuned in its longitudinal axis (M) to an integral multiple of the acoustic operating half-wave length.lambda./2, to produce transverse compressions at the expansion nodes thereof. The resonator (1) is preferably in the form of a hollow profile of round cross-section and may possibly also contain further resonators.