NOVELTY - Flow-through ultrasonic reactor (1) for disintegration of flowable substrates, preferably biogenic sludges, preferably for increasing the yield during the production of biogas, or for treatment of preliminary, intermediate or finished products during the production of biodiesel or bioethanol, comprises at least one pipe section (2) for the passage of the substrate and for integration in a pipe system (11) for the substrate. At least one ultrasonic oscillator (4) is arranged outside the pipe section. The ultrasonic oscillator is designed for radiating ultrasonic energy into the substrate.    USE - The flow-through ultrasonic reactor is useful for disintegration of flowable substrates, preferably biogenic sludges for increasing the yield during the production of biogas, or for treatment of preliminary, intermediate or finished products during the production of biodiesel or bioethanol (claimed).    ADVANTAGE - The flow-through ultrasonic reactor: enables ultrasonic treatment of highly viscous biogenic substrates; increases the service life of the ultrasonic oscillator; and prevents the clogging of pipe sections.    DETAILED DESCRIPTION - Flow-through ultrasonic reactor (1) for disintegration of flowable substrates, preferably biogenic sludges, preferably for increasing the yield during the production of biogas, or for treatment of preliminary, intermediate or finished products during the production of biodiesel or bioethanol, comprises at least one pipe section (2) for the passage of the substrate and for integration in a pipe system (11) for the substrate. At least one ultrasonic oscillator (4) is arranged outside the pipe section. The ultrasonic oscillator is designed for radiating ultrasonic energy into the substrate through a wall of the pipe section during operation of the ultrasonic reactor for at least partially disintegrating the substrate or treating the substrate using ultrasound. INDEPENDENT CLAIMS are also included for:    (1) an ultrasonic treatment system (10) for disintegration of flowable substrates, preferably biogenic sludges, preferably for increasing the yield during the production of biogas, or for treatment of preliminary, intermediate or finished products during the production of biodiesel or bioethanol, comprising at least one flow ultrasonic reactor and at least one ultrasonic generator for operating at least one ultrasonic oscillator, where the pipe section of the flow-through ultrasound reactor is integrated in the pipe system for the substrate; and    (2) disintegrating flowable substrates, preferably biogenic sludges, preferably for increasing the yield during the production of biogas, or for treatment of preliminary, intermediate or finished products during the production of biodiesel or bioethanol, comprising conveying the substrate through at least one pipe section of the ultrasonic reactor, where the substrate is applied with the ultrasonic energy through the wall of the pipe section using at least one ultrasonic oscillator during operation of the ultrasonic reactor for at least partially disintegrating the substrate or treating the substrate by means of ultrasound.    DESCRIPTION OF DRAWING(S) - The figure shows a side view of flow-through ultrasonic reactor.    Ultrasonic reactor (1)    Pipe section (2)    Ultrasonic oscillator (4)    Ultrasonic treatment system (10)    Pipe system (11)