A rotary feed includes a static part that remains stationary relative to a stationary reference frame and a rotating part that rotates with a rotor. The static part and rotating part run adjacent to each other and define a sealed flow channel for a first medium. A buffer chamber surrounds the static and rotating parts, and the transition between these parts. During operation, a barrier medium charges it at a transition between the static and rotating parts. An outlet connects the buffer chamber to a treatment head to permit a medium in the buffer to be fed to the nozzle for container treatment.
