Patent ID: 8453845

Claim:
A screen system with a tube-shaped screen, said screen system further comprising: (a) a tube having at least one section with a plurality of screen openings, which are placed directly in the wall of said tube, and that forms a screen frame which defines at least the length and the cross section of said tube, and a screen mesh, that is tensioned on said screen frame, so that said screen frame forms at least a part of the wall of said tube-shaped screen; (b) at least one ultrasonic converter; and (c) at least one feed-line sound conductor placed between said at least one ultrasonic converter and said tube, with said tube being configured as to be able by means of said ultrasonic converter and said at least one feed-line sound conductor to be subjected to ultrasonic excitation so that the amplitude of the ultrasonic excitation transferred to said tube has a component in a direction perpendicular to a central axis of said tube-shaped screen and a component in a direction parallel to said central axis of said tube-shaped screen.