Shutoff element for gaseous media with a device for damping self-excited acoustical vibrations in cavities

Claim 1

In a shutoff element for a throughflowing gaseous medium containing means for damping self-excited acoustical vibrations which arise by virtue of the fact that a flow channel for the gaseous medium contains a cavity where there are located am impact zone and a dam-up point for part of the throughflowing gaseous medium, the improvement wherein said damping means comprises: said flow channel having boundary walls; channel means provided at least at one of the boundary walls of the flow channel; means for defining a space in which, during operation of the shutoff element, there prevails a higher pressure than in the flow channel; said channel means flow communicating said space with said flow channel for delivering from the space to the cavity a flow medium for damping the acoustical vibrations; said channel means being arranged such that the damping flow medium, delivered from the space to the cavity, is infed substantially to the region of the impact zone of the gaseous medium from a boundary of the cavity; a valve housing having a bore; said flow channel being constructed as a diffusor; said space which is at higher pressure being bounded by a substantially ring-shaped groove provided at a diffusor body in said bore of said valve housing; an outlet channel; a ring-shaped slot means for flow communicating said space with said outlet channel so that part of the through-flowing gaseous medium recirculates as the damping flow medium; a rapid closure valve containing a hub; a means for guiding a spindle on which said rapid closure valve with its hub is mounted in said flow channel, said spindle guiding means having its upper edge constituting the dam-up point in the impact zone; and said channel means being structured as damping bores for flow communicating the space with the flow channel and being arranged such that the damping flow medium impinges flow downstream of the dam-up point at the impact zone.