Control valve, in particular for controlling and regulating steam turbines

摘要

Control valve, in particular for controlling and regulating steam turbines, with a valve element (3) displaceable in a valve guide (7) in the valve housing (1), a valve seat (4) arranged in the valve housing (1), and a diffuser (5) arranged downstream of the valve seat (4). Mounted on the valve guide (7) is a swirl-generating device which surrounds the annular opening formed between the valve element (3) and the valve seat (4) and the free cross-section of flow of which is larger than the narrowest cross-section (f) between the valve seat (4) and the diffuser (5). The swirl-generating device is preferably formed by a guide vane ring, the guide vanes (91) of which are set in a circumferential direction. The swirl-generating device produces a vortex (D), the centrifugal effect of which prevents separation of the flow (S) from the diffuser wall. By means of this stabilisation of the steam flow (S), the alternating forces which excite the valve element (3) to vibration are minimised. <IMAGE>