| 摘要 |
A flat throttling gate for bulb-type turbines and the like which is installed in a draft tube of the turbine. The gate has a central cutout of arcuate configuration flanked by a pair of ramps which cam a pair of masks into respective chambers flanking the guide slot for the slide body. Actuating mechanisms, e.g. springs, bias the masks against the valve body. In the withdrawn position of the valve body, the throttling cutout boundary, the masks and the wall of the draft tube define a circular flow cross section. In the inserted position of the valve body, a narrow flow cross section is provided between the wall of the draft tube or a lining thereof and a boundary of the cutout. |
