| 摘要 |
PURPOSE:To prevent the pressure reduction in the hydrauic line of the main oil pump. so as to permit continuous operation of a turbine by installing a mechanism for interrupting feeding of the working oil from a main oil pump when an emergency dump valve for rapidly closing a steam valve is operated on turbine emergency. CONSTITUTION:In the captioned apparatus, when an over-speed preventing relay 3 is energized on turbine emergency, and a spool is ulled up, the spool of an oil relay 4 is moved downward by a spring, which causes feeding of the working oil into the cylinder 18 of an emergency dump valve 5, to stop and the oil is discharged. Then, the spool 5a is pushed down by a spring 22, and the working oil in a hydraulic chamber h is discharged to lower a piston 17, and then a steam valve (not shown in the figure) is closed through the rod 11 of the piston 17. In this case, a cylinder 26 is install onto the upper part of the cylinder 18, in a body in order to feed the working oil f supplied from a main oil pump when the dump 5 is operated, and a feeding hole 24 is formed in the part on its side face to which the top edge of an oil passage g is brought into contact, and an oil discharge hole 25 is formed under said feeding hole 24. |
