DRAINAGE OF WATER IN HEADRACE OF HYDRAULIC MACHINERY

PURPOSE:To prevent a drainage pump from being damaged on drainage by allowing water to be discharged detouring the drainage pump, during the time until the water level in a hydraulic iron pipe reaches rhe water level in a drainageway after the water level in the hydraulic iron pipe lowers to the water level in a lower pond. CONSTITUTION:After the water level in a hydraulic iron pipe 4 reaches the water level in a lower pond, a lower pond gate 9 is closed, and a headrace water discharging valve 13 is closed, and a bypass valve 18 is opened, then the water in the hydraulic iron pipe flows into a discharge channel 5 through a drainage pipe 12 made of steel and further discharged into a drainageway 17 from the discharge channel 5 through a drainage pipe 14 and a bypass pipe 19. After the water level in the hydraulic iron pipe 4 reaches the water level in the drainageway 17, the bypass valve 18 is closed, and the headrace water discharging valve 13 is opened, and a drainage pump 15 is driven, then the water felt in the headrace 5 is perfectly discharged into the drainageway 17, and drainage of water in the headrace is completed.