NOZZLE SEAL DEVICE FOR CROSS FLOW WATER TURBINE

摘要

PURPOSE:To prevent generation of cavitation erosion at operation for a long time and improve sealing effect of the terminal end part of a nozzle by forming a seal block which is fitted on the wall of a casing at the terminal end of the nozzle and seals the gap opposed to the outer circumference of a runner vane, out of anticorrosion rubber. CONSTITUTION:In a nozzle seal device, a seal block 4b is fitted on the wall of a casing 1 at the terminal end part of the nozzle 3 of a cross flow water turbine, and the gap opposed to the outer circumference of a runner vane 5 is sealed with it. In this case, the seal block 4b is formed out of anticorrosion rubber. The seal block 4b is fixed on the casing 1 at the terminal end of the nozzle 3 with bolts 9 through a washer 8. Consequently, when seal gap formed between the seal face 6 of the seal block 4b at the terminal end part of the nozzle 3 and the outer circumference of the runner vane 5 is made narrow for prevention of water leakage, even if flow speed of water passing through the nozzle 3 is increased and cavitation is generated, the seal block 4b is not eroded due to its corrosion resistance.