Effect of Spiral Airflow for Water Purging

摘要

High performance spiral airflow apparatus of purging residual water in a pipeline has been developed. With this apparatus, the water in a 100 mm diameter pipeline including a U-shaped section and extending a Distance of 900 m was completely purged. The heart of the apparatus is a novel nozzle with an annular slit and A conical cylinder to create a spiral ariflow. In a U-shaped pipeline, the purging action depends, mainly, upon frictional drag by a purge air as a motive factor, and gravitational force as a retarding factor.