Characterization of Sealing Ring Cavitation in Centrifugal Pumps with Water and Viscous Oil

摘要

This research paper presents characterization of sealing ring cavitation in centrifugal pumps with water and viscous oil. The paper discusses development of theoretical formulation for sealing ring cavitation and simulation using software model along with experimental validation. The pump performance test results and its standard clearance for the sealing ring are used to simulate the theoretical model. The study is extended for pumps with SAE-30 lubricating oil. The simulation results present the variation of downstream pressure with different sealing ring dimensions in pumps. The value of downstream pressure determines the possibility of occurrence of cavitation at the clearance. The theoretical formulation developed is validated by using a venturi cavitation test set up. Clearances equivalent to various sealing ring dimensions are made at the test section using different hemispherical models. Theoretical formulation for downstream pressure at the clearance of venturi test section is derived using the test set up details and pump specification. The clearance cavitation coefficients as per K. K. Shelneves equation are obtained from theory as well as from experimentation and compared. The phenomena of cavitation damages the sealing ring which results a fall in performance of the pump. However this research work lead to the prediction of sealing ring cavitation in centrifugal pumps handling water and oil enabling the replacement of sealing ring before affecting cavitation damage.