JPS57168100A - Cavitation erosion resistant device for pump - Google Patents

Abstract

PURPOSE:To loosen a shock pressure of cavitation and prevent erosion-corrosion by providing multiple nozzles on the inner circumference of the suction passage directly in front of a pump impeller eye and spouting steam toward the impeller inlet where cavitation is occurring. CONSTITUTION:Multiple steam nozzles 6 (6a-6d) are provided on the inner circumference of a casing 4 directly in front of an eye section 2 of an impeller 1. Steam blasts 10 spouted from the nozzles 6 are turned into numerous steam bubbles 10a, and are flowed into the impeller passage where cavitation is occurring. Since the steam bubbles have thermal energy, they can survive unbroken as steam bubbles, unlike cavitation bubbles, even after arriving at the place 1c where the cavitation bubbles are broken. Therefore, the steam bubbles perform a function f a buffer material which drastically reduces a shock pressure generated when the impeller cavitation bubbles are broken, resulting in a remarkable reduction of erosion-corrosion of the impeller material.