Failure analysis of the impellers of a feed pump

被引：7

作者：

Prakash, OM ^{[1
]}

Pandey, RK ^{[1
]}

机构：

[1] INDIAN INST TECHNOL,DEPT APPL MECH,NEW DELHI 110016,INDIA

来源：

ENGINEERING FAILURE ANALYSIS | 1996年 / 3卷 / 01期

关键词：

failure analysis; impeller; centrifugal pump;

D O I：

10.1016/1350-6307(95)00029-1

中图分类号：

TH [机械、仪表工业];

学科分类号：

0802 ;

摘要：

An eight-stage feed pump in a urea-manufacturing plant started showing a high overall vibration level 3 years after commissioning. The level continued to remain high for about 2 years. One day the pump seized and had to be taken out of service. Visual examination and NDE showed that three pump impellers were broken and most of the impellers had one or more vanes with cracked trailing edges. Chemical examination of impeller material did not show any serious irregularity regarding its chemical composition. Metallographic examination confirmed that the impellers were not subjected to proper heat treatment. A scanning electron microscopic examination of the crack in the trailing edge revealed striations. It confirmed fatigue to be the mechanism of cracking. Severe pressure pulsations caused cyclic loading, which was mainly responsible for crack initiation and its initial propagation. Further propagation led to breakage of the impeller. Measures to reduce the pressure pulsations and improve the fatigue strength of the impellers were suggested.

引用

页码：45 / 52

页数：8