High-speed pump P3117B shaft broken
Thread Content
High-speed pump P3117B shaft broken. Time of occurrence: June 2002. Accident sequence: The current flowing through the pump suddenly decreased, pressure dropped, and after the pump stopped operating, there was severe leakage from the mechanical seal. Upon disassembly inspection, it was found that the high-speed shaft had broken behind the impeller, the impeller had fallen off, and the moving and stationary rings of the mechanical seal had separated. Cause analysis: This pump is a high-speed pump, with its high-speed shaft rotating at up to 8000 rpm. The process medium is an 13% ammonia solution; the inlet pressure is at atmospheric level, while the outlet pressure is 2.78 Mpa. If the process operation becomes unstable, vaporization can occur easily, leading to high-frequency vibration of the rotor, pressure fluctuations, and ultimately fatigue failure of the high-speed shaft, resulting in its breakage. Treatment result: Disassembly inspection, replacement of the high-speed shaft. Precautionary measures: Optimize operations and address vaporization of this pump promptly once it is detected.
Once the process operation becomes unstable, vaporization is likely to occur, leading to high-frequency vibration of the rotor, pressure fluctuations, and fatigue failure of the high-speed shaft, which may result in its breakage. Could the original poster explain in detail the reason for the high-frequency vibration of the rotor caused by vaporization, as well as the process involved?