SES System Efficiency Service identifies pressure surges as the cause of damage
In the cooling water circulation process of a reactor, two successive major failures of pumps impaired the process flows. Pump measurement with high sample rates shed light on the cause.
In the cooling water circulation process of a reactor, two successive major failures of pumps impaired the process flows. Pump measurement with high sample rates shed light on the cause.
The challenge:
Detecting the cause of pump failures
For the cooling tasks involved in the chemical processes of a reactor, two mag-drive pumps are employed in the secondary circuit. In single-pump operation, they circulate water of over 200 °F between the reactor and several heat exchangers. To increase the fluid temperature more rapidly after a product change in the reactor, steam is fed into the cooling circuit. The entire system process has already been comprehensively measured and monitored by the process control system.
The solution:
SES System Efficiency Service identifies pressure surges as the cause
During plant operation, the mag-drive pumps failed repeatedly within a very short time. Both pumps showed signs of rubbing contact in the pump casing and destroyed plain bearings. These two damage symptoms indicate large forces acting on the pump rotor; such forces cannot result from normal pump operation after such a short operating time. The plant operator's process data displayed no signs of irregularities in the operation of the system.
It was only the comprehensive damage analysis at the pumps, using measurements with high sample rates in the potentially explosive atmosphere of zone 1, that revealed pressure surges. The speed at which the pressure surges propagate in the system is in the millisecond range and could not be detected by the existing process control system. Consequently, for technical reasons, this effect remained invisible to the operating personnel.
The result:
SES detects pressure surges in the millisecond range
KSB’s measurement revealed that the pressure surges only occurred at specific times when steam was fed in to increase the fluid temperature. With this information it was possible to define measures together with the plant operator to prevent pressure surges.
Broken bearing bush of the process pump
Comparison of customer measurement and pressure measurement with high sample rate performed by KSB (rate: 0.1 s)
Data | Facts | Figures
Application: Hot water process in the reactor
Year: 2017
Project data:
2 x mag-drive pump MAC 200-150-315 from KSB