Photo of a mag-drive pump in the secondary circuit of a reactor
3 min read

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 about 100 °C 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. 

Image of the broken bearing bush of the process pump

Broken bearing bush of the process pump

Graphic of a pressure measurement with high sample rate performed by KSB (rate: 0.1 s)

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

Used Services

SES System Efficiency Service

SES System Efficiency Service®

Increasing the economic efficiency of your pumping system through comprehensive system analysis

Pumps that are not optimally matched to the system consume too much energy. Thanks to SES System Efficiency Service® from KSB, this doesn’t have to be the case.

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