The Application Of Ultrasonic Technology To Improve The Reliability Of Magnetic-Drive Centrifugal Pumps

Abstract

It is widely acknowledged that sealless magnetic drive pumps give total containment of the pumped process liquid, which in an industry where there are ever tightening environmental constraints on plant operation and increasing health and safety requirements, offers a real advantage of reliability and safety to users. However, as with any piece of process machinery, magnetic drive pumps are designed to operate within specific parameters and operation outside of these parameters can lead to reduced levels of reliability. Whilst traditional instrumentation (measurement of temperature or power) will assist in improving the reliability of the machine, these instruments are not monitoring the primary cause of the issue; instead they are monitoring the effect that the fault condition has on another part of the machine. By constantly monitoring the condition of the pumped liquid present in the internal flow regime of a magnetic-drive pump, it is possible to rapidly identify potential issues and react to them accordingly. Ultrasonic technology has been utilised to rapidly and accurately detect the presence of vapour in the liquid stream. The technology provides a precise and sensitive response to even the smallest change in phase, therefore improving the overall reliability of the machine. This paper presents an overview of the ultrasonic technology that has been utilised to monitor the condition of magnetic-drive centrifugal pumps, including highlights of extensive testing that has been carried out and some real world examples involving the application of this technology on volatile light hydrocarbon processes.