I always enjoy reading articles written by Emerson’s Jonas Berge. He explains concepts simply and makes them easily understandable. What prompted this thought is a recent article in Control Engineering Asia magazine, Value from Vibration. You may recall Jonas from numerous electronic device description language (EDDL)-related posts. Jonas contributes heavily to the educational efforts of this global IEC 61804-3 standard on the EDDL.ORG website.
In the article, he explains that most plants and mills already protect their large compressors, turbines, and rotating equipment with machinery protection systems. Due to the cost of this equipment as well as the installation costs, smaller production assets such as motors, pumps, fans, blowers, agitators, rollers, gearboxes, conveyors, crushers, rotating drums, and rotating kilns have not been instrumented with machinery monitoring systems. For this equipment, what’s typically done is a manual inspection process, performed monthly or quarterly with portable vibration monitoring equipment.
Jonas highlights the shortcomings of this approach:
Problems thereafter will go undetected until the next measurement several weeks later. If the equipment is not running at the time of check, no data can be collected for that round, and it has to wait until the next opportunity. Moreover, a vibration problem may only be noticeable at a particular speed and go undetected if the machine happens to be running at a different speed at the time of checking.
Jonas shares the technology advancements of compact, wireless vibration transmitters and the EDDL device communications standard as methods to now continuously monitor this plant equipment. How? By:
…using the international standard IEC 62591 (WirelessHart) protocol… these transmitters digitally integrate with the DCS and intelligent device management software making use of its visualization, alarm & event logging, historian, etc. No separate system is required.
Accelerometers, used to measure vibration, are now available with low power consumption models. A single wireless vibration transmitter can support two of these accelerometers or one accelerometer with embedded temperature. Jonas describes the benefit in moving from manual checking on a monthly/quarterly basis to continuous monitoring on a minute-by-minute basis:
This provides prompt notification when a problem begins to develop, as well as an indication of how quickly the problem is progressing toward failure.
The result of early warning of impending problems can be unplanned shutdown and costly repair avoidance. With the EDDL integration, the diagnostic alerts can be made available to the operators with guidance if the problem is process-related as with pump cavitation or equipment-related as with a bearing failure. Graphical views showing green, yellow, and red zones help simplify vibration diagnostics for plant operators and maintenance technicians.
Because this vibration information is available along with the pressure, temperature, level, flow, etc. process variables, all of the analytical tools in the DCS and asset management software allow correlations to be performed to help identify process performance issues resulting from equipment issues. The same tools used for trending, event analysis, audit trails, and graphics are available with the vibration diagnostics. This helps to make the information part of the existing work processes.
Much like advanced control migrating from separate applications into DCS controllers, wireless vibration transmitters built on the EDDL standard make the information readily accessible for action by the plant staff to help reduce equipment failure and unplanned downtime.
