Metso's condition monitoring in the pulp mill

PLCs, DCSs & Controllers

Controller (standalone) suppliers

Distributed Control System suppliers

Programmable Logic Controller suppliers

printer friendly version

May 2012 PLCs, DCSs & Controllers

Erkki Jaatinen, Metso

The capabilities of an on-line condition monitoring system have been embedded in a DCS which uses common I/O hardware, signal processing hardware and software, engineering configuration tools and information trending and alarming. Machine operators and maintenance staff are now able to see developing vibration and process pulsation problems and determine their causes from a unified user interface combined with process control functions of the DCS. With this facility, operators are alerted quickly to developing problems allowing effective corrective action to be initiated. This operator-initiated maintenance combined with regular monitoring of machinery condition promotes a cooperative effort which improves machinery uptime and leads to cost-effective maintenance planning.

Abstract

Starting in the late 1980s, quality measurements and controls, machinery controls, drive controls, user interfaces and information management functions have been integrated and consolidated step-by-step in distributed control systems. Monitoring and diagnosis of field devices has also been added to the DCS capability. Today, modern DCS systems offer truly integrated operation and information analysis for all quality, machine and process control functions.

Machinery vibration and condition monitoring and analysis was the next logical step in this embedding process, and today that integration is a reality. Once the realm of maintenance specialists, the analyses of machinery condition, roll cover condition, process pulsations and many other diagnostic tools are now available to process operators as well as maintenance staff in an integrated DCS platform. The unified system uses common I/O hardware, signal processing hardware and software, engineering configuration tools, information trending and alarming, and user interfaces. A machine operator can now evaluate machinery condition alongside the usual process control and quality control functions in a single system. Maintenance staff can follow up the same information and utilise integrated diagnostic tools from the production floor or from the maintenance shop.

This integration comes at a time when maintenance and production departments in pulp and paper mills are developing programmes to coordinate their efforts in maintenance planning and predictive maintenance activities in order to ensure production goals are met and maintenance is focused on well-defined needs. The embedded condition analysis function in a DCS will therefore promote these cooperative maintenance and production planning programs and help mill staff to target maximum process availability and cost-effective operations.

The benefits of on-line condition monitoring are well known and documented. By analysing immediate and historical trends of machine vibrations, unexpected and costly failures and production outages are avoided. Thus, the mechanical assets of a mill are protected and workers’ safety is ensured. Condition-based maintenance planning is very effective at maintaining uptime at a lower cost since only the required maintenance is done at the most appropriate times.

To read the full Metso white paper including case study ‘Lime kiln roller misalignment’ visit http://instrumentation.co.za/+C16522

Share this article:

PLCs, DCSs & Controllers

Metso's condition monitoring in the pulp mill

Further reading:

Published by Technews