Highest reliability, security and lower costs
One of the first priorities in the period from 2003 to 2005 was to upgrade the older Damatic Classic systems on PM 10 and the groundwood mill to modern metsoACN processing technology in the PCS process control stations and OPS operator process stations. The reliable field I/O was kept in place. Although the old systems were reliable enough, spare parts were running out as the technology approached the end of its lifecycle. The return on investment was based on improving system uptime by 10 hours/yr and reducing engineering change costs by 20%. With the new system technology engineering changes can be made while the process is running rather than off-line changes with the older system. Faster startups on PM 10 were projected with the new higher speed and higher resolution control capability. New stock blending controls were implemented, and those objectives were achieved. All in all, the goals of the system upgrade project were fully met according to Schober.
To extend the lifecycle of the processing hardware, the Metso Damatic XDi system on PM 10 is also being upgraded to the latest metsoACN RT stations. (PM 10's automation was partly Damatic Classic and partly Damatic XDi.) The upgrade program, which has been done step by step since 2004, was about 90% complete by the end of 2010. Serial links are being removed and replaced by modern Profibus connections to the motor control center and frequency converters.
Network infrastructure security became a serious problem in 2007 with a virus attack and, in 2008, two mill shutdowns were caused by compromised security. This critical threat to mill production was put to rest by replacing network components and installing a new centralized place for the server in 2010. To ensure continuous process level security Metso commissioned its DMZ super safe firewall which isolates the critical process control system from engineering level computers and external computers such as desktops.
To consolidate the control structure and save service costs, former PLC functions in the woodyard have been replaced by new Metso processing hardware. The PLC's, which controlled water cannon sprays, were becoming costly to service and hard to keep alive according to Mr. Schober. "It was like a black box with no visualization, and therefore hard to repair," he says. He reports lower maintenance costs with the new Metso process stations which are part of the wastewater treatment system which reports environmental compliance statistics.
In another cost saving investment, a new metsoACN C20 process station in the center of the wastewater clarifier is connected wirelessly to the system. This arrangement saved a lot of expensive cabling and signal transmission costs. Pump motor frequency converters are connected by Profibus.
Critical process data are available every two seconds to a variety of desktop users
Upgraded measurements and controls
Process measurements and controls have been upgraded in recent years with positive results. For instance, Metso's IQ WebCD multi-variable control was added to PM 10 in a new metsoACN station, providing a 25% improvement in overall profile variation and better paper quality.
On PM 11, Metso's IQWetendMD multi-variable predictive controller was added to improve wet end stability and reduced grade change times. And the control achieved that goal conclusively, reducing grade change times by about 10 minutes and increasing quality production. "In 10 minutes a lot of paper is made on this huge machine," adds Schober.
In 2009, a kajaaniRM200 white water consistency transmitter was upgraded to kajaaniRM3 to improve white water control, to improve paper quality quickly after a web break and to achieve maintenance savings. In 2010, a kajaaniCORMEC5 furnish color sensor is being commissioned in the groundwood mill to improve furnish shade consistency.
The infrastructure upgrades and additions also included on-line condition monitoring which is used as a maintenance planning tool. In 2006, the existing Sensodec Advisor condition monitoring system was upgraded to a Sensodec 6S with more extensive and faster vibration analysis capabilities and a user-friendly user interface which is used by papermakers as well as maintenance staff. Roland Stadlhuber, mechanical engineer, reports the new system has become an everyday papermaking tool. "The results of the vibration analysis are now available in seconds so we can see changes in mechanical condition. Unplanned maintenance has been reduced," he states. The condition of PM 10 components can be seen by maintenance and papermaking staff on six client desktop PCs.
A new Sensodec 6S was added in 2009 to the multi-nip polymer roll calender in the PM 11 line, replacing an older vibration analysis system. With the fast analysis of the new system "hot spots" on the soft rolls are detected quickly thus avoiding sudden and dangerous roll cover damage, not to mention the high cost of roll cover replacement. Overall, the mill hopes to extend the lifetime of polymer covered rolls by 10%, thus providing a good saving in roll covering costs.
With the online field device and valve condition assessment and configuration tool the calibration factors and alarm limits of transmitters can be set from a desktop and the performance of valves can be checked remotely. Unnecessary valve movements may indicate developing problems and initiate a valid reason for maintenance actions
Checking field device, valve assets
The mill has recently installed a Field Device Manager filed device and valve condition assessment and configuration tool. The goal is to reduce maintenance and tuning costs. Right now 167 devices including 50% of the valves are now connected. Using HART protocol communication, the calibration factors and alarm limits of transmitters can be set from a desktop and the performance of valves can be checked remotely. Schober says the asset management tool can be used to detect unnecessary valve movements which may indicate developing problems and initiate a valid reason for maintenance actions. He says the remote desktop access to the field transmitter has been very useful for ensuring the new kjaaaniCORMEC5 furnish color sensor readings are consistent with lab values. This avoids time-consuming field calibrations.
In a modern mill, fast and accessible process information is a vital lifeline for solving problems and improving process stability and product quality. Many problems can now be solved on a desktop, but the data acquisition rate must be fast enough to show typical short-term upsets and cyclical variations. In this respect the Laakirchen mill has upgraded its information acquisition and management capabilities with the 2007 installation of a new info server (No. 3) and Metso's DNAtracer data management application with 10,000 loop tags. Today, critical process data are available every two seconds to a variety of desktop users. "It is now much easier to follow the disturbances in the process so it is now used every day by our people to trace data and optimize the process. Maintenance people are using it as well," says Schober.
Productivity without interruption
The Laakirchen mill has now upgraded its control infrastructure to ensure an extended lifecycle, higher reliability and lower costs. By establishing this reliable control network, productivity without interruption is ensured. With improved platform processing power, additional control and diagnostics applications have been added. In addition, Schober emphasizes the improved visibility into the process performance, process controls and maintenance diagnostics. This openness is characteristic of a modern process automation network. "We have more insight and the network is much more integrated," he concludes.