Features Equipment & Systems
High Tech Paper Making on the Gateway to Lapland

The Veitsiluoto mill is an integrated production facility, processing approximately 2.6 million cubic metres of wood annually into pulp, paper and Nordic redwood products. The site’s integrated harbour has several weekly connections to the biggest European harbours all year round.

According to the Guinness’s record book, the Veitsiluoto mill is the world’s northernmost paper producer being only 120 km from the polar circle. Approximately one third of the pulp used by the mill comes from the northernmost pulp mill in the world. The pulp mill in Kemijrvi literally sits on the polar circle.

The Veitsiluoto complex employs some 1,500 people and it can ship out almost one million tonnes of paper products annually. Since 1996, the mill has been part of Stora Enso, the world’s largest paper and board producer.

Formula for success

So what is Veitsiluoto’s magic for survival and competitiveness?

History tells part of the story. In 1922, the mill location was found to be a good site for a sawmill. Plentiful, nearby raw material and access to Europe via the Gulf of Botnia helped the decision-making to start sawmill operations. Veitsiluoto Oy was incorporated and, soon after, pulp production started in 1930.

From the early days, management recognized the advantages of integration. This integration continued in 1955 when Veitsiluoto invested in the first paper machine. It didn’t take too many years before four modern machines were churning out newsprint, both for the smaller domestic market and the greater foreign market.

The new era started when production was shifting from newsprint to more value-added office papers and coated mechanical papers. Constant change has led to several equipment and paper machine rebuilds over the past 30 years. Converting capacity has been increased and today the mill truly is a fully integrated production facility. In other words, even sawdust is converted into paper sheet that is used with the printers every day.

Nothing is wasted.

Upgrades

Major changes did not stop in the machine room. Stora Enso totally restructured the maintenance operations. Maintenance resources of Stora’s northern Finnish and Swedish mills were unified and operate today as Fortek Oy. Fortek provides full service contracts to Stora’s pulp, paper and sawmills at Kemi, Kemijrvi, Pankakoski, Uimaharju and Oulu.

The Veitsiluoto mill, in Kemi, has been known to be a front-runner in implementing new maintenance concepts and technologies. In the early 1980s, the mill installed automated lubrication systems and condition-monitoring equipment to improve the overall equipment reliability in order to increase machine uptime.

The predictive maintenance group plays an important role in the planning of maintenance work.

PM3, built by Beloit, first started in 1963. It produced newsprint but was converted to fine paper in 1979. Before the latest major rebuild, the machine had been upgraded a couple of times in the 1980s and 1990s, e.g. a new top former, headbox and sym sizer were added.

Stora Enso’s Fine Paper Division’s decision to improve competitiveness in the growing office paper market led to the subsequent decision to modernize the PM3 production line. At the same time, the Kemijrvi pulp mill was to be integrated into Veitsiluoto paper production. This was required because the machine production was increased by more than 110,000 tons. Total investment of this uncoated fine paper machine rebuild was ?125 million and the project was completed in December 2003.

SKF was involved in the PM3 rebuild project from early on. All major OEMs including Andritz, Voith, Metso Paper and Honeywell supplied to the mill. Voith was in charge of the PM rebuild. The design speed of the machine was increased from 900 m/min to 1200 m/min resulting in major changes; for example the wet end was nearly replaced with new technology and the dry end had a major rebuild with only the original dryers remaining. There were several areas where the latest bearing technology was incorporated; for example the old rocker bearing housings on the dryer section were replaced with new housings CARB toroidal bearings from SKF. This solution greatly improves the construction stability by allowing for higher speeds. The design decreases the typical uneven bearing load caused by thermal expansion. Practically all bearings on the machine are SKF Explorer type, which have proven to give the longest bearing life.

The complete paper machine lubrication oil system was replaced. Voith’s delivery included three Vogel lube oil systems covering the wet end, dry end and the machine calender (Vogel AG is now part of the SKF Group). Three pumping skids equipped with the latest cleaning and purification equipment feed into the main pressure line. State-of-the-art gear type, volumetric oil flow metres measure and monitor oil flow to all bearings and gearboxes. In cases of a disturbance, an alarm is triggered and operators can then make informed decisions.

Oil flow data from the Vogel system, as well as an SKF on-line condition monitoring system is integrated into a monitoring system called “Machine Sentinel,” supplied by Honeywell. Machine Sentinel monitors paper machine runnability, paper quality and machine mechanical conditions. The SKF on-line vibration monitoring covers the whole machine, from stock approach to the reel. There are over 600 hard wired sensors connected to the system. The SKF system monitors the machine 24 hours a day. In case of a severe alarm maintenance, production people have detailed information available for decision making. The system helps to identify mechanical and operational problems, which then can be attended to in scheduled shut-downs. The system can be used for better maintenance planning, as well as for troubleshooting purposes. Together with lube oil monitoring, these solutions both prevent and predict potential failures in a harsh mill environment.

For less critical areas and equipment the Veitsiluoto mill is using SKF Microlog, SKF’s hand held equipment. SKF Microlog is an analyzer and data collector, that allows users to collect periodic condition monitoring data for computer-aided analysis. They can also be used for troubleshooting and balancing.

The Veitsiluoto mill is also involved in a project where several Stora Enso mills have a condition monitoring system on one server and the corporate wide area network (WAN) is used for data transfer. This SKF solution standardizes predictive maintenance concepts within the corporation. It simplifies IT issues and makes it easier for them to share experiences of predictive maintenance methods and troubleshooting ideas.

Kalevi Rantala, business unit manager of Fortek at Kemi, has a clear vision for the maintenance: “Increase the planned maintenance and to reduce and eliminate breakdown maintenance.” Rantala believes the Kemi mill has done a lot but “the bar is raised year after year.” Predictive maintenance improves planning by eliminating surprises. On the paper machine, this means better availability with lower maintenance costs.

As for the future, Rantala sees close cooperation between operational and maintenance staff as key to further reliability improvement. Close co-operation with equipment suppliers is also required. Preventive and predictive maintenance is Fortek’s core contribution in a partnership with suppliers. It helps guarantee the latest technology and reliability know-how. Together with end user’s application knowledge this will lead to best results.