Successful start-up of Expansion Södra Cell Värö 2.0

Valmet a key partner

Valmet’s delivery was a part of the investment project “Expansion SCV 2.0” to increase Södra Cell Värö’s production of softwood pulp from 717,000 tonnes to 780,000 tonnes per year. Valmet delivered the main machinery, basic engineering, and installation, for both the capacity increase project and the brown stock washing enhancement project. A cutter rebuild was also carried out by Valmet.

“The purpose of the sub-projects in Expansion SCV 2.0 was to eliminate bottlenecks and increase the mill’s accessibility. Parts of the projects have also involved measures to improve user-friendliness and availability, which has contributed to more even quality of the end product and also increased energy efficiency,” says Viktor Jägerström, Project Director at Södra Cell Värö.

Better brown stock washing reduces costs

To reduce washing losses and bleaching costs Södra Cell Värö wanted to make targeted enhancements to its brown stock washing on the fiberline. To accomplish this, Valmet supplied the main machinery such as a TwinRoll press, a screw conveyor, and a medium consistency pump. The start-up was originally planned for April 2021, but due to the Covid-19 pandemic, it was postponed to October of the same year.

Capacity increase timetable was advanced

In addition to Södra Cell Värö’s decision to postpone the brown stock project, they also investigated the possibility of an earlier start for the capacity increase project, six months ahead of the originally planned date of April 2022. The reason was that it made more sense to have a joint start-up of both projects, in October 2021.

Valmet’s scope included a TwinRoll press, a ScrewConveyor, a DeltaKnotter, and a DeltaCombi screen. The delivery date for the Valmet equipment was successfully advanced to meet the new timetable and the Värö mill was also able to advance their own ongoing sub-projects that aimed to remove bottlenecks in the fiber line. This resulted in a successful joint start-up, six months earlier than the original date planned for Expansion SCV 2.0.

“In both projects, the delivery scope such as main machinery, basic engineering, and installation has worked well and has been well suited for the specific projects,” explains Jägerström.

New speed records after cutter rebuild

When the production capacity increased, due to the enhancements made in the fiber line, another bottleneck developed downstream in the pulp drying line. To be able to utilize the increased capacity all the way through the production line, the pulp cutter needed to be rebuilt. Cutter hydraulic system and related controls were rebuilt to get faster set-changes, which helped increase the speed of the pulp drying line and get the new production capacity out to the market. The rebuild was successfully performed and, since then, two world records for a softwood pulp machine have been reached. “The latest speed record was set on March 31 in 2022, with a top speed of 466 air-dried tonnes per day and width meter. The latest total running rate record was set on April 22, with a total running rate of 2608 air dried tonnes per day,” Jägerström explains.

Next step for an even brighter future

The overall strategic aim for Södra Cell is to use and refine its members’ wood raw materials, coming from the forests of southern Sweden. As the volume of these forest raw materials in southern Sweden are increasing each year, it is realistic for Södra Cell Värö to be considering a future long-term production capacity of 850,000 tonnes of pulp per year. But no decision has been made so far. “Although that is a logical next step, the necessary measures to get there are yet to be analyzed. Questions like if, when, and how remain to be decided,” Jägerström concludes.