Stock preparation taken to new level with Valmet cleaning system

SK Wrexen Cleaners

Smurfit Kappa was looking for a replacement cleaner system for its Wrexen Paper & Board mill’s PM3 line. The mill's current cleaners had reached the end of their technical lifecycle, and due to age, had become difficult to maintain. At the same time, the company also realized that it could improve its energy efficiency and the cleaner’s performance. The result was a decision to invest in Valmet’s cleaner technology.

Smurfit Kappa Wrexen Paper & Board specializes in producing containerboard for the German and European market and bookbinding board that is distributed globally. The mill’s annual capacity is 320,000 tons.

The cleaner system renewal project was initiated by the need to replace the technically outdated cleaner at PM3. The investment, however, ended up having several other objectives as well.

“As a company, we are committed to delivering a better tomorrow, and seek to increase the sustainability of our operations at every corner. Energy efficiency very soon became one of the key targets of our cleaner investment, but we were also looking for a solution with controllable and efficient rejects separation and user-friendly maintenance”, says Kay Berndt, Operations Manager, Smurfit Kappa Wrexen.

Valmet’s solution: Hydrocyclone Cleanpac 700

Valmet is known for its solid expertise and understanding of production-specific stock preparation processes. The modern solutions are designed to reduce energy and water consumption, minimize raw material costs, and deliver excellent end-product quality.

“Prior to our proposal, we pieced together the customer’s needs and discussed the optimal solutions in-house with our technical experts. Our solution, Valmet Hydrocyclone Cleanpac 700, is especially suitable for cleaning recycled fibers and features a satellite system concept with a unique inlet head design for configuration flexibility. But most of all, it provides improvements in energy efficiency and rejects separation and easy maintenance for trouble-free performance”, says Fernando Huerta Blanquez, Product Sales Manager, Valmet.

CRC bottom dilution is installed in all cleaner stages in order to reach optimal fiber recovery and approved runnability.

Clear line lower cones are installed in the 1st and 2nd stages. Since the cones are made of transparent material it is easy to visually inspect the cleaner plant to identify if hydrocyclones are in need of maintenance.

Individual shut-off valves are installed in 3rd cleaner stage in order to make the operation even more flexible. The shut-off valves make it possible to shut off a cleaner during operation if maintenance is needed.

Energy-efficiency targets were reached

The number-one measurable target for the cleaner technology update was energy efficiency. Valmet Hydrocyclone Cleanpac 700 cleaners increased cleaning capacity while also removing one pump from the mill’s system. After the rebuild, the total calculated energy savings were as much as 800 MWh per year – mainly due to the flexible cascade that reduces the number of cleaners and the flow.

In regards to cleaning performance and reject separation, the new cleaner technology has also proved successful. Prior to the rebuild, the reject ash content was as low as 45% whereas with the new Cleanpac 700 it reaches 70%. This results in good fiber savings of approximately 2.5 tpd.

“Overall, we are very satisfied with Valmet’s solution, and also the project management and technical support were on outstanding level”, says Kay Berndt.
“Overall, we are very satisfied with Valmet’s solution, and also the project management and technical support were at an outstanding level.”
Kay Berndt, Operations Manager, Smurfit Kappa Wrexen