Meticulous planning, follow-up and consensus turned a challenging project into a resounding success, thanks to the hard work from the project team. Innovative customized solutions made it possible to dismantle the old filters and install a new wash press in the existing premises rapidly and smoothly.
Vallvik Mill is part of the Rottneros Group and is situated 150 km south of Sundsvall in Sweden. The mill is a world leader in ePulp, intended for use in electrical insulation materials, transformer boards and condenser paper. The mill is also a world-leading supplier of filter products for the automotive industry, made possible by the superior quality of Vallvik’s special pulp.
One of the bottlenecks at Vallvik was the pulp mill’s worn-out prescreening equipment. Upgrading the prescreening equipment is part of the Rottneros “Agenda 500” program to increase the mill’s capacity.
Valmet’s delivery included basic project design, removing the existing filters, installing our equipment and platforms, as well as inspections and commissioning.
The rebuilding work at Vallvik took place in two phases: the first phase was completed in fall 2016 and involved a conversion to a three-stage screening room.
In the second stage, a wash press replaced two older screening filters, making a capacity increase to 40 adt/h possible, and – more importantly – a reduction of COD discharges from the mill, thanks to much more efficient washing.
Valmet had to dismantle the old filters and install the new wash press in the existing premises. The solution was to remove the roof of the existing screening filter and install new roof sections that could be lifted off for the shutdown. All the lifts were carried out via the roof, using a mobile crane.
The next challenge was to find the ideal solution for the foundation to support the wash press. The final, clever metal construction has an adjustable side support that speeds up assembly and ensures that the wash press feet are in the right position.
All of this happened in less than five days!
One of the project’s greatest challenges has been to coordinate the work of a large number of firms working in a small space to tight deadlines. Good planning and hard work – from Valmet, Vallvik and other suppliers – made it possible to save an impressive 24 hours of assembly time, allowing more time for inspections and running the press with water. These processes went smoothly, and the press was ready for pulp on time.
The working relationship with the customer has been excellent throughout the project, with consensus reached about all potential uncertainties at an early stage. All the necessary information was sent and received in good time, and any problems that arose were addressed and solved together.