Modern drum pulping technology for recycled fibers

When investing in recycled paper production, one of the key decisions is to go for a vertical pulper station or a drum pulper. The known benefits of drum pulpers are gentle slushing making cleaner pulper accept with less stickies, low specific energy consumption and easier  maintenance with reduced cost. The realization of the drum pulper benefits require more capital for investment, but the lower lifetime costs will make positive payoff. Model Group investing in Sachsen OCC-production, selected Valmet Drum Pulper technology, two 32m drum pulpers located in existing building, for 2000tpd capacity.

Valmet OSR Drum Pulper technology is based on three major principles, that differ from the other similar solutions in the market. First, the lifter design and how it can be manufactured, creates more open area and volume for slushing and screening. Second, screening is devided in two stages, creating fine and coarse accepts. Third, early removal of dissolved fibres, enhances screening section to continue slushing of disintegrated material.

Two stage screening and two pulp fractions open further possibilities for OCC-line. Fine fraction is cleaner than usual pulper accept, and it makes potential to simplify OCC-line, like bypassing the coarse screening. Coarse fraction needs full treatment, but it assures also high material efficiency and low fibre loss. Combining innovations in slushing and potential of screening, drum pulper can be made shorter than traditional drum pulper types.  

Two drum pulpers give flexibility for production. Instead of one big drum pulper, each drum can be adjusted according to demand. Drums can run different raw materials, and drum own control parameters optimized for the raw material properties. At lower pulp demand, another drum can be stopped to optimize the energy use by utilizing full efficiency of the one.