Voith introduces a new screen plate design for pulpers used in recovered paper pulping. The CurvedBar screen plate extends service life in Voith's IntensaPulper IP-R by more than 50 percent and improves the quality of fiber suspension. The results are less maintenance effort and material use, as well as fewer downtimes, leading to a more efficient overall process and lower costs. Chinese paper manufacturer Shanying International Holding Co. LTD., has tested the CurvedBar screen plate on its PM 5 in Maanshan and is now equipping other pulping systems with the innovative solution.
“With the new CurvedBar technology, we substantially reduced downtime and extended maintenance intervals at the pulper with consistently high operating quality,” says Wan Tao, Vice President Production at Shanying International Holding Co. LTD. “We also achieved very positive results from the coarse screening.”
To reduce the high mechanical loads on the screen plate, Voith developed an innovative curved bar design and optimally matched to the geometries of pulper, rotor and screen plate. “This results in a much longer service life compared to conventional screen plates,” explains Oliver Lüdtke, Global Service and Product Manager at Voith Paper. The lower friction also reduces energy consumption. “Combined with savings in material and maintenance, significant cost-saving potential can be realized, and the customer’s carbon footprint is reduced due to greater sustainability,” says Lüdtke.
Lower shearing forces, higher quality fiber suspension and problem-free ragger formation
Thanks to the lower shearing forces on the screen plate, far fewer contaminants are shredded. This improves the quality of the fiber suspension, reduces the amount of small rejects that need to be laboriously removed in the downstream process steps, and allows trouble-free ragger formation. Furthermore, the risk of bar breakage and deformation of the screen plate is significantly reduced. The CurvedBar screen plate has proven its effectiveness at Shanying in Maanshan, China, and other locations.
“With the new curved technology and premium W material, we optimized and reduced the flake content and are maintaining high-efficiency pulping performance in the long term,” says Song Jie, Manager of the Technical Department at Shanying International Holding Co. LTD. “The flake content is about 15 percent, the lifetime of high-efficiency pulping performance is extended from two months to five months.”