Operating Experience of High Speed Refiner

Abstract

Nippon Paper Industries Iwanuma Mill produces Refiner Groundwood Pulp(RGP)as mechanical pulp for High-quality newsprint, which is one of our company's strategic products. RGP process consumes much energy compared to DIP or KP process. The energy consumption of RGP is equivalent to１ ０％ of energy used in whole mill. The energy is supplied by mill's own boilers and turbines. Since one of the boilers is heavy oil boiler, recent steep rise of oil price made a serious impact on RGP production cost. Under these circumstances we introduced High-speed refiner made by Andritz K. K., for the first time in Japan to reduce primary refining energy consumption. This High-speed refiner had been already introduced to several TMP process (RTSTM) outside Japan and they are successful in saving energy. However, there was no precedent installation in Japan, no knowledge about resulting RGP properties were available. Therefore pilot scale trial at Andritz K. K. pilot plant was conducted. The result showed that saving energy while maintaining pulp properties were possible. According to these results we decided to introduce this refiner. The installed High-speed refiner is single disk refiner, which has distinctive rotational speed of２， １ ５ ０rpm. Specific energy was reduced from１， ２ ０ ０kWh／t to６ ８ ０kWh／t with same pulp properties.This report shows operation experience of High-speed refiner in saving energy of RGP process compared to former refiner.