Hitachi Zosen Corporation manufactures Double Disc Refiners for mechanical pulping under license from Andritz-Sprout-Bauer and handles single refiners of this brand as a part of refining systems. This paper introduces outline of the Double Disc Refiner (DDR) together with its feeding systems, Twin Refiner and Single Disc Refiner (SDR).
On the other hand, Hitachi Zosen Tomioka Machinery Co., Led. manufactures DDR and conical refiners mainly for stock preparation under license from Sulzer Escher Wyss GmbH of Germany. Second half of this paper presents their outlines followed by a literature on effective use of the refining energy written by Dr. Siewert and Mr. Selder of Sulzer Escher Wyss.