Impact of plate types on refining and specific energy consumption

Abstract

Fibre refining is one of the most important stages of mechanical and chemical fibre treatment with direct impact on the quality of the final product-paper. The raw material to be refined and the requirements regarding the final product quality determine the way and technology of refining (concentration, pH, pressure in the refiners, ratio of refining), arrangements of plates, rotor rotation number and micro frequency between the grooves and plates. In addition to these factors, influencing paper quality, the cost of fibre refining, i.e. specific energy consumption, is of equal importance. This research was developed in two directions: examination of the refining quality and specific energy consumption during refining. The plates made at the Faculty of Technology and Metallurgy in accordance with our own technology were cast in molds made of coated sand (sand coated with resin). These molds were zirconium coated before casting. Zirconium from the coat microalloys the molded material, thus essentially affecting the structure as well as hardness which, on the other band, influences the teeth sharpness after grinding. This affects the life of the refiner plates as well as the refining quality of pulp. The molds made of coated sand give refiner plates with smooth and flat surfaces, influencing the pulp flow and reducing the resistance of the pulp flow through the interteeth space of the refiner plates.