Flow dynamics of pulp fiber suspensions

Abstract

The transport between different equipment and unit operations plays an important role in pulp and paper mills because fiber suspensions differ from all other solid-liquid systems, due to the complex interactions between the different pulp and paper components. Poor understanding of the suspensions’ flow dynamics means the industrial equipment design is usually conservative and frequently oversized, thus contributing to excessive energy consumption in the plants. Our study aim was to obtain additional knowledge about the dynamic behavior of industrial pulp suspensions in order to evaluate the relative importance of the factors that influence pressure drop. To obtain mathematical correlations to quantify pressure drop for the transport of pulp suspensions, we studied four different industrial pulp suspensions (recycled pulp, eucalypt bleached kraft pulp, pine unbleached kraft pulp, and eucalypt [90%] + pine [10%] bleached kraft pulp) in a pilot rig specially designed and built for the effect. Application: Clear understanding of pulp flow dynamics will be useful for optimum design and operation of the conveying systems in pulp and paper plants.