Vacuum dewatering during paper manufacturing

Water removal during paper making is one of the most energy-intensive and capital-intensive processes. Vacuum dewatering is one of the intermediate stages of water removal on the paper machine where the compressible, wet mat is dewatered using applications of higher vacuum. A summary of the various stages of dewatering on the paper machine wire and the potential mechanisms of dewatering during each of the stage are given. Then, a review of the vacuum dewatering literature is presented detailing the empirical and theoretical work done to-date. A thorough description of the significance of airflow and associated convective mass transfer during vacuum dewatering is then described. A comprehensive approach to modeling vacuum dewatering considering most of the potential mechanisms involved is also presented.