Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering

First Advisor

Dr. Raja Aravamuthan


Clean pulp is essential to the optimum operation of any paper machine. The hydrocyclone is the most space, energy and cost efficient method to remove both heavy and light contaminants from a papermaking slurry. The efficiency of a hydrocyclone cleaner increases as the amount of removed contaminants increases. An efficient hydrocyclone allows the least amount of usable fiber to be lost in the cleaning process. Bradley devised a mathematical model to measure the efficiency of a hydrocyclone, and it is still the accepted model today. Several problems may exist with the Bradley Model as it applies to paper making slurries. A term for the consistency of the slurry is non-existent. This may or may not be an issue; but further examination is necessary. Ferguson has proposed a model, which does include a term related to consistency. This project evaluated the Bradley Model and Ferguson Model. The results showed that the Ferguson model better predicted the efficiency of the hydrocyclone at the consistency levels of 1%, 0.5%, and 0.25% and fiber lengths of 0.89mm and 1.17mm used in the projects. The Bradley Model was found to be reasonably accurate for longer fiber and higher consistencies. Viscosity of the suspension was found to be the major driver in both the value of the model parameters and the actual efficiency of the cleaner.