Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering


In this study, two centrifugal cleaners -- the C-E Bauer Water-Master and the Beloit Uniflow -- were evaluated to determine the effects of entrained air in the stock on cleaning efficiency. A "neutral" density hot melt contaminant (specific gravity = 0.99) was added to dry lap pulp to simulate a recycled furnish. Various levels of a nonionic surfactant were used to induce foam in the stock; this foam was measured as percent air by volume. The cleaners were operated at a series of air levels and pressure drops, in order to generate characteristic curves. The results of the project indicate that, among the levels examined, addition of 1.4% air by volume generally increased cleaning efficiency; beyond this level, contaminant removal was adversely affected.

Recommendations for further research include exploring a wider range of pressure drops and smaller increments of air levels, and increasing consideration for the regulation of hot melt particle size.