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A Computer Simulation Of The Rotary Drum Brownstock Washer System Using The Monte Carlo Method Of Distribution Sampling, Jacqueline K. Pease

Masters Theses

A steady-state probabilistic model is chosen to simulate the brownstock washing system's uncertainty which arises from unpredictable process fluctuations and measurement noise. Distribution sampling is used to construct multiple mass balances of a washing system. Included in this model is a linear relationship describing the correlation between dilution and displacement which allows displacement ratio to be generated based on dilution factor. This is an improvement over a similar, earlier model which considers all variables to be independent. There is no statistical difference between the mean output of the simulation and the means of data sets collected at two different mills. …

Removal Of Eucalyptus Vessel Segments Using Centrifugal Cleaners, Amnuay Ponpued

Masters Theses

Two commercial feedforward centrifugal cleaners were used in the study of vessel segment removal from bleached eucalyptus pulp. The reduction of vessel elements yielded a reduction of vessel pick tendency and other problems caused by vessel elements which limit the use of eucalyptus pulp in paper stock furnishes. The operating conditions of the centrifugal cleaners were evaluated for their effect on separation efficiency. Pulp loss with rejects was reduced by multiple stage separation. The Vandercook Proof Press was used to compare the picking of cleaned, original pulp and two higher-vessel-content pulps. Regression analysis and ANOVA showed significant effects of feed …

A Laboratory Simulation Of A Rotary Vacuum Drum Brownstock Washer, Hugh E. Muller

Masters Theses

Mass balances can quantify the dilution and thickening of a liquor/fiber suspension on a brownstock washer. However, the complex displacement process necessitates an empirical approach. Given empirical data, washers can be optimized through use of efficiency factors with mass balances.

Because empirical data is difficult to obtain, a laboratory washing method was developed to empirically generate displacement efficiencies on pulp under mill washer conditions. Reproducible data generated by this method resulted in a displacement/dilution function as seen on mill washers. A laboratory simulation using mill samples, exclusive of problems for one vacuum drum, resulted in comparable efficiencies with less than …

Theoretical Thermodynamic Properties Of Low Temperature Fluids, Zul Azhar Zahid Jamal

Masters Theses

The thermodynamic functions for low temperature fluids are computed using parametric integral equations and perturbation theory. Parametric integral equation N is applied to a low temperature Lennard-Jones gas. It is found that there is no significant improvement over the better known parametric integral equation C. The two parameter integral equation T is applied to a low temperature square-well potential and is found to be unsatisfactory at reduced temperatures of T*= 1.4 and 1.6, but quite accurate at T* = 2.2. The equation T results for T* = 2.2 are used as the reference system in perturbation theory computations. Tables of …

Improving Maintenance Effectiveness, Stephen J. Thierry

Masters Theses

A methodology is advanced for measuring the productivity of industrial maintenance operations. A work sampling study and a production to maintenance interface survey are conducted to identify the current level of maintenance effectiveness at a food processing plant. Variables affecting maintenance effectiveness are postulated from site observations of the plant maintenance operation. A total of nine changes are proposed; three are implemented as part of this study and six remaining changes are proposed for the future. All recommendations are targeted at increasing the overall effectiveness of the maintenance operation under study.