Date of Award

4-1983

Degree Name

Bachelor of Science

Department

Paper Science and Engineering

Abstract

The objective of this project is to determine if paper machine freeness meters can be applied to belt filter presses, so as to control the dosage rate of the polymer addition. Currently polymer dosage rates are set for the high demand loads and therefore, more polymer is used than is needed at the low demand loads. With the cost and use of chemical polymers increasing, the application of a control means to regulate polymer dose as required, should provide substantial savings in conditioning costs.

This study wants to show that a specific resistance tester is sensitive enough to pick up changes in the conditioning rate with reproduceable measurements.The similarities between the specific resistance tester and a paper machine freeness meter, should show that the paper machine freeness meter could be used in an on-line application with similar results.

The results of the resistance testing shows that the specific resistance tester is sensitive at picking up changes in polymer loading. The graphs of the data shows the tester to have a useful value relationship from the unconditioned level to about 40 lbs. of polymer per ton of dry sludge. Generally, the 40 to 100 lbs of polymer per ton of dry sludge levels have a flat curve relationship which would not be useful in a control set up. A measurement in the 40 to 100 lb level could not show a significant difference between the two levels. An interpretation of these results shows that a paper machine freeness meter could be applied to a belt filter press with effective results, but only within a limited working range. The meter would not be effective at the higher polymer levels, without further testing of sludge at higher collection volumes.

Keywords: Sludge, drainage, freeness, belt press, conditioning

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