EVALUATING FURNISH BEHAVIOR

摘要

2114209 9306481 PCTABS00021 A drainage tester evaluates the reaction pattern of one or more reactions in a paper pulp furnish to predict behavior of the pulp on a paper line. The tester includes a mixing container in which an additive is mixed with the slurry under conditions that prolong the reactions in the container such that they take longer than the same reactions on a paper line. The mixer can also mimic the kinetic conditions (such as mixing by turbulence or passive diffusion) under which the additive is mixed with the furnish on the paper line. A test container has a screen bottom that separates furnish solid from slurry water by developing a pressure differential across the screen. An intermediate container is positioned between the mixing container and test container to provide a constant hydrostatic head on furnish transferred to the test container. A sensor above the screen in the test container monitors changes in the optical characteristics of a sheet formed on the screen to automatically determine the drainage time of the formed sheet. Sequential equal volume aliquots of furnish are withdrawn from the mixing container and sent to the test container at preselected time intervals after chemical additives are mixed with the furnish in the mixing container. Physical characteristics of the sheet, such as fines retention, drainage time and visual appearance, are recorded as a function of time from addition of additive to the mixing container. Behavior of the sheet on the paper line can be predicted in this manner to help an operator efficiently operate a paper machine system.