Adapted from Phase II: This research is founded on the discovery of electromagnetic radiation emanating from a pulp refiner as a result of electron transfer phenomena. An apparatus for controlling the refining process based on this discovery has been patented; the apparatus consists of (1) a bipolar antenna mounted adjacent to the frame of a refiner to detect the electromagnetic pulses and (2) electronic circuits to analyze the duration and energy of these pulses. A recently described improvement on the invention does not rely on electromagnetic radiation and includes, among other differences, the means to determine the sign of the measured voltages. The observed phenomenon is a result of the impact of fibers and fiber bundles (flocs) in the refiner. As the fibers are structurally modified by these impacts and as new surfaces and particles are created, the electrical double layer around the fibers and particles is temporarily disrupted. This disruption is the source of the observed phenomenon and is a direct measure of the number (n) and severity (s) of these impacts. A prevalent method of refiner control is through specific energy defined as horsepower days per ton, hpd/t. This control parameter is an approximate predictor of resultant pulp quality. Another specific energy relationship is e=nxs. Previous attempts to measure both n and s in terms of known parameters have failed. The recently described improvement has the advantage over previous attempts in that it measures n and s by distinct classes according to a unique characteristic of the observed signal and thus is a better predictor of pulp quality. The method proposed is continuous and nonintrusive. The electronics are simple and easily maintained in the mill environment. It would permit greatly improved control, leading to significant improvements in energy conservation, product quality, and productivity, all of which will enhance the competitiveness of the paper industry. Phase i of the project is constructing the newly disclosed circuits and demonstrating their effectiveness in both the laboratory and the pilot plant. Initial studies of the correlation between the observed signal and current methods for characterizing refined pulps are being made.
