FIBROUS-WOOD PULP PH VALUE CONTROL APPARATUS Russian patent published in 1995 - IPC

FIELD: wood-working industry. SUBSTANCE: apparatus has electrode system with first electrode 1 and second electrode 3 formed as metal plates with different electrode potential, and carcass formed as hermetically sealed chamber. Electrodes 1 and 2 are embedded in chamber base so that their working surfaces are protruded. Thermal compensation system 5 has compensating electrode 11, first comparison unit 12, second comparison unit 13 and track unit 14. When electrode system is positioned in fibrous-wood pulp flow, electromotive force is developed between electrodes 1 and 2 as well as between electrodes 2 and 11, which is functionally dependent on medium pH value and temperature. First comparison unit 12 determines difference between potentials U1 and U2 of electrodes 1 and 2 and second comparison unit 13 determined the difference between potentials of electrode 2 and 11 to avoid influence of temperature on pH measurement result. The value of difference between potentials of electrodes 2 and 11 is extracted in track unit 14. Pulp flow running about electrodes 1, 2 and 11 provides removal of gas-and-oxide film by fibers present in this flow without adherence of fibre particles to electrode surfaces. EFFECT: increased quality of pulp by high-precision control of pH value and enhanced reliability in operation. 3 cl, 3 dwg