The method of increasing of pulp yield with kraft cooking

The increasing of pulp yield in cooking process is very important for pulp-paper industry. The modified kraft cooking, such as polisulfide process, is one of the directions in increasing of pulp yield. We have developed and patented in Russia the method and the devise for its realization. This method is founded on influence of electric spark discharge, in form of high-frequency pulses, on white liquor or lixivium, which contains a wood-pulp material. Current pulse was generated by low inductance capacitor bank. Current amplitude has the order 30 kA, periode - 20 mks. The spark was initiated in liquor. The influence of single pulse or pulse series is also studied in this article. We have noticed variation of composition of liquor cooking in high-frequency pulse treatment. We have noticed in process of treatment an increasing of NaOH, decreasing of H/sub 2/S, variations in containing Na/sub 2/S/sub 2/O/sub 3/ and Na/sub 2/SO/sub 3/ with polisulfide generation. Cooking of several types of wood cheeps with solutions which treated of high-frequency current pulses, shows an increase of pulp yield in a range of 0, 9 - 2,7% (as to control).