Method in the manufacture of chemomechanical pulps
Abstract
Abstract A METHOD OF PRODUCING HIGH YIELD PULP BY IMPREGNATING WOOD CHIPS OR OTHER LIGNOCELLULOSE CONTAINING MATERIAL WITH A SOLUTION SELECTED FROM THE GROUP CONSISTING OF ALKALINE HYDROXIDES AND ALKALINE CARBONATES, AT A TEMPERATURE BELOW 100*C. THE IMPREGNATED CHIPS ARE COOKED IN A DIGESTER IN AN ATMOSPHERE OF SATURATED STEAM AT A TEMPERATURE EXCEEDING 100*C. AND UNDER CORRESPONDING SUPERATMOSPHERIC PRESSURE, WHILE SIMULTANEOUSLY INTRODUCING SULFUR DIOXIDE INTO THE DIGESTER FOR A PERIOD OF TIME RANGING FROM 1-20 MINUTES AND IN SUFFICIENT QUANTITY TO REACT WITH THE BASE CONTAINED IN THE WOOD CHIPS TO FORM AN ALKALI SULFITE COMPOUND. THE THUS COOKED OR DIGESTED WOOD CHIPS ARE THEN DEFIBRATED UNDER SUBSTANTIALLY THE SAME PRESSURE AND TEMPERATURE CONDITIONS PREVAILING IN THE COOKER. THE PREFERRED IMPREGNATION TEMPERATURE IS FROM 30-40*C. AND THE PREFERRED COOKING TEMPERATURE IS FROM 160-180*C.
Inventors
- 👤 Arne Johan Arthur Asplund
- 👤 Karl Nicolaus Cederquist
Bibliographic Details
Claims Analysis
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