Digestion of cellulosic material

Claim 1

IN THE CONTINOUS DIGESTION PROCESS OF TREATING LIGNOCELLULOSIC MATERIAL EXEMPLIFIED BY WOOD CHIPS, WHICH IS CHARACTERIZED BY IMPREGNATING THE CHIPS IN AN IMPREGNATING VESSEL, EVACUATING THE CHIPS THEREFROM AND DRAINING THEM OF EXCESS LIQUOR, MOVING THE CHIPS INTO A DIGESTION VESSEL FROM WHICH THEY ARE REMOVED FOR FURTHER PROCESSING, THE IMPROVEMENT WHICH CONSISTS OF THE STEPS OF SUBJECTING A CONTINUOUSLY MOVING COLUMN OF CHIPS TO STEAM AT SUPERATMOSPHERIC PRESSURE FOR NOT MORE THAN FIVE MINUTES, CAUSING THE STEAMED CHIPS TO PASS THROUGH A BATH OF WETTING LIQUOR, COOLER THAN SAID STREAM, SELECTED FROM THE GROUP CONSISTING OF WATER AND BLACK LIQUOR FOR A TIME SUFFICIENT TO SUBSTANTIALLY COMPLETELY SATURATE THE CHIPS WITH SAID WETTING LIQUOR, FOLLOWED BY CONTINUOUSLY PASSING THE COLUMN OF CHIPS THROUGH A BATH OF IMPREGNATING COOKING LIQUOR, STRONGER THAN SAID WETTING LIQUOR, FOR A TIME SUFFICIENT TO REPLACE THE WETTING LIQUOR WITH STRONGER IMPREGNATING LIQUOR, BEFORE THE CHIPS ARE DRAINED AND INTRODUCED INTO THE DIGESTION VESSEL.