Continuous digestor

Claim 1

A CONTINUOUS CHEMICAL PULPING PROCESS WHICH COMPRISES TREATING WOOD CHIPS IN A RELATIVELY WEAK ALKALINE BLACK LIQUOR, DRAINING SAID BLACK LIQUOR FROM THE TREATED CHIPS, SATURATING THE TREATED CHIPS IN WHITE LIQUOR WHILE GRADUALLY INCREASING THE TEMPERATURE OF SAID WHITE LIQUOR, SUBJECTING THE TREATED CHIPS TO DIRECT CONTACT WITH STEAM TO RAISE THE CHIPS TO A COOKING TEMPERATURE, COOKING THE THUS TREATED MATERIAL UNDER CONDITIONS OF ELEVATED TEMPERATURE AND PRESSURE, DILUTING AND COOLING THE PULP STOCK THUS PRODUCED IN A FIRST WASHING STAGE WITH A FILTERED COOLING LIQUOR DERIVED FROM A SUCEEDING WASHING STAGE, DILUTING THE PULP STOCK AFTER THE FIRST WASHING STAGE WITH WHITE WATER IN SAID SUCCEEDING WASHING STAGE, FILTERING SAID PULP STOCK, AND PASSING THE FILTRATE THUS RECOVERED TO SAID FIRST WASHING STAGE TO DILUTE SAID PULP STOCK ENTERING SAID FIRST WASHING STAGE, OF CHIPS MOVING ESSENTIALLY DOWNSTREAM THROUGH SUCH SATURATING SAID SUBSEQUENT STEAM CONTACTING STEPS EXPOSED TO APERTURED CONDUIT MEANS, SUCH PROCESS ALSO INCLUDING THE STEPS OF FEEDING SUCH SATURATING LIQUOR TO THE CHIPS THROUGH THE UPSTREAM END OF SUCH CONDUIT MEANS AND FEEDING THE STEAM TO THE CHIPS THROUGH THE DOWNSTREAM END OF SUCH CONDUIT MEANS AND GENERALLY COUNTERCURRENT TO SUCH DOWNSTREAM CHIP MOVEMENT.