Patent ID: 8795468

Claim:
A method for the impregnation of chips during the manufacture of chemical pulp, comprising; continuously feeding chips without preceding steam treatment to a top of an impregnation vessel, feeding out impregnated chips from a bottom of the impregnation vessel, adding hot impregnation fluid (BL), at a first temperature above a boiling point of the hot impregnation fluid, to the impregnation vessel, via a pipe having an outlet end located below a chip level (CHLEV) established in the impregnation vessel and at a distance from walls of the impregnation vessel, the hot impregnation fluid (BL) releasing steam into a chip volume for steaming the chips, the added impregnation fluid (BL) establishing a fluid level (LIQLEV) in the impregnation vessel, the chip level (CHLEV) being above the fluid level and the top of the impregnation vessel having a pressure that is essentially at atmospheric pressure, withdrawing spent impregnation fluid (REC), at the fluid level (LIQLEV), from a withdrawal volume located behind screens mounted in a wall of the impregnation vessel, adding an additional fluid (REC 1 ) at a second temperature above the boiling point of the additional fluid into the withdrawal volume, the additional fluid releasing steam into the withdrawal volume, and leading the steam towards the chips below the chip level (CHLEV) for steaming the chips.