The method and arrangement is for adding treatment liquor to comminuted cellulose material, preferably wood chips, during the manufacture of chemical pulp in a continuous process. The process uses a down-flow vessel where chips are descending down the vessel in a plug-flow and where treated chips are continuously fed out at the bottom of the vessel. By arranging more than two parallel pipes offset from the center of the vessel a better distribution of treatment liquor is obtained. Any disturbance of the chip plug flow descending down the vessel is reduced to a minimum.