Menetelmä ja laite monivaiheisessa tislauskoneessa

The invention relates to a method and a device for ensuring the sterility of distillate in a multi-stage distilling machine. All feed water of the multi-stage distilling machine is caused to flow through a first column (11) operating at the highest temperature so that the temperature of the feed water is at least 121 DEG C, 131 DEG C, 141 DEG C, respectively, and the delay time thereof is at least 8 min, 0.8 min, 0.08 min, respectively, so that the distillate of every column of the multi-stage distilling machine is sterile, including that of the last column operating at the lowest temperature. The feed water flows through a first flow line (13a) from a second column (12) to the first column (11), from the first column (11) through a second flow line (13b) to a separate heat exchanger (17) and returns through a third flow line (13c) to the first column (11).