Separation tower and method for treating condensed water

A method for treating condensed water, comprising the following steps:

• 1) turning on a vacuum pump, injecting condensed water into a first-effect evaporation unit through a condensed water inlet, and introducing a heat source for heat exchange into the outside of a pipeline in a first heat exchange chamber, wherein the condensed water inlet is disposed at a bottom portion of the first-effect evaporation unit;
• 2) enabling the condensed water and the heat source to exchange heat in the first heat exchange chamber, dividing the condensed water into a first vapor phase and a first liquid phase, enabling the first vapor phase to enter a first vapor passage after the first vapor phase passes through a first demister and to enter a next effect evaporation unit through the first vapor passage, and enabling the first liquid phase to flow from a first downcomer to the next effect evaporation unit through a first loop-shaped apparatus to become a first concentrated liquid phase or to be spontaneously evaporated in the first loop-shaped apparatus;
• 3) enabling the first vapor phase to enter the outside of a pipeline in a second heat exchange chamber through the first vapor passage to exchange heat with the first concentrated liquid phase as a heat source for second heat exchange, after heat exchange, condensing the first vapor phase into a condensed liquid and enabling the condensed liquid to flow downwards from a first condensed liquid channel into a first U-shaped tube, performing second heat exchange on the first concentrated liquid to obtain a second vapor phase and a second liquid phase, enabling the second vapor phase to enter a second vapor passage upwards through a second demister and then enter the next effect evaporation unit or a final-effect condensation unit, and enabling the second liquid phase to enter a second apparatus through a second downcomer and flow to the next effect evaporation unit or to be spontaneously evaporated;
• and
• enabling the vapor phase to enter the final-effect condensation unit to be condensed and mixed with the condensed liquid to become pure water to be discharged, while discharging concentrated water left after multi-effect evaporation.