Flash tank design

A water-steam circuit of a power plant comprising:

• at least one low-pressure steam system, and
• a vessel for waste water from the water-steam circuit,
• wherein the vessel has, in addition to at least one waste water inflow line, another heat supply from the water-steam circuit for evaporating an accumulating water fraction using energy from the water-steam circuit and a steam outlet that is connected, via a waste steam pipe, to the low-pressure steam system of the water-steam circuit and is adapted for introducing the entire steam mass flow into the low-pressure steam system of the power plant.

A method for purifying waste water of a power plant having a water-steam circuit, comprising:

• guiding the waste water into a vessel, and
• in addition to producing a steam fraction by automatic evaporation of waste water in the vessel, evaporating a water fraction that continues to accumulate using energy from the water-steam circuit and guiding the total steam mass flow into a low-pressure steam system of the power plant.