Abstract: Method and apparatus for continuously concentrating liquids in a plurality of stages, the apparatus having an enclosure vented to atmosphere and enclosing a like plurality of overhead spaced sets or rows of nozzles and a plurality of troughs, one for and underlying each nozzle set. In each stage, liquid of one concentration is pumped to one nozzle set and partially evaporated by being sprayed from the set, with immediately prior or concurrent heating, as a flat, fan-shaped spray for fall into the underlying trough as a liquid of higher concentration, which, depending on its concentration, is either the starting liquid of the next stage or the product concentrate, the evaporation for air-sensitive liquids being conducted in an environment inert to the liquid.