Distillation throughput from 30 to 250 L/hour. Vacuum evaporators with internal scraper, designed to work as single of multiple effect in series. To be applied whenever alternative source energy are available. It can be powered with hot water, steam, diathermic oil. Ideal to recycle any waste heat and to be combined with alternative source boilers. Specially configured to treat encrusting water-based solutions, it is equipped with an internal strong scraper to remove fouling and to concentrate up to crystallization fouling wastewater, saline water and high density waters. To be installed wherever a strong concentration is required.