The washed-out starch slurry from the extraction unit will be pumped into the sixteen stage concentration and starch milk washing unit. The concentrated starch milk from the last stage will enter the washing unit. The final starch milk concentration is automatically controlled. The final starch milk is pumped to the filter trough of the rotary vacuum filter. The starch milk is diluted with water. The starch is sucked against the surface of the rotating drum and is scraped of by a fixed scraper device.