Freeze concentration has been practiced for centuries. In its earliest form it was as simple as leaving a barrel of liquid outside in the cold winter night. Water would crystallize and grow as a thick layer of ice along the inside walls of the barrel. The next day they would simply cut a hole through the ice shell and drain the now concentrated product. The water (now ice) was simply discarded.
Modern freeze concentration processes consist of a crystallization section where part of the water is converted into solid ice crystals using a refrigeration system. The ice crystals are then separated by filters, centrifuges or using the Niro technology - wash columns. This patented technology is a specific form of suspension melt crystallization and has made freeze concentration economically feasible for a wide range of applications. See the following pages for a process description