Crystallization system and process

A system for crystallization of a substance to be crystallized which is dissolved in a solvent, the system comprising a crystallization apparatus which is flowed through by a solution to be concentrated having the substance to be crystallized dissolved therein, and which is flowed through by a heating steam or a heating liquid, wherein the crystallization apparatus comprises:

• at least one flow passage conducting the solution to be concentrated,
• at least one flow passage conducting the heating steam or the heating liquid, and
• at least one flow passage conducting vaporous solvent,
• wherein a respective flow passage conducting the solution to be concentrated is at least partly separated from a respective flow passage conducting the heating steam or the heating liquid by a steam-impermeable and liquid-impermeable wall and wherein a respective flow passage conducting the solution to be concentrated is at least partly separated from a respective flow passage conducting the vaporous solvent by a membrane wall permeable to the vaporous solvent, but not to the liquid solvent, wherein the crystallization apparatus is configured such that the solution to be concentrated is boiled in the respective flow passage conducting the solution to be concentrated and vaporous solvent produced during the boiling moves through the membrane wall into the adjacent flow passage conducting the vaporous solvent, wherein the respective flow passage conducting the solution to be concentrated has a width of at least 3 mm, and a sediment collection tank is arranged at a lower side of the respective flow passage conducting the solution to be concentrated at the bottom so as to collect crystals produced in the crystallization apparatus.