| 摘要 |
The invention relates to a multi-stage counter-current crystallization apparatus for crystallizing and subsequently separating a component in pure form from a solution, comprising a first concentration stage built up in part of: means for supplying the solution; first crystallization means, consisting of a heat exchanger of the scraped surface type for forming crystals in the solution; a first crystallization vessel for further growth of the crystals formed by the first crystallization means so as to obtain a first crystal suspension mixture containing larger crystals; first separating means for separating the larger crystals from the first crystal suspension mixture so as to obtain a first concentrated mother liquor solution; and at least one second concentration stage built up in part of: means for supplying the first concentrated mother liquor solution; second crystallization means consisting of a heat exchanger of the scraped surface type for forming crystals in the first concentrated mother liquor solution; a second crystallization vessel for further growth of the crystals formed by the second crystallization means; and means for returning crystals from the second crystallization vessel to the first crystallization vessel, wherein the crystal-growing vessel of at least one concentration stage is provided with a bypass conduit arranged outside the crystal-growing vessel for circulating the crystal suspension mixture that is present in the crystal-growing vessel, and wherein filter means are present in the bypass conduit for extracting at least part of the mother liquor solution from the crystal suspension mixture.
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