Procedure and means for separating or purifying organic substances

Method for separating or purifying a substance from a molten mixture by crystallization, comprising

• introducing the molten mixture into an annular space defined by two substantially curvilinearly-shaped surfaces, one of said surfaces being cooled and at least said cooled surface being rotated in a given direction, whereby said molten mixture is cooled on said cooled surface as the same flows through said annular space, and material continuously crystallizes to form a deposit on said cooled, rotating surface,
• causing said crystallized deposit to be contacted by a source of heat in a region downstream from where the molten material is introduced, thus melting said deposit at said downstream region,
• removing at least part of said melted deposit from said annular space at said downstream region, thus obtaining said substance in purified form,
• conducting any remaining part of said melted deposit through said annular space away from said source of heat in a direction opposite said given direction, and
• removing molten non-crystallized material which contains impurities from said annular space in a region spaced from said downstream region.
• wherein said cooled surface rotates with respect to said other surface.

Method for separating or purifying a substance from a molten mixture by crystallization, comprising

• introducing the molten mixture into an annular space defined by two substantially curvilinearly-shaped surfaces, one of said surfaces being cooled and said cooled surface being rotated in a given direction, whereby said molten mixture is cooled on said cooled surface as the same flows through said annular space, and material continuously crystallizes to form a deposit on said cooled, rotating surface,
• causing said crystallized deposit to be contacted by a source of heat in a region downstream from where the molten material is introduced, thus melting said deposit at said downstream region,
• removing at least a part of said melted deposit from said annular space at said downstream region, thus obtaining said substance in purified form,
• conducting any remaining part of said melted deposit through said annular space away from said source of heat in a direction opposite said given direction, and
• removing molten non-crystallized material which contains impurities from said annular space in a region spaced from said downstream region and at a point upstream of said introduction point.

Apparatus for separating or purifying a substance by crystallization from a molten mixture, comprising

• a first curvilinearly-shaped surface being cooled,
• a second curvilinearly-shaped surface, at least said cooled surface adapted to rotate in a given direction,
• an annular space defined between said two surfaces,
• first means for introducing the molten mixture to be separated or purified into said annular space,
• second means for cooling said first surface whereby material continously crystallizes as a deposit upon said cooled surface,
• a source of heat for melting the crystallized deposit in a region downstream from said first means,
• third means for removing at least a portion of the melted deposit from said annular space at said downstream region, thus obtaining the substance in purified form,
• fourth means for directing any non-removed, melted deposit through said annular space away from said heat source in a direction opposite said given direction, and
• fifth means for removing molten non-crystallized material which contains impurities from within said annular space in a region spaced from said downstream region.