Method and device for producing polyamides, with optimized flow management

A process for producing polyamides with optimized flow guidance, the process comprising:

• polymerizing lactam to a polyamide-containing polymer melt;
• granulating the polyamide-containing polymer melt to PA granules using granulation liquid;
• extracting monomeric and oligomeric constituents from the PA granules in an extraction column, wherein the PA granules are guided countercurrently to an extraction liquid stream;
• and
• feeding at least a portion of the granulation liquid into the extraction liquid stream at at least one infeed point of the extraction column to adjust a temperature and a lactam concentration of the extraction liquid stream, wherein the at least one infeed point comprises ten infeed points at most, wherein if the at least one infeed point comprises more than one infeed point the infeed points are disposed at different heights of the extraction column.

A device for producing polyamides with optimized flow guidance, the device comprising:

• a polymerization system;
• a granulation system;
• and
• an extraction column that comprises an inlet suitable for PA granules disposed at a top of the extraction column, an outlet suitable for the PA granules disposed at a bottom of the extraction column, an inlet suitable for an extraction liquid disposed at the bottom of the extraction column, an outlet suitable for the extraction liquid disposed at the top of the extraction column, and at least one infeed point suitable for a granulation liquid, wherein the at least one infeed point comprises ten infeed points at most, wherein if the at least one infeed point comprises more than one infeed point the infeed points are disposed at different heights of the extraction column,
• wherein the granulation system and the at least one infeed point are connected via a line through which a portion of the granulation liquid used in the granulation system is transferable to the at least one infeed point.