Method and device for the production of polyamide

A device for production of pellets of polyamide 6 or copolyamides, the device comprising:

• a. a polymerization reactor to polymerize polyamide 6 or copolyamides to form a melt;
• b. an underwater pelletizer, wherein the underwater pelletizer receives the melt from the polymerization reactor, and wherein the underwater pelletizer pelletizes pellets into a process fluid;
• c. an extraction device in fluid communication with the underwater pelletizer, wherein the extraction device receives the process fluid and pellets contained within the process fluid from the underwater pelletizer through a fluid removal connection, and wherein the extraction device is adapted to perform extraction of low-molecular components by using fluid based or water based extraction;
• and
• d. a dryer positioned downstream of the extraction device for drying the pellets, wherein the underwater pelletizer and the extraction device are operated with the same process fluid, and wherein there is a fluid return connection for the process fluid disposed between the extraction device and the underwater pelletizer;
• and
• wherein the process fluid is carried in a first circuit between the underwater pelletizer and the extraction device through the underwater pelletizer, the fluid removal connection, at least one part of the extraction device, a common fluid connection, and the fluid return connection, wherein the process fluid is carried in a second circuit between the extraction device and a treatment device through the common fluid connection, an extraction fluid connection, the treatment device, and at least one part of the extraction device, and wherein the first circuit and the second circuit partially overlap at the common fluid connection.