The utility model relates to the technical field of nylon production, and particularly provides a
polyamide 6 extraction water
evaporation and concentration device, which is characterized in that the tube pass of a first-effect
heat exchanger, the tube pass of a second-effect
heat exchanger and the tube pass of a third-effect
heat exchanger are respectively provided with a circulation loop, after circulating heat exchange and concentration, the steam enters a tube pass of a second-effect heat exchanger, enters a third-effect heat exchanger after further circulating heat exchange and concentration, and enters a fourth-effect heat exchanger and a third separator after circulating heat exchange, steam generated by a tube pass of a first-effect heat exchanger enters a first separator to be separated, and a
gas phase enters a shell pass of the second-effect heat exchanger; steam generated by tube passes of the second-effect heat exchanger and the third-effect heat exchanger enters a second separator to be separated, a separated
gas phase and a
gas phase separated by a third separator are connected to a spray washing
tower and a compressor together, and compressed steam provides steam for a shell pass of the first-effect heat exchanger and a shell pass of the third-effect heat exchanger. The device is reasonable in structural arrangement,
heat energy can be fully utilized, and energy is saved.