Method of replacing dispersion medium and apparatus therefor

摘要

A method of replacing a first dispersion medium, in a starting slurry composed of the first dispersion medium and either terephthalic acid crystals or isophthalic acid crystals, with a second dispersion medium, and apparatus therefore. The starting slurry is tangentially fed to a vertically extending cylindrical portion of a cyclone-shaped nozzle disposed at an upper portion of a replacement tank of a dispersion medium replacement apparatus, from a tangential direction of the cylindrical portion, and moves circularly along an inner wall of the cylindrical portion. The slurry circularly moving is then discharged from an opening which is disposed at a vertically lower end of the cylindrical portion and dispersed in a second dispersion medium which is fed from a lower portion of the replacement tank.

主权项

1. A dispersion medium replacement apparatus for replacing a first dispersion medium in a starting slurry composed of the first dispersion medium and crystal terephthalic acid with a second dispersion medium, comprising:
(1) a dispersion medium replacement tank, (2) a cyclone-shaped nozzle positioned in an upper portion of the replacement tank, the cyclone-shaped nozzle being composed of a circular portion having a vertically extending axis and an opening disposed at a lower end, (3) a feed portion feeding the starting slurry to the cyclone-shaped nozzle, (4) a feed portion of the second dispersion medium located in a lower portion of the replacement tank, wherein the second dispersion medium flows upwardly through the replacement tank, (5) a discharge line discharging a replaced slurry mainly composed of the crystal terephthalic acid and the second dispersion medium from the lower portion of the replacement tank, and (6) a discharge line mainly discharging the first dispersion medium from the upper portion of the replacement tank; wherein: (i) the feed portion of (3) is placed in order that the starting slurry is tangentially fed to the circular portion of the cyclone-shaped nozzle so as to allow the starting slurry to move circularly along an inner wall of the circular portion, and (ii) the starting slurry which moves circularly is flown from the opening of the cyclone-shaped nozzle to contact with the second dispersion medium which flows upwardly through the replacement tank, thereby dispersing the starting slurry in the second dispersion medium.