Solvent replacement device and method for increasing CTA solvent substitution rate

摘要

The present invention relates to a solvent exchanger and a method for improving the exchange efficiency of a CTA solvent. The method comprises the following steps: (1) pressurizing a CTA slurry into a solvent exchanger for separation, and respectively obtaining a mother liquor, a bias flow mother liquor and a suspended matter A; (2) washing the suspended matter A to respectively obtain a primary filtrate, a bias flow primary filtrate and a suspended matter B; (3) washing the suspended matter B to respectively obtain a secondary filtrate, a bias flow secondary filtrate and a suspended matter C; (4) washing the suspended matter C to respectively obtain a third filtrate, a bias flow third filtrate and a suspended matter D; (5) washing the suspended matter D to respectively obtain a fourth filtrate, a bias flow fourth filtrate and a suspended matter E; (6) washing the suspended matter E to respectively obtain a fifth filtrate, a bias flow fifth filtrate and a filter cake, wherein the bias flow fifth filtrate is guided to a bias flow filtrate tank by a suction machine unit; and (7) after the washing is finished, back-flushing the filter cake and then pulping to obtain a slurry, and discharging. By means of improvements in both the technological process and the equipment structure, the present invention greatly reduces the energy consumption and improves the solvent exchange efficiency.