Patent ID: 9333442
Filing Date: 2016-05-10
CPC Classification: B01D,C07C,C10G

Claim Text:
1. A counter-current liquid-liquid extraction column comprising: a column having a diameter and upper, middle and lower parts, a plurality of spaced perforated plates with associated downpipes, each downpipe having an inlet and an outlet, wherein said perforated plates with associated downpipes comprise a number of open plates between 4 and 25, defined by a degree of perforation p % of between 2% and 6% of the empty cross-section of the column, and a number of closed plates between 1 and 3, wherein each closed plate is defined by a degree of perforation between 0.3 and 0.5 times that of the open plates, each closed plate is situated between two open plates so that each closed plate is adjacent to two open plates, said closed plates are situated in the middle part of the column, wherein said downpipes associated with the closed plates have cross-sections between 0.25 and 1 times the cross-sections of the downpipes associated with the open plates, and said downpipe associated with at least one of said closed plates comprises a part crossing the column substantially along the diameter of said column, so that the outlet of said downpipe is located opposite the inlet of said downpipe relative to the cross section of said column.