bubble column has several floors, has punched plates

This invention relates to a bubble column multistage having three or more than three perforated plates (3) placed in contact with the inner wall of column (6), which have perforations distributed non-uniformly. The ratio of the total surface voids of each perforated plate on the cross-sectional area of ​​the cell column is 15% or less, and which has good efficiency of mixing or reaction.