Process and apparatus for gassing liquids

摘要

The invention provides a process for multistep gassing of liquids streaming downward in a gassing apparatus, which comprises using a gassing apparatus consisting of at least two superposed downstream parts, wherein the gas is fed in at the upper end of each downstream part and fresh gas is fed in exclusively at the upper end of the lowest downstream part, the gas bubbles are separated at the lower end of each downstream part and the separated gas bubbles are discharged to the outside and recycled to the next downstream part above. The invention provides furthermore a corresponding gassing apparatus.