Puttng some suitable internal devices in the risercomer of a large-scale airlift loop reactor for promoting bubbles dispersion and gas-liquid mixing could enhance the oxygen transfer. The perforated plate and corrugated screen package were mainly investigated. The influence of the hole diameter and void-age of the perforated plate on KLa was studied. The results showed that smaller hole diameter and larger voidage had higher KLa values with lower hydraulic resistance. In order to measure the KLa with the dynamic method

a plug flow model for describing the transient response of dissolved oxygen concentration in the loop system with large height and diameter ratio was proposed to yield an analytic solution. The calculated results based on the model were well in accordance with the experimental data.