Hydrodynamic and Mass-Transfer Characteristics of Annular Centrifugal Contactors on the Caprolactam Recovery from Waste Liquor

Caprolactam recovery from waste water is an important and challenging problem in industry. In comparison with extraction columns widely applied in the recovery of caprolactam, annular centrifugal contactor is featured by compact structure, convenient maintenance, and high throughput and efficiency with low energy consumption, etc., which have a wide application in industry. The effects of flow ratio, radius of heavy phase weir and the rotational speeds on entrainment, separation capacity and mass transfer efficiency were studied with annular centrifugal contactors for caprolactam recovery. The results show that the caprolactam with 99.99% purity, the maximum separation capacity of 109L and the highest mass transfer efficiency of 99.8% were obtained.