A liquid-gas phase reactor system including a slinger located in an upper section (headspace region) of a reaction vessel. The slinger comprises an upper horizontal surface including a plurality of vertically raised vanes extending radially outward along a curved path which effectively distribute liquid about the reactor vessel. A method for conducting an oxidation reaction using a liquid-gas phase reactor system is also disclosed. The disclosed reactor system and method have a broad range of applications but are particularly suited for the production of terephthalic acid.