Cold model study on mass transfer between different phases in a mechanically stirred vessel

The effects of operating conditions on liquid/liquid or solid/liquid mass transfer rate in a mechanically stirred vessel were investigated. Benzoic acid transfer rate from dispersed liquid paraffin to continuous ion-exchanged water was measured in a liquid/ liquid system, whereas ion-exchanged reaction rate between pearlite particles on Na⁺ and dilute hydrochloric acid solution in a solid/ liquid system. Both of liquid/liquid and solid/liquid mass transfer rates strongly depended on the mixing patterns between different phases. They were kept to be nearly constant in the region I where the liquid/liquid or solid/liquid interface did not touch a impeller, monotonically increased in the region II where the phase interface attained at impeller position except near the region III where gas/ continuous liquid interface arrived at the impeller, and their increasing rates decreased in the latter part of the region II and in the region III. The solid/liquid mass transfer rate changed less than the liquid/liquid one in the region II.