Abstract
Reactor vessels with batch operation have been widely used in ferrous and non-ferrous production. In the production processes, more than one liquid phase is usually contained in the vessel, and it is desirable to discharge each phase separately as fast as possible. In separating two co-existing liquids, the liquid of the bottom layer is usually discharged through a nozzle located at the bottom of the vessel. However, as the liquid-level lowers with discharging of the liquid, a swirling flow generates, and the discharging rate of the liquid decreases. Moreover, the liquid of the upper layer is caught by the swirling flow, and the upper liquid begins to discharge along with the bottom liquid. In the present study, a method to prevent the generation of swirling flow during the discharge of the liquid from the vessel has been examined by water-model experiments. The time taken for discharging water rapidly increases as the water level at which the air-core forms is higher. The prevention of the generation of the air-core is an essential factor in discharging and in separating two coexisting liquid phases at high speed. It is found that the installment of a cylindrical object around the nozzle entrance is very effective for preventing the generation of swirling flow and the formation of an air-core.
