Modeling and application of a semibatch coaxial two‐impinging‐stream contactor for dissolution of solids

A semibatch, coaxial, two‐impinging‐stream (TIS) contactor was developed and tested for dissolving solid particles of sodium‐nitrate, sodium‐nitrite and urea in water. The feature of the contractor lies in the possibility of increasing and controlling the mean residence time of the particles in the reactor. The mass transfer coefficients determined in the semibatch device, where the water was in a continuous flow and the particles remained in the reactor for a certain period of time, can also be applied to a continuous TIS device. The comparison of mass transfer coefficients with values of other well‐known devices indicated that they are among the highest and that the present contactor is very effective. A physical model was established for the behaviour of the dissolving particles which yielded a two‐parameter correlation for predicting the Sherwood number as a function of the operational parameters.