Characteristics of Holdup and Mixing in a Continuous Twin-Shell Mixer

The characteristics of holdup and mixing in a continuous mixer consisting of a series of equal-size twin-shell mixer units were studied. The equation showing the holdup of solid materials in the mixer was derived by material balance. Experiments were carried out on a glass particles system and the results agreed well with predicted values. The characteristic of the mixing of glass particles in the mixer was determined by measuring the response at the outlet to a step input of a tracer. A flow model for the mixer of M twin-shell mixer units was developed by 2M perfect mixing tanks in series with the volume of half the holdup of the corresponding mixer unit. The response curve derived from the flow model agreed well with experimental data.