Normally, dissolver stirrers are operated at high or even very high circumferential speed and create a strong radial flow with high shear forces. Ideally, a torus-shaped flow is created, also referred to as the doughnut effect (not with low viscosity dispersions).
The aim of this mixing process is to have the dispersion medium enclose the surface of the particles entirely so as to prevent agglomeration or flocculation of the solids. The stirrer provides finest distribution of the dispersed phase in the dispersion medium.