For mixers it is customary to work in terms of the dispersed phase values for NTU and HTU. For linear systems the continuous-phase equations will give identical final results. Following Eq. (16-82), the definition of HO–ED in an extraction mixer is
It is also often very useful to note that because nO–ED = h/HO–ED, we can write nO–ED as
QD is the volumetric flow rate (m3/s) of the dispersed phase, and Vmixer is the total volume of the mixer (m3). The term Vmixer/QD is ...