Abstract
In this experimental study, the effect of a modified 4-alternating pitched blade turbine (4-APBT) on isolated mixing regions (IMRs) was studied using a Newtonian fluid at low Reynolds numbers. The dimensionless mixing time, Ntm, was measured using direct visualization of an acid–base reaction within the Newtonian fluid. The digital image analysis of the photographs revealed that the use of 4-APBT leads to smaller IMR structure volumes (less than 20% of total liquid volume) and reduced mixing time by 60% compared to those obtained with the 4-blade disc turbine (4-DT).