Some effects of a drag reducing agent (DRA) on the performance of a stirred vessel

A study about the influence of the addition of a drag reducing agent (100 ppm PAA) to a pure liquid (water) has been conducted. It is well known that its effect in a stirred system is to decrease the power draw and to moderately increase mixing time; also, the flow field (mean velocity distribution) has been measured in recent years. This contribution is meant to implement previous findings with new data regarding the fluctuating velocity distribution in the stirred vessel (determined with PIV technique for two types of agitators, namely a Rushton turbine and an axial A310 impeller) and the effect on the particle size distribution of the solid product of a precipitation reaction (barium sulphate by reaction of barium chloride and sodium sulphate) conducted in the vessel.