Experimental study of mixing performance with the tridimensional rotational flow sieve tray under low Reynolds number

Abstract The mixing of fluids at low Reynolds numbers is currently attracting widespread attention. This study proposes a novel type of static mixer, the tridimensional rotational flow sieve tray (TRST). The mixing performance of the laminar flow fluid was measured using the coefficient of variation ( CoV ). We investigated the effects of the number, mode, and spacing of the mixing elements; the main fluids, tracer Reynolds number, and tracer outlet position on the mixing performance of the TRST. The results showed that the mixing performance increased with the increase in the number of elements and the Reynolds number of the main fluid. The mixing performance was better when the elements were in the backward installation than in the forward installation. The tracer Reynolds number had little effect on mixing. The mixing performance first increased and then decreased with the increase in the radial distance of the tracer outlet. With the increase in the element spacing, the mixing performance first decreased and then increased. The experimental conditions that yield the best mixing effect are as follow: eight TRSTs in a backward installation; elements spacing of 40 mm; Reynolds numbers of the main fluid and tracer as 987 and 237, respectively; and tracer outlet radial distance of 8.5 mm. The calculated CoV a values of the empirical model had an average deviation of ±12% from the experimental values. Compared with commonly used static mixers, TRST showed good mixing performance.