Experimental and CFD studies on the intensified micromixing performance of micro-impinging stream reactors built from commercial T-junctions

•A micro-impinging stream reactor (MISR) with a size of ~1 mm has been built.•MISR has advantages of intensified micromixing and easy construction.•Micromixing of MISR was studied by experiment and CFD method.•The two streams impinge within MISR to achieve a quick mixing at the micro-scale.•Both operating parameters and geometric parameters of MISR affect the micromixing.

A micro-impinging stream reactor (MISR) at the size of ~1 mm has been built from commercial T-junctions and steel micro-capillaries, which has advantages of intensified micromixing and easy construction. By using a big-sized and very short outlet tube, the two injecting streams could impinge intensely within the limited chamber of the T-junction to achieve a quick mixing at the micro-scale. The effects of both operating parameters and geometric parameters of MISR, e.g., inlet jet Reynolds number (Rej), volumetric flow ratio (R), outlet configuration, outlet length (L), and inlet diameter (di), on the micromixing efficiency have been studied by experiments with the Villermaux–Dushman reaction as well as by computational fluid dynamics (CFD) method. Both experimental and numerical results agreed well and demonstrated that the inlet jet Reynolds number (Rej) and inlet size played a key role for the micromixing performance. The outlet configuration also had a great influence on micromixing, but the effects of the length of outlet channel were insignificant. This work showed that MISR will have a great potential for both reaction and separation process intensifications.