Can 3D printing solve the numbering-up challenge of microfluidic reactors?

Successful studies concerning numbering-up two-phase flow in microreactors remain scarcely published and involve highly specialized experimental configurations. In present study we bring forward a reproducible production method for manifolds, constructed only from commercially available and 3D printed parts, with the aim of seeding future studies in this field of research. Manifolds of five parallel channels were produced from commercial tubes and fittings and 3D printed parts. The maldistribution was assessed using water (Re = 10.58- 84.63 and Ca = 2E-5- 0.006) and n-dodecane (Re = 5.93- 47.48 and Ca = 2.69E-5- 0.008) for a constant flowrate of 5 mL min-1 phase-1. Firstly, it was found that tubes and fittings alone cannot produce reliable and reproducible manifolds. Secondly, a hybrid manifold, consisting of a SLA printed distributor and commercial tubes and fittings, was investigated. The latter reduced the maldistribution by at least a factor of 2, for both single- and two-phase flow, and consists only of commercially available or "outof-the-box" printable parts. Finally, it is also shown that the surface tension of applied liquid affects the maldistribution significantly, presumably due to the presence of air bubbles.& COPY; 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.