Investigations of mixing and heat transfer in a structured tube‐in‐tube millireactor by numerical, experimental and statistical methods

Abstract Millireactors are widely used in flow chemistry due to their process intensification performance and sufficient product throughout. A novel structured tube‐in‐tube millireactor with industrial potential was designed, whose mixing and heat transfer were investigated by experiment and CFD. Partial least square regression (PLS) was introduced in the flow chemistry study and used to determine that the key parameters of the millireactor were jet Reynolds ( ) and hole diameter . The introduction of twist tape in the annular space generates swirling flow, which effectively increases the heat transfer capacity (up to 16.5 times). This millireactor achieves excellent mixing (>99% of mixing intensity after 1 cm) and the heat transfer enhancement ratio up to 6.5. The local flow field and concentration field from CFD model agreed with those obtained from PIV and PLIF visualization experiments.