Experimental methodology for measuring performance of 3D printed Coiled Flow Reactors

Coiled Flow Reactors (CFR) have been used for decades in pharmaceutical industry to create uniform continuous process mixing under laminar flow conditions. To achieve improved Residence Time Distribution (RTD) study of CFRs geometrical design parameters is required. Evaluation of production size CFRs requires extensive amount of coiled tubing, manual assembly and lab time to run a single experiment. Numerical simulations are equally problematic mainly due to meshing and convergence issues caused by complex helical geometries that define this design. Both would give a limited number of data points and it would be difficult to train optimiser to establish what would be the best combination of parameters for a given input conditions. In this paper we present methodology for scaled size reactor testing that would enable us to 3D print any number of design combination and collect process data with sufficient accuracy and repeatability. As a result we developed a test bed platform to physically measure performance of a selected reactor design. In addition, we design and 3D print custom flow-cells and reactor structures which enabled accurate measurements at a small (10mL) reactor scale. Measurement of Relative width Rw was used as the main criteria for establishing CFR performance. Results show that CFRs with higher Re numbers (60–120) performed better to the ones with lower Re number (<60). We also review how other geometrical parameters that define CFR structure (Di, Dc, Pitch and Turns) affect the final RTD.