Thermal performance of meso-scale oscillatory baffled reactors

Abstract

This study reports the evaluation of heat transfer characteristics and pressure drops in three designs of meso-scale oscillatory baffled reactors over the net flow range Ren = 60–2500 and the oscillatory flow range Reo = 0-1600. The three designs were the oscillatory central baffled reactor (OCBR), the oscillatory helical baffled reactor (OHBR), and the oscillatory orifice baffled reactor (OOBR). The designs were evaluated in terms of “thermal performance” to take the heat transfer and pressure drop into account.Interestingly, in all designs the pressure drop was observed to decrease with increasing oscillation, due to some degree of energy recovery. In all cases, oscillating the flow significantly enhanced the Nusselt number by upto a maximum of around 10-fold. The meso-OBRs were shown to achieve higher thermal performances than steady flows in smooth tubes in all cases. Up to 480%, 460%, and 300% improvements in thermal performance was achieved for the OHBR, OCBR, and OOBR, respectively. The OHBR exhibited the lowest pressure drop, resulting in the highest thermal performance of the designs investigated here. Hence, on the basis of this study, the OHBR design is recommended. New empirical correlations for predicting pressure drop and Nusselt number were established for each design, with data mostly lying in the range ±30% of the correlations.