Mixing Performance of Planar Oscillatory Flow Reactors with Liquid Solutions and Solid Suspensions

Abstract

The mixing performance of planar oscillatory flow reactors (planar-OFRs) with liquid solutions and solid suspensions was investigated. The planar-OFR is a relatively new variant of the OFR where the conventional sharp-edged periodic constrictions are replaced with smooth periodic constrictions and the conventional circular cross-section is replaced with a rectangular cross-section. The experimental results show that both the minimum mixing intensity required to fully suspend solids and the time required to reach a specific degree of concentration uniformity after injection of a liquid or solid tracer largely depend on the operating conditions, such as the frequency and amplitude of oscillation and the geometric parameters, such as the cell aspect ratio and the ratio of the open constriction area to the straight section area, in the planar-OFR.

Impact of residence time distributions in reacting magnesium packed beds on Grignard reagent formation – pump-induced flow behaviour in non-reacting magnesium beds (part 1)

“…While maintaining intense convection due to the oscillation, low flow rates are possible, allowing for a compact set-up with reduced axial dispersion. 8 This oscillatory flow concept utilising baffles or even without baffles has been used not only for gas-liquid [9][10][11][12][13][14][15][16] and liquidliquid reaction systems [17][18][19][20][21] but also for solid-containing [22][23][24][25][26][27][28][29][30][31] reaction systems. The platform SciFinder refers to 3782 publications from 1950 to 2022 considering the term "oscillatory flow" with a steady increase in publications per year, showing the rising interest in and application of this reactor concept.…”

“…Some literature reviews do exist, dealing with the concept of oscillatory flow reactors (OFRs) and giving an overview of the broad potential and applications of this specific reactor type. 3,8,[32][33][34][35] Investigated solid-containing reaction systems operated under oscillating flow conditions consider solid particles being suspended in the fluid on the one hand [27][28][29]31 and being placed in packed beds on the other hand. 23,24,30,[36][37][38] For packed beds, the application of baffleless reactors 36,39,40 and baffled reactors 23,24,30,41,42 is mentioned in the literature.…”

Impact of residence time distributions in reacting magnesium packed-beds on Grignard reagent formation – Pump-induced flow behaviour in non-reacting magnesium beds (part 1)

“…By superimposing an oscillating flow on the main flow, vortices are generated at the backside of the baffles that cause intense mixing within the vortices and improved heat and mass transfer. 3 This oscillatory flow concept utilising baffles or even without baffles has been used for gasliquid [4][5][6][7][8][9][10][11] and liquid-liquid reaction systems [12][13][14][15][16] but also for solid-containing [17][18][19][20][21][22][23][24][25][26] reaction systems. The platform SciFinder refers to 3782 publications from 1950 to 2022 considering the term "oscillatory flow" with a steady increase in publications per year, showing the rising interest in and application of this reactor concept.…”

“…Some literature reviews do exist, dealing with the concept of oscillatory flow reactors (OFR) and giving an overview of the broad potential and applications of this specific reactor type. [27][28][29][30][31][32] Investigated solid-containing reaction systems operated under oscillating flow conditions consider on the one hand solid particles being suspended in the fluid [22][23][24]26 and on the other hand being placed in packed beds. 18,19,25,[33][34][35] In the case of the flow tube reactor used in this publication, it is not a COBR type reactor, but a tubular reactor fitted with a packed bed of magnesium turnings.…”

Continuous Production of Highly Tuned Silk/Calcium-Based Composites: Exploring New Pathways for Skin Regeneration

“…Continuous flow regimes operated through oscillatory flow reactors (OFRs) provided with smooth periodic constrictions (SPCs) improved mixing efficiency and mass transfer processes in multiphase systems, generating a product with uniform and controlled characteristics [ 12 , 13 ]. The liquid or multiphase fluid is typically oscillated in the axial direction and this motion interacts with the SPCs forming vortices, the mixing intensity being controlled by the oscillation frequency ( f ) and amplitude ( x 0 ) [ 12 , 14 ]. Moreover, these reactors allow upscaling by adding identical meso-OFRs in series without compromising the chemical composition and efficiency [ 12 , 15 ].…”