Implementation of ‘chaotic’ advection for viscous fluids in heat exchanger/reactors

Abstract

OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 17719 A B S T R A C TWhen viscous fluids are involved, laminar hydraulic conditions and heat and mass transfer intensification are conflicting phenomena. A channel geometry based on Split-And-Recombine (SAR) patterns is experimentally investigated. The principle implements the Baker's transformation and 'chaotic' structures are generated to promote heat and mass transfer. This work assesses the energy efficiency of different heat exchanger/reactors integrating these SAR patterns.The heat transfer capacity is assessed and compared with the energy consumption of each mock-up. It is sensitive to the cooling mode and to the number of SAR patterns per length unit as well.The continuous oxidation of sodium thiosulfate with hydrogen peroxide has been implemented. Conversions up to 99% are reached according to the utility fluid temperature and the residence time.Finally, the whole performances of the SAR geometries are compared to a plate-type heat exchanger/ reactor with a corrugated pattern. The more viscous the fluid, the more the energy efficiency of the SAR design increases compared to the corrugated design because of the balance between advection and diffusion mechanisms. The interest in terms of energy efficiency in working with SAR heat exchanger/ reactor appears from Reynolds numbers below 50.

Continuous Preparation of Semiconducting Polymer Nanoparticles with Varied Sizes for Online Fluorescence Sensing via a Laser-Tailored 3D Microfluidic Chip

“…As revealed in Figure B, COMSOL numerical simulation displayed complete mixing was achieved when the two phases meet at the third mixing unit when Q H 2 O = 500 μL/min and Q THF = 250 μL/min. Our 3D microfluidic chip may enhance the fluid contact area at the same length and enhance the fluid reaction time, improving the mixing process as compared to the traditional 2D microfluidic chip. − In addition, the solvent phase is usually organic, which can corrode some microfluidic channels made of PMMA or PDMS materials, leading to inaccuracy in the synthesized nanoparticle batches. In contrast, our 3D microfluidic chip was constructed of glass, which significantly reduces the interference induced by channel corrosion and distortion.…”

“…Intriguingly, the extremely small reaction volume in the microfluidic chip boosts the reaction rate and shortens the detection time within the chip channel, which can considerably reduce the sample consumption and realize the biochemical analysis at a microliter level. In response to the rising demand for high-effective reactions, 3D-structured microfluidic chips have been increasingly investigated because they have a larger contact area than two-dimensional (2D) microfluidic chips in the same length of channel. − …”

Residence time distributions for in-line chaotic mixers

“…The MLLM [21][22][23] has a three-dimensional configuration intended to mimic the baker's map. The computational geometry used is shown in Fig.…”

Residence time distributions for in-line chaotic mixers

“…The multi-level laminating mixer (MLLM) [21][22][23] has a three-dimensional configuration intended to mimic the baker's map. The computational geometry used is shown in figure 1b, with six elements represented.…”