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Saint-Sauveur-en-Rue, France

Parida D.,CNRS The Institute of Chemistry and Processes for Energy, Environment and Health | Serra C.A.,CNRS The Institute of Chemistry and Processes for Energy, Environment and Health | Garg D.K.,Laboratoire Des Science Of Lingenieur | Hoarau Y.,Laboratoire Des Science Of Lingenieur | And 2 more authors.
Macromolecular Reaction Engineering | Year: 2014

Continuous-flow atom transfer radical polymerization of 2-(dimethylamino)ethyl methacrylate in tubular microreactors of different diameters and geometries is studied. Scale-up of tubular reactors from micro (876μm ID) to milliscales (1753 and 4083μm IDs) is investigated. Coil flow inverter (CFI) reactors having 3 and 6m length (three and seven bends, respectively) are also considered for this study. Positive effects of flow inversion are visible in all three types of reactors expressed by an increase in molecular weight and monomer conversion as well as a decrease in the PDI for the same operating parameters. An increase in reactor diameter results in an increase in the throughput. It is worthy to mention that a CFI reactor having 4083μm ID and 3m (three bends) is found to increase the throughput by ten times without significantly increasing the PDI compared to a coiled tube microreactor with 876μm ID, 6m and no flow inversion pattern. However, pressure drops are higher (+0.1 bar) in case of larger diameter tubes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Dufresne M.,British Petroleum | Dufresne M.,Laboratoire Des Science Of Lingenieur | Vazquez J.,British Petroleum | Vazquez J.,Laboratoire Des Science Of Lingenieur | And 4 more authors.
Houille Blanche | Year: 2014

This paper proposes three methodologies for the determination of discharge using water depth and velocity measurements when international standards are not applicable. Each methodology is illustrated through the use of a practical application. The first methodology deals with the instrumentation of the overflow discharge of a combined sewer overflow chamber. Even if these works are hydraulically very similar to standard weirs, their geometry is generally very complex and sometimes unique. The proposed methodology consists in a hydraulic analysis, the use of 3D computational fluid dynamics and the analysis of the simulated results in order to build simple head-discharge relationships that can be easily used by sewer managers. The second methodology deals with ultrasonic (transit-time) gauging stations where singularities have a significant influence on the link between the measured velocities and the mean velocity. The methodology for such stations is very similar to the previous one, with the exception that the models have to be chosen for simulating the velocity distribution and not only the water level distribution. Finally, the third method deals with the determination of the discharge in a sewer using two water level measurements located in two distant manholes. The methodology here consists in a hydraulic analysis, the use of the backwater curve equation (1D model) and an analysis of the simulated results to build an exploitable relationship. © 2014 Société Hydrotechnique de France . Source

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