Couette-Taylor flow reactors

The Couette-Taylor flow reactor consists of two concentric cylinders in which the outer one is fixed and jacketed, while the inner one rotates. Under some particular conditions, a flow pattern characterized by counter-rotating toroidal vortices is formed. This Couette-Taylor flow makes the RTD in this reactor similar to that of a train of CSTRs [74]. However, because viscosity may change substantially as polymerization proceeds (along the reactor), it is difficult to maintain the required Taylor number in the whole reactor. The use of a conical outer cylinder may counteract the viscosity increase [75]. However, no example of the production of a commercial-like latex (i.e., high solids content) has been reported. 

Dluska, E., Wronski, S. and Hubacz, R. (2001). Mass transfer in gas-liquid Couette-Taylor flow reactor. Ghemical Engineering Science, Vol. 56, pp. 1131-1136. 

Desmet G., Vereist H., Baron G.V., Local and global dispersion effects in Couette-Taylor flow I. Description and modeling of the dispersion effects IL Quantitave measurements and discussion of the reactor performance, Chem. Eng. Sci. 51 (1996) 8, p. 1287-1298 and 1299-1309... 

Vaezi, V., E. S. Oh, and R. C. Aldredge. 1997. High-intensity turbulence measurements in a Taylor-Couette flow reactor. J. Experimental Thermal Fluid Science 15 424-31. 

Preparation of Monodisperse, Spherical Oxide Particles by Hydrolysis of Metal Alkoxide Using a Couette-Taylor Vortex Flow Reactor... 

As an alternative to a cascade of CSTR trains, a novel continuous reactor with a Couette-Taylor vortex flow (CTVF) has been proposed, which can realize any flow pattern between plug and perfectly mixed flows [361-366]. A continuous Couette-Taylor vortex flow reactor (CCTVFR) consists of two concentric cylinders with the inner cylinder rotating and with the outer cylinder at rest. Figure 29 shows a typical flow pattern caused by the rotation of the inner cylinder. 

Nomura et al. [360,364] first utilized a Couette-Taylor vortex flow reactor (CTVFR) for the continuous emulsion polymerization of St to clarify its char-... 

Couette-Taylor Continuous emulsion pol)mierization of styrene in a Couette-Taylor vortex flow reactor comprehensive kinetic study in dependence on reactor operation parameters 179... 

The Taylor-Couette reactor (TCR), sometimes referred to as a vortex flow reactor, consists of two concentric cylinders, one of which rotates. Figure 5.23. 

Reactor configurations involved in continuous emulsion polymerization include stirred tank reactors, tubular reactors, pulsed packed reactors, Couett-Taylor vortex flow reactors, and a variety of combinations of these reactors. Some important operational techniques developed for continuous emulsion polymerization are the prereactor concept, start-up strategy, split feed method, and so on. The fundamental principles behind the continuous emulsion polymerizations carried out in the basic stirred tank reactor and tubular reactor, which serve as the building blocks for the reaction systems of commercial importance, are the major focus of this chapter. 

If a fluid is placed between two concentric cylinders, and the inner cylinder rotated, a complex fluid dynamical motion known as Taylor-Couette flow is established. Mass transport is then by exchange between eddy vortices which can, under some conditions, be imagmed as a substantially enlranced diflfiisivity (typically with effective diflfiision coefficients several orders of magnitude above molecular difhision coefficients) that can be altered by varying the rotation rate, and with all species having the same diffusivity. Studies of the BZ and CIMA/CDIMA systems in such a Couette reactor [45] have revealed bifiircation tlirough a complex sequence of front patterns, see figure A3.14.16. 

Reactors which generate vortex flows (VFs) are common in both planktonic cellular and biofilm reactor applications due to the mixing provided by the VF. The generation of Taylor vortices in Couette cells has been studied by MRM to characterize the dynamics of hydrodynamic instabilities [56], The presence of the coherent flow structures renders the mass transfer coefficient approaches of limited utility, as in the biofilm capillary reactor, due to the inability to incorporate microscale details of the advection field into the mass transfer coefficient model. 

On-going research is focused on various aspects starting from improving the reactor hydrodynamics to the catalyst development. Several new reactor designs (Fig. 2) with possibilty of scale-up are available (38 0). An improved reactor design is recently published where reactor perfromace is improved by inducing Taylor-Couette flow (41). 

Dr Coney (1971) researched Taylor vortex flow with particular interest in rotary heat exchangers, which he later used in a rotary vapour compression cycle heat pump. Taylor-Couette flows are used in commercial intensified reactors now (see Chapter 5). 

Giordano, R.L.C., Giordano, R.C. and Cooney, C.L. (2000). Performance of a continuous Taylor-Couette-Poiseuille vortex flow enzymic reactor with suspended particles. Process Biochemistry, Vol. 35, No. 10, pp. 1093-1101. 

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