Stirred-flow reactor design

Trambouze, P. J., and Piret. E. L. "Continuous Stirred Tank Reactors Designs for Maximum Conversions of Raw Material to Desired Product, AIChE J. 5, 384 (1959). van de Vusse, J. G. "Plug Flow Type Reactor vs. Tank Reactor, Chem. Eng. Sci. 19, 994 (1964). Viswanathan. J. V., and Grossmann, I. E. "A Combined Penalty Function and Outer-Approximation Method for MINLP Optimization, Compul. Chem. Eng. 14, 769-782 (1990). 

Various designs of the stirred-flow reactor are possible. Carski and Sparks (1985) developed a relatively simple stirred-flow reactor constructed from a plastic syringe and membrane filter holder (Fig. 2-8). The volume of the reactor is adjustable to allow one to add and maintain a known amount of solution to a known amount of solid phase. Mixing is accomplished by a magnetic stirrer. 

Iodate-Chlorite System, J. Am. Chem. Soc. 103, 2133-2134 (IIIL) De Kepper, P., Epstein, I. R., Kustin, K. Systematic Design of Chemical Oscillators 1981-2 Part 3. Bistability in the Oxidation of Arsenite by Iodate in Stirred Flow Reactor, J. Am. Chem. Soc. 103, 6121-6127... 

Dateo, C. E. Orban, M. De Kepper, R Epstein, I. R. Systematic design of chemical oscillators. 5. Bistability and oscillations in the autocatalytic chlorite-iodide reaction in a stirred flow reactor. J. Am. Chem. Soc. 1982,104, 504-509. 

Continuous-Flow Stirred Tank Reactor (CSTR) Flow reactor designed to achieve a perfect mix of all reactants in its tank sometimes called a backmix reactor. 

Wet Oxidation Reactor Design. Several types of reactor designs have been employed for wet oxidation processes. Zimpro, the largest manufacturer of wet oxidation systems, typically uses a tower reactor system. The reactor is a bubble tower where air is introduced at the bottom to achieve plug flow with controlled back-mixing. Residence time is typically under one hour. A horizontal, stirred tank reactor system, known as the Wetox process, was initially developed by Barber-Cohnan, and is also offered by Zimpro. 

Continuous-flow stirred-tank reactors ia series are simpler and easier to design for isothermal operation than are tubular reactors. Reactions with narrow operating temperature ranges or those requiring close control of reactant concentrations for optimum selectivity benefit from series arrangements. 

This chapter treats the effects of temperature on the three types of ideal reactors batch, piston flow, and continuous-flow stirred tank. Three major questions in reactor design are addressed. What is the optimal temperature for a reaction How can this temperature be achieved or at least approximated in practice How can results from the laboratory or pilot plant be scaled up ... 

Reactor design usually begins in the laboratory with a kinetic study. Data are taken in small-scale, specially designed equipment that hopefully (but not inevitably) approximates an ideal, isothermal reactor batch, perfectly mixed stirred tank, or piston flow. The laboratory data are fit to a kinetic model using the methods of Chapter 7. The kinetic model is then combined with a transport model to give the overall design. 

As will be shown later the equation above is identical to the mass balance equation for a continuous stirred-tank reactor. The recycle can be provided either by an external pump as shown in Fig. 5.4-18 or by an impeller installed within the reaction chamber. The latter design was proposed by Weychert and Trela (1968). A commercial and advantageously modified version of such a reactor has been developed by Berty (1974, 1979), see Fig. 5.4-19. In these reactors, the relative velocity between the catalyst particles and the fluid phases is incretised without increasing the overall feed and outlet flow rates. 

Consider the schematic representation of a continuous flow stirred tank reactor shown in Figure 8.5. The starting point for the development of the fundamental design equation is again a generalized material balance on a reactant species. For the steady-state case the accumulation term in equation 8.0.1 is zero. Furthermore, since conditions are uniform throughout the reactor volume, the material balance may be... 

SUMMARY OF FUNDAMENTAL DESIGN RELATIONS—COMPARISON OF ISOTHERMAL STIRRED TANK AND PLUG FLOW REACTORS... 

The ideal continuous stirred tank reactor is the easiest type of continuous flow reactor to analyze in design calculations because the temperature and composition of the reactor contents are homogeneous throughout the reactor volume. Consequently, material and energy balances can be written over the entire reactor and the outlet composition and temperature can be taken as representative of the reactor contents. In general the temperatures of the feed and effluent streams will not be equal, and it will be necessary to use both material and energy balances and the temperature-dependent form of the reaction rate expression to determine the conditions at which the reactor operates. 

Tajbl, Simons, and Carberry lnd. Eng. Chem. Fundamentals, 5 (171), 1966] have developed a stirred tank reactor for studies of catalytic reactions. Baskets containing catalyst pellets are mounted on a drive shaft that can be rotated at different speeds. The unit is designed for continuous flow operation. In order to determine if... 

In this chapter, we develop the basis for design and performance analysis for a CSTR (continuous stirred-tank reactor). The general features of a CSTR are outlined in Section 2.3.1, and are illustrated schematically in Figure 2.3 for both a single-stage CSTR and a two-stage CSTR. The essential features, as applied to complete dispersion at the microscopic level, i.e., nonsegregated flow, are recapitulated as follows ... 

Chemical reactors intended for use in different processes differ in size, geometry and design. Nevertheless, a number of common features allows to classify them in a systematic way [3], [4], [9]. Aspects such as, flow pattern of the reaction mixture, conditions of heat transfer in the reactor, mode of operation, variation in the process variables with time and constructional features, can be considered. This work deals with the classification according to the flow pattern of the reaction mixture, the conditions of heat transfer and the mode of operation. The main purpose is to show the utility of a Continuous Stirred Tank Reactor (CSTR) both from the point of view of control design and the study of nonlinear phenomena. 

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