Of ideal plug

Non-ideal reactors are described by RTD functions between these two extremes and can be approximated by a network of ideal plug flow and continuously stirred reactors. In order to determine the RTD of a non-ideal reactor experimentally, a tracer is introduced into the feed stream. The tracer signal at the output then gives information about the RTD of the reactor. It is thus possible to develop a mathematical model of the system that gives information about flow patterns and mixing. 

The following systems represent differing combinations of ideal plug-flow, mixing, dead space, flow recycle and flow by-pass. 

This section indicates a few useful generalizations that are pertinent in considerations of isothermal series and parallel combinations of ideal plug flow and stirred tank reactors. 

Response of ideal plug flow reactor and real tubular reactor to step and impulse inputs. 

In the case of ideal plug flow Dh = 0, while in ideal mixed flow = 0. Thus, in ideal, mixed, or plug flow, the fust term is zero. 

Therefore, the holding section should be 26.8 m, which is 2.7 m longer than the result from the assumption of ideal plug flow. 

It is clear from Fig. 16.57 that the conversions can be realized up to 90 % for small NTU of 3 in a liquid-sprayed fluidized bed. It also shows that the assumption of ideal plug flow of gas (PFTR) is more appropriate than the assumption of ideal mixing of the gas (CSTR). 

Tubular reactors are often designed for steady-state operation on the basis of idealized plug flow so that Eq. (41) applies, or... 

This chapter discusses four methods of gas phase ceramic powder synthesis by flames, fiunaces, lasers, and plasmas. In each case, the reaction thermodynamics and kinetics are similar, but the reactor design is different. To account for the particle size distribution produced in a gas phase synthesis reactor, the population balance must account for nudeation, atomistic growth (also called vapor condensation) and particle—particle segregation. These gas phase reactors are real life examples of idealized plug flow reactors that are modeled by the dispersion model for plve flow. To obtain narrow size distribution ceramic powders by gas phase synthesis, dispersion must be minimized because it leads to a broadening of the particle size distribution. Finally the gas must be quickly quenched or cooled to freeze the ceramic particles, which are often liquid at the reaction temperature, and thus prevent further aggregation. 

For a given cross section of the dilute phase (this phase includes a part of the transition zone) the particles contact the ascending gas in a complicated way. Swarms of suspended particles may show a mass-transfer resistance for gas-particle contact, whereas a very dilute suspension of catalyst will not involve any appreciable mass-transfer resistance. Accordingly, one can assume that the fracticm directly ccmtacts the reactant gas the rest of the catalyst Ced in dense clusters, indirectly ccmtacts the gas with the overall mass-transfer coefficient k Oc- Under the simplifying assumption of ideal plug flow of gas through the dilute phase, the equations of continuity are given as follows ... 

In this section we indicate a few useful generalizations that are pertinent in considerations of series and parallel flow combinations of ideal plug flow and stirred-tank reactors operating isothermally. Parallel combinations are governed by the general principle enunciated in Section 8.2.3 For most efficient utilization of the available reactor volume, all parallel streams that meet must have the same composition. 

In the case of known formal kinetics, the reactor performance can be determined directly from the RTD. We can imagine, for example, that the RTD in the reactor under consideration can be represented by a series of ideal plug flow reactors of different lengths arranged in parallel through which the reaction mass flows at equal rates (see Figure 3.17). 

Ca = Cao6Xp( - A olipf) in the case of ideal plug flow and by... 

Table 11.2 Reactors That Can Be Represented as Combinations of Ideal Plug- and Mixed-Flow Configurations...

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