Length scales reaction, table

Here Sho is the Sherwood number corresponding to mass transfer of a particle in a stagnant medium without the reaction. Each summand in (5.3.6) must be reduced to a dimensionless form on the basis of the same characteristic length. The value of Sho can be determined by the formula Sho = all/S , where a is the value chosen as the length scale and, is the surface area of the particle the shape factor II is shown in Table 4.2 for some nonspherical particles. 

Eq. 3. Thus, the data is consistent with pseudo first order kinetics for the hydrolysis furthermore, the absence of any induction period points to a spatially homogeneous hydrolysis reaction on the mentioned length scale. The corresponding rate constants are summarized in Table 2. 

Figure 2-13 shows the gross characteristics of the velocity and concentration spectra. For a low viscosity liquid. Sc can be on the order of 1000, so the Batchelor scale can be 30 times smaller than the Kolmogorov scale. The ultimate scale of mixing needed for reaction is the size of a molecule, so in liquid-phase reactions, molecular diffusion is critically important for the final reduction in scale. For a gas, Sc is closer to 1, so the ratio is closer to 1, and the competition between the turbulent reduction in scale and molecular diffusion occurs at the same range of wavenumbers. The various length scales shown in Figure 2-13 are also summarized in Table 2-3... 

Meccaniche Modeme (Busto Arsizo, Italy) acquired rights to the original AUied Chemical Company s concentric SO sulfonation unit (272). Table 10 shows comparative data on AUied s U.S. design, and that for Meccaniche Modem s concentric design, indicating equivalency. This unit has a substantial space between reactor walls, hence it requires a 6 m length to complete reaction. The process has been scaled up to 4.0 t/h capacity. 

The length and the distribution of chain lengths are functions of the temperature, pressure, residence time, catalyst characteristics, and the proportion of ethylene present in the reaction, A measure of this is the mole ratio of ethylene, which measures the weight of ethylene compared to the weight of triethyl aluminum in scales related to their atomic weights. As an example, Table 15-2 shows how the distribution of chain lengths can vary, using different mole ratios of ethylene to triethyl aluminum. 

Yields are always almost quantitative within 1-2 min, irrespective of chain length and the nature of the halide leaving groups. This procedure was scaled up from 50 mmol to the 2 mol scale (i.e. from 15.6 to 622.4 g total starting materials) in a larger batch reactor (Synthewave 1000 from Prolabo) [12]. Yields were equivalent to those obtained under similar conditions (5 min, 160 °C) in laboratory-scale experiment (Synthewave 402) vith nearly equivalent set of conditions of reaction time, temperature, and emitted electric power (Table 6.2). 

Table 2.2 presents the evolutions of these quantities for three types of scale dependence of the operation time m = 0, 1 and 2. For heterogeneous reaction and heat/mass transfers, maintaining either the channels number or their length while reducing the radius induces systematically an increase in the reactor pressure drop that can even become prohibitive. However, by choosing an appropriate channel number and channel length, the pres sure drop for these reactors can be maintained or even reduced. However, this is generally combined with an increase in the reactor cross-section. 

The characteristic length and time scales associated with detonation oscillation are found to be proportional to the nominal chemical reaction time within the detonation wave. In the present experiments, a very sensitive mixture, stoichiometric acetylene-oxygen (C2H2 - - 2.5 O2) at moderate initial pressure (200-250 Torr), with an extremely short reaction time (less than 0.1 fis) was chosen to minimize these nonideal effects. The initial conditions and computed CJ detonation characteristics of the nominal test mixture (250 Torr initial pressure and a CJ wave velocity of 2363.4 m/s) are given in Table 1. Trans-... 

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