Molecular impeller

To determine the number of stages, using the impeller and diffuser defined as the stage, assume 10,000 ft-lb/lb of head per stage. This value can be used if the molecular weight is in the range of 28 to 30. For other... 

As noted previously, mixing in highly viscous liquids is slow both at the molecular scale, on account of the low values of diffusivity, as well as at the macroscopic scale, due to poor bulk flow. Whereas in low viscosity liquids momentum can be transferred from a rotating impeller through a relatively large body of fluid, in highly viscous liquids only... 

Example 12-3 An aqueous solution contains 10 ppm by weight of an organic contaminant of molecular weight 120, which must be removed by air oxidation in a sparger reactor at 25°C. The liquid is admitted at 1 liter/sec. The air at 1 atm is admitted at 0.5 liter/sec. An impeller disperses the air into bubbles of uniform 1 mm diameter and mixes gas and liquid very rapidly. The reaction in the hquid phase has the stoichiometry A + 2O2 —> products with a rate r =... 

Butyl methacrylate, lauryl methacrylate, and cetyl methacrylate were combined with maleic anhydride, lauryl mercaptan, and process oil and then charged into a 2-liter reaction vessel equipped with two mixing impellers rotated at 300 rpm during the reaction. The mixture was preheated to 85°C and then treated with 2,2 -azoisobutyronitrile and heated for 4 hours at 85°C followed by 1 hour at 100°C. In some cases additional oil was added to make the product more easily pourable. Unreacted maleic anhydride and other low-molecular-weight products were removed by heating the reaction mass to 120°C while applying a vacuum. Reaction scoping results are provided in Table 1. 

Notes Asterisk indicates figures applying only to high molecular weight hydrocarbons. Factors apply on one compressor body with six or less impellers. 

The first-order dependence of the deactivation constant was found to be proportional not only to the power imparted by the impeller but also to the area between the liquid and the glass wall, air surface, or poly(tetrafluoroethylene) (PTFE) surface (Colombie, 2001). Hydrophobic PTFE and air interfaces increased lysozyme inactivation fourfold over glass. In addition, the number and thus the molecular surface of inactivated enzymes, which are more hydrophobic than native enzymes, enhanced lysozyme inactivation and aggregation. 

The impelling force in these excursions of atoms up the valley sides is molecular collision. Collisions impart energy to the bromine molecules and to the molecule containing the two carbon atoms and permit them to rise to the top of the pass. In most cases the collisions are not violent enough to carry them to the top of the pass and they fall back to the valley floors. Even when a bromine atom gets to the top of the pass it can fall either way and become part of either a stable C-Br compound or a stable Br-Br molecule. At this particular position at the top of the pass... 

In summary, then, autocorrelation functions are useful mathematical devices which, when applied to velocities, tell us to what degree the motion of a particle at a given instant is related to the impelling force of the last collision. Their usefulness is mainly in molecular dynamics, the principal computer-oriented method by which systems are inaeasingly being analyzed (Section 2.17). 

The architecture of the individual instruments used to detect atoms and small free radicals by atomic and molecular resonance fluorescence or by laser-induced fluorescence is shown in Figure 13, but is discussed in detail elsewhere. Briefly, a nacelle, hollow through the core from nose to tail with an impeller in the anterior section, provides for the laminar flow of stratospheric air around and through the instrument. Detection of trace species is carried out at one (or. more) optical axes within the nacelle. A major subset of the important stratospheric radicals can be detected using the configuration shown in Figure 13. 

Molecular diffusion coefficient or diameter or impeller diameter Also used as diffusive contributions in discretized equations (Chapter 6)... 

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