Annular configuration

A pilot plant scale, tubular (annular configuration) photoreactor for the direct photolysis of 2,4-D was modeled (Martin etal, 1997). A tubular germicidal lamp was placed at the reactor centerline. This reactor can be used to test, with a very different reactor geometry, the kinetic expression previously developed in the cylindrical, batch laboratory reactor irradiated from its bottom and to validate the annular reactor modeling for the 2,4-D photolysis. Note that the radiation distribution and consequently the field of reaction rates in one and the other system are very different. 

Table 26.1 Radial intensity equations for parallel plate, cylindrical, and annular configurations (based on the approximate incidence model) (adapted from Roger and Villermaux, 1986)... 

The radial annular active core dimensions, in combination with the choice of the outer reflector dimensions allow the maximum power rating while providing a cooling pathway to the vessel wall to assure acceptable fuel temperatures during passive decay heat removal. The annular configuration allows a 350... 

Rovinsky, J., Brauner, N. Moalem Maron, D. (1997). Analytical solution for laminar two-phase flow in a fully eccentric core-annular configuration. International journal of multiphase flow, 23, 523-543. 

Beretta, Forzatti and co-workers also studied the oxidative dehydrogenation of ethane and propane in short contact time reactors. Experiments were first performed in an isothermal, single channel reactor with an annular configuration (wherein the fluodynamics were simple, mass transfer coefficients were known and catalyst temperature was well controlled and easily measured, as illustrated in the following) the comparison between the results obtained in the absence of the catalyst with those obtained with increasing amounts of catalyst confirmed that olefins were uniquely produced via gas-phase reactions, while the Pt/Al203 catalyst was a non-selective oxidation catalyst (producing only COx, H2 and H2O). 

The validation of the heat-transfer and crystal-growth computations in the complete furnace can be extremely difficult due to uncertainty in the properties of different materials, and the necessity to quantify a complete set of test conditions and provide a comprehensive set of measurements of major parameters with the error estimates. Thus, a decomposition of the system into a hierarchy of subproblems can be useful [48]. A few model problems inspired by crystal growth are listed in ref. [53] including an annular configuration (a cylindrical container with a small coaxial cylindrical heater) that can be used to study thermocapiUary convection and a half-zone [54] that emulates the liquid bridge of the melt in the floating-zone method. 

BI SERT Blenders. The design of a BINSERT blender consists of a hopper-within-a-hopper, both of which ate usually conical ia shape (Fig. 15). Particles flow through the inner hopper as well as through the annulus between the inner and outer hoppers. By varyiag the relative position of these two hoppers as well as the configuration of the outlet geometry, it is possible to achieve between a 5 1 and 10 1 velocity differential between particles ia the inner hopper compared to particles ia the outer annular region (7,17). 

The axial flow compressors in aero gas turbines are heavily loaded. The aspecl ratio of the blades, especially the first few stages, can be as high as 4.0, and the effecl of streamhne curvature is substantial. The streamline configuration is a function of the annular passage area, the camber and thickness distribution of the blade, and the flow angles at the inlet and outlet of the blades. The shafts on these units are supported on antifriction bearings (roller or ball bearings). 

Figure 12-9. Cross section of an annular combustor showing high dome flow configuration. (Courtesy of General Electric Company.)...

Dukler and Taitel, 1991b). The simplest configuration of annular flow is a vertical falling film with concurrent downward flow. Given information on interfacial shear and considering the film to be smooth, the film thickness and heat transfer coefficient between the wall and the liquid film can be predicted from the following basic equations (Dukler, 1960) ... 

Figure 11.6 illustrates the general configuration of a film blowing operation. Molten polymer from the extruder is pumped into an annular die, where it is distributed around a tubular melt channel before emerging vertically as a relatively thick-walled molten tube. The top of... 

The examples in Scheme 2-1 show that in intra-annular chirality transfer the resident asymmetric center connects to the enolate through annular covalent bonds. The geometric configuration of the enolate can be either immobile or irrelevant to the sense of asymmetric induction. 

Figure 1 Diagrams showing the essential electron-optical configurations used for various imaging modes in CTEM and STEM as seen by two points A and B on the sample, (a) CTEM axial bright field, (b) CTEM tilted dark field, (c) CTEM hollow cone dark field, and (d) STEM with bright field and annular dark field detectors.

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