Section 2 Design Considerations

In this section, design considerations for a 1-kW fuel cell powered line-interactive UPS system with one hour of backup power employing modular (fuel cell and power converter) blocks is discussed. Figure 8-13 shows two commercially available PEFC fhel cells (25 to 39V, 500W) [1] along with suitable DC-DC and DC-AC power electronic converter modules. Commercially available supercapacitors [5] supply transient power at the output terminals. Two possible power-conditioning architectures are investigated. 

Sohds in divided form, such as powders, pellets, and lumps, are heated and/or cooled in chemical processing for a variety of objectives such as solidification or fusing (Sec. 11), drying and water removal (Sec. 20), solvent recoveiy (Secs. 13 and 20), sublimation (Sec. 17), chemical reactions (Sec. 20), and oxidation. For process and mechanical-design considerations, see the referenced sections. 

These are the basic maximum ratings that a current-carrying conductor can carry under ideal operating conditions. They are influenced by the service conditions and other design considerations, a.s discussed in Section 28.5. Apply suitable derating factors to arrive at the actual current ratings of these conductors under actual operating conditions. 

The discussion of the important design considerations of solid-propellant motors presented in Section I has shown the importance of the steady-state burning rate of the propellant. The particular mission for a rocket motor to... 

Design Considerations and Economics The selection among batch, fed-batch, single-pass, or continuous operation has been described earher in this section. Important performance considerations for UF applicaHons involve product purity and/or concentration, product yield, and cost/sizing for a given production rate. 

Since blast-resistant design is based on structural response beyond elastic limits into the inelastic range, buildings should be carefully designed in a manner that minimizes stress concentrations, brittle behavior, and abrupt failures. Some of the significant design considerations for steel and reinforced concrete blast-resistant structures are briefly summarized in this section. 

The split-fraction coefficients can be estimated by considering the function of the process unit, and by making use of any constraints on the stream flows and compositions that arise from considerations of product quality, safety, phase equilibria, other thermodynamic relationships and general process and mechanical design considerations. The procedure is similar to the techniques used for the manual calculation of material balances discussed in Section 4.3. 

This section discusses several material and design considerations for FMLs. It highlights some of the problems encountered in designing bathtub systems for hazardous waste landfills and describes the impact of regulations on material and design considerations. 

In spite of the drawbacks enumerated above, fluidized bed reactors have a number of compelling advantages, as we have noted previously. By proper design it is possible to overcome their deficiencies so that their advantages predominate. This book does not discuss in detail the manner in which this problem can be solved, although the design considerations outlined in subsequent sections of this chapter are quite pertinent. For detailed treatments of fluidized bed reactor design, consult the excellent reference works by Kunii and Levenspiel (3) and by Davidson and Harrison (4). 

This paper discusses the prospects for creating 3-D architectures for batteries. We next introduce calculations for the 3-D interdigitated array battery (Figure 2a). which will illustrate the design considerations under which the 3-D configuration leads to better performance than the conventional 2-D one. Other sections then discuss the prior art in small power, followed by the materials, synthetic, and fabrication approaches required to achieve 3-D designs. Finally, we review the present status of the systems most likely to demonstrate true 3-D battery operation. 

The classic texts on the design of experiments in scientific and engineering studies emphasize (1) measurement and instrumentation, (2) sources of error, (3) factor design etc. [30, 31] This section addresses step-by-step many of these issues for in situ studies, and does so by integrating relevant chemical and chemical engineering concerns and concepts. This section attempts to provide a very useful short-list of design considerations for the experimentalist so that Eq. (2) can be solved. 

The best known application of experiment design is to find the extremum of a quantity depending on further variables by observing its value at appropriately selected points (refs. 43-46). In this section, however, consideration is restricted to design methods, purported to increase the reliability of estimates when fitting a model to observations. 

Design considerations for the limestone flume are discussed elsewhere.7 8 The flume is a 500 ft long vee-section channel filled with txH in. crushed limestone to a depth of about 3 in., designed to neutralize 2 gpm of pH 4.0 mine wastewater to pH 6.3. 

In subsequent sections, examples will be used to illustrate some of the design considerations listed here. 

This chapter has mainly been based on textbooks generally used in undergraduate courses on mass transfer and separation processes.1 6 Most of these textbooks contain sections on both basic calculations as well as some design considerations. Coulson et al is devoted entirely to design. Perry,7 in addition to basic theory, also includes thermodynamic data for many common mixtures which may be used for preliminary... 

The advantages resulting from the use of a TOF-MS with a technique such as ICP-MS have been touched upon. In the following sections, it is our aim to highlight some illustrative applications, touching on aspects of instrumental performance and notable design considerations. 

General design considerations for mechanically agitated gas-liquid and gas-liquid-solid mechanically agitated reactors described earlier in Sections II and III are applicable here. In this section, however, we evaluate additional design considerations that are specific to bioreactors. Novel reactors to overcome specific needs of biological processes are also evaluated in this section. The characteristics of the bioreactors and other chemical/ petrochemical gas-liquid and slurry reactors are compared in Table XX. 

This mechanism is denoted as an EC mechanism (Testa and Reinmuth, 1961 Bott, 1997). Thus homogeneous kinetic terms may be combined with the expressions for diffusion and convection [i.e. a modified version of (18)] to give the temporal variation of the concentration of a species in an electrode reaction mechanism. In order to model the voltammetric response associated with this mechanism, a knowledge of , a, ko and k is required, or deduced from a theoretical-experimental comparison, and the set of concentrationtime equations for species A, B and C must be solved subject to the constraints of the Butler-Volmer equation and the experimental design. Considerable simplification of the theory is achieved if the kinetics for the forward and reverse processes associated with the E step are fast, which is a good approximation for many organic reactions. Section 7 describes the approaches used to solve the equations associated with electrode reaction mechanisms, thus enabling theoretical simulation of voltammetric responses to be achieved. 

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