Chapter 6 Line Sizing

The various items of equipment in the production facility are connected hy valves, fittings, and piping to enable and control flow from one piece of equipment to another. Chapter 9 of Volume 1 discusses factors governing the choice of line size and wall thickness. This chapter describes the various types of valves and fittings commonly used in production facilities and presents some common piping details and specifications. 

This chapter provides an overview of the process design work. The rest chapters of this book will provide mote information of the frequently used equipment/instrument in the process design work, such as pumps, compressors, heat exchangers, vessels, control valves, and pressure relief devices, or the task, such as line sizing. 

Fluid to be handled Identify the fluid to be handled is a process fluid or a utility fluid (such as steam, cooling water). Next identify it is single phase flow (vapor or liquid only), two phase flow, gravity flow, oratimy flow. Also check whether the fluid is Newtonian fluid or not. For Newtonian fluid, its viscosity is constant at fixed operating conditions (temperature and pressure). This chapter vvdit discuss line size for Newtonian fluid only. 

TTie loss coefficient (K) of fittings and block valves are function of Reynolds number and the nominal line size (dfl, in inch). The three K (Kl, Ki, and Kd> and equivalent line length (U,) of different fittings and block valves are listed in Table 3. Eq. (30b) is used to calculate control valve K with known inlet line tnside diameter D (in fl), and control valve sizing coefficient (Cv). Control valve pressure drop calculation by this method is a rough estimate, For more accurate control valve pressure drop calculation, the methods in Chapter 7 should be used. 

Funetions with higher 1-values and with sizes more in line with those of the lower-1 orbitals are also used to introduee additional angular eorrelation into the ealeulation by permitting polarized orbital pairs (see Chapter 10) involving higher angular eorrelations to be formed. Optimal polarization funetions for first and seeond row atoms have been tabulated (B. Roos and P. Siegbahn, Theoret. Chim. Aeta (Berl.) 17, 199 (1970) M. J. Friseh, J. A. Pople, and J. S. Binkley, J. Chem. Phys., 3265 (1984)). 

Unquestionably the best way to achieve that end would have been to rewrite the book, to expand its size and its scope, along some lines which are still unconventional but hold out promise for future interest. The prospect of undertaking this frightened us. Also, we acknowledge that there already exists a monumental treatise of this elaborate sort, dedicated to the standard parts of the newer mathematics, in the work of Morse and Feshbach, whose excellence would be hard to approach. We, therefore, decided upon the less ambitious course of editing a work which offers what we regard as the most important components of today s useful mathematics in separate chapters written chiefly by experts. 

In the past two decades, 129Xe NMR has been employed as a useful technique for the characterization of the internal void space of nanoporous materials. In particular, the xenon chemical shift has been demonstrated to be very sensitive to the local environment of the nuclei and to depend strongly on the pore size and also on the pressure [4—6], Assuming a macroscopic inhomogeneity resulting from a distribution of adsorption site concentrations, 129Xe NMR spectra of xenon in zeolites have been calculated, and properties such as line widths, shapes as well as their dependence on xenon pressure can be reproduced qualitatively. A fully quantitative analysis, however, remains difficult due to the different contributions to the xenon line shift. (See Chapter 5.3 for a more detailed description of Xe spectroscopy for the characterization of porous media.)... 

Attrition of particulate materials occurs wherever solids are handled and processed. In contrast to the term comminution, which describes the intentional particle degradation, the term attrition condenses all phenomena of unwanted particle degradation which may lead to a lot of different problems. The present chapter focuses on two particular process types where attrition is of special relevance, namely fluidized beds and pneumatic conveying lines. The problems caused by attrition can be divided into two broad categories. On the one hand, there is the generation of fines. In the case of fluidized bed catalytic reactors, this will lead to a loss of valuable catalyst material. Moreover, attrition may cause dust problems like explosion hazards or additional burden on the filtration systems. On the other hand, attrition causes changes in physical properties of the material such as particle size distribution or surface area. This can result in a reduction of product quality or in difficulties with operation of the plant. 

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