Pipes design

J. E. Kemme, Heat Pipe Design Considerations, T-4221 -MS, Los Alamos Scientific Laboratory, University of California, Los Alamos, N.M., 1969. 

Heat Pipe Design Handbook, Dynatherm Corp., CockeysviUe, Md., 1972. 

Often, the pressure drop required for design flow rate is unacceptably large for a distributor pipe designed for uniform velocity through uniformly sized and spaced orifices. Several measures may be taken in such situations. These include the following ... 

Modern-day piping design codes can model the vibration situation, and problems can thus be resolved in the design phases. 

Uneven wear in parts is often due to turbulence. Bad piping designs or poorly sized valves can cause turbulence and uneven wear in pumps. Whenever possible, use straight pipe sections before and after the pump. Uneven flow creates turbulent flow and excessive wear occurs. 

Drain pipe design must respect proper submergence (Figure 17-3). The. submergence laws appear later in this chapter. 

This is an important part of the pump system and should be thought of as a very speeialized piping design. Considerable attention must be direeted to the pump suetion piping to ensure satisfactory pump operation. 

Kern, Robert, C. E. Refresher—Piping Design for Two-Phase Flow, C/ em, Engr., June 23, 1975, p. 145. Simpson, L. L., Sizing Piping for Process Plants, Chem. Engr., June 17, 1968, p. 192 (Vertical downflow example p. 203). 

The lift pipe design was tapered to a larger diameter at the top. This minimized the effects of erosion and catalyst attrition, and also prevented the instantaneous total collapse of circulations when the saltation concentration, or velocity, of solids is experienced (i.e. the slump veloeity-that velocity helow which particles drop out of the flowing gas stream). In a typical operation, 2 % to 4 % eoke can he deposited on the catalyst in the reactor and burned in the regenerator. Catalyst circulation is generally not sufficient to remove all the heat of eombustion. This facilitated the need for steam or pressurized water coils to be located in the regeneration zone to remove exeess heat. 

Figure 4.4. (a) Improper use of a flexible connection to compensate for poor piping alignment. (b) Proper piping design and alignment. 

J. M. Whitney, N. J. Pagano, and R. B. Pipes, Design and Fabrication of Tubuiar Specimens for Composite Characterization, in Composite Materials Testing and Design (Second Conference), H. T. Corten (Chairman), Anaheim, Caiifomia, 20-22 April 1971, ASTM STP 497, American Society for Testing and Materials, 1972, pp. 52-67. 

Compressible fluid flow occurs between the two extremes of isothermal and adiabatic conditions. For adiabatic flow the temperature decreases (normally) for decreases in pressure, and the condition is represented by p V (k) = constant. Adiabatic flow is often assumed in short and well-insulated pipe, supporting the assumption that no heat is transferred to or from the pipe contents, except for the small heat generated by fricdon during flow. Isothermal pVa = constant temperature, and is the mechanism usually (not always) assumed for most process piping design. This is in reality close to actual conditions for many process and utility service applications. 

Kern, Robert, Piping Design For Two-Phase Flow, Chem. Eng., June 23, 1975, p. 145. 

Dukler, A. E. and Taitel, Y, Flow Patterns in Horizontal and Near Florizontal Pipes, Design Manual FM-3, DIMP/AIChE, New York, 1982 also see Design Manual WFP/AlChE, same reference. 

To improve the efficiency of collection, several units can be installed in series. The plate type unit is the most common design for dry dust removal, while pipe design is mainly for removal of liquid or sludge particles and volatilized fumes. The plates/pipes are the collecting electrodes, with the discharge electrodes suspended between the plates or suspended in the pipes [41,53,57],... 

Tabulated below are the most generally required data used in piping design. This table is believed to be the most conii)rehensive published uj) to this time. Many thicknesses traditionally included in such tables have been omitted because of their having become obsolete through disuse and lack of coverage by any Standard. 

The control of acoustic resonances should always he considered in piping design. That is, acoustic resonant frequencies of piping elements should he separated from the frequencies of prominent engine harmonics as much as pos-... 

---