Flow pattern diagrams

Figure 3.2 Flow pattern diagram for horizontal flow. (From Scott, 1963. Copyright 1963 by Academic Press, New York. Reprinted with permission.)...

Recommendations At present, the best available flow-pattern diagrams for nonfoaming and foaming liquids are the ones shown in Fig. 6-3 and their use is recommended when the experimental data are not available. However, in the light of the results of Chou et al., 6 wherever possible the flow regimes should be determined experimentally. Better theoretical understanding of the transition from one flow regime to other is needed. 

Fig. 17. Flow pattern diagrams in gas-liquid downward flow in packed beds (C12). (a) Nonfoamable liquid, (b) foamable liquid.

Unfortunately most other authors have not given pressure drop data to match their interfacial area data. To use flow pattern diagrams (C13, B12, S6, Cl2) and to calculate pressure drop from energy relationships (see Section IV,A,3,a) Charpentier (CIO) has shown that Eq. (113) fits the experimental results for other packing shapes and sizes (Fig. 19) for both pulse flow and spray flow. 

Fig. 4.47 Flow pattern diagram for vertical, two-phase flow according to Hewitt and Roberts [4.81]...

Figure 8.17 Flow pattern diagram for liquid—liquid flows in microfabricated systems with transition lines from different literature data. From [2].

In the case of higher gas flow rates, the flow pattern may become annular, for horizontal pipes, where a continuous liquid film (which varies in thickness around the circumference of the pipe) exists over the full pipe circumference, whilst gas flows in the middle of the pipe. Since the steel surface is completely wetted, corrosion is equally fikely to occur at any point around the circumference. When using flow pattern diagrams, the superficial velocity may be defined as the velocity the (liquid/gas) phase would exhibit if it flowed through the total cross section of the pipe alone. 

Radial-flow impellers include the flat-blade disc turbine, Fig. 18-4, which is labeled an RlOO. This generates a radial flow pattern at all Reynolds numbers. Figure 18-17 is the diagram of Reynolds num-ber/power number curve, which allows one to calculate the power knowing the speed and diameter of the impeller. The impeller shown in Fig. 18-4 typically gives high shear rates and relatively low pumping capacity. 

Figure 4.22 Schematic diagram of hydrocyclones, a) Flow pattern, (h) Alternate a.spect ratios adapted for service after Wallas, 1988)...

Mixing concepts, fundamentals, 297 Actual motor horsepower, 307 Axial flow, 291 Baffle diagrams, 318 Baffles, 311 Calculations, 297 Characteristic curves, 306 Draft lubes, 309, 312, 313 Entrainment, 309 Flow number, 298 Flow patterns, 309-313 Flow, 298... 

To evaluate the true temperature difference (driving force) in a mixed vapour condenser a condensation curve (temperature vs. enthalpy diagram) must be calculated showing the change in vapour temperature versus heat transferred throughout the condenser, Figure 12.48. The temperature profile will depend on the liquid-flow pattern in the condenser. There are two limiting conditions of condensate-vapour flow ... 

You have available in your pilot plant a small recycle reactor whose flow pattern may be represented schematically by the following diagram. 

Fig. 8.5 Schematic diagram of internal and external flow patterns for a skirted bubble or drop.

Detailed kinematic investigations of flow near the front of a stream were undertaken.284 A diagram of the experimental device is shown in Fig. 4.49. In the experimental procedure, a liquid was placed in a chamber with transparent walls above an aluminum piston, which was driven downwards by connection to a suitable drive. This resulted in the appearance of streams inside the liquid,and three different flow zones could be distinguished. The so-called "fountain effect discussed in Section 2.11 appeared near the free surface, while a reverse fountain flow was observed below the moving surface. It is interesting to note the movement of two liquids with different densities, when one liquid is used as a piston to push the other (analyzed experimentally and theoretically).285 If the boundary between the two liquids is stationary and the walls of the chamber move at constant velocity, then the pattern of flow is as shown in Fig. 4.50, where flow trajectories corresponding to front and reverse fountain effects are clearly shown. Two other flow patterns -developed flow inside the main part of the chamber and circulation near the surface of the aluminum piston - were also observed. 

FIGURE 4.15 Schematic diagram of flow pattern for a gated injector. CCD images of the gated injection using rhodamine B (b) prior to injection, (c) during injection, and (d) after injection into separation column with E = 200 V/cm [317]. Reprinted with permission from the American Chemical Society. 

Fluid-particle flow patterns are often clarified by application of phase diagrams. Kwauk (1963) and Matsen (1983) proposed such phase diagrams for moving beds. 

Figure 6-2 A summary of published diagrams for flow-pattern boundary (utter Satn et ul.lr y...

Figure 11.5 Schematic diagram of three different flow patterns of feed and permeate/purge streams used for comparison in Table 11.1 [Zaspalis et al.. 1991a)...

Scheme 1. The electron flow pattern between the electron donors (succinate and NADH) and the electron acceptor (oxygen) in the mitochondrial respiratory ETS. The diagram shows the organization of the ETS into...

As the different flow regimes are determined by the forces between the two phases, above all by the inertia and gravitational forces, it is appropriate to mark the dependence of the boundaries between the different flow patterns on these forces in diagrams, so-called flow maps. This type of flow map was first presented by Baker [4.80]. Therefore, we also speak of Baker-diagrams. These diagrams only provide a rough orientation because the decisive forces in the different flow regions are not known with sufficient certainty. In particular, for a two-phase flow with... 

Figure 5.3 Schematic diagram showing the flow pattern in a small region of a column. Reprinted with permission from f.C. Giddings, "Dynamics of Chromatography" (Figure 2.9- -1), by courtesy of Marcel Dekker Inc.

Figure 1 Diagram of the cryocycler designed to automatically subject microbial cultures to freeze-thaw cycles. Grey lines show the flow pattern in the power-off state with the valves in position to circulate ethylene glycol at -18"C through the jacketed sample chamber. Dotted lines show the partial 5"C flow pattern during the power-on state.

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