Gas-liquid flow patterns

Quandt, E., Analysis of Gas-Liquid Flow Patterns, A.I.Ch.E., 6th Nat l Heat Transfer Conference, Boston, Mass., Aug. 1963. 

However, in contrast to the two classes of dispersive mixers mentioned before, the attached flow-through channel contains a packed bed of particles which may carry a catalyst. This chamber is much larger than the typical dimensions of the inlet channels (e.g. compare with Section 5.1.2). The packed bed and its interstices influence the gas/liquid flow patterns, e.g. a trickle-bed operation may be established. 

The problem of two-phase-flow classification is complicated by the inevitable differences due to individual interpretations of visual observations, and also by differences in terminology. Fig. 1, taken from the work of Govier et al. (G6), shows the variation in terminology used for vertical gas-liquid flow patterns. It includes a classification of flow regimes proposed by Govier et al. based on pressure-drop behavior rather than visual observations, as illustrated in Fig. 2. In the definitions adopted by the writer, which follow, an attempt has been made to select the most... 

Well-Mixed Bubble Column Reactors Gas-Liquid Flow Patterns and Mass Transfer... 

Figure 6 Gas-liquid flow patterns in horizontal flow.

FIG. 6-24 Gas/liquid flow patterns in horizontal pipes. (From Alves, Chem. Eng. Progr., 50, 449 56 [1954].)... 

For example, in one version of the Wacker process used for the oxidation of ethylene to acetaldehyde with soluble palladium-copper complexes, a tubular reactor containing ceramic rings is used to promote gas-liquid contacting and to impart a gas-liquid flow pattern that approaches ideal tubular reactor behavior. 

Taylor flow is a type of gas-liquid flow pattern that consists of elongated bubbles with equivalent diameter usually many times that of the channel diameter, separated by liquid slugs (Fig. 1). The bubbles adopt a characteristic capsular shape and can either completely or nearly completely fill the channel cross section where at most a thin liquid film separates them from the channel wall. 

As the dimensions of the channel reduce, Taylor and annular flows dominate, while patterns specific to small channels appear (such as ring, liquid lump, Yakitori and rivulet flows). These can be considered to be variations of the Taylor and annular regimes. For a review of gas-liquid flow patterns in microchannels see Ghiaasiaan and Abdel-Khalik [2]. 

Figure 5.45 shows the representative gas-liquid flow patterns observed in capillary channels. Broadly, five different flow patterns are observed which can be classified as follows ... 

Figure 5.45 Schematic showing various gas-liquid flow patterns observed in capillary channels (a) film flow, (b) bubbly flow, (c) segmented flow (Taylor flow), (d) chum flow, and (e) annular flow...

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