Two-phase stream

The inlet section is designed to separate out most of the liquid phase such as large slugs or droplets in a two phase stream. These simple devices redirect the inlet flow... 

Horizontal Blowdown Drum/Catch Tank This type of drum, shown in Fig. 26-16, combines both the vapor-liquid separation and holdup functions in one vessel. Horizontal drums are commonly used where space is plentiful, such as in petroleum refineries and petrochemical plants. The two-phase mixture usually enters at one end and the vapor exits at the other end. For two-phase streams with very high vapor flow rates, inlets may be provided at each end, with the vapor outlet at the center of the drum, thus minimizing vapor velocities at the inlet and aiding vapor-hquid separation. 

Turndown scenarios using a two-phase stream are also investigated with the model. FCCU catalyst fines are represented by salt granules or silica beads. The model is used to evaluate the rate of particulate accumulation due to turndown conditions. An SCR unit should recover and return the settled catalyst that collects on straight run ducting and horizontal transitions back into the flowing stream. 

One further vapor/liquid equilibrium problem is the flash calculation. origin of the name is in the change that occurs when a liquid under press passes through a valve to a pressure low enough that some of the liquid vapori or flashes, producing a two-phase stream of vapor and liquid in equilibri We consider here only the P.f -flash, which refers to any calculation of quantities and compositions of the vapor and liquid phases making up a two-ph system in equilibrium at known P, T, and overall composition. 

Meltser, V.L. and Pisarik, N.K. 1980. Interphase heat transfer in impinging single and two-phase streams. Proceedings of the XI All Russian Conference on Heat and Mass Transfer, 6(1) 132-135 (in Russian). 

The balances of a component transferred in a countercurrent flow of two-phase streams have already been presented in the section on absorption. As a rule the sohd adsorbent phase is moving downward in countercurrent movement to the fluid phase (moving bed). 

Droplets and bubbles in microchannels are very stable, in particular when surfactants are added. As a result, one should focus on the conditions at the inlet of the channel. Once formed, droplets and bubbles of a given size often remain intact when carefully expanded within a microchannel network. As is shown in Figure 1.5, a two-phase stream that was generated as a segmented flow may well become a bubbly or foam-like flow. 

The PCHE is capable of being used at temperatures within the range -200°C to 900°C. Pressure differentials in excess of 600 bar can be accommodated. The design is particularly versatile in terms of the number of passes and number of streams which can be built into a PCHE block, and the type can be used for a wide variety of duties involving single-phase liquids and gases or two-phase streams. PCHEs are typically four to six times smaller and lighter than shell and... 

In the Heatric process, the warm wet pressurised gas from the inlet separator is pre-cooled in the PCHE and then throttled in a Joule-Thomson (JT) valve to a lower pressure. The drop in pressure produces a cooling effect and both hydrocarbon liquids and water condense out of the gas. The two-phase stream passes to a separator where the liquids are removed. The cold dry gas from the separator is returned to the exchanger to chill the incoming warm, wet gas (Figure 9.3). Refrigeration... 

For a two-phase stream essential effect on aerodynamic formation of a stream magnitude of relative loading on a liquid L = UG renders, kilograms per kilogram. Thus L practically does not influence distribution axial, but considerably reduces an average value of tangential speeds. The form of profiles =f(R) thus remains identical (Mustashkin, 1970 and... 

Mustashkin, F. A Two-Phase Streams. Kazan Works KCTU 1970, 45, 94-99, (in Russian). 

Intensive researches of hydrodyTiamics direct-flow and parallel flow-vortical, one-and two-phase streams as such streams are widely used and in other branches of techniques technical equipment are carried out. The saved up saved theoretical and experimental material allows verification to count the basic hydrodynamical parameters of vortical devices. But the hydrodynamics is insufficiently studied investigated at the raised increased and average pressure, i.e., in one of preferable areas of use of vortical devices. 

This practice applies only to single phase gas mixtures that vary in composition. A representative sample cannot be obtained from a two-phase stream. 

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