Flow gravity based separation

Figure 7.17 Schematics of different types of flow splitters for separation of liquid-liquid two-phase flow, (a) Geometrical modifications (e.g., Y-separator), (b) wettability based (e.g., membrane separator), and (c) gravity based separator (e.g., settler).

Often microstructured reactors are used for high flow velocities where the inertial forces dominate the surface forces. In this case, a separation principle identical to conventional equipment is used. The gravity based separation, based on the density difference between two phases, is the most commonly used method of separation. 

Lead Plant digests Carbon tetrachloride UV—Vis 12 pg L-1 Multi-commuted flow system air as carrier stream dithizone (the complexant agent) in the organic phase gravity-based phase separation [469]... 

Heterogeneous hydrogenation catalysts can be used in either a supported or an unsupported form. The most common supports are based on alurnina, carbon, and siUca. Supports are usually used with the more expensive metals and serve several purposes. Most importandy, they increase the efficiency of the catalyst based on the weight of metal used and they aid in the recovery of the catalyst, both of which help to keep costs low. When supported catalysts are employed, they can be used as a fixed bed or as a slurry (Uquid phase) or a fluidized bed (vapor phase). In a fixed-bed process, the amine or amine solution flows over the immobile catalyst. This eliminates the need for an elaborate catalyst recovery system and minimizes catalyst loss. When a slurry or fluidized bed is used, the catalyst must be separated from the amine by gravity (settling), filtration, or other means. 

Vapor-Liquid Gravity Separator Design Fundamentals The critical factors in the performance of a horizontal separator are the vapor residence time and the settling rate of the liquid droplets. However, two other factors enter into the design—the vapor velocity must be limited to avoid liquid entrainment, and there must be sufficient freeboard within the vessel to allow for a feed distributor. For vertical separators, the design is based on a vapor velocity that must be less than the settling velocity of the smallest droplet that is to be collected, with due allowance for turbulence and maldistribution of the feed. The vapor residence time is a function of the vapor flow rate (mass), vapor density, and volume of vapor space in the separator, based on the following ... 

Fig. 2 Determination of IgE using aptamer-based APCE. (A) Electropherograms obtained for 500 nM of A with 0 (left) and 500 nM (right) IgE. Migration buffer was 10 mM phosphate at pH 7.4, and 10 nM fluorescein was used as internal standard (IS). Injector-to-detector length was 20 cm. (B) Separation of same solutions in 10 mM phosphate at pH 8.2 and gravity-induced flow of 0.02 cm/s. (C) Solutions of 300 nM of A with no IgE (left), 300 nM IgE (middle), and 1 nM IgE (right) were separated with injector-to-detector length of 7 cm. After 48 s of separation, a vacuum was applied to the outlet to rapidly pull the complex to the detector. 4(5)-Carboxyfluorescein (5 nM) was used as internal standard. Fluorescent signal scale for the 1 nM IgE sample is expanded by 10-fold relative to the other electropherograms. (From Ref. 26.)...

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