Horizontal three-phase separator

TABLE 3—Horizontal three-phase separator diameter vs. length for liquid retention time... 

Coverage has been limited to horizontal three-phase separators up to this point. Considering Fig. 4.9, oil and water must flow vertically downward and gas vertically upward. The same laws of buoyancy and drag force apply. Equation (4.3) may therefore be used in the oil phase for water separation. Equations (4.12), (4.13), and (4.7) (see Fig. 4.8) are applied to the gas phase and oil phase for oil-gas particle separations, as was equally done for horizontal separators. The equations for the horizontal separator from Fig. 4.8 may also be used for the water drop terminal velocity in the vertical separator. 

A typical horizontal three-phase separator with flooded weir is shown in Figure 3.4. The inlet nozzle (Nl) and the gas outlet nozzles (N2) are placed as close as possible to the vessel tangent line. The distance of tiie nozzle center line and the tan line is dictated by tiie mechanical limitations of the vessel however, distances in Table 3.7 can be used for initial design. 

As in two-phase separation, it is also true for three-phase separation that die flow geometry in a horizontal vessel is more favorable from a process standpoint. However, there may be non-process reasons to select a vertical vessel for a specific application. 

Process pressure vessel cost. Process pressure vessels are always designed in accordance with the current ASME code. These major equipment items are always cylindrical metal shells capped with two elliptical heads, one on each end. Installation can be either vertical or horizontal. Vertical is generally a fractionation-type column with internal trays or packing, although the smaller-height vertical vessels (less than 15 ft) are mostly two-phase scrubber separators. The horizontal vessel is generally a two- or three-phase separation vessel. 

There are a number of special variants of the basic horizontal or vertical decanter for simple clarification and dewatering. Special designs are available for three-phase separation, for thickening applications, with a filtration section, for leaching, for washing, and those for operating at extra high temperature and pressure. 

Proper selection of the separator type is important. For three-phase separation, a horizontal separator is more effective than a vertical separator. Also, it is easier to design the control system for a three-phase horizontal separator. 

As the flow rates are quite high and the design needs to accommodate 7 m of slug, a horizontal three-phase flooded-weir separator has been selected. 

The term two-phase flow covers an extremely broad range of situations, and it is possible to address only a small portion of this spectrum in one book, let alone one chapter. Two-phase flow includes any combination of two of the three phases solid, liquid, and gas, i.e., solid-liquid, gas-liquid, solid-gas, or liquid-liquid. Also, if both phases are fluids (combinations of liquid and/or gas), either of the phases may be continuous and the other distributed (e.g., gas in liquid or liquid in gas). Furthermore, the mass ratio of the two phases may be fixed or variable throughout the system. Examples of the former are nonvolatile liquids with solids or noncondensable gases, whereas examples of the latter are flashing liquids, soluble solids in liquids, partly miscible liquids in liquids, etc. In addition, in pipe flows the two phases may be uniformly distributed over the cross section (i.e., homogeneous) or they may be separated, and the conditions under which these states prevail are different for horizontal flow than for vertical flow. 

Fig- 2—Typical configuration of a three-phase horizontal separator. Interface level control maintains water level, weir maintains oil level. Vessels may be equipped with sand jets If sand production is a problem. jets are designed for 20 fps velocity, and produced water normally is used for backwashing. 

Fig. 3—Bucket and weir configuration for three-phase horizontal separator eliminates interface controller and uses conventional displacement fioal lo operate oil and water dump valves This design is useful if paraffin or large volumes o emulsions that would loul interlace controllers are expected.

Fig. 6.3 Schematic phase diagram for lamellar PS-PB diblocks in PS homopolymer (volume fraction 0h). where the homopolymer Mv is comparable to that of the PS block (Jeon and Roe 1994). L is a lamellar phase, I, and I2 are disordered phases, M may correspond to microphase-separated copolymer micelles in a homopolymer matrix. Point A is the order-disorder transition.The horizontal lines BCD and EFG are lines where three phases coexist at a fixed temperature and are lines of peritectic points. The lines BE and EH denote the limit of solubility of the PS in the copolymer as a function of temperature.

Figure 4.4 Three-phase horizontal cylindrical gravity separator.

THREE PHASE HORIZONTAL VESSEL ANALYSIS CALCULATIONS Gas - Oil - Water Separation... 

THREE PHASE HORIZONTAL SEPARATOR DATA INPUT... 

Figure 4.5 Three-phase horizontal separator Vessize program example rims (a) earlier DOS version, and (6) screen display from the current version in Visual Basic format.

Figure 4.6 Cross section of three-phase horizontal separator.

Normally, all three-phase horizontal separators are designed and maintained to be half full of liquid. 

In the absence of special symmetry, the phase mle requires a minimum of three components for a tricritical point to occur. Symmetrical tricritical points do have such s mimetry, but it is easiest to illustrate such phenomena with a true ternary system with the necessary symmetry. A ternary system comprised of a pair of enantiomers (optically active d- and /-isomers) together with a third optically inert substance could satisfy this condition. While liquid-liquid phase separation between enantiomers has not yet been found, ternary phase diagrams like those shown in figure A2.5.30 can be imagined in these diagrams there is a necessary symmetry around a horizontal axis that represents equal amounts of the two enantiomers. 

It is proposed to use an existing horizontal belt filter to separate phosphoric acid from a slurry containing gypsum at 30% w/w. Cake formation at 50 kPa is to be followed by displacement washing and deUquoring phases at the same level of vacuum. The three phases respectively occupy 1.5 m, 4.5 m and 3 m of the 9 m total belt length. The feed suspension and belt filter characteristics are shown in Table 7.2 in addition to other operational parameters. 

Figures 9.4 and 9.5 show G and G" for two linear polymers, a poly(vinyl methyl ether) (PVME) with a molecular weight of 138,000 and a polystyrene (PS) with a molecular weight of 123,000, respectively. The data for each polymer have been moved horizontally along the frequency axis until they form a single curve. There is a substantial region of overlap, extending over three decades of frequency, so the superposition is clearly established. The shift factors needed to obtain overlap of the curves are shown as inserts. The reference temperature for each case was taken to be 84 °C this temperature has no significance other than being a convenient value for the particular application for which the data were obtained, which was a study of phase separation in blends of the two polymers. One of the significant uses of time-temperature superposition is made evident by focusing on the open and closed symbols in the PVME curves. The dynamic moduli are available over five orders...

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