Velocity brine

The surfactant retention tests were performed in the porous medium at 43° C in sandpack (Sor = 0) saturated with brine (See composition in Table I). The injection flow rate used in these tests (2 cm3/h) corresponds to a front velocity of 30 to 40 cm/day. 

The Effect of Surfactant Concentrations, The effect of surfactant concentrations on CC -foam mobility is plotted on a log-log scale in Figure 3. The presented data points are the average mobility values obtained from a superficial velocity range of 2-10 ft/day, with the CC -foam fraction was kept constant around 80%. With Berea sandstone, ZS and AEGS surfactants were used. The measured average permeability of the Berea sandstone with 1% brine was 305 md. With Baker dolomite, AEGS was used to make comparison with Berea sandstone. The permeability of the Baker dolomite was 6.09 md measured with 1% brine solution. 

By definition, the anion-free water is free of salt. When pressure is applied to a clay-brine slurry to force out water (as that described in the experimental section), the solution that flows out of the cell should maintain the same chloride concentration as the brine s if the anion-free water is immobile. Otherwise, the concentration of the chloride decreases. Pressure forces water to flow through the pores with a certain velocity meanwhile, the pore size... 

The trials, which were carried out in 1997 and 1998, have provided the data and understanding of the relationships between permeate flow and inlet brine velocity for different operating pressures. The graph in Fig. 11.4 shows that the brine permeability, when kept at constant inlet velocity through a standard membrane, is quite predictable for a known concentration of sulphate in the brine. The upper and lower... 

The feed brine of the DEP contains a large quantity of carbonates. Therefore, at pH5 carbon dioxide is degassed. When hypochlorite is added, chlorate and bromate are formed in the feed of the electrolysis cells. These reactions have a slow velocity. The result of this is that conversion is only partial ... 

Increasing the velocity of flow of the liquor through tubes results in a significant increase in the liquid-film transfer coefficient. This is achieved in the forced circulation units where a propeller or other impeller is mounted in the central downcomer, or a circulating pump is mounted outside the evaporator body. In the concentration of strong brines, for example, an internal impeller, often a turbine impeller, is fitted in the downtake, and this form... 

Figure 19.16. Basic designs of electrolytic cells, (a) Basic type of two-compartment cell used when mixing of anolyte and catholyte is to be minimized the partition may be a porous diaphragm or an ion exchange membrane that allows only selected ions to pass, (b) Mercury cell for brine electrolysis. The released Na dissolves in the Hg and is withdrawn to another zone where it forms salt-free NaOH with water, (c) Monopolar electrical connections each cell is connected separately to the power supply so they are in parallel at low voltage, (d) Bipolar electrical connections 50 or more cells may be series and may require supply at several hundred volts, (e) Bipolar-connected cells for the Monsanto adiponitrile process. Spacings between electrodes and membrane are 0.8-3.2 mm. (f) New type of cell for the Monsanto adiponitrile process, without partitions the stack consists of 50-200 steel plates with 0.0-0.2 ram coating of Cd. Electrolyte velocity of l-2 m/sec sweeps out generated Oz.

In the 300-gallon-per-day plant the mean ice particle sizes have been calculated from measurements of ice bed permeability and porosity made on the ice harvested at the top of the column. From these results the important design parameters can be calculated, such as particle diameters, linear ice velocities, residence time of ice in the column, frictional losses in the wash water flowing down the column and in brine flowing toward the screens in the bottom of the coltam, and the fraction of voids occupied by air above the liquid level in the column. Typical ranges for some of these measured or calculated quantities are shown in Table III from measurements in the 12-inch diameter column. 

Results are shown graphically in Figure 4 for a brine temperature of 220°F., condenser tube velocity of 5 feet per second, blowdown temperature of 90°F., and brine concentration of twice sea water. As can be seen, a minimum water cost for these conditions is obtained with a 50-stage plant operating with a terminal temperature difference of about 4°F. Similar calculations were made for a blowdown concentration of 1.5 times sea water and for a once-through system. By cross plotting, it was then possible to determine the optimum blowdown salt concentration for the plant. It was about 1.7 times sea water. However, the curve is almost flat in the range of 1.5 to 2.0 times sea water. 

Brine Staging Velocity past the membrane is important. If too low, polarization is excessive, local O rises, and rejection declines. Fouling occurs faster. If too high, pressure losses are higher than they need be, and the osmotic pinch is premature. Since the volume of feed declines continuously, the hydraulic design needs periodic rearrangement. This is commonly done as shown in Fig. 22-64, sometimes known as a Christmas tree. This design is commonly used where the fluid is pumped once, as in RO, NF, and gas-separation systems, but not where recirculation is practiced, as in ultrafiltration. 

Droplet size depends on a number of factors such as the type of oil, brine composition, interfacial properties of the oil-water system, surface-active agents present (added or naturally occurring), flow velocity, and nature of porous material. For the study of OAV emulsions, McAuliffe (9) varied emulsion droplet sizes and size distributions by increasing the sodium hydroxide concentration in the aqueous phase, as shown in Figure 10. Higher NaOH concentration neutralizes more of the surface-active acids in the crude oil and produces an emulsion that has droplets of smaller diameters and is also more stable. Emulsion droplet size distribution can also be varied by varying the concentration of a surfactant added to the crude oil, as shown in Figure 11. 

The increased relative velocities of the microemulsion-oil interfaces at these conditions (as evidenced in Table II) indicate that the microemulsion contained a significant amount of oil. As a result, the microemulsion was probably a middle phase. This conclusion is supported by the formation of the brine phase, which exists in equilibrium with this type of microemulsion at these conditions. 

Figure 8 shows the microemulsion interface positions for the PDM system in this regime. Convection is not indicated. The dispersion front boundaries were very irregular in shape, and, therefore, those positions are not plotted. However, estimates of the relative dispersion front velocity in each experiment are given in the first two entries of Table III. As is evident from the small difference between these values and those for the brine interface, the brine layer grew very slowly at these salinities. 

An extended experiment was performed for the 2.0 gm/dl-salinity Pm system to determine the effect on relative interface velocities of the formation of myelinic figures and the C phase. With reference to Figure. 18, the formation of a uniform layer of C phase at t1 = 12 hr1 (6 days) corresponds to a decrease in relative velocity of the brine-microemulsion interface. The layer of C phase grew uniformly after its initial formation. In Figure 18, all positions are plotted relative to the same reference position. The offset of the liquid crystal interface at t = 0 indicates brine formation due to initial mixing. 

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