Liquid split ratio

Thus, it is more suitable to define the flows of the thermally coupled parts of the column in terms of a liquid split ratio, O/,. For the side stripping unit, we define a liquid split ratio as... 

Both these split ratios govern the amount of material sent to the side column and are bound between 0 and 1. Thus, for the side stripper, the refluxes of all the remaining CSs can be determined by specifying the reflux of the topmost CS (/ ai)> and its associated liquid split ratio, as shown in Equations 6.13 6.15... 

Liquid Split Ratio. Adjusting the <1> value automatically updates the R s for the entire column. When the TT method is selected in (c), the textbox is disabled. If the profile intersection method is selected in (c), the user is required to specify a positive, scalar value in the > textbox that is greater than zero and less than 1. 

In addition, there are four degrees of freedom that are adjustable during design and are also adjustable during operation of the column reflux flow rate (/ ), vapor boilup (V), sidestream flow rate (5), and the liquid split ratio (jSl = i-p/i-R)- The variable Lp is the liquid flow rate fed to the prefractionator side of the wall, and Lp is the total liquid leaving the bottom tray in the rectifying section. Of course, the rest of the liquid coming from the bottom of the rectification section is fed to the sidestream side of the column. Distillate and bottoms flow rates are used to maintain liquid levels in the reflux drum and column base, respectively. 

The fourth control loop in the proposed control structure is one in which the concentration of the heaviest component xylene at the top of the prefractionator is controlled. As discussed earlier, the main function of the prefractionator is to keep xylene from going out the top of the wall. Any xylene that does get up this far must be rejected in the rectifying section, and this means that xylene is present in the liquid flowing down into the sidestream side of the wall. The liquid split ratio is 0.353, so 65.7% of the liquid from the rectifying section enters the sidestream side of the waU. The concentration of the xylene will be higher in the liquid phase than in the vapor phase. Since a liquid sidestream is being withdrawn, the xylene impurity will show up in the sidestream product. Therefore, it is vital to prevent xylene from getting to the top of the wall in the prefractionator. 

It should be emphasized that the liquid split ratio does not change for feed flow rate changes, but Figure 12.20 clearly shows that it should change for feed composition changes if energy is to be minimized. 

Figure 12.20 (a) Effect of liquid split ratio on energy consumption and prefractionator vapor composition for changes in benzene feed composition, (b) Effect of liquid split ratio on energy consumption and prefractionator vapor composition for changes in toluene feed composition, (c) Effect of Uquid split ratio on energy consumption and prefractionator vapor composition for changes in xylene feed composition. 

Figure 12.22 SFC-GC analysis of aromatic fraction of a gasoline fuel, (a) SFC trace (b) GC ttace of the aromatic cut. SFC conditions four columns (4.6 mm i.d.) in series (silica, silver-loaded silica, cation-exchange silica, amino-silica) 50 °C 2850 psi CO2 mobile phase at 2.5 niL/min FID detection. GC conditions methyl silicone column (50 m X 0.2 mm i.d.) injector split ratio, 80 1 injector temperature, 250 °C earner gas helium temperature programmed, — 50 °C (8 min) to 320 °C at a rate of 5 °C/min FID detection. Reprinted from Journal of Liquid Chromatography, 5, P. A. Peaden and M. L. Lee, Supercritical fluid chromatography methods and principles , pp. 179-221, 1987, by courtesy of Marcel Dekker Inc.

Hot split Sample (usually liquid) passes from syringe into hot inlet rapid vaporisation initial oven temperature not critical small fraction allowed to column (split ratios 1 20 to 1 400) Concentrated samples Narrow 0.1-2 0.01-10... 

Split vent. The sample vapors that do not enter the column are ejected through the split vent. A needle valve on this line regulates the total flow of carrier gas into and from the inlet, generating the split ratio, which determines the portion of sample that enters the column. The split ratio is the ratio of the split vent flow to the column flow and provides a measure of the amount of sample that actually enters the column from the injection. A split ratio of 100 1 indicates that a lpl injection from the syringe results in approximately 10 ml of liquid sample reaching the column. 

One of the key thermodynamic parameter in heterogeneous batch distillation is the decanter split ratio liquid-liquid tie line at the decanter temperature or alternatively by the mole ratio of the entrainer-rich phase ZR to the overall liquid phase Z° into the decanter as follows ... 

As stated by Rodriguez-Donis et al. [6], the reflux policy to be used is strongly influenced by the split ratio liquid reflux needed at the top of the column is lower than Zr, then the distillation can be performed by using only the reflux of entrainer-rich phase. Otherwise, the separation of original components requires the reflux of a combination of both decanted phases. 

In a l-l. three-necked flask equipped with a dropping funnel, a thermometer, and an efiicient fractionation column fitted with either a vapor- or liquid-splitting head (Note 1) is placed 400 ml. of mineral oil. The oil is heated to 240-270 and dicyclopen-tadiene (Note 2) is added at the rate of 5-10 ml. per minute. The reflux ratio and the rate of addition of dicyclopentadiene are adjusted to maintain the distillation head temperature at 40°. The cyclopentadiene is collected in a Dry Ice-acetone receiver (Note 3). 

Endothelial cells cultured on 35-mm-diameter gelatine-coated dish are harvested at confluence and seeded onto 60-mm-diameter gelatine-coated dishes. After 6-8 days, confluent cells are subcultured at the split ratio 1 15. Cells at the third passage can be stored in liquid nitrogen. Frozen at passage 3, brain capillary endothelial cells are re-cultured on 60-mm-diameter gelatine-coated dishes and trypsinized at confluence before seeding on filters. 

Restrictor flow is temperature, pressure, and composition dependent, which means that there is a variable, but predictable, split ratio to the MS. A reagent liquid (usually extra methanol) is added with a makeup pump through another tee. This extra methanol flow tends to stabilize the split ratio. 

Liquid draw splitter SP2, splitter 1, split ratio... 

The total condenser consists of a stage with heat rejection, and a splitter that splits the condensed vapor into a reflux and a liquid product. The stage heat rejection rate is one degree of freedom, and the splitter split ratio is another. Hence, a total condenser adds two degrees of freedom to the column. 

The partial condenser with vapor and liquid products is represented by an equilibrium stage and a splitter, each of these units having one degree of freedom The heat rejected at the equilibrium stage and the splitter split ratio. This type condenser also adds two degrees of freedom to the column. 

Gas-liquid chromatography (GLC) was used routinely to monitor reactions, in a Carlo Erba HRGC 5160 chromatograph, with a FID detector and a silicone DB-1 (bonded methyl silicone, J W Scientific, Inc., Rancho Cordova, California column, 15 m x 0,25 mm x 0,10 pm. Helium N50 was used as carrier (2 ml/min, 60 KPa, split ratio 100 1) and analyses were performed at 260°C (iiy.) oven, 170°C (7 min) 200°C (2 min, 4 C/min) 285°C (15°C/min 20 min). Melting points were determined on a Reichert Thermovar hot bench and are uncorrected. Infra-red spectra were recorded on a Perkin-Elmer 298, as liquid films in CHCI3 solution. Proton and... 

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