Free liquid

Barium is a metallic element, soft, and when pure is silvery white like lead it belongs to the alkaline earth group, resembling calcium chemically. The metal oxidizes very easily and should be kept under petroleum or other suitable oxygen-free liquids to exclude air. It is decomposed by water or alcohol. 

Figure 3.10 is a plot of potential against distance from the wall for a liquid in a capillary of sufficient width for its middle A to be outside the range of forces from the wall. Since the capillary condensate is in equilibrium with the vapour, its chemical potential (=p represented by the horizontal line GF, will be lower than that of the free liquid the difference in chemical potential of the condensate at A, represented by the vertical distance AF, is brought about entirely by the pressure drop, Ap = 2y/r , across the meniscus (cf. Equation (3.6)) but at some point B. say, nearer the wall, the chemical potential receives a contribution represented by the line BC, from the adsorption potential. Consequently, the reduction Ap in pressure across the meniscus must be less at B than at A, so that again... 

Fig. 3.10 Contributions to the lowering of chemical potential of the condensed liquid in a capillary, arising from adsorption forces (c) and meniscus curvature (Ap). The chemical potential of the free liquid is , and that of the capillary condensed liquid is (= ) z is the distance from the capillary wall. (After Everett. )...

In vacuum drying or other processes containing atmospheres of 100 percent vapor, the temperature of liquid vaporization will equal or exceed the saturation temperature of the liquid at the system pressure. (When a free liquid or wetted surface is present, drying will occur at the saturation temperature, just as free water at I0I.325 kPa vaporizes in a 100 percent steam atmosphere at I00°C.)... 

If the cake is washed with solnte-free liquid, percent remaining is readily calculated by dividing the solute concentration in the hqnid remaining in the washed cake by the solute concentration in the liquid in the original feed. 

The details of the mathematical model of these four components are given below. Drainage of free liquid in thin film ... 

A dense-bed center-fed column (Fig. 22-li) having provision for internal crystal formation and variable reflux was tested by Moyers et al. (op. cit.). In the theoretical development (ibid.) a nonadiabatic, plug-flow axial-dispersion model was employed to describe the performance of the entire column. Terms describing interphase transport of impurity between adhering and free liquid are not considered. 

Noncontainerized hazardous wastes containing free liquids, whether or not adsorbents have been added. 

A. Berthold (Ed.), Countercurrent Chromatography (CCC). The Support-Free Liquid Stationary Phase, Elsevier, Amsterdam, 2002. ISBN 044450737X. 

Remove Free Liquids and Highly Mobile Wastes Stabilize/Repair Side Walls. Dikes or Liner(s)... 

Often, the immobilized product has a structural strength sufficient to prevent fracturing over time. Solidification accomplishes the objective by changing a non-solid waste material into a solid, monolithic structure that ideally will not permit liquids to percolate into or leach materials out of the mass. Stabilization, on the other hand, binds the hazardous constituents into an insoluble matrix or changes the hazardous constituent to an insoluble form. Other objectives of solidiflcation/stabilization processes are to improve handling of the waste and pri uce a stable solid (no free liquid) for subsequent use as a construction material or for landfilling. 

We need to keep in mind the disposal costs in all of the mechanisms for solidification. With the first method, keep in mind that free liquids are typically not allowed in most disposal scenarios. And adding too much adsorbent can substantially add to disposal costs. Make this point clear to your field people. As far as using polymerization catalysts and chemical reagents, keep in mind disposal costs. Ensure that you are cognizant of disposal costs of spent catalyst prior to using this scenario. As far as freezing is concerned, consider the cost to keep the contaminants frozen and what the downsides are. The downsides besides cost include measures in case of power failure and use of freezing equipment after wastes have been disposed. 

In the drying cycle, the wet inlet gas first passes through an inlet separator where free liquids, entrained mist, and solid particles are removed. This is a very important part of the system because free liquids can damage or destroy the desiccant bed and solids may plug it. If the adsorption... 

S is the so-called sediment volume. The volume of free liquid is (1 - S). Typically, k = -25, and S = 1.22 for most high-energy propellants. 

In an airlift fermenter, mixing is accomplished without any mechanical agitation. An airlift fermenter is used for tissue culture, because the tissues are shear sensitive and normal mixing is not possible. With the airlift, because the shear levels are significantly lower than in stirred vessels, it is suitable for tissue culture. The gas is sparged only up to the part of the vessel cross section called the riser. Gas is held up, fluid density decreases causing liquid in the riser to move upwards and the bubble-free liquid to circulate through the down-comer. The liquid circulates in airlift reactors as a result of the density difference between riser and down-comer. 

We express the altered concentration in terms of the adsorption excess. If all the adsorbed substance were contained to the extent of k gr. per cm.2 on a superficial layer of zero thickness and surface total mass present in the volume Y would be m = V + kto. The layer of altered concentration must, however, have a certain thickness. We will therefore imagine a plate 2 placed in front of the surface and parallel to it, and define the adsorption excess as the concentration in the included layer minus the concentration in the free liquid. That this result is independent of the arbitrarily chosen thickness is easily proved when we remember that the problem is exactly the same as that of finding the change of concentration around an electrode in the determination of the transport number of an ion by Hittorf s method. 

The layer 8 we shall call the true adsorption thickness the liquid beyond 8, which has almost exactly the original concentration provided a large volume was present at the start and-T is small, we shall call the free liquid. Now suppose a... 

Where a liquid is below the pump, relates to the vertical distance from the center line of a pump down to the free liquid source. 

In 1944, Foust et al. (F2) studied air holdup in water in baffled vessels agitated with a special impeller developed for gas dispersion. The impeller consisted of arrowhead-shaped blades mounted on a flat disk. The gas holdup was determined by measuring the liquid level before the air was introduced and while the air was fed at a point underneath the impeller. They found that the gas holdup ranged from 2% to 10% of the air-free-liquid volume. 

Gal-Or and Resnick (G8) measured average residence time in a system that was geometrically similar to those used by Cooper et al (C9) and Yoshida et al (Y4) with air-distilled water and air-sodium sulfite solutions of the same concentration as used by these investigators. The ratio of impeller to tank diameter was 0.4 in one series (as in the work of Cooper and Yoshida) and 0.3 in a second series. Gal-Or and Resnick reported their results as an average residence time in seconds per foot of gas-free liquid, Bh. The average residence time was calculated from the equation... 

P Power input to impeller per volume of gas-free liquid... 

Pasoi in. .. F, Proc. Kov. Soc. A 182 (1943) 75. Eva X>ration from a plane free liquid surface into a turbulent air stream. 

State the assumptions made in the penetration theory for the absorption of a pure gas inlo a liquid. The surface of an initially solute-free liquid is suddenly exposed to a soluble gas and the liquid is sufficiently deep for no solute to have time to reach the bottom of the liquid. Starting with Hick s second law ol diffusion obtain an expression for (i) the concentration, and (ii) the muss transfer rate at a time t and a depth v below the surface. 

If applied pressure P is increased from condition 1 to 2, then a(pyjpj) = V (Pi — PSi/RT, where molar volume is V, the gas constant is R and temperature is T. From this, e.g., for water, a 1000-fold increase in P only approximately doubles saturated vapor pressure p. For hydrocarbons, p could be doubled by a lower pressure increase, in the order of 150 times or so however for moderate pressures, a tenfold increase in P even here only increases p by some 5%. Hence, for most practical situations, vapor pressure of a liquid can be considered as independent of applied pressure. Vapor-free liquid may need chemical potential represented differently (possibly by work done). 

In a small-diameter capillary tube, wetting forces produce a distortion of the free liquid surface, which takes a curvature. Across a curved liquid surface, a difference of pressure exists and the variation of pressure across the surface is the Laplace or capillary pressure, given by ... 

Keggin type H3PW)2O40 is a stable, recyclable and effective catalyst for H2S04-free liquid phase nitration of bezene, chlorobenzene and toluene with nitric acid as a nitration agent. Higher para-selectivity of nitrotoluene was obtained, and the result implies that HPA can effectively catalyze the liquid phase nitration of various aromatics as an environmentally friendly nitration process. 

Natural convection can be eliminated entirely when electrolytes held in a matrix or porous support are used instead of free liquids. Natural convection will not develop in a pore space when the individual pores are sufficiently narrow. When such electrolytes are used, the diffusion layer propagates across the entire matrix (i.e., across the full electrode gap). 

Influence on Electrolyte Conductivity In porous separators the ionic current passes through the liquid electrolyte present in the separator pores. Therefore, the electrolyte s resistance in the pores has to be calculated for known values of porosity of the separator and of conductivity, o, of the free liquid electrolyte. Such a calculation is highly complex in the general case. Consider the very simple model where a separator of thickness d has cylindrical pores of radius r which are parallel and completely electrolyte-filled (Fig. 18.2). Let / be the pore length and N the number of pores (all calculations refer to the unit surface area of the separator). The ratio p = Ud (where P = cos a > 1) characterizes the tilt of the pores and is called the tortuosity factor of the pores. The total pore volume is given by NnrH, the porosity by... 

The dominant mechanism of purification for column crystallization of solid-solution systems is recrystallization. The rate of mass transfer resulting from recrystallization is related to the concentrations of the solid phase and free liquid which are in intimate contact. A model based on height-of-transfer-unit (HTU) concepts representing the composition profile in the purification section for the high-melting component of a binary solid-solution system has been reported by Powers et al. (in Zief and Wilcox, op. cit., p. 363) for total-reflux operation. Typical data for the purification of a solid-solution system, azobenzene-stilbene, are shown in Fig. 20-10. The column crystallizer was operated at total reflux. The solid line through the data was com-putecfby Powers et al. (op. cit., p. 364) by using an experimental HTU value of 3.3 cm. 

Fig. 4.18 represents a countercurrent-flow, packed gas absorption column, in which the absorption of solute is accompanied by the evolution of heat. In order to treat the case of concentrated gas and liquid streams, in which the total flow rates of both gas and liquid vary throughout the column, the solute concentrations in the gas and liquid are defined in terms of mole ratio units and related to the molar flow rates of solute free gas and liquid respectively, as discussed previously in Sec. 3.3.2. By convention, the mass transfer rate equation is however expressed in terms of mole fraction units. In Fig. 4.18, Gm is the molar flow of solute free gas (kmol/m s), is the molar flow of solute free liquid (kmol/m s), where both and Gm remain constant throughout the column. Y is the mole ratio of solute in the gas phase (kmol of solute/kmol of solute free gas), X is the mole ratio of solute in the liquid phase (kmol of...

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