Effect of Liquid Properties

Prince and Blanch used Equation 10.1 to estimate the values of for different electrolytes. In deriving Eqnation 10.1, it was assumed that the interaction between molecules in the liquid film separating adjacent bubbles is governed by van der Waal s forces of attraction. According to Prince and Blanch, predictions based on Equation 10.1 exhibited fairly good agreement with experimentally measured values of The concentration of the electrolyte varies across the film thickness. It is lower at the surface of the film and increases toward the center of the film. This dependence is given by (Marrucci 1969 Prince and Blanch 1990) 

Equation 10.2 yields Arr that is a characteristic of the electrolyte-liquid system and defines the effect of the concentration of a given electrolyte on the bubble size. Equation 10.2 can be split into two parts (1) surface tension and (2) turbulence parameters. The film thickness, 5p, is governed by turbulence parameters. Yawalkar et al. (2002a) defined a surface tension factor (STF) that represents the effect of surface tension in Equation 10.2 as (CJz) (t/c/ /Cg). Yawalkar et al. found that at C =C the values of d and STF were approximately the same irrespective of the type of electrolyte. Since the bubble diameter does not vary for C C the effect of surface tension on gas holdup should be absent for higher concentrations. Yawalkar et al. (2002a) confirmed this proposition in the case of stirred vessels. In all probabilities, bubble columns should also exhibit similar behavior. 

Similar to air-water system, in relatively high-viscosity systems, column height had a destabilizing effect on the homogenous regime (Ruzicka et al. 2001b). 

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H6. Hershman, A., The effect of liquid properties on the interaction between a turbulent air stream and a flowing liquid film. Ph.D. thesis, Univ. Illinois, Urbana, Illinois, 1960. 

They found that optimal conditions of the position of the stirrer exist in the range of 0.25 < HJd < 0.75 for both turbine and propeller stirrers. Their work suggests that beyond a Reynolds number of 20,000, the power number becomes constant. An increase in solid content increases the power consumption, while an increase in gas velocity reduces the power consumption. Kurten and Zehner (1979) examined the effect of gas velocity on the power consumption for suspension of solids and found that because of simultaneous aeration, a higher power input is required for suspension in the presence of gas. This is mainly due to the reduced liquid circulation velocity in the presence of gas bubbles. Most recently, Albal et al. (1983) evaluated the effect of liquid properties on power consumption for both two- and three-phase systems. They found that power consumption per unit volume increases with solid concentration. The influence of particle size on power consumption increases with the solids concentration. For an unconventional arrangement of a stirrer, they also found different Ne-Re curves for glycerine and CMC solutions. 

The independent variable for the correlation is impeller Reynolds number (D2Np/p.), which takes into account the effects of liquid properties on the blend time. To compute the value of the Reynolds number, a coefficient of 10.7 is necessary to put the given units in dimensionless form. 

The dispersion coefficient is essentially independent of liquid velocity. The effect of liquid properties on the dispersion coefficient has been found to be very mild and correlated by Cova (31) and Hikita and Kikukawa (32) as... 

The dispersion coefficient was found to be essentially independent of liquid surface tension. The effects of liquid properties on the dispersion coefficient were also examined by Kato and Nishiwaki (33), Akita (34), and Ulbrecht and Serna Baykara (35). 

Inamura and Tomoda [28], and Inamura et al. [2] investigated the behavior of liquid sheet generated by impingement of a liquid jet onto a solid wall. They [2] combined Dombrowski s model of sheet breakup with the sheet thickness model developed based laminar boundary-layer analysis to predict the droplet size. However, they did not provide any correlation for droplet size. Fard et al. [10] studied numerically the effect of liquid properties and nozzle geometry on the droplet size distribution produced by splash plate nozzle. Again, no correlation to relate the droplet size with the studied parameters was provided. 

Hikita, H., andKikukawa, H. (1974), Liquid-phase mixing in bubble columns Effect of liquid properties, Chemical Engineering Journal and the Biochemical Engineering Journal, 8(3) 191-197. 

Mouza, A. A., Dalakoglou, G.K., and Paras, S.V. (2005), Effect of liquid properties on the performance of bubble column reactors with fine pore spargers, Chemical Engineering... 

This section focuses on the bubble rise characteristics in liquids and liquid solid suspensions at elevated pressure and temperature. A nonwater based liquid medium is employed to illustrate the effect of liquid properties on the bubble rise velocity. For a bubble rising in a liquid olid suspension, the bubble rise velocity is discussed in light of both the apparent homogeneous (or effective) properties of the suspension and the recently evolved numerical prediction based on a computational model for gas-liquid-solid fluidization systems. Computational modeling will be covered later in Sec. 4. 

Columns Effect of Liquid Properties. Chem. Eng. Journal... 

Calculating pressure drop is of considerable importance in atmospheric absorbers, heat transfer services, and vacuum distillations. Although pressure drop plots are available for most commercial types and sizes of random dumped tower packings, these data usually have been collected on air/water systems. While the air flow rate can be corrected for changes in gas density, no adequate method exists for handling the effect of liquid properties. 

Analysis of profiles shown in Figs. A3.5—A3.12 for subcritical water [figures (a)] and critical/supercritical water [figures (b)] shows similar trends. However, for subait-ical water, there are two different values of any thermophysical property on the saturation line one for liquid and one for vapor (steam). However, for example, at pressure of 7 MPa, values of specific heat of water (5.4025 kJ/kg K) and steam (5.3566 kJ/kg K) can be very close (see Fig. A3.9(a)). Also, it can be clearly seen that pressure has almost negligible effect of liquid properties. Just closer to the saturation line, some small differences can be seen in property profiles at various pressures. 

Hikita H, Kikukawa H Liquid-phase mixing in bubble columns effect of liquid properties, Chem 9 171-174, 1974. 

For the study of flow stability in a heated capillary tube it is expedient to present the parameters P and q as a function of the Peclet number defined as Pe = (uLd) /ocl. We notice that the Peclet number in capillary flow, which results from liquid evaporation, is an unknown parameter, and is determined by solving the stationary problem (Yarin et al. 2002). Employing the Peclet number as a generalized parameter of the problem allows one to estimate the effect of physical properties of phases, micro-channel geometry, as well as wall heat flux, on the characteristics of the flow, in particular, its stability. 

The quasi-one-dimensional model allows analyzing the behavior of the vapor-liquid system, which undergoes small perturbations. In the frame of the linear approximation the effect of physical properties of both phases, the wall heat flux and the capillary sizes, on the flow instability is studied, and a scenario of the development of a possible processes at small and moderate Peclet number is considered. 

Effect of liquid composition on cement properties The properties of dental silicate cements are affected both by the concentration of phosphoric acid and by the presence of metal salts. 

Effect of physical properties Physical properties of liquid metals that have significant effects on CHF values are thermal conductivity, latent heat of vaporization, and surf ace tension. 

The liquid properties of primary importance are density, viscosity and surface tension. Unfortunately, there is no incontrovertible evidence for the effects of liquid viscosity and surface tension on droplet sizes, and in some cases the effects are conflicting. Gas density is generally considered to be the only thermophysical property of importance for the atomization of liquids in a gaseous medium. Gas density shows different influences in different atomization processes. For example, in a fan spray, or a swirl jet atomization process, an increase in the gas density can generally improve... 

SMD = 3330d "VI V P o0 052 Liquid jet from a diesel-type injector into quiescent air, effects of gas properties Hannon 436]... 

For prefilming type of atomizers, minimum droplet sizes are obtained with nozzle designs that spread liquid into thinnest sheet before subjecting its both sides to air-blast action 86] and provide maximum contact between liquid and air. 468 From experimental data obtained over a wide range of process conditions and material properties, it was found 469 that the effect of liquid viscosity on the mean droplet size is independent of that of surface tension and air velocity. Therefore, the mean droplet size can be expressed as a sum of two terms one dominated by surface tension, air velocity and air density, and the other by liquid viscosity, as suggested by Lefebvre 4691... 

Cryder, D. S. and Gilliland, E. R. Ind. Eng. Chem. 24 (1932) 1382-7. Heat transmission from metal surfaces to boiling liquids. I. Effect of physical properties of boiling liquid on liquid film coefficient. 

Cradun, 1., Reyniers, M.-F., and Marin, G.B. (2007) Effects of add properties of Y zeolites on the liquid phase alkylation of benzene with 1-octene a reaction analysis. /. Mol. Sci. A Chem., 277,... 

For batch liquid, usG f = usG. The subscript w in symbols denotes water property. SI units are used in this equation. For the derivation of this correlation, air velocities up to 0.305 m/s and liquid velocities up to 0.09 m/s were used. The Hughmark correlation has been derived for the heterogeneous flow regime. In Figure 3.31, the effect of liquid flow on gas holdup for the air-water system is presented. 

The testing procedure of properties of elastomeric vulcanizates after immersion in organic liquids is common for both natural and synthetic rubbers. ASTM D171-66 [7] used for this purpose serves as a method for estimating the comparative ability of rubbers to withstand the effects of liquids by examination of the material after removal from the liquid. However proper testing of the physical properties on swollen rubber poses many problems. 

ASTM D471-06, Standard Test Method for Rubber Property - Effect of Liquids, 2006. 

Immersion testing - Commonly used to determine the resistance of tank lining compounds to various chemicals. See ASTM D-471-Test Method for Rubber Property-Effect of Liquids. 

Giffen and Muraszew (7C) have published a very complete text on the atomization of liquid fuels, which includes an excellent bibliography. Among other topics they discuss the mechanism of jet breakup, atomizer and spray characteristics, effect of physical properties on the spray, and experimental techniques. 

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