Liquid swell

Nonboiling Height Model This model applies the churn-turbulent assumptions to only a toppoi tiou of the fluid in the protected equipment. Below this portion, boiling does not occur and there is no liquid swell. The location of this nonboihng height is estimated from a balance of the hydrostatic effec ts and the recirculation effects. 

In the more general and more difficult case, either the punc ture is initially in the liquid space, or in a line attached to it, or the liquid swells to reach the punc ture or punc tured line, giving two-phase or all-liquid discharge. For these cases the discharge model solutions must treat four regimes, which are defined by the initial void (vapor) frac tion Ot and by the pressure ratios ... 

Time-Dependent Changes Induced by Liquid Swelling.630... 

In the 1950s, Kuhn had already observed the peculiar behavior of liquids swelling polymeric gels [5]. Indeed, a strong analogy can be proposed between solvent... 

In order to describe the effect of liquid swelling the pool void fraction, is used. The swelled height H [m] in terms of the average pool void fraction a and the height of the resting liquidiTo [m] is given by ... 

L. L. Simon, M. Introvigne, U. Fischer, K. Hungerbuhler, (2008), Batch reactor optimization under liquid swelling safety constraint, Chemical Engineering Science, 63, 770. 

Here Qt is absorbed weight of water at a time t, Qs is the weight of water at saturation, d is gel thickness, and D is the diffusion constant. Figure 2 shows diffusion constants and their temperature dependence. Many data are plotted on this graph. Fluorinert and freon immersion samples were significantly swelled by their liquids. Swelling behavior would have an effect on the diffusion coefficients due to induced stresses on the gel networks. These test values contained relatively large errors. The immersion tests at 44°C for freon and at 140°C for fluorinert were also done. 

Has the volume increase due to the heat expansion of the liquid, which accompanies the temperature increase from the initial temperature, usually room temperature, to the boiling point, as well as the liquid swell caused by the bubble formation due to boiling been sufficiently accounted for in the process design Has the condensation capacity of the succeeding condenser been calculated adequately ... 

Special problems occur in the permeation of liquids through films when the liquids swell the film. Equation (7-58) is replaced by... 

However, although the bulk volumetric gas flow rate can be directly scaled, the superficial gas velocity — that is, the velocity of the gas rising through the liquid — can be markedly different between the laboratory and plant scale leading to different degrees of foaming and liquid swell on the plant scale. 

A second potential kinetic effect may result from bulk interactions between the surface and the spreading liquid. For example, if the liquid can penetrate the surface (e.g., if the liquid can be absorbed as opposed to adsorbed), the rate of penetration may be so slow that the measured contact angle will not reflect the true equilibrium situation. Likewise, if the liquid swells the surface, the wetting line may lie on a ridge of swollen surface rather than on a flat surface, resulting in an error in 6 (Fig. 17.6). 

NR vulcanizates have very poor resistance to swelling in gasoline, mineral oils, and other nonpolar liquids, swelling as much as 1000 percent or more by volume. The resistance of NR vulcanizates to swelling by polar liquids such as water, alcohol, and others is very good. 

Formulating Considerations Highly efficient thickener needs care in dispersing in liquid. Swells rapidly in water upon neutralization with suitable base (no heat required). Effective thickeners in pH range 5-10. Thickening efficiency is reduced in presence of electrolytes. Incompatible with some cationic surfactants and some cationic polymers... 

However, for most cases involving gases and even low sorbing vapors or liquids, swelling of the polymer and non-Fickian complications are minimal. In these situations, solutions to equation 1, unconfiised by bulk flow, provide an adequate description of the process and allow estimation of the mutual diflfiision coefficient. In such cases with a constant diffusion coefficient, standard solutions of equation 1 for Mt, the amount of material sorbed (or desorbed) at time t relative to Moo, the amount of material sorbed (or desorbed) at infinite time, can be used for this estimation of the mutual diffusion coefficient. If the initial and final concentrations in the sample of thickness I are uniform and the external penetrant activity is held constant, two mathematically equivalent solutions to equation 1 are given (5) ... 

Theory and experiment show that Newtonian liquids swell at low Reynolds numbers but shrink as inertia becomes important = 1.13 for Re < 2 and B = 0.87 for Re > 100 (Middleman, 1977). Typically elastic liquids are extruded in the low Reynolds range, so the Newtonian result is subtracted from the experimental values to give an elastic swell ... 

A study of the above technique revealed that it featured efficient thermal conductivity, a uniform temperatme on the surface of the rotor and no leakage. Heat transfer was influenced by the liquid swelling factor, working temperature and rotor speed. 2 refs. 

High solubility of the liquid in the solid Swelling, transitory liquid Swelling, and/or densification... 

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