Subcooled, term

Fhix-force-condensation scrubbers combine the effects of flux force (diffiisiophoresis and thermophoresis) and water-vapor condensation. These scrubbers contact hot, humid gas with subcooled liquid, and/or they inject steam into saturated gas, and they have demonstrated that a number of these novel devices can remove fine particulates (see Fig. 25-24). Although limited in terms of commercialization, these systems may find application in many industries. 

HEM for Two-Phase Orifice Discharge For orifice or nozzle flow, the friction term and the potential energy term in Eq. (26-82) are negligible, so it can be integrated in general across both subcooled and flashing regions thusly ... 

In Fig. 2.36 the dimensionless heat flux q is plotted versus the difference (Ti ax — Ts). The dimensionless heat flux is defined as q = [ /(GCpA7 )](7iiax/7iiean), where q is the heat flux, G is the mass flux, Cp is the specific heat, AT Ts — Tja, Ts is the saturation temperature, Tin is the water temperature supplied to the inlet collector, and Tmax and Tmean are maximum and average temperature of the heated surface, respectively. The term qj(GcpAT) reflects the effect of subcooling. 

Elkassabgi and Lienhard (1988) provided an extensive subcooled pool boiling CHF data set of 631 observations on cylindical electric resistance heaters ranging from 0.80 to 1.54 mm (0.03 to 0.06 in.) in diameter with four liquids (isopropanol, acetone, methanol, and Freon-113) at atmospheric pressure and up to 140°C (252°F) subcooling. They normalized <7 ritsub data by Sun and Lienhard s (1970) saturated q"Tix SL prediction in terms of B,... 

Effect of subcooling As shown in Eq. (2-142), the effect of subcooling is expressed by the term c/"ub. For ordinary liquids, Ivey and Morris (1962) recommended a modified Kutateladze equation ... 

Explain in words the terms subcooled liquid, superheated liquid, and supercritical fluid. 

Regression Equations Relating Solubility S (mol/L) to Kow. The Solubility is of the Liquid or Subcooled Liquid State. For Solids, a Fugacity Ratio Term Must be Included... 

Of these, the feed mixture may or may not vary, but is generally taken as given. The column pressure and the degree of subcooling are normally fairly constant. The main operational variables are the reflux ratio R and the heat input to the reboiler QR and once these are set, the amount of product withdrawal at the bottom or at the top will also be given by the product specifications. An optimum exists for the reflux ratio in terms of operating costs, and normally a number of ratios are tested, and the economics of each scenario is investigated, before a decision is reached. 

Now the heat transfer rate depends on hxj. If it is assumed, therefore, that subcooling effects are negligible if the term (1 + 0.687a)1/4 is 1.01 or less, it will be seen that subcooling effects are negligible if Ja is approximately less than 0.06, i.e., if ... 

A similar expression is found for nucleation rate from melt systems, except the driving force is written in terms of the subcooling, as seen in Equation (4.5). 

Define vapor pressure, triple point, equilibrium, dew point, bubble point, saturated, superheated, subcooled, and quality, and be able to locate the region or point in a p-T chart in which each term applies. 

If a body of vapor can be sufficiently subcooled without contact with a surface (by radiation, for example), theory predicts that a liquid phase can form spontaneously. This process is termed homogenous condensation, and fog formation is often cited as an example. However, the subcooling required is so great that it is unhkely to occur in any process situation. Fog formation does occur in process condensers, but the probable mechanism is condensation on tiny droplets carried over from a previous processing step (a distillation column, for example, where bubble collapse produces large numbers of submicroscopic droplets). 

The subcooM region is modelled separately along with the downcomer pipework. As far as the drum model is concerned, its sole contribution comes in determining liquid level, where it adds a constant term to the liquid volume. As mentioned previously, the subcooled region may make up typically about 10% or less of the water volume of the drum, and so its effect on steam drum dynamics is second-order only. 

The thermal condition of die feed stream introduces the need for nn energy balance at die feed stage. The feed may be a subcooled liquid, a saturated liquid, a mixture of liquid and vapor, a saturated vapor, or a superheated vapor. A special term may be defined diet can acoonnt for the thermal condition of the... 

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