Liquid superheating

Mist flow, one component In a one-component system with finely dispersed drops in the mist flow, the mass transfer between phases over a large interfacial area has to be considered. For the compression wave the frozen state can be assumed to be subcooled liquid, superheated vapor conditions generated by the wave are fairly stable, and the expressions for the two-component system are valid (Henry, 1971) ... 

Unlike supercooling of liquids, superheating of crystalline solids is difficult due to nucleation of the liquid at surfaces. However, by suppressing surface melting, superheating to temperatures well above the equilibrium melting temperature has... 

In Fig. 12, we show the computed values of bubble radius for superheated liquid propane at two pressure levels 1 and 5 atm. Consider the inertial rate first. At 1 atm, liquid superheated propane attains the limit of superheat at about 328 K, where the vapor pressure is —18.9 atm. With Eq. (12), Tinertiai 52f m, where t is in seconds. At 5 atm, the driving force [Eyp(To) - Eq] is less than that at 1 atm, but the difference is slight. Thus, the 1 and 5 atm radii are shown as a single line in Fig. 12. 

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

Boiling Mechanisms Vaporization of liquids may result from various mechanisms of heat transfer, singly or combinations thereof. For example, vaporization may occur as a result of heat absorbed, by radiation and convection, at the surface of a pool of liquid or as a result of heat absorbed by natural convection from a hot wall beneath the disengaging surface, in which case the vaporization takes place when the superheated liquid reaches the pool surface. Vaporization also occurs from falling films (the reverse of condensation) or from the flashing of liquids superheated by forced convection under pressure. 

Casal, J., and Salla, J. (2006) Using liquid superheating for a quick estimation of overpressure in BLEVEs and similar explosions, Journal of Hazardous Materials A137, 1321-1327. 

To start with, let us consider a particular case of metastable states - a liquid superheated with respect to the liquid-vapor equilibrium temperature. For simplicity let us take a pure liquid at positive pressures, see Fig. 1. The region of superheated states is limited from below by the binodal Ts(p) and from above by the experimental line of attainable superheat, or, in other words, the line of spontaneous boiling-up T (p Cxp) of the liquid. An understandable limitation is imposed on the volume of superheated sample V and the time period Cxp of experiment. Naturally, the experimental time should be shorter than the life time t of the metastable state. 

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