Liquid metals boiling temperatures

The availability of large quantities of liquid helium as well as an excellent support staff led to the undertaking of many experiments at 8 K (the boiling temperature of helium) as well as the lower temperatures obtained by pumping. One subset was the measurement of the resistivity (conductivity) of metals, since this property was useful as a secondaiy thermometer. Although a linear decline was obseived, various speculations were made as to what the result would be when zero absolute temperature was reached. In April 1911 came the surprising discoveiy that the resistivity in mercury disappeared. At first the sur-... 

An organic liquid is boiling at 340 K on the inside of a metal surface of thermal conductivity 42 W/m K and thickness 3 mm. The outside of the surface is heated by condensing steam. Assuming that the heat transfer coefficient from steam to the outer metal surface is constant at 11 kW/m2 K, irrespective of the steam temperature, find the value of the steam temperature to give a maximum rate of evaporation. 

The volatile metal is separated by distillation and condensed. Mercury is the only metallic element that is liquid at room temperature (gallium and cesium are liquids on warm days). It has a long liquid range, from its melting point of — 39°C to its boiling point of 357°C, and so it is well suited for its use in thermometers, silent electrical switches, and high-vacuum pumps. 

Binary liquid metal systems were used in liquid-metal magnetohydrodynamic generators and liquid-metal fuel cell systems for which boiling heat transfer characteristics were required. Mori et al. (1970) studied a binary liquid metal of mercury and the eutectic alloy of bismuth and lead flowing through a vertical, alloy steel tube of 2.54-cm (1-in) O.D., which was heated by radiation in an electric furnace. In their experiments, both axial and radial temperature distributions were measured, and the liquid temperature continued to increase when boiling occurred. A radial temperature gradient also existed even away from the thin layer next to the... 

Chen, J. C., 1965, Non-equilibrium Inverse Temperature Profile in Boiling Liquid Metal Two-Phase Flow, AIChE J. 77(6) 1145-1148. (4)... 

Hoffman, H. W., 1964, Recent Experimental Results in ORNL Studies with Boiling Potassium, Third Annual Conf. on High Temperature Liquid Metal Heat Transfer Technology, Oak Ridge Natl. Lab., Oak Ridge, TN, ORNL-3605, vol. 1, pp. 334 350. (4)... 

Holtz, R. E., 1966, The Effect of Pressure-Temperature History upon Incipient Boiling Superheats in Liquid Metals, ANL-7184, Argonne Natl. Lab., Argonne, IL. (2)... 

Tippets, F. E., J. A. Bond, and J. R. Peterson, 1965, Heat Transfer and Pressure Drop Measurements for High Temperature Boiling Potassium in Forced Convection, Proc. Conf. on Applied Heat Transfer Instrumentation to Liquid Metal Experiments, ANL-7100, p. 53-95, Argonne National Lab., Argonne, IL. (3)... 

Mercury (chemical symbol Hg, from the Latin name of the metal, hydrar-gyrium, liquid silver), previously also known as quicksilver is, at ordinary temperatures, a silvery white liquid metal that boils at 360°C. The metal is occasionally found in nature in the native state. Most mercury has been derived, however, from the red mineral cinnabar (composed of mercuric sulfide) that was also used in the past as a red pigment known as vermilion (see Textbox 41). The Greek philosopher Aristotle, writing in the fourth... 

Figure 2.17. Liquid-liquid and solid-gas equilibria in intermetallic systems. In a map based on the so-called Mendeleev number coordinates the different binary combinations are represented. Only those combinations have been coded for which the existence of liquid miscibility gaps (or of solid-gas equilibria) is known. (In the same systems, other equilibria, the formation of compounds, etc. may be present). For many systems data are lacking probably in the bottom-left comer of the figure many more boxes could be added to those representing miscibility gap. Notice that the solid-gas equilibria are relevant to systems formed by metals with a large difference between their boiling temperatures.

Some comments are needed on these data in order to explain the differences in surface tension data and molecular structure. The range of y is found to vary from ca. 20 to over 1000 Nm/m. The surface tension of Hg is high because it is a liquid metal with a very high boiling point. This indicates that it needs much energy to break the bonds between Hg atoms to evaporate. Similarly, y of NaCl as a liquid (at high temperature) is also very high. The same case is found for metals in liquid state. 

The high boiling points mean that liquid metals are usable at atmospheric pressure at high temperatures. Other liquids require pressure application if they are to be used at high temperatures. Data (L3) for four liquid metals are shown in Figs. 26 and 27. The data of Farmer (F2) for mercury at vacuum are described as preliminary and may be subject to revision. 

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