Vapor density and

Parachor is the name (199) of a temperature-independent parameter to be used in calculating physical properties. Parachor is a function of Hquid density, vapor density, and surface tension, and can be estimated from stmctural information. Critical constants for about 100 organic substances have been correlated to a set of equations involving parachors and molar refraction (200). 

Experimental values of Hqg -nd Hql for a number of distillation systems of commercial interest are also readily available. Extrapolation of the data or the correlations to conditions that differ significantly from those used for the original experiments is risky. For example, pressure has a major effect on vapor density and thus can affect the hydrodynamics significantly. Changes in flow patterns affeci both mass-transfer coefficients and interfacial area. 

Downcomer Backup Flood. For downcomer backup. Equation 4 can be used. Reference 15 states that if the downcomer backup for valve trays exceeds 40% of tray spacing for high vapor density systems I3.01bs/ft-), 50% for medium vapor densities, and 60% for vapor densities... 

Spencer, W. F., Cliath, M. M. (1970) Vapor density and apparent vapor pressure of lindane (y-BHC). J. Agric. Food Chem. 18,529-530. 

Vapor-Liquid Gravity Separator Design Fundamentals The critical factors in the performance of a horizontal separator are the vapor residence time and the settling rate of the liquid droplets. However, two other factors enter into the design—the vapor velocity must be limited to avoid liquid entrainment, and there must be sufficient freeboard within the vessel to allow for a feed distributor. For vertical separators, the design is based on a vapor velocity that must be less than the settling velocity of the smallest droplet that is to be collected, with due allowance for turbulence and maldistribution of the feed. The vapor residence time is a function of the vapor flow rate (mass), vapor density, and volume of vapor space in the separator, based on the following ... 

If released under atmospheric conditions the gas will either rise or fall depending on its vapor density and will be directed in the path of the prevailing wind. In the absence of a wind, heavier gases will collect in low points in the terrain. Normally atmospheric gas releases are dispersed within relatively close distances to their point source, usually about 3 meters (10 ft.) (Reference NFPA 30, Table 5-3.5.3). These atmospheric releases, if ignited, will bum relatively close to the source point, normally in a vertical position with flames of short length. 

Jean Baptiste-Andr Dumas, 1800-1884. Professor of chemistry at the Athenaeum and at the Sorbonne. He devised a method of determining vapor density, and developed the theory of types m organic chemistry, which he defended against Berzelius duahstic electrochemical theory. From a study of the aliphatic alcohols, Dumas and Pehgot developed the conception of homologous series, See also ref. (62). 

It is true, then, that vapor density and feet of head are not related. But if the product of the two numbers do not result in sufficient AP to push the gas from the drum into the absorber, then the gas flow will stop. It will stop and then reverse its direction of flow. And that is what causes surge. 

Figure 13.42. Efficiency of Glitsch V-l valve trays on isobut-ane/butane and cyclohexane/n-heptane as a function of vapor density and percent of flood, measured by Fractionation Research Inc. (Glitsch Inc., Bulletin 160, Dallas, TX, 1958).

The pressure is 60Torr, at which the saturation temperature of steam is 106°F. The superheat of 24°F is neglected in figuring the vapor density and velocity. 

Mass chromatography has several advantages (2) over conventional methods of molecular weight measurement such as cryoscopy, ebulli-ometry, vapor density, and osmometry. For example, these methods require a pure sample and are dependent on ideal solution behavior or extrapolation to infinite dilution. 

Duarte-Garza, H.A., Hwang, C.-A., Kellerman, S., Miller, R.C., Hall, K.R., Holste, J.C. (1997a) Vapor pressure, vapor density, and liquid density for Ll-dichloro-l-fluoroethane (R-141b). J. Chem. Eng. Data 42, 497-501. 

Increases vapor density and therefore vapor-handling capacity. This leads to major reductions in column diameter and capital costs under vacuum, and to smaller reductions up to pressures of 50 to 150 psia (6). 

A very considerable portion of the text has been wholly rewritten, and the entire text has been subjected to a revision and rearrangement. Specific new exercises and discussions which have been introduced include such topics as the determinations of vapor density and molecular weight, the standardization of acids and the titration of acids and bases, Faraday s law, and the use of the pH scale of hydrogen-ion concentration. Several new preparar tions have been introduced, and a few of the old ones have been discontinued. A complete list of apparatus and chemicals required in the course has been added to the Appendix. 

The workimg medium in refrigeration systems is called the refrigerant. Fluids used for this purpose should ideally be nontoxic and chemically inert, with low boiling points93,94. They should have high enthalpies of vaporization per unit mass, high vapor densities and low miscibilities with water, since the latter can lead to freezeup in the expansion devices or corrosion. 

The vapor density and latent heat are evaluated at the saturation temperature, T, which is 100°C and are ... 

Whereas light and heavy water have nearly identical relative permittivities and dipole moments, it can be concluded from the greater boiling point, heat of vaporization, density, and viscosity of heavy water, that liquid D2O is more structured than the already highly structured H2O at room temperature cf. Fig. 2-1 in Section 2.1). This is also consistent with the fact that salts acting as structure-breakers are generally less soluble in D2O than H2O [446]. 

Profiles of vapor density and temperature have been computed for two juxtaposed water drops by Carstens et al. (4) with comments by Williams and Carstens (5). The formalism is herein generalized, in accordance with Williams (6), to include drops with distinct thermal conductivities and latent heats this allows consideration of the solid phase as well as the possibility that one sphere is nonvolatile. 

PVT, Vapor Density, and Virial Coefficient. In these three techniques the pressure (of a known volume and weight of gas) is measured over a temperature range. The data may be treated in two ways by assuming that the real gas is a mixture of perfect gases (each gas being one of the species), or by describing the behavior of the real gas by a virial equation. 

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