Liquified Gas

ESTIMATING EVAPORATION LOSSES FROM LIQUIFIED GASES... 

Liquified gases are sometimes stored in well-insulated spherical containers that are vented to the atmosphere. Examples in the industry are the storage of liquid oxygen and liquid ammonia in spheres. If the radii of the inner and outer walls are r, and r, and the temperatures at these sections are T, and T, an expression for the steady-state heat loss from the walls of the container may be obtained. A key assumption is that the thermal conductivity of the insulation varies linearly with the temperature according to the relation ... 

They are widely employed in the manufacture, storage and distribution of liquified gases, particularly on sea and road tankers. The most popular alloy for cryogenic applications is 4.5% magnesium alloy (N8). Table 3.33 gives the boiling points of the most common cryogenic liquids and the minimum temperatures at which various materials can be used. 

The Joule-Thomson expansion can be used to liquify gases. An expansion at pressure and temperature conditions inside the dashed line envelope where /o r < 0 cools the gas. This gas is used to precool the incoming gas so that the expansion occurs at still lower temperatures. Continuing this process eventually cools the gas until it liquifies. 

Liquified gases may be stored fully refrigerated, with the liquid at its bubble point at near atmospheric pressure fully pressurized, i.e. at ambient temperature or semirefri-... 

First, there must be a release of a flammable material at suitable conditions of pressure or temperature. These include liquified gases under pressure, ordinary flammable liquids (especially at elevated pressures and/or temperatures), and flammable gasses. When a flammable liquid spills, some or all of it will vaporize and/or form an aerosol. This dispersion is called a vapor cloud. 

Cryogenic Pertaining to liquified gases stored at temperatures approaching absolute zero. Normally, they have a boiling point of about -100°C. 

Shatenshtein, A. I. (1939a). Liquified Gases as Solvents ( Szhizhennye gazy kak rastvoriteli ), Leningrad. 

We need not limit the choice of chemical candidates only to those that can be used in a water-treating solution. Application with hydrocarbon solvents or liquified gases with subsequent recovery of the carrier may prove practicable. 

A number of compressed and liquified gases are used as refrigerants and aerosol propellants. These include nitrous oxide, nitrogen, carbon dioxide, propane, and butane. The use of chlorofluorocarbons (CFCs) is restricted because of environmental pollution leading to health hazards. These have been replaced by hydrogenated fluorocarbons (HFCs), which are less likely to cause environmental pollution. 

Wheatley, C. J. 1986. Factors Affecting Cloud Formation from Releases of Liquified Gases. IChemE Symposium on Refinement of Estimates of the Consequences of Heavy Toxic Vapor Releases, Manchester, UK. London IChemE. 

Structural models for molten salts have been proposed by several authors Bockris [1-3], Stillinger [4], Zarzycki [5], Janz [6], Kleppa [7], Blander [8], and others. These structural models are based on the older theories of the liquid state, which were applied for molecular liquids, liquified gases, molten metals, etc. Some of these models will be treated in the following. 

Scientists realized early on that the forces between symmetrical, nonpolar molecules existed but were weak. Because they are weak, very low temperatures are required to liquify gases in which the molecules have pure covalent bonds. Flydrogen (H2), for instance, must be cooled to -252°C, only 21° above absolute zero, before it condenses into a liquid. The question was, Why does it condense at all What forces are acting on the nonpolar molecules... 

Protective radiation shields are used to reduce the radiative exchange between walls at different temperatures thin foils or sheets made of good reflecting materials are placed between the walls, Fig. 5.66. The spaces between the protective shields are normally evacuated so that heat transfer by convection is prevented. This multi-layer arrangement is used predominantly in cryogenic applications for the insulation of containers for very cold liquified gases. 

Friedrichs, F. On Extraction with Liquified Gases and the Ammonoly-sis of Hydrazine Sulfate Journal of the American Chemical Society (1913) 35 244-247... 

Ti-5 aluminum-2.5 tin (grade 6) is used for high temperature strength in process equipment and also as hardware to handle cryogenic liquified gases. 

None would apply to releases of flammable liquids or liquified gases]... 

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