Vaporizers cryogenic

Cl2 chlorine explosive NCI3 formed with excess chlorine or heat oxidizer toxic vapor cryogenic liquid spill ... 

Third harmonic, four wave sum-frequency mixing, four-wave difference-frequency mixing Infrared (3.3 fim) to XUV (57 nm) CO2, CO, Nd, ruby, dye, excimer Rare gases, molecular gases, metal vapors, cryogenic liquids... 

Measurement Technique. The thermal expansion measurements were performed in a fused silica dilatometer with associated LVDT sensing equipment. The dilatometer has a resolution of 13 nm (0.5 X 10 in). Temperature is controlled at 10° intervals by utilizing a throttling dewar, which uses the sensible heat resulting from vaporized cryogen and proportional controllers, which permit temperature control of 0.1 K in the entire temperature range. 

The separation of nitrogen from natural gas reHes on the differences between the boiling points of nitrogen (77.4 K) and methane (91.7 K) and involves the cryogenic distillation of a feed stream that has been preconditioned to very low levels of carbon dioxide, water vapor, and other constituents that would form soHds at the low processing temperatures. 

Because of Hquid helium s uniquely low temperature and small heat of vaporization, containers for its storage and transportation must be exceedingly weU insulated. Some containers are insulated with only a fairly thick layer of very efficient insulation, but containers with the least heat leak use an inexpensive sacrificial cryogenic Hquid, usually Hquid nitrogen, to shield thermally the Hquid helium contents. 

An extremely important safety consideration for both heated and cryogenic tanks is that lower boiling Hquids must not be introduced into the tank. These Hquids can boil and cause a frothover or a violent evolution of vapor, followed by tank failure. 

Tanks with contents at lower than atmospheric temperature may require insulation to minimize heat absorption. The insulation must have a vapor barrier at the outside to prevent condensation of atmospheric moisture from reducing its effectiveness. An insulation not damaged by moisture is preferable. The insulation techniques presently used for refrigerated systems can be apphed (see subsection Fow-Temperature and Cryogenic Storage ). 

Applications The common Heliflow apphcations are tank-vent condensers, sample coolers, pump-seal coolers, and steam-jet vacuum condensers. Instant water heaters, glycoLwater seivdces, and cryogenic vaporizers use the spiral tube s ability to reduce thermally induced stresses caused in these apphcations. 

Fig. 3. A model integrated adsorption/electrothermal regeneration/cryogenic vapor recovery system for volatile organic compounds [91]. Reprinted from Gas Sep. Purif, Volume 10, Lordgooei, M., Carmichael, K. R., Kelly, T. W., Rood, M. J. and Larson, S. M., Activated carbon cloth adsorption cryogenic system to recover toxic volatile organic compounds, pp. 123-130, Copyright 1996, with permission from Elsevier Science.

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