Cold-condensation effect

The two water concentrations (temperate and Arctic) are similar, even though the air concentration in the Arctic is an order of magnitude less than temperate air. This temperature driven phenomenon that favours chemical partitioning to surfaces is commonly known as the cold condensation effect and has resulted in the worrying rise in persistent organic pollutants in the polar environments. 

This effect is not observed for the rest of organochlorine chemicals that are lower soluble. The explanation of this fact is given by the so called cold condensation effect that is typical for more volatile organic chemicals. 

The Global Distillation Model, also called the Grasshopper Effect and the Cold-Condensation Effect, predicts a global fractionation of these chemicals will occur whereby more... 

Where Water Hammer Occurs. Water hammer can occur in any water supply line, hot or cold. Its effects can be even more pronounced in heterogeneous or biphase systems. Biphase systems carry water in two states, as a liquid and as a gas. Such a condition exists in a steam system where condensate coexists with live or flash steam in heat exchangers, tracer lines, steam mains, condensate return lines and, in some cases, pump discharge lines. 

Condenser - either silica cold finger condensers, effective length 140 mm, or soda glass air condensers, approximately 750 mm. 

Figure 10 - Zinc Elimination Curves - One Showing Effect of Correction Temperature 560 C L = 30 cm, Various Vacua, Cold Condenser, CC, or Liquid Zinc Condenser, LZ, at Zinc Melting Point, 420° C, See Text and Reference 2...

Removal of only the least volatile species from a gas stream is feasible when a temperature ccin be found at which its vapor pressure is sufficiently less than its partial pressure in the gas stream that condensation is essentially complete, while the vapor pressures of other constituents are higher than their partial pressures over the trap. Assuming equilibrium conditions and insolubility of the other species in the condensed phase, passage of the g B stream through the cold trap effects the desired separation quite simply. 

Answer by Author Although I have not had any experience with Freon-blown foams, 1 would suggest that the condensation effects would be similar to that found with other closed-cell materials. In order to minimize or eliminate these effects, it is necessary to provide a perfect gas seal around the insulation and thereby preclude the possibility of air contacting the cold tank surfaces during the cool-down time. 

Sublimation.—This is a valuable means for the purification of many organic substances and is admirably adapted for small scale work since losses are generally small. Sublimation may be carried out either at atmospheric pressure or under reduced pressure. The apparatus shown in Fig. XII, 2, 20 is simple and effective the sublimate is collected on the cold finger condenser. 

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