Condensational wetting

To l.Oequiv of the chiral auxiliary substituted jV. JV -dimethylmethanimidamide (1) in 1 mL/mmol of toluene are added 1.5 equiv of 1,2,3.4-tetrahydroisoquinoline and the mixture is refluxed until the conversion is complete [vpc or absence of dimethylamine evolution from the top of the condenser (wet litmus paper)]. The addition of a few crystals of ammonium sulfate as an acid catalyst is recommended. 

The water content of furfural is critical and must be kept to a minimum. In order to dehydrate the solvent a pair of distillation columns is utilized. Condensed wet solvent separates into two layers in a settling drum. The top layer, which is lean in furfural, is separated into saturated solvent vapor and solvent-free water in the furfural-from-water stripper. The solvent-rich layer is separated in the water-from-furfural stripper into wet solvent vapor and dry furfural. 

A further small quantity of impure glycine can be isolated by concentrating the filtrates obtained on recrystallization. The liquors from the first precipitation, containing ammonium bromide, pyridine hydrobromide, excess pyridine, and alcohol-soluble by-products, may be treated as follows The mixture is first acidified with mineral acid and the methyl alcohol recovered by distillation with a column. The residue is rendered strongly alkaline and the bulk of the ammonia removed by boiling under a reflux condenser wet pyridine can be recovered by downward distillation and treatment of the distillate with solid sodium hydroxide. 

Of the four types of wetting phenomena examined in the previous section, only immersional wetting lends itself to direct microcalorimetric measurement spreading and adhesion experiments would involve too small interfacial areas (say, no more than c. 100 cm2), whereas condensational wetting would require measurements up to p/p° = 1. As we saw in Chapter 3, these are the conditions where accurate measurements of the amounts of gas adsorbed are difficult to achieve. For this reason we confine the following recommendations to immersion microcalorimetry.. ... 

Two distinct forms of condensation are observed Jilni condensation and dropwise condensation. In film condensation, the condensate wets the surface and forms a liquid film on the surface that slides down under the influence of gravity. The tliickne.ss of the liquid film increases in the flow direction as more vapor condenses on the film. This is how condensation normally occurs in practice. In dropwise condensation, the condensed vapor forms droplets on the surface instead of a continuous film, and the surface is covered by countless droplets of varying diameters (Fig. 10-20). 

Merpol . (DuPont] EO condensate wetting agent, detergent, penetrant, emulsifier, leveling t ent, dye assistant, an-Ustat, emulsifia, stabilizer fw textile, paper, paints, inks, medichial ointments, antiperspirants, cosmetics. 

During condensation, the liquid collects in one of two ways, depending on whether it wets the cold surface or not. If the liquid condensate wets the surface, a continuous film will collect, and this is referred to as filmwise condensation. If the liquid does not wet the surface, it will form into numerous discrete droplets, referred to as dropwise condensation. All surface condensers today are designed to operate in the filmwise mode, since long-term dropwise conditions have not been successfully sustained. 

Corrosive—High Flow Velocity and Turbulence Feedwater, condensate, wet steam... 

Or if the part surfaces are cooler than the boiling point of the vapor, the vapor will condense — wetting/rinsing the surface with distilled (pristine) solvent. 

Cyclones Fabric filters Wet scrubbers Electrostatic precipitators Incineration Adsorption Absorption Condensation Wet scrubbing with chemical reaction Biofiltration Vapor neutralization Air dilution... 

K. Siderakis, D. Agoris, J. Stefanakis, E. Thalassinakis, Influence of the profile on the performance of porcelain insulators installed in coastal high voltage networks in the case of condensation wetting, lEE Proceedings, Science, Measurement and Technology, Vol. 153, Issue 4, p. 158-163. 

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