Liquid migration

Color Plate 26 Thin-Layer Chromatograph (Section 25-1) The mixture to be separated is placed in tiny spots near the base of a plastic or glass plate coated with an adsorptive stationary phase. When the plate is placed in a shallow pool of solvent in a closed chamber, liquid migrates up the plate by capillary action. Different components of the mixture are carried along by the solvent to different extents, depending on how strongly they are adsorbed on the stationary phase. The stronger the adsorption, the slower a component travels. 

Fig. 1 Schematic illustration of slightly soluble in water dense nonaqueous phase liquid migration in the subsurface and plume formation of dissolved hydrocarbons...

We have established the Kp(t) dependence for diamond powder of 14-20 pm in size at the temperature of 2400 K and the pressure of 7.7 GPa in solid phase sintering. In this case, the Kp(t) becomes constant in 7 s [6]. However, if this powder is cobalt-infiltrated, the Kp(t) becomes constant in 0.5 s. under the same thermobaric conditions. Considering that in our experiments the liquid migration time ranges from 2 to 20 s, let us assume that Kp(t) is constant. Having integrated equation (1) we obtain... 

An internal product wash is also available in the scroll screen centrifuges. Wash liquid is added in a chamber midway along the basket, and me wash liquid migrates through the cake prior to fin3 drying and discharge. 

Wells must be specifically constructed so as to preclude any possibility of the pumped liquids migrating into strata above the repository, or backing up to the surface. Steps must also be taken to prevent others from unwittingly drilling down and into the storage depth. Materials targeted for deep well disposal include fuels, pesticides, and explosives. Radioactive materials are not included. 

However the extrudate product must have sufficient strength to withstand the processing steps subsequent to extrusion and this then argues for a low liquid content. This raises the pressure that needs to be applied by the auger. Perversely the raising of pressure also serves to raise the rate of liquid migration. Clearly a balance has to be achieved. 

The exposed surface is suppUed with liquid water coming from the inside of the board by capillary action the liquid migrates from regions with high moisture content (liquid-gas interfaces within large pores) toward regions with low moisture content (liquid-gas interfaces within small pores). 

A two-zone process develops inside the wood (1) an inner zone, where liquid migration prevails, and (2) a surface zone, where both bound-water and water-vapor diffusion take place. During this paiod, a conductive heat flux must exist inside the board to increase the temperature and to evaporate the liquid driven by gaseous diffusion. The region of liquid migration naturally reduces as the drying progresses and finally disappears. The process is finished when the temperature and the moisture content attain the outside air temperature and the EMC, respectively. 

The internal transfer (diffusion, liquid migration) becomes easier when the temperature level increases. 

The internal transfer rates depend on the local moisture content (liquid migration is usually much more effective than bound or vapor diffusion). In addition, diffusion becomes very slow when the bound-water content decreases toward zero. 

Compositional Effects on Interfacial Properties in Contaminated Systems Implications for Organic Liquid Migration and Recovery... 

The area of cross-section changes from its equilibrium value to a larger or smaller value due to liquid migration to or from the channel and serves as an indicator of the volume of the channel. The shape of the cross-section of electrowetting channels allows it to bulge or shrink by changing its side contact angle and side radius of curvature between certain limits to accommodate for influx or efflux of fluids. 

---