Fines surface capture

Body-aid (i.e., the filter-aid) and precoating are often mentioned in connection with pressure filtration and the difference in their application is (1) Body aid is used when the slurry is low in solids content with fine and slimy particles that are difficult to filter. To enhance filtration coarse solids with large surface area are added to the slurry and serve as a body-aid that captures and traps in its interstices... 

When liquid droplets are present in a gas stream, glass microfiber filter tubes can efficiently separate suspended liquids from gases. The filter tubes capture the fine droplets suspended in the gas and cause them to run together to form large drops within the depths of the filter tube. The large droplets are then forced by the gas flow to the downstream surface of the filter tube, from where the liquid drains by gravity. This process is called coalescing. 

A further objection to the use of a scoop it is liable to be size-selective favoring the collection of fine particles. The reason for this is that, when the scoop is removed from the material, some particles will flow down the sloping surface of the powder retained in the scoop the finer particles tend to be captured in the surface craters and retained, whereas coarse particles are more likely to travel to the bottom of the slope and be lost. The effect is particularly important if a flat blade (such as a spatula) is used for the removal of the sample. 

Deep-bed filters are employed for slurries with very dilute concentration less than 1000 ppm (parts per million by weight). The deep-bed has pores in which the fine particles are caught. Capture of particles in deep-beds depends upon transport mechanisms that carry the particles to the surface of the medium. As the deposit builds up, the permeability ultimately drops to a point where the bed must be regenerated or discarded. The deep beds are in the form of granular media (sand, crushed anthracite coal, garnet, usually backwashable)... 

More often, three-dimensional gridded meteorological forecast data provided by mesoscale meteorological models such as MM5 will be available. The resolution of the grid will typically be on the order of 1 km, which is too large to capture microscale surface features. Mesoscale model results can be coupled with fine-scale models by enforcing conservation of mass to provide enhanced fine-scale detail. 

An electric field can be applied to an insulator with no electrode present through electrostatic charging (sometimes called xerographic charging) [42]. The process involves the generation of ions in the vicinity of a metal point or fine wire by the field emission of electrons from (or to) the metal and the subsequent (or prior) capture (or release) of the electrons by gas atoms. The ions are then drifted to the specimen surface in an applied field and, under certain circumstances, the ions remain stable on the surface to generate an electric field between that surface and the back surface that has been held at ground potential. For this process to take place the interaction between the ions and solid surface must create an electronic level (the so-called chemisorption level of the ion on the insulator surface) that lies well within the band gap of the... 

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