Particulate Suspensions

Nasal Sprays Clarity, microbial bioburden, pH, particulate matter, unit spray medication content uniformity, droplet and/or particle size distribution, weight loss, pump delivery, microscopic evaluation of suspensions, particulate matter, extractables, leachables from plastic and elastomeric components of container closure and pump. 

These can be grouped into suspensions, particulates, liposomes and emulsions. 

A third consequence of presence of suspension particulates can also be realized, by... 

A third consequence of presence of suspension particulates can also be realized, by referring to the blood flow morphology, as an example. After the RBCs drift toward the channel centerline (due to reasons as explained earlier), the cells eventually equilibrate at some characteris-... 

D J Bell, K H Brunner. A method for the evaluation of floe break-up in centrifuges. Filtration+Separation, july/August 1983 R C Klimpel, C Dirican, R Hogg. Measurement of agglomerate density in flocculated fine particle suspensions. Particulate Sci Technol 4 (1986) 45-59 R C Klimpel, R Hogg. Evaluation of floe structures. Colloids and Surfaces 55 (1991) 279-88... 

In process plants, source materials (reactants) are converted into merchantable products. Source materials and products may be gaseous, liquid or solid substances or even mixtures of these different states (suspensions, particulates etc.) Products may be intermediate or end products which are being processed step by step. The result is a whole host of possible problems or types of plants that solve these problems. The following list shows at least some typical products of process plants and their lines of business ... 

An aerosol is a suspension of either a solid or a liquid in a gas. Fog, for example, is a suspension of small liquid water droplets in air, and smoke is a suspension of small solid particulates in combustion gases. In both cases the liquid or solid particulates must be small enough to remain suspended in the gas for an extended time. Solid aerosol particulates, which are the focus of this problem, usually have micrometer or submicrometer diameters. Over time, solid particulates settle out from the gas, falling to the Earth s surface as dry deposition. 

In the case of particulate fouling, one of the more common types, insuring a sufficient flow velocity and minimizing areas of lower velocities and stagnant flows to help keep particles in suspension is the most common means of deahng with the problem. For water, the recommended tubeside minimum velocity is about 0.9 to 1.0 m/s. This may not always be possible for moderate to high-viscosity fluids where the resulting pressure drop can be prohibitive. 

The resistances, when incorporated into equations descriptive of cross-flow filtration, yield the general expression for the permeate flux for particulate suspensions in cross-flow-electrofiltration systems. 

Coal drying rotary, screen, suspension. Dust, smoke, particulates, sulfur oxides. Exhaust systems with cyclones and... 

The real atmosphere is more than a dry mixture of permanent gases. It has other constituents—vapor of both water and organic liquids, and particulate matter held in suspension. Above their temperature of condensation, vapor molecules act just like permanent gas molecules in the air. The predominant vapor in the air is water vapor. Below its condensation temperature, if the air is saturated, water changes from vapor to liquid. We are all familiar with this phenomenon because it appears as fog or mist in the air and as condensed liquid water on windows and other cold surfaces exposed to air. The quantity of water vapor in the air varies greatly from almost complete dryness to supersaturation, i.e., between 0% and 4% by weight. If Table 2-1 is compiled on a wet air basis at a time when the water vapor concentration is 31,200 parts by volume per million parts by volume of wet air (Table 2-2), the concentration of condensable organic vapors is seen to be so low compared to that of water vapor that for all practical purposes the difference between wet air and dry air is its water vapor content. 

G Pollutant occurs as a gas L Pollutant occurs as a liquid S Pollutant occurs as a solid P Pollutant occurs in particulate form A Pollutant occurs in aqueous solution or suspension... 

In other parts of the world, plywood adhesive fillers are obtained from local sources and may be quite different than those used in North America. In Southeast Asia, banana flour is quite important. In Europe, calcium carbonate (chalk) is often used. Nearly any fibrous material or fine particulate material capable of forming a functionally stable suspension can be made to work if the formulator is sufficiently skillful. However, the mix formulator will be very specific about the type and grade of filler to be used in a particular mix. Substitutions may lead to serious gluing problems. 

Aerosol A special class of particulate consisting of colloidal suspensions larger than molecular size, but not large enough to settle under gravity. 

Sedimentation I he process of settling solid particulates out of suspension in a fluid or a gas. 

Suspended matter (particulates) Particles that remain in suspension in a gas or a fluid for a sufficient time in to be detected by physical means. 

Transport velocity The air velocity required in an extract duct conveying dust to ensure that the particulate matter remains in suspension and does not settle. 

As mentioned above batch crystallizers are usually simple vessels provided with some means of mechanical agitation or particulate fluidization. These have the effect of reducing temperature and concentration gradients, and maintain crystals in suspension. Baffles may be added to improve mixing and heat exchange or vacuum systems may be added, as appropriate. Various design combinations are available and some are illustrated in Figure 7.1. 

Seawater systems should be designed to avoid excessive water velocities, turbulence, aeration, particulates in suspension, rapid changes in piping section and direction. Likewise, extended periods of shutdown should also be avoided since stagnation of contained seawater, will result in bacterial activity and HjS production with consequential and perhaps serious corrosion and health and safety problems. 

Particulates can be removed from aqueous suspension by attachment to rising air bubbles. This method is known as flotation, which is widely used for recovery of small particles... 

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