Separation equipment flotation

Following the biological waste water purification, an easy separation of activated sludge flocks can be achieved by flotation. To facilitate this separation, the flotation cell is subdivided into two parts, each having equal superficial areas, Fig. 58. The inner cylindrical vessel serves as the aeration chamber, this being equipped with the forementioned funnel-shaped nozzle. Here, particles are brought into intimate con-... 

A variety of industrial equipment has been used to carry out the flocculation process and the separation of the flocculated materials producing a well-defined sludge suspension layer, which can be removed. Some plant operates with sludge feedback to enable more efficient adsorption. Sludge flocks can also be separated by flotation. 

To provide adequate space for the fusion reactor, electric generators, the electrolysis plant and the support equipment, the floating structure will be hundreds of meters in length and width. It will be supported by several hundred flotation-structures. Because of their large number the loss or leakage of one flotation structure, or even several, will not disable the platform. There will be time available for repair or replacement of the floats on a normal maintenance schedule. The volume inside the flotation structures will be available for support equipment such as water pumps, electrolysis units, deuterium separation equipment or simple storage. 

These can be clarified relatively easily in separation equipment such as corrugated plate separators, flotation units, hydrocyclones or centrifuges. An example, the Compact Clarifier, is shown in Figure 6.18. The efficiency of the equipment is usually enhanced by the application of flocculants/coagulants which draw the finely dispersed oil droplets and suspended solids together into larger particles which are separated more effectively, in a manner that is akin to suspended-solids flocculation. The oil droplets have a substantially... 

The raw ROM (run of mine) ore is reduced in size from boulders of up to 100 cm in diameter to about 0.5 cm using jaw cmshers as weU as cone, gyratory, or roU-type equipment. The cmshed product is further pulverized using rod mills and ball mills, bringing particle sizes to finer than about 65 mesh (230 p.m). These size reduction (qv) procedures are collectively known as comminution processes. Their primary objective is to generate mineral grains that are discrete and Hberated from one another (11). Liberation is essential for the exploitation of individual mineral properties in the separation process. At the same time, particles at such fine sizes can be more readily buoyed to the top of the flotation ceU by air bubbles that adhere to them. 

In 1981, a novel flotation device known as the air-sparged hydrocyclone, shown in Figure 3, was developed (16). In this equipment, a thin film and swid flotation is accompHshed in a centrifugal field, where air sparges through a porous wall. Because of the enhanced hydrodynamic condition, separation of fine hydrophobic particles can be readily accompHshed. Also, retention times can be reduced to a matter of seconds. Thus, this device provides up to 200 times the throughput of conventional flotation cells at similar yields and product quaHties. 

Ferric hydroxide coprecipitation techniques are lengthy, two days being needed for a complete precipitation. To speed up this analysis, Tzeng and Zeitlin [595] studied the applicability of an intrinsically rapid technique, namely adsorption colloid flotation. This separation procedure uses a surfactant-collector-inert gas system, in which a charged surface-inactive species is adsorbed on a hydrophobic colloid collector of opposite charge. The colloid with the adsorbed species is floated to the surface with a suitable surfactant and inert gas, and the foam layer is removed manually for analysis by a methylene blue spectrometric procedure. The advantages of the method include a rapid separation, simple equipment, and excellent recoveries. Tzeng and Zeitlin [595] used the floation unit that was devised by Kim and Zeitlin [517]. 

Environmental regulations prohibit disposal of produced water without primary and. in some instances, secondary treatment. Corrugated-plate interceptors, cross-flow separators, flotation units and other specialized equipment is required to reduce hydrocarbon content to acceptable levels. Authors discuss various equipment used in water treating. Next month, equations and empirical rules to help the engineer select appropriate treating equipment wilt be provided. 

This research focuses on the induced-air flotation process for the removal of dispersed oil droplets. The industrial use of induccd-air flotation devices for oil wastewater separation began in IW9. Basset1 provides the process development history, equipment description, and operating experience lor an induced air unit similar to the design used in the experiments described here. Although induced-air flotation equipment is simple, the fluid mechanics of the process are not and the arrangement of the turbine, sleeve, and perforations have been determined necessarily by trail-and-crror experimentation with small-scale units. 

A simple and largely applied method for foam formation is dispersion of gas through porous plates (filters) placed at the lower parts of foam generation apparatus [5-10], This method is employed in flotation, in gas adsorption and dust collection in set-up with turbulent gas emulsion, and in the equipment for foam separation. The dispersity of a foam thus obtained depends on filter pore size or capillary diameter, hydrophility of the material used in the dispersion device construction, physicochemical properties of the foaming solution (surface tension, viscosity, surfactant concentration, etc.) and conditions of the dispersion process. 

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