Hydrocyclones multiple

The method EBC patented essentially for achieving oil-water separation was based on hydrocyclones [267], In this design, the fact that an oil-loving biocatalyst such as Rhodococcus tends to partition at the oil-water interface was made use of. The separation was achieved by controlling the phase ratio and operating in sequential steps using multiple hydrocyclones. 

Figure 6.22 Types of multiple hydrocyclone arrangements, (a) Plan view (b) Elevation (c) Plan view (d) Plan view (e) Cross-section...

In the case of really small cyclones (e.g. 10 mm diameter units), these are sometimes cast into disks and such disks are stacked into columns. Such systems resemble other chemical engineering columns for mass transfer or cartridge systems for filtration. One problem common to all compact multiple hydrocyclone systems is with the operator s inability to see any blockages. He or she must then diagnose any such difficulties from other operating performance such as an increase in pressure drop. Having detected a blockage problem, the only remedy available is to replace the unit or the whole column and clean it off-line. 

Hydrocyclones are available in numerous sizes and types ranging from pencil-sized 10-mm diameters of plastic to the 1.2-m (48-in) diameter of rubber-protected mild or stainless steel. Porcelain units 25 to 100 mm (1 to 4 in) in diameter are becoming popular, and in the 150-mm (6-in) size the starch industry has standardized on special molded nylon types. Small units for fine-size separations are usually manifolded in multiple units in parallel with up to 480 ten-mm... 

The existing titanium hydrocyclones are close in design to the units to be provided by the Mozley Company for a full-scale facility in multiple parallel flow units (sometimes called multiclones ). Therefore, the results for the titanium system are anticipated to be similar to those for the Mozley units. 

Demonstrations of the scale-up, development, and integration of hardware with real materials of construction must focus on the robustness of the parallel flow in multiple-cell reactors. The issues of cell blockage, hydrocyclone performance, and NOx reformer performance must be addressed. 

Units are sometimes placed in series to provide multiple stages of separation. Hydrocyclones are used on ships and drilling platforms for removing oil from water [Bednarski and Listewnik, Filtration and Sep., pp. 92-97 (March/April 1988)]. Numerical simulations ofhydro-cyclone performance and flow profiles are described by Bai and Wang [Chem. Eng. Technol., 29(10), pp. 1161-1166 (2006)] and by Murphy et al. [Chem. Eng. Sci., 62, pp. 1619-1635 (2007)]. 

It is apparent that high retention efficiency of solids, i.e. a low cut size, is given by a hydrocyclone of low diameter. This inq)oses limitations on the throughput of the device. It is, therefore, common to encounter multiple installations of hydrocyclones with many... 

Hydrocyclones In the range of 80-90% External Shear damage due to vortices interaction Good Possible Robust static device. No special maintenance required Well established designs from reputed manufacturers Multiple cyclones in parallel are a feasible altemalive. High harvest rates/ smaQ cyclones result in shear damage... 

In order to make use of the high efficiency of separation of small diameter hydrocyclones, most manufacturers offer multiple arrangements of varying design. Series arrangements, with or without recycles, can be used to improve any performance characteristic of hydrocyclones, see chapter 16. 

In order to make full use of the advantages of the hydrocyclone it is often best to use multiple units, connected either in series or in parallel. In clarification duties for example, the parallel connections allow the more efficient, smaller diameter units to be used to treat high flow rates. The series connections on the other hand, are used to improve overall recoveries in clarification, to produce thicker underflows and clearer overflows simultaneously, to wash solids or to sharpen the classification or sorting. 

Series connections of separators are a common way of improving the performance of single units. In the case of hydrocyclones, due to their low capital and running costs, multiple series arrangements are quite frequently used. As to which particular layout and arrangement should be used depends on the actual application in question. 

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