Solid fluid separators

Solid-fluid reactions, 21 343-344 Solid-fluid separation, 22 52 Solid foams, 7 272t occurrences of, 7 273t Solid fuel combustion technology, 7 463-467... 

In solid—fluid separation, the fine particles are most difficult to separate, ie, Re is low, almost inevitably below 0.2, owing to low values of x and v. Therefore, only the Stokes region has to be considered. 

Owing to reduced salt solubility, the formation of metal oxides and, eventually, the presence of stable solid-matter particles, these are all present in the SCWO processes. These particles can cause equipment-fouling and erosion. However the reduced solubility of salts under supercritical conditions introduces the possibility of a solid fluid separation. 

R.C. Darton, (Ed.) Modeling of Solid-Fluid Separation, NATO Series, Ninjof New York, 1985. 

N,Hayashi. Y,Murakami. M,Shirato. et al. Proceedings of Thailand-Japan Joint Conference Solid-Fluid Separation Technology, P13, (1995)... 

Enzymatic reactions have been monitored by several procedures. In the case of solid-phase enzymes, analysis is best achieved by periodically withdrawing small aliquots of fluid-phase reaction medium, after solid-fluid separation has occurred via gravity settling (e.g., disabling the agitator in batch reactors), filtration, or centrifugation. The aliquot can then be analyzed via chromatography or spectroscopy. Water content... 

The conversions mentioned above are to be avoided whenever possible, because of inherent errors in such procedures, by using a method that would give the desired type of distribution directly. Different methods give different types of distributions and the selection of a method should be done on the basis of both the particle size and the type of distribution required. In common processing applications, for example, solid-fluid separations, it is the size distribution by mass that is usually of interest, because the separation efficiency is based on gravimetric means. There are, however, cases such as liquid clarification where turbidity of the overflow is of importance, and size distribution by surface or even by number would be more relevant. Figure 2.23 shows the four types of distribution in a diagram. 

The imperfection of separation generally observed in any device performing a solid-fluid separation operation, can be characterized evaluating some... 

Some other types of gravimetric efficiency have been reported in the literature. Although some of them would be quite specific, a general knowledge would be important due to the complexity of solid-fluid separation techniques. Svarovsky (1979) has given an exhaustive review of the general topic of separation efficiency in process engineering. 

According to Svarovsky (2000) the combination giving best results is that using both leaving streams in a solid-fluid separation process, that is, overflow and underflow, as represented by Equation 10.28. 

If, in order to practically assess the performance of solid-fluid separators, a reduced grade efficiency curve is used, the particle size which gives 50% efficiency in such a curve is called the reduced cut size and is represented by x o-The maximum attainable efficiency related to particle size would be that minimum particle size with 100% probability of being reported to the underflow. Graphically, by extrapolating the end part of the curve to the horizontal axis, such size will be obtained. It has been proved that in practice, the maximum of the efficiency is around 98%, and the minimum size corresponding to this efficiency is represented by Xgg and known as the approximate limit of separation. 

As a final note is important to bear in mind that solid-fluid separations are governed by mechanical forces, such as the gravity force, and so it is important that the screen analysis data on the relevant streams used to derive a grade efficiency curve had been measured avoiding transformations. The use of a particle sizer that measures the relevant particle size directly, that is, any method measuring directly the Stokes diameter should be preferred over a method relying on transforming size distributions from number to surface, or surface to mass, and so on. 

Murphree e3ctract stage efflciency, Murphree raffinate stage efficiency (6.4.70), (6.4.71) Murphree vapor efficiency (8.1.198) Newton particle separation efficiency (2.4.14a) total efficiency in solid-fluid separation (2.4.4a), overall Alter efficiency (6.3.45), (7.2.201) reduced efficiency of KelsaU (2.4.16a) Ej- for ith solid-fluid separator (2.4.17c,d)... 

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