Centrifuge types, sedimenting

Postrenal Proteinuria. This type of proteinuria refers to protein arising from the urinary tract below the kidneys and is usually due to inflammation or malignancy. It is diagnosed by microscopic evaluation of the urinary sediment for inflammatory cells and malignant cells. The presence of erythrocytes or leukocytes in casts in such a centrifuged urinary sediment is valuable proof that their origin is from the kidneys and is not extrarenal. 

Equation 8 provides the basis of comparison for the performance of various bottle centrifuges having the same material, and also, under certain circumstances, of other types of sedimentation centrifuges, if geometric dissimilarities are also considered. 

The Z-concept permits scale-up between sinulat centrifuges solely on the basis of sedimentation performance. Other criteria and limitations, however, should also be investigated. Scale-up analysis for a specified sohds concentration, for instance, requires knowledge of sohds residence time, permissible accumulation of sohds in the bowl, G level, sohds conveyabihty, flowabihty, compressibihty, limitations of torque, and sohds loading. Extrapolation of data from one size centrifuge to another calls for the apphcation of specific scale-up mechanisms for the particular type of centrifuge and performance requirement. 

Purchase Price Typical purchase prices, including drive motors, of tubular and disk sedimenting centrifuges are given in Table 18-16. The price will vary upward with the use of more exotic materials of construc tion, the need for explosion-proof elec trical gear, the type of enclosure required for vapor containment, and the degree of portability, and this holds for all types of centrifuges. 

Classifier types fall into two basic categories (1) gravitational and (2) centrifugal classifiers. Gravitational classifiers can be subdivided into (1) sedimentation and (2) hydraulic classifiers. Furthermore each type falls into mechanical and nonmechanical types. 

There are many different types of centrifuges, classified according to the way in which the transport of the sediment is handled. The... 

A variety of centrifugal filter and sedimenter designs is used. The main types are listed in Table 10.5. They can be classified by a number of design and operating features, such as ... 

There are four main types of sedimentation centrifuge ... 

A selection guide for sedimentation centrifuges by Lavanchy et at. (1964), which includes other types of solid-liquid separators, is shown in Figure 10.19, adapted to SI units. 

In natural waters and soil and sediment systems one needs to distinguish analytically between dissolved and particulate material. Fig. 7.1 classifies various types of particulate and dissolved materials. Obviously, operational distinguishing (e.g., based on filtration or centrifugation) between "dissolved" and "particulate" matter merely by filtration is often not able to discriminate between particles and solutes, because size distribution of aquatic components vary in a continuous matter from Angstroms to microns. 

Regardless of the rotor speed and maximum velocity, sedimentation (or flotation) will not occur in a solution of equal density to the sample. Iso-density methods use this lack of movement in a manner comparable to a pH gradient in iso-electric focusing techniques. The methods are a combination of sedimentation and flotation, achieved by using a density gradient that straddles the density of the particles concerned. On centrifugation, the particles sediment until they reach a solvent zone with the same density. This results in the development of a zone for each type of particle present in the sample. 

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