Centrifuges imperforate basket centrifuge

Tubular centrifuge Multichamber centrifuge Imperforate basket centrifuge Scroll-type centrifuge Disc centrifuge... 

Imperforate basket centrifuges are vertical baskets that make up a relatively small portion of those sold. They are most often used to collect fine or amorphous solids, especially slimy or sticky ones. The solids are fed into the basket and those that are heavier than the liquid accumulate on the wall, much as they do in the tubular bowl. Because the diameter of the basket is at least an order of magnitude larger than that of the tubular bowl, there is usually space for a discharge mechanism inside the basket. Imperforate bowls often have two instruments a skimmer for liquids and a plow for solids. The clear, less dense liquid supernates... 

The relatively new arrival, the Powerfuge by Carr Separations Inc. described in section 7.5, has also proved to be suitable for classification of superfine solids. An interesting study on the flow and its effects on classification in the Powerfuge has recently been published by Kessler and Kremer. They followed on some earlier flow visualization studies in imperforate basket centrifuges that concluded that the flow in these machines was quite distinct from plug flow and instead assumed the form of a boundary layer on the pool surface . At the 1999 AFS Technical Conference, Beiser et al. presented results of a study of residence time distribution (RTD) in a decanter centrifuge. They concluded that the flow was best modelled by CSTRs in series or plug flow with axial dispersion. 

The Imperforate Bowl Centrifuge. In an imperforate bowl centrifuge the dow of the continuous Hquid phase is nominally axial, except for areas immediately adjacent to the feed inlet and efduent oudet. Tubular soHd-bowl basket and imperforate bowl conveyor-discharge centrifuges satisfy this definition. 

For the sepn of solids from liquids, there are two types of centrifuges a)Solid wall(such as imperforate basket type) centrifuge, in which sepn or concn is by subsidence or flotation and b)Perforated wall(such as perforated basket type) centrifuge in which the solid phase is supported on a permeable surface thru which the fluid passes. A 3rd type is a combination of a) b) above. Here the primary concn is achieved by subsidence, followed by drainage of die liquid phase from the solid phase. These centrifuges can be either of batch or continuous operations. For sepn of liquids, there are bottle and tubular centrifiiges(Ref 2, 8,10,12,14,16,19,20,21,23,25,26 27)... 

Sedimenting centrifuges use a solid/imperforate bowl to enhance sedimentation. The most common sedimenting centrifuges listed in the order of decreasing G-level, are as follows tubular bowl, disk stack separator, decanter, and imperforate baskets. 

This is an adaptation of the standard basket centrifuge used for centrifugal filtration made by replacing the bowl with an imperforate one. 

FIG. 18-138 Principl es of centrifugal separation and filtration (a) sedimentation in rotating imperforate bowl (h) Bltration in rotating perforate basket. 

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