Rotating disc filter

Kempken et al. [113] employed a rotating disc filter to harvest CHO cells, and observed that the filter could be operated at low transmembrane-pressure with high wall shear rates, leading to high filtrate flow rates, high product yields and minimum fouling. They concluded that their system offered a powerful alternative to conventional tangential flow filtration. 

Fig. 6. Rotating disc filter designed using computational fluid dynamics [114]...

Dynamic filtration modules are basically of two types rotating disc filter (RDF) and vortex flow filter (VFF). In the latter, the filtration module has a cylindrical shape and has a rotating concentric cylindrical mesh in its interior. The rotational movement of the internal cylinder generates a Taylor-Couette flow in the annular gap (Roth et al., 1997), creating Taylor vortices that minimize concentration polarization and mesh fouling. Continuous perfusion processes based on this type of filter and operating continuously for up to 100 days have been reported (Mercille et al., 1994). 

Rotating disc filter developed by Castilho and Anpach (2003). 

Bouzerar R, Jaffrin MY, Ding L, Pauher P. (2000) Influence of geometry and angular velocity on performance of a rotating disc filter. AICHEJ, 46 257-265. 

Continuous filtration is discussed by Coulson and Richardson.. It commonly employs rotary vacuum filters. These are usually cylindrical in shape, rotating about a horizontal axis with a filter medium on the curved surface and a vacuum applied from inside. Rotating disc filters are less frequently employed (see Fig. 2.4). These have a number of discs on the same shaft with vacuum applied from inside but the flat surfaces of the discs hold the filter medium. The methods of continuous discharge of the filter cake during operation, and of replacement of the filter medium at intervals, are less elegant than those applicable to rotating cylinders. 

Anaerobic reactor types 1, up-flow anaerobic sludge bed 2, anaerobic fluidized bed 3, anaerobic filter 4, anaerobic rotating disc 5, inclined tubular digester (6, pre-acidification tank)... 

Disc Filters A disc filter is a vacuum filter consisting of a number of vertical discs attached at intervals on a continuously rotating... 

Membrane filters include flat sheet, spiral wound, and hollow fiber (Fig. 23). In addition, there are also rotating discs, annual gap, and vibrating disc systems for membrane cross-flow filtration. 

Comments The sample and solvent were placed in a 100 ml screw-capped bottle and extracted on a rotating-disc Warburg mixer. The resultant sample/solvent mixture was filtered under vacuum, and the extracted sample then filtered through a 0.45. im membrane Acrodisk prior to analysis. 

KEYWORDS Rotrode Filter Spectroscopy (RFS), rotating disc electrode spectrometer, RDE, used oil analysis... 

A microscopic inspection of the carbon disc electrodes used in rotating disc electrode (RDE) spectrometers reveals that they are porous. Rotrode filter spectroscopy (RFS) makes use of this fact, and a fimnel-based fixture (Fig. 1) is used to clamp the discs so that used oil samples can be drawn through the outer circumference of the disc when a vacuum is applied. The filtering process through the disc captures the particles in the oil. The oil is then washed away with solvent, and the disc is allowed to dry. The particles are left on the outer circumference of the disc electrode so that they are v otized and detected when sparked on the RDE spectrrxneter. 

Rotating disc electrode spectrometer, 71 Rotrode filter spectroscopy, 71 Round robin test, 128... 

Lukas et al. Spectro /nc.) describe an improvement made in rotating disc electrode atomic emission technology by incorporating a filter device in the rotrode, which enables to detect particles greater than 10 pm size. 

In a variant the rotating discs are omitted and the circular filter elements themselves, which are double-sided and mounted on a hollow shaft, are caused to rotate. With some types a second, counter-rotating, set of filter elements overlaps the peripheries of the first set to further enhance shear at the... 

Horizontal- or vertical-vessel filters with vertical rotating elements in particular have been under rapid development recently with the aim of making truly continuous pressure filters, particularly, but not exclusively, for the filtration of fine coal. There are basically three categories of continuous pressure filters presently available disc filters, drum filters and belt filters, the last category including both the hydraulic and compression varieties. For the purpose of this review, we shall also briefly consider some semi-continuous, indexing cloth filters and other types with intermittent movement of elements. Only those filters which discharge the solids in the... 

Another development of the disc filter has been reported more recently from KHD Humboldt Wedag AG . A somewhat different system, probably a predecessor, was also patented by the same company. The patented sys-tem has stationary discs mounted inside a pressure vessel (horizontal vessel, vertical discs) which is mounted on rollers and can rotate slowly about its axis. A screw conveyor is mounted in the centre of rotation but this is stationary it conveys the cake, which is blown-off the leaves when they pass above the screw, to one end of the vessel where it falls into a vertical chute. The cake-discharge system involves two linear slide valves which slide the cake through compartments which gradually depressurize it and move it out... 

The filter discs consist of a number of sectors. Their number is dependent among other things on the diameter of the discs. The individual sectors have a grooved and/or perforated surface, which is covered both sides with the filter cloth. The discs rotate in the disc-filter trough and during one revolution, they go through one complete filtration cycle. Via the filtrate pipe system accommodated... 

An interesting extension of the range of vacuum filters is the capillary disc filter (Figure 4.26). This is a continuously operating, capillary action, ceramic dewatering filter, which eliminates the need for separate filter cloths. The filter medium is a disc, formed from two circles of sintered alumina, joined at their circumferences. The filter has several such discs mounted on a central horizontal shaft. The medium is practically inert in most solutions, and may be used in a broad range of water-based and solvent-based slurries. In operation, as the microporous ceramic discs rotate through... 

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