Rotary disc filter

Rotary disc vacuum filters have the advantage, compared with rotary drum filters, of giving a much larger filter area per unit of floor area. They are thus particularly suitable for the processing of bulk products, for example in coal preparation, ore dressing, pulp and paper processing, and so on. 

The principle of construction of a rotary disc vacuum filter is that a number of filter discs are mounted, parallel to one another, on a horizontal shaft. Each disc 

The filter area, and thus filtering capacity, of a rotary disc filter can be increased by increasing the number of discs in the complete unit. Standard units available may have from one to twelve or more discs, and tend to be made of plastic material. Each disc in turn may have up to 30 filter cells depending on the filter s diameter. Drainage tubes are large and mounted outside the shaft. 

Drum channels designed to withstand the tens of miiiions of pressure/vacuum cycies to which they are subjected 

Vaive disc programmed for optimum pressure/vacuum cycies 

It ould be noted that Ft (used m European sugar industry calculations) is defined by  

In these unbs, as with drum fibers, the feed suspenaon is supplied continuousH into trouts, in which the liquor flow is arranged in the same direction as the rotating di s. The latter move at various speeds, in the range 0.5-3.5 ipm. Submeigences up to 50% of the fibering sur ce can be arranged by level control Disc fibers are available in areas fix m 0.5-300 

Improved disc filter operation has been obtained with a disc design containing 30 segments instead of 12 and gave capacity increases of 10%. A hi er operational speed was permitted with the new design leading to a 35% increase in productivity. These practical resubs have been predicted in a theoretical model of the disc fiber [Ru on, 1974] which allows for the 

Technical brochure information rarely reports the baas of cake moisture. Laboratory tests on the latter [Bosley, 1986] involve carefid sampling of the wet cake weired quantities of the latter are dried at 105°C to constant dry weight. The amount of hquor evaporated is then ejqrressed as a percentage of the wet (or dry) cake. In the table below, a wet baas is assumed. 

Where such a read in size exists, and vhere doth blinding effects are prevalent, particle classification of the feed prior to filtration may prove barefidal As outlined in Chapter 4, an ahemative is to allow passage of the fine matoial in the eatfy stages of a s aration these fore-runnings may then be recycled to the filter. 

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Figure 11.5 Rotary disc filter (Courtesy of Gaudfiin SA, St. Germaine-en-Laye, France)...

It is also observed that filter cake washing effidencies can be low in these filters. Such effects are attributed to maldistribution of wadi water sook of the latt inevitably cascades over the cake sur ce, to be collected in the feed trou As befine, the limited time for washing is also a problem. In some cases, two stages (or nmre) of fihrarion may be conddered, wiffi intat age, re-duiry washing. Ibese con onents also appfy to rotary disc filters discussed in the next section. 

Rotary disc filters are available at a relatively low capital cost with total cloth areas between 0.05 and 300 m. They have an inherently large filter area to floor space ratio and their flexibility is enhanced by an ability to process multiple feedstocks at the same time within a single unit. 

Satin 9000 340 660 Belt, drum and rotary disc filters, filter press, centrifuge... 

Rotary Disc Filter Rotary Table Filter Rotary Tilting Pan... 

The rotary disc filter cycle as shown in Figure 7.5 is restricted to single cake formation and deliquoring phases (see also Section 1.4.1.6). Due to the vertical... 

Figure 7.5 Schematic diagram of a rotary disc filter cycle showing the end view of one disc only typical installations comprise multiple discs mounted on a common central shaft. Suspension is fed into the trough at an appropriate position along its length.

Finally, the rotary disc filter can also be enclosed in a pressure vessel and operated under pressure and this is the idea behind most of the continuous... 

Coagulants and flocculants can enable a more open, faster medium to be employed, and still retain fines capture, thus providing an increase in throughput whilst achieving acceptable cake moisture contents [24,25]. Examples of rotary drum filters and rotary disc filters are shown in Figures 6.15 and 6.16 respectively. 

Figure 6.16 Rotary disc filter. Published by kind permission of Peterson Filters Corporation.

A. Introduction 3B. Strainers 3C. Screens 3D. Nutsche filters 3E. Tipping pan and table filters 3F. Rotary drum filters 3G. Rotary disc filters 3H. Horizontal belt filters Centrifugal filters Pad and panel filters 3K. Bag, pocket and candle filters 3L. Cartridge filters... 

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