Plate filter press

Screw-pressed oil is aUowed to stand to settle out suspended soUds, filtered through plate filter presses, and then pumped to storage. The oil-rich solvent (miscella) from the solvent-extraction process is filtered or clarified, and most of the solvent is removed in a long tube evaporator. FinaUy, the concentrated oil passes through a stripping column where sparging steam is injected to remove the residual solvent. A metric ton of cottonseed yields ca 91... 

Recessed-plate filter press. This press is similar to the plate-and-frame press in appearance but consists only of plates (Fig. 18-113). 

Concentrated metal hydroxide sludge is pumped from the clarifier to a polypropylene plate filter press [T-102], The plate filter press56 is of sufficient capacity without any buildup in the lamellar portion of the unit. This also prevents any overflow of precipitate to the sewer system. The metal hydroxides form a dense sludge cake suitable for disposal in an approved landfill. The liquid effluent from the plate filter is returned to the surge tank [T-99],... 

Membrane Filter Press. Membrane filter presses use impermeable, flexible membranes, or diaphragms to squeeze the cake for further cake deliquoring, as shown in Fig. 15. This type of filter provides less dead time in a filtration cycle, better washing, and drier cake compared to traditional plate-and-frame and recessed plate filter presses. A comparison of a recessed press operated at 100 psi and a membrane filter operated at 25psi for sludge dewatering is shown in Table 4. ... 

Recessed-plate filter press. This press is similar to the plate-and-frame press in appearance but consists only of plates (Fig. 18-126). Both faces of each plate are hollowed to form a chamber for cake accumulation between adjacent plates. This design has the advantage of about half as many joints as a plate-and-frame press, making a tight closure more certain. Figure 18-127 shows some of the features of one type of recessed-plate filter which has a gasket to further minimize leaks. Air can be introduced behind the doth on both sides of each plate to assist cake removal. 

FIG. 18-126 Automated recessed-plate filter press used in mineral applications. (Dorr-Oliver EIMCO.)... 

FIGURE 58.3 Recessed-plate filter press. (From Shirato, M. etal.. Filtration—Principles and Practice, eds. M. J. Matteson and C. Orr, Marcel Dekker, New York, pp. 299—423,1987. With permission.)... 

The smelter treats all of the zinc plant residues, which constitute approximately 45-50% of the charge. The percentage of zinc plant residues is a function of the smelter elemental limits and maintains a specific heat balance in the KIVCET furnace. Residues fiom the oxide leach plant and sulphide leach plant are blended and pumped to the feed plant at a specific gravity of 1.75. The residues are filtered through two Ingersoll-Rand Lasta plate filter presses. The total residue filtering capacity is 825 dry t/d, with the filter cake containing 20-22% moisture. 

Figure 11.27 Shriver recessed plate filter press plate shifier and washer (Bunco Process Equipment Co.,...

Multi-element candle Multi-element leaf Plate frame press Precoat Nutsche and multielement leaf Precoat plate frame press Recessed plate filter press Sheet filter Single leaf Nutsche Bag Cartridge Dead-end membrane Fibre bed Low shear crossflow Sand bed Simplex strainer Belt press Duplex strainer High shear crossflow Rotary disc Rotary drum Sand bed Tower press Diaphragm filter press Expression (screw) press Horizontal element tube press Vertical diaphragm filter press Vertical element tube press... 

Ftmctional lest of the black boxes Self-contained and operative small plants such as e.g. dosing plants, plate-and-recessed-plate filter presses, vacuum pumps with peripheral devices etc. are called black boxes . The functional test comprises the testing of individual functions with the system being empty. 

Operation of the recessed plate filter is much the same as that described above for the plate and frame filter. Some degree of mechanization of the solid discharge process has been achieved, leading to a measure of automation in the operation of a recessed plate filter press. 

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