FUNDAMENTALS OF THE FILTRATION PROCESS
Pressure-leaf filters, in either vertical or horizontal arrangement, provide excellent removal of suspended solids from a liquid. The slurry is introduced to the tank under pressure and is forced through the filter elements. Suspended solids are retained on the filter media. The clarified liquid flows to the interior of the leaf and is discharged to process. Solids are removed from the filter leaves and the unit is ready for another cycle. Even multiple filtering stations are normally a one-man operation. Filtering The unfiltered process liquid is pumped to the filter. The filtrate is directed to a storage and filtration continued until a full cake (3/4" to 1-1/2") is formed or flow diminished. If the solids are slimy in nature, it might be necessary to inject a filteraid slurry into the main feed line by means of a proportioning pump. What material is used in constructing filter leaves and media? Stainless steel, Monel, nickel, Carpenter 20, Hastelloy, titanium, plastic or whatever your application requires. Corrosion is a filters "worst enemy" and its potential effect on the filter and components must be considered from the start. Filter cloths, if needed, are available in metal, cotton or synthetic fabrics in a multitude of wave patterns and porosities. Solids loading Sizing is baed on the speed of solids buildp and the desired cycle time. The formula is figured:
Total solids per cycle (cu. ft.) = Required Filter Area (sq. ft.) Attainable cake thickness (ft.) The greater area figured from 1 and 2 (above) is the one to use. Cake thickness will also influence the spacing of leaves: Leaf Spacing Maximum Cake Thickness 2" * 3/4" 3" 1-1/8" 4" 1-1/2" * Not recommended for dry cake discharge filters.
Typical filtration applications: Edible Oils Rendering Potable Water Chemicals Tallow Resins Inedible Oil Lard Machine Oil Oil Additives Vinegars Condensate Beer Wine Waste Water Sugar Amines Juice Soda Fructose