Oliver filter

The rotary-drum suction filter is possible only because of the automatic valve, which places a compartment under suction alternately for filtrate, for wash, and blowback for bulge. The valve is described on p284 and shown in Fig 227 of Ref 1. A detailed cross section of Oliver filter is given in Fig 77, p977 of Ref 2, which includes a table with a complete list of parts... 

Other types of Oliver filters include the top-feed filter (Ref 2, p980, Fi g 82) and its modification by Robinson (Ref 2, p980)... 

The Portland filter is built in drum sizes of 6, 8, 12 and 14 ft. diameter and with various width of face up to 16 ft. The Oliver filter is built in the following sizes of filter drum ... 

The Oliver precoat filter is a modification of the regular Oliver filter. It consists of a horizontal cylindrical drum, the outside pf which is made up of separate segments or compartments. The entire outside of the cylinder is covered with a filtering medium such as fine mesh wire or cloth. Each segment is connected to a discharge line, under vacuum, by a special valve on the end of the drum in such a way that suction is maintained while the drum rotates. A deposit (or precoat) of diatomaceous earth or Ref. Nat. Oaso. Mfr., February, 1934, p. 54. 

FIG. 18-126 Operating method of a vacuum precoat filter. (DotT-Oliver, Inc. )... 

Four neutral lipid models were explored at pH 7.4 (1) 2% wt/vol DOPC in dode-cane, (2) olive oil, (3) octanol, and (4) dodecane. Table 7.5 lists the effective permeabilities Pe, standard deviations (SDs), and membrane retentions of the 32 probe molecules (Table 7.4). The units of Pe and SD are 10 6 cm/s. Retentions are expressed as mole percentages. Figure 7.22a is a plot of log Pe versus log Kd (octanol-water apparent partition coefficients, pH 7.4) for filters loaded with 2% wt/vol DOPC in dodecane (model 1.0, hlled-circle symbols) and with phospholipid-free dodecane (model 4.0, open-circle symbols). The dashed line in the plot was calculated assuming a UWL permeability (see Section 7.7.6) Pu, 16 x 10-6 cm/s (a typical value in an unstirred 96-well microtiter plate assay), and Pe of 0.8 x 10-6 cm/s... 

The mixture is then chilled in an ice bath for at least 3 hours, and the olive-brown precipitate of the sparingly soluble copper complex of imidazole derivatives is filtered. The product is washed with about 500 ml. of cold water, suspended while moist (Note 4) in 11. of water, and rendered just acid to litmus by the addition of concentrated hydrochloric acid (about 40 ml.). Hydrogen sulfide is then passed into the suspension, with frequent shaking, until precipitation of the copper is complete (2-3 hours). The precipitate is filtered and extracted with 500 ml. of hot water in two or three portions. The clear, light brown to reddish brown filtrate and washings are boiled for 15 minutes, and then 60 g. (0.26 mole) of picric acid is added with stirring heating is continued until solution is complete. 

Extract was prepared from the leaves and roots of two years old olive plants with water at room temperature. Internal standard as D-3-0-methylglucopyranose(MeGlu) was used and added In appropriate volume. Extraction was accomplished by shaking for 15 min and finally the suspension was centrifuged at 3000 rpm for 10 min. Before the injection the aqueous phase was filtered and passed on a cartridge OnGuard A (Dionex)to remove anion contaminants. 

To a solution of 8 gm (0.05 mole) of 2-amino-3-naphthol (m.p. 225°C) in 100 ml of benzene is added 6 gm (0.05 mole) of thionyl chloride. The mixture is refluxed for 3 hr. The reaction mixture is then cooled and filtered through a fritted-glass funnel. The filtrate is evaporated to dryness to leave 4 gm of an olive-brown residue of the hydroxythionylnaphthylamine (yield 30%). 

Dorrco Continuous Suction Filter has, in contrast to Oliver, its filtering surface on the inside of the drum, and the suction line on the outside. It is described by Riegel (Ref 1, p287—88 Fig 232) and by Perry (Ref 2, p979 Fig 81)... 

The amount of acid required varies with dryness of the filter cake. The acidification can be followed by observing the color of a thin layer of the solution splashed against the side of the container. The color changes from dark red to olive brown at the end point. Both colors are so deep that they are not easily distinguished except when thin layers are viewed. After the end point is observed, an additional 10 ml. of acetic add is added. 

Figure 11.11. Continuous horizontal vacuum filters especially suited to free settling and draining solids, (a) Principle of the conveyor belt filter units may operate up to 0.S m/sec with a cycle time up to 10 min and produce cake thicknesses up to 15 cm. (b) Showing the construction of a grooved rubber belt support for the filter cloth of the belt filter (Purchas, 1981). (c) Rotating horizontal vacuum filter the unit has readily accessible piping and is amenable to thorough washing of free draining solids (Dorr-Oliver Inc.).

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