Filter cloth fine

The scraper or knife discharge consists of a blade that removes the cake from the dmm by direct contact with the filter cake. It is normally used for granular materials with cake thickness greater than about 6 mm. In order not to damage the filter cloth, a safety distance of 1 to 3 mm between the blade and the cloth must be observed. If the residual layer is made not of filter aid but of the product, there is danger of its blocking by fine particles and by successive consoHdation by the scraper blade. 

Blinding of the filter cloth by fine particles or slimes is reduced. Surfactants are also used to enhance flow through the filter cake pores. 

The seedlac may then be converted to shellac by either a heat process or by solvent processes. In the heat process the resin is heated to a melt which is then forced through a filter cloth which retains woody and insoluble matter. In the solvent process the lac is dissolved in a solvent, usually ethyl alcohol. The solution is filtered through a fine cloth and the solvent recovered by distillation. 

Filtrates that are acceptable with a low quantity of fines that pass trough the filter cloth in the first few seconds of cake formation. Broadly, and depending on particle size and cloth permeability, the filtrate may contain 1,000 to 5,000 ppm insolubles. 

Figures 4-65, 4-66, and 4-67 show several units of the bag. The bags may be of cotton, wool, synthetic fiber, and glass or asbestos with temperature limits on such use as 180°F, 200°F, 275°F, 650°F respectively, except for unusual rnaterials. (See Table 4-12A and B.) These units are used exclusively on dry solid particles in a gas stream, not being suitable for wet or moist applications. The gases pass through the woven filter cloth, depositing the dust on the surface. At intervals the unit is subject to a de-dust-ing action such as mechanical scraping, shaking or back-flow of clean air or gas to remove the dust from the cloth. The dust settles to the lower section of the unit and is removed. The separation efficiency may be 99%-i-, but is dependent upon the system and nature of the particles. For extremely fine particles a precoat of dry dust similar to that used in some wet filtrations may be required before re-establishing the pi ocess gas-dust flow.

Once brine shrimp have hatched, collect them in a coffee filter, cloth, or fine strainer and rinse them gently with fresh water. At this time the newly hatched shrimp can be placed into a small tank or fed directly to the fish. 

If not removed, the boric acid makes extraction of the product impossible or very difficult. Since the boric acid is finely divided, filtration is extremely slow unless large Buchner funnels, preferably with large holes, are employed. The checkers avoided the difficulty by using a filter cloth at this point. 

In the filtration process, a liquid containing suspended solids is passed through a porous medium. The solids are trapped against the medium, and the separation of solids from liquids results. For large solid particles, a thick barrier such as sand may be used for smaller particles, a fine filter such as a filter cloth is preferable. Fluid passage may be induced by gravity, positive pressure, or a r acuum. A few of the more popular filter fypes are the plate and frame filter press, and shell and leaf and cartridge filters. 

The open-tank suction filter is particularly adapted to cases where the amount of solids to be handled is only a small percentage of the total bulk where the solids are very finely divided and where the cake takes a long while to build. There is but little wear on the filter cloth, and the cake builds to an even resistance, so that it washes evenly and with a minimum of washing. 

Filtering through Muslin. — Precipitates which are not too finely divided may be filtered off through a filter-cloth (muslin) stretched over a wooden frame (filter-fra me) (Fig. 42). A square piece of muslin or linen, after being thoroughly moistened, is... 

Filter cloth is commonly used for dressing a filter, although for some applications, fine mesh wire screen or paper is appropriate. The real function of the filter cloth or other membrane is to furnish a support for the real filter medium, namely, the bed of deposited solids that form the filter cake. The ability to maintain maximum flow of clear filtrate depends on furnishing a filter cake of proper permeability. 

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