Coarse filtration

Crushed stone or brick is used for coarse filtration of particularly corrosive liquors. Their use, however, is extremely limited and they are not considered important filter media. 

When glass fiber paper tape is used, this can be strengthened by the application of a rubber solution along each edge, or with an under tape of strong filter paper having coarse filtration properties. After drying, the tape must be sealed on the upper surface with transparent cellulose tape. 

The hot wort is first lautered, a coarse filtration step, by passing it into a vessel with a perforated false bottom (lauter tun), which retains any undissolved grain, malt, and husk fragments. Filtered wort is then boiled for a period of 2-3 hr, hops being added after the first hour, usually in several small portions. Hops, which consist of the bracteole or cone of a vine Humulus lupulus provide the characteristic bitter flavor component of a beer. These are contributed by several humulones and related compounds [11, 12] (Eq. 16.7), which are extracted from the hops during this boiling step. 

There are three (3) types of pharmaceutical filtrations depth, cake, and membrane. Cake and depth are coarse filtrations, and membrane is a fine, final filtration. Membrane filtration and cross-flow filtration are discussed in Ch. 7. 

HusUti filters ore only used for coarse filtration. 

Microfiltration (MF) is the most common pressure-driven membrane separation process and also the easiest to understand [1, 2]. It is simply conventional coarse filtration running at very low pressures (typically below 2 bar) owing to the open structure of the membranes. Darcy s law is apphcable showing a proportionality between the appHed pressure difference AP and the flux J through the membrane. 

Designing the process of the reuse of osmotic solution the coarse filtration, pasteurization, and decolorization must be taken into account. The sanitation of the solution is a priority in the recycling process. 

An integrated membrane plant used for treating produced water from an oil well is shown in Figure 3.4 [10]. Coarse filtration of raw water is treated by dissolved gas flotation to reduce suspended soHds and oil/grease. Pre-treated water (TDS = 10,000 mg/1) is treated in a multi-step membrane process followed by ion exchange (IX) ... 

The water available from freshwater sources may require treatment before it can be used domestically. The several steps generally used in municipal water treatment include coarse filtration, sedimentation, sand filtration, aeration, sterilization, and sometimes water softening. 

Typical uses Coarse filtration of very dilute suspensions. 

Microfiltration is the membrane process which most closely resembles conventional coarse filtration. The pore sizes of microfiltration membranes range from 10 to 0.05 p.m, making the process suitable for retaining suspensions and emulsions. 

The water needed for domestic uses, agriculture, and industrial processes is taken from naturally occurring lakes, rivers, and underground sources or from reservoirs. Much of the water that finds its way into municipal water systems is "used" water it has already passed through one or more sewage systems or industrial plants. Consequentiy, this water must be treated before it is distributed to our faucets. Municipal water treatment usually involves five steps coarse filtration, sedimentation, sand filtration, aeration, and sterilization. Figure 18.17 T shows a typical treatment process. 

Municipal water treatment usually involves five steps coarse filtration, sedimentation, sand filtration, aeration, and sterilization. 

Metafiltration n Edge filtration through superimposed metallic strips with beveled edges, involving a change from coarse filtration (due to the strips) to fine filtration (due to the filter bed formed in their interstices). 

There are two major appUcations for which these metallic media are primarily used the separation of solid particles by size, and the coarse screening of gas or liquid flows ahead of some finer processing stage. In the coarser, macrofiltration processes these are very versatile materials all of the dry classification (sieving, sifting) operations are covered here, as are almost all of the applications of filters for straining and coarse filtration, both of which rely upon the precise size and shape of the apertures in the mesh or sheet. 

Perforated plate strainers provide coarse filtration down to about 150 pm. For finer filtering, wire mesh elements are normally used in conjunction with perforated plate or other form of reinforcement, when this is necessary for added mechanical strength. Nfire mesh strainers can provide filtration down to about 40 pm, but with reduced strength due to the increasingly fine wire used. 

Gelatine liquor usually involves a multi-stage filtration process. Primary filtration removes coarse particles of suspended matter, and secondary filtration further improves the clarity and imparts a brilliance to the liquor. Where the gelatine liquors are to be passed through ion exchange columns, coarse filtration takes place before the deionization stage. The primary operation is best accomplished with kieselguhr as the... 

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