Clarification filtration

The production of heers and ciders requires the fermentation of sugary fluids hy the action of yeasts, and the cooling, filtration, clarification and storage of the resulting alcohol-water mixture. 

Representative applications Sterile filtration Clarification/sterilization of beer and Representative applications Continuous culture/cell recycle Filtration of oilfield produced water... 

The containment cells are shielded on the front, back, ends, and top by concrete blocks. There is no shielding between containment enclosures. Wall thickness of the blocks is approximately 0.99 m. Shield windows are installed in the front face of the containment enclosures. The inner plate is 2.54 cm radiation-stabilized glass the outer plate is 2.29 cm Pyrex borosilicate glass. Space between these plates is filled with 0.91 m water, which circulates continuously through a filtration-clarification system. Manipulators are mounted in concrete filled lintels. Concrete blocks, totaling 0.77 m thickness, shield the top of the facility. 

Membrane pore size rating refers to the size of a specific particle to be retained by the filter with a specific degree of efficiency. Pore size will affect the flow rate, back pressure, and life of the filter. Membrane pore size is outlined in Table 9 and selected on the basis of the applications requirements. The size and amount of particles to be filtered from the sample can also affect the pore size selection. Most applications in the isolation of drug impurities and degradants would either require prefiltration to remove large clumps of insoluble excipients or a filtration/clarification step prior to FIPLC, and would be chosen on these bases.71... 

With the exception of the precoat applications, RVF s do not usually yield absolutely clear filtrate. Although still widely used, rotary vacuum filters are, in some cases, being replaced by membrane separation technology as the method of choice for clarification of fermentation broths and concentrating cell mass. Membranes can yield more complete filtration clarification, but often a wetter cell paste. 

Microfil- tration Symmetric micro-porous polymer membrane. Pore size 0.05-10 ym Hydrostatic pressure 1-5 bar Sieving mechanism, pore si2e and particle diameter determine separation characteristics Sterile filtration, clarification, cell harvesting bacteria, viruses separation. 

For the treatment of raw water into drinking water the following processes are used mechanical pre-treatment, sedimentation, filtration, clarification, removal of carbon dioxide, iron and manganese, adsorption on activated carbon and processes ensuring its suitability from the aspects of hygiene [6, 7]. 

A wide variety of screens and meshes are available, ranging from fine photoetched or electroformed perforated screens to the heavy duty wedge wire screens used in centrifuge and high pressure screw press construction. Simple sieves and coarse screens were used as early as the sixteenth century for processing metal ores. Modern woven wire screens are precision made cloths with aperture sizes as small as 20 pm (smaller aperture sizes are supplied by some manufacturers) for industrial separations in filtration, clarification and extraction. Plastic meshes and plastic coated metal meshes are finding an increasing number of applications in separation processes. 

Microfiltration Symmetric microporous membrane, 0.1 to 10 pA pore radius Hydrostatic pressure difference, 0.1 to Ibar Sieving mechanism due to pore radius and adsorption Sterile filtration clarification... 

For water to be used commercially, label each of the following as external treatment (ex) or internal treatment (in) () aeration, () addition of inhibitors to prevent corrosion, () adjustment of pH, () filtration, () clarification, () removal of dissolved oxygen by reaction with hydrazine or sulfite, and () disinfection for food processing... 

Rotary vacuum drum and vacuum belt filters are extensively used on many process filtration operations, to provide filtration, clarification, dewatering or concentration. Moulded thermoplastic vacuum drum filters are particularly suited to providing continuous... 

Although it is sometimes encouraged in white wines, particularly barrel-fermented Chardonnay, this fermentation tends to lower fmitiness and be considered undesirable in other white wines unless acidity is too high. This is also tme for pink and light red wines. If it occurs after bottling, a gassy, cloudy wine results. In such wines, it can be avoided by careful attention to clarification or filtration sufficient to remove the bacteria, by adding SO2 at appropriate intervals as an inhibitor, or by pasteurization. 

The trend in the use of deep bed filters in water treatment is to eliminate conventional flocculators and sedimentation tanks, and to employ the filter as a flocculation reactor for direct filtration of low turbidity waters. The constraints of batch operation can be removed by using one of the available continuous filters which provide continuous backwashing of a portion of the medium. Such systems include moving bed filters, radial flow filters, or traveling backwash filters. Further development of continuous deep bed filters is likely. Besides clarification of Hquids, which is the most frequent use, deep bed filters can also be used to concentrate soflds into a much smaller volume of backwash, or even to wash the soflds by using a different Hquid for the backwash. Deep bed filtration has a much more limited use in the chemical industry than cake filtration (see Water, Industrial water treatment Water, Municipal WATERTREATiffiNT Water Water, pollution and Water, reuse). 

In the precoat and body feed mode, filter aids allow appHcation of surface filtration to clarification of Hquids, ie, filtration of very dilute suspensions of less than 0.1% by volume, such as those normally treated by deep bed filters or centrifugal clarifiers. Filter aids are used in this mode with pressure filters. A precoat is first formed by passing a suspension of the filter aid through the filter. This is followed by filtration of the feed Hquid, which may have the filter aid mixed with it as body feed in order to improve the permeabiUty of the resulting cake. The proportion of the filter aid to be added as body feed is of the same order as the amount of contaminant soHds in the feed Hquid this limits the appHcation of such systems to low concentrations. Recovery and regeneration of filter aids from the cakes normally is not practiced except in a few very large installations where it might become economical. 

Use of ultrafiltration (UF) membranes is becoming increasingly popular for clarification of apple juice. AH particulate matter and cloud is removed, but enzymes pass through the membrane as part of the clarified juice. Thus pasteurization before UF treatment to inactivate enzymes prevents haze formation from enzymatic activity. Retention of flavor volatiles is lower than that using a rack-and-frame press, but higher than that using rotary vacuum precoat-filtration (21). 

Filtration. Any type of clarification is foUowed by filtration through leaf-type vertical or horizontal pressure filters. Carbonatated Hquors, containing calcium carbonate, may require addition of diatomaceous earth as a filter precoat. Phosphatated Hquors are generally filtered with the addition of diatomaceous earth as precoat and body feed. 

Juice Purification Chemistry. Lime in juice purification serves as a source of calcium, a source of alkalinity, and a source of calcium carbonate which serves as the clarification—filtration medium. 

In most water clarification or softening processes in which coagulation and precipitation occur, at least a portion of the clarified water is filtered. Clarifier effluents of 2—10 NTU may be improved to 0.1—1.0 NTU by conventional sand filtration. Filtration ensures acceptable suspended sohds concentrations in the finished water even when upsets occur in the clarification processes. 

Most surface waters contain varying amounts of suspended solids, including silt, clay, bacteria, and vimses and it is necessary to remove these before to distribution to the domestic or industrial consumer. Suspended soHds not only affect the acceptabiUty of the water but also interfere with disinfection. The principal treatment processes are sedimentation (qv) and filtration (qv). Sedimentation alone is rarely adequate for the clarification of turbid waters and is of htde or no value for the removal of such very fine particles as clay, bacteria, etc. Table 1 shows the effect of particle size on the sedimentation rate of a soHd having a specific gravity of 2.65 in water at 20°C. 

By objective. The process goal of filtration may be diy solids (the cake is the product or value), clarified liquid (the filtrate is the product of value), or both. Good sohds recovery is best obtained by cake filtration, while clarification of the liquid is accomplished by either depth or cake filtration. 

---