Spray centrifugal

A number of techniques have been evolved to disperse liquids in gases in the form of fine droplets. The various atomizing techniques are jet injections, fan sprays, centrifugal nozzles, twin fluid atomizers, impinging jets, and rotary... 

The use of microemulsion spray/centrifuge techniques can reduce the discharges of permethrin to as low as 1.7 g of permethrin discharged per ton of wool treated for the microemulsion spray/centrifuge technique, compared to 8.0 g of permethrin discharged per ton of wool treated for the conventional hank treatments in dyebaths [49-51]. 

Atomiser. A device to produce a fine spray of small particles or liquid droplets. In a spray dryer, the atomiser may be a nozzle, or a spinning head which produces the spray centrifugally. 

Formation of the atomized spray requires application of a force. The commercially available systems employ one of the following in order to create an atomized spray centrifugal energy, pressure energy, kinetic energy or sonic energy, and vibrations. 

Fig. 20. Spray droplet target efficiency in a centrifugal spray tower with a centrifugal field of 100 g (140,281).

The reaction mixture can either be crystallised, centrifuged, and dried, or spray-dried and cyclone-separated to produce a fine crystalline powder having a particle size of 50 p.m. Metal analysis of the AP produced by this method is reported to be less than 0.02 p.g/g. 

The most widely available yeast biomass is a by-product of the brewing industry, where the multiplication of yeast during brewing results in a surplus of ceUs. Eor every barrel (117 L) of beer brewed, 0.2—0.3 kg of yeast soHds may be recovered. In the U.S., a substantial fraction is recovered and made available about 40 x 10 kg of brewers yeast aimually. The yeast is recovered from beer by centrifuging and dried on roUer dmms or spray dryers and sold as animal feed or a pet-food supplement. It can be debittered by alkaline extraction to remove the bitter hop residues, and is then sold mainly by the health-food industry. It is available as tablets, powder, or flakes and is often fortified with additional vitamins. Distillers yeast caimot be readily separated from the fermented mash and the mixture is sold as an animal feed supplement. 

Following carbonation, the product can be further purified by screening. This screening, also used to control the maximum size of the product, is followed by dewatering (qv). Rotary vacuum filters, pressure filters, or centrifuges are used in the mechanical removal of water. Final drying is accompHshed as with natural calcium carbonate in either a rotary, spray, or flash dryer. Products having mean particle sizes from submicrometers (- O-OS fiTo) to several micrometers are available. 

The thermocycle system can be operated only when condensing water is available at a temperature lower than the required chilled-water-supply temperature. Modifications for a centrifugal refrigeration unit include the installation of a small liqmd-refrigerant pump, cooler spray header nozzles, and a vapor bypass line between the cooler and the condenser. Without the compressor operating, a thermocycle capacity up to 35 percent of the refrigeration-unit rating can be produced. 

Spray dryers. Dryer feed must be copoble of otomization by either o centrifugal dish or o nozzle... 

TABLE 12-36 Some Materials That Have Been Successfully Spray-Dried in a 6-m-Diameter by 6-m-High Chamber with a Centrifugal-Disk Atomizer ... 

All venturi scrubbers must be followed by an entrainment collector for the liquid spray. These collectors are usually centrifugal and will have an additional pressure drop of several centimeters of water, which must be added to that of the venturi itself. 

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