Cyclone Types

Fig. 8. Cyclone types commonly used (161) (a) conventional, large diameter, tangential inlet, axial discharge (b) smaller tube, tangential inlet, peripheral concentrated aerosol discharge (c) small tube axial inlet and discharge (d) smaller tube axial inlet, peripheral concentrated aerosol discharge.

Spray dryers may lose dried egg products out of the stack. Cyclone-type coUectors, usually used as the secondary coUector, are not properly designed to coUect products efficiently. A weU-designed cyclone coUector recovers only 85—90% of spray-dried egg white, with 10—15% lost out of the stack, and 94—95% of egg products co-dried with carbohydrates. Bag-type coUectors are needed for 100% recovery of both these products. Plain whole egg and plain egg yolk products are capable of being coUected almost 100% with a cyclone coUector, but a bag coUector is advised (see Airpollution control methods). 

Current designs for venturi scrubbers generally use the vertical downflow of gas through the venturi contactor and incorporate three features (I) a wet-approach or flooded-waU entry sec tion, to avoid dust buildup at a wet-dry pmction (2) an adjustable throat for the venturi (or orifice), to provide for adjustment of the pressure drop and (3) a flooded elbow located below the venturi and ahead of the entrainment separator, to reduce wear by abrasive particles. The venturi throat is sometimes fitted with a refractoiy fining to resist abrasion by dust particles. The entrainment separator is commonly, but not invariably, of the cyclone type. An example of the standard form of venturi scrubber is shown in Fig. 17-48. The wet-approach entiy section has made practical the recirculation of slurries. Various forms of adjustable throats, which may be under manual or automatic control. 

Cyclone Separators Finer feed sohds, from 0.04 to 0.0005 m (1.5 in to 28 mesh), may be treated in dynamic separators of the Dutch State Mines cyclone type (Fig. 19-36). In cyclone separators, the medium and the feed enter the separator together tangentially at the feed inlet (1) the short cyhndiical section (2) carries the central vortex finder (3), which prevents short circuiting within the cyclone. Separation is made in the cone-shaped part of the cyclone (4) by the action of centrifugal and centripetal forces. The heavier portion of the feed leaves the cyclone at the apex opening (5), and the hghter portion leaves at the overflow top orifice (6). 

Cyclone type and size of hydrocyclone Geometrical proportions Scale-up constants Running cost criterion... 

The separators in Figure 2.3 may be either a cyclone type, as typified by the Bradley microsizer or a mechanical air separator. Cyclone separators, the theory of operation and application of which are fully discussed in Chapter 1, may be used. Alternatively, a whizzer type of air separator such as the NEI air separator shown in Figures 1.29 and 1.30 is often included as an integral part of the mill, as shown in the examples of the NEI pendulum mill in Figure 2.21. Oversize particles drop down the inner case and are returned directly to the mill, whilst the fine material is removed as a separate product stream. 

The papers in this section represent the theory and current industry practices in the separation process and in separator design. Because separation is such a basic requirement for the oil and gas industry, a wealth of information has been published concerning the process and the various design techniques used in the manufacture of separation equipment. Some of these techniques are proprietary, however, and the details of the design are not readily available. For instance. British Petroleum has done considerable design and testing of cyclone-type separation equipment in recent years with the objective of miniaturizing the equipment for use on offshore platforms. For further details on this and other proprietary equipment, one must contact the manufacturer or licensee of the equipment. 

Leith, D. and Licht, W. (1972). The Collection Efficiency of Cyclone Type Particle Collectors A New Theoretical Approach. AlChE. Symp. Ser., 68(126), 196. 

Dried material from both harvests in 1999 was separated into leaf and stem samples. Stems were ground through a 1-mm screen in a cyclone-type... 

The cyclone-type of germ recovery equipment occupies less floor space, is easier to maintain and clean, and allows greater response to changes in operating conditions than do the earlier germ flotation methods.5 As shown in Figure 9.6, recovered germ... 

Magnetic heterogeneity of FC-4 was studied by magnetic separation both in gas and in liquid. Gas phase separation was done in a small cyclone-type separator, where the agglomerates were destroyed by the turbulent flow. More than 97 % of the powder was... 

Fig. 3.2 Schematic diagram of a four-stage cyclone-type suspension preheater. P indicates the position at which a precalciner burner may be incorporated.

The production of acetylene from natural gas has been studied in a 60 Hz electrical discharge at atmospheric pressure38. The apparatus consisted of a cyclone-type reactor in which the products could be removed through a hollow electrode. 

HPLC pumps are suitable for that purpose. The column effluent and the reagent should be mixed completely and quickly. In the simplest cases, either a T or Y union can be used. The cyclon type reduces the total volume variance. Table 4.1 displays some derivatizing reagents for the fluorescence labeling of functional groups. 

The deionized sol is filtered to remove traces of resin, and is spray-dried in a spray drier using two-fluid atomization. This type of drier is described in The Chemical Engineer s Handbook, 3rd Edition, by John H. Perry, McGraw-Hill, New York, 1950 p. 840. The inlet temperature is 300°C and the outlet temperature is 110°C. The dried powder is separated from the air stream in a cyclone-type separator and dust bag filter. The powder is stored out of contact with moisture. 

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