Liquid-cyclones

FIG. 14-108 ( 7)Liqi lid entrainment from the bottom of a vessel by centrifugal flow. (Rietema and Veroer, Cyclones in Industry, Elsevier, Amsterdam, 1961. ) (h) Gas-oiitlet sldrt for liquid cyclones. (Stern et al. Cyclone Dust Collectors, Ametican Petroleum Institute, New York, 1955. )... 

A low-pressure-drop liquid cyclone is sometimes used to clarify liquor discharged from the evaporator. The driving force is the pressure drop across the circulating pump. Thickened slurry is returned through a wide-open cyclone underflow connection to the circulating piping before the pump suction. 

Liquid Cyclone Design (Based on air-water at atmospheric pressure) Figure 4-49... 

Cyclones can be used for the classification of solids, as well as for liquid-solid, and liquid-liquid separations. The design and application of liquid cyclones (hydrocyclones) is discussed in Section 10.4.4. A typical unit is shown in Figure 10.3. 

Liquid cyclones can be used for the classification of solid particles over a size range from 5 to 100 jim. Commercial units are available in a wide range of materials of... 

Glanded cottonseed has been used to produce a defatted cottonseed flour with reduced gossypol content by a procedure known as the liquid cyclone process (LCP). LCP cottonseed flour has been used in the preparation of many foods that have been tested in several animal and human nutrition studies. The commercial production of LCP cottonseed flour has not been successful (5). 

Figure 12. E ect of succinylation on the foam and protein solubility properties of liquid cyclone processed cottonseed flour in suspensions at various pH values...

These data demonstrate that changes in foam properties of liquid cyclone processed cottonseed flour are inducible by treatment with succinic anhydride. Gel electrophoretic and solubility data show that there are alterations in the physical and chemical properties of proteins, and in certain cases these changes improve foam properties, that is, improve solubility and polypeptide dissociation of proteins at the interface of the foaming solution. Similar results have been reported for succinylated soybean and sunflower seed proteins (44. 46). 

Reentrainment from the bottom of the cyclone can be prevented in several ways. If a typical long-cone dry cyclone is used and liquid is kept continually drained, vortex entrainment is unlikely. However, a vortex breaker baffle in the outlet is desirable, and perhaps a flat disk on top extending to within 2 to 5 cm (0.8 to 2 in) of the walls may be beneficial. Often liquid cyclones are built without cones and have dished bottoms. The modifications described earlier are definitely needed in such situations. Stern, Caplan, and Rush (Cyclone Dust Collectors, American Petroleum Institute, New York, 1955) and Rietema and Verver (in Tengbergen, Cyclones in Industry, Elsevier, Amsterdam, 1961, chap. 7) have discussed liquid-collecting cyclones. 

The next step in the process is removal of remaining soluble and insoluble protein. Starch slurry discharging from the primary centrifugal separator must be diluted with process water to a slurry density of 10-12° Baume (18-21% dry solids). The starch may then be further purified in a second centrifugal separator to a final insoluble protein level of <0.38% dry basis (preferably 0.27-0.32% dry basis). However, since solubles content of the slurry must next be reduced by filtration of centrifugal decantation, the second step currently preferred is to utilize 8 to 14 stages of liquid cyclones which simultaneously remove residual gluten and wash the starch.207-209... 

These equations with the operating parameters give the performance characteristics of a specific hydrocyclone design. A similar series of equations can also be used to describe the performance of gas cyclones of different, geometrically similar design. Gas and liquid cyclones are also often used for size classification in grinding circuits. 

---