Cyclone separators theoretical particle size

A cyclone separator 0.3 m in diameter and 1.2 m long, has a circular inlet 75 mm in diameter and an outlet of the same size. If the gas enters at a velocity of 1.5 m/s, at what particle size will the theoretical cut occur ... 

The efficiency of the cyclone separator is greater for large than for small particles, and it increases with the throughput until the point is reached where excessive turbulence is created. Figure 1.55 shows the efficiency of collection plotted against particle size for an experimental separator for which the theoretical cut occurs at about 10 ttm. It may be noted that an appreciable quantity of fine material is collected, largely as a result of agglomeration, and that some of the coarse material is lost with the result that a sharp cut is not obtained. 

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