A Worked Example, Separation Performance

A Worked Example for the Prediction of Cyclone Separation Performance 

Let us predict the separation efficiency of the cyclone reported in Ap -pendix 4. A. As for the pressure drop, we have different models at our disposal and this is advantageous in that we are not dependent upon just one model for our predictions. If, for the case of X50, various model predictions were to differ by, say, 50%, we would want to allow for this variation and interpret the results accordingly—not becoming overly attached to any one model s predictions. 

In order to predict separation performance we require information about the solids feeding the cyclone, in addition to the geometrical data given in Fig. 4.A.1, information about the solids feeding the cyclone. Let us say we are feeding the cyclone a cement powder of density 2730 kg/m , at a relatively light load of 2.5 g per kg of gas. The feed has a volume (or mass) mean size of 27.5 yum and follows a log-normal volume or mass size distribution for which (Inx) = 3.32 and a (the spread) = 1.2. F x) is then given by Eq. (2.B.5) shown in Fig. 5.A.I. 

The cyclone to which we are feeding the solids is quite large. We would therefore expect it to have a relatively large cut size. 

Finally, we need the inlet velocity, which we take as 30 m/s, like in the previous chapter. 

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