**6. Model results**

Further studies were made to understand the behavior of some parameters used in the mathematical modeling using Rietema's correlations. The influence of particle dimensions was studied to see the impact on the cyclone diameter (D). **Figure 7** shows this relationship, and it can be deduced that the curve is close to exponential. This means that for particles smaller than 1 μm, the dimensions of the cyclone would be too small to be effective. If the minimum particle size is above 10 μm cyclone dimensions become exponentially bigger, which result in extremely big diameter (D) values. The problem is that Rietema's model used to produce the dimensions is not consistent for larger particle dimensions.

The second study related the % of solids inside the fluid, with the cyclone diameter (D) (**Figure 8**). The relation is linear for values of % solids between 1% and 21% and the change in diameter decreases as the particles increase.

The third study compered the solids density inside the fluid (Graph 3). The result, shown in **Figure 9**, conclude that for densities less then 1100 kg/m<sup>3</sup> , the

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**Figure 7.** *Hydro cyclone Rietema model, solids dimensions study.*

**Figure 8.** *Hydro cyclone Rietema model, %solids study.*

dimension of the diameter (D) become unreliable. For bigger densities the diameter slightly decreases but the variation will become close to none. It can be seen that already from densities of 1200 kg/m<sup>3</sup> the model starts to get defective.
