Читать книгу Agitator Design for Gas-Liquid Fermenters and Bioreactors - Gregory T. Benz - Страница 77

We will use equation 4.3. A fermenter with a working volume of 159 m³ and a tank diameter of 4.11 m has an actual airflow of 0.31 m³/s, giving us a superficial gas velocity of 3.01E‐2 m/s. The fluid density is 1050 kg/m³, and the agitator gassed power draw is 158 kW or 158 000 W. Substituting into Eq. (4.3), we get: H = 1.56*(158 000/1050*158)^0.33 * (3.01e‐2)^0.67 = 0.147.

Now, using equation 4.2, we can estimate the gassed volume. Re‐arranging equation 4.2, we can get:

(4.5)

Substituting H: (1‐0.147)V_g = 0.147*159 m³ or V_g = 27.4 m³. The total gassed volume, V_g + V_l, is therefore 186.4 m³, an increase of 17% over the ungassed volume, or a ratio of 1.17 times the ungassed volume. This may also be simply calculated by saying:

(4.6)