Table 7 Equations used for determination of the EDCF and description of terms with respective units

\(k=\left(\frac{\pi }{4}\right)\left(\frac{W}{D}\right)\)

k: impeller geometrical factor

W: impeller blade height (m)

D: impeller diameter (m)

P: power input (W)

P₀: ungassed power number of the impeller

ρ: broth density (kg m⁻³)

1/t_c: circulation frequency (s⁻¹)

Fl: impeller flow number

N: stirring speed (s⁻¹)

V_L: working volume (m³)

\(P= {P}_{o }\rho {N}^{3}{D}^{5}\)

\(\frac{1}{{t}_{c}}=\frac{(FlN{D}^{3})}{{v}_{l}}\)

\(EDCF= \left(\frac{P}{k{D}_{3}}\right) \left(\frac{1}{{t}_{c}}\right)\)