ABSTRACT
B determinant − B* corrected determinant − bi coefficient in Eqn (6.3) as given in the text C coefficient in Eqn (6.22) − ci concentration kg m-3 Dax coefficient of effective axial diffusion m2s−1 d1 internal diameter of the vessel m d2 diameter of the stirrer m d3 diameter of the flow cylinder m dR internal diameter of the section m dsp equivalent slit diameter dsp=[4/π(ALnL+AR)]1/2 m dw diameter of the stirred cylinder m E activation energy J mol−1 e acentric stirred area m h0 working height (non-aerated) m h1 height of stirrer blades m h2 height of stirring unit m KI inhibition constant kg m-3
Symbol Definition Unit Ks Monod constant; substrate concn at which half µmax is
reached kg m−3
m number of factors in the planned expt. − ms maintenance coefficient s−1 N number of experimental points Ns number of the vertical current breaker with the diameter
d3 −
n speed of the stirrer s−1 ni exponential in Eqn (6.20) − nL number of acentric holes in the section − P stirring power kg m2s−3 P number of constants or polynomial degree −
specific mass change velocity s−1 Ri mass change velocity kg m−3s−1 T temperature K tR duration of reaction s v coefficient of reaction − w average flow speed m s−1 Yj/i coefficient of yield with respect to product j and substrate
i kg kg−1
Indices
i reaction component, current number j reaction product, current number L fluid max maximum P, p product S, s substrate X, x biomass
Dimensionless Constants
Bewehrungs number
Bodenstein number
Newton number, power number
Strouhal number
Reynolds number for laminar flow
Reynolds number for turbulent flow
πi General dimensionless number
Greek Characters
Θ temperature °C η dynamic viscosity kg m-1 s-1 µ specific growth rate s−1 v kinematic viscosity m2s−1 ρ density kg m−3
6.2 STATISTICAL PLANNING OF EXPERIMENTS
6.2.1 Basic Principles
In the last 30 years scientific theory has caused a complete change in the planning and execution of experiments. Previously an experiment was regarded as a deterministic procedure. The classic concept is that n−1 factors (where n≥2) were kept constant and that one factor after another was altered to determine the relationship between the result and the variable. Conversely the theory of modern experimentation is based on the following principles.
