The present paper aims at rigorously answering these two latter
questions, starting from the theoretical background underlying
the dimensional analysis and extending it to the cases of variable
material properties. More accurately, the objective is to show how
to proceed: (i) to construct a complete list of relevant parameters
able to consider variable rheological parameters, and consequently
(ii) to elaborate, without pitfalls, a set of dimensionless numbers
characterizing all the factors governing absorption rate coefficients
(kla) in an aerated stirred tank where purely viscous fluids with
or without shear-thinning properties are involved. To support this
theoretical approach, a set of experiments was carried out to measure
kla in a stirred tank aerated in volume. Different operating
conditions (rotational impeller speed, gas flow rate) were covered
as well as various fluids (seven purely viscous fluids of which four
have shear-thinning properties).