3. Extrapolation

3.1 Principle of extrapolation

The aim of scaling-up is to enable results obtained on a pilot or laboratory scale to be reproduced on an industrial scale. In other words, it's a matter of dimensioning a larger-scale agitation system.

Extrapolation is based on the principle of similarity, whereby the ratios of one or more parameters are kept constant at both scales. Five similarities can be considered:

• geometric similarity: the ratios of geometric dimensions are similar at both scales (example: d/t);

• dynamic similarity: power relationships are identical on both scales (example: Re, Fr...);

• kinematic similarity: speed ratios at homologous points are...