This post would be quite long since agitation scale-up involved trials and evaluation of the parameters. This post is based on Handbook of Chemical Engineering Calculations Fourth Edition by Nicholas P. Chopey.
To understand better about how to scale-up nongeometric liquid agitator, I will use an example. We will make one change at a time to understand its effect.
The example is below:
A process involving water-like liquid must be scaled up from an agitated 18-in diameter, 15-gallon pilot-scale reactor to a 120-in diameter, 7000-gal large scale reactor.
The pilot scale has a 18-in straight side and the large-scale reactor will have a 168-in straight side. Both reactors have ASME dished heads on the top and bottom.
Successful process performance was obtained in the pilot scale with two 6.0-in diameter pitched-blade turbines operating at 350 rpm. It is proposed that the large-scale reactor use hydrofoil impellers instead of pitched-blade turbines, for improved liquid motion.
Each pitched-blade turbine has a turbulent power number of 1.37 and each hydrofoil has a power number of 0.3.
Past scale-up experiences with similar processes, but with geometrically similar tanks, were successful when impeller tip speed was held constant. Read More