Thank you for the answers, Stonecold and Olynyk.
The cooling will be done in stages. For some of the stages the temperature difference between emulsion and cooling water will be bigger for others smaller.
I will experiment the constast flow rate of the cooling water and the automated one.
Also...
An emulsion of a known composition has to be cooled from 80C to 50C, at a constant rate, in an interval of 100 minutes with water. The cooling water temperature can be setted at different temperatures (i.e.10DGC lower than emulsion in the vessel). How can I calculate the flow rate of the cooling...