(457d) Experimental and Numerical Heat Transfer Investigation in a Mixing Vessel with Cooling Jacket

Experimental and Numerical Heat
Transfer Investigation in a Mixing Vessel with Cooling Jacket

Thomas Eppinger, Alexander Heyter, Ravindra
Aglave, Stefan Wollny

Although agitated mixing vessels are widely
used in the chemical, pharmaceutical and food industry, their design with
respect to adding or removing heat is still connected to uncertainties and a
subject of research. For example the standard work for engineering heat
transfer problems, VDI heat atlas, lists different correlation for the heat
transfer coefficient, which differ for a given Re-number by a factor of
approximately 3. The reason for this are certain homogeneity assumption which
do not hold.

In this contribution we are investigating
the heat transfer in a heated mixing vessel with a Rushton turbine and a water
cooled cooling jacket. 3D CFD simulations are validated with respect to power
input, heat transfer and residence time distribution in the cooling jacket with
detailed experimental data from the lab. Based on the detailed information from
the CFD simulation the local heat transfer coefficient on the inner as well as
on the outer side wall is analyzed and the non-homogeneities can be quantified.
As a side effect, also the appropriate CFD cell resolution to capture power
input and heat transfer is discussed.

Figure 1: Fully-baffled mixing vessel with cooling
jacket

Figure 2: Heat transfer coefficient as function of impeller
Re-number according to VDI heat atlas