HEAT TRANSFER

Heat transfer (as mixing application) is defined as the transfer of heat between the contents of the vessel and a heating or cooling surface provided for that purpose. The surface may consist of coils, plates, the wall of the vessel, etc. A heat transfer coefficient can predicted for most systems of interest. This coefficient is called the “inside” heat transfer coefficient. It is a measure of the heat flow capacity at the surface in direct contact with the vessel contents. The coefficient of the wall of the surface and from the heating/cooling medium to the outside wall of the surface must be determined separately, and combined with the inside coefficient to determine an “overall” coefficient.

Vessel Design Considerations

See Liquid Blending. Liquid blending and heat transfer have much in common. The difference is that a heat source (or sink) is installed in the vessel. These may be pipe coils, plates or the vessel may be jacketed. There are a great variety of coil arrangements used for heat transfer. Some coil assemblies can serve as baffles, but when they cannot, baffles must be installed in the vessel when required. Jacketed vessels are almost always round and usually used when scraped wall agitation is expected. However a jacketed vessel can also be used in most other circumstances.