1)       The film coefficient in a vessel with a jacket that has no agitating nozzles is addressed as flow through an annulus.  Agitating nozzles on the jacket provide much superior heat transfer and are recommended for full jackets.  Frequently external coils or limpet jackets can be used as well and can be less expensive depending on the pressure rating requirements of the vessel and/or jacket.

2)      The inside film coefficient is best calculated with a correlation from J.R. Bourne, which relates power dissipation to heat transfer.

3)      The wall resistance in an agitated vessel can be significant, especially in glass-lined vessels.

4)      There is a good treatment of agitated vessel heat transfer in “Process Heat Transfer” by Hewitt, Shires & Bott, which should be available in most technical libraries.