Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface

Marcos Rodriguez (1) , Florent Ravelet (2, 3) , Rene Delfos (3) , Geert-Jan Witkamp (1)

1 Laboratory for Process Equipment
2 LEMFI - Laboratoire d'énergétique et de mécanique des fluides interne
3 AHD - Laboratory for Aero and Hydrodynamics

In a cylindrical scraped heat exchanger crystallizer geometry the flow field influence on the local heat transfer distribution on an evenly cooled scraped heat exchanger surface has been studied by direct measurements of the heat exchanger surface temperature and the fluid velocity field inside the crystallizer. Liquid Crystal Thermometry revealed that the local heat transfer is higher in the middle area of the scraped surface. Stereoscopic PIV measurements demonstrated that the secondary flow inside the crystallizer is responsible for this phenomenon. These local heat transfer inhomogeneities on the heat exchanger surface reduce the control over the onset of the formation of an isolating scale layer, and therefore limits the production capacity of the crystallization process.

Mots clés: Heat transfer; Heat exchanger; Scraped heat exchanger crystallizers; Cooling crystallization; Scale formation; Flow field measurements; PIV; LCT

Domaines: Dynamique des Fluides [physics.flu-dyn]

Marcos Rodriguez, Florent Ravelet, Rene Delfos, Geert-Jan Witkamp. Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface. 2008. ⟨hal-00376150⟩