The effect of end-over-end rotation on heat transfer rate to canned Newtonian liquids was studied with two cans (length: diameter ( L D) = 0·73 and 1·37) over the range 0-38·6 r.p.m. and radius of rotation 0-14·9 cm. Data were obtained with water, glycerine and 30%, 50%, and 60% sucrose solutions. The agitation induced oscillations of the centre temperature about an increasing average value. The oscillations were more pro-nounced in viscous liquids. The heat transfer coefficient (HTC) was found to be independent of the radius of rotation and L D. Head space volume between 3 and 9% did not affect the HTC. A correlation was developed in terms of Nusselt, rotational Reynolds, and Prandtl numbers to predict the HTC: Nu = 2.9Re0.436Pr0.287 The characteristic dimension in Nu and Re was the radius of rotation. This correlation, with R2 = 92%, is valid for Re: 83 - 2·1 × 105 and Pr: 2·8 - 49. Attempts to improve the correlation by incorporating the Grashof number, L D and head space volume as well as other characteristic dimensions were not successful.
All Science Journal Classification (ASJC) codes
- Food Science