The variation of solids speed in the active layer might give a good contribution to the agitation of the solid–liquid mixture in the can, therefore enhancing convective heat transfer. However, when the solids fraction increased to 40% (w/w), the solids speed was very KU-60019 ic50 close to that of solid body (Figs. 4 and 5C). Solids nearly followed a concentric flow and moved, more or less, as a rigid body, and acted as scraper to the surface reducing the boundary layer at the inner wall and enhancing heat transfer in the low viscosity liquid. When the water

was replaced by the golden syrup, the solids suspended in the golden syrup or stayed by the can wall due to the increased density and viscosity of the liquid. Z-VAD-FMK mw Solids were dragged upwards by the rotating can, fell down when they reached the headspace, the solids speed was relatively uniform (Fig. 6) and very similar

to the speed of the can body (Fig. 4). It means that the solids for any fraction moved, more or less, as a nearly rigid body within the entire can, giving little contribution to the convective heat transfer from the wall to the centre. In the diluted golden syrup, the solid flow pattern was different. The solids floated over the central region of the can. On the right side of the can, solids tended to move straight upwards, rather than (i) reposed on the wall of the can as observed in water or (ii) suspended in the golden syrup as observed in the undiluted golden syrup. On the left side of the can, solids tended to move

close to the can wall. The upward speed was higher than the speed of solid body, particularly in the central region. The downward speed was less than the speed of solid body (Figs. 4 and 7). The speed distribution from the side view of YOZ plane was non-uniform. This non-uniform motion of the solids in the can will agitate the mixture and this might enhance the convective heat transfer. Through comparing the solids motion in the diluted and undiluted golden syrup, it can be seen that a slight dilution of the golden syrup might significantly change the solids motion, therefore the heat and mass transfer in the can. Fig. 8, Fig. 9 and Fig. 10 present internal spin rate of solids over a 20-min period from the side view of YOZ plane. Fig. 11 shows the range of internal spin rate of solids over a 20 min period. Table 1 shows internal spin Metalloexopeptidase rate of solids in the three liquids, calculated from Eqs. (17) and (18). It is very interesting to note that the solids spin is related to the translational motion, and is dependent on the solids fraction, the liquid viscosity and the solids position within the rotating can. When the can was rotated in an anticlockwise direction, solids in water reposed on the right-side wall, and rotated upwards. The right-side wall applied a drag force to the solids near the can wall. The passive layer was located adjacent to the right-side wall, where solids moved almost as a packed rigid body.