Previous works devoted to the development of the swirl flow generated by ro
tation of the marine screw impeller in the loop toroidal reactor show that
the flow structure is characterized by the existence of a secondary flow. T
he deformation of the axial velocity profile, due to the bends curvature an
d the rotation of the agitator, modify considerably the friction and the tr
ansfer near the wall. The objective of this work is to study the toroidal f
low and to characterize the wall turbulence. The wall shear stress distribu
tion in the torus were performed by using an electrochemical method. The me
asurements of the wall shear stress were carried out in the inner and outer
walls. The evolution of the wall velocity gradient with the longitudinal d
istance depends on the location in the torus. These results allow to obtain
information about the friction factor, which is compared with the one meas
ured directly by using piezometric connections. The experimental determinat
ion of the axial dispersion coefficient is obtained by using the dispersion
plug flow model with a total recirculation. Finally, a relationship betwee
n the turbulent characteristics and the mixing parameters has been establis
hed.