We report flow visualisation results in a modified Pulsed Baffled Reactor (PBR) where fluid oscillation is achieved by oscillating orifice baffles in contrast to the conventional bellows or piston driven arrangement. A comprehensive set of experiments has been carried out and the effects of orifice diameter, baffle spacing and oscillation amplitude and frequency on the flow patterns have been established in both the modified PBR and a Multi Disc Vibratory Column. The results indicate that the modified PBR can produce highly efficient eddy mixing patterns for a range of operating conditions examined and has the added advantage of eliminating many of the scale-up problems encountered with the conventional PBRs. Combined with the minimal internal surface area of the modified PBR it would allow application of this type of configuration to industrial-scale processes such as suspension polymerisation to be feasible.