A new multilayer baffle for intensifying the catalyst regeneration process of a dense bed fluid catalytic cracking (FCC) regenerator was proposed and its effects on hydrodynamics and gas/solids mixing in fluidized beds of FCC particles were investigated experimentally in a large cold fluidized bed model. Experimental results show that, due to scale-up effects and serious gas bypassing, the new baffle was more effective in improving gas-solids contact as indicated by the weaker pressure fluctuations, increased bed expansion, and reduced freeboard particle carryover measured in the baffled fluidized bed (BFB) of this study. Compared with baffle-free fluidized bed (FFB), the new baffle can reduce internal gas circulation flux by 89-96%, indicating stronger suppression on gas/solids backmixing. An established baffled FCC regenerator model shows that, in a regenerator with this new baffle, cleaner regenerated catalysts can be obtained with less air consumption and catalyst inventory. Moreover, the modeled results also indicate that the lower part of the dense bed should be the best baffle mount level.