Abstract The influences of orifice velocity, perforated rate and particles on jet penetration length and dead zone height were investigated in the grid zone of a two-dimensional fluidized bed by photographs and visual analysis. The results showed that with the increase of the orifice velocity and diameter of orifice, the jet penetration length and particle moving zone increased, while the dead zone height decreased. At the same orifice velocity, the more holes the distributor had, the higher the jet penetration length was. And at same U/Umf(U was the superficial gas velocity and Umf was the minimum fluidization velocity), the jet penetration length of different particles were almost the same. The correlations in different literatures were compared and a new correlation of jet penetration length was proposed by including a dimensionless group U/Umf. A correlation of dead zone height was obtained by fitting the data derived under different operating conditions.
