An alternative measurement of gas cross flow coefficient between the bubble phase and emulsion phase, and the density of the solid particles in the bubble of a gas-solid, two dimensional fluidized bed are proposed, using the tracer technique and leak-current method.
In the range of u_o/u_mf from 1.5 to 7.0, the gas cross flow coefficient （K_bd）_b and density ratio γb are decreased rapidly and exponentially, respectively, with the increase of u_o/u_mf. It was found that there was a linearlity between (K_bd)_b and u_mf(d_b)^-1/2 and that this proposed (K_bd)_b was one of the catalytic fluidized bed design factor for the gas catalytic reaction.