본 연구에서는 고-액유동층에 원통형금망을 충전시켜 유동층의 높이에 따른 고체입자들의 축방향 혼합을 분산모델로 해석하였다. 연구결과 빠른 액체의 유속에 대해 다음과 관계가 있었다.
D（㎠/sec）α(U/U_mf-1)^1.6 for U/U_mf>3
또한 실험결과는 본 연구에서 제안된 random walk model과 실험전범위내에서 잘 맞았으며 다음식이 성립하였다.
（u/u_mf 2.45∼9.83, d_s=0.046∼0.077㎝）
D（㎠/sec） = 35.7(U²-U_mf²)^1/2 d_s/(1-ε)

In this investigation, the longitudinal particle mixing in a liquid-solid fluidized bed packed with screen cylinders was studied by employing a colorimetric concentration tracer impulse method. In batch systems, the results showed that the dispersion model was in good agreement with the present experiments and the longitudinal dispersion coefficient was related with the liquid velocity at the higher liquid velocities as following for the screen packed fluidized bed:
D（㎠/sec）α(U/U_mf-1)^1.6 for U/U_mf>3
A random walk model was also proposed and gave an excellent agreement with the experimental results for all the range of present experiments （u/u_mf 2.45∼9.83, d_s=0.046∼0.077㎝） as follows:
D（㎠/sec） = 35.7(U²-U_mf²)^1/2 d_s/(1-ε)