Abstract: Among all techniques for parameter estimation, the leastsquares analysis in the time domain is the most reliable, but the computational labor is often considered to be prohibitive. In this paper the authors have employed the FFT algorithm for the computation of the convolution integral, thus greatly shortening the computer time for parameter estimation. Liquid backmixing was investigated in a 92 mm I. D. threephase fluid-ized bed with the following conditions: gas velocity Ug 0.9-5.5cm/s, liquid velocity Ul 0.2 - 8.3cm/s. liquid kinematic viscosity r 0.81 - 39.6mm2/s, liquid surface tension a 39.7- 72.0mN/m and particle size 1.0- 1.25mm. Experimental results were correlated as follows: where Pe is the Peclet number. The mean deviation of the correlation is 15%.

摘要： 时间域最小二乘法分析在所有参数估计技术中是最可靠的,但计算工作量代价很高.本文在参数估计中采用3FFT算法进行卷积积分的计算,从而大大缩短了参数估计的计算时间.在三相流化床内,研究了气、液流速,液体的粘度和表面张力对液相返混的影响,得出了相应的关联式.