The experiments of residence time distribution in SK static mixer were done by using the pulse tracer method. The effect of different factors on residence time distribution was evaluated based on mixed orthogonal experiments. The results of range analysis showed that the factors impacting the mean residence time were velocity, diameter, cross section, and arrange mode of elements in turn; but for variance the factors were diameter, cross section, velocity, and arrange mode of elements in turn. From the comparison of residence time distribution curves, the flow in the static mixer tended to be plug flow along the axial direction at the same velocity and diameter. The quantization analysis, the effect of factors on the mean residence time, was done by using the power function considering the numbers of mixer element, diameter and velocity, and so on. The validity of this function was testified by the experiment results of Di=40 mm and the mean error was 12%. The variance value was larger at lower flow rate due to the “wall flow”. The results of the variance analysis agreed with the previous analysis of residence time distribution curves. 

The velocity distribution of the tube in the kenics static mixer was simulated by using the CFD software．And flow field of partial type static mixer was measured by using LDV （Laser Doppler Velocity）． The discussions were given to the
effect of length －to－diameter ratio of mixing elements on the velocity distribution and turbulent property in kenics static mixer．The results show that the trend of the velocity of different direction and turbulent kinetic energy along axis is changeless with the variety of the length －to－diameter ratio of mixing elements ．But the value of amplitude is influenced．When the length－to－diameter ratio of mixing elements is little，the value of amplitude of velocity of different direction and the slope is bigger．The effect of the radial velocity is obvious and that of axial velocity is minor．With the length－to－diameter ratio of mixing elements diminution，the turbulence degree and turbulent kinetic energy enhanced and the increasing of the velocity is greater than the variation of velocity.

The time series of instantaneous velocity in the Kenics static mixer, 0.04 m in diameter and 1.25 in aspect ratio, were conducted with laser Doppler particle analyzer. The signal of velocity fluctuation were decomposed into signals of different frequency band including 0~12.5, 12.5~25.0, 25.0~37.5, 37.5~50.0, 50.0~62.5, 62.5~75 Hz and more than 75 Hz based on Fourier transform. The linear and nonlinear correlation characteristics of signal of different frequency band were evaluated with auto-correlation function and mutual information function, respectively. The experimental results indicate that the signals of more than 62.5 Hz in frequency have no linear correlation, and there are no nonlinear and linear correlation for the time series signal which is over 75 Hz in frequency.

The turbulent flow characteristic in a stirred mixer with propeller was predicted based on multi-reference frame by using CFD turbulent model. Some detailed information about the velocity and turbulence kinetic energy was obtained. The simulated results show that the mean velocities increase firstly then decrease as radial position increasing, while the values of mean velocities close to the impeller are larger which were found in good agreement with the experimental results reported in the literature. Though the velocity distributions at different axial position above the stirrer are also much smoother, the values of velocity increase firstly then decrease in the discharged zone. The turbulence in the discharged zone tends to be nonuniform and the magnitude of the turbulent kinetic may have 7~9 times difference at the same axial or radial position. It is priority to select propeller for the axial speed field as main field, long distance transmission compared with traditional typical three-blade impeller of 45°.

The characteristic of flow resistance in the new type static mixers was investigated based on the microscope flow character by using the computational fluid dynamics(CFD) software. It can be seen from the velocity vectors of axial cross-sections that there was the spin flow, reverse to the revolving direction of the mixer element groups in the new type static mixers. The relationship among all factors influencing flow resistance in the static mixers was simplified by using the dimensional analysis and π theorem. A general relationship of friction coefficient of the flow resistance was gained by data reduction and regression. It offers the theoretical base for the industry application.