A novel diffusion cell was designed to determine the tortuosity factor of porous solid catalyst with steady state method Under the conditions of temperature range of 299～368 K and pressure of 0 1 MPa,Wicke-Kallenbach steady state diffusion experiments are carried out for N 2-CO 2 and Ar-CO 2 bicomponent system with Ni/Al 2O 3 catalyst.

Parameter estimation method is adopted to get the effective diffusion coefficient from experimetal data,thus the tortuosity factor can be obtained.

The tortuosity factor is an important parameter of the catalyst and it has an effect on the global reaction rate of gassolid catalytic reaction, the capacity of the reactor and the efficiency of the catalyst etc.

A gas permeation model associated with the structure of membrane and a method of determined membrane structure parameters such as tortuosity were established.

So far,the clear relationship between tortuosity and the microstructure of porous media is uncertain.

The tortuosity factors of LB energy-saving high temperature shift catalyst are measured under ambient pressure at 40 ℃ and 60 ℃,respectively.

Under atmospheric pressure and at 30-500 C, the obtained tortuosity factor (τ) of the catalyst and carbon fibre are 1.

Effect of stator curve to automobile power steering pump noise;

The quality of stator curve precision grinding is influenced by the movement accuracy of workshop and linear velocity of grinding.

The stator curve of the power steering vane pump plays an important role in reducing noise.