Abstract
Several papers have emphasized that the flow characteristics in the ion exchange compartment with spacers show much influence on the performance of the electrodialytic equipment. Pnueli et al. obtained an equation on the velocity distribution between parallel plates separated with a spacer, applying the Brickman's equation. However, any attempt has not been carried out to investigate the permeability which is the most important among parameters in the equation.
In the present work, the values of the permeability were experimentally determined by the measurement of pressure drop in the ion exchange compartment. The results show that the permeability is not affected by the dimensions of the compartment, the viscosity and the flow velocity of the fluid, but depends on the diameter of fibers, the thickness and the void fraction of the space. An experimental equation which relates the permeability to the properties of spacers is presented. Further, by the use of the dimensionless parameter on the equation of the veiocity distribution, the degree of the fluid mixing in the presence of the spacer is determined. From the values of permeability and the parameter, it has become apparent that the spacer of the honey-comb textile which has larger void fraction in the best of all the spacers used in the pres ntexperiment.
