Abstract
A spacer is usually mounted in an ion exchange compartment of an electrodialytic equipment. When a very thin spacer commercially available is used, the thickness of the spacer is thinner than that of the gasket of the ion exchange compartment, and some space arises on both sides of the spacer.
The equations on the distributions of the flow velocity inside and outside the spacer in the above case were derived from the modification of the Brickman's equation.
To study the validity of these equations, the velocity distributions outside the spacer under a variety of spacers and flow rates were measured by the tracer-photographic method. The velocity distributions obtained experimentally were in fair agreement with the theoretical results obtained by the equations. The pressure drop and flow rates in the compartment in the presence of some space on both sides of spacer were also measured experimentally by altering the thickness of the gasket of the ion exchange compartment and the thickness of the spacer. The permeability calculatedby substituting these values in the theoretical equation in the case where some space was present on both sides of spacer was in good agreement with the one obtained when the ion exchangecompartment was filled with spacers. These results proved that the velocity distributionsin the ion exchange compartment were represented by the theoretical equation derived in the presentpaper. Further, the equation for estimating the dimensionless parameter in these velocity distributions was also obtained.
