Current distribution diaphragm cell

A comparable cell design - but with flat, solid, or perforated electrodes, mounted parallel nearby the diaphragm - avoids the above-mentioned problems and can work with optimal current distribution [84]. 

Each electrolytic application demands a unique approach to anode structure design and fabrication. Factors such as current distribution, gas release, ability to maintain structural tolerances, electrical resistance, and the practicality of recoaiing must be taken into account. The most commercially accepted design for diaphragm chlorine cells is that of the expandable anode (Fig. I). 

The cylindrical cell is a more convenient cell because the potential or current distribution is nearly perfect. It can be used undivided or divided with a cylindrical diaphragm. This cell type is used with a sacrificial electrode cell, generally with the undivided configuration. 

FIGURE 10.3.15. Current distribution on the upper surface of the cathode in a diaphragm cell. Reduced current density is defined as the ratio of the local current density, /, to the average current density, ir. 

Cathode Corrosion. One of the problems encountered with MDC-29 diaphragm cells is the severe cathode corrosion at the cefi liquor/hydrogen interface near the cathode screen, which prevents deposition of good diaphragms. The primary current distribution profiles were calculated [15] using the finite difference method and the results... 

The use of diaphragms in commercial cells has already been mentioned. The ideal diaphragm should have the following properties it should be permeable to ions but not to molecules it should not add much to the cell resistance and at the same time should provide a complete barrier to the passage of gas bubbles and to diffusion it should be homogeneous to provide even current density distribution it should be chemically resistant to conditions in the cell should have some mechanical strength and should be cheap. All these requirements clearly cannot be met in one diaphragm material and a compromise must usually be made. 

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