Axial current conduction in polarized slag layers on coal-fired MHD generator walls

A mechanism that produces high-voltage gaps on an MHD (magnetohydrodynamic) generator cathode wall that is otherwise shorted by metallic potassium is quantitatively examined. The results presented relate the amount of axial current required to produce high-voltage gaps along the cathode wall of the generator to the thickness and degree of potassium saturation of the slag layer along the wall. They confirm the viability of the axial current model for opening high-voltage gaps on a coal-slagged channel