Effect of Carbon Cooling on High-Current Arcs

The influence of carbon cooling, especially of the positive carbon, on the properties and the mechanism of the high-current carbon arc are studied systematically. An experimental super high-intensity carbon, designed by the National Carbon Company especially for this service, was used. With respect to the technical advantages of carbon cooling (increased arc steadiness, reduced positive-carbon consumption, reduced crater depth, higher possible brightness) our results agree with those presented simultaneously by the National Carbon group. Quantitative relations between current, net arc voltage, net arc wattage, gross arc wattage, crater brightness, carbon consumption, light efficiency, and crater depth for the cooled and the uncooled arc are presented in the form of graphs based on more than 1000 measurements. The considerable reduction of the net arc voltage by cooling the positive carbon indicates an influence of carbon cooling on the arc mechanism itself which is explained, on the basis of the author's anode drop theory, as a consequence of chemical and structural changes in the carbons resulting from the difference in temperatures near the burning end. These changes have been confirmed by X-ray diffraction studies.

Print ISSN

0097-5834

Published

1949-04

Content type

Original Research

DOI

10.5594/J12507