Carbon brushes for steel-mill equipment

The problems associated with brush application on commutaling-type equipment in the iron and steel industry are discussed in relation to type of equipment and conditions encountered in service. The paper also discusses a newly defined measure of brush performance, termed “commutation factor,” which provides an improved basis for control of the performance characteristics of brushes. Mention is made of the development of electrographitic grades having mild polishing action, designed to prevent the formation of troublesome surface film on commutators exposed to the contaminating atmospheric conditions frequently encountered in steel mill applications.