Electric Firing of Advanced NSiC Kiln Shelves
Advanced NSiC kiln shelves are already being used in top-loading resistance coil element kilns around the world, where their light weight and lower mass offer several advantages over traditional shelves.
While a 1-in-thick cordierite shelf has been the standard choice for electric kiln firings to cone 6 and above, it also consumes a lot of energy and stacking space. This is especially the case with 7 to 20-cubic-foot top-loading kilns, where space is at a premium.
Not only will an advanced NSiC shelf stay flat in this application, but its 5⁄16-in. thickness also allows for more stacking space and reduced energy costs. It is also easier to lift in and out of top-loading kilns due to its lighter weight. The initial investment for the advanced NSiC shelves is significantly higher than cordierite shelves in electric firing applications; however, it is easy to realize a substantial return on investment when energy and productivity savings are considered.
It should be noted that there has been a long-standing belief in the pottery market that silicon carbide shelves cannot be used in electric kilns due to the risk of electrical shock.
Silicon carbide is an electrical conductor; however, the electrical resistance of advanced NSiC shelves depends on several variables, making the likelihood of an electrical shock minimal. As with any type of powered equipment, observing common sense rules, precautions and maintenance recommendations will eliminate potential hazards. For instance, advanced NSiC shelves should not be used in kilns that are in poor repair with unpinned elements protruding out of their grooves, and an operator should never reach into an electric kiln unless the power is turned off. More detailed information can be obtained from an application specialist.