I’m concerned about the state of traditional ceramic manufacturing here in the U.S. Our service society would not—and could not—exist without the creation of wealth that only happens when a product is made from raw materials.
Understanding what happens to the fuel that you pay for when you fire your kilns will enable you to make informed decisions when you are asked—or told—to reduce the energy consumption of your firing systems.
Several traditional energy programs exist, including alternative fuel systems, conservation of fuel through kiln adjustment, and retrofit modifications that improve operating efficiency. This month's column covers alternative fuel sources.
Volatile constituents can sometimes condense in the early preheat or early cooling in certain tunnel kilns. At times, the condensates fall on the product and cause dirt defects. Sometimes the condensates are so chemically reactive that it damages the kiln lining by fluxing the refractories in both the preheat and cooling zones. In either case, undesirable precipitation of volatiles can cause serious product loss or even kiln damage.
Tunnel kilns account for the bulk of worldwide ceramic firing. For many products, a tunnel kiln offers the potential for better temperature uniformity and product quality—with an energy consumption that is typically half that of periodic firing systems.