Part 9: the Ecokiln-environmentally friendly kiln firing

摘要

Industrial scale test runs show that the Ecokiln~R achieves the goal that was aimed at the fluoride emission is well below the limit of 5 mg/m_3 (see figure 4). Furthermore, product quality is very good. Control of the kiln is simple and flexible, deterioration after one year of operation. The pilot Ecokiln~R typically consumes energy at the rate of 3.0 MJ/kg (720 kcal/kg). It is expected that the energy consumption of an industrial Ecokiln~R will be lower than that of a conventional roller kiln. That part of the Ecokiln~R's flue gases emanating from the radiant tube burners are free from fluoride, chloride and sulphur so they can be used in another process without creating environmental problems. It seems likely that the investment costs for an Ecokiln~R will be about 40 percent higher than for an equivalent conventional kiln, due to the costs of the radiant tube burners. However, these extra costs may be justified by the restriction of fluoride emissions below the regulatory limit, savings resulting from the direct use of the radiant tube burner off-gas for the drying process, and the enhanced glaze quality.