Waste heat utilization in a ceramic industry

The scope for energy conservation in a ceramic factory was studied. It was found that the sensible heat of the flue gas from kilns could be used to heat the casting shop. A pebble bed waste heat regenerator was chosen to collect the sensible heat of the flue gas. Experiments were performed on a pilot plant scale pebble bed to study its characteristics using a flue gas stream whose temperature and composition were similar to the factory conditions. The results of the heating cycle showed that 14 500 kcal h⁻¹ of heat can be collected from flue gas in a 0·126 m³ bed. This information was used to design a complete retrofit system. Financial analysis of the proposed project showed that it has a pay-back period of 15 months. © 1997 by John Wiley & Sons, Ltd.