Eco-friendly self-cooling system of porous onggi ceramic plate by evaporation of absorbed water

Abstract

Porous ceramic plates were prepared from Onggi clay and bamboo charcoal powder at 1100 and 1200oC and their porous properties and water absorption, and the cooling effect of porous plates, were investigated to produce eco-friendly porous ceramics for a self-cooling system that relies on the evaporation of absorbed water. Porous properties were dependent on the particle size of charcoal powder pore forming additive and the firing temperature; properties were also found to be dependent on the total pore volume, average pore size and porosity, which had values of 0.103 - 0.243 cm3/g, 0.81 - 2.56 mm and 20.9 - 38.2%, respectively, at 1100oC and 0.04 - 0.18 cm3/g, 0.33 - 2.03 mm and 10.8 - 30.9%, respectively, at 1200oC. Cooling temperature difference of flowing air parallel to surface of porous ceramic plates fired with two kinds of charcoal powder at 1100oC was 3.5 - 3.6oC at 26oC and 60% of relative humidity in a closed box. Cooling temperature difference was dependent on the number of porous plates and the distance between porous plates. A simple and eco-friendly cooling system using porous ceramic plates fired from Onggi clay and charcoal powder was proposed.