TONG Jianhui, FENG Qing
(Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract: For the numerical simulation study on the influence of air-splat cooling velocity on gas-flow in the splat cooling zone of roller hearth kiln, the 3D physical model was constructed and meshed with tetrahedral grid by using CFD Fluent software. The standard K- twoequation turbulent flow model was selected and the boundary conditions were set. The results show that increasing air-splat cooling velocity contributes to reduced difference of the velocity of air-splat cooling in tube as well as of air spraying from tiny holes along the length of tubes,which makes the temperature distribution of air-splat cooling in tube more even and the temperature of the corresponding location along the length of tubes lower. The appropriate increase of air-splat cooling velocity also can enhance the convection heat transfer between green bricks and air-splat cooling and further increase the cooling rate of green bricks, while an unreasonable rise in air-splat cooling velocity can cause the more serious difference in gas-flow velocity distribution along the width of kiln. Consequently, the more difference in temperature between both sides of kiln width occurs, which probably leads to several firing defects such as crack in brick, body tint and unevenness, etc.

Key words: splat cooling zone of roller hearth kiln; air-splat cooling velocity; velocity distribution; temperature distribution; numerical simulation