Engineering and Applied Science Research (Sep 2023)
Application of solid media for enhancing the temperature distribution within a downdraft kiln during clay brick firing
Abstract
Industrial production of fired clay bricks typically experiences problems related to the brick quality such as insufficient-firing, over-burning, and distortion due to twisting, bulging, warping or cracking, which affect their color and strength. These issues are derived mainly from the poor temperature control and heat distribution. To mitigate this problem, a simple technique is proposed in this work by inserting solid media between bricks during the firing process. Three types of solid media including alumina balls, clay balls and sandstone sheets were tested. The use of the solid media was found to significantly (93%) improve the temperature distribution in the kiln. The temperature difference between the bottom and top bricks reduced from 344°C (without the solid media) to a minimum of 23°C when alumina balls were applied with the sandstone sheets. The properties of the bricks in terms of water absorption and shrinkage were found to be 11.3-11.9% and 1.3-1.6%, respectively, which are comparable with those of the commercial bricks. Interestingly, the compressive strength of the bricks produced with the aid of the solid media was enhanced significantly, especially when the sandstone sheets were used together with the alumina balls as the compressive strength was double that of the industrial bricks.
