Bricks are considered as one of the ceramics products which consume lots of energy. Therefore, the present paper aims to experimentally investigate the heat transfer and pressure drop of perforated bricks tunnel kiln. The porosity of the used perforated bricks is 4.6 %. A test section of scale 1:4 has been conducted. Ten different perforated bricks arrangements have been examined within Reynolds number range of 10,000 to 21,000. The results demonstrate that the heat transfer and pressure drop depends on setting arrangement. The longitudinal Nusselt number have a maximum decreases of setting 2 over setting 1 by about 21% as the space between columns increases from 26 to 68 mm at Re = 18,600. The Nusselt number for middle columns is higher than that near walls and the maximum enhancement in longitudinal direction is 36.6 % and in transversal directions 25.2% for settings 1 and 3 respectively. The presence of holes in the bricks increases the heat transfer in the transversal direction. Finally, an empirical correlation is obtained for the average Nusselt number (Nu) in terms of Reynolds number (Re), brick setting dimensionless groups (s/a), ( s/b). |
