Optimization of the heat flow in tunnel kilns

Utilization of energy in recuperative counterflow furnaces

“…Equation (1) cannot be applied to RCF, because in these plants qm" determines not the useful energy but the wasted energy lost with the discharged product. In operating RCF this item in the heat balance is small [5,6], and this is their undoubted advantage. We cannot use Eq.…”

Tunnel kiln for firing refractories at 1850�c

“…1. The kiln's length is 156 m; width of the channel, 3.2 m; and the setting height, 0.725 m. It is heated with natural gas with a minimum combustion heat of 8540 kcal/m 3 (with normal parameters).During reconstruction changes were made in the length of the production zones bearing in mind the features of heat and mass-exchange discovered during the research work [1,2]. In place of the preheat, firing, and cooling zones which previously took up 46.2, 15.3, and 38.5% of the kiln's length, we fixed zone lengths of 36.5, 15.3, and 48.2%.…”

“…In place of the preheat, firing, and cooling zones which previously took up 46.2, 15.3, and 38.5% of the kiln's length, we fixed zone lengths of 36.5, 15.3, and 48.2%. The section for heating the goods, 15 m in length, was moved into the cooling zone.The reconstruction of the walls in the firing zone consisted of replacing, at a depth of 0.7 m from the hot face, the structures built of MKhS, KhM and dinas insulating brick [3], respectively, by MKhVP, MKhS, and corundum insulating bricks KL-1.3 (ChMTU-9-84-68); the roof was made of MKhVP articles, and insulated with chrome--magnesite filling fractions 0-3 nun and kaolin wool, the thickness of the heat-insulating layer being about 140 mm. Burner ports were made in the kiln walls with the optimum profile calculated for burners whose flame can be regulated.…”