长回转窑能源浪费在回转窑中焙烧粉状产品已是一种不足为奇的老办法。但在1982年,对这种老办法花费很大(设备能源效率不高,因辐射而造成的热损失相当大)。此外,由于蒸汽和粉状产品之间的热交换不好自氧化铝焙烧窑排空的烟气温度高达250～300℃。可是,至今在各工业部门中仍有许多长回转窑在运行。它们的厂家不愿付出改造它们的费用,即使在石油危机的情况下也是同样。 Long rotary kiln Energy waste It is not surprising that the old method of baking powdered products in a rotary kiln has been used. In 1982, however, this old approach was costly (equipment was not energy efficient and heat loss due to radiation was considerable). In addition, the flue gas evacuated from the alumina roasting kiln can be as high as 250-300 ° C due to poor heat exchange between the steam and the powdered product. However, to date, many long rotary kilns still operate in various industrial sectors. Their manufacturers are reluctant to pay for retrofitting them, even in the case of the oil crisis.