回转窑能量配置的研究

On the energy distribution and disposition of the rotary kiln

在某水泥厂的实际生产条件下,结合热工标定现场采集的生产数据,采用试验分析和理论计算的方法讨论了回转窑内的能量配置情况。结果表明,回转窑系统内收入能量大于支出能量,能量为590.25 k J/kg,回转窑存在用煤量富余的情况,从能量角度说明了该水泥厂产量高的原因(设计产量为2 500 t/d,实际产量为3 180 t/d)。从生产整体分析,若将回转窑多余的用煤量用于分解炉内,不仅能为分解炉提供更多的热量,使入窑生料分解率得到提高,从而提高生产效率,还能在一定程度上降低回转窑的热负荷,延长回转窑的使用周期。

This paper would like to devote itself to the investigation and analysis of the energy distribution and disposition of a rotary kiln according to the data output of the thermal testing （basic parameters of the air into the kiln and basic production data） gained from the actual production of a cement plant. For this purpose, we have done the experimental analysis （the approximate analysis of the pulverized coal, the chemical composition of the clinker, the apparent decomposition rate of the raw material into the kiln, the gas composition and the gas-heating capacity） as well as the data gained through theoretical calculation （heat income and heat consumption）the energy config- uration in rotary kiln. The results of our analysis and experiments have shown that the energy input into the rotary kiln equals 1 708.77 kJ/mol, whereas the energy spent by the rotary kiln is equal to 1 118.52 kJ/mol. Thus, the energy input turns out to be 590.25 kJ/kg greater than the actual enei＇gy consumed. This literally means that the rotary kiln is coal-abundant and accounts for the higher energy output （The output of the energy total was 2 500 t/d, whereas the actual energy output was 3 180 t/d, thus, leaving 27.2% of the actual energy over that of the originally planned）. And, therefore, the coal apportionment ratio of the plant is 37.1：62.9, whereas the total data of the coal apportionment ratio was 40 ： 60. On the basis of our study findings, we can probably say that the mass of coal into the preealciner was raised, as the total mass of coal into the rotary kiln has been reduced. That is to say, the actual production results turn out to be advantageous of the coal apportionment ratio. Thus, the above discovered calculation results, the use of coal proves to be excessive in the rotary kiln. And, the coal apportionment ratio should be reduced within a reasonable range. The main task of precalclner is to decompose the raw material, and the decomposition needs a great mass of energy. Based on the analysis of the whole production sys- tem, it can be concluded that, if the excessive coal of rotary kiln were to be transferred to precaleiner, it could not only enhance the productivity by bringing more heat into pecalciner to promote the decomposition rate of the raw meal, but also helps to reduce the heat load of rotary kiln to some extent to prolong the service cycle of the rotary kiln.