锌钡白回转窑消色力指标的波动性成因分析

消色力是锌钡白的关键质量指标，某锌钡白回转窑的消色力指标不稳定，用傅立叶方法发现其包含的谐波分量比较显著，表明消色力波动存在一定的周期性，针对消色力序列是一非平稳序列，为得到关于波动的更详细信息，进而采用HHT时频联合分析的方法，通过对其边际谱的研究得到比较精确的波动频率，通过Hilbert谱的分析实现对该波动的时间定位，为质量问题的追溯提供了线索和条件。

On the Fluctuation of Achromic Power in a Lithopone Rotary Kiln

Stable and high achromic power is the most important performance index of lithopone calcination. However, fluctuation of the power is unavoidable in a real lithopone rotary kiln because of disturbances. Fourier Transform (FT) indicates that there are harmonics in the power signal, but fails to describe its exact frequency properties because of the intrinsic non-stationarity of the signal. In order to deal with the non-stationarity, Hilbert-Huang Transform (HHT) is used to analyze the marginal spectrum and spatial time-frequency distribution of the signal. Compared with that of FT, the marginal spectrum of HHT provides much more accurate frequency distribution of the power signal, which exactly locates the frequencies of the harmonics. Moreover, the spatial time-frequency distribution provides detailed information, especially the time and duration, of the fluctuation, which helps to trace the quality accidents, and to explain the fluctuation of the process.